projects / l2tpns.git / blobdiff
? search:
summary | shortlog | log | commit | commitdiff | tree
raw | inline | side by side
retain subdomain of hostname if any
[l2tpns.git] / ppp.c
diff --git a/ppp.c b/ppp.c
index a88add9..6908e90 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.7 2004/07/08 16:54:35 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.18 2004/11/03 13:22:39 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
 
 #include <stdio.h>
 #include <string.h>
@@ -23,12 +23,14 @@ extern u32 eth_tx;
 extern time_t time_now;
 extern struct configt *config;
 
 extern time_t time_now;
 extern struct configt *config;
 
+void sendccp(tunnelidt t, sessionidt s);
+
 // Process PAP messages
 // Process PAP messages
-void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
        char user[129];
        char pass[129];
 {
        char user[129];
        char pass[129];
-
+       u16 hl;
 
        CSTAT(call_processpap);
 
 
        CSTAT(call_processpap);
 
@@ -39,18 +41,22 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l)
                STAT(tunnel_rx_errors);
                return ;
        }
                STAT(tunnel_rx_errors);
                return ;
        }
-       if (*p != 1)
+
+       if ((hl = ntohs(*(u16 *) (p + 2))) > l)
        {
        {
-               log(1, 0, s, t, "Unexpected PAP code %d\n", *p);
+               log(1, 0, s, t, "Length mismatch PAP %u/%u\n", hl, l);
                STAT(tunnel_rx_errors);
                return ;
        }
                STAT(tunnel_rx_errors);
                return ;
        }
-       if (ntohs(*(u16 *) (p + 2)) > l)
+       l = hl;
+
+       if (*p != 1)
        {
        {
-               log(1, 0, s, t, "Length mismatch PAP %d/%d\n", ntohs(*(u16 *) (p + 2)), l);
+               log(1, 0, s, t, "Unexpected PAP code %d\n", *p);
                STAT(tunnel_rx_errors);
                return ;
        }
                STAT(tunnel_rx_errors);
                return ;
        }
+
        {
                u8 *b = p;
                b += 4;
        {
                u8 *b = p;
                b += 4;
@@ -74,25 +80,27 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l)
                        return;
                }
                if (session[s].ip)
                        return;
                }
                if (session[s].ip)
-                       *p = 2;              // ACK
+                       *p = 2;                 // ACK
                else
                else
-                       *p = 3;              // cant authorise
+                       *p = 3;                 // cant authorise
                p[1] = id;
                p[1] = id;
-               *(u16 *) (p + 2) = htons(5); // length
-               p[4] = 0;               // no message
+               *(u16 *) (p + 2) = htons(5);    // length
+               p[4] = 0;                       // no message
                if (session[s].ip)
                {
                if (session[s].ip)
                {
-                   log(3, session[s].ip, s, t, "%d Already an IP allocated: %s (%d)\n", getpid(), inet_toa(htonl(session[s].ip)), session[s].ip_pool_index);
+                       log(3, session[s].ip, s, t, "%d Already an IP allocated: %s (%d)\n", getpid(), inet_toa(htonl(session[s].ip)), session[s].ip_pool_index);
+                       session[s].flags &= ~SF_IPCP_ACKED;
                }
                else
                {
                }
                else
                {
-                   log(1, 0, s, t, "No radius session available to authenticate session...\n");
+                       log(1, 0, s, t, "No radius session available to authenticate session...\n");
                }
                log(3, 0, s, t, "Fallback response to PAP (%s)\n", (session[s].ip) ? "ACK" : "NAK");
                tunnelsend(b, 5 + (p - b), t); // send it
        }
        else
                }
                log(3, 0, s, t, "Fallback response to PAP (%s)\n", (session[s].ip) ? "ACK" : "NAK");
                tunnelsend(b, 5 + (p - b), t); // send it
        }
        else
-       {                          // set up RADIUS request
+       {
+               // set up RADIUS request
                u16 r = session[s].radius;
 
                // Run PRE_AUTH plugins
                u16 r = session[s].radius;
 
                // Run PRE_AUTH plugins
@@ -119,11 +127,10 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l)
 }
 
 // Process CHAP messages
 }
 
 // Process CHAP messages
-void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
        u16 r;
 {
        u16 r;
-       u16 len;
-
+       u16 hl;
 
        CSTAT(call_processchap);
 
 
        CSTAT(call_processchap);
 
@@ -138,6 +145,22 @@ void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l)
                STAT(tunnel_rx_errors);
                return;
        }
                STAT(tunnel_rx_errors);
                return;
        }
+
+       if (l < 4)
+       {
+               log(1, 0, s, t, "Short CHAP %u bytes\n", l);
+               STAT(tunnel_rx_errors);
+               return ;
+       }
+
+       if ((hl = ntohs(*(u16 *) (p + 2))) > l)
+       {
+               log(1, 0, s, t, "Length mismatch CHAP %u/%u\n", hl, l);
+               STAT(tunnel_rx_errors);
+               return ;
+       }
+       l = hl;
+
        if (*p != 2)
        {
                log(1, 0, s, t, "Unexpected CHAP response code %d\n", *p);
        if (*p != 2)
        {
                log(1, 0, s, t, "Unexpected CHAP response code %d\n", *p);
@@ -150,22 +173,19 @@ void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l)
                STAT(tunnel_rx_errors);
                return ;
        }
                STAT(tunnel_rx_errors);
                return ;
        }
-       len = ntohs(*(u16 *) (p + 2));
-       if (len > l)
-       {
-               log(1, 0, s, t, "Bad CHAP length %d\n", len);
-               STAT(tunnel_rx_errors);
-               return ;
-       }
-       if (p[4] != 16)
+
+       if (l < 5 || p[4] != 16)
        {
        {
-               log(1, 0, s, t, "Bad CHAP response length %d\n", p[4]);
+               log(1, 0, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]);
                STAT(tunnel_rx_errors);
                return ;
        }
                STAT(tunnel_rx_errors);
                return ;
        }
-       if (len - 21 >= sizeof(session[s].user))
+
+       l -= 5;
+       p += 5;
+       if (l < 16 || l - 16 >= sizeof(session[s].user))
        {
        {
-               log(1, 0, s, t, "CHAP user too long %d\n", len - 21);
+               log(1, 0, s, t, "CHAP user too long %d\n", l - 16);
                STAT(tunnel_rx_errors);
                return ;
        }
                STAT(tunnel_rx_errors);
                return ;
        }
@@ -174,10 +194,10 @@ void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l)
        {
                struct param_pre_auth packet = { &tunnel[t], &session[s], NULL, NULL, PPPCHAP, 1 };
 
        {
                struct param_pre_auth packet = { &tunnel[t], &session[s], NULL, NULL, PPPCHAP, 1 };
 
-               packet.username = calloc(len-20, 1);
+               packet.username = calloc(l - 16 + 1, 1);
                packet.password = calloc(16, 1);
                packet.password = calloc(16, 1);
-               memcpy(packet.username, p + 21, len - 21);
-               memcpy(packet.password, p + 5, 16);
+               memcpy(packet.username, p + 16, l - 16);
+               memcpy(packet.password, p, 16);
 
                run_plugins(PLUGIN_PRE_AUTH, &packet);
                if (!packet.continue_auth)
 
                run_plugins(PLUGIN_PRE_AUTH, &packet);
                if (!packet.continue_auth)
@@ -213,11 +233,12 @@ char *ppp_lcp_types[] = {
        "EchoReq",
        "EchoReply",
        "DiscardRequest",
        "EchoReq",
        "EchoReply",
        "DiscardRequest",
+       "IdentRequest",
 };
 
 void dumplcp(u8 *p, int l)
 {
 };
 
 void dumplcp(u8 *p, int l)
 {
-       signed int x = l - 4;
+       int x = l - 4;
        u8 *o = (p + 4);
 
