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sd-bus: introduce bus_process_cmsg()

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- Close all fds on failure.
- Close pidfd on success.
This commit is contained in:
Yu Watanabe
2024-10-08 19:56:00 +09:00
parent 9f0d2d64cc
commit 5f9f38b8df
1 changed files with 52 additions and 46 deletions
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src/libsystemd/sd-bus/bus-socket.c
+52 -46
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@@ -553,6 +553,52 @@ static int bus_socket_write_auth(sd_bus *b) {
return bus_socket_auth_verify(b);
}
static int bus_process_cmsg(sd_bus *bus, struct msghdr *mh, bool allow_fds) {
_cleanup_close_ int pidfd = -EBADF;
const int *fds = NULL;
size_t n_fds = 0;
assert(bus);
assert(mh);
CLEANUP_ARRAY(fds, n_fds, close_many);
struct cmsghdr *cmsg;
CMSG_FOREACH(cmsg, mh)
if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
assert(!fds);
fds = CMSG_TYPED_DATA(cmsg, int);
n_fds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
} else if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_PIDFD) {
log_debug("Got unexpected auxiliary pidfd, ignoring.");
assert(pidfd < 0);
pidfd = *CMSG_TYPED_DATA(cmsg, int);
} else
log_debug("Got unexpected auxiliary data with level=%d and type=%d, ignoring.",
cmsg->cmsg_level, cmsg->cmsg_type);
if (!allow_fds) {
if (fds)
/* Whut? We received fds during the auth protocol or so? Somebody is playing games
* with us. Close them all, and fail */
return -EIO;
return 0;
}
if (!GREEDY_REALLOC(bus->fds, bus->n_fds + n_fds))
return -ENOMEM;
FOREACH_ARRAY(i, fds, n_fds)
bus->fds[bus->n_fds++] = fd_move_above_stdio(*i);
TAKE_PTR(fds);
n_fds = 0;
return 0;
}
static int bus_socket_read_auth(sd_bus *b) {
struct msghdr mh;
struct iovec iov = {};
@@ -620,22 +666,9 @@ static int bus_socket_read_auth(sd_bus *b) {
b->rbuffer_size += k;
if (handle_cmsg) {
struct cmsghdr *cmsg;
CMSG_FOREACH(cmsg, &mh)
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS) {
int j;
/* Whut? We received fds during the auth
* protocol? Somebody is playing games with
* us. Close them all, and fail */
j = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
close_many(CMSG_TYPED_DATA(cmsg, int), j);
return -EIO;
} else
log_debug("Got unexpected auxiliary data with level=%d and type=%d",
cmsg->cmsg_level, cmsg->cmsg_type);
r = bus_process_cmsg(b, &mh, /* allow_fds = */ false);
if (r < 0)
return r;
}
r = bus_socket_auth_verify(b);
@@ -1405,36 +1438,9 @@ int bus_socket_read_message(sd_bus *bus) {
bus->rbuffer_size += k;
if (handle_cmsg) {
struct cmsghdr *cmsg;
CMSG_FOREACH(cmsg, &mh)
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS) {
int n, *f, i;
n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
if (!bus->can_fds) {
/* Whut? We received fds but this
* isn't actually enabled? Close them,
* and fail */
close_many(CMSG_TYPED_DATA(cmsg, int), n);
return -EIO;
}
f = reallocarray(bus->fds, bus->n_fds + n, sizeof(int));
if (!f) {
close_many(CMSG_TYPED_DATA(cmsg, int), n);
return -ENOMEM;
}
for (i = 0; i < n; i++)
f[bus->n_fds++] = fd_move_above_stdio(CMSG_TYPED_DATA(cmsg, int)[i]);
bus->fds = f;
} else
log_debug("Got unexpected auxiliary data with level=%d and type=%d",
cmsg->cmsg_level, cmsg->cmsg_type);
r = bus_process_cmsg(bus, &mh, bus->can_fds);
if (r < 0)
return r;
}
r = bus_socket_read_message_need(bus, &need);