Add netlink fd polling.

Signed-off-by: Benjamin Cama <benoar@dolka.fr>

diff --git a/l2tpns.c b/l2tpns.c
index 3d53622..8517ccf 100644 (file)
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -73,6 +73,7 @@ time_t basetime = 0;          // base clock
 char hostname[1000] = "";      // us.
 static int tunidx;             // ifr_ifindex of tun device
 int nlseqnum = 0;              // netlink sequence number
+int min_initok_nlseqnum = 0;   // minimun seq number for messages after init is ok
 static int syslog_log = 0;     // are we logging to syslog
 static FILE *log_stream = 0;   // file handle for direct logging (i.e. direct into file, not via syslog).
 uint32_t last_id = 0;          // Unique ID for radius accounting
@@ -559,7 +560,7 @@ static ssize_t netlink_send(struct nlmsghdr *nh)
        return sendmsg(nlfd, &msg, 0);
 }
 
-static ssize_t netlink_recv(char *buf, ssize_t len)
+static ssize_t netlink_recv(void *buf, ssize_t len)
 {
        struct sockaddr_nl nladdr;
        struct iovec iov;
@@ -636,7 +637,7 @@ static void inittun(void)
                resp_nh = (struct nlmsghdr *)buf;
                if (!NLMSG_OK (resp_nh, len))
                {
-                       LOG(0, 0, 0, "Malformed answer getting tun ifindex %d\n", len);
+                       LOG(0, 0, 0, "Malformed answer getting tun ifindex %ld\n", len);
                        exit(1);
                }
 
@@ -793,6 +794,13 @@ static void inittun(void)
                        LOG(0, 0, 0, "Error finishing setting up tun device: %s\n", strerror(errno));
                        exit(1);
                }
+
+               // if we get an error for seqnum < min_initok_nlseqnum,
+               // we must exit as initialization went wrong
+               if (config->ipv6_prefix.s6_addr[0])
+                       min_initok_nlseqnum = 3 + 1; // idx + if + addr
+               else
+                       min_initok_nlseqnum = 5 + 1; // idx + if + addr + 2*addr6
        }
 }
 
@@ -3669,8 +3677,8 @@ static int still_busy(void)
 # include "fake_epoll.h"
 #endif
 
-// the base set of fds polled: cli, cluster, tun, udp, control, dae
-#define BASE_FDS       6
+// the base set of fds polled: cli, cluster, tun, udp, control, dae, netlink
+#define BASE_FDS       7
 
 // additional polled fds
 #ifdef BGP
@@ -3694,8 +3702,8 @@ static void mainloop(void)
                exit(1);
        }
 
-       LOG(4, 0, 0, "Beginning of main loop.  clifd=%d, cluster_sockfd=%d, tunfd=%d, udpfd=%d, controlfd=%d, daefd=%d\n",
-               clifd, cluster_sockfd, tunfd, udpfd, controlfd, daefd);
+       LOG(4, 0, 0, "Beginning of main loop.  clifd=%d, cluster_sockfd=%d, tunfd=%d, udpfd=%d, controlfd=%d, daefd=%d, nlfd=%d\n",
+               clifd, cluster_sockfd, tunfd, udpfd, controlfd, daefd, nlfd);
 
        /* setup our fds to poll for input */
        {
@@ -3731,6 +3739,10 @@ static void mainloop(void)
                d[i].type = FD_TYPE_DAE;
                e.data.ptr = &d[i++];
                epoll_ctl(epollfd, EPOLL_CTL_ADD, daefd, &e);
+
+               d[i].type = FD_TYPE_NETLINK;
+               e.data.ptr = &d[i++];
+               epoll_ctl(epollfd, EPOLL_CTL_ADD, nlfd, &e);
        }
 
 #ifdef BGP
@@ -3867,6 +3879,27 @@ static void mainloop(void)
                                        break;
 #endif /* BGP */
 
+                               case FD_TYPE_NETLINK:
+                               {
+                                       struct nlmsghdr *nh = (struct nlmsghdr *)buf;
+                                       s = netlink_recv(buf, sizeof(buf));
+                                       if (nh->nlmsg_type == NLMSG_ERROR)
+                                       {
+                                               struct nlmsgerr *errmsg = NLMSG_DATA(nh);
+                                               if (errmsg->error && errmsg->msg.nlmsg_seq < min_initok_nlseqnum)
+                                               {
+                                                       LOG(0, 0, 0, "Got a fatal netlink error: seq %d flags %d code %d\n", nh->nlmsg_seq, nh->nlmsg_flags, errmsg->error);
+                                                       exit(1);
+                                               }
+                                               else
+                                                       LOG(1, 0, 0, "Got a netlink error: seq %d flags %d code %d\n", nh->nlmsg_seq, nh->nlmsg_flags, errmsg->error);
+                                       }
+                                       else
+                                               LOG(1, 0, 0, "Got a unknown netlink message: type %d seq %d flags %d\n", nh->nlmsg_type, nh->nlmsg_seq, nh->nlmsg_flags);
+                                       n--;
+                                       break;
+                               }
+
                                default:
                                        LOG(0, 0, 0, "Unexpected fd type returned from epoll_wait: %d\n", d->type);
                                }

diff --git a/l2tpns.h b/l2tpns.h
index 6849be9..26928d1 100644 (file)
--- a/l2tpns.h
+++ b/l2tpns.h
@@ -935,6 +935,7 @@ struct event_data {
                FD_TYPE_DAE,
                FD_TYPE_RADIUS,
                FD_TYPE_BGP,
+               FD_TYPE_NETLINK,
        } type;
        int index; // for RADIUS, BGP
 };