        log_hex(5, "PPP LCP Packet", p, l);
        u8 *o = (p + 4);
 
        log_hex(5, "PPP LCP Packet", p, l);
@@ -230,9 +251,9 @@ void dumplcp(u8 *p, int l)
        {
                int type = o[0];
                int length = o[1];
        {
                int type = o[0];
                int length = o[1];
-               if (length == 0)
+               if (length < 2)
                {
                {
-                       log(4, 0, 0, 0, "       Option length is 0...\n");
+                       log(4, 0, 0, 0, "       Option length is %d...\n", length);
                        break;
                }
                if (type == 0)
                        break;
                }
                if (type == 0)
@@ -245,13 +266,22 @@ void dumplcp(u8 *p, int l)
                switch (type)
                {
                        case 1: // Maximum-Receive-Unit
                switch (type)
                {
                        case 1: // Maximum-Receive-Unit
-                               log(4, 0, 0, 0, "    %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2)));
+                               if (length == 4)
+                                       log(4, 0, 0, 0, "    %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2)));
+                               else
+                                       log(4, 0, 0, 0, "    %s odd length %d\n", lcp_types[type], length);
                                break;
                        case 3: // Authentication-Protocol
                                {
                                break;
                        case 3: // Authentication-Protocol
                                {
-                                       int proto = ntohs(*(u16 *)(o + 2));
-                                       log(4, 0, 0, 0, "    %s %s\n", lcp_types[type],
-                                                       proto == 0xC223 ? "CHAP" : "PAP");
+                                       if (length == 4)
+                                       {
+                                               int proto = ntohs(*(u16 *)(o + 2));
+                                               log(4, 0, 0, 0, "   %s 0x%x (%s)\n", lcp_types[type], proto,
+                                                       proto == 0xC223 ? "CHAP" :
+                                                       proto == 0xC023 ? "PAP"  : "UNKNOWN");
+                                       }
+                                       else
+                                               log(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
                                        break;
                                }
                        case 4: // Quality-Protocol
                                        break;
                                }
                        case 4: // Quality-Protocol
@@ -262,20 +292,23 @@ void dumplcp(u8 *p, int l)
                                }
                        case 5: // Magic-Number
                                {
                                }
                        case 5: // Magic-Number
                                {
-                                       u32 magicno = ntohl(*(u32 *)(o + 2));
-                                       log(4, 0, 0, 0, "    %s %x\n", lcp_types[type], magicno);
+                                       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;
                                }
                        case 7: // Protocol-Field-Compression
                                {
                                        break;
                                }
                        case 7: // Protocol-Field-Compression
                                {
-                                       u32 pfc = ntohl(*(u32 *)(o + 2));
-                                       log(4, 0, 0, 0, "    %s %x\n", lcp_types[type], pfc);
+                                       log(4, 0, 0, 0, "    %s\n", lcp_types[type]);
                                        break;
                                }
                        case 8: // Address-And-Control-Field-Compression
                                {
                                        break;
                                }
                        case 8: // Address-And-Control-Field-Compression
                                {
-                                       u32 afc = ntohl(*(u32 *)(o + 2));
-                                       log(4, 0, 0, 0, "    %s %x\n", lcp_types[type], afc);
+                                       log(4, 0, 0, 0, "    %s\n", lcp_types[type]);
                                        break;
                                }
                        default:
                                        break;
                                }
                        default:
@@ -288,11 +321,12 @@ void dumplcp(u8 *p, int l)
 }
 
 // Process LCP messages
 }
 
 // Process LCP messages
-void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
        u8 b[MAXCONTROL];
        u8 *q = NULL;
 {
        u8 b[MAXCONTROL];
        u8 *q = NULL;
-
+       u32 magicno = 0;
+       u16 hl;
 
        CSTAT(call_processlcp);
 
 
        CSTAT(call_processlcp);
 
