- Ignore gateway address in Framed-Route (from Jonathan McDowell).
[l2tpns.git] / ppp.c
diff --git a/ppp.c b/ppp.c
index a0f7cc2..f0e47e0 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.21 2004-11-05 04:55:27 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.26 2004-11-16 07:54:32 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -23,7 +23,7 @@ extern u32 eth_tx;
 extern time_t time_now;
 extern struct configt *config;
 
-void sendccp(tunnelidt t, sessionidt s);
+static void sendccp(tunnelidt t, sessionidt s);
 
 // Process PAP messages
 void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
@@ -224,7 +224,7 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
        radiussend(r, RADIUSAUTH);
 }
 
-char *ppp_lcp_types[] = {
+static char *ppp_lcp_types[] = {
        NULL,
        "ConfigReq",
        "ConfigAck",
@@ -240,7 +240,7 @@ char *ppp_lcp_types[] = {
        "IdentRequest",
 };
 
-void dumplcp(u8 *p, int l)
+static void dumplcp(u8 *p, int l)
 {
        int x = l - 4;
        u8 *o = (p + 4);
@@ -275,46 +275,45 @@ void dumplcp(u8 *p, int l)
                                else
                                        LOG(4, 0, 0, 0, "    %s odd length %d\n", lcp_types[type], length);
                                break;
+                       case 2: // Async-Control-Character-Map
+                               if (length == 6)
+                               {
+                                       u32 asyncmap = ntohl(*(u32 *)(o + 2));
+                                       LOG(4, 0, 0, 0, "    %s %x\n", lcp_types[type], asyncmap);
+                               }
+                               else
+                                       LOG(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
+                               break;
                        case 3: // Authentication-Protocol
+                               if (length == 4)
                                {
-                                       if (length == 4)
-                                       {
-                                               int proto = ntohs(*(u16 *)(o + 2));
-                                               LOG(4, 0, 0, 0, "   %s 0x%x (%s)\n", lcp_types[type], proto,
-                                                       proto == PPPCHAP ? "CHAP" :
-                                                       proto == PPPPAP  ? "PAP"  : "UNKNOWN");
-                                       }
-                                       else
-                                               LOG(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
-                                       break;
+                                       int proto = ntohs(*(u16 *)(o + 2));
+                                       LOG(4, 0, 0, 0, "   %s 0x%x (%s)\n", lcp_types[type], proto,
+                                               proto == PPPCHAP ? "CHAP" :
+                                               proto == PPPPAP  ? "PAP"  : "UNKNOWN");
                                }
+                               else
+                                       LOG(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
+                               break;
                        case 4: // Quality-Protocol
                                {
                                        u32 qp = ntohl(*(u32 *)(o + 2));
                                        LOG(4, 0, 0, 0, "    %s %x\n", lcp_types[type], qp);
-                                       break;
                                }
+                               break;
                        case 5: // Magic-Number
+                               if (length == 6)
                                {
-                                       if (length == 6)
-                                       {
-                                               u32 magicno = ntohl(*(u32 *)(o + 2));
-                                               LOG(4, 0, 0, 0, "    %s %x\n", lcp_types[type], magicno);
-                                       }
-                                       else
-                                               LOG(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
-                                       break;
+                                       u32 magicno = ntohl(*(u32 *)(o + 2));
+                                       LOG(4, 0, 0, 0, "    %s %x\n", lcp_types[type], magicno);
                                }
+                               else
+                                       LOG(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
+                               break;
                        case 7: // Protocol-Field-Compression
-                               {
-                                       LOG(4, 0, 0, 0, "    %s\n", lcp_types[type]);
-                                       break;
-                               }
                        case 8: // Address-And-Control-Field-Compression
-                               {
-                                       LOG(4, 0, 0, 0, "    %s\n", lcp_types[type]);
-                                       break;
-                               }
+                               LOG(4, 0, 0, 0, "    %s\n", lcp_types[type]);
+                               break;
                        default:
                                LOG(2, 0, 0, 0, "    Unknown PPP LCP Option type %d\n", type);
                                break;
@@ -359,6 +358,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
        {
                int x = l - 4;
                u8 *o = (p + 4);
+               u8 response = 0;
 
