/** Receive message from netlink and update interface table
*
* \param nlif_handle A pointer to a ::nlif_handle created
* \return 0 if OK
*/
int nlif_catch(struct nlif_handle *nlif_handle)
{
assert(nlif_handle != NULL);
if (nlif_handle->rtnl_handle)
return rtnl_receive(nlif_handle->rtnl_handle);
return -1;
}
/* rtnl_receive - receive netlink packets from rtnetlink socket */
int rtnl_receive(struct rtnl_handle *rtnl_handle)
{
int status;
char buf[8192];
struct sockaddr_nl nladdr;
struct iovec iov = { buf, sizeof(buf) };
struct nlmsghdr *h;
struct msghdr msg = {
.msg_name = &nladdr,
.msg_namelen = sizeof(nladdr),
.msg_iov = &iov,
.msg_iovlen = 1,
};
status = recvmsg(rtnl_handle->rtnl_fd, &msg, 0);
if (status < 0) {
if (errno == EINTR)
return 0;
rtnl_log(LOG_NOTICE, "OVERRUN on rtnl socket");
return -1;
}
if (status == 0) {
rtnl_log(LOG_ERROR, "EOF on rtnl socket");
return -1;
}
if (msg.msg_namelen != sizeof(nladdr)) {
rtnl_log(LOG_ERROR, "invalid address size");
return -1;
}
h = (struct nlmsghdr *) buf;
while (NLMSG_OK(h, status)) {
#if 0
if (h->nlmsg_pid != rtnl_local.nl_pid ||
h->nlmsg_seq != rtnl_dump) {
goto skip;
}
#endif
if (h->nlmsg_type == NLMSG_DONE) {
rtnl_log(LOG_NOTICE, "NLMSG_DONE");
return 0;
}
if (h->nlmsg_type == NLMSG_ERROR) {
struct nlmsgerr *err = NLMSG_DATA(h);
if (h->nlmsg_len>=NLMSG_LENGTH(sizeof(struct nlmsgerr)))
errno = -err->error;
rtnl_log(LOG_ERROR, "NLMSG_ERROR, errnp=%d",
errno);
return -1;
}
if (call_handler(rtnl_handle, h->nlmsg_type, h) == 0)
rtnl_log(LOG_NOTICE, "unhandled nlmsg_type %u",
h->nlmsg_type);
h = NLMSG_NEXT(h, status);
}
return 1;
}
int rtnl_receive_multi(struct rtnl_handle *rtnl_handle)
{
while (1) {
if (rtnl_receive(rtnl_handle) <= 0)
break;
}
return 1;
}
/* rtnl_open - constructor of rtnetlink module */
struct rtnl_handle *rtnl_open(void)
{
socklen_t addrlen;
struct rtnl_handle *h;
h = calloc(1, sizeof(struct rtnl_handle));
if (!h)
return NULL;
addrlen = sizeof(h->rtnl_local);
h->rtnl_local.nl_pid = getpid();
h->rtnl_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
if (h->rtnl_fd < 0) {
rtnl_log(LOG_ERROR, "unable to create rtnetlink socket");
goto err;
}
memset(&h->rtnl_local, 0, sizeof(h->rtnl_local));
h->rtnl_local.nl_family = AF_NETLINK;
h->rtnl_local.nl_groups = RTMGRP_LINK;
if (bind(h->rtnl_fd, (struct sockaddr *) &h->rtnl_local, addrlen) < 0) {
rtnl_log(LOG_ERROR, "unable to bind rtnetlink socket");
goto err_close;
}
if (getsockname(h->rtnl_fd,
(struct sockaddr *) &h->rtnl_local,
&addrlen) < 0) {
rtnl_log(LOG_ERROR, "cannot gescockname(rtnl_socket)");
goto err_close;
}
if (addrlen != sizeof(h->rtnl_local)) {
rtnl_log(LOG_ERROR, "invalid address size %u", addr_len);
goto err_close;
}
if (h->rtnl_local.nl_family != AF_NETLINK) {
rtnl_log(LOG_ERROR, "invalid AF %u", h->rtnl_local.nl_family);
goto err_close;
}
h->rtnl_seq = time(NULL);
return h;
err_close:
close(h->rtnl_fd);
err:
free(h);
return NULL;
}