@@ -303,17 +337,27 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                STAT(tunnel_rx_errors);
                return ;
        }
                STAT(tunnel_rx_errors);
                return ;
        }
+
+       if ((hl = ntohs(*(u16 *) (p + 2))) > l)
+       {
+               log(1, 0, s, t, "Length mismatch LCP %u/%u\n", hl, l);
+               STAT(tunnel_rx_errors);
+               return ;
+       }
+       l = hl;
+
        if (*p == ConfigAck)
        {
                log(3, session[s].ip, s, t, "LCP: Discarding ConfigAck\n");
        if (*p == ConfigAck)
        {
                log(3, session[s].ip, s, t, "LCP: Discarding ConfigAck\n");
+               session[s].flags |= SESSIONLCPACK;
        }
        else if (*p == ConfigReq)
        {
        }
        else if (*p == ConfigReq)
        {
-               signed int x = l - 4;
+               int x = l - 4;
                u8 *o = (p + 4);
 
                log(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l);
                u8 *o = (p + 4);
 
                log(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l);
-               dumplcp(p, l);
+               if (config->debug > 3) dumplcp(p, l);
 
                while (x > 2)
                {
 
                while (x > 2)
                {
@@ -325,6 +369,10 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                                case 1: // Maximum-Receive-Unit
                                        session[s].mru = ntohs(*(u16 *)(o + 2));
                                        break;
                                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]) );
+                                       break;
                                case 3: // Authentication-Protocol
                                        {
                                                int proto = ntohs(*(u16 *)(o + 2));
                                case 3: // Authentication-Protocol
                                        {
                                                int proto = ntohs(*(u16 *)(o + 2));
@@ -349,27 +397,36 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                                        }
                                case 5: // Magic-Number
                                        {
                                        }
                                case 5: // Magic-Number
                                        {
-//                                             u32 magicno = ntohl(*(u32 *)(o + 2));
+                                               magicno = ntohl(*(u32 *)(o + 2));
                                                break;
                                        }
                                case 4: // Quality-Protocol
                                                break;
                                        }
                                case 4: // Quality-Protocol
-                                       {
-//                                             u32 qp = ntohl(*(u32 *)(o + 2));
-                                               break;
-                                       }
                                case 7: // Protocol-Field-Compression
                                case 7: // Protocol-Field-Compression
-                                       {
-//                                             u32 pfc = ntohl(*(u32 *)(o + 2));
-                                               break;
-                                       }
                                case 8: // Address-And-Control-Field-Compression
                                case 8: // Address-And-Control-Field-Compression
-                                       {
-//                                             u32 afc = ntohl(*(u32 *)(o + 2));
                                                break;
                                                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;
                                        }
                                        }
+
                                default:
                                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);
                                        log(2, session[s].ip, s, t, "    Unknown PPP LCP Option type %d\n", type);
-                                       break;
+                                       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;
                        }
                        x -= length;
                        o += length;
                        }
                        x -= length;
                        o += length;
@@ -379,8 +436,11 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                {
                        // Send back a ConfigAck
                        log(3, session[s].ip, s, t, "ConfigReq accepted, sending as Ack\n");
                {
                        // Send back a ConfigAck
                        log(3, session[s].ip, s, t, "ConfigReq accepted, sending as Ack\n");
+                       // for win2k L2TP clients and LCP renegotiation of alive session
+                       if (magicno || l == 4 || (session[s].mru && l == 8)) initlcp(t, s);
                        q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
                        q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-                       if (!q) {
+                       if (!q)
+                       {
                                log(3, session[s].ip, s, t, " failed to create packet.\n");
                                return;
                        }
                                log(3, session[s].ip, s, t, " failed to create packet.\n");
                                return;
                        }
@@ -392,25 +452,20 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                        // Already built a ConfigNak... send it
                        log(3, session[s].ip, s, t, "Sending ConfigNak\n");
                        tunnelsend(b, l + (q - b), t);
                        // Already built a ConfigNak... send it
                        log(3, session[s].ip, s, t, "Sending ConfigNak\n");
                        tunnelsend(b, l + (q - b), t);
-
-                       log(3, session[s].ip, s, t, "Sending ConfigReq, requesting PAP login\n");
-                       q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
-                       *q++ = ConfigReq;
-                       *(u8 *)(q++) = 3;
-                       *(u8 *)(q++) = 4;
-                       *(u16 *)(q += 2) = htons(0xC023);
-                       tunnelsend(b, l + (q - b), t);
                }
                }
+
+               if (!(session[s].flags & SESSIONLCPACK))
+                       initlcp(t, s);
        }
        else if (*p == ConfigNak)
        {
                log(1, session[s].ip, s, t, "Remote end sent a ConfigNak. Ignoring\n");
        }
        else if (*p == ConfigNak)
        {
                log(1, session[s].ip, s, t, "Remote end sent a ConfigNak. Ignoring\n");
-               dumplcp(p, l);
+               if (config->debug > 3) dumplcp(p, l);
                return ;
        }
        else if (*p == TerminateReq)
        {
                return ;
        }
        else if (*p == TerminateReq)
        {
-               *p = TerminateAck;     // close
+               *p = TerminateAck;      // close
                q = makeppp(b, sizeof(b),  p, l, t, s, PPPLCP);
                if (!q) {
                        log(3, session[s].ip, s, t, "Failed to create PPP packet in processlcp.\n");
                q = makeppp(b, sizeof(b),  p, l, t, s, PPPLCP);
                if (!q) {
                        log(3, session[s].ip, s, t, "Failed to create PPP packet in processlcp.\n");
@@ -420,13 +475,13 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                sessionshutdown(s, "Remote end closed connection.");
                tunnelsend(b, l + (q - b), t); // send it
        }
                sessionshutdown(s, "Remote end closed connection.");
                tunnelsend(b, l + (q - b), t); // send it
        }
-       else if (*p == TerminateReq)
+       else if (*p == TerminateAck)
        {
        {
-               sessionshutdown(s, "Remote end closed connection.");
+               sessionshutdown(s, "Connection closed.");
        }
        else if (*p == EchoReq)
        {
        }
        else if (*p == EchoReq)
        {
-               *p = EchoReply;      // reply
+               *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) {
                *(u32 *) (p + 4) = htonl(session[s].magic); // our magic number
                q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
                if (!q) {
@@ -440,6 +495,23 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
        {
                // Ignore it, last_packet time is set earlier than this.
        }
        {
                // Ignore it, last_packet time is set earlier than this.
        }
+       else if (*p == IdentRequest)
+       {
+               *p = CodeRej;
+               if (l > MAXCONTROL)
+               {
+                       log(1, 0, s, t, "Truncated Ident Packet (length=%d) to 1400 bytes\n", l);
+                       l = 1400;
+               }
+               q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+               if (!q)
+               {
+                       log(3, session[s].ip, s, t, "Failed to create IdentRej.\n");
+                       return;
+               }
+               log_hex(5, "LCPIdentRej", q, l + 4);
+               tunnelsend(b, 12 + 4 + l, t);
+       }
        else
        {
                log(1, session[s].ip, s, t, "Unexpected LCP code %d\n", *p);
        else
        {
                log(1, session[s].ip, s, t, "Unexpected LCP code %d\n", *p);
@@ -449,8 +521,9 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
 }
 
 // Process IPCP messages
 }
 
 // Process IPCP messages
-void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
 {
+       u16 hl;
 
        CSTAT(call_processipcp);
 
 
        CSTAT(call_processipcp);
 
