675174d4ba
Move netlink routines to their own file, and use netlink to configure or fetch all the information we need, except for the TUNSETIFF ioctl. Move pasta-specific functions to their own file as well, add parameters and calls to configure the tap interface in the namespace. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
3852 lines
102 KiB
C
3852 lines
102 KiB
C
// SPDX-License-Identifier: AGPL-3.0-or-later
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/* PASST - Plug A Simple Socket Transport
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* for qemu/UNIX domain socket mode
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*
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* PASTA - Pack A Subtle Tap Abstraction
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* for network namespace/tap device mode
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*
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* tcp.c - TCP L2-L4 translation state machine
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*
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* Copyright (c) 2020-2021 Red Hat GmbH
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* Author: Stefano Brivio <sbrivio@redhat.com>
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*/
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/**
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* DOC: Theory of Operation
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*
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*
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* PASST mode
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* ==========
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*
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* This implementation maps TCP traffic between a single L2 interface (tap) and
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* native TCP (L4) sockets, mimicking and reproducing as closely as possible the
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* inferred behaviour of applications running on a guest, connected via said L2
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* interface. Four connection flows are supported:
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* - from the local host to the guest behind the tap interface:
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* - this is the main use case for proxies in service meshes
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* - we bind to configured local ports, and relay traffic between L4 sockets
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* with local endpoints and the L2 interface
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* - from remote hosts to the guest behind the tap interface:
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* - this might be needed for services that need to be addressed directly,
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* and typically configured with special port forwarding rules (which are
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* not needed here)
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* - we also relay traffic between L4 sockets with remote endpoints and the L2
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* interface
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* - from the guest to the local host:
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* - this is not observed in practice, but implemented for completeness and
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* transparency
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* - from the guest to external hosts:
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* - this might be needed for applications running on the guest that need to
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* directly access internet services (e.g. NTP)
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*
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* Relevant goals are:
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* - transparency: sockets need to behave as if guest applications were running
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* directly on the host. This is achieved by:
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* - avoiding port and address translations whenever possible
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* - mirroring TCP dynamics by observation of socket parameters (TCP_INFO
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* socket option) and TCP headers of packets coming from the tap interface,
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* reapplying those parameters in both flow directions (including TCP_MSS,
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* TCP_WINDOW_CLAMP socket options)
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* - simplicity: only a small subset of TCP logic is implemented here and
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* delegated as much as possible to the TCP implementations of guest and host
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* kernel. This is achieved by:
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* - avoiding a complete TCP stack reimplementation, with a modified TCP state
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* machine focused on the translation of observed states instead
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* - mirroring TCP dynamics as described above and hence avoiding the need for
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* segmentation, explicit queueing, and reassembly of segments
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* - security:
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* - no dynamic memory allocation is performed
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* - TODO: synflood protection
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*
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* Portability is limited by usage of Linux-specific socket options.
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*
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*
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* Limits
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* ------
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*
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* To avoid the need for dynamic memory allocation, a maximum, reasonable amount
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* of connections is defined by MAX_TAP_CONNS below (currently 128k).
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*
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* Data needs to linger on sockets as long as it's not acknowledged by the
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* guest, and is read using MSG_PEEK into preallocated static buffers sized
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* to the maximum supported window, 64MiB ("discard" buffer, for already-sent
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* data) plus a number of maximum-MSS-sized buffers. This imposes a practical
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* limitation on window scaling, that is, the maximum factor is 1024. Larger
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* factors will be accepted, but resulting, larger values are never advertised
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* to the other side, and not used while queueing data.
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*
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*
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* Ports
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* -----
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*
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* To avoid the need for ad-hoc configuration of port forwarding or allowed
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* ports, listening sockets can be opened and bound to all unbound ports on the
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* host, as far as process capabilities allow. This service needs to be started
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* after any application proxy that needs to bind to local ports. Mapped ports
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* can also be configured explicitly.
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*
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* No port translation is needed for connections initiated remotely or by the
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* local host: source port from socket is reused while establishing connections
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* to the guest.
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*
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* For connections initiated by the guest, it's not possible to force the same
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* source port as connections are established by the host kernel: that's the
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* only port translation needed.
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*
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*
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* Connection tracking and storage
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* -------------------------------
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*
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* Connections are tracked by the @tt array of struct tcp_tap_conn, containing
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* addresses, ports, TCP states and parameters. This is statically allocated and
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* indexed by an arbitrary connection number. The array is compacted whenever a
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* connection is closed, by remapping the highest connection index in use to the
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* one freed up.
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*
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* References used for the epoll interface report the connection index used for
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* the @tt array.
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*
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* IPv4 addresses are stored as IPv4-mapped IPv6 addresses to avoid the need for
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* separate data structures depending on the protocol version.
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*
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* - Inbound connection requests (to the guest) are mapped using the triple
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* < source IP address, source port, destination port >
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* - Outbound connection requests (from the guest) are mapped using the triple
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* < destination IP address, destination port, source port >
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* where the source port is the one used by the guest, not the one used by the
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* corresponding host socket
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*
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*
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* Initialisation
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* --------------
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*
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* Up to 2^15 + 2^14 listening sockets (excluding ephemeral ports, repeated for
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* IPv4 and IPv6) can be opened and bound to wildcard addresses. Some will fail
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* to bind (for low ports, or ports already bound, e.g. by a proxy). These are
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* added to the epoll list, with no separate storage.
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*
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*
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* States and events
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* -----------------
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*
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* These states apply to connected sockets only, listening sockets are always
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* open after initialisation, in LISTEN state. A single state is maintained for
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* both sides of the connection, and some states are omitted as they are already
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* handled by host kernel and guest.
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*
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* - CLOSED no connection
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* No associated events: this is always a final state, new connections
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* directly start from TAP_SYN_SENT or SOCK_SYN_SENT described below.
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*
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* - TAP_SYN_SENT connect() in progress, triggered from tap
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* - connect() completes SYN,ACK to tap > TAP_SYN_RCVD
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* - connect() aborts RST to tap, close socket > CLOSED
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*
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* - SOCK_SYN_SENT new connected socket, SYN sent to tap
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* - SYN,ACK from tap ACK to tap > ESTABLISHED
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* - SYN,ACK timeout RST to tap, close socket > CLOSED
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*
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* - TAP_SYN_RCVD connect() completed, SYN,ACK sent to tap
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* - FIN from tap write shutdown > FIN_WAIT_1
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* - ACK from tap > ESTABLISHED
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* - ACK timeout RST to tap, close socket > CLOSED
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*
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* - ESTABLISHED connection established, ready for data
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* - EPOLLRDHUP read shutdown > ESTABLISHED_SOCK_FIN
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* - FIN from tap write shutdown > FIN_WAIT_1
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* - EPOLLHUP RST to tap, close socket > CLOSED
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* - data timeout read shutdown, FIN to tap >
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* ESTABLISHED_SOCK_FIN_SENT
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*
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* - ESTABLISHED_SOCK_FIN socket closing connection, reading half closed
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* - zero-sized socket read FIN,ACK to tap > ESTABLISHED_SOCK_FIN_SENT
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*
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* - ESTABLISHED_SOCK_FIN_SENT socket closing connection, FIN sent to tap
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* - ACK (for FIN) from tap > CLOSE_WAIT
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* - tap ACK timeout RST to tap, close socket > CLOSED
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*
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* - CLOSE_WAIT socket closing connection, ACK from tap
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* - FIN from tap write shutdown > LAST_ACK
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* - data timeout RST to tap, close socket > CLOSED
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*
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* - LAST_ACK socket started close, tap completed it
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* - any event from socket ACK to tap, close socket > CLOSED
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* - ACK timeout RST to tap, close socket > CLOSED
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*
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* - FIN_WAIT_1 tap closing connection, FIN sent to socket
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* - EPOLLRDHUP FIN,ACK to tap, shutdown > FIN_WAIT_1_SOCK_FIN
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* - socket timeout RST to tap, close socket > CLOSED
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*
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* - FIN_WAIT_1_SOCK_FIN tap closing connection, FIN received from socket
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* - ACK from tap close socket > CLOSED
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* - tap ACK timeout RST to tap, close socket > CLOSED
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*
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* - from any state
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* - RST from tap close socket > CLOSED
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* - socket error RST to tap, close socket > CLOSED
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*
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* Connection setup
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* ----------------
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*
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* - inbound connection (from socket to guest): on accept() from listening
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* socket, the new socket is mapped in connection tracking table, and
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* three-way handshake initiated towards the guest, advertising MSS and window
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* size and scaling from socket parameters
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* - outbound connection (from guest to socket): on SYN segment from guest, a
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* new socket is created and mapped in connection tracking table, setting
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* MSS and window clamping from header and option of the observed SYN segment
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*
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*
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* Aging and timeout
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* -----------------
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*
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* A bitmap of TCP_MAX_CONNS bits indicate the connections subject to timed
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* events based on states:
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* - SOCK_SYN_SENT: after a 2MSL (240s) timeout waiting for a SYN,ACK segment
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* from tap expires, connection is reset (RST to tap, socket closed)
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* - TAP_SYN_RCVD: after a 2MSL (240s) timeout waiting for an ACK segment from
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* tap expires, connection is reset (RST to tap, socket closed)
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* - TAP_SYN_SENT: connect() is pending, timeout is handled implicitly by
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* connect() timeout, connection will be reset in case
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* - ESTABLISHED, ESTABLISHED_SOCK_FIN: if an ACK segment to tap is pending,
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* bytes acknowledged by socket endpoint are checked every 50ms (one quarter
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* of current TCP_DELACK_MAX on Linux)
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* - ESTABLISHED, ESTABLISHED_SOCK_FIN: after a timeout of 3s (TODO: implement
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* requirements from RFC 6298) waiting for an ACK segment from tap expires,
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* data from socket queue is retransmitted starting from the last ACK sequence
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* - ESTABLISHED, ESTABLISHED_SOCK_FIN: after a two hours (current
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* TCP_KEEPALIVE_TIME on Linux) timeout waiting for any activity expires,
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* connection is reset (RST to tap, socket closed)
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* - ESTABLISHED_SOCK_FIN: after a 2MSL (240s) timeout waiting for an ACK
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* segment from tap expires, connection is reset (RST to tap, socket closed)
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* - CLOSE_WAIT: after a 2MSL (240s) timeout waiting for a FIN segment from tap
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* expires, connection is reset (RST to tap, socket closed)
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* - FIN_WAIT_1: after a 2MSL (240s) timeout waiting for an ACK segment from
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* socet expires, connection is reset (RST to tap, socket closed)
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* - FIN_WAIT_1_SOCK_FIN: after a 2MSL (240s) timeout waiting for an ACK segment
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* from tap expires, connection is reset (RST to tap, socket closed)
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* - LAST_ACK: after a 2MSL (240s) timeout waiting for an ACK segment from