                LOG(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l);
                if (config->debug > 3) dumplcp(p, l);
@@ -367,97 +367,116 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
                {
                        int type = o[0];
                        int length = o[1];
-                       if (length == 0 || type == 0) break;
+                       if (length == 0 || type == 0 || x < length) break;
                        switch (type)
                        {
                                case 1: // Maximum-Receive-Unit
                                        session[s].mru = ntohs(*(u16 *)(o + 2));
                                        break;
-                               case 2: // asyncmap
-                                       LOG_HEX(2, "PPP LCP Packet", p, l);
-                                       LOG(2, 0, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_types[(int)*p], ntohs( ((u16 *) p)[1]) );
+
+                               case 2: // Async-Control-Character-Map
+                                       if (!ntohl(*(u32 *)(o + 2))) // all bits zero is OK
+                                               break;
+
+                                       if (response && response != ConfigNak) // rej already queued
+                                               break;
+
+                                       LOG(2, session[s].ip, s, t, "    Remote requesting asyncmap.  Rejecting.\n");
+                                       if (!response)
+                                       {
+                                               q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+                                               if (!q)
+                                               {
+                                                       LOG(2, session[s].ip, s, t, " Failed to send packet.\n");
+                                                       break;
+                                               }
+                                               response = *q++ = ConfigNak;
+                                       }
+                                       *q++ = type;
+                                       *q++ = 6;
+                                       memset(q, 0, 4); // asyncmap 0
+                                       q += 4;
                                        break;
+
                                case 3: // Authentication-Protocol
                                        {
                                                int proto = ntohs(*(u16 *)(o + 2));
+                                               char proto_name[] = "0x0000";
+                                               if (proto == PPPPAP)
+                                                       break;
+
+                                               if (response && response != ConfigNak) // rej already queued
+                                                       break;
+
                                                if (proto == PPPCHAP)
-                                               {
-                                                       LOG(2, session[s].ip, s, t, "    Remote end is trying to do CHAP. Rejecting it.\n");
+                                                       strcpy(proto_name, "CHAP");
+                                               else
+                                                       sprintf(proto_name, "%#4.4x", proto);
 
+                                               LOG(2, session[s].ip, s, t, "    Remote requesting %s authentication.  Rejecting.\n", proto_name);
+
+                                               if (!response)
+                                               {
+                                                       q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
                                                        if (!q)
                                                        {
-                                                               q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-                                                               if (!q) {
-                                                                       LOG(2, session[s].ip, s, t, " Failed to send packet.\n");
-                                                                       break;
-                                                               }
-                                                               *q++ = ConfigNak;
+                                                               LOG(2, session[s].ip, s, t, " Failed to send packet.\n");
+                                                               break;
                                                        }
-                                                       memcpy(q, o, length);
-                                                       *(u16 *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead
-                                                       q += length;
+                                                       response = *q++ = ConfigNak;
                                                }
-                                               break;
+                                               memcpy(q, o, length);
+                                               *(u16 *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead
+                                               q += length;
                                        }
+                                       break;
+
                                case 5: // Magic-Number
-                                       {
-                                               magicno = ntohl(*(u32 *)(o + 2));
-                                               break;
-                                       }
+                                       magicno = ntohl(*(u32 *)(o + 2));
+                                       break;
+
                                case 4: // Quality-Protocol
                                case 7: // Protocol-Field-Compression
                                case 8: // Address-And-Control-Field-Compression
-                                               break;
-                               case 13: // CallBack option for LCP extention of win2000/routers L2TP client
-                               case 17:
-                               case 18:
-                               {
-                                       // Reject LCP CallBack
-                                       LOG(2, session[s].ip, s, t, "    PPP LCP Option type %d, len=%d\n", type, length);
-                                       memcpy(p + 4, o, length);
-                                       *(u16 *)(p + 2) = htons(length + 4);
-                                       *p = ConfigRej;
-                                       q = makeppp(b,sizeof(b), p, length + 4, t, s, PPPLCP);
-                                       tunnelsend(b, 12 + length + 4, t);
-                                       return;
+                                       break;
+
+                               default: // Reject any unknown options
+                                       LOG(2, session[s].ip, s, t, "    Rejecting PPP LCP Option type %d\n", type);
+                                       if (!response || response != ConfigRej) // drop nak in favour of rej
+                                       {
+                                               q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+                                               if (!q)
+                                               {
+                                                       LOG(2, session[s].ip, s, t, " Failed to send packet.\n");
+                                                       break;
+                                               }
+                                               response = *q++ = ConfigRej;
                                        }
 
