From cbca08cd38787559cfbe06756597b04ae97fe6ff Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Wed, 22 May 2024 19:31:12 +0200 Subject: [PATCH] tap: Split tap_sock_unix_init() into opening and listening parts We'll need to open and bind the socket a while before listening to it, so split that into two different functions. No functional changes intended. Signed-off-by: Stefano Brivio Reviewed-by: Richard W.M. Jones --- tap.c | 39 +++++++++++++++++++++++++++------------ 1 file changed, 27 insertions(+), 12 deletions(-) diff --git a/tap.c b/tap.c index cb6df5a..c9f580e 100644 --- a/tap.c +++ b/tap.c @@ -1095,14 +1095,14 @@ restart: } /** - * tap_sock_unix_init() - Create and bind AF_UNIX socket, listen for connection - * @c: Execution context + * tap_sock_unix_open() - Create and bind AF_UNIX socket + * @sock_path: Socket path. If empty, set on return (UNIX_SOCK_PATH as prefix) + * + * Return: socket descriptor on success, won't return on failure */ -static void tap_sock_unix_init(struct ctx *c) +static int tap_sock_unix_open(char *sock_path) { int fd = socket(AF_UNIX, SOCK_STREAM, 0); - union epoll_ref ref = { .type = EPOLL_TYPE_TAP_LISTEN }; - struct epoll_event ev = { 0 }; struct sockaddr_un addr = { .sun_family = AF_UNIX, }; @@ -1115,8 +1115,8 @@ static void tap_sock_unix_init(struct ctx *c) char *path = addr.sun_path; int ex, ret; - if (*c->sock_path) - memcpy(path, c->sock_path, UNIX_PATH_MAX); + if (*sock_path) + memcpy(path, sock_path, UNIX_PATH_MAX); else snprintf(path, UNIX_PATH_MAX - 1, UNIX_SOCK_PATH, i); @@ -1127,7 +1127,7 @@ static void tap_sock_unix_init(struct ctx *c) ret = connect(ex, (const struct sockaddr *)&addr, sizeof(addr)); if (!ret || (errno != ENOENT && errno != ECONNREFUSED && errno != EACCES)) { - if (*c->sock_path) + if (*sock_path) die("Socket path %s already in use", path); close(ex); @@ -1137,7 +1137,7 @@ static void tap_sock_unix_init(struct ctx *c) unlink(path); if (!bind(fd, (const struct sockaddr *)&addr, sizeof(addr)) || - *c->sock_path) + *sock_path) break; } @@ -1145,17 +1145,31 @@ static void tap_sock_unix_init(struct ctx *c) die("UNIX socket bind: %s", strerror(errno)); info("UNIX domain socket bound at %s\n", addr.sun_path); + if (!*sock_path) + memcpy(sock_path, addr.sun_path, UNIX_PATH_MAX); - listen(fd, 0); + return fd; +} - ref.fd = c->fd_tap_listen = fd; +/** + * tap_sock_unix_init() - Start listening for connections on AF_UNIX socket + * @c: Execution context + */ +static void tap_sock_unix_init(struct ctx *c) +{ + union epoll_ref ref = { .type = EPOLL_TYPE_TAP_LISTEN }; + struct epoll_event ev = { 0 }; + + listen(c->fd_tap_listen, 0); + + ref.fd = c->fd_tap_listen; ev.events = EPOLLIN | EPOLLET; ev.data.u64 = ref.u64; epoll_ctl(c->epollfd, EPOLL_CTL_ADD, c->fd_tap_listen, &ev); info("You can now start qemu (>= 7.2, with commit 13c6be96618c):"); info(" kvm ... -device virtio-net-pci,netdev=s -netdev stream,id=s,server=off,addr.type=unix,addr.path=%s", - addr.sun_path); + c->sock_path); info("or qrap, for earlier qemu versions:"); info(" ./qrap 5 kvm ... -net socket,fd=5 -net nic,model=virtio"); } @@ -1304,6 +1318,7 @@ void tap_sock_init(struct ctx *c) } if (c->mode == MODE_PASST) { + c->fd_tap_listen = tap_sock_unix_open(c->sock_path); tap_sock_unix_init(c); /* In passt mode, we don't know the guest's MAC address until it