@@ -461,10 +534,21 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                STAT(tunnel_rx_errors);
                return ;
        }
                STAT(tunnel_rx_errors);
                return ;
        }
+
+       if ((hl = ntohs(*(u16 *) (p + 2))) > l)
+       {
+               log(1, 0, s, t, "Length mismatch IPCP %u/%u\n", hl, l);
+               STAT(tunnel_rx_errors);
+               return ;
+       }
+       l = hl;
+
        if (*p == ConfigAck)
        if (*p == ConfigAck)
-       {                          // happy with our IPCP
+       {
+               // happy with our IPCP
                u16 r = session[s].radius;
                u16 r = session[s].radius;
-               if ((!r || radius[r].state == RADIUSIPCP) && !session[s].walled_garden) {
+               if ((!r || radius[r].state == RADIUSIPCP) && !session[s].walled_garden)
+               {
                        if (!r)
                                r = radiusnew(s);
                        if (r)
                        if (!r)
                                r = radiusnew(s);
                        if (r)
@@ -472,7 +556,8 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                }
                session[s].flags |= SF_IPCP_ACKED;
 
                }
                session[s].flags |= SF_IPCP_ACKED;
 
-               return ;                 // done
+               log(3, session[s].ip, s, t, "IPCP Acked, session is now active\n");
+               return;
        }
        if (*p != ConfigReq)
        {
        }
        if (*p != ConfigReq)
        {
@@ -480,16 +565,12 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                STAT(tunnel_rx_errors);
                return ;
        }
                STAT(tunnel_rx_errors);
                return ;
        }
-       if (ntohs(*(u16 *) (p + 2)) > l)
-       {
-               log(1, 0, s, t, "Length mismatch IPCP %d/%d\n", ntohs(*(u16 *) (p + 2)), l);
-               STAT(tunnel_rx_errors);
-               return ;
-       }
+       log(4, session[s].ip, s, t, "IPCP ConfigReq received\n");
+
        if (!session[s].ip)
        {
                log(3, 0, s, t, "Waiting on radius reply\n");
        if (!session[s].ip)
        {
                log(3, 0, s, t, "Waiting on radius reply\n");
-               return ;                   // have to wait on RADIUS reply
+               return;                 // have to wait on RADIUS reply
        }
        // form a config reply quoting the IP in the session
        {
        }
        // form a config reply quoting the IP in the session
        {
@@ -506,12 +587,13 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                        q += q[1];
                }
                if (q < i)
                        q += q[1];
                }
                if (q < i)
-               {                       // reject
+               {
+                       // reject
                        u16 n = 4;
                        i = p + l;
                        u16 n = 4;
                        i = p + l;
-                       q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP);
-                       if (!q) {
-                               log(2, 0, s, t, "Failed to send IPCP.\n");
+                       if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
+                       {
+                               log(2, 0, s, t, "Failed to send IPCP ConfigRej\n");
                                return;
                        }
                        *q = ConfigRej;
                                return;
                        }
                        *q = ConfigRej;
@@ -527,30 +609,32 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                                p += p[1];
                        }
                        *(u16 *) (q + 2) = htons(n);
                                p += p[1];
                        }
                        *(u16 *) (q + 2) = htons(n);
+                       log(4, session[s].ip, s, t, "Sending ConfigRej\n");
                        tunnelsend(b, n + (q - b), t); // send it
                }
                else
                {
                        tunnelsend(b, n + (q - b), t); // send it
                }
                else
                {
+                       log(4, session[s].ip, s, t, "Sending ConfigAck\n");
                        *p = ConfigAck;
                        *p = ConfigAck;
-                       i = findppp(p, 0x81); // Primary DNS address
-                       if (i)
+                       if ((i = findppp(p, 0x81))) // Primary DNS address
                        {
                                if (*(u32 *) (i + 2) != htonl(session[s].dns1))
                                {
                                        *(u32 *) (i + 2) = htonl(session[s].dns1);
                                        *p = ConfigNak;
                        {
                                if (*(u32 *) (i + 2) != htonl(session[s].dns1))
                                {
                                        *(u32 *) (i + 2) = htonl(session[s].dns1);
                                        *p = ConfigNak;
+                                       log(5, session[s].ip, s, t, "   DNS1 = %s\n", inet_toa(session[s].dns1));
                                }
                        }
                                }
                        }
-                       i = findppp(p, 0x83); // Secondary DNS address (TