Merge pull request xelerance#9 from sigwall/kernel

Fix kernel support for 2.6.23+

Makefile

@@ -62,7 +62,7 @@ OSFLAGS?= -DLINUX -I$(KERNELSRC)/include/
 # are packages seperately (eg kernel-headers on Fedora)
 # Note: 2.6.23+ support still needs some changes in the xl2tpd source
 #
-#OSFLAGS+= -DUSE_KERNEL
+OSFLAGS+= -DUSE_KERNEL
 #
 #
 # Uncomment the next line for FreeBSD

call.c

@@ -680,6 +680,8 @@ struct call *get_call (int tunnel, int call,  struct in_addr addr, int port,
         st->peer.sin_port = port;
 	st->refme  = refme;
 	st->refhim = refhim;
+        st->udp_fd = -1;
+        st->pppox_fd = -1;
         bcopy (&addr, &st->peer.sin_addr, sizeof (addr));
         st->next = tunnels.head;
         tunnels.head = st;

control.c

@@ -596,6 +596,11 @@ int control_finish (struct tunnel *t, struct call *c)
         if (gconfig.debug_state)
             l2tp_log (LOG_DEBUG, "%s: sending SCCCN\n", __FUNCTION__);
         control_xmit (buf);
+
+#ifdef USE_KERNEL
+        connect_pppol2tp(t);
+#endif
+
         /* Schedule a HELLO */
         tv.tv_sec = HELLO_DELAY;
         tv.tv_usec = 0;
@@ -608,6 +613,7 @@ int control_finish (struct tunnel *t, struct call *c)
 		  "Connection established to %s, %d.  Local: %d, Remote: %d (ref=%u/%u).\n",
 		  IPADDY (t->peer.sin_addr),
 		  ntohs (t->peer.sin_port), t->ourtid, t->tid, t->refme, t->refhim);
+
         if (t->lac)
         {
             /* This is part of a LAC, so we want to go ahead
@@ -635,6 +641,11 @@ int control_finish (struct tunnel *t, struct call *c)
 		  IPADDY (t->peer.sin_addr),
 		  ntohs (t->peer.sin_port), t->ourtid, t->tid, t->refme, t->refhim,
 		  t->lns->entname);
+
+#ifdef USE_KERNEL
+        connect_pppol2tp(t);
+#endif
+
         /* Schedule a HELLO */
         tv.tv_sec = HELLO_DELAY;
         tv.tv_usec = 0;

file.c

@@ -1154,6 +1154,7 @@ int set_ipsec_saref (char *word, char *value, int context, void *item)
 	    }
 	    if(g->forceuserspace != 1) {
 		    l2tp_log(LOG_WARNING, "IPsec SAref does not work with L2TP kernel mode yet, enabling forceuserspace=yes\n");
+		    g->forceuserspace = 1;
 	    }
 	    break;
     default:

l2tp.h

@@ -167,6 +167,8 @@ struct tunnel
     int ourrws;                 /* Receive Window Size */
     int rxspeed;		/* Receive bps */
     int txspeed;		/* Transmit bps */
+    int udp_fd;			/* UDP fd */
+    int pppox_fd;			/* PPPOX tunnel fd */
     struct call *self;
     struct lns *lns;            /* LNS that owns us */
     struct lac *lac;            /* LAC that owns us */
@@ -206,7 +208,6 @@ extern struct tunnel_list tunnels;
 extern void tunnel_close (struct tunnel *t);
 extern void network_thread ();
 extern int init_network ();
-extern int kernel_support;
 extern int server_socket;
 extern struct tunnel *new_tunnel ();
 extern struct packet_queue xmit_udp;
@@ -220,6 +221,10 @@ extern void control_xmit (void *);
 extern int ppd;
 extern int switch_io;           /* jz */
 extern int control_fd;
+#ifdef USE_KERNEL
+extern int kernel_support;
+extern int connect_pppol2tp (struct tunnel *t);
+#endif
 extern int start_pppd (struct call *c, struct ppp_opts *);
 extern void magic_lac_dial (void *);
 extern int get_entropy (unsigned char *, int);

network.c

@@ -22,6 +22,7 @@
 #include <unistd.h>
 #include <stdlib.h>
 #include <sys/ioctl.h>
+#include <sys/wait.h>
 #ifndef LINUX
 # include <sys/uio.h>
 #endif
@@ -36,7 +37,6 @@ int server_socket;              /* Server socket */
 int kernel_support;             /* Kernel Support there or not? */
 #endif
 
-
 int init_network (void)
 {
     long arg;
@@ -45,13 +45,18 @@ int init_network (void)
     server.sin_family = AF_INET;
     server.sin_addr.s_addr = gconfig.listenaddr; 
     server.sin_port = htons (gconfig.port);
+    int flags;
     if ((server_socket = socket (PF_INET, SOCK_DGRAM, 0)) < 0)
     {
         l2tp_log (LOG_CRIT, "%s: Unable to allocate socket. Terminating.\n",
              __FUNCTION__);
         return -EINVAL;
     };
 
+    flags = 1;
+    setsockopt(server_socket, SOL_SOCKET, SO_REUSEADDR, &flags, sizeof(flags));
+    setsockopt(server_socket, SOL_SOCKET, SO_NO_CHECK, &flags, sizeof(flags));
+
     if (bind (server_socket, (struct sockaddr *) &server, sizeof (server)))
     {
         close (server_socket);
@@ -94,7 +99,7 @@ int init_network (void)
         int kernel_fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
         if (kernel_fd < 0)
         {
-            l2tp_log (LOG_INFO, "L2TP kernel support not detected.\n");
+            l2tp_log (LOG_INFO, "L2TP kernel support not detected (try modprobing l2tp_ppp and pppol2tp)\n");
             kernel_support = 0;
         }
         else
@@ -321,6 +326,11 @@ int build_fdset (fd_set *readfds)
 
 	while (tun)
 	{
+		if (tun->udp_fd > -1) {
+			if (tun->udp_fd > max)
+				max = tun->udp_fd;
+			FD_SET (tun->udp_fd, readfds);
+		}
 		call = tun->call_head;
 		while (call)
 		{
@@ -390,6 +400,8 @@ void network_thread ()
     struct iovec iov;
     char cbuf[256];
     unsigned int refme, refhim;
+    int * currentfd;
+    int server_socket_processed;
 
     /* This one buffer can be recycled for everything except control packets */
     buf = new_buf (MAX_RECV_SIZE);
@@ -428,7 +440,21 @@ void network_thread ()
         {
             do_control ();
         }
-        if (FD_ISSET (server_socket, &readfds))
+        server_socket_processed = 0;
+        currentfd = NULL;
+        st = tunnels.head;
+        while (st || !server_socket_processed) {
+            if (st && (st->udp_fd == -1)) {
+                st=st->next;
+                continue;
+            }
+            if (st) {
+                currentfd = &st->udp_fd;
+            } else {
+                currentfd = &server_socket;
+                server_socket_processed = 1;
+            }
+            if (FD_ISSET (*currentfd, &readfds))
         {
             /*
              * Okay, now we're ready for reading and processing new data.
@@ -456,12 +482,19 @@ void network_thread ()
 	    msgh.msg_flags = 0;
 
 	    /* Receive one packet. */
-	    recvsize = recvmsg(server_socket, &msgh, 0);
+	    recvsize = recvmsg(*currentfd, &msgh, 0);
 
             if (recvsize < MIN_PAYLOAD_HDR_LEN)
             {
                 if (recvsize < 0)
                 {
+                    if (errno == ECONNREFUSED) {
+                        close(*currentfd);
+                    }
+                    if ((errno == ECONNREFUSED) ||
+                        (errno == EBADF)) {
+                        *currentfd = -1;
+                    }
                     if (errno != EAGAIN)
                         l2tp_log (LOG_WARNING,
                              "%s: recvfrom returned error %d (%s)\n",
@@ -566,6 +599,8 @@ void network_thread ()
 		}
 	    };
 	}
+	if (st) st=st->next;
+	}
 