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* socket expires, connection is reset (RST to tap, socket closed)
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*
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*
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* Data flows (from ESTABLISHED, ESTABLISHED_SOCK_FIN states)
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* ----------------------------------------------------------
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*
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* @seq_to_tap: next sequence for packets to tap
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* @seq_ack_from_tap: last ACK number received from tap
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* @seq_from_tap: next sequence for packets from tap (not actually sent)
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* @seq_ack_to_tap: last ACK number sent to tap
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*
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* @seq_init_from_tap: initial sequence number from tap
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*
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* @wnd_from_tap: last window size received from tap, scaled
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*
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* - from socket to tap:
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* - on new data from socket:
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* - peek into buffer
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* - send data to tap:
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* - starting at offset (@seq_to_tap - @seq_ack_from_tap)
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* - in MSS-sized segments
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* - increasing @seq_to_tap at each segment
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* - up to window (until @seq_to_tap - @seq_ack_from_tap <= @wnd_from_tap)
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* - mark socket in bitmap for periodic ACK check, set @last_ts_to_tap
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* - on read error, send RST to tap, close socket
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* - on zero read, send FIN to tap, enter ESTABLISHED_SOCK_FIN
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* - on ACK from tap:
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* - set @ts_ack_tap
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* - check if it's the second duplicated ACK
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* - consume buffer by difference between new ack_seq and @seq_ack_from_tap
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* - update @seq_ack_from_tap from ack_seq in header
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* - on two duplicated ACKs, reset @seq_to_tap to @seq_ack_from_tap, and
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* resend with steps listed above
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* - set TCP_WINDOW_CLAMP from TCP header from tap
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* - on @seq_ack_from_tap == @seq_to_tap, mark in bitmap, umark otherwise
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* - periodically:
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* - if @seq_ack_from_tap < @seq_to_tap and the retransmission timer
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* (TODO: implement requirements from RFC 6298, currently 3s fixed) from
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* @ts_tap_from_ack elapsed, reset @seq_to_tap to @seq_ack_from_tap, and
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* resend data with the steps listed above
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*
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* - from tap to socket:
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* - on packet from tap:
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* - set @ts_tap_ack
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* - set TCP_WINDOW_CLAMP from TCP header from tap
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* - check seq from header against @seq_from_tap, if data is missing, send
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* two ACKs with number @seq_ack_to_tap, discard packet
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* - otherwise queue data to socket, set @seq_from_tap to seq from header
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* plus payload length
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* - in ESTABLISHED state, send ACK to tap as soon as we queue to the
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* socket. In other states, query socket for TCP_INFO, set
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* @seq_ack_to_tap to (tcpi_bytes_acked + @seq_init_from_tap) % 2^32 and
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* send ACK to tap
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*
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*
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* PASTA mode
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* ==========
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*
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* For traffic directed to TCP ports configured for mapping to the tuntap device
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* in the namespace, and for non-local traffic coming from the tuntap device,
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* the implementation is identical as the PASST mode described in the previous
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* section.
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*
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* For local traffic directed to TCP ports configured for direct mapping between
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* namespaces, the implementation is substantially simpler: packets are directly
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* translated between L4 sockets using a pair of splice() syscalls. These
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* connections are tracked in the @ts array of struct tcp_splice_conn, using
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* these states:
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*
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* - CLOSED: no connection
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* - SPLICE_ACCEPTED: accept() on the listening socket succeeded
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* - SPLICE_CONNECT: connect() issued in the destination namespace
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* - SPLICE_ESTABLISHED: connect() succeeded, packets are transferred
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* - SPLICE_FIN_FROM: FIN (EPOLLRDHUP) seen from originating socket
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* - SPLICE_FIN_TO: FIN (EPOLLRDHUP) seen from connected socket
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* - SPLICE_FIN_BOTH: FIN (EPOLLRDHUP) seen from both sides
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*/
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#define _GNU_SOURCE
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#include <sched.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <errno.h>
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#include <limits.h>
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#include <net/ethernet.h>
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#include <net/if.h>
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#include <netinet/in.h>
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#include <stdint.h>
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#include <stddef.h>
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#include <string.h>
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#include <sys/epoll.h>
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#include <sys/random.h>
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#include <sys/socket.h>
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#include <sys/types.h>
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#include <sys/uio.h>
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#include <unistd.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/tcp.h>
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#include <time.h>
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#include "checksum.h"
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#include "util.h"
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#include "passt.h"
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#include "tap.h"
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#include "siphash.h"
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#include "pcap.h"
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#include "conf.h"
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#define MAX_TAP_CONNS (128 * 1024)
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#define MAX_SPLICE_CONNS (128 * 1024)
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#define TCP_TAP_FRAMES 64
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#define MAX_PIPE_SIZE (2 * 1024 * 1024)
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#define TCP_HASH_TABLE_LOAD 70 /* % */
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#define TCP_HASH_TABLE_SIZE (MAX_TAP_CONNS * 100 / \
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TCP_HASH_TABLE_LOAD)
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#define MAX_WS 10
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#define MAX_WINDOW (1 << (16 + (MAX_WS)))
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#define MSS_DEFAULT 536
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#define WINDOW_DEFAULT 14600 /* RFC 6928 */
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#define SYN_TIMEOUT 240000 /* ms */
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#define ACK_TIMEOUT 2000
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#define ACK_INTERVAL 50
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#define ACT_TIMEOUT 7200000
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#define FIN_TIMEOUT 240000
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#define LAST_ACK_TIMEOUT 240000
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#define TCP_SOCK_POOL_SIZE 32
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#define TCP_SOCK_POOL_TSH 16 /* Refill in ns if > x used */
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#define TCP_SPLICE_PIPE_POOL_SIZE 256
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#define REFILL_INTERVAL 1000
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#define PORT_DETECT_INTERVAL 1000
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#define LOW_RTT_TABLE_SIZE 8
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#define LOW_RTT_THRESHOLD 10 /* us */
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/* We need to include <linux/tcp.h> for tcpi_bytes_acked, instead of
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* <netinet/tcp.h>, but that doesn't include a definition for SOL_TCP
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*/
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#define SOL_TCP IPPROTO_TCP
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#define SEQ_LE(a, b) ((b) - (a) < MAX_WINDOW)
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#define SEQ_LT(a, b) ((b) - (a) - 1 < MAX_WINDOW)
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#define SEQ_GE(a, b) ((a) - (b) < MAX_WINDOW)
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#define SEQ_GT(a, b) ((a) - (b) - 1 < MAX_WINDOW)
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#define CONN_V4(conn) (IN6_IS_ADDR_V4MAPPED(&conn->a.a6))
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#define CONN_V6(conn) (!CONN_V4(conn))
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enum tcp_state {
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CLOSED = 0,
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TAP_SYN_SENT,
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SOCK_SYN_SENT,
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TAP_SYN_RCVD,
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ESTABLISHED,
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ESTABLISHED_SOCK_FIN,
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ESTABLISHED_SOCK_FIN_SENT,
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CLOSE_WAIT,
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LAST_ACK,
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FIN_WAIT_1,
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FIN_WAIT_1_SOCK_FIN,
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SPLICE_ACCEPTED,
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SPLICE_CONNECT,
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SPLICE_ESTABLISHED,
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SPLICE_FIN_FROM,
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SPLICE_FIN_TO,
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SPLICE_FIN_BOTH,
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};
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#define TCP_STATE_STR_SIZE (SPLICE_FIN_BOTH + 1)
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static char *tcp_state_str[TCP_STATE_STR_SIZE] __attribute((__unused__)) = {
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"CLOSED", "TAP_SYN_SENT", "SOCK_SYN_SENT", "TAP_SYN_RCVD",
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"ESTABLISHED", "ESTABLISHED_SOCK_FIN", "ESTABLISHED_SOCK_FIN_SENT",
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"CLOSE_WAIT", "LAST_ACK", "FIN_WAIT_1", "FIN_WAIT_1_SOCK_FIN",
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"SPLICE_ACCEPTED", "SPLICE_CONNECT", "SPLICE_ESTABLISHED",
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"SPLICE_FIN_FROM", "SPLICE_FIN_TO", "SPLICE_FIN_BOTH",
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};
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#define FIN (1 << 0)
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#define SYN (1 << 1)
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#define RST (1 << 2)
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#define ACK (1 << 4)
|
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/* Flags for internal usage */
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#define DUP_ACK (1 << 5)
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#define FORCE_ACK (1 << 6)
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#define OPT_EOL 0
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#define OPT_NOP 1
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#define OPT_MSS 2
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#define OPT_MSS_LEN 4
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#define OPT_WS 3
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#define OPT_WS_LEN 3
|
|
#define OPT_SACKP 4
|
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#define OPT_SACK 5
|
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#define OPT_TS 8
|
|
|
|
struct tcp_tap_conn;
|
|
|
|
/**
|
|
* struct tcp_tap_conn - Descriptor for a TCP connection via tap (not spliced)
|
|
* @next: Pointer to next item in hash chain, if any
|
|
* @sock: Socket descriptor number
|
|
* @hash_bucket: Bucket index in connection lookup hash table
|
|
* @a.a6: IPv6 remote address, can be IPv4-mapped
|
|
* @a.a4.zero: Zero prefix for IPv4-mapped, see RFC 6890, Table 20
|
|
* @a.a4.one: Ones prefix for IPv4-mapped
|
|
* @a.a4.a: IPv4 address
|
|
* @tap_port: Guest-facing tap port
|
|
* @sock_port: Remote, socket-facing port
|
|
* @local: Destination is local
|
|
* @state: TCP connection state
|
|
* @seq_to_tap: Next sequence for packets to tap
|
|
* @seq_ack_from_tap: Last ACK number received from tap
|
|
* @seq_from_tap: Next sequence for packets from tap (not actually sent)
|
|
* @seq_ack_to_tap: Last ACK number sent to tap
|
|
* @seq_dup_ack: Last duplicate ACK number sent to tap
|
|
* @seq_init_from_tap: Initial sequence number from tap
|
|
* @seq_init_from_tap: Initial sequence number to tap
|
|
* @ws_tap: Window scaling factor from tap
|
|
* @ws: Window scaling factor
|
|
* @wnd_from_tap: Last window size received from tap, scaled
|
|
* @wnd_to_tap: Socket-side sending window, advertised to tap
|
|
* @window_clamped: Window was clamped on socket at least once
|
|
* @ts_sock_act: Last activity timestamp from socket for timeout purposes
|
|
* @ts_tap_act: Last activity timestamp from tap for timeout purposes
|
|
* @ts_ack_from_tap: Last ACK segment timestamp from tap
|
|
* @ts_ack_to_tap: Last ACK segment timestamp to tap
|
|
* @tap_data_noack: Last unacked data to tap, set to { 0, 0 } on ACK
|
|
* @mss_guest: Maximum segment size advertised by guest
|
|
* @events: epoll events currently enabled for socket
|
|
*/
|
|
struct tcp_tap_conn {
|
|
struct tcp_tap_conn *next;
|
|
int sock;
|
|
int hash_bucket;
|
|
|
|
union {
|
|
struct in6_addr a6;
|
|
struct {
|
|
uint8_t zero[10];
|
|
uint8_t one[2];
|
|
struct in_addr a;
|
|
} a4;
|
|
} a;
|
|
in_port_t tap_port;
|
|
in_port_t sock_port;
|
|
int local;
|
|
enum tcp_state state;
|
|
|
|
uint32_t seq_to_tap;
|
|
uint32_t seq_ack_from_tap;
|
|
uint32_t seq_from_tap;
|
|
uint32_t seq_ack_to_tap;
|
|
uint32_t seq_dup_ack;
|
|
uint32_t seq_init_from_tap;
|
|
uint32_t seq_init_to_tap;
|
|
|
|
uint16_t ws_tap;
|
|
uint16_t ws;
|
|
uint32_t wnd_from_tap;
|
|
uint32_t wnd_to_tap;
|
|
int window_clamped;
|
|
int snd_buf;
|
|
|
|
struct timespec ts_sock_act;
|
|
struct timespec ts_tap_act;
|
|
struct timespec ts_ack_from_tap;
|
|
struct timespec ts_ack_to_tap;
|
|
struct timespec tap_data_noack;
|
|
|
|
int mss_guest;
|
|
|
|
uint32_t events;
|
|
};
|
|
|
|
/**
|
|
* struct tcp_splice_conn - Descriptor for a spliced TCP connection
|
|
* @from: File descriptor number of socket for accepted connection
|
|
* @pipe_from_to: Pipe ends for splice() from @from to @to
|
|
* @to: File descriptor number of peer connected socket
|
|
* @pipe_to_from: Pipe ends for splice() from @to to @from
|
|
* @state: TCP connection state
|
|
*/
|
|
struct tcp_splice_conn {
|
|
int from;
|
|
int pipe_from_to[2];
|
|
int to;
|
|
int pipe_to_from[2];
|
|
enum tcp_state state;
|
|
int from_fin_sent;
|
|
int to_fin_sent;
|
|
int v6;
|
|
uint64_t from_read;
|
|
uint64_t from_written;
|
|
uint64_t to_read;
|
|
uint64_t to_written;
|
|
};
|
|
|
|
/* Port re-mappings as delta, indexed by original destination port */
|
|
static in_port_t tcp_port_delta_to_tap [USHRT_MAX];
|
|
static in_port_t tcp_port_delta_to_init [USHRT_MAX];
|
|
|
|
/* Listening sockets, used for automatic port forwarding in pasta mode only */
|
|
static int tcp_sock_init_lo [USHRT_MAX][IP_VERSIONS];
|
|
static int tcp_sock_init_ext [USHRT_MAX][IP_VERSIONS];
|
|
static int tcp_sock_ns [USHRT_MAX][IP_VERSIONS];
|
|
|
|
/* Table of destinations with very low RTT (assumed to be local), LRU */
|
|
static struct in6_addr low_rtt_dst[LOW_RTT_TABLE_SIZE];
|
|
|
|
/**
|
|
* tcp_remap_to_tap() - Set delta for port translation toward guest/tap
|
|
* @port: Original destination port, host order
|
|
* @delta: Delta to be added to original destination port
|
|
*/
|
|
void tcp_remap_to_tap(in_port_t port, in_port_t delta)
|
|
{
|
|
tcp_port_delta_to_tap[port] = delta;
|
|
}
|
|
|
|
/**
|
|
* tcp_remap_to_tap() - Set delta for port translation toward init namespace
|
|
* @port: Original destination port, host order
|
|
* @delta: Delta to be added to original destination port
|
|
*/
|
|
void tcp_remap_to_init(in_port_t port, in_port_t delta)
|
|
{
|
|
tcp_port_delta_to_init[port] = delta;
|
|
}
|
|
|
|
/* Static buffers */
|
|
|
|
/**
|
|
* tcp4_l2_buf_t - Pre-cooked IPv4 packet buffers for tap connections
|
|
* @psum: Partial IP header checksum (excluding tot_len and saddr)
|
|
* @tsum: Partial TCP header checksum (excluding length and saddr)
|
|
* @pad: Align TCP header to 32 bytes, for AVX2 checksum calculation only
|
|
* @vnet_len: 4-byte qemu vnet buffer length descriptor, only for passt mode
|
|
* @eh: Pre-filled Ethernet header
|
|
* @iph: Pre-filled IP header (except for tot_len and saddr)
|
|
* @uh: Headroom for TCP header
|
|
* @data: Storage for TCP payload
|
|
*/
|
|
static struct tcp4_l2_buf_t {
|
|
uint32_t psum; /* 0 */
|
|
uint32_t tsum; /* 4 */
|
|
#ifdef __AVX2__
|
|
uint8_t pad[18]; /* 8, align th to 32 bytes */
|
|
#endif
|
|
|
|
uint32_t vnet_len; /* 26 */
|
|
struct ethhdr eh; /* 30 */
|
|
struct iphdr iph; /* 44 */
|
|
struct tcphdr th; /* 64 */
|
|
uint8_t data[USHRT_MAX - sizeof(struct tcphdr)];
|
|
#ifdef __AVX2__
|
|
} __attribute__ ((packed, aligned(32)))
|
|
#else
|
|
} __attribute__ ((packed, aligned(__alignof__(unsigned int))))
|
|
#endif
|
|
tcp4_l2_buf[TCP_TAP_FRAMES];
|
|
|
|
static int tcp4_l2_buf_mss;
|
|
static int tcp4_l2_buf_mss_nr_set;
|
|
static int tcp4_l2_buf_mss_tap;
|
|
static int tcp4_l2_buf_mss_tap_nr_set;
|
|
|
|
/**
|
|
* tcp6_l2_buf_t - Pre-cooked IPv6 packet buffers for tap connections
|
|
* @pad: Align IPv6 header for checksum calculation to 32B (AVX2) or 4B
|
|
* @vnet_len: 4-byte qemu vnet buffer length descriptor, only for passt mode
|
|
* @eh: Pre-filled Ethernet header
|
|
* @ip6h: Pre-filled IP header (except for payload_len and addresses)
|
|
* @th: Headroom for TCP header
|
|
* @data: Storage for TCP payload
|
|
*/
|
|
struct tcp6_l2_buf_t {
|
|
#ifdef __AVX2__
|
|
uint8_t pad[14]; /* 0 align ip6h to 32 bytes */
|
|
#else
|
|
uint8_t pad[2]; /* align ip6h to 4 bytes 0 */
|
|
#endif
|
|
uint32_t vnet_len; /* 14 2 */
|
|
struct ethhdr eh; /* 18 6 */
|
|
struct ipv6hdr ip6h; /* 32 20 */
|
|
struct tcphdr th; /* 72 60 */
|
|
uint8_t data[USHRT_MAX -
|
|
(sizeof(struct ipv6hdr) + sizeof(struct tcphdr))];
|
|
#ifdef __AVX2__
|
|
} __attribute__ ((packed, aligned(32)))
|
|
#else
|
|
} __attribute__ ((packed, aligned(__alignof__(unsigned int))))
|
|
#endif
|
|
tcp6_l2_buf[TCP_TAP_FRAMES];
|
