sock_probe_mem() currently checks whether we're able to allocate large socket buffers. Extend it to also check whether the SO_BINDTODEVICE socket option is available. Rename to sock_probe_features() to reflect the new functionality. Signed-off-by: David Gibson --- passt.c | 2 +- passt.h | 1 + util.c | 19 +++++++++++++++++-- util.h | 2 +- 4 files changed, 20 insertions(+), 4 deletions(-) diff --git a/passt.c b/passt.c index 4964427d..0b84ac6c 100644 --- a/passt.c +++ b/passt.c @@ -381,7 +381,7 @@ int main(int argc, char **argv) if (setrlimit(RLIMIT_NOFILE, &limit)) die_perror("Failed to set current limit for open files"); - sock_probe_mem(&c); + sock_probe_features(&c); conf(&c, argc, argv); trace_init(c.trace); diff --git a/passt.h b/passt.h index 15801b44..e7c1710a 100644 --- a/passt.h +++ b/passt.h @@ -281,6 +281,7 @@ struct ctx { int low_wmem; int low_rmem; + int no_bindtodevice; struct vu_dev *vdev; diff --git a/util.c b/util.c index 347f34f5..bad38129 100644 --- a/util.c +++ b/util.c @@ -233,12 +233,13 @@ int sock_unix(char *sock_path) } /** - * sock_probe_mem() - Check if setting high SO_SNDBUF and SO_RCVBUF is allowed + * sock_probe_features() - Probe for socket features we might use * @c: Execution context */ -void sock_probe_mem(struct ctx *c) +void sock_probe_features(struct ctx *c) { int v = INT_MAX / 2, s; + const char lo[] = "lo"; socklen_t sl; s = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_TCP); @@ -247,6 +248,7 @@ void sock_probe_mem(struct ctx *c) return; } + /* Check if setting high SO_SNDBUF and SO_RCVBUF is allowed */ sl = sizeof(v); if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &v, sizeof(v)) || getsockopt(s, SOL_SOCKET, SO_SNDBUF, &v, &sl) || @@ -259,6 +261,19 @@ void sock_probe_mem(struct ctx *c) (size_t)v < RCVBUF_BIG) c->low_rmem = 1; + /* Check if SO_BINDTODEVICE is available + * + * Supported since kernel version 5.7, commit c427bfec18f2 ("net: core: + * enable SO_BINDTODEVICE for non-root users"). Some distro kernels may + * have backports, of course. Record whether we can use it so that we + * can give more useful diagnostics. + */ + if (setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, lo, sizeof(lo)-1)) { + if (errno != EPERM) + warn_perror("Unexpected error probing SO_BINDTODEVICE"); + c->no_bindtodevice = 1; + } + close(s); } diff --git a/util.h b/util.h index a0b2ada6..200b6408 100644 --- a/util.h +++ b/util.h @@ -211,7 +211,7 @@ int sock_l4_sa(const struct ctx *c, enum epoll_type type, const void *sa, socklen_t sl, const char *ifname, bool v6only); int sock_unix(char *sock_path); -void sock_probe_mem(struct ctx *c); +void sock_probe_features(struct ctx *c); long timespec_diff_ms(const struct timespec *a, const struct timespec *b); int64_t timespec_diff_us(const struct timespec *a, const struct timespec *b); void bitmap_set(uint8_t *map, unsigned bit); -- 2.51.1