passt/icmp.c, branch 2026_05_07.1afd4ed

treewide: Spell ASSERT() as assert()

2026-03-20T20:05:29+00:00

The standard library assert(3), at least with glibc, hits our seccomp
filter and dies with SIGSYS before it's able to print a message, making it
near useless.  Therefore, since 7a8ed9459dfe ("Make assertions actually
useful") we've instead used our own implementation, named ASSERT().

This makes our code look slightly odd though - ASSERT() has the same
overall effect as assert(), it's just a different implementation.  More
importantly this makes it awkward to share code between passt/pasta proper
and things that compile in a more typical environment.  We're going to want
that for our upcoming dynamic configuration tool.

Address this by overriding the standard library's assert() implementation
with our own, instead of giving ours its own name.

The standard assert() is supposed to be omitted if NDEBUG is defined,
which ours doesn't do.  Implement that as well, so ours doesn't
unexpectedly differ.  For the -DNDEBUG case we do this by *not* overriding
assert(), since it will be a no-op anyway.  This requires a few places to
add a #include  to let us compile (albeit with warnings) when
-DNDEBUG.

Signed-off-by: David Gibson 
[sbrivio: Fix some conflicts and missing conversions as a result of
 applying "vu_common: Move iovec management into vu_collect()" first]
Signed-off-by: Stefano Brivio

flow: Remove EPOLLFD_ID_INVALID

2026-01-20T18:37:53+00:00

As all flows are now registered with an epollid at creation, we no
longer need to test if a flow is in epoll.  Remove all related code
including flow_in_epoll() and flow_epollid_clear().

Signed-off-by: Laurent Vivier 
Reviewed-by: David Gibson 
Signed-off-by: Stefano Brivio

flow, fwd: Optimise forwarding rule lookup using epoll ref when possible

2026-01-18T11:48:09+00:00

Now that listening sockets include a reference to the forwarding rule
which created them we can, in many cases, avoid a linear search of the
forwarding table when we want to find the relevant rule.  Instead we
can take the rule index from the socket's epoll reference, and use
that to immediately find the correct rule.

This is conceptually simple, but requires a moderate amount of
plumbing to get the index from the reference through to the rule
lookup.  We still allow fall back to linear search if we don't have
the index, and this may (rarely) be used in the udp_flush_flow() case,
where we could get packets for one flow on a different flow's socket,
rather than through a listening socket as usual.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio

flow: Introduce flow_epoll_set() to centralize epoll operations

2026-01-14T00:07:51+00:00

Currently, each flow type (TCP, TCP_SPLICE, PING, UDP) has its own
code to add or modify file descriptors in epoll. This leads to
duplicated boilerplate code across icmp.c, tcp.c, tcp_splice.c, and
udp_flow.c, each setting up epoll_ref unions and calling epoll_ctl()
with flow-type-specific details.

Introduce flow_epoll_set() in flow.c to handle epoll operations for
all flow types in a unified way.

This will be needed to migrate queue pair from an epollfd to another.

Signed-off-by: Laurent Vivier 
Reviewed-by: David Gibson 
Signed-off-by: Stefano Brivio

inany: Let length of sockaddr_inany be implicit from the family

2025-12-02T22:07:14+00:00

sockaddr_inany can contain either an IPv4 or IPv6 socket address, so the
relevant length for bind() or connect() can vary.  In pif_sockaddr() we
return that length, and in sock_l4_sa() we take it as an extra parameter.

However, sockaddr_inany always contains exactly a sockaddr_in or a
sockaddr_in6 each with a fixed size.  Therefore we can derive the relevant
length from the family, and don't need to pass it around separately.

Make a tiny helper to get the relevant address length, and update all
interfaces to use that approach instead.

In the process, fix a buglet in tcp_flow_repair_bind(): we passed
sizeof(union sockaddr_inany) to bind() instead of the specific length for
the address family.  Since the sizeof() is always longer than the specific
length, this is probably fine, but not theoretically correct.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio

icmp: Use epoll instance management for ICMP flows

2025-10-30T14:33:03+00:00

Store the epoll id in the flow_common structure for ICMP ping flows
using flow_epollid_set() and retrieve the corresponding epoll
file descriptor with flow_epollfd() instead of passing c->epollfd
directly. This makes ICMP consistent with the recent TCP changes and
follows the pattern established in previous commit.

Signed-off-by: Laurent Vivier 
Reviewed-by: David Gibson 
Signed-off-by: Stefano Brivio

util: Move epoll registration out of sock_l4_sa()

2025-10-30T14:32:30+00:00

Move epoll_add() calls from sock_l4_sa() to the protocol-specific code
(icmp.c, pif.c, udp_flow.c) to give callers more control over epoll
registration. This allows sock_l4_sa() to focus solely on socket
creation and binding, while epoll management happens at a higher level.

Remove the data parameter from sock_l4_sa() and flowside_sock_l4() as
it's no longer needed - callers now construct the full epoll_ref and
register the socket themselves after creation.

Signed-off-by: Laurent Vivier 
Reviewed-by: David Gibson 
Signed-off-by: Stefano Brivio

epoll_ctl: Extract epoll operations

2025-10-30T14:32:12+00:00

Centralize epoll_add() and epoll_del() helper functions into new
epoll_ctl.c/h files.

This also moves the union epoll_ref definition from passt.h to
epoll_ctl.h where it's more logically placed.

The new epoll_add() helper simplifies adding file descriptors to epoll
by taking an epoll_ref and events, handling error reporting
consistently across all call sites.

Signed-off-by: Laurent Vivier 
[sbrivio: Include epoll_ctl.h from netlink.c as it's now needed there]
Reviewed-by: David Gibson 
Signed-off-by: Stefano Brivio

util: Simplify epoll_del() interface to take epollfd directly

2025-10-30T14:32:03+00:00

Change epoll_del() to accept the epoll file descriptor directly instead
of the full context structure. This simplifies the interface and aligns
with the threading refactoring by reducing dependency on the context
structure for basic epoll operations as we will manage an epollfd per
thread.

Signed-off-by: Laurent Vivier 
Reviewed-by: David Gibson 
Signed-off-by: Stefano Brivio

icmp: let icmp use mac address from flowside structure

2025-10-30T11:01:01+00:00

Even ICMP needs to be updated to use the external MAC address instead
of just the own tap address when applicable. We do that here.

Signed-off-by: Jon Maloy 
Reviewed-by: David Gibson 
Signed-off-by: Stefano Brivio