static void print_header_content(FILE *ofd, struct nlmsghdr *n)
{
char flags[128];
char type[32];
fprintf(ofd, "type=%s length=%u flags=<%s> sequence-nr=%u pid=%u",
nl_nlmsgtype2str(n->nlmsg_type, type, sizeof(type)),
n->nlmsg_len, nl_nlmsg_flags2str(n->nlmsg_flags, flags,
sizeof(flags)), n->nlmsg_seq, n->nlmsg_pid);
}
static char *nlmsg_type2str(uint16_t proto, uint16_t type, char *buf, int len)
{
if (proto == NETLINK_ROUTE && type < RTM_MAX) {
const char *name = nlmsg_rtnl_type2str(type);
if (name) {
strncpy(buf, name, len);
return buf;
}
}
return nl_nlmsgtype2str(type, buf, len);
}
static int usnic_rt_raw_parse_cb(struct nl_msg *msg, void *arg)
{
struct usnic_rt_cb_arg *lookup_arg = (struct usnic_rt_cb_arg *)arg;
struct usnic_nl_sk *unlsk = lookup_arg->unlsk;
struct nlmsghdr *nlm_hdr = nlmsg_hdr(msg);
struct rtmsg *rtm;
struct nlattr *tb[RTA_MAX + 1];
int found = 0;
int err;
INC_CB_MSGCNT(lookup_arg);
if (!usnic_is_nlreply_expected(unlsk, nlm_hdr)) {
usnic_nlmsg_dump(msg);
return NL_SKIP;
}
if (usnic_is_nlreply_err(nlm_hdr, lookup_arg)) {
usnic_nlmsg_dump(msg);
return NL_SKIP;
}
if (nlm_hdr->nlmsg_type != RTM_NEWROUTE) {
char buf[128];
nl_nlmsgtype2str(nlm_hdr->nlmsg_type, buf, sizeof(buf));
usnic_err("Received an invalid route request reply message type: %s\n",
buf);
usnic_nlmsg_dump(msg);
return NL_SKIP;
}
rtm = nlmsg_data(nlm_hdr);
if (rtm->rtm_family != AF_INET) {
usnic_err("RTM message contains invalid AF family: %u\n",
rtm->rtm_family);
usnic_nlmsg_dump(msg);
return NL_SKIP;
}
err = nlmsg_parse(nlm_hdr, sizeof(struct rtmsg), tb, RTA_MAX,
route_policy);
if (err < 0) {
usnic_err("nlmsg parse error %s\n", NL_GETERROR(err));
usnic_nlmsg_dump(msg);
return NL_SKIP;
}
if (tb[RTA_OIF]) {
if (nla_get_u32(tb[RTA_OIF]) == (uint32_t)lookup_arg->oif)
found = 1;
else
usnic_err("Retrieved route has a different outgoing interface %d (expected %d)\n",
nla_get_u32(tb[RTA_OIF]),
lookup_arg->oif);
}
if (found && tb[RTA_GATEWAY])
lookup_arg->nh_addr = nla_get_u32(tb[RTA_GATEWAY]);
lookup_arg->found = found;
return NL_STOP;
}
