Commit graph

11 commits

Author SHA1 Message Date
Stefano Brivio
dd942eaa48 passt: Fix build with gcc 7, use std=c99, enable some more Clang checkers
Unions and structs, you all have names now.

Take the chance to enable bugprone-reserved-identifier,
cert-dcl37-c, and cert-dcl51-cpp checkers in clang-tidy.

Provide a ffsl() weak declaration using gcc built-in.

Start reordering includes, but that's not enough for the
llvm-include-order checker yet.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-21 04:26:08 +02:00
Stefano Brivio
1a563a0cbd passt: Address gcc 11 warnings
A mix of unchecked return values, a missing permission mask for
open(2) with O_CREAT, and some false positives from
-Wstringop-overflow and -Wmaybe-uninitialized.

Reported-by: Martin Hauke <mardnh@gmx.de>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-20 08:29:30 +02:00
Giuseppe Scrivano
9a175cc2ce pasta: Allow specifying paths and names of namespaces
Based on a patch from Giuseppe Scrivano, this adds the ability to:

- specify paths and names of target namespaces to join, instead of
  a PID, also for user namespaces, with --userns

- request to join or create a network namespace only, without
  entering or creating a user namespace, with --netns-only

- specify the base directory for netns mountpoints, with --nsrun-dir

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
[sbrivio: reworked logic to actually join the given namespaces when
 they're not created, implemented --netns-only and --nsrun-dir,
 updated pasta demo script and man page]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-07 04:05:15 +02:00
Stefano Brivio
a491c8ee3c pcap: Drop O_DSYNC from pcap file descriptor
passt is stable enough, and dropping O_DSYNC makes reduces the impact
of capturing packets on timing, while running tests.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-09-27 01:28:02 +02:00
Stefano Brivio
11cc43feec pcap: Don't make pcap files world-readable
Even if it's just a debugging feature, it's not nice to leak packets
to everybody around.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-09-27 01:28:02 +02:00
Stefano Brivio
e4b94da0af pcap: Don't reinitialise packet capture if we already have one
If the guest disconnects, and a given name (without timestamp) for
the pcap file is passed, we would otherwise lose the packets
captured until that point.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-09-27 01:28:02 +02:00
Stefano Brivio
1e49d194d0 passt, pasta: Introduce command-line options and port re-mapping
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-09-01 17:00:27 +02:00
Stefano Brivio
64a0ba3b27 udp: Introduce recvmmsg()/sendmmsg(), zero-copy path from socket
Packets are received directly onto pre-cooked, static buffers
for IPv4 (with partial checksum pre-calculation) and IPv6 frames,
with pre-filled Ethernet addresses and, partially, IP headers,
and sent out from the same buffers with sendmmsg(), for both
passt and pasta (non-local traffic only) modes.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-07-21 12:01:04 +02:00
Stefano Brivio
33482d5bf2 passt: Add PASTA mode, major rework
PASTA (Pack A Subtle Tap Abstraction) provides quasi-native host
connectivity to an otherwise disconnected, unprivileged network
and user namespace, similarly to slirp4netns. Given that the
implementation is largely overlapping with PASST, no separate binary
is built: 'pasta' (and 'passt4netns' for clarity) both link to
'passt', and the mode of operation is selected depending on how the
binary is invoked. Usage example:

	$ unshare -rUn
	# echo $$
	1871759

	$ ./pasta 1871759	# From another terminal

	# udhcpc -i pasta0 2>/dev/null
	# ping -c1 pasta.pizza
	PING pasta.pizza (64.190.62.111) 56(84) bytes of data.
	64 bytes from 64.190.62.111 (64.190.62.111): icmp_seq=1 ttl=255 time=34.6 ms

	--- pasta.pizza ping statistics ---
	1 packets transmitted, 1 received, 0% packet loss, time 0ms
	rtt min/avg/max/mdev = 34.575/34.575/34.575/0.000 ms
	# ping -c1 spaghetti.pizza
	PING spaghetti.pizza(2606:4700:3034::6815:147a (2606:4700:3034::6815:147a)) 56 data bytes
	64 bytes from 2606:4700:3034::6815:147a (2606:4700:3034::6815:147a): icmp_seq=1 ttl=255 time=29.0 ms

	--- spaghetti.pizza ping statistics ---
	1 packets transmitted, 1 received, 0% packet loss, time 0ms
	rtt min/avg/max/mdev = 28.967/28.967/28.967/0.000 ms

This entails a major rework, especially with regard to the storage of
tracked connections and to the semantics of epoll(7) references.

Indexing TCP and UDP bindings merely by socket proved to be
inflexible and unsuitable to handle different connection flows: pasta
also provides Layer-2 to Layer-2 socket mapping between init and a
separate namespace for local connections, using a pair of splice()
system calls for TCP, and a recvmmsg()/sendmmsg() pair for UDP local
bindings. For instance, building on the previous example:

	# ip link set dev lo up
	# iperf3 -s

	$ iperf3 -c ::1 -Z -w 32M -l 1024k -P2 | tail -n4
	[SUM]   0.00-10.00  sec  52.3 GBytes  44.9 Gbits/sec  283             sender
	[SUM]   0.00-10.43  sec  52.3 GBytes  43.1 Gbits/sec                  receiver

	iperf Done.

epoll(7) references now include a generic part in order to
demultiplex data to the relevant protocol handler, using 24
bits for the socket number, and an opaque portion reserved for
usage by the single protocol handlers, in order to track sockets
back to corresponding connections and bindings.

A number of fixes pertaining to TCP state machine and congestion
window handling are also included here.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-07-17 11:04:22 +02:00
Stefano Brivio
19d254bbbb passt: Add support for multiple instances in different network namespaces
...sharing the same filesystem. Instead of a fixed path for the UNIX
domain socket, passt now uses a path with a counter, probing for
existing instances, and picking the first free one.

The demo script is updated accordingly -- it can now be started several
times to create multiple namespaces with an instance of passt each,
with addressing reflecting separate subnets, and NDP proxying between
them.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-05-21 11:14:51 +02:00
Stefano Brivio
17337a736f passt: Introduce packet capture implementation
With -DDEBUG, passt now saves guest-side traffic captures in
pcap format at /tmp/passt_<ISO8601 timestamp>.pcap. The timestamp
refers to time and date of start-up.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-05-21 11:14:48 +02:00