|
|
|
static int tcp6_l2_buf_mss;
|
|
static int tcp6_l2_buf_mss_nr_set;
|
|
static int tcp6_l2_buf_mss_tap;
|
|
static int tcp6_l2_buf_mss_tap_nr_set;
|
|
|
|
/* recvmsg()/sendmsg() data for tap */
|
|
static struct iovec tcp4_l2_iov_sock [TCP_TAP_FRAMES + 1];
|
|
static struct iovec tcp6_l2_iov_sock [TCP_TAP_FRAMES + 1];
|
|
static char tcp_buf_discard [MAX_WINDOW];
|
|
|
|
static struct iovec tcp4_l2_iov_tap [TCP_TAP_FRAMES];
|
|
static struct iovec tcp6_l2_iov_tap [TCP_TAP_FRAMES];
|
|
static struct iovec tcp4_l2_flags_iov_tap [TCP_TAP_FRAMES];
|
|
static struct iovec tcp6_l2_flags_iov_tap [TCP_TAP_FRAMES];
|
|
|
|
static struct msghdr tcp4_l2_mh_sock;
|
|
static struct msghdr tcp6_l2_mh_sock;
|
|
|
|
static struct mmsghdr tcp_l2_mh_tap [TCP_TAP_FRAMES];
|
|
|
|
/* sendmsg() to socket */
|
|
static struct iovec tcp_tap_iov [UIO_MAXIOV];
|
|
|
|
/**
|
|
* tcp4_l2_flags_buf_t - IPv4 packet buffers for segments without data (flags)
|
|
* @psum: Partial IP header checksum (excluding tot_len and saddr)
|
|
* @tsum: Partial TCP header checksum (excluding length and saddr)
|
|
* @pad: Align TCP header to 32 bytes, for AVX2 checksum calculation only
|
|
* @vnet_len: 4-byte qemu vnet buffer length descriptor, only for passt mode
|
|
* @eh: Pre-filled Ethernet header
|
|
* @iph: Pre-filled IP header (except for tot_len and saddr)
|
|
* @th: Headroom for TCP header
|
|
* @opts: Headroom for TCP options
|
|
*/
|
|
static struct tcp4_l2_flags_buf_t {
|
|
uint32_t psum; /* 0 */
|
|
uint32_t tsum; /* 4 */
|
|
#ifdef __AVX2__
|
|
uint8_t pad[18]; /* 8, align th to 32 bytes */
|
|
#endif
|
|
|
|
uint32_t vnet_len; /* 26 */
|
|
struct ethhdr eh; /* 30 */
|
|
struct iphdr iph; /* 44 */
|
|
struct tcphdr th /* 64 */ __attribute__ ((aligned(4)));
|
|
char opts[OPT_MSS_LEN + OPT_WS_LEN + 1];
|
|
#ifdef __AVX2__
|
|
} __attribute__ ((packed, aligned(32)))
|
|
#else
|
|
} __attribute__ ((packed, aligned(__alignof__(unsigned int))))
|
|
#endif
|
|
tcp4_l2_flags_buf[TCP_TAP_FRAMES];
|
|
|
|
static int tcp4_l2_flags_buf_used;
|
|
|
|
/**
|
|
* tcp6_l2_flags_buf_t - IPv6 packet buffers for segments without data (flags)
|
|
* @pad: Align IPv6 header for checksum calculation to 32B (AVX2) or 4B
|
|
* @vnet_len: 4-byte qemu vnet buffer length descriptor, only for passt mode
|
|
* @eh: Pre-filled Ethernet header
|
|
* @ip6h: Pre-filled IP header (except for payload_len and addresses)
|
|
* @th: Headroom for TCP header
|
|
* @opts: Headroom for TCP options
|
|
*/
|
|
static struct tcp6_l2_flags_buf_t {
|
|
#ifdef __AVX2__
|
|
uint8_t pad[14]; /* 0 align ip6h to 32 bytes */
|
|
#else
|
|
uint8_t pad[2]; /* align ip6h to 4 bytes 0 */
|
|
#endif
|
|
uint32_t vnet_len; /* 14 2 */
|
|
struct ethhdr eh; /* 18 6 */
|
|
struct ipv6hdr ip6h; /* 32 20 */
|
|
struct tcphdr th /* 72 */ __attribute__ ((aligned(4))); /* 60 */
|
|
char opts[OPT_MSS_LEN + OPT_WS_LEN + 1];
|
|
#ifdef __AVX2__
|
|
} __attribute__ ((packed, aligned(32)))
|
|
#else
|
|
} __attribute__ ((packed, aligned(__alignof__(unsigned int))))
|
|
#endif
|
|
tcp6_l2_flags_buf[TCP_TAP_FRAMES];
|
|
|
|
static int tcp6_l2_flags_buf_used;
|
|
|
|
/* SO_RCVLOWAT set on source ([0]) or destination ([1]) socket, and activity */
|
|
static uint8_t splice_rcvlowat_set[MAX_SPLICE_CONNS / 8][2];
|
|
static uint8_t splice_rcvlowat_act[MAX_SPLICE_CONNS / 8][2];
|
|
|
|
/* TCP connections */
|
|
static struct tcp_tap_conn tt[MAX_TAP_CONNS];
|
|
static struct tcp_splice_conn ts[MAX_SPLICE_CONNS];
|
|
|
|
/* Table for lookup from remote address, local port, remote port */
|
|
static struct tcp_tap_conn *tt_hash[TCP_HASH_TABLE_SIZE];
|
|
|
|
/* Pools for pre-opened sockets and pipes */
|
|
static int splice_pipe_pool [TCP_SPLICE_PIPE_POOL_SIZE][2][2];
|
|
static int init_sock_pool4 [TCP_SOCK_POOL_SIZE];
|
|
static int init_sock_pool6 [TCP_SOCK_POOL_SIZE];
|
|
static int ns_sock_pool4 [TCP_SOCK_POOL_SIZE];
|
|
static int ns_sock_pool6 [TCP_SOCK_POOL_SIZE];
|
|
|
|
/**
|
|
* tcp_rtt_dst_low() - Check if low RTT was seen for connection endpoint
|
|
* @conn: Connection pointer
|
|
* Return: 1 if destination is in low RTT table, 0 otherwise
|
|
*/
|
|
static int tcp_rtt_dst_low(struct tcp_tap_conn *conn)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < LOW_RTT_TABLE_SIZE; i++)
|
|
if (!memcmp(&conn->a.a6, low_rtt_dst + i, sizeof(conn->a.a6)))
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tcp_rtt_dst_check() - Check tcpi_min_rtt, insert endpoint in table if low
|
|
* @conn: Connection pointer
|
|
* @info: Pointer to struct tcp_info for socket
|
|
*/
|
|
static void tcp_rtt_dst_check(struct tcp_tap_conn *conn, struct tcp_info *info)
|
|
{
|
|
int i, hole = -1;
|
|
|
|
if (!info->tcpi_min_rtt || (int)info->tcpi_min_rtt > LOW_RTT_THRESHOLD)
|
|
return;
|
|
|
|
for (i = 0; i < LOW_RTT_TABLE_SIZE; i++) {
|
|
if (!memcmp(&conn->a.a6, low_rtt_dst + i, sizeof(conn->a.a6)))
|
|
return;
|
|
if (hole == -1 && IN6_IS_ADDR_UNSPECIFIED(low_rtt_dst + i))
|
|
hole = i;
|
|
}
|
|
|
|
memcpy(low_rtt_dst + hole++, &conn->a.a6, sizeof(conn->a.a6));
|
|
if (hole == LOW_RTT_TABLE_SIZE)
|
|
hole = 0;
|
|
memcpy(low_rtt_dst + hole, &in6addr_any, sizeof(conn->a.a6));
|
|
}
|
|
|
|
/**
|
|
* tcp_tap_state() - Set given TCP state for tap connection, report to stderr
|
|
* @conn: Connection pointer
|
|
* @state: New TCP state to be set
|
|
*/
|
|
static void tcp_tap_state(struct tcp_tap_conn *conn, enum tcp_state state)
|
|
{
|
|
debug("TCP: socket %i: %s -> %s",
|
|
conn->sock, tcp_state_str[conn->state], tcp_state_str[state]);
|
|
conn->state = state;
|
|
}
|
|
|
|
/**
|
|
* tcp_splice_state() - Set state for spliced connection, report to stderr
|
|
* @conn: Connection pointer
|
|
* @state: New TCP state to be set
|
|
*/
|
|
static void tcp_splice_state(struct tcp_splice_conn *conn, enum tcp_state state)
|
|
{
|
|
debug("TCP: index %i: %s -> %s",
|
|
conn - ts, tcp_state_str[conn->state], tcp_state_str[state]);
|
|
conn->state = state;
|
|
}
|
|
|
|
/**
|
|
* tcp_get_sndbuf() - Get, scale SO_SNDBUF between thresholds (1 to 0.5 usage)
|
|
* @conn: Connection pointer
|
|
*/
|
|
static void tcp_get_sndbuf(struct tcp_tap_conn *conn)
|
|
{
|
|
int s = conn->sock, v;
|
|
socklen_t sl;
|
|
|
|
sl = sizeof(v);
|
|
if (getsockopt(s, SOL_SOCKET, SO_SNDBUF, &v, &sl)) {
|
|
conn->snd_buf = WINDOW_DEFAULT;
|
|
return;
|
|
}
|
|
|
|
if (v >= SNDBUF_BIG)
|
|
v /= 2;
|
|
else if (v > SNDBUF_SMALL)
|
|
v -= v * (v - SNDBUF_SMALL) / (SNDBUF_BIG - SNDBUF_SMALL) / 2;
|
|
|
|
conn->snd_buf = v;
|
|
}
|
|
|
|
/**
|
|
* tcp_sock_set_bufsize() - Set SO_RCVBUF and SO_SNDBUF to maximum values
|
|
* @s: Socket, can be -1 to avoid check in the caller
|
|
*/
|
|
static void tcp_sock_set_bufsize(struct ctx *c, int s)
|
|
{
|
|
int v = INT_MAX / 2; /* Kernel clamps and rounds, no need to check */
|
|
|
|
if (s == -1)
|
|
return;
|
|
|
|
if (!c->low_rmem)
|
|
setsockopt(s, SOL_SOCKET, SO_RCVBUF, &v, sizeof(v));
|
|
|
|
if (!c->low_wmem)
|
|
setsockopt(s, SOL_SOCKET, SO_SNDBUF, &v, sizeof(v));
|
|
}
|
|
|
|
/**
|
|
* tcp_update_check_ip4() - Update IPv4 with variable parts from stored one
|
|
* @buf: L2 packet buffer with final IPv4 header
|
|
*/
|
|
static void tcp_update_check_ip4(struct tcp4_l2_buf_t *buf)
|
|
{
|
|
uint32_t sum = buf->psum;
|
|
|
|
sum += buf->iph.tot_len;
|
|
sum += (buf->iph.saddr >> 16) & 0xffff;
|
|
sum += buf->iph.saddr & 0xffff;
|
|
|
|
buf->iph.check = (uint16_t)~csum_fold(sum);
|
|
}
|
|
|
|
/**
|
|
* tcp_update_check_tcp4() - Update TCP checksum from stored one
|
|
* @buf: L2 packet buffer with final IPv4 header
|
|
*/
|
|
static void tcp_update_check_tcp4(struct tcp4_l2_buf_t *buf)
|
|
{
|
|
uint16_t tlen = ntohs(buf->iph.tot_len) - 20;
|
|
uint32_t sum = buf->tsum;
|
|
|
|
sum += (buf->iph.saddr >> 16) & 0xffff;
|
|
sum += buf->iph.saddr & 0xffff;
|
|
sum += htons(ntohs(buf->iph.tot_len) - 20);
|
|
|
|
buf->th.check = 0;
|
|
buf->th.check = csum(&buf->th, tlen, sum);
|
|
}
|
|
|
|
/**
|
|
* tcp_update_check_tcp6() - Calculate TCP checksum for IPv6
|
|
* @buf: L2 packet buffer with final IPv6 header
|
|
*/
|
|
static void tcp_update_check_tcp6(struct tcp6_l2_buf_t *buf)
|
|
{
|
|
int len = ntohs(buf->ip6h.payload_len) + sizeof(struct ipv6hdr);
|
|
|
|
buf->ip6h.hop_limit = IPPROTO_TCP;
|
|
buf->ip6h.version = 0;
|
|
buf->ip6h.nexthdr = 0;
|
|
|
|
buf->th.check = 0;
|
|
buf->th.check = csum(&buf->ip6h, len, 0);
|
|
|
|
buf->ip6h.hop_limit = 255;
|
|
buf->ip6h.version = 6;
|
|
buf->ip6h.nexthdr = IPPROTO_TCP;
|
|
}
|
|
|
|
/**
|
|
* tcp_update_l2_buf() - Update L2 buffers with Ethernet and IPv4 addresses
|
|
* @eth_d: Ethernet destination address, NULL if unchanged
|
|
* @eth_s: Ethernet source address, NULL if unchanged
|
|
* @ip_da: Pointer to IPv4 destination address, NULL if unchanged
|
|
*/
|
|
void tcp_update_l2_buf(unsigned char *eth_d, unsigned char *eth_s,
|
|
uint32_t *ip_da)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < TCP_TAP_FRAMES; i++) {
|
|
struct tcp4_l2_flags_buf_t *b4f = &tcp4_l2_flags_buf[i];
|
|
struct tcp6_l2_flags_buf_t *b6f = &tcp6_l2_flags_buf[i];
|
|
struct tcp4_l2_buf_t *b4 = &tcp4_l2_buf[i];
|
|
struct tcp6_l2_buf_t *b6 = &tcp6_l2_buf[i];
|
|
|
|
if (eth_d) {
|
|
memcpy(b4->eh.h_dest, eth_d, ETH_ALEN);
|
|
memcpy(b6->eh.h_dest, eth_d, ETH_ALEN);
|
|
|
|
memcpy(b4f->eh.h_dest, eth_d, ETH_ALEN);
|
|
memcpy(b6f->eh.h_dest, eth_d, ETH_ALEN);
|
|
}
|
|
|
|
if (eth_s) {
|
|
memcpy(b4->eh.h_source, eth_s, ETH_ALEN);
|
|
memcpy(b6->eh.h_source, eth_s, ETH_ALEN);
|
|
|
|
memcpy(b4f->eh.h_source, eth_s, ETH_ALEN);
|
|
memcpy(b6f->eh.h_source, eth_s, ETH_ALEN);
|
|
}
|
|
|
|
if (ip_da) {
|
|
b4f->iph.daddr = b4->iph.daddr = *ip_da;
|
|
if (!i) {
|
|
b4f->iph.saddr = b4->iph.saddr = 0;
|
|
b4f->iph.tot_len = b4->iph.tot_len = 0;
|
|
b4f->iph.check = b4->iph.check = 0;
|
|
b4f->psum = b4->psum = sum_16b(&b4->iph, 20);
|
|
|
|
b4->tsum = ((*ip_da >> 16) & 0xffff) +
|
|
(*ip_da & 0xffff) +
|
|
htons(IPPROTO_TCP);
|
|
b4f->tsum = b4->tsum;
|
|
} else {
|
|
b4f->psum = b4->psum = tcp4_l2_buf[0].psum;
|
|
b4f->tsum = b4->tsum = tcp4_l2_buf[0].tsum;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* tcp_sock4_iov_init() - Initialise scatter-gather L2 buffers for IPv4 sockets
|
|
*/
|
|
static void tcp_sock4_iov_init(void)
|
|
{
|
|
struct iovec *iov;
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(tcp4_l2_buf); i++) {
|
|
tcp4_l2_buf[i] = (struct tcp4_l2_buf_t) { 0, 0,
|
|
#ifdef __AVX2__
|
|
{ 0 },
|
|
#endif
|
|
0, L2_BUF_ETH_IP4_INIT, L2_BUF_IP4_INIT(IPPROTO_TCP),
|
|
{ .doff = sizeof(struct tcphdr) / 4, .ack = 1 }, { 0 },
|
|
};
|
|
}
|
|
|
|
for (i = 0; i < ARRAY_SIZE(tcp4_l2_flags_buf); i++) {
|
|
tcp4_l2_flags_buf[i] = (struct tcp4_l2_flags_buf_t) { 0, 0,
|
|
#ifdef __AVX2__
|
|
{ 0 },
|
|
#endif
|
|
0, L2_BUF_ETH_IP4_INIT, L2_BUF_IP4_INIT(IPPROTO_TCP),
|
|
{ 0 }, { 0 },
|
|
};
|
|
}
|
|
|
|
tcp4_l2_iov_sock[0].iov_base = tcp_buf_discard;
|
|
for (i = 0, iov = tcp4_l2_iov_sock + 1; i < TCP_TAP_FRAMES;
|
|
i++, iov++) {
|
|
iov->iov_base = &tcp4_l2_buf[i].data;
|
|
iov->iov_len = MSS_DEFAULT;
|
|
}
|
|
|
|
tcp4_l2_mh_sock.msg_iov = tcp4_l2_iov_sock;
|
|
|
|
for (i = 0, iov = tcp4_l2_iov_tap; i < TCP_TAP_FRAMES; i++, iov++) {
|
|
iov->iov_base = &tcp4_l2_buf[i].vnet_len;
|
|
iov->iov_len = MSS_DEFAULT;
|
|
}
|
|
|
|
for (i = 0, iov = tcp4_l2_flags_iov_tap; i < TCP_TAP_FRAMES; i++, iov++)
|
|
iov->iov_base = &tcp4_l2_flags_buf[i].vnet_len;
|
|
}
|
|
|
|
/**
|
|
* tcp_sock6_iov_init() - Initialise scatter-gather L2 buffers for IPv6 sockets
|
|
*/
|
|
static void tcp_sock6_iov_init(void)
|
|
{
|
|
struct iovec *iov;
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(tcp6_l2_buf); i++) {
|
|
tcp6_l2_buf[i] = (struct tcp6_l2_buf_t) {
|
|
{ 0 },
|
|
0, L2_BUF_ETH_IP6_INIT, L2_BUF_IP6_INIT(IPPROTO_TCP),
|
|
{ .doff = sizeof(struct tcphdr) / 4, .ack = 1 }, { 0 },
|
|
};
|
|
}
|
|
|
|
for (i = 0; i < ARRAY_SIZE(tcp6_l2_flags_buf); i++) {
|
|
tcp6_l2_flags_buf[i] = (struct tcp6_l2_flags_buf_t) {
|
|
{ 0 },
|
|
0, L2_BUF_ETH_IP6_INIT, L2_BUF_IP6_INIT(IPPROTO_TCP),
|
|
{ 0 }, { 0 },
|
|
};
|
|
}
|
|
|
|
tcp6_l2_iov_sock[0].iov_base = tcp_buf_discard;
|
|
for (i = 0, iov = tcp6_l2_iov_sock + 1; i < TCP_TAP_FRAMES;
|
|
i++, iov++) {
|
|
iov->iov_base = &tcp6_l2_buf[i].data;
|
|
iov->iov_len = MSS_DEFAULT;
|
|
}
|
|
|
|
tcp6_l2_mh_sock.msg_iov = tcp6_l2_iov_sock;
|
|
|
|
for (i = 0, iov = tcp6_l2_iov_tap; i < TCP_TAP_FRAMES; i++, iov++) {
|
|
iov->iov_base = &tcp6_l2_buf[i].vnet_len;
|
|
iov->iov_len = MSS_DEFAULT;
|
|
}
|
|
|
|
for (i = 0, iov = tcp6_l2_flags_iov_tap; i < TCP_TAP_FRAMES; i++, iov++)
|
|
iov->iov_base = &tcp6_l2_flags_buf[i].vnet_len;
|
|
}
|
|
|
|
/**
|
|
* tcp_opt_get() - Get option, and value if any, from TCP header
|
|
* @th: Pointer to TCP header
|
|
* @len: Length of buffer, including TCP header
|
|
* @__type: Option type to look for
|
|
* @__optlen: Optional, filled with option length if passed
|
|
* @__value: Optional, set to start of option value if passed
|
|
*
|
|
* Return: Option value, meaningful for up to 4 bytes, -1 if not found
|
|
*/
|
|
static int tcp_opt_get(struct tcphdr *th, size_t len, uint8_t __type,
|
|
uint8_t *__optlen, char **__value)
|
|
{
|
|
uint8_t type, optlen;
|
|
char *p;
|
|
|
|
if (len > th->doff * 4)
|
|
len = th->doff * 4;
|
|
|
|
len -= sizeof(*th);
|
|
p = (char *)(th + 1);
|
|
|
|
for (; len >= 2; p += optlen, len -= optlen) {
|
|
switch (*p) {
|
|
case OPT_EOL:
|
|
return -1;
|
|
case OPT_NOP:
|
|
optlen = 1;
|
|
break;
|
|
default:
|
|
type = *(p++);
|
|
optlen = *(p++) - 2;
|
|
len -= 2;
|
|
|
|
if (type != __type)
|
|
break;
|
|
|
|
if (__optlen)
|
|
*__optlen = optlen;
|
|
if (__value)
|
|
*__value = p;
|
|
|
|
switch (optlen) {
|
|
case 0:
|
|
return 0;
|
|
case 1:
|
|
return *p;
|
|
case 2:
|
|
return ntohs(*(uint16_t *)p);
|
|
default:
|
|
return ntohl(*(uint32_t *)p);
|
|
}
|
|
}
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* tcp_hash_match() - Check if a connection entry matches address and ports
|
|
* @conn: Connection entry to match against
|
|
* @af: Address family, AF_INET or AF_INET6
|
|
* @addr: Remote address, pointer to sin_addr or sin6_addr
|
|
* @tap_port: tap-facing port
|
|
* @sock_port: Socket-facing port
|
|
*
|
|
* Return: 1 on match, 0 otherwise
|
|
*/
|
|
static int tcp_hash_match(struct tcp_tap_conn *conn, int af, void *addr,
|
|
in_port_t tap_port, in_port_t sock_port)
|
|
{
|
|
if (af == AF_INET && CONN_V4(conn) &&
|
|
!memcmp(&conn->a.a4.a, addr, sizeof(conn->a.a4.a)) &&
|
|
conn->tap_port == tap_port && conn->sock_port == sock_port)
|
|
return 1;
|
|
|
|
if (af == AF_INET6 &&
|
|
!memcmp(&conn->a.a6, addr, sizeof(conn->a.a6)) &&
|
|
conn->tap_port == tap_port && conn->sock_port == sock_port)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tcp_hash() - Calculate hash value for connection given address and ports
|
|
* @c: Execution context
|
|
* @af: Address family, AF_INET or AF_INET6
|
|
* @addr: Remote address, pointer to sin_addr or sin6_addr
|
|
* @tap_port: tap-facing port
|
|
* @sock_port: Socket-facing port
|
|
*
|
|
* Return: hash value, already modulo size of the hash table
|
|
*/
|
|
static unsigned int tcp_hash(struct ctx *c, int af, void *addr,
|
|
in_port_t tap_port, in_port_t sock_port)
|
|
{
|
|
uint64_t b = 0;
|
|
|
|
if (af == AF_INET) {
|
|
struct {
|
|
struct in_addr addr;
|
|
in_port_t tap_port;
|
|
in_port_t sock_port;
|
|
} __attribute__((__packed__)) in = {
|
|
.addr = *(struct in_addr *)addr,
|
|
.tap_port = tap_port,
|
|
.sock_port = sock_port,
|
|
};
|
|
|
|
b = siphash_8b((uint8_t *)&in, c->tcp.hash_secret);
|
|
} else if (af == AF_INET6) {
|
|
struct {
|
|
struct in6_addr addr;
|
|
in_port_t tap_port;
|
|
in_port_t sock_port;
|
|
} __attribute__((__packed__)) in = {
|
|
.addr = *(struct in6_addr *)addr,
|
|
.tap_port = tap_port,
|
|
.sock_port = sock_port,
|
|
};
|
|
|
|
b = siphash_20b((uint8_t *)&in, c->tcp.hash_secret);
|
|
}
|
|
|
|
return (unsigned int)(b % TCP_HASH_TABLE_SIZE);
|
|
}
|
|
|
|
/**
|
|
* tcp_hash_insert() - Insert connection into hash table, chain link
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
* @af: Address family, AF_INET or AF_INET6
|
|
* @addr: Remote address, pointer to sin_addr or sin6_addr
|
|
*/
|
|
static void tcp_hash_insert(struct ctx *c, struct tcp_tap_conn *conn,
|
|
int af, void *addr)
|
|
{
|
|
int b;
|
|
|
|
b = tcp_hash(c, af, addr, conn->tap_port, conn->sock_port);
|
|
conn->next = tt_hash[b];
|
|
tt_hash[b] = conn;
|
|
conn->hash_bucket = b;
|
|
|
|
debug("TCP: hash table insert: index %i, sock %i, bucket: %i, next: %p",
|
|
conn - tt, conn->sock, b, conn->next);
|
|
}
|
|
|
|
/**
|
|
* tcp_hash_remove() - Drop connection from hash table, chain unlink
|
|
* @conn: Connection pointer
|
|
*/
|
|
static void tcp_hash_remove(struct tcp_tap_conn *conn)
|
|
{
|
|
struct tcp_tap_conn *entry, *prev = NULL;
|
|
int b = conn->hash_bucket;
|
|
|
|
for (entry = tt_hash[b]; entry; prev = entry, entry = entry->next) {
|
|
if (entry == conn) {
|
|
if (prev)
|
|
prev->next = conn->next;
|
|
else
|
|
tt_hash[b] = conn->next;
|
|
break;
|
|
}
|
|
}
|
|
|
|
debug("TCP: hash table remove: index %i, sock %i, bucket: %i, new: %p",
|
|
conn - tt, conn->sock, b, prev ? prev->next : tt_hash[b]);
|
|
}
|
|
|
|
/**
|
|
* tcp_hash_update() - Update pointer for given connection
|
|
* @old: Old connection pointer
|
|
* @new: New connection pointer
|
|
*/
|
|
static void tcp_hash_update(struct tcp_tap_conn *old, struct tcp_tap_conn *new)
|
|
{
|
|
struct tcp_tap_conn *entry, *prev = NULL;
|
|
int b = old->hash_bucket;
|
|
|
|
for (entry = tt_hash[b]; entry; prev = entry, entry = entry->next) {
|
|
if (entry == old) {
|
|
if (prev)
|
|
prev->next = new;
|
|
else
|
|
tt_hash[b] = new;
|
|
break;
|
|
}
|
|
}
|
|
|
|
debug("TCP: hash table update: old index %i, new index %i, sock %i, "
|
|
"bucket: %i, old: %p, new: %p",
|
|
old - tt, new - tt, new->sock, b, old, new);
|
|
}
|
|
|
|
/**
|
|
* tcp_hash_lookup() - Look up connection given remote address and ports
|
|
* @c: Execution context
|
|
* @af: Address family, AF_INET or AF_INET6
|
|
* @addr: Remote address, pointer to sin_addr or sin6_addr
|
|
* @tap_port: tap-facing port
|
|
* @sock_port: Socket-facing port
|
|
*
|
|
* Return: connection pointer, if found, -ENOENT otherwise
|
|
*/
|
|
static struct tcp_tap_conn *tcp_hash_lookup(struct ctx *c, int af, void *addr,
|
|
in_port_t tap_port,
|
|
in_port_t sock_port)
|
|
{
|
|
int b = tcp_hash(c, af, addr, tap_port, sock_port);
|
|
struct tcp_tap_conn *conn;
|
|
|
|
for (conn = tt_hash[b]; conn; conn = conn->next) {
|
|
if (tcp_hash_match(conn, af, addr, tap_port, sock_port))
|
|
return conn;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* tcp_tap_epoll_mask() - Set new epoll event mask given a connection
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
* @events: New epoll event bitmap
|
|
*/
|
|
static void tcp_tap_epoll_mask(struct ctx *c, struct tcp_tap_conn *conn,
|
|
uint32_t events)
|
|
{
|
|
union epoll_ref ref = { .proto = IPPROTO_TCP, .s = conn->sock,
|
|
.tcp.index = conn - tt,
|
|
.tcp.v6 = CONN_V6(conn) };
|
|
struct epoll_event ev = { .data.u64 = ref.u64, .events = events };
|
|
|
|
if (conn->events == events)
|
|
return;
|
|
|
|
conn->events = events;
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_MOD, conn->sock, &ev);
|
|
}
|
|
|
|
/**
|
|
* tcp_table_tap_compact() - Perform compaction on tap connection table
|
|
* @c: Execution context
|
|
* @hole: Pointer to recently closed connection
|
|
*/
|
|
static void tcp_table_tap_compact(struct ctx *c, struct tcp_tap_conn *hole)
|
|
{
|
|
struct tcp_tap_conn *from, *to;
|
|
uint32_t events;
|
|
|
|
if ((hole - tt) == --c->tcp.tap_conn_count) {
|
|
debug("TCP: hash table compaction: index %i (%p) was max index",
|
|
hole - tt, hole);
|
|
return;
|
|
}
|
|
|
|
from = &tt[c->tcp.tap_conn_count];
|
|
memcpy(hole, from, sizeof(*hole));
|
|
from->state = CLOSED;
|
|
|
|
to = hole;
|
|
tcp_hash_update(from, to);
|
|
|
|
events = hole->events;
|
|
hole->events = UINT_MAX;
|
|
tcp_tap_epoll_mask(c, hole, events);
|
|
|
|
debug("TCP: hash table compaction: old index %i, new index %i, "
|
|
"sock %i, from: %p, to: %p",
|
|
from - tt, to - tt, from->sock, from, to);
|
|
}
|
|
|
|
/**
|
|
* tcp_tap_destroy() - Close tap connection, drop from hash table and epoll
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
*/
|
|
static void tcp_tap_destroy(struct ctx *c, struct tcp_tap_conn *conn)
|
|
{
|
|
if (conn->state == CLOSED)
|
|
return;
|
|
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_DEL, conn->sock, NULL);
|
|
tcp_tap_state(conn, CLOSED);
|
|
close(conn->sock);
|
|
|
|
/* Removal from hash table and connection table compaction deferred to
|
|
* timer.
|
|
*/
|
|
}
|
|
|
|
static void tcp_rst(struct ctx *c, struct tcp_tap_conn *conn);
|
|
|
|
/**
|
|
* tcp_l2_flags_buf_flush() - Send out buffers for segments with no data (flags)
|
|
* @c: Execution context
|
|
*/
|
|
static void tcp_l2_flags_buf_flush(struct ctx *c)
|
|
{
|
|
struct msghdr mh = { 0 };
|
|
size_t i;
|
|
|
|
mh.msg_iov = tcp6_l2_flags_iov_tap;
|
|
if ((mh.msg_iovlen = tcp6_l2_flags_buf_used)) {
|
|
if (c->mode == MODE_PASST) {
|
|
sendmsg(c->fd_tap, &mh, MSG_NOSIGNAL | MSG_DONTWAIT);
|
|
} else {
|
|
for (i = 0; i < mh.msg_iovlen; i++) {
|
|
struct iovec *iov = &mh.msg_iov[i];
|
|
|
|
write(c->fd_tap, (char *)iov->iov_base + 4,
|
|
iov->iov_len - 4);
|
|
}
|
|
}
|
|
tcp6_l2_flags_buf_used = 0;
|
|
pcapm(&mh);
|
|
}
|
|
|
|
mh.msg_iov = tcp4_l2_flags_iov_tap;
|
|
if ((mh.msg_iovlen = tcp4_l2_flags_buf_used)) {
|
|
if (c->mode == MODE_PASST) {
|
|
sendmsg(c->fd_tap, &mh, MSG_NOSIGNAL | MSG_DONTWAIT);
|
|
} else {
|
|
for (i = 0; i < mh.msg_iovlen; i++) {
|
|
struct iovec *iov = &mh.msg_iov[i];
|
|
|
|
write(c->fd_tap, (char *)iov->iov_base + 4,
|
|
iov->iov_len - 4);
|
|
}
|
|
}
|
|
tcp4_l2_flags_buf_used = 0;
|
|
pcapm(&mh);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* tcp_defer_handler() - Handler for TCP deferred tasks
|
|
* @c: Execution context
|
|
*/
|
|
void tcp_defer_handler(struct ctx *c)
|
|
{
|
|
tcp_l2_flags_buf_flush(c);
|
|
}
|
|
|
|
/**
|
|
* tcp_l2_buf_fill_headers() - Fill 802.3, IP, TCP headers in pre-cooked buffers
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
* @p: Pointer to any type of TCP pre-cooked buffer
|
|
* @plen: Payload length (including TCP header options)
|
|
* @check: Checksum, if already known
|
|
* @seq: Sequence number for this segment
|
|
*
|
|
* Return: 802.3 length, host order.
