8d503e825f
Currently we have special sockets for receiving datagrams from locahost which can use the optimized "splice" path rather than going across the tap interface. We want to loosen this so that sockets can receive sockets that will be forwarded by both the spliced and non-spliced paths. To do this, we alter the meaning of the @splice bit in the reference to mean that packets receieved on this socket *can* be spliced, not that they *will* be spliced. They'll only actually be spliced if they come from 127.0.0.1 or ::1. We can't (for now) remove the splice bit entirely, unlike with TCP. Our gateway mapping means that if the ns initiates communication to the gw address, we'll translate that to target 127.0.0.1 on the host side. Reply packets will therefore have source address 127.0.0.1 when received on the host, but these need to go via the tap path where that will be translated back to the gateway address. We need the @splice bit to distinguish that case from packets going from localhost to a port mapped explicitly with -u which should be spliced. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
66 lines
2 KiB
C
66 lines
2 KiB
C
/* SPDX-License-Identifier: AGPL-3.0-or-later
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* Copyright (c) 2021 Red Hat GmbH
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* Author: Stefano Brivio <sbrivio@redhat.com>
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*/
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#ifndef UDP_H
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#define UDP_H
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#define UDP_TIMER_INTERVAL 1000 /* ms */
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void udp_sock_handler(const struct ctx *c, union epoll_ref ref, uint32_t events,
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const struct timespec *now);
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int udp_tap_handler(struct ctx *c, int af, const void *addr,
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const struct pool *p, const struct timespec *now);
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void udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
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const void *addr, const char *ifname, in_port_t port);
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int udp_init(struct ctx *c);
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void udp_timer(struct ctx *c, const struct timespec *ts);
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void udp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s,
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const struct in_addr *ip_da);
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/**
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* union udp_epoll_ref - epoll reference portion for TCP connections
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* @bound: Set if this file descriptor is a bound socket
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* @splice: Set if descriptor packets to be "spliced"
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* @orig: Set if a spliced socket which can originate "connections"
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* @ns: Set if this is a socket in the pasta network namespace
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* @v6: Set for IPv6 sockets or connections
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* @port: Source port for connected sockets, bound port otherwise
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* @u32: Opaque u32 value of reference
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*/
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union udp_epoll_ref {
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struct {
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bool splice:1,
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orig:1,
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ns:1,
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v6:1;
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uint32_t port:16;
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} udp;
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uint32_t u32;
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};
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/**
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* udp_port_fwd - UDP specific port forwarding configuration
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* @f: Generic forwarding configuration
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* @rdelta: Reversed delta map to translate source ports on return packets
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*/
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struct udp_port_fwd {
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struct port_fwd f;
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in_port_t rdelta[NUM_PORTS];
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};
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/**
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* struct udp_ctx - Execution context for UDP
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* @fwd_in: Port forwarding configuration for inbound packets
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* @fwd_out: Port forwarding configuration for outbound packets
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* @timer_run: Timestamp of most recent timer run
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*/
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struct udp_ctx {
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struct udp_port_fwd fwd_in;
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struct udp_port_fwd fwd_out;
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struct timespec timer_run;
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};
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#endif /* UDP_H */
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