On Thu, 13 Nov 2025 12:34:13 +1100
David Gibson
The --freebind option allows pasta to listen on addresses that aren't registered on the host, which has a number of use cases. However, we omitted this option for UDP "flow sockets" which are created once a flow is started, connect()ed specifically to the peer. Flow sockets are also bound, and if the peer has contacted a freebind address, we need IP_FREEBIND to do so.
Link: https://bugs.passt.top/show_bug.cgi?id=174
Signed-off-by: David Gibson
Applied.
--- util.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
I'm still waiting on confirmation from the reporter that this actually fixes bug 174. However, I'm pretty sure this is _a_ correct fix, whether or not it's a complete fix for the issue seen by the reporter.
From https://bugs.passt.top/show_bug.cgi?id=174#c0: I can't downgrade passt/pasta to an earlier version or test patches in my current setup ...so I guess we'll have to guess...
diff --git a/util.c b/util.c index 44c21a3e..ab23463b 100644 --- a/util.c +++ b/util.c @@ -67,9 +67,8 @@ int sock_l4_sa(const struct ctx *c, enum epoll_type type, freebind = c->freebind; break; case EPOLL_TYPE_UDP_LISTEN: - freebind = c->freebind; - /* fallthrough */ case EPOLL_TYPE_UDP: + freebind = c->freebind; proto = IPPROTO_UDP; socktype = SOCK_DGRAM | SOCK_NONBLOCK; break;
-- Stefano