Re: [PATCH 3/3] tcp, udp: Make {tcp,udp}_listen() return socket fds

On Sun, Jan 11, 2026 at 12:33:39AM +0100, Stefano Brivio wrote:

On Mon, 5 Jan 2026 19:28:50 +1100 David Gibson wrote:

...

{tcp,udp}_listen() currently return 0 on success, rather than the socket fd they created. Historically, that was because these functions could sometimes create multiple sockets. We've now refactored things to avoid that, so it makes more sense for them to return the socket on success.

Signed-off-by: David Gibson --- conf.c | 14 +++++++------- tcp.c | 7 ++----- udp.c | 4 ++-- 3 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/conf.c b/conf.c index cc3c20a9..5db49653 100644 --- a/conf.c +++ b/conf.c @@ -149,7 +149,7 @@ static void conf_ports_range_except(const struct ctx *c, char optname, { bool bound_one = false; unsigned i; - int ret; + int fd;

if (first == 0) { die("Can't forward port 0 for option '-%c %s'", @@ -185,23 +185,23 @@ static void conf_ports_range_except(const struct ctx *c, char optname, fwd->delta[i] = to - first;

if (optname == 't') - ret = tcp_listen(c, PIF_HOST, addr, ifname, i); + fd = tcp_listen(c, PIF_HOST, addr, ifname, i); else if (optname == 'u') - ret = udp_listen(c, PIF_HOST, addr, ifname, i); + fd = udp_listen(c, PIF_HOST, addr, ifname, i); else /* No way to check in advance for -T and -U */ - ret = 0; + fd = 0;

- if (ret == -ENFILE || ret == -EMFILE) { + if (fd == -ENFILE || fd == -EMFILE) { die("Can't open enough sockets for port specifier: %s", optarg); }

- if (!ret) { + if (fd >= 0) { bound_one = true; } else if (!weak) { die("Failed to bind port %u (%s) for option '-%c %s'", - i, strerror_(-ret), optname, optarg); + i, strerror_(-fd), optname, optarg); } }

diff --git a/tcp.c b/tcp.c index 67007c05..80b47f3c 100644 --- a/tcp.c +++ b/tcp.c @@ -2680,7 +2680,7 @@ void tcp_sock_handler(const struct ctx *c, union epoll_ref ref, * @ifname: Name of interface to bind to, NULL for any * @port: Port, host order * - * Return: 0 on success, negative error code on failure + * Return: Socket fd on success, negative error code on failure

Nit, here and on udp_listen(): "socket". See also 9e0423e13541 ("style: Fix 'Return' comment style").

Oops, fixed. -- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson