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 <sbrivio@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
This commit is contained in:
Stefano Brivio 2024-05-22 19:31:12 +02:00
parent fcfb592adc
commit cbca08cd38

39
tap.c
View file

@ -1095,14 +1095,14 @@ restart:
} }
/** /**
* tap_sock_unix_init() - Create and bind AF_UNIX socket, listen for connection * tap_sock_unix_open() - Create and bind AF_UNIX socket
* @c: Execution context * @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); 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 = { struct sockaddr_un addr = {
.sun_family = AF_UNIX, .sun_family = AF_UNIX,
}; };
@ -1115,8 +1115,8 @@ static void tap_sock_unix_init(struct ctx *c)
char *path = addr.sun_path; char *path = addr.sun_path;
int ex, ret; int ex, ret;
if (*c->sock_path) if (*sock_path)
memcpy(path, c->sock_path, UNIX_PATH_MAX); memcpy(path, sock_path, UNIX_PATH_MAX);
else else
snprintf(path, UNIX_PATH_MAX - 1, UNIX_SOCK_PATH, i); 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)); ret = connect(ex, (const struct sockaddr *)&addr, sizeof(addr));
if (!ret || (errno != ENOENT && errno != ECONNREFUSED && if (!ret || (errno != ENOENT && errno != ECONNREFUSED &&
errno != EACCES)) { errno != EACCES)) {
if (*c->sock_path) if (*sock_path)
die("Socket path %s already in use", path); die("Socket path %s already in use", path);
close(ex); close(ex);
@ -1137,7 +1137,7 @@ static void tap_sock_unix_init(struct ctx *c)
unlink(path); unlink(path);
if (!bind(fd, (const struct sockaddr *)&addr, sizeof(addr)) || if (!bind(fd, (const struct sockaddr *)&addr, sizeof(addr)) ||
*c->sock_path) *sock_path)
break; break;
} }
@ -1145,17 +1145,31 @@ static void tap_sock_unix_init(struct ctx *c)
die("UNIX socket bind: %s", strerror(errno)); die("UNIX socket bind: %s", strerror(errno));
info("UNIX domain socket bound at %s\n", addr.sun_path); 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.events = EPOLLIN | EPOLLET;
ev.data.u64 = ref.u64; ev.data.u64 = ref.u64;
epoll_ctl(c->epollfd, EPOLL_CTL_ADD, c->fd_tap_listen, &ev); epoll_ctl(c->epollfd, EPOLL_CTL_ADD, c->fd_tap_listen, &ev);
info("You can now start qemu (>= 7.2, with commit 13c6be96618c):"); 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", 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("or qrap, for earlier qemu versions:");
info(" ./qrap 5 kvm ... -net socket,fd=5 -net nic,model=virtio"); 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) { if (c->mode == MODE_PASST) {
c->fd_tap_listen = tap_sock_unix_open(c->sock_path);
tap_sock_unix_init(c); tap_sock_unix_init(c);
/* In passt mode, we don't know the guest's MAC address until it /* In passt mode, we don't know the guest's MAC address until it