|
|
*/
|
|
static size_t tcp_l2_buf_fill_headers(struct ctx *c, struct tcp_tap_conn *conn,
|
|
void *p, size_t plen,
|
|
uint16_t *check, uint32_t seq)
|
|
{
|
|
size_t ip_len, eth_len;
|
|
|
|
#define SET_TCP_HEADER_COMMON_V4_V6(b, conn, seq) \
|
|
do { \
|
|
b->th.source = htons(conn->sock_port); \
|
|
b->th.dest = htons(conn->tap_port); \
|
|
b->th.seq = htonl(seq); \
|
|
b->th.ack_seq = htonl(conn->seq_ack_to_tap); \
|
|
\
|
|
/* First value sent by receiver is not scaled */ \
|
|
if (b->th.syn) { \
|
|
b->th.window = htons(MIN(conn->wnd_to_tap, \
|
|
USHRT_MAX)); \
|
|
} else { \
|
|
b->th.window = htons(MIN(conn->wnd_to_tap >> \
|
|
conn->ws, \
|
|
USHRT_MAX)); \
|
|
} \
|
|
} while (0)
|
|
|
|
if (CONN_V6(conn)) {
|
|
struct tcp6_l2_buf_t *b = (struct tcp6_l2_buf_t *)p;
|
|
uint32_t flow = conn->seq_init_to_tap;
|
|
|
|
ip_len = plen + sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
|
|
|
|
b->ip6h.payload_len = htons(plen + sizeof(struct tcphdr));
|
|
b->ip6h.saddr = conn->a.a6;
|
|
if (IN6_IS_ADDR_LINKLOCAL(&b->ip6h.saddr))
|
|
b->ip6h.daddr = c->addr6_ll_seen;
|
|
else
|
|
b->ip6h.daddr = c->addr6_seen;
|
|
|
|
memset(b->ip6h.flow_lbl, 0, 3);
|
|
|
|
SET_TCP_HEADER_COMMON_V4_V6(b, conn, seq);
|
|
|
|
tcp_update_check_tcp6(b);
|
|
|
|
b->ip6h.flow_lbl[0] = (flow >> 16) & 0xf;
|
|
b->ip6h.flow_lbl[1] = (flow >> 8) & 0xff;
|
|
b->ip6h.flow_lbl[2] = (flow >> 0) & 0xff;
|
|
|
|
eth_len = ip_len + sizeof(struct ethhdr);
|
|
if (c->mode == MODE_PASST)
|
|
b->vnet_len = htonl(eth_len);
|
|
} else {
|
|
struct tcp4_l2_buf_t *b = (struct tcp4_l2_buf_t *)p;
|
|
|
|
ip_len = plen + sizeof(struct iphdr) + sizeof(struct tcphdr);
|
|
b->iph.tot_len = htons(ip_len);
|
|
b->iph.saddr = conn->a.a4.a.s_addr;
|
|
b->iph.daddr = c->addr4_seen;
|
|
|
|
if (check)
|
|
b->iph.check = *check;
|
|
else
|
|
tcp_update_check_ip4(b);
|
|
|
|
SET_TCP_HEADER_COMMON_V4_V6(b, conn, seq);
|
|
|
|
tcp_update_check_tcp4(b);
|
|
|
|
eth_len = ip_len + sizeof(struct ethhdr);
|
|
if (c->mode == MODE_PASST)
|
|
b->vnet_len = htonl(eth_len);
|
|
}
|
|
|
|
#undef SET_TCP_HEADER_COMMON_V4_V6
|
|
|
|
return eth_len;
|
|
}
|
|
|
|
/**
|
|
* tcp_update_seqack_wnd() - Update ACK sequence and window to guest/tap
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
* @flags: TCP header flags we are about to send, if any
|
|
* @info: tcp_info from kernel, can be NULL if not pre-fetched
|
|
*
|
|
* Return: 1 if sequence or window were updated, 0 otherwise
|
|
*/
|
|
static int tcp_update_seqack_wnd(struct ctx *c, struct tcp_tap_conn *conn,
|
|
int flags, struct tcp_info *info)
|
|
{
|
|
uint32_t prev_ack_to_tap = conn->seq_ack_to_tap;
|
|
uint32_t prev_wnd_to_tap = conn->wnd_to_tap;
|
|
socklen_t sl = sizeof(*info);
|
|
struct tcp_info __info;
|
|
int s = conn->sock;
|
|
|
|
if (conn->state > ESTABLISHED || (flags & (DUP_ACK | FORCE_ACK)) ||
|
|
conn->local || tcp_rtt_dst_low(conn) ||
|
|
conn->snd_buf < SNDBUF_SMALL) {
|
|
conn->seq_ack_to_tap = conn->seq_from_tap;
|
|
} else if (conn->seq_ack_to_tap != conn->seq_from_tap) {
|
|
if (!info) {
|
|
info = &__info;
|
|
if (getsockopt(s, SOL_TCP, TCP_INFO, info, &sl))
|
|
return 0;
|
|
}
|
|
|
|
conn->seq_ack_to_tap = info->tcpi_bytes_acked +
|
|
conn->seq_init_from_tap;
|
|
|
|
if (SEQ_LT(conn->seq_ack_to_tap, prev_ack_to_tap))
|
|
conn->seq_ack_to_tap = prev_ack_to_tap;
|
|
}
|
|
|
|
if (!c->tcp.kernel_snd_wnd) {
|
|
tcp_get_sndbuf(conn);
|
|
conn->wnd_to_tap = MIN(conn->snd_buf, MAX_WINDOW);
|
|
return 0;
|
|
}
|
|
|
|
if (!info) {
|
|
if (conn->wnd_to_tap > WINDOW_DEFAULT)
|
|
return 0;
|
|
|
|
info = &__info;
|
|
if (getsockopt(s, SOL_TCP, TCP_INFO, info, &sl))
|
|
return 0;
|
|
}
|
|
|
|
if (conn->local || tcp_rtt_dst_low(conn)) {
|
|
conn->wnd_to_tap = info->tcpi_snd_wnd;
|
|
} else {
|
|
tcp_get_sndbuf(conn);
|
|
conn->wnd_to_tap = MIN(info->tcpi_snd_wnd, conn->snd_buf);
|
|
}
|
|
|
|
conn->wnd_to_tap = MIN(conn->wnd_to_tap, MAX_WINDOW);
|
|
|
|
return conn->wnd_to_tap != prev_wnd_to_tap ||
|
|
conn->seq_ack_to_tap != prev_ack_to_tap;
|
|
}
|
|
|
|
/**
|
|
* tcp_send_to_tap() - Send segment to tap, with options and values from socket
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
* @flags: TCP flags to set
|
|
* @now: Current timestamp, can be NULL
|
|
*
|
|
* Return: negative error code on connection reset, 0 otherwise
|
|
*/
|
|
static int tcp_send_to_tap(struct ctx *c, struct tcp_tap_conn *conn, int flags,
|
|
struct timespec *now)
|
|
{
|
|
uint32_t prev_ack_to_tap = conn->seq_ack_to_tap;
|
|
uint32_t prev_wnd_to_tap = conn->wnd_to_tap;
|
|
struct tcp4_l2_flags_buf_t *b4 = NULL;
|
|
struct tcp6_l2_flags_buf_t *b6 = NULL;
|
|
struct tcp_info info = { 0 };
|
|
socklen_t sl = sizeof(info);
|
|
size_t optlen = 0, eth_len;
|
|
int s = conn->sock;
|
|
struct iovec *iov;
|
|
struct tcphdr *th;
|
|
char *data;
|
|
void *p;
|
|
|
|
if (SEQ_GE(conn->seq_ack_to_tap, conn->seq_from_tap) &&
|
|
!flags && conn->wnd_to_tap)
|
|
return 0;
|
|
|
|
if (getsockopt(s, SOL_TCP, TCP_INFO, &info, &sl)) {
|
|
tcp_rst(c, conn);
|
|
return -ECONNRESET;
|
|
}
|
|
|
|
if (!conn->local)
|
|
tcp_rtt_dst_check(conn, &info);
|
|
|
|
if (!tcp_update_seqack_wnd(c, conn, flags, &info) && !flags)
|
|
return 0;
|
|
|
|
if (CONN_V4(conn)) {
|
|
iov = tcp4_l2_flags_iov_tap + tcp4_l2_flags_buf_used;
|
|
p = b4 = tcp4_l2_flags_buf + tcp4_l2_flags_buf_used++;
|
|
th = &b4->th;
|
|
} else {
|
|
iov = tcp6_l2_flags_iov_tap + tcp6_l2_flags_buf_used;
|
|
p = b6 = tcp6_l2_flags_buf + tcp6_l2_flags_buf_used++;
|
|
th = &b6->th;
|
|
}
|
|
|
|
data = (char *)(th + 1);
|
|
|
|
if (flags & SYN) {
|
|
uint16_t mss;
|
|
|
|
/* Options: MSS, NOP and window scale (8 bytes) */
|
|
optlen = OPT_MSS_LEN + 1 + OPT_WS_LEN;
|
|
|
|
*data++ = OPT_MSS;
|
|
*data++ = OPT_MSS_LEN;
|
|
|
|
if (c->mtu == -1) {
|
|
mss = info.tcpi_snd_mss;
|
|
} else {
|
|
mss = c->mtu - sizeof(sizeof *th);
|
|
if (CONN_V4(conn))
|
|
mss -= sizeof(struct iphdr);
|
|
else
|
|
mss -= sizeof(struct ipv6hdr);
|
|
|
|
if (c->low_wmem &&
|
|
!conn->local && !tcp_rtt_dst_low(conn))
|
|
mss = MIN(mss, PAGE_SIZE);
|
|
else
|
|
mss = ROUND_DOWN(mss, PAGE_SIZE);
|
|
}
|
|
*(uint16_t *)data = htons(mss);
|
|
|
|
data += OPT_MSS_LEN - 2;
|
|
th->doff += OPT_MSS_LEN / 4;
|
|
|
|
if (!c->tcp.kernel_snd_wnd && info.tcpi_snd_wnd)
|
|
c->tcp.kernel_snd_wnd = 1;
|
|
|
|
conn->ws = MIN(MAX_WS, info.tcpi_snd_wscale);
|
|
|
|
*data++ = OPT_NOP;
|
|
*data++ = OPT_WS;
|
|
*data++ = OPT_WS_LEN;
|
|
*data++ = conn->ws;
|
|
|
|
th->ack = !!(flags & ACK);
|
|
|
|
conn->wnd_to_tap = WINDOW_DEFAULT;
|
|
} else {
|
|
th->ack = !!(flags & (ACK | FORCE_ACK | DUP_ACK)) ||
|
|
conn->seq_ack_to_tap != prev_ack_to_tap ||
|
|
!prev_wnd_to_tap;
|
|
}
|
|
|
|
th->doff = (sizeof(*th) + optlen) / 4;
|
|
|
|
th->rst = !!(flags & RST);
|
|
th->syn = !!(flags & SYN);
|
|
th->fin = !!(flags & FIN);
|
|
|
|
eth_len = tcp_l2_buf_fill_headers(c, conn, p, optlen,
|
|
NULL, conn->seq_to_tap);
|
|
iov->iov_len = eth_len + sizeof(uint32_t);
|
|
|
|
if (th->ack && now)
|
|
conn->ts_ack_to_tap = *now;
|
|
|
|
if (th->fin && now)
|
|
conn->tap_data_noack = *now;
|
|
|
|
/* RFC 793, 3.1: "[...] and the first data octet is ISN+1." */
|
|
if (th->fin || th->syn)
|
|
conn->seq_to_tap++;
|
|
|
|
if (CONN_V4(conn)) {
|
|
if (flags & DUP_ACK) {
|
|
memcpy(b4 + 1, b4, sizeof(*b4));
|
|
(iov + 1)->iov_len = iov->iov_len;
|
|
tcp4_l2_flags_buf_used++;
|
|
}
|
|
|
|
if (tcp4_l2_flags_buf_used > ARRAY_SIZE(tcp4_l2_flags_buf) - 2)
|
|
tcp_l2_flags_buf_flush(c);
|
|
} else {
|
|
if (flags & DUP_ACK) {
|
|
memcpy(b6 + 1, b6, sizeof(*b6));
|
|
(iov + 1)->iov_len = iov->iov_len;
|
|
tcp6_l2_flags_buf_used++;
|
|
}
|
|
if (tcp6_l2_flags_buf_used > ARRAY_SIZE(tcp6_l2_flags_buf) - 2)
|
|
tcp_l2_flags_buf_flush(c);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tcp_rst() - Reset a tap connection: send RST segment to tap, close socket
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
*/
|
|
static void tcp_rst(struct ctx *c, struct tcp_tap_conn *conn)
|
|
{
|
|
if (conn->state == CLOSED)
|
|
return;
|
|
|
|
tcp_send_to_tap(c, conn, RST, NULL);
|
|
tcp_tap_destroy(c, conn);
|
|
}
|
|
|
|
/**
|
|
* tcp_clamp_window() - Set window and scaling from option, clamp on socket
|
|
* @conn: Connection pointer
|
|
* @th: TCP header, from tap, can be NULL if window is passed
|
|
* @len: Buffer length, at L4, can be 0 if no header is passed
|
|
* @window: Window value, host order, unscaled, if no header is passed
|
|
* @init: Set if this is the very first segment from tap
|
|
*/
|
|
static void tcp_clamp_window(struct tcp_tap_conn *conn, struct tcphdr *th,
|
|
int len, unsigned int window, int init)
|
|
{
|
|
if (init) {
|
|
int ws = tcp_opt_get(th, len, OPT_WS, NULL, NULL);
|
|
|
|
conn->ws_tap = ws;
|
|
|
|
/* RFC 7323, 2.2: first value is not scaled. Also, don't clamp
|
|
* yet, to avoid getting a zero scale just because we set a
|
|
* small window now.