-                               default:
-                                       // Reject Unknown LCP Option to stop to send it again
-                                       LOG(2, session[s].ip, s, t, "    Unknown PPP LCP Option type %d\n", type);
-                                       memcpy(p + 4, o, length);
-                                       *(u16 *)(p + 2) = htons(length + 4);
-                                       *p = ConfigRej;
-                                       q = makeppp(b,sizeof(b), p, length + 4, t, s, PPPLCP);
-                                       tunnelsend(b, 12 + length + 4, t);
-                                       return;
+                                       memcpy(q, o, length);
+                                       q += length;
                        }
                        x -= length;
                        o += length;
                }
 
-               if (!(session[s].flags & SF_LCP_ACKED))
-                       initlcp(t, s);
-
-               if (!q)
+               if (!response)
                {
                        // Send back a ConfigAck
-                       LOG(3, session[s].ip, s, t, "ConfigReq accepted, sending as Ack\n");
                        q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
                        if (!q)
                        {
                                LOG(3, session[s].ip, s, t, " failed to create packet.\n");
                                return;
                        }
-                       *q = ConfigAck;
-                       tunnelsend(b, l + (q - b), t);
-               }
-               else
-               {
-                       // Already built a ConfigNak... send it
-                       LOG(3, session[s].ip, s, t, "Sending ConfigNak\n");
-                       tunnelsend(b, l + (q - b), t);
+                       response = *q = ConfigAck;
                }
+
+               LOG(3, session[s].ip, s, t, "Sending %s\n", ppp_lcp_types[response]);
+               tunnelsend(b, l + (q - b), t);
+
+               if (!(session[s].flags & SF_LCP_ACKED))
+                       initlcp(t, s);
        }
        else if (*p == ConfigNak)
        {
@@ -469,7 +488,8 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
        {
                *p = TerminateAck;      // close
                q = makeppp(b, sizeof(b),  p, l, t, s, PPPLCP);
-               if (!q) {
+               if (!q)
+               {
                        LOG(3, session[s].ip, s, t, "Failed to create PPP packet in processlcp.\n");
                        return;
                }
@@ -486,7 +506,8 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
                *p = EchoReply;         // reply
                *(u32 *) (p + 4) = htonl(session[s].magic); // our magic number
                q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-               if (!q) {
+               if (!q)
+               {
                        LOG(3, session[s].ip, s, t, " failed to send EchoReply.\n");
                        return;
                }
@@ -522,6 +543,26 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
        }
 }
 
+// find a PPP option, returns point to option, or 0 if not found
+static u8 *findppp(u8 *b, u8 mtype)
+{
+       u16 l = ntohs(*(u16 *) (b + 2));
+       if (l < 4)
+               return 0;
+       b += 4;
+       l -= 4;
+       while (l)
+       {
+               if (l < b[1] || !b[1])
+                       return 0;               // faulty
+               if (*b == mtype)
+                       return b;
+               l -= b[1];
+               b += b[1];
+       }
+       return 0;
+}
+
 // Process IPCP messages
 void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
@@ -688,12 +729,6 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
                return;
        }
 
