int opal_btl_usnic_nl_ip_rt_lookup(struct usnic_rtnl_sk *unlsk,
const char *src_ifname,
uint32_t src_addr,
uint32_t dst_addr, int *metric)
{
struct nl_msg *nlm;
struct rtmsg rmsg;
struct nl_lookup_arg arg;
int msg_cnt;
int err;
int oif;
oif = if_nametoindex(src_ifname);
if (0 == oif) {
return errno;
}
arg.nh_addr = 0;
arg.oif = oif;
arg.found = 0;
arg.replied = 0;
arg.unlsk = unlsk;
arg.msg_count = msg_cnt = 0;
memset(&rmsg, 0, sizeof(rmsg));
rmsg.rtm_family = AF_INET;
rmsg.rtm_dst_len = sizeof(dst_addr)*8;
rmsg.rtm_src_len = sizeof(src_addr)*8;
nlm = nlmsg_alloc_simple(RTM_GETROUTE, 0);
nlmsg_append(nlm, &rmsg, sizeof(rmsg), NLMSG_ALIGNTO);
nla_put_u32(nlm, RTA_DST, dst_addr);
nla_put_u32(nlm, RTA_SRC, src_addr);
err = rtnl_send_ack_disable(unlsk, nlm);
nlmsg_free(nlm);
if (err < 0) {
usnic_err("Failed to send nl route message to kernel, "
"error %s\n", nl_geterror());
return err;
}
err = nl_socket_modify_cb(unlsk->nlh, NL_CB_MSG_IN, NL_CB_CUSTOM,
rtnl_raw_parse_cb, &arg);
if (err != 0) {
usnic_err("Failed to setup callback function, error %s\n", nl_geterror());
return err;
}
while (!arg.replied) {
err = nl_recvmsgs_default(unlsk->nlh);
if (err < 0) {
usnic_err("Failed to receive nl route message from "
"kernel, error %s\n", nl_geterror());
return err;
}
/*
* the return value of nl_recvmsgs_default does not tell
* whether it returns because of successful read or socket
* timeout. So we compare msg count before and after the call
* to decide if no new message arrives. In such case,
* this function needs to terminate to prevent the caller from
* blocking forever
* NL_CB_MSG_IN traps every received message, so
* there should be no premature exit
*/
if (msg_cnt != arg.msg_count)
msg_cnt = arg.msg_count;
else
break;
}
if (arg.found) {
if (metric != NULL) {
*metric = arg.metric;
}
return 0;
}
else {
return -1;
}
}
int ompi_btl_usnic_nl_ip_rt_lookup(struct usnic_rtnl_sk *unlsk,
const char *src_ifname,
uint32_t src_addr,
uint32_t dst_addr, int *metric)
{
struct nl_msg *nlm;
struct rtmsg rmsg;
struct nl_lookup_arg arg;
int msg_cnt;
int err;
int oif;
oif = if_nametoindex(src_ifname);
if (0 == oif) {
return errno;
}
arg.nh_addr = 0;
arg.oif = oif;
arg.found = 0;
arg.replied = 0;
arg.unlsk = unlsk;
arg.msg_count = msg_cnt = 0;
memset(&rmsg, 0, sizeof(rmsg));
rmsg.rtm_family = AF_INET;
rmsg.rtm_dst_len = sizeof(dst_addr)*8;
rmsg.rtm_src_len = sizeof(src_addr)*8;
nlm = nlmsg_alloc_simple(RTM_GETROUTE, 0);
nlmsg_append(nlm, &rmsg, sizeof(rmsg), NLMSG_ALIGNTO);
nla_put_u32(nlm, RTA_DST, dst_addr);
nla_put_u32(nlm, RTA_SRC, src_addr);
err = rtnl_send_ack_disable(unlsk, nlm);
nlmsg_free(nlm);
if (err < 0) {
usnic_err("Failed to send rtnl query %s\n", nl_geterror(err));
return err;
}
err = nl_socket_modify_cb(unlsk->sock, NL_CB_MSG_IN, NL_CB_CUSTOM,
rtnl_raw_parse_cb, &arg);
if (err != 0) {
usnic_err("Failed to setup callback function, error %s\n",
nl_geterror(err));
return err;
}
while (!arg.replied) {
err = nl_recvmsgs_default(unlsk->sock);
if (err < 0) {
/* err will be returned as -NLE_AGAIN if the socket times out */
usnic_err("Failed to receive rtnl query results %s\n",
nl_geterror(err));
return err;
}
}
if (arg.found) {
if (metric != NULL) {
*metric = arg.metric;
}
return 0;
}
else {
return -1;
}
}
