static gint
socket_recv_messages (NiceSocket *nicesock,
NiceInputMessage *recv_messages, guint n_recv_messages)
{
guint i;
gboolean error = FALSE;
for (i = 0; i < n_recv_messages; i++) {
gssize len;
len = socket_recv_message (nicesock, &recv_messages[i]);
recv_messages[i].length = MAX (len, 0);
if (len < 0)
error = TRUE;
if (len <= 0)
break;
}
/* Was there an error processing the first message? */
if (error && i == 0)
return -1;
return i;
}
/* returns the number of bytes sent, or a negative error code */
int socket_write_message(sd_rtnl *nl, sd_rtnl_message *m) {
union {
struct sockaddr sa;
struct sockaddr_nl nl;
} addr = {
.nl.nl_family = AF_NETLINK,
};
ssize_t k;
assert(nl);
assert(m);
assert(m->hdr);
k = sendto(nl->fd, m->hdr, m->hdr->nlmsg_len,
0, &addr.sa, sizeof(addr));
if (k < 0)
return (errno == EAGAIN) ? 0 : -errno;
return k;
}
static int socket_recv_message(int fd, struct iovec *iov, uint32_t *_group, bool peek) {
uint8_t cred_buffer[CMSG_SPACE(sizeof(struct ucred)) +
CMSG_SPACE(sizeof(struct nl_pktinfo))];
struct msghdr msg = {
.msg_iov = iov,
.msg_iovlen = 1,
.msg_control = cred_buffer,
.msg_controllen = sizeof(cred_buffer),
};
struct cmsghdr *cmsg;
uint32_t group = 0;
bool auth = false;
int r;
assert(fd >= 0);
assert(iov);
r = recvmsg(fd, &msg, MSG_TRUNC | (peek ? MSG_PEEK : 0));
if (r < 0) {
/* no data */
if (errno == ENOBUFS)
log_debug("rtnl: kernel receive buffer overrun");
return (errno == EAGAIN) ? 0 : -errno;
} else if (r == 0)
/* connection was closed by the kernel */
return -ECONNRESET;
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_CREDENTIALS &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
struct ucred *ucred = (void *)CMSG_DATA(cmsg);
/* from the kernel */
if (ucred->uid == 0 && ucred->pid == 0)
auth = true;
} else if (cmsg->cmsg_level == SOL_NETLINK &&
cmsg->cmsg_type == NETLINK_PKTINFO &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct nl_pktinfo))) {
struct nl_pktinfo *pktinfo = (void *)CMSG_DATA(cmsg);
/* multi-cast group */
group = pktinfo->group;
}
}
if (!auth)
/* not from the kernel, ignore */
return 0;
if (group)
*_group = group;
return r;
}
/* On success, the number of bytes received is returned and *ret points to the received message
* which has a valid header and the correct size.
* If nothing useful was received 0 is returned.
* On failure, a negative error code is returned.
*/
int socket_read_message(sd_rtnl *rtnl) {
_cleanup_rtnl_message_unref_ sd_rtnl_message *first = NULL;
struct iovec iov = {};
uint32_t group = 0;
bool multi_part = false, done = false;
struct nlmsghdr *new_msg;
size_t len;
int r;
unsigned i = 0;
assert(rtnl);
assert(rtnl->rbuffer);
assert(rtnl->rbuffer_allocated >= sizeof(struct nlmsghdr));
/* read nothing, just get the pending message size */
r = socket_recv_message(rtnl->fd, &iov, &group, true);
if (r <= 0)
return r;
else
len = (size_t)r;
/* make room for the pending message */
if (!greedy_realloc((void **)&rtnl->rbuffer,
&rtnl->rbuffer_allocated,
len, sizeof(uint8_t)))
return -ENOMEM;
iov.iov_base = rtnl->rbuffer;
iov.iov_len = rtnl->rbuffer_allocated;
/* read the pending message */
r = socket_recv_message(rtnl->fd, &iov, &group, false);
if (r <= 0)
return r;
else
len = (size_t)r;
if (len > rtnl->rbuffer_allocated)
/* message did not fit in read buffer */
return -EIO;
if (NLMSG_OK(rtnl->rbuffer, len) && rtnl->rbuffer->nlmsg_flags & NLM_F_MULTI) {
multi_part = true;
for (i = 0; i < rtnl->rqueue_partial_size; i++) {
if (rtnl_message_get_serial(rtnl->rqueue_partial[i]) ==
rtnl->rbuffer->nlmsg_seq) {
first = rtnl->rqueue_partial[i];
break;
}
}
}
for (new_msg = rtnl->rbuffer; NLMSG_OK(new_msg, len); new_msg = NLMSG_NEXT(new_msg, len)) {
_cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
const NLType *nl_type;
if (!group && new_msg->nlmsg_pid != rtnl->sockaddr.nl.nl_pid)
/* not broadcast and not for us */
continue;
if (new_msg->nlmsg_type == NLMSG_NOOP)
/* silently drop noop messages */
continue;
if (new_msg->nlmsg_type == NLMSG_DONE) {
/* finished reading multi-part message */
done = true;
break;
}
/* check that we support this message type */
r = type_system_get_type(NULL, &nl_type, new_msg->nlmsg_type);
if (r < 0) {
if (r == -ENOTSUP)
log_debug("sd-rtnl: ignored message with unknown type: %u",
new_msg->nlmsg_type);
continue;
}
/* check that the size matches the message type */
if (new_msg->nlmsg_len < NLMSG_LENGTH(nl_type->size))
continue;
r = message_new_empty(rtnl, &m);
if (r < 0)
return r;
m->hdr = memdup(new_msg, new_msg->nlmsg_len);
if (!m->hdr)
return -ENOMEM;
/* seal and parse the top-level message */
r = sd_rtnl_message_rewind(m);
if (r < 0)
return r;
/* push the message onto the multi-part message stack */
if (first)
m->next = first;
first = m;
m = NULL;
}
if (len)
log_debug("sd-rtnl: discarding %zu bytes of incoming message", len);
if (!first)
return 0;
if (!multi_part || done) {
/* we got a complete message, push it on the read queue */
r = rtnl_rqueue_make_room(rtnl);
if (r < 0)
return r;
rtnl->rqueue[rtnl->rqueue_size ++] = first;
first = NULL;
if (multi_part && (i < rtnl->rqueue_partial_size)) {
/* remove the message form the partial read queue */
memmove(rtnl->rqueue_partial + i,rtnl->rqueue_partial + i + 1,
sizeof(sd_rtnl_message*) * (rtnl->rqueue_partial_size - i - 1));
rtnl->rqueue_partial_size --;
}
return 1;
} else {
/* we only got a partial multi-part message, push it on the
partial read queue */
if (i < rtnl->rqueue_partial_size) {
rtnl->rqueue_partial[i] = first;
} else {
r = rtnl_rqueue_partial_make_room(rtnl);
if (r < 0)
return r;
rtnl->rqueue_partial[rtnl->rqueue_partial_size ++] = first;
}
first = NULL;
return 0;
}
}