 	/*
 	 * finished obvious sources, look for data from PPP connections.
@@ -638,3 +673,82 @@ void network_thread ()
     }
 
 }
+
+#ifdef USE_KERNEL
+int connect_pppol2tp(struct tunnel *t) {
+        if (kernel_support) {
+            int ufd = -1, fd2 = -1;
+            int flags;
+            struct sockaddr_pppol2tp sax;
+
+            struct sockaddr_in server;
+            server.sin_family = AF_INET;
+            server.sin_addr.s_addr = gconfig.listenaddr;
+            server.sin_port = htons (gconfig.port);
+            if ((ufd = socket (PF_INET, SOCK_DGRAM, 0)) < 0)
+            {
+                l2tp_log (LOG_CRIT, "%s: Unable to allocate UDP socket. Terminating.\n",
+                    __FUNCTION__);
+                return -EINVAL;
+            };
+
+            flags=1;
+            setsockopt(ufd, SOL_SOCKET, SO_REUSEADDR, &flags, sizeof(flags));
+            setsockopt(ufd, SOL_SOCKET, SO_NO_CHECK, &flags, sizeof(flags));
+
+            if (bind (ufd, (struct sockaddr *) &server, sizeof (server)))
+            {
+                close (ufd);
+                l2tp_log (LOG_CRIT, "%s: Unable to bind UDP socket: %s. Terminating.\n",
+                     __FUNCTION__, strerror(errno), errno);
+                return -EINVAL;
+            };
+            server = t->peer;
+            flags = fcntl(ufd, F_GETFL);
+            if (flags == -1 || fcntl(ufd, F_SETFL, flags | O_NONBLOCK) == -1) {
+                l2tp_log (LOG_WARNING, "%s: Unable to set UDP socket nonblock.\n",
+                     __FUNCTION__);
+                return -EINVAL;
+            }
+            if (connect (ufd, (struct sockaddr *) &server, sizeof(server)) < 0) {
+                l2tp_log (LOG_CRIT, "%s: Unable to connect UDP peer. Terminating.\n",
+                 __FUNCTION__);
+                return -EINVAL;
+            }
+
+            t->udp_fd=ufd;
+
+            fd2 = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
+            if (fd2 < 0) {
+                l2tp_log (LOG_WARNING, "%s: Unable to allocate PPPoL2TP socket.\n",
+                     __FUNCTION__);
+                return -EINVAL;
+            }
+            flags = fcntl(fd2, F_GETFL);
+            if (flags == -1 || fcntl(fd2, F_SETFL, flags | O_NONBLOCK) == -1) {
+                l2tp_log (LOG_WARNING, "%s: Unable to set PPPoL2TP socket nonblock.\n",
+                     __FUNCTION__);
+                return -EINVAL;
+            }
+            sax.sa_family = AF_PPPOX;
+            sax.sa_protocol = PX_PROTO_OL2TP;
+            sax.pppol2tp.pid = 0;
+            sax.pppol2tp.fd = t->udp_fd;
+            sax.pppol2tp.addr.sin_addr.s_addr = t->peer.sin_addr.s_addr;
+            sax.pppol2tp.addr.sin_port = t->peer.sin_port;
+            sax.pppol2tp.addr.sin_family = AF_INET;
+            sax.pppol2tp.s_tunnel  = t->ourtid;
+            sax.pppol2tp.s_session = 0;
+            sax.pppol2tp.d_tunnel  = t->tid;
+            sax.pppol2tp.d_session = 0;
+            if ((connect(fd2, (struct sockaddr *)&sax, sizeof(sax))) < 0) {
+                l2tp_log (LOG_WARNING, "%s: Unable to connect PPPoL2TP socket. %d %s\n",
+                     __FUNCTION__, errno, strerror(errno));
+                close(fd2);
+                return -EINVAL;
+            }
+            t->pppox_fd = fd2;
+        }
+    return 0;
+}
+#endif