static int
lookup_brc_multicast_group(int *multicast_group)
{
struct nl_sock *sock;
struct ofpbuf request, *reply;
struct nlattr *attrs[ARRAY_SIZE(brc_multicast_policy)];
int retval;
retval = nl_sock_create(NETLINK_GENERIC, &sock);
if (retval) {
return retval;
}
ofpbuf_init(&request, 0);
nl_msg_put_genlmsghdr(&request, 0, brc_family,
NLM_F_REQUEST, BRC_GENL_C_QUERY_MC, 1);
retval = nl_sock_transact(sock, &request, &reply);
ofpbuf_uninit(&request);
if (retval) {
nl_sock_destroy(sock);
return retval;
}
if (!nl_policy_parse(reply, NLMSG_HDRLEN + GENL_HDRLEN,
brc_multicast_policy, attrs,
ARRAY_SIZE(brc_multicast_policy))) {
nl_sock_destroy(sock);
ofpbuf_delete(reply);
return EPROTO;
}
*multicast_group = nl_attr_get_u32(attrs[BRC_GENL_A_MC_GROUP]);
nl_sock_destroy(sock);
ofpbuf_delete(reply);
return 0;
}
/* Closes 'dp'. */
void
dpif_close(struct dpif *dp)
{
if (dp) {
nl_sock_destroy(dp->sock);
}
}
/* Opens a socket for brcompat notifications. Returns 0 if successful,
* otherwise a positive errno value. */
static int
brc_open(struct nl_sock **sock)
{
int multicast_group = 0;
int retval;
retval = nl_lookup_genl_family(BRC_GENL_FAMILY_NAME, &brc_family);
if (retval) {
return retval;
}
retval = lookup_brc_multicast_group(&multicast_group);
if (retval) {
return retval;
}
retval = nl_sock_create(NETLINK_GENERIC, sock);
if (retval) {
return retval;
}
retval = nl_sock_join_mcgroup(*sock, multicast_group);
if (retval) {
nl_sock_destroy(*sock);
*sock = NULL;
}
return retval;
}
/* Looks up the Netlink multicast group and datapath index of a datapath
* by either the datapath index or name. If 'dp_idx' points to a value
* of '-1', then 'dp_name' is used to lookup the datapath. If successful,
* stores the multicast group in '*multicast_group' and the index in
* '*dp_idx' and returns 0. Otherwise, returns a positive errno value. */
static int
query_datapath(int *dp_idx, int *multicast_group, const char *dp_name)
{
struct nl_sock *sock;
struct ofpbuf request, *reply;
struct nlattr *attrs[ARRAY_SIZE(openflow_multicast_policy)];
int retval;
retval = nl_sock_create(NETLINK_GENERIC, 0, 0, 0, &sock);
if (retval) {
return retval;
}
ofpbuf_init(&request, 0);
nl_msg_put_genlmsghdr(&request, sock, 0, openflow_family, NLM_F_REQUEST,
DP_GENL_C_QUERY_DP, 1);
if (*dp_idx != -1) {
nl_msg_put_u32(&request, DP_GENL_A_DP_IDX, *dp_idx);
}
if (dp_name) {
nl_msg_put_string(&request, DP_GENL_A_DP_NAME, dp_name);
}
retval = nl_sock_transact(sock, &request, &reply);
ofpbuf_uninit(&request);
if (retval) {
nl_sock_destroy(sock);
return retval;
}
if (!nl_policy_parse(reply, NLMSG_HDRLEN + GENL_HDRLEN,
openflow_multicast_policy, attrs,
ARRAY_SIZE(openflow_multicast_policy))) {
nl_sock_destroy(sock);
ofpbuf_delete(reply);
return EPROTO;
}
*dp_idx = nl_attr_get_u32(attrs[DP_GENL_A_DP_IDX]);
*multicast_group = nl_attr_get_u32(attrs[DP_GENL_A_MC_GROUP]);
nl_sock_destroy(sock);
ofpbuf_delete(reply);
return 0;
}
/* Completes Netlink dump operation 'dump', which must have been initialized
* with nl_dump_start(). Returns 0 if the dump operation was error-free,
* otherwise a positive errno value describing the problem. */
int
nl_dump_done(struct nl_dump *dump)
{
/* Drain any remaining messages that the client didn't read. Otherwise the
* kernel will continue to queue them up and waste buffer space. */
while (!dump->status) {
struct ofpbuf reply;
if (!nl_dump_next(dump, &reply)) {
assert(dump->status);
}
}
if (dump->sock) {
if (dump->sock->dump) {
dump->sock->dump = NULL;
} else {
nl_sock_destroy(dump->sock);
}
}
ofpbuf_uninit(&dump->buffer);
return dump->status == EOF ? 0 : dump->status;
}