|
|
*/
|
|
conn->wnd_from_tap = ntohs(th->window);
|
|
conn->window_clamped = 0;
|
|
} else {
|
|
if (th)
|
|
window = ntohs(th->window) << conn->ws_tap;
|
|
else
|
|
window <<= conn->ws_tap;
|
|
|
|
window = MIN(MAX_WINDOW, window);
|
|
|
|
if (conn->window_clamped) {
|
|
if (conn->wnd_from_tap == window)
|
|
return;
|
|
|
|
/* Discard +/- 1% updates to spare some syscalls. */
|
|
if ((window > conn->wnd_from_tap &&
|
|
window * 99 / 100 < conn->wnd_from_tap) ||
|
|
(window < conn->wnd_from_tap &&
|
|
window * 101 / 100 > conn->wnd_from_tap)) {
|
|
conn->wnd_from_tap = window;
|
|
return;
|
|
}
|
|
}
|
|
|
|
conn->wnd_from_tap = window;
|
|
if (window < 256)
|
|
window = 256;
|
|
setsockopt(conn->sock, SOL_TCP, TCP_WINDOW_CLAMP,
|
|
&window, sizeof(window));
|
|
conn->window_clamped = 1;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* tcp_seq_init() - Calculate initial sequence number according to RFC 6528
|
|
* @c: Execution context
|
|
* @af: Address family, AF_INET or AF_INET6
|
|
* @addr: Remote address, pointer to sin_addr or sin6_addr
|
|
* @dstport: Destination port, connection-wise, network order
|
|
* @srcport: Source port, connection-wise, network order
|
|
* @now: Current timestamp
|
|
*
|
|
* Return: initial TCP sequence
|
|
*/
|
|
static uint32_t tcp_seq_init(struct ctx *c, int af, void *addr,
|
|
in_port_t dstport, in_port_t srcport,
|
|
struct timespec *now)
|
|
{
|
|
uint32_t ns, seq = 0;
|
|
|
|
if (af == AF_INET) {
|
|
struct {
|
|
struct in_addr src;
|
|
in_port_t srcport;
|
|
struct in_addr dst;
|
|
in_port_t dstport;
|
|
} __attribute__((__packed__)) in = {
|
|
.src = *(struct in_addr *)addr,
|
|
.srcport = srcport,
|
|
.dst = { c->addr4 },
|
|
.dstport = dstport,
|
|
};
|
|
|
|
seq = siphash_12b((uint8_t *)&in, c->tcp.hash_secret);
|
|
} else if (af == AF_INET6) {
|
|
struct {
|
|
struct in6_addr src;
|
|
in_port_t srcport;
|
|
struct in6_addr dst;
|
|
in_port_t dstport;
|
|
} __attribute__((__packed__)) in = {
|
|
.src = *(struct in6_addr *)addr,
|
|
.srcport = srcport,
|
|
.dst = c->addr6,
|
|
.dstport = dstport,
|
|
};
|
|
|
|
seq = siphash_36b((uint8_t *)&in, c->tcp.hash_secret);
|
|
}
|
|
|
|
ns = now->tv_sec * 1E9;
|
|
ns += now->tv_nsec >> 5; /* 32ns ticks, overflows 32 bits every 137s */
|
|
|
|
return seq + ns;
|
|
}
|
|
|
|
/**
|
|
* tcp_conn_from_tap() - Handle connection request (SYN segment) from tap
|
|
* @c: Execution context
|
|
* @af: Address family, AF_INET or AF_INET6
|
|
* @addr: Remote address, pointer to sin_addr or sin6_addr
|
|
* @th: TCP header from tap
|
|
* @len: Packet length at L4
|
|
* @now: Current timestamp
|
|
*/
|
|
static void tcp_conn_from_tap(struct ctx *c, int af, void *addr,
|
|
struct tcphdr *th, size_t len,
|
|
struct timespec *now)
|
|
{
|
|
struct sockaddr_in addr4 = {
|
|
.sin_family = AF_INET,
|
|
.sin_port = th->dest,
|
|
.sin_addr = *(struct in_addr *)addr,
|
|
};
|
|
struct sockaddr_in6 addr6 = {
|
|
.sin6_family = AF_INET6,
|
|
.sin6_port = th->dest,
|
|
.sin6_addr = *(struct in6_addr *)addr,
|
|
};
|
|
union epoll_ref ref = { .proto = IPPROTO_TCP };
|
|
const struct sockaddr *sa;
|
|
struct tcp_tap_conn *conn;
|
|
int i, s, *sock_pool_p;
|
|
struct epoll_event ev;
|
|
socklen_t sl;
|
|
|
|
if (c->tcp.tap_conn_count >= MAX_TAP_CONNS)
|
|
return;
|
|
|
|
for (i = 0; i < TCP_SOCK_POOL_SIZE; i++) {
|
|
if (af == AF_INET6)
|
|
sock_pool_p = &init_sock_pool6[i];
|
|
else
|
|
sock_pool_p = &init_sock_pool4[i];
|
|
if ((ref.s = s = *sock_pool_p) > 0) {
|
|
*sock_pool_p = -1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (s < 0)
|
|
ref.s = s = socket(af, SOCK_STREAM | SOCK_NONBLOCK,
|
|
IPPROTO_TCP);
|
|
|
|
if (s < 0)
|
|
return;
|
|
|
|
tcp_sock_set_bufsize(c, s);
|
|
|
|
if (af == AF_INET && addr4.sin_addr.s_addr == c->gw4)
|
|
addr4.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
|
|
else if (af == AF_INET6 && !memcmp(addr, &c->gw6, sizeof(c->gw6)))
|
|
addr6.sin6_addr = in6addr_loopback;
|
|
|
|
if (af == AF_INET6 && IN6_IS_ADDR_LINKLOCAL(&addr6.sin6_addr)) {
|
|
struct sockaddr_in6 addr6_ll = {
|
|
.sin6_family = AF_INET6,
|
|
.sin6_addr = c->addr6_ll,
|
|
.sin6_scope_id = c->ifi,
|
|
};
|
|
bind(s, (struct sockaddr *)&addr6_ll, sizeof(addr6_ll));
|
|
}
|
|
|
|
conn = &tt[c->tcp.tap_conn_count++];
|
|
conn->sock = s;
|
|
conn->events = 0;
|
|
|
|
conn->wnd_to_tap = WINDOW_DEFAULT;
|
|
|
|
conn->mss_guest = tcp_opt_get(th, len, OPT_MSS, NULL, NULL);
|
|
if (conn->mss_guest < 0)
|
|
conn->mss_guest = MSS_DEFAULT;
|
|
|
|
if (c->mode == MODE_PASST) {
|
|
/* Don't upset qemu */
|
|
conn->mss_guest = MIN(USHRT_MAX -
|
|
sizeof(uint32_t) -
|
|
sizeof(struct ethhdr) -
|
|
sizeof(struct ipv6hdr) -
|
|
sizeof(struct tcphdr),
|
|
conn->mss_guest);
|
|
}
|
|
|
|
sl = sizeof(conn->mss_guest);
|
|
setsockopt(s, SOL_TCP, TCP_MAXSEG, &conn->mss_guest, sl);
|
|
|
|
tcp_clamp_window(conn, th, len, 0, 1);
|
|
|
|
if (af == AF_INET) {
|
|
sa = (struct sockaddr *)&addr4;
|
|
sl = sizeof(addr4);
|
|
|
|
memset(&conn->a.a4.zero, 0, sizeof(conn->a.a4.zero));
|
|
memset(&conn->a.a4.one, 0xff, sizeof(conn->a.a4.one));
|
|
memcpy(&conn->a.a4.a, addr, sizeof(conn->a.a4.a));
|
|
} else {
|
|
sa = (struct sockaddr *)&addr6;
|
|
sl = sizeof(addr6);
|
|
|
|
memcpy(&conn->a.a6, addr, sizeof(conn->a.a6));
|
|
}
|
|
|
|
conn->sock_port = ntohs(th->dest);
|
|
conn->tap_port = ntohs(th->source);
|
|
|
|
conn->ts_sock_act = conn->ts_tap_act = *now;
|
|
conn->ts_ack_to_tap = conn->ts_ack_from_tap = *now;
|
|
|
|
conn->seq_init_from_tap = ntohl(th->seq);
|
|
conn->seq_from_tap = conn->seq_init_from_tap + 1;
|
|
conn->seq_ack_to_tap = conn->seq_from_tap;
|
|
|
|
conn->seq_to_tap = tcp_seq_init(c, af, addr, th->dest, th->source, now);
|
|
conn->seq_init_to_tap = conn->seq_to_tap;
|
|
conn->seq_ack_from_tap = conn->seq_to_tap + 1;
|
|
|
|
tcp_hash_insert(c, conn, af, addr);
|
|
|
|
if (!bind(s, sa, sl))
|
|
tcp_rst(c, conn); /* Nobody is listening then */
|
|
if (errno != EADDRNOTAVAIL)
|
|
conn->local = 1;
|
|
|
|
if (connect(s, sa, sl)) {
|
|
tcp_tap_state(conn, TAP_SYN_SENT);
|
|
|
|
if (errno != EINPROGRESS) {
|
|
tcp_rst(c, conn);
|
|
return;
|
|
}
|
|
|
|
ev.events = EPOLLOUT | EPOLLRDHUP;
|
|
|
|
tcp_get_sndbuf(conn);
|
|
} else {
|
|
tcp_tap_state(conn, TAP_SYN_RCVD);
|
|
|
|
tcp_get_sndbuf(conn);
|
|
|
|
if (tcp_send_to_tap(c, conn, SYN | ACK, now))
|
|
return;
|
|
|
|
ev.events = EPOLLIN | EPOLLRDHUP;
|
|
}
|
|
|
|
conn->events = ev.events;
|
|
ref.tcp.index = conn - tt;
|
|
ev.data.u64 = ref.u64;
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_ADD, s, &ev);
|
|
}
|
|
|
|
/**
|
|
* tcp_table_splice_compact - Compact spliced connection table
|
|
* @c: Execution context
|
|
* @hole: Pointer to recently closed connection
|
|
*/
|
|
static void tcp_table_splice_compact(struct ctx *c,
|
|
struct tcp_splice_conn *hole)
|
|
{
|
|
union epoll_ref ref_from = { .proto = IPPROTO_TCP, .tcp.splice = 1,
|
|
.tcp.index = hole - ts };
|
|
union epoll_ref ref_to = { .proto = IPPROTO_TCP, .tcp.splice = 1,
|
|
.tcp.index = hole - ts };
|
|
struct tcp_splice_conn *move;
|
|
struct epoll_event ev_from;
|
|
struct epoll_event ev_to;
|
|
|
|
hole->from_fin_sent = hole->to_fin_sent = 0;
|
|
hole->from_read = hole->from_written = 0;
|
|
hole->to_read = hole->to_written = 0;
|
|
|
|
bitmap_clear(splice_rcvlowat_set[0], hole - ts);
|
|
bitmap_clear(splice_rcvlowat_set[1], hole - ts);
|
|
bitmap_clear(splice_rcvlowat_act[0], hole - ts);
|
|
bitmap_clear(splice_rcvlowat_act[1], hole - ts);
|
|
|
|
if ((hole - ts) == --c->tcp.splice_conn_count)
|
|
return;
|
|
|
|
move = &ts[c->tcp.splice_conn_count];
|
|
if (move->state == CLOSED)
|
|
return;
|
|
|
|
memcpy(hole, move, sizeof(*hole));
|
|
move->state = CLOSED;
|
|
move = hole;
|
|
|
|
ref_from.s = move->from;
|
|
ref_from.tcp.v6 = move->v6;
|
|
ref_to.s = move->to;
|
|
ref_to.tcp.v6 = move->v6;
|
|
|
|
if (move->state == SPLICE_ACCEPTED) {
|
|
ev_from.events = ev_to.events = 0;
|
|
} else if (move->state == SPLICE_CONNECT) {
|
|
ev_from.events = 0;
|
|
ev_to.events = EPOLLOUT;
|
|
} else {
|
|
ev_from.events = EPOLLIN | EPOLLOUT | EPOLLRDHUP;
|
|
ev_to.events = EPOLLIN | EPOLLOUT | EPOLLRDHUP;
|
|
}
|
|
|
|
ev_from.data.u64 = ref_from.u64;
|
|
ev_to.data.u64 = ref_to.u64;
|
|
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_MOD, move->from, &ev_from);
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_MOD, move->to, &ev_to);
|
|
}
|
|
|
|
/**
|
|
* tcp_splice_destroy() - Close spliced connection and pipes, drop from epoll
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
*/
|
|
static void tcp_splice_destroy(struct ctx *c, struct tcp_splice_conn *conn)
|
|
{
|
|
int epoll_del_done = 0;
|
|
|
|
switch (conn->state) {
|
|
case CLOSED:
|
|
epoll_del_done = 1;
|
|
/* Falls through */
|
|
case SPLICE_FIN_BOTH:
|
|
case SPLICE_FIN_FROM:
|
|
case SPLICE_FIN_TO:
|
|
case SPLICE_ESTABLISHED:
|
|
/* Flushing might need to block: don't recycle them. */
|
|
if (conn->pipe_from_to[0] != -1) {
|
|
close(conn->pipe_from_to[0]);
|
|
conn->pipe_from_to[0] = -1;
|
|
close(conn->pipe_from_to[1]);
|
|
conn->pipe_from_to[1] = -1;
|
|
}
|
|
if (conn->pipe_to_from[0] != -1) {
|
|
close(conn->pipe_to_from[0]);
|
|
conn->pipe_to_from[0] = -1;
|
|
close(conn->pipe_to_from[1]);
|
|
conn->pipe_to_from[1] = -1;
|
|
}
|
|
/* Falls through */
|
|
case SPLICE_CONNECT:
|
|
if (!epoll_del_done) {
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_DEL, conn->from, NULL);
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_DEL, conn->to, NULL);
|
|
}
|
|
close(conn->to);
|
|
/* Falls through */
|
|
case SPLICE_ACCEPTED:
|
|
close(conn->from);
|
|
tcp_splice_state(conn, CLOSED);
|
|
tcp_table_splice_compact(c, conn);
|
|
break;
|
|
default:
|
|
return;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* tcp_sock_consume() - Consume (discard) data from buffer, update ACK sequence
|
|
* @conn: Connection pointer
|
|
* @ack_seq: ACK sequence, host order
|
|
*/
|
|
static void tcp_sock_consume(struct tcp_tap_conn *conn, uint32_t ack_seq)
|
|
{
|
|
/* Simply ignore out-of-order ACKs: we already consumed the data we
|
|
* needed from the buffer, and we won't rewind back to a lower ACK
|
|
* sequence.
|
|
*/
|
|
if (SEQ_LE(ack_seq, conn->seq_ack_from_tap))
|
|
return;
|
|
|
|
recv(conn->sock, NULL, ack_seq - conn->seq_ack_from_tap,
|
|
MSG_DONTWAIT | MSG_TRUNC);
|
|
|
|
conn->seq_ack_from_tap = ack_seq;
|
|
}
|
|
|
|
/**
|
|
* tcp_data_from_sock() - Handle new data from socket, queue to tap, in window
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
* @now: Current timestamp
|
|
*
|
|
* Return: negative on connection reset, 0 otherwise
|
|
*/
|
|
static int tcp_data_from_sock(struct ctx *c, struct tcp_tap_conn *conn,
|
|
struct timespec *now)
|
|
{
|
|
int *buf_mss, *buf_mss_nr_set, *buf_mss_tap, *buf_mss_tap_nr_set;
|
|
int mss_tap, fill_bufs, send_bufs = 0, last_len, iov_rem = 0;
|
|
int send, len, plen, v4 = CONN_V4(conn);
|
|
uint32_t seq_to_tap = conn->seq_to_tap;
|
|
int s = conn->sock, i, ret = 0;
|
|
struct iovec *iov, *iov_tap;
|
|
uint32_t already_sent;
|
|
struct mmsghdr *mh;
|
|
|
|
already_sent = conn->seq_to_tap - conn->seq_ack_from_tap;
|
|
|
|
if (SEQ_LT(already_sent, 0)) {
|
|
/* RFC 761, section 2.1. */
|
|
seq_to_tap = conn->seq_to_tap = conn->seq_ack_from_tap;
|
|
already_sent = 0;
|
|
}
|
|
|
|
if (!conn->wnd_from_tap || already_sent >= conn->wnd_from_tap) {
|
|
tcp_tap_epoll_mask(c, conn, conn->events | EPOLLET);
|
|
return 0;
|
|
}
|
|
|
|
fill_bufs = DIV_ROUND_UP(conn->wnd_from_tap - already_sent,
|
|
conn->mss_guest);
|
|
if (fill_bufs > TCP_TAP_FRAMES) {
|
|
fill_bufs = TCP_TAP_FRAMES;
|
|
iov_rem = 0;
|
|
} else {
|
|
iov_rem = (conn->wnd_from_tap - already_sent) % conn->mss_guest;
|
|
}
|
|
|
|
/* Adjust iovec length for recvmsg() based on what was set last time. */
|
|
if (v4) {
|
|
iov = tcp4_l2_iov_sock + 1;
|
|
buf_mss = &tcp4_l2_buf_mss;
|
|
buf_mss_nr_set = &tcp4_l2_buf_mss_nr_set;
|
|
} else {
|
|
iov = tcp6_l2_iov_sock + 1;
|
|
buf_mss = &tcp6_l2_buf_mss;
|
|
buf_mss_nr_set = &tcp6_l2_buf_mss_nr_set;
|
|
}
|
|
if (*buf_mss != conn->mss_guest)
|
|
*buf_mss_nr_set = 0;
|
|
for (i = *buf_mss_nr_set; i < fill_bufs; i++)
|
|
iov[i].iov_len = conn->mss_guest;
|
|
*buf_mss = conn->mss_guest;
|
|
*buf_mss_nr_set = fill_bufs - 1;
|
|
|
|
/* First buffer is to discard data, last one may be partially filled. */
|
|
iov[-1].iov_len = already_sent;
|
|
if (iov_rem)
|
|
iov[fill_bufs - 1].iov_len = iov_rem;
|
|
if (v4)
|
|
tcp4_l2_mh_sock.msg_iovlen = fill_bufs + 1;
|
|
else
|
|
tcp6_l2_mh_sock.msg_iovlen = fill_bufs + 1;
|
|
|
|
/* Don't dequeue until acknowledged by guest. */
|
|
recvmsg:
|
|
len = recvmsg(s, v4 ? &tcp4_l2_mh_sock : &tcp6_l2_mh_sock, MSG_PEEK);
|
|
if (len < 0) {
|
|
if (errno == EINTR)
|
|
goto recvmsg;
|
|
goto err;
|
|
}
|
|
|
|
if (!len)
|
|
goto zero_len;
|
|
|
|
send = len - already_sent;
|
|
if (send <= 0) {
|
|
tcp_tap_epoll_mask(c, conn, conn->events | EPOLLET);
|
|
goto out;
|
|
}
|
|
|
|
tcp_tap_epoll_mask(c, conn, conn->events & ~EPOLLET);
|
|
|
|
send_bufs = DIV_ROUND_UP(send, conn->mss_guest);
|
|
last_len = send - (send_bufs - 1) * conn->mss_guest;
|
|
|
|
/* Adjust iovec length for sending based on what was set last time. */
|
|
if (v4) {
|
|
mss_tap = conn->mss_guest +
|
|
offsetof(struct tcp4_l2_buf_t, data) -
|
|
offsetof(struct tcp4_l2_buf_t, vnet_len);
|
|
|
|
iov_tap = tcp4_l2_iov_tap;
|
|
buf_mss_tap = &tcp4_l2_buf_mss_tap;
|
|
buf_mss_tap_nr_set = &tcp4_l2_buf_mss_tap_nr_set;
|
|
} else {
|
|
mss_tap = conn->mss_guest +
|
|
offsetof(struct tcp6_l2_buf_t, data) -
|
|
offsetof(struct tcp6_l2_buf_t, vnet_len);
|
|
|
|
iov_tap = tcp6_l2_iov_tap;
|
|
buf_mss_tap = &tcp6_l2_buf_mss_tap;
|
|
buf_mss_tap_nr_set = &tcp6_l2_buf_mss_tap_nr_set;
|
|
}
|
|
if (*buf_mss_tap != mss_tap)
|
|
*buf_mss_tap_nr_set = 0;
|
|
for (i = *buf_mss_tap_nr_set; i < send_bufs; i++)
|
|
iov_tap[i].iov_len = mss_tap;
|
|
*buf_mss_tap = mss_tap;
|
|
*buf_mss_tap_nr_set = send_bufs;
|
|
|
|
iov_tap[send_bufs - 1].iov_len = mss_tap - conn->mss_guest + last_len;
|
|
|
|
/* Likely, some new data was acked too. */
|
|
tcp_update_seqack_wnd(c, conn, 0, NULL);
|
|
|
|
plen = conn->mss_guest;
|
|
for (i = 0, mh = tcp_l2_mh_tap; i < send_bufs; i++, mh++) {
|
|
ssize_t eth_len;
|
|
|
|
if (i == send_bufs - 1)
|
|
plen = last_len;
|
|
|
|
if (v4) {
|
|
struct tcp4_l2_buf_t *b = &tcp4_l2_buf[i];
|
|
uint16_t *check = NULL;
|
|
|
|
if (i && i != send_bufs - 1)
|
|
check = &tcp4_l2_buf[0].iph.check;
|
|
|
|
eth_len = tcp_l2_buf_fill_headers(c, conn, b, plen,
|
|
check, seq_to_tap);
|
|
|
|
if (c->mode == MODE_PASST) {
|
|
mh->msg_hdr.msg_iov = &tcp4_l2_iov_tap[i];
|
|
seq_to_tap += plen;
|
|
continue;
|
|
}
|
|
|
|
pcap((char *)&b->eh, eth_len);
|
|
ret = write(c->fd_tap, &b->eh, eth_len);
|
|
} else {
|
|
struct tcp6_l2_buf_t *b = &tcp6_l2_buf[i];
|
|
|
|
eth_len = tcp_l2_buf_fill_headers(c, conn, b, plen,
|
|
NULL, seq_to_tap);
|
|
|
|
if (c->mode == MODE_PASST) {
|
|
mh->msg_hdr.msg_iov = &tcp6_l2_iov_tap[i];
|
|
seq_to_tap += plen;
|
|
continue;
|
|
}
|
|
|
|
pcap((char *)&b->eh, eth_len);
|
|
ret = write(c->fd_tap, &b->eh, eth_len);
|
|
}
|
|
|
|
if (ret < eth_len) {
|
|
if (ret < 0) {
|
|
if (errno == EAGAIN || errno == EWOULDBLOCK)
|
|
return 0;
|
|
|
|
tap_handler(c, EPOLLERR, now);
|
|
}
|
|
|
|
i--;
|
|
continue;
|
|
}
|
|
|
|
conn->seq_to_tap += plen;
|
|
}
|
|
|
|
if (c->mode == MODE_PASTA)
|
|
goto out;
|
|
|
|
sendmmsg:
|
|
ret = sendmmsg(c->fd_tap, tcp_l2_mh_tap, mh - tcp_l2_mh_tap,
|
|
MSG_NOSIGNAL | MSG_DONTWAIT);
|
|
if (ret < 0 && errno == EINTR)
|
|
goto sendmmsg;
|
|
|
|
if (ret <= 0)
|
|
goto out;
|
|
|
|
conn->tap_data_noack = *now;
|
|
conn->seq_to_tap += conn->mss_guest * (ret - 1) + last_len;
|
|
|
|
/* sendmmsg() indicates how many messages were sent at least partially.
|
|
* Kernel commit 3023898b7d4a ("sock: fix sendmmsg for partial sendmsg")
|
|
* gives us the guarantee that at most one message, namely the last sent
|
|
* one, might have been sent partially. Check how many bytes of that
|
|
* message were sent, and re-send any missing bytes with a blocking
|
|
* sendmsg(), otherwise qemu will fail to parse any subsequent message.
|
|
*/
|
|
mh = &tcp_l2_mh_tap[ret - 1];
|
|
if (mh->msg_len < mh->msg_hdr.msg_iov->iov_len) {
|
|
uint8_t **iov_base = (uint8_t **)&mh->msg_hdr.msg_iov->iov_base;
|
|
int part_sent = mh->msg_len;
|
|
|
|
mh->msg_hdr.msg_iov->iov_len -= part_sent;
|
|
*iov_base += part_sent;
|
|
|
|
sendmsg(c->fd_tap, &mh->msg_hdr, MSG_NOSIGNAL);
|
|
|
|
mh->msg_hdr.msg_iov->iov_len += part_sent;
|
|
*iov_base -= part_sent;
|
|
}
|
|
|
|
conn->ts_ack_to_tap = *now;
|
|
|
|
pcapmm(tcp_l2_mh_tap, ret);
|
|
|
|
goto out;
|
|
|
|
err:
|
|
if (errno != EAGAIN && errno != EWOULDBLOCK) {
|
|
tcp_rst(c, conn);
|
|
ret = -errno;
|
|
}
|
|
goto out;
|
|
|
|
zero_len:
|
|
if (conn->state == ESTABLISHED_SOCK_FIN) {
|
|
tcp_tap_epoll_mask(c, conn, EPOLLET);
|
|
tcp_send_to_tap(c, conn, FIN | ACK, now);
|
|
tcp_tap_state(conn, ESTABLISHED_SOCK_FIN_SENT);
|
|
}
|
|
|
|
out:
|
|
if (iov_rem)
|
|
iov[fill_bufs - 1].iov_len = conn->mss_guest;
|
|
if (send_bufs)
|
|
iov_tap[send_bufs - 1].iov_len = mss_tap;
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* tcp_data_from_tap() - tap data in ESTABLISHED{,SOCK_FIN}, CLOSE_WAIT states
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
* @msg: Array of messages from tap
|
|
* @count: Count of messages
|
|
* @now: Current timestamp
|
|
*/
|
|
static void tcp_data_from_tap(struct ctx *c, struct tcp_tap_conn *conn,
|
|
struct tap_l4_msg *msg, int count,
|
|
struct timespec *now)
|
|
{
|
|
int i, iov_i, ack = 0, fin = 0, retr = 0, keep = -1;
|
|
struct msghdr mh = { .msg_iov = tcp_tap_iov };
|
|
uint32_t max_ack_seq = conn->seq_ack_from_tap;
|
|
uint16_t max_ack_seq_wnd = conn->wnd_from_tap;
|
|
uint32_t seq_from_tap = conn->seq_from_tap;
|
|
int partial_send = 0;
|
|
uint16_t len;
|
|
ssize_t n;
|
|
|
|
for (i = 0, iov_i = 0; i < count; i++) {
|
|
uint32_t seq, seq_offset, ack_seq;
|
|
struct tcphdr *th;
|
|
char *data;
|
|
size_t off;
|
|
|
|
th = (struct tcphdr *)(pkt_buf + msg[i].pkt_buf_offset);
|
|
len = msg[i].l4_len;
|
|
|
|
if (len < sizeof(*th)) {
|
|
tcp_rst(c, conn);
|
|
return;
|
|
}
|
|
|
|
off = th->doff * 4;
|
|
if (off < sizeof(*th) || off > len) {
|
|
tcp_rst(c, conn);
|
|
return;
|
|
}
|
|
|
|
if (th->rst) {
|
|
tcp_tap_destroy(c, conn);
|
|
return;
|
|
}
|
|
|
|
len -= off;
|
|
data = (char *)th + off;
|
|
|
|
seq = ntohl(th->seq);
|
|
ack_seq = ntohl(th->ack_seq);
|
|
|
|
if (th->ack) {
|
|
ack = 1;
|
|
|
|
if (SEQ_GE(ack_seq, conn->seq_ack_from_tap) &&
|
|
SEQ_GE(ack_seq, max_ack_seq)) {
|
|
/* Fast re-transmit */
|
|
retr = !len && !th->fin &&
|
|
ack_seq == max_ack_seq &&
|
|
max_ack_seq_wnd == ntohs(th->window);
|
|
|
|
max_ack_seq_wnd = ntohs(th->window);
|
|
max_ack_seq = ack_seq;
|
|
}
|
|
}
|
|
|
|
if (th->fin)
|
|
fin = 1;
|
|
|
|
if (!len)
|
|
continue;
|
|
|
|
seq_offset = seq_from_tap - seq;
|
|
/* Use data from this buffer only in these two cases:
|
|
*
|
|
* , seq_from_tap , seq_from_tap
|
|
* |--------| <-- len |--------| <-- len
|
|
* '----' <-- offset ' <-- offset
|
|
* ^ seq ^ seq
|
|
* (offset >= 0, seq + len > seq_from_tap)
|
|
*
|
|
* discard in these two cases:
|
|
* , seq_from_tap , seq_from_tap
|
|
* |--------| <-- len |--------| <-- len
|
|
* '--------' <-- offset '-----| <- offset
|
|
* ^ seq ^ seq
|
|
* (offset >= 0, seq + len <= seq_from_tap)
|
|
*
|
|
* keep, look for another buffer, then go back, in this case:
|
|
* , seq_from_tap
|
|
* |--------| <-- len
|
|
* '===' <-- offset
|
|
* ^ seq
|
|
* (offset < 0)
|
|
*/
|
|
if (SEQ_GE(seq_offset, 0) && SEQ_LE(seq + len, seq_from_tap))
|
|
continue;
|
|
|
|
if (SEQ_LT(seq_offset, 0)) {
|
|
if (keep == -1)
|
|
keep = i;
|
|
continue;
|
|
}
|
|
|
|
tcp_tap_iov[iov_i].iov_base = data + seq_offset;
|
|
tcp_tap_iov[iov_i].iov_len = len - seq_offset;
|
|
seq_from_tap += tcp_tap_iov[iov_i].iov_len;
|
|
iov_i++;
|
|
|
|
if (keep == i)
|
|
keep = -1;
|
|
|
|
if (keep != -1)
|
|
i = keep - 1;
|
|
}
|
|
|
|
tcp_clamp_window(conn, NULL, 0, max_ack_seq_wnd, 0);
|
|
|
|
if (ack) {
|
|
conn->ts_ack_from_tap = *now;
|
|
conn->tap_data_noack = ((struct timespec) { 0, 0 });
|
|
tcp_sock_consume(conn, max_ack_seq);
|
|
}
|
|
|
|
if (retr) {
|
|
conn->seq_ack_from_tap = max_ack_seq;
|
|
conn->seq_to_tap = max_ack_seq;
|
|
tcp_data_from_sock(c, conn, now);
|
|
}
|
|
|
|
if (!iov_i)
|
|
goto out;
|
|
|
|
mh.msg_iovlen = iov_i;
|
|
eintr:
|
|
n = sendmsg(conn->sock, &mh, MSG_DONTWAIT | MSG_NOSIGNAL);
|
|
if (n < 0) {
|
|
if (errno == EPIPE) {
|
|
/* Here's the wrap, said the tap.
|
|
* In my pocket, said the socket.
|
|
* Then swiftly looked away and left.
|
|
*/
|
|
conn->seq_from_tap = seq_from_tap;
|
|
tcp_send_to_tap(c, conn, FORCE_ACK, now);
|
|
}
|
|
|
|
if (errno == EINTR)
|
|
goto eintr;
|
|
|
|
if (errno == EAGAIN || errno == EWOULDBLOCK) {
|
|
tcp_send_to_tap(c, conn, 0, now);
|
|
return;
|
|
}
|
|
tcp_rst(c, conn);
|
|
return;
|
|
}
|
|
|
|
|
|
if (n < (seq_from_tap - conn->seq_from_tap)) {
|
|
partial_send = 1;
|
|
conn->seq_from_tap += n;
|
|
tcp_send_to_tap(c, conn, 0, now);
|
|
} else {
|
|
conn->seq_from_tap += n;
|
|
}
|
|
|
|
out:
|
|
if (keep != -1) {
|
|
if (conn->seq_dup_ack != conn->seq_from_tap) {
|
|
conn->seq_dup_ack = conn->seq_from_tap;
|
|
tcp_send_to_tap(c, conn, DUP_ACK, now);
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (ack) {
|
|
if (conn->state == ESTABLISHED_SOCK_FIN_SENT &&
|
|
conn->seq_ack_from_tap == conn->seq_to_tap)
|
|
tcp_tap_state(conn, CLOSE_WAIT);
|
|
}
|
|
|
|
if (fin && !partial_send) {
|
|
conn->seq_from_tap++;
|
|
|
|
if (conn->state == ESTABLISHED) {
|
|
shutdown(conn->sock, SHUT_WR);
|
|
tcp_tap_state(conn, FIN_WAIT_1);
|
|
tcp_send_to_tap(c, conn, ACK, now);
|
|
} else if (conn->state == CLOSE_WAIT) {
|
|
shutdown(conn->sock, SHUT_WR);
|
|
tcp_tap_state(conn, LAST_ACK);
|
|
tcp_send_to_tap(c, conn, ACK, now);
|
|
}
|
|
} else {
|
|
tcp_send_to_tap(c, conn, 0, now);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* tcp_tap_handler() - Handle packets from tap and state transitions
|
|
* @c: Execution context
|
|
* @af: Address family, AF_INET or AF_INET6
|
|
* @addr: Destination address
|
|
* @msg: Input messages
|
|
* @count: Message count
|
|
* @now: Current timestamp
|
|
*
|
|
* Return: count of consumed packets
|
|
*/
|
|
int tcp_tap_handler(struct ctx *c, int af, void *addr,
|
|
struct tap_l4_msg *msg, int count, struct timespec *now)
|
|
{
|
|
struct tcphdr *th = (struct tcphdr *)(pkt_buf + msg[0].pkt_buf_offset);
|
|
uint16_t len = msg[0].l4_len;
|
|
struct tcp_tap_conn *conn;
|
|
|
|
conn = tcp_hash_lookup(c, af, addr, htons(th->source), htons(th->dest));
|
|
if (!conn) {
|
|
if (th->syn && !th->ack)
|
|
tcp_conn_from_tap(c, af, addr, th, len, now);
|
|
return 1;
|
|
}
|
|
|
|
if (th->rst) {
|
|
tcp_tap_destroy(c, conn);
|
|
return count;
|
|
}
|
|
|
|
conn->ts_tap_act = *now;
|
|
|
|
switch (conn->state) {
|
|
case SOCK_SYN_SENT:
|
|
if (!th->syn || !th->ack) {
|
|
tcp_rst(c, conn);
|
|
return count;
|
|
}
|
|
|
|
tcp_clamp_window(conn, th, len, 0, 1);
|
|
|
|
conn->mss_guest = tcp_opt_get(th, len, OPT_MSS, NULL, NULL);
|
|
if (conn->mss_guest < 0)
|
|
conn->mss_guest = MSS_DEFAULT;
|
|
|
|
if (c->mode == MODE_PASST) {
|
|
/* Don't upset qemu */
|
|
conn->mss_guest = MIN(USHRT_MAX -
|
|
sizeof(uint32_t) -
|
|
sizeof(struct ethhdr) -
|
|
sizeof(struct ipv6hdr) -
|
|
sizeof(struct tcphdr),
|
|
conn->mss_guest);
|
|
}
|
|
|
|
/* info.tcpi_bytes_acked already includes one byte for SYN, but
|
|
* not for incoming connections.
|
|
*/
|
|
conn->seq_init_from_tap = ntohl(th->seq) + 1;
|
|
conn->seq_from_tap = conn->seq_init_from_tap;
|
|
conn->seq_ack_to_tap = conn->seq_from_tap;
|
|
|
|
tcp_tap_state(conn, ESTABLISHED);
|
|
|
|
/* The client might have sent data already, which we didn't
|
|
* dequeue waiting for SYN,ACK from tap -- check now.
|
|
*/
|
|
tcp_data_from_sock(c, conn, now);
|
|
tcp_send_to_tap(c, conn, 0, now);
|
|
|
|
tcp_tap_epoll_mask(c, conn, EPOLLIN | EPOLLRDHUP);
|
|
break;
|
|
case TAP_SYN_RCVD:
|
|
if (th->fin) {
|
|
conn->seq_from_tap++;
|
|
|
|
shutdown(conn->sock, SHUT_WR);
|
|
tcp_send_to_tap(c, conn, ACK, now);
|
|
tcp_tap_state(conn, FIN_WAIT_1);
|
|
break;
|
|
}
|
|
|
|
if (!th->ack) {
|
|
tcp_rst(c, conn);
|
|
return count;
|
|
}
|
|
|
|
tcp_clamp_window(conn, th, len, 0, 0);
|
|
|
|
tcp_tap_state(conn, ESTABLISHED);
|
|
if (count == 1)
|
|
break;
|
|
|
|
/* Falls through */
|
|
case ESTABLISHED:
|
|
case ESTABLISHED_SOCK_FIN:
|
|
case ESTABLISHED_SOCK_FIN_SENT:
|
|
tcp_tap_epoll_mask(c, conn, conn->events & ~EPOLLET);
|
|
tcp_data_from_tap(c, conn, msg, count, now);
|
|
return count;
|
|
case CLOSE_WAIT:
|
|
case FIN_WAIT_1_SOCK_FIN:
|
|
case FIN_WAIT_1:
|
|
if (th->ack) {
|
|
conn->tap_data_noack = ((struct timespec) { 0, 0 });
|
|
conn->ts_ack_from_tap = *now;
|
|
}
|
|
|
|
tcp_sock_consume(conn, ntohl(th->ack_seq));
|
|
if (conn->state == FIN_WAIT_1_SOCK_FIN &&
|
|
conn->seq_ack_from_tap == conn->seq_to_tap) {
|
|
tcp_tap_destroy(c, conn);
|
|
return count;
|
|
}
|
|
|
|
tcp_tap_epoll_mask(c, conn, conn->events & ~EPOLLET);
|
|
return count;
|
|
case TAP_SYN_SENT:
|
|
case LAST_ACK:
|
|
case SPLICE_ACCEPTED:
|
|
case SPLICE_CONNECT:
|
|
case SPLICE_ESTABLISHED:
|
|
case SPLICE_FIN_FROM:
|
|
case SPLICE_FIN_TO:
|
|
case SPLICE_FIN_BOTH:
|
|
case CLOSED: /* ;) */
|
|
break;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* tcp_connect_finish() - Handle completion of connect() from EPOLLOUT event
|
|
* @c: Execution context
|
|
* @s: File descriptor number for socket
|
|
* @now: Current timestamp
|
|
*/
|
|
static void tcp_connect_finish(struct ctx *c, struct tcp_tap_conn *conn,
|
|
struct timespec *now)
|
|
{
|
|
socklen_t sl;
|
|
int so;
|
|
|
|
/* Drop EPOLLOUT, only used to wait for connect() to complete */
|
|
tcp_tap_epoll_mask(c, conn, EPOLLIN | EPOLLRDHUP);
|
|
|
|
sl = sizeof(so);
|
|
if (getsockopt(conn->sock, SOL_SOCKET, SO_ERROR, &so, &sl) || so) {
|
|
tcp_rst(c, conn);
|
|
return;
|
|
}
|
|
|
|
if (tcp_send_to_tap(c, conn, SYN | ACK, now))
|
|
return;
|
|
|
|
tcp_tap_state(conn, TAP_SYN_RCVD);
|
|
}
|
|
|
|
/**
|
|
* tcp_splice_connect_finish() - Completion of connect() or call on success
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
* @v6: Set on IPv6 connection
|
|
*/
|
|
static void tcp_splice_connect_finish(struct ctx *c,
|
|
struct tcp_splice_conn *conn, int v6)
|
|
{
|
|
union epoll_ref ref_from = { .proto = IPPROTO_TCP, .s = conn->from,
|
|
.tcp = { .splice = 1, .v6 = v6,
|
|
.index = conn - ts } };
|
|
union epoll_ref ref_to = { .proto = IPPROTO_TCP, .s = conn->to,
|
|
.tcp = { .splice = 1, .v6 = v6,
|
|
.index = conn - ts } };
|
|
struct epoll_event ev_from, ev_to;
|
|
int i;
|
|
|
|
conn->pipe_from_to[0] = conn->pipe_to_from[0] = -1;
|
|
conn->pipe_from_to[1] = conn->pipe_to_from[1] = -1;
|
|
for (i = 0; i < TCP_SPLICE_PIPE_POOL_SIZE; i++) {
|
|
if (splice_pipe_pool[i][0][0] > 0) {
|
|
SWAP(conn->pipe_from_to[0], splice_pipe_pool[i][0][0]);
|
|
SWAP(conn->pipe_from_to[1], splice_pipe_pool[i][0][1]);
|
|
|
|
SWAP(conn->pipe_to_from[0], splice_pipe_pool[i][1][0]);
|
|
SWAP(conn->pipe_to_from[1], splice_pipe_pool[i][1][1]);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (conn->pipe_from_to[0] <= 0) {
|
|
if (pipe2(conn->pipe_to_from, O_NONBLOCK) ||
|
|
pipe2(conn->pipe_from_to, O_NONBLOCK)) {
|
|
tcp_splice_destroy(c, conn);
|
|
return;
|
|
}
|
|
|
|
fcntl(conn->pipe_from_to[0], F_SETPIPE_SZ, c->tcp.pipe_size);
|
|
fcntl(conn->pipe_to_from[0], F_SETPIPE_SZ, c->tcp.pipe_size);
|
|
}
|
|
|
|
if (conn->state == SPLICE_CONNECT) {
|
|
tcp_splice_state(conn, SPLICE_ESTABLISHED);
|
|
|
|
ev_from.events = ev_to.events = EPOLLIN | EPOLLRDHUP;
|
|
ev_from.data.u64 = ref_from.u64;
|
|
ev_to.data.u64 = ref_to.u64;
|
|
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_ADD, conn->from, &ev_from);
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_MOD, conn->to, &ev_to);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* tcp_splice_connect() - Create and connect socket for new spliced connection
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
* @v6: Set on IPv6 connection
|
|
* @port: Destination port, host order
|
|
*
|
|
* Return: 0 for connect() succeeded or in progress, negative value on error
|
|
*/
|
|
static int tcp_splice_connect(struct ctx *c, struct tcp_splice_conn *conn,
|
|
int s, int v6, in_port_t port)
|
|
{
|
|
int sock_conn = (s > 0) ? s : socket(v6 ? AF_INET6 : AF_INET,
|
|
SOCK_STREAM | SOCK_NONBLOCK,
|
|
IPPROTO_TCP);
|
|
union epoll_ref ref_accept = { .proto = IPPROTO_TCP, .s = conn->from,
|
|
.tcp = { .splice = 1, .v6 = v6,
|
|
.index = conn - ts } };
|
|
union epoll_ref ref_conn = { .proto = IPPROTO_TCP, .s = sock_conn,
|
|
.tcp = { .splice = 1, .v6 = v6,
|
|
.index = conn - ts } };
|
|
struct epoll_event ev_accept = { .data.u64 = ref_accept.u64 };
|
|
struct epoll_event ev_conn = { .data.u64 = ref_conn.u64 };
|
|
struct sockaddr_in6 addr6 = {
|
|
.sin6_family = AF_INET6,
|
|
.sin6_port = htons(port),
|
|
.sin6_addr = IN6ADDR_LOOPBACK_INIT,
|
|
};
|
|
struct sockaddr_in addr4 = {
|
|
.sin_family = AF_INET,
|
|
.sin_port = htons(port),
|
|
.sin_addr = { .s_addr = htonl(INADDR_LOOPBACK) },
|
|
};
|
|
const struct sockaddr *sa;
|
|
int ret, one = 1;
|
|
socklen_t sl;
|
|
|
|
conn->to = sock_conn;
|
|
|
|
if (s <= 0)
|
|
tcp_sock_set_bufsize(c, sock_conn);
|
|
|
|
setsockopt(s, SOL_TCP, TCP_QUICKACK, &one, sizeof(one));
|
|
|
|
if (v6) {
|
|
sa = (struct sockaddr *)&addr6;
|
|
sl = sizeof(addr6);
|
|
} else {
|
|
sa = (struct sockaddr *)&addr4;
|
|
sl = sizeof(addr4);
|
|
}
|
|
|
|
if (connect(conn->to, sa, sl)) {
|
|
if (errno != EINPROGRESS) {
|
|
ret = -errno;
|
|
close(sock_conn);
|
|
return ret;
|
|
}
|
|
|
|
tcp_splice_state(conn, SPLICE_CONNECT);
|
|
ev_conn.events = EPOLLOUT;
|
|
} else {
|
|
tcp_splice_state(conn, SPLICE_ESTABLISHED);
|
|
tcp_splice_connect_finish(c, conn, v6);
|
|
|
|
ev_accept.events = EPOLLIN | EPOLLOUT | EPOLLRDHUP;
|
|
ev_conn.events = EPOLLIN | EPOLLOUT | EPOLLRDHUP;
|
|
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_ADD, conn->from, &ev_accept);
|
|
}
|
|
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_ADD, conn->to, &ev_conn);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* struct tcp_splice_connect_ns_arg - Arguments for tcp_splice_connect_ns()
|
|
* @c: Execution context
|
|
* @conn: Accepted inbound connection
|
|
* @v6: Set for inbound IPv6 connection
|
|
* @port: Destination port, host order
|
|
* @ret: Return value of tcp_splice_connect_ns()
|
|
*/
|
|
struct tcp_splice_connect_ns_arg {
|
|
struct ctx *c;
|
|
struct tcp_splice_conn *conn;
|
|
int v6;
|
|
in_port_t port;
|
|
int ret;
|
|
};
|
|
|
|
/**
|
|
* tcp_splice_connect_ns() - Enter namespace and call tcp_splice_connect()
|
|
* @arg: See struct tcp_splice_connect_ns_arg
|
|
*
|
|
* Return: 0
|
|
*/
|
|
static int tcp_splice_connect_ns(void *arg)
|
|
{
|
|
struct tcp_splice_connect_ns_arg *a;
|
|
|
|
a = (struct tcp_splice_connect_ns_arg *)arg;
|
|
ns_enter(a->c);
|
|
a->ret = tcp_splice_connect(a->c, a->conn, -1, a->v6, a->port);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tcp_splice_new() - Handle new inbound, spliced connection
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
* @v6: Set for IPv6 connection
|
|
* @port: Destination port, host order
|
|
*
|
|
* Return: return code from connect()
|
|
*/
|
|
static int tcp_splice_new(struct ctx *c, struct tcp_splice_conn *conn,
|
|
int v6, in_port_t port)
|
|
{
|
|
struct tcp_splice_connect_ns_arg ns_arg = { c, conn, v6, port, 0 };
|
|
int *sock_pool_p, i, s = -1;
|
|
|
|
if (bitmap_isset(c->tcp.port_to_tap, port))
|
|
sock_pool_p = v6 ? ns_sock_pool6 : ns_sock_pool4;
|
|
else
|
|
sock_pool_p = v6 ? init_sock_pool6 : init_sock_pool4;
|
|
|
|
for (i = 0; i < TCP_SOCK_POOL_SIZE; i++, sock_pool_p++) {
|
|
if ((s = *sock_pool_p) > 0) {
|
|
*sock_pool_p = -1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (s <= 0 && bitmap_isset(c->tcp.port_to_tap, port)) {
|
|
NS_CALL(tcp_splice_connect_ns, &ns_arg);
|
|
return ns_arg.ret;
|
|
}
|
|
|
|
return tcp_splice_connect(c, conn, s, v6, port);
|
|
}
|
|
|
|
/**
|
|
* tcp_conn_from_sock() - Handle new connection request from listening socket
|
|
* @c: Execution context
|
|
* @ref: epoll reference of listening socket
|
|
* @now: Current timestamp
|
|
*/
|
|
static void tcp_conn_from_sock(struct ctx *c, union epoll_ref ref,
|
|
struct timespec *now)
|
|
{
|
|
union epoll_ref ref_conn = { .proto = IPPROTO_TCP,
|
|
.tcp.v6 = ref.tcp.v6 };
|
|
struct sockaddr_storage sa;
|
|
struct tcp_tap_conn *conn;
|
|
struct epoll_event ev;
|
|
socklen_t sl;
|
|
int s;
|
|
|
|
if (c->tcp.tap_conn_count >= MAX_TAP_CONNS)
|
|
return;
|
|
|
|
sl = sizeof(sa);
|
|
s = accept4(ref.s, (struct sockaddr *)&sa, &sl, SOCK_NONBLOCK);
|
|
if (s < 0)
|
|
return;
|
|
|
|
conn = &tt[c->tcp.tap_conn_count++];
|
|
ref_conn.tcp.index = conn - tt;
|
|
ref_conn.s = conn->sock = s;
|
|
|
|
if (ref.tcp.v6) {
|
|
struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)&sa;
|
|
|
|
if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr) ||
|
|
!memcmp(&sa6->sin6_addr, &c->addr6_seen, sizeof(c->gw6)) ||
|
|
!memcmp(&sa6->sin6_addr, &c->addr6, sizeof(c->gw6)))
|
|
memcpy(&sa6->sin6_addr, &c->gw6, sizeof(c->gw6));
|
|
|
|
memcpy(&conn->a.a6, &sa6->sin6_addr, sizeof(conn->a.a6));
|
|
|
|
conn->sock_port = ntohs(sa6->sin6_port);
|
|
conn->tap_port = ref.tcp.index;
|
|
|
|
conn->seq_to_tap = tcp_seq_init(c, AF_INET6, &sa6->sin6_addr,
|
|
conn->sock_port,
|
|
conn->tap_port,
|
|
now);
|
|
conn->seq_init_to_tap = conn->seq_to_tap;
|
|
|
|
tcp_hash_insert(c, conn, AF_INET6, &sa6->sin6_addr);
|
|
} else {
|
|
struct sockaddr_in *sa4 = (struct sockaddr_in *)&sa;
|
|
in_addr_t s_addr = ntohl(sa4->sin_addr.s_addr);
|
|
|
|
memset(&conn->a.a4.zero, 0, sizeof(conn->a.a4.zero));
|
|
memset(&conn->a.a4.one, 0xff, sizeof(conn->a.a4.one));
|
|
|
|
if (s_addr >> IN_CLASSA_NSHIFT == IN_LOOPBACKNET ||
|
|
s_addr == INADDR_ANY || s_addr == htonl(c->addr4_seen))
|
|
sa4->sin_addr.s_addr = c->gw4;
|
|
|
|
memcpy(&conn->a.a4.a, &sa4->sin_addr, sizeof(conn->a.a4.a));
|
|
|
|
conn->sock_port = ntohs(sa4->sin_port);
|
|
conn->tap_port = ref.tcp.index;
|
|
|
|
conn->seq_to_tap = tcp_seq_init(c, AF_INET, &sa4->sin_addr,
|
|
conn->sock_port,
|
|
conn->tap_port,
|
|
now);
|
|
conn->seq_init_to_tap = conn->seq_to_tap;
|
|
|
|
tcp_hash_insert(c, conn, AF_INET, &sa4->sin_addr);
|
|
}
|
|
|
|
conn->seq_ack_from_tap = conn->seq_to_tap + 1;
|
|
|
|
conn->wnd_from_tap = WINDOW_DEFAULT;
|
|
|
|
conn->ts_sock_act = conn->ts_tap_act = *now;
|
|
conn->ts_ack_from_tap = conn->ts_ack_to_tap = *now;
|
|
|
|
tcp_send_to_tap(c, conn, SYN, now);
|
|
|
|
conn->events = ev.events = EPOLLRDHUP;
|
|
ev.data.u64 = ref_conn.u64;
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_ADD, conn->sock, &ev);
|
|
|
|
tcp_tap_state(conn, SOCK_SYN_SENT);
|
|
|
|
tcp_get_sndbuf(conn);
|
|
}
|
|
|
|
/**
|
|
* tcp_sock_handler_splice() - Handler for socket mapped to spliced connection
|
|
* @c: Execution context
|
|
* @ref: epoll reference
|
|
* @events: epoll events bitmap
|
|
*/
|
|
void tcp_sock_handler_splice(struct ctx *c, union epoll_ref ref,
|
|
uint32_t events)
|
|
{
|
|
int move_from, move_to, *pipes, eof, never_read;
|
|
uint8_t *rcvlowat_set, *rcvlowat_act;
|
|
uint64_t *seq_read, *seq_write;
|
|
struct tcp_splice_conn *conn;
|
|
struct epoll_event ev;
|
|
|
|
if (ref.tcp.listen) {
|
|
int s, one = 1;
|
|
|
|
if (c->tcp.splice_conn_count >= MAX_SPLICE_CONNS)
|
|
return;
|
|
|
|
if ((s = accept4(ref.s, NULL, NULL, SOCK_NONBLOCK)) < 0)
|
|
return;
|
|
|
|
setsockopt(s, SOL_TCP, TCP_QUICKACK, &one, sizeof(one));
|
|
|
|
conn = &ts[c->tcp.splice_conn_count++];
|
|
conn->from = s;
|
|
tcp_splice_state(conn, SPLICE_ACCEPTED);
|
|
|
|
if (tcp_splice_new(c, conn, ref.tcp.v6, ref.tcp.index))
|
|
tcp_splice_destroy(c, conn);
|
|
|
|
return;
|
|
}
|
|
|
|
conn = &ts[ref.tcp.index];
|
|
|
|
if (events & EPOLLERR)
|
|
goto close;
|
|
|
|
if (conn->state == SPLICE_CONNECT && (events & EPOLLHUP))
|
|
goto close;
|
|
|
|
if (events & EPOLLOUT) {
|
|
struct epoll_event ev = {
|
|
.events = EPOLLIN | EPOLLRDHUP,
|
|
.data.u64 = ref.u64,
|
|
};
|
|
|
|
if (conn->state == SPLICE_CONNECT)
|
|
tcp_splice_connect_finish(c, conn, ref.tcp.v6);
|
|
else if (conn->state == SPLICE_ESTABLISHED)
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_MOD, ref.s, &ev);
|
|
|
|
move_to = ref.s;
|
|
if (ref.s == conn->to) {
|
|
move_from = conn->from;
|
|
pipes = conn->pipe_from_to;
|
|
} else {
|
|
move_from = conn->to;
|
|
pipes = conn->pipe_to_from;
|
|
}
|
|
} else {
|
|
move_from = ref.s;
|
|
if (ref.s == conn->from) {
|
|
move_to = conn->to;
|
|
pipes = conn->pipe_from_to;
|
|
} else {
|
|
move_to = conn->from;
|
|
pipes = conn->pipe_to_from;
|
|
}
|
|
}
|
|
|
|
if (events & EPOLLRDHUP) {
|
|
if (ref.s == conn->from) {
|
|
if (conn->state == SPLICE_ESTABLISHED)
|
|
tcp_splice_state(conn, SPLICE_FIN_FROM);
|
|
else if (conn->state == SPLICE_FIN_TO)
|
|
tcp_splice_state(conn, SPLICE_FIN_BOTH);
|
|
} else {
|
|
if (conn->state == SPLICE_ESTABLISHED)
|
|
tcp_splice_state(conn, SPLICE_FIN_TO);
|
|
else if (conn->state == SPLICE_FIN_FROM)
|
|
tcp_splice_state(conn, SPLICE_FIN_BOTH);
|
|
}
|
|
}
|
|
|
|
swap:
|
|
eof = 0;
|
|
never_read = 1;
|
|
|
|
if (move_from == conn->from) {
|
|
seq_read = &conn->from_read;
|
|
seq_write = &conn->from_written;
|
|
rcvlowat_set = splice_rcvlowat_set[0];
|
|
rcvlowat_act = splice_rcvlowat_act[0];
|
|
} else {
|
|
seq_read = &conn->to_read;
|
|
seq_write = &conn->to_written;
|
|
rcvlowat_set = splice_rcvlowat_set[1];
|
|
rcvlowat_act = splice_rcvlowat_act[1];
|
|
}
|
|
|
|
|
|
while (1) {
|
|
int retry_write = 0, more = 0;
|
|
ssize_t read, to_write = 0, written;
|
|
|
|
retry:
|
|
read = splice(move_from, NULL, pipes[1], NULL, c->tcp.pipe_size,
|
|
SPLICE_F_MOVE);
|
|
if (read < 0) {
|
|
if (errno == EINTR)
|
|
goto retry;
|
|
|
|
if (errno != EAGAIN)
|
|
goto close;
|
|
|
|
to_write = c->tcp.pipe_size;
|
|
} else if (!read) {
|
|
eof = 1;
|
|
to_write = c->tcp.pipe_size;
|
|
} else {
|
|
never_read = 0;
|
|
to_write += read;
|
|
if (read >= (long)c->tcp.pipe_size * 90 / 100)
|
|
more = SPLICE_F_MORE;
|
|
|
|
if (bitmap_isset(rcvlowat_set, conn - ts))
|
|
bitmap_set(rcvlowat_act, conn - ts);
|
|
}
|
|
|
|
eintr:
|
|
written = splice(pipes[0], NULL, move_to, NULL, to_write,
|
|
SPLICE_F_MOVE | more);
|
|
|
|
/* Most common case: skip updating counters. */
|
|
if (read > 0 && read == written) {
|
|
if (read >= (long)c->tcp.pipe_size * 10 / 100)
|
|
continue;
|
|
|
|
if (!bitmap_isset(rcvlowat_set, conn - ts) &&
|
|
read > (long)c->tcp.pipe_size / 10) {
|
|
int lowat = c->tcp.pipe_size / 4;
|
|
|
|
setsockopt(move_from, SOL_SOCKET, SO_RCVLOWAT,
|
|
&lowat, sizeof(lowat));
|
|
|
|
bitmap_set(rcvlowat_set, conn - ts);
|
|
bitmap_set(rcvlowat_act, conn - ts);
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
*seq_read += read > 0 ? read : 0;
|
|
*seq_write += written > 0 ? written : 0;
|
|
|
|
if (written < 0) {
|
|
if (errno == EINTR)
|
|
goto eintr;
|
|
|
|
if (errno != EAGAIN)
|
|
goto close;
|
|
|
|
if (never_read)
|
|
break;
|
|
|
|
if (retry_write--)
|
|
goto retry;
|
|
|
|
ev.events = EPOLLIN | EPOLLOUT | EPOLLRDHUP;
|
|
ref.s = move_to;
|
|
ev.data.u64 = ref.u64,
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_MOD, move_to, &ev);
|
|
break;
|
|
} else if (never_read && written == (long)(c->tcp.pipe_size)) {
|
|
goto retry;
|
|
} else if (!never_read && written < to_write) {
|
|
to_write -= written;
|
|
goto retry;
|
|
}
|
|
|
|
if (eof)
|
|
break;
|
|
}
|
|
|
|
if (*seq_read == *seq_write) {
|
|
if (move_from == conn->from &&
|
|
(conn->state == SPLICE_FIN_FROM ||
|
|
conn->state == SPLICE_FIN_BOTH)) {
|
|
if (!conn->from_fin_sent) {
|
|
shutdown(conn->to, SHUT_WR);
|
|
conn->from_fin_sent = 1;
|
|
|
|
ev.events = 0;
|
|
ref.s = move_from;
|
|
ev.data.u64 = ref.u64,
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_MOD,
|
|
move_from, &ev);
|
|
}
|
|
|
|
if (conn->to_fin_sent)
|
|
goto close;
|
|
} else if (move_from == conn->to &&
|
|
(conn->state == SPLICE_FIN_TO ||
|
|
conn->state == SPLICE_FIN_BOTH)) {
|
|
if (!conn->to_fin_sent) {
|
|
shutdown(conn->from, SHUT_WR);
|
|
conn->to_fin_sent = 1;
|
|
|
|
ev.events = 0;
|
|
ref.s = move_from;
|
|
ev.data.u64 = ref.u64,
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_MOD,
|
|
move_from, &ev);
|
|
}
|
|
|
|
if (conn->from_fin_sent)
|
|
goto close;
|
|
}
|
|
}
|
|
|
|
if ((events & (EPOLLIN | EPOLLOUT)) == (EPOLLIN | EPOLLOUT)) {
|
|
events = EPOLLIN;
|
|
|
|
SWAP(move_from, move_to);
|
|
if (pipes == conn->pipe_from_to)
|
|
pipes = conn->pipe_to_from;
|
|
else
|
|
pipes = conn->pipe_from_to;
|
|
|
|
goto swap;
|
|
}
|
|
|
|
return;
|
|
|
|
close:
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_DEL, conn->from, NULL);
|
|
epoll_ctl(c->epollfd, EPOLL_CTL_DEL, conn->to, NULL);
|
|
conn->state = CLOSED;
|
|
return;
|
|
}
|
|
|
|
/**
|
|
* tcp_sock_handler() - Handle new data from socket
|
|
* @c: Execution context
|
|
* @ref: epoll reference
|
|
* @events: epoll events bitmap
|
|
* @now: Current timestamp
|
|
*/
|
|
void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
|
|
struct timespec *now)
|
|
{
|
|
struct tcp_tap_conn *conn;
|
|
|
|
if (ref.tcp.splice) {
|
|
tcp_sock_handler_splice(c, ref, events);
|
|
return;
|
|
}
|
|
|
|
if (ref.tcp.listen) {
|
|
tcp_conn_from_sock(c, ref, now);
|
|
return;
|
|
}
|
|
|
|
conn = &tt[ref.tcp.index];
|
|
|
|
conn->ts_sock_act = *now;
|
|
|
|
if (events & EPOLLERR) {
|
|
if (conn->state != CLOSED)
|
|
tcp_rst(c, conn);
|
|
|
|
return;
|
|
}
|
|
|
|
switch (conn->state) {
|
|
case TAP_SYN_SENT:
|
|
if (events & EPOLLOUT)
|
|
tcp_connect_finish(c, conn, now);
|
|
else
|
|
tcp_rst(c, conn);
|
|
return;
|
|
case ESTABLISHED_SOCK_FIN:
|
|
case ESTABLISHED_SOCK_FIN_SENT:
|
|
case ESTABLISHED:
|
|
if (events & EPOLLRDHUP) {
|
|
if (conn->state == ESTABLISHED)
|
|
tcp_tap_state(conn, ESTABLISHED_SOCK_FIN);
|
|
}
|
|
tcp_data_from_sock(c, conn, now);
|
|
return;
|
|
case LAST_ACK:
|
|
tcp_send_to_tap(c, conn, 0, now);
|
|
if (conn->seq_ack_to_tap == conn->seq_from_tap + 1 ||
|
|
conn->seq_ack_to_tap == conn->seq_from_tap)
|
|
tcp_tap_destroy(c, conn);
|
|
return;
|
|
case FIN_WAIT_1:
|
|
if (events & EPOLLIN)
|
|
tcp_data_from_sock(c, conn, now);
|
|
if (events & EPOLLRDHUP) {
|
|
tcp_send_to_tap(c, conn, FIN | ACK, now);
|
|
tcp_tap_state(conn, FIN_WAIT_1_SOCK_FIN);
|
|
}
|
|
return;
|
|
case CLOSE_WAIT:
|
|
case FIN_WAIT_1_SOCK_FIN:
|
|
if (events & EPOLLIN)
|
|
tcp_data_from_sock(c, conn, now);
|
|
if (events & EPOLLHUP) {
|
|
if ((conn->seq_ack_to_tap == conn->seq_from_tap + 1 ||
|
|
conn->seq_ack_to_tap == conn->seq_from_tap) &&
|
|
(conn->seq_ack_from_tap == conn->seq_to_tap - 1 ||
|
|
conn->seq_ack_from_tap == conn->seq_to_tap)) {
|
|
tcp_tap_destroy(c, conn);
|
|
} else {
|
|
tcp_send_to_tap(c, conn, ACK, now);
|
|
}
|
|
}
|
|
return;
|
|
case TAP_SYN_RCVD:
|
|
case SOCK_SYN_SENT:
|
|
case SPLICE_ACCEPTED:
|
|
case SPLICE_CONNECT:
|
|
case SPLICE_ESTABLISHED:
|
|
case SPLICE_FIN_FROM:
|
|
case SPLICE_FIN_TO:
|
|
case SPLICE_FIN_BOTH:
|
|
case CLOSED:
|
|
break;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* tcp_set_pipe_size() - Set usable pipe size, probe starting from MAX_PIPE_SIZE
|
|
* @c: Execution context
|
|
*/
|
|
static void tcp_set_pipe_size(struct ctx *c)
|
|
{
|
|
int probe_pipe[TCP_SPLICE_PIPE_POOL_SIZE * 2][2], i, j;
|
|
|
|
c->tcp.pipe_size = MAX_PIPE_SIZE;
|
|
|
|
smaller:
|
|
for (i = 0; i < TCP_SPLICE_PIPE_POOL_SIZE * 2; i++) {
|
|
if (pipe(probe_pipe[i])) {
|
|
i++;
|
|
break;
|
|
}
|
|
|
|
if (fcntl(probe_pipe[i][0], F_SETPIPE_SZ, c->tcp.pipe_size) < 0)
|
|
break;
|
|
}
|
|
|
|
for (j = i - 1; j >= 0; j--) {
|
|
close(probe_pipe[j][0]);
|
|
close(probe_pipe[j][1]);
|
|
}
|
|
|
|
if (i == TCP_SPLICE_PIPE_POOL_SIZE * 2)
|
|
return;
|
|
|
|
if (!(c->tcp.pipe_size /= 2)) {
|
|
c->tcp.pipe_size = MAX_PIPE_SIZE;
|
|
return;
|
|
}
|
|
|
|
goto smaller;
|
|
}
|
|
|
|
/**
|
|
* tcp_sock_init_one() - Initialise listening sockets for a given port
|
|
* @c: Execution context
|
|
* @ns: In pasta mode, if set, bind with loopback address in namespace
|
|
* @port: Port, host order
|
|
*/
|
|
static void tcp_sock_init_one(struct ctx *c, int ns, in_port_t port)
|
|
{
|
|
union tcp_epoll_ref tref = { .listen = 1 };
|
|
int s;
|
|
|
|
if (ns)
|
|
tref.index = (in_port_t)(port + tcp_port_delta_to_init[port]);
|
|
else
|
|
tref.index = (in_port_t)(port + tcp_port_delta_to_tap[port]);
|
|
|
|
if (c->v4) {
|
|
tref.v6 = 0;
|
|
|
|
tref.splice = 0;
|
|
if (!ns) {
|
|
s = sock_l4(c, AF_INET, IPPROTO_TCP, port,
|
|
c->mode == MODE_PASTA ? BIND_EXT : BIND_ANY,
|
|
tref.u32);
|
|
if (s > 0)
|
|
tcp_sock_set_bufsize(c, s);
|
|
else
|
|
s = -1;
|
|
|
|
if (c->tcp.init_detect_ports)
|
|
tcp_sock_init_ext[port][V4] = s;
|
|
}
|
|
|
|
if (c->mode == MODE_PASTA) {
|
|
tref.splice = 1;
|
|
s = sock_l4(c, AF_INET, IPPROTO_TCP, port,
|
|
BIND_LOOPBACK, tref.u32);
|
|
if (s > 0)
|
|
tcp_sock_set_bufsize(c, s);
|
|
else
|
|
s = -1;
|
|
|
|
if (c->tcp.ns_detect_ports) {
|
|
if (ns)
|
|
tcp_sock_ns[port][V4] = s;
|
|
else
|
|
tcp_sock_init_lo[port][V4] = s;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (c->v6) {
|
|
tref.v6 = 1;
|
|
|
|
tref.splice = 0;
|
|
if (!ns) {
|
|
s = sock_l4(c, AF_INET6, IPPROTO_TCP, port,
|
|
c->mode == MODE_PASTA ? BIND_EXT : BIND_ANY,
|
|
tref.u32);
|
|
if (s > 0)
|
|
tcp_sock_set_bufsize(c, s);
|
|
else
|
|
s = -1;
|
|
|
|
if (c->tcp.init_detect_ports)
|
|
tcp_sock_init_ext[port][V6] = s;
|
|
}
|
|
|
|
if (c->mode == MODE_PASTA) {
|
|
tref.splice = 1;
|
|
s = sock_l4(c, AF_INET6, IPPROTO_TCP, port,
|
|
BIND_LOOPBACK, tref.u32);
|
|
if (s > 0)
|
|
tcp_sock_set_bufsize(c, s);
|
|
else
|
|
s = -1;
|
|
|
|
if (c->tcp.ns_detect_ports) {
|
|
if (ns)
|
|
tcp_sock_ns[port][V6] = s;
|
|
else
|
|
tcp_sock_init_lo[port][V6] = s;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* tcp_sock_init_ns() - Bind sockets in namespace for inbound connections
|
|
* @arg: Execution context
|
|
*
|
|
* Return: 0 on success, -1 on failure
|
|
*/
|
|
static int tcp_sock_init_ns(void *arg)
|
|
{
|
|
struct ctx *c = (struct ctx *)arg;
|
|
in_port_t port;
|
|
|
|
ns_enter(c);
|
|
|
|
for (port = 0; port < USHRT_MAX; port++) {
|
|
if (!bitmap_isset(c->tcp.port_to_init, port))
|
|
continue;
|
|
|
|
tcp_sock_init_one(c, 1, port);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tcp_splice_pipe_refill() - Refill pool of pre-opened pipes
|
|
* @c: Execution context
|
|
*/
|
|
static void tcp_splice_pipe_refill(struct ctx *c)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < TCP_SPLICE_PIPE_POOL_SIZE; i++) {
|
|
if (splice_pipe_pool[i][0][0] > 0)
|
|
break;
|
|
if (pipe2(splice_pipe_pool[i][0], O_NONBLOCK))
|
|
continue;
|
|
if (pipe2(splice_pipe_pool[i][1], O_NONBLOCK)) {
|
|
close(splice_pipe_pool[i][1][0]);
|
|
close(splice_pipe_pool[i][1][1]);
|
|
continue;
|
|
}
|
|
|
|
fcntl(splice_pipe_pool[i][0][0], F_SETPIPE_SZ,
|
|
c->tcp.pipe_size);
|
|
fcntl(splice_pipe_pool[i][1][0], F_SETPIPE_SZ,
|
|
c->tcp.pipe_size);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* struct tcp_sock_refill_arg - Arguments for tcp_sock_refill()
|
|
* @c: Execution context
|
|
* @ns: Set to refill pool of sockets created in namespace
|
|
*/
|
|
struct tcp_sock_refill_arg {
|
|
struct ctx *c;
|
|
int ns;
|
|
};
|
|
|
|
/**
|
|
* tcp_sock_refill() - Refill pool of pre-opened sockets
|
|
* @arg: See @tcp_sock_refill_arg
|
|
*
|
|
* Return: 0
|
|
*/
|
|
static int tcp_sock_refill(void *arg)
|
|
{
|
|
struct tcp_sock_refill_arg *a = (struct tcp_sock_refill_arg *)arg;
|
|
int i, *p4, *p6;
|
|
|
|
if (a->ns) {
|
|
if (ns_enter(a->c))
|
|
return 0;
|
|
p4 = ns_sock_pool4;
|
|
p6 = ns_sock_pool6;
|
|
} else {
|
|
p4 = init_sock_pool4;
|
|
p6 = init_sock_pool6;
|
|
}
|
|
|
|
for (i = 0; a->c->v4 && i < TCP_SOCK_POOL_SIZE; i++, p4++) {
|
|
if (*p4 > 0) {
|
|
break;
|
|
}
|
|
*p4 = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
|
|
tcp_sock_set_bufsize(a->c, *p4);
|
|
}
|
|
|
|
for (i = 0; a->c->v6 && i < TCP_SOCK_POOL_SIZE; i++, p6++) {
|
|
if (*p6 > 0) {
|
|
break;
|
|
}
|
|
*p6 = socket(AF_INET6, SOCK_STREAM | SOCK_NONBLOCK,
|
|
IPPROTO_TCP);
|
|
tcp_sock_set_bufsize(a->c, *p6);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tcp_sock_init() - Bind sockets for inbound connections, get key for sequence
|
|
* @c: Execution context
|
|
*
|
|
* Return: 0 on success, -1 on failure
|
|
*/
|
|
int tcp_sock_init(struct ctx *c, struct timespec *now)
|
|
{
|
|
struct tcp_sock_refill_arg refill_arg = { c, 0 };
|
|
in_port_t port;
|
|
int i;
|
|
|
|
getrandom(&c->tcp.hash_secret, sizeof(c->tcp.hash_secret), GRND_RANDOM);
|
|
|
|
for (port = 0; port < USHRT_MAX; port++) {
|
|
if (!bitmap_isset(c->tcp.port_to_tap, port))
|
|
continue;
|
|
|
|
tcp_sock_init_one(c, 0, port);
|
|
}
|
|
|
|
for (i = 0; i < ARRAY_SIZE(tcp_l2_mh_tap); i++)
|
|
tcp_l2_mh_tap[i] = (struct mmsghdr) { .msg_hdr.msg_iovlen = 1 };
|
|
|
|
if (c->v4)
|
|
tcp_sock4_iov_init();
|
|
|
|
if (c->v6)
|
|
tcp_sock6_iov_init();
|
|
|
|
c->tcp.refill_ts = *now;
|
|
tcp_sock_refill(&refill_arg);
|
|
|
|
if (c->mode == MODE_PASTA) {
|
|
tcp_set_pipe_size(c);
|
|
NS_CALL(tcp_sock_init_ns, c);
|
|
|
|
refill_arg.ns = 1;
|
|
NS_CALL(tcp_sock_refill, &refill_arg);
|
|
tcp_splice_pipe_refill(c);
|
|
|
|
c->tcp.port_detect_ts = *now;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tcp_timer_one() - Handler for timed events on one socket
|
|
* @c: Execution context
|
|
* @conn: Connection pointer
|
|
* @ts: Timestamp from caller
|
|
*/
|
|
static void tcp_timer_one(struct ctx *c, struct tcp_tap_conn *conn,
|
|
struct timespec *ts)
|
|
{
|
|
int ack_from_tap = timespec_diff_ms(ts, &conn->ts_ack_from_tap);
|
|
int ack_to_tap = timespec_diff_ms(ts, &conn->ts_ack_to_tap);
|
|
int sock_act = timespec_diff_ms(ts, &conn->ts_sock_act);
|
|
int tap_act = timespec_diff_ms(ts, &conn->ts_tap_act);
|
|
int tap_data_noack;
|
|
|
|
if (!memcmp(&conn->tap_data_noack, &((struct timespec){ 0, 0 }),
|
|
sizeof(struct timespec)))
|
|
tap_data_noack = 0;
|
|
else
|
|
tap_data_noack = timespec_diff_ms(ts, &conn->tap_data_noack);
|
|
|
|
switch (conn->state) {
|
|
case CLOSED:
|
|
tcp_hash_remove(conn);
|
|
tcp_table_tap_compact(c, conn);
|
|
break;
|
|
case SOCK_SYN_SENT:
|
|
case TAP_SYN_RCVD:
|
|
if (ack_from_tap > SYN_TIMEOUT)
|
|
tcp_rst(c, conn);
|
|
|
|
break;
|
|
case ESTABLISHED_SOCK_FIN_SENT:
|
|
if (tap_data_noack > FIN_TIMEOUT) {
|
|
tcp_rst(c, conn);
|
|
break;
|
|
}
|
|
/* Falls through */
|
|
case ESTABLISHED:
|
|
case ESTABLISHED_SOCK_FIN:
|
|
if (tap_act > ACT_TIMEOUT && sock_act > ACT_TIMEOUT) {
|
|
tcp_rst(c, conn);
|
|
break;
|
|
}
|
|
|
|
if (!conn->wnd_to_tap)
|
|
tcp_send_to_tap(c, conn, 0, ts);
|
|
else if (ack_to_tap > ACK_INTERVAL)
|
|
tcp_send_to_tap(c, conn, 0, ts);
|
|
|
|
if (tap_data_noack > ACK_TIMEOUT) {
|
|
if (conn->seq_ack_from_tap < conn->seq_to_tap) {
|
|
if (tap_data_noack > LAST_ACK_TIMEOUT) {
|
|
tcp_rst(c, conn);
|
|
break;
|
|
}
|
|
|
|
conn->seq_to_tap = conn->seq_ack_from_tap;
|
|
tcp_data_from_sock(c, conn, ts);
|
|
}
|
|
}
|
|
break;
|
|
case CLOSE_WAIT:
|
|
case FIN_WAIT_1_SOCK_FIN:
|
|
if (tap_data_noack > FIN_TIMEOUT)
|
|
tcp_rst(c, conn);
|
|
break;
|
|
case FIN_WAIT_1:
|
|
if (sock_act > FIN_TIMEOUT)
|
|
tcp_rst(c, conn);
|
|
break;
|
|
case LAST_ACK:
|
|
if (sock_act > LAST_ACK_TIMEOUT)
|
|
tcp_rst(c, conn);
|
|
else if (tap_act > LAST_ACK_TIMEOUT)
|
|
tcp_rst(c, conn);
|
|
break;
|
|
case TAP_SYN_SENT:
|
|
case SPLICE_ACCEPTED:
|
|
case SPLICE_CONNECT:
|
|
case SPLICE_ESTABLISHED:
|
|
case SPLICE_FIN_FROM:
|
|
case SPLICE_FIN_TO:
|
|
case SPLICE_FIN_BOTH:
|
|
break;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* struct tcp_port_detect_arg - Arguments for tcp_port_detect()
|
|
* @c: Execution context
|
|
* @detect_in_ns: Detect ports bound in namespace, not in init
|
|
*/
|
|
struct tcp_port_detect_arg {
|
|
struct ctx *c;
|
|
int detect_in_ns;
|
|
};
|
|
|
|
/**
|
|
* tcp_port_detect() - Detect ports bound in namespace or init
|
|
* @arg: See struct tcp_port_detect_arg
|
|
*
|
|
* Return: 0
|
|
*/
|
|
static int tcp_port_detect(void *arg)
|
|
{
|
|
struct tcp_port_detect_arg *a = (struct tcp_port_detect_arg *)arg;
|
|
|
|
if (a->detect_in_ns) {
|
|
ns_enter(a->c);
|
|
|
|
get_bound_ports(a->c, 1, IPPROTO_TCP);
|
|
} else {
|
|
get_bound_ports(a->c, 0, IPPROTO_TCP);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* struct tcp_port_rebind_arg - Arguments for tcp_port_rebind()
|
|
* @c: Execution context
|
|
* @bind_in_ns: Rebind ports in namespace, not in init
|
|
*/
|
|
struct tcp_port_rebind_arg {
|
|
struct ctx *c;
|
|
int bind_in_ns;
|
|
};
|
|
|
|
/**
|
|
* tcp_port_rebind() - Rebind ports in namespace or init
|
|
* @arg: See struct tcp_port_rebind_arg
|
|
*
|
|
* Return: 0
|
|
*/
|
|
static int tcp_port_rebind(void *arg)
|
|
{
|
|
struct tcp_port_rebind_arg *a = (struct tcp_port_rebind_arg *)arg;
|
|
in_port_t port;
|
|
|
|
if (a->bind_in_ns) {
|
|
ns_enter(a->c);
|
|
|
|
for (port = 0; port < USHRT_MAX; port++) {
|
|
if (!bitmap_isset(a->c->tcp.port_to_init, port)) {
|
|
if (tcp_sock_ns[port][V4] > 0) {
|
|
close(tcp_sock_ns[port][V4]);
|
|
tcp_sock_ns[port][V4] = 0;
|
|
}
|
|
|
|
if (tcp_sock_ns[port][V6] > 0) {
|
|
close(tcp_sock_ns[port][V6]);
|
|
tcp_sock_ns[port][V6] = 0;
|
|
}
|
|
|
|
continue;
|
|
}
|
|
|
|
/* Don't loop back our own ports */
|
|
if (bitmap_isset(a->c->tcp.port_to_tap, port))
|
|
continue;
|
|
|
|
if ((a->c->v4 && !tcp_sock_ns[port][V4]) ||
|
|
(a->c->v6 && !tcp_sock_ns[port][V6]))
|
|
tcp_sock_init_one(a->c, 1, port);
|
|
}
|
|
} else {
|
|
for (port = 0; port < USHRT_MAX; port++) {
|
|
if (!bitmap_isset(a->c->tcp.port_to_tap, port)) {
|
|
if (tcp_sock_init_ext[port][V4] > 0) {
|
|
close(tcp_sock_init_ext[port][V4]);
|
|
tcp_sock_init_ext[port][V4] = 0;
|
|
}
|
|
|
|
if (tcp_sock_init_ext[port][V6] > 0) {
|
|
close(tcp_sock_init_ext[port][V6]);
|
|
tcp_sock_init_ext[port][V6] = 0;
|
|
}
|
|
|
|
if (tcp_sock_init_lo[port][V4] > 0) {
|
|
close(tcp_sock_init_lo[port][V4]);
|
|
tcp_sock_init_lo[port][V4] = 0;
|
|
}
|
|
|
|
if (tcp_sock_init_lo[port][V6] > 0) {
|
|
close(tcp_sock_init_lo[port][V6]);
|
|
tcp_sock_init_lo[port][V6] = 0;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
/* Don't loop back our own ports */
|
|
if (bitmap_isset(a->c->tcp.port_to_init, port))
|
|
continue;
|
|
|
|
if ((a->c->v4 && !tcp_sock_init_ext[port][V4]) ||
|
|
(a->c->v6 && !tcp_sock_init_ext[port][V6]))
|
|
tcp_sock_init_one(a->c, 0, port);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tcp_timer() - Scan activity bitmap for sockets waiting for timed events
|
|
* @c: Execution context
|
|
* @ts: Timestamp from caller
|
|
*/
|
|
void tcp_timer(struct ctx *c, struct timespec *now)
|
|
{
|
|
struct tcp_sock_refill_arg refill_arg = { c, 0 };
|
|
int i;
|
|
|
|
if (c->mode == MODE_PASTA) {
|
|
if (timespec_diff_ms(now, &c->tcp.port_detect_ts) >
|
|
PORT_DETECT_INTERVAL) {
|
|
struct tcp_port_detect_arg detect_arg = { c, 0 };
|
|
struct tcp_port_rebind_arg rebind_arg = { c, 0 };
|
|
|
|
if (c->tcp.init_detect_ports) {
|
|
detect_arg.detect_in_ns = 0;
|
|
tcp_port_detect(&detect_arg);
|
|
rebind_arg.bind_in_ns = 1;
|
|
NS_CALL(tcp_port_rebind, &rebind_arg);
|
|
}
|
|
|
|
if (c->tcp.ns_detect_ports) {
|
|
detect_arg.detect_in_ns = 1;
|
|
NS_CALL(tcp_port_detect, &detect_arg);
|
|
rebind_arg.bind_in_ns = 0;
|
|
tcp_port_rebind(&rebind_arg);
|
|
}
|
|
|
|
c->tcp.port_detect_ts = *now;
|
|
}
|
|
}
|
|
|
|
if (timespec_diff_ms(now, &c->tcp.refill_ts) > REFILL_INTERVAL) {
|
|
tcp_sock_refill(&refill_arg);
|
|
if (c->mode == MODE_PASTA) {
|
|
refill_arg.ns = 1;
|
|
if ((c->v4 && ns_sock_pool4[TCP_SOCK_POOL_TSH] <= 0) ||
|
|
(c->v6 && ns_sock_pool6[TCP_SOCK_POOL_TSH] <= 0))
|
|
NS_CALL(tcp_sock_refill, &refill_arg);
|
|
|
|
tcp_splice_pipe_refill(c);
|
|
}
|
|
}
|
|
|
|
for (i = c->tcp.tap_conn_count - 1; i >= 0; i--)
|
|
tcp_timer_one(c, tt + i, now);
|
|
|
|
if (c->mode == MODE_PASTA) {
|
|
for (i = c->tcp.splice_conn_count - 1; i >= 0; i--) {
|
|
if ((ts + i)->state == CLOSED) {
|
|
tcp_splice_destroy(c, ts + i);
|
|
continue;
|
|
}
|
|
|
|
if (bitmap_isset(splice_rcvlowat_set[0], i) &&
|
|
!bitmap_isset(splice_rcvlowat_act[0], i)) {
|
|
int lowat = 1;
|
|
|
|
setsockopt((ts + i)->from, SOL_SOCKET,
|
|
SO_RCVLOWAT, &lowat, sizeof(lowat));
|
|
bitmap_clear(splice_rcvlowat_set[0], i);
|
|
}
|
|
|
|
if (bitmap_isset(splice_rcvlowat_set[1], i) &&
|
|
!bitmap_isset(splice_rcvlowat_act[1], i)) {
|
|
int lowat = 1;
|
|
|
|
setsockopt((ts + i)->to, SOL_SOCKET,
|
|
SO_RCVLOWAT, &lowat, sizeof(lowat));
|
|
bitmap_clear(splice_rcvlowat_set[1], i);
|
|
}
|
|
|
|
bitmap_clear(splice_rcvlowat_act[0], i);
|
|
bitmap_clear(splice_rcvlowat_act[1], i);
|
|
}
|
|
}
|
|
}
|