-       if (session[s].snoop_ip && session[s].snoop_port)
-       {
-               // Snooping this session
-               snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
-       }
-
        // Add on the tun header
        p -= 4;
        *(u32 *)p = htonl(0x00000800);
@@ -704,16 +739,6 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
                return;
        }
 
-       session[s].cin += l - 4;
-       session[s].total_cin += l - 4;
-       sess_count[s].cin += l - 4;
-
-       session[s].pin++;
-       eth_tx += l - 4;
-
-       STAT(tun_tx_packets);
-       INC_STAT(tun_tx_bytes, l);
-
        if (session[s].tbf_in && config->cluster_iam_master) { // Are we throttled and a master?? actually handle the throttled packets.
                tbf_queue_packet(session[s].tbf_in, p, l);
                return;
@@ -725,8 +750,25 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
                STAT(tun_tx_errors);
                LOG(0, 0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
                        l, strerror(errno), tunfd, p);
+
+               return;
        }
 
+       if (session[s].snoop_ip && session[s].snoop_port)
+       {
+               // Snooping this session
+               snoop_send_packet(p + 4, l - 4, session[s].snoop_ip, session[s].snoop_port);
+       }
+
+       session[s].cin += l - 4;
+       session[s].total_cin += l - 4;
+       sess_count[s].cin += l - 4;
+
+       session[s].pin++;
+       eth_tx += l - 4;
+
+       STAT(tun_tx_packets);
+       INC_STAT(tun_tx_bytes, l - 4);
 }
 
 //
@@ -736,11 +778,20 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
 void send_ipin(sessionidt s, u8 *buf, int len)
 {
        LOG_HEX(5, "IP in throttled", buf, len);
+
        if (write(tunfd, buf, len) < 0)
        {
                STAT(tun_tx_errors);
                LOG(0, 0, 0, 0, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
                        len, strerror(errno), tunfd, buf);
+
+               return;
+       }
+
+       if (session[s].snoop_ip && session[s].snoop_port)
+       {
+               // Snooping this session
+               snoop_send_packet(buf + 4, len - 4, session[s].snoop_ip, session[s].snoop_port);
        }
 
        // Increment packet counters
@@ -750,6 +801,9 @@ void send_ipin(sessionidt s, u8 *buf, int len)
 
        session[s].pin++;
        eth_tx += len - 4;
+
+       STAT(tun_tx_packets);
+       INC_STAT(tun_tx_bytes, len - 4);
 }
 
 
@@ -828,7 +882,8 @@ void sendchap(tunnelidt t, sessionidt s)
                return ;
        }
        q = makeppp(b, sizeof(b), 0, 0, t, s, PPPCHAP);
-       if (!q) {
+       if (!q)
+       {
                LOG(1, 0, s, t, "failed to send CHAP challenge.\n");
                return;
        }
@@ -875,33 +930,14 @@ u8 *makeppp(u8 *b, int size, u8 *p, int l, tunnelidt t, sessionidt s, u16 mtype)
        return b;
 }
 
-// find a PPP option, returns point to option, or 0 if not found
-u8 *findppp(u8 *b, u8 mtype)
-{
-       u16 l = ntohs(*(u16 *) (b + 2));
-       if (l < 4)
-               return 0;
-       b += 4;
-       l -= 4;
-       while (l)
-       {
-               if (l < b[1] || !b[1])
-                       return 0;               // faulty
-               if (*b == mtype)
-                       return b;
-               l -= b[1];
-               b += b[1];
-       }
-       return 0;
-}
-
 // Send initial LCP ConfigReq
 void initlcp(tunnelidt t, sessionidt s)
 {
        char b[500] = {0}, *q;
 
        q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
-       if (!q) {
+       if (!q)
+       {
                LOG(1, 0, s, t, "Failed to send LCP ConfigReq.\n");
                return;
        }
@@ -919,7 +955,7 @@ void initlcp(tunnelidt t, sessionidt s)
 }
 
 // Send CCP reply
-void sendccp(tunnelidt t, sessionidt s)
+static void sendccp(tunnelidt t, sessionidt s)
 {
        char *q, b[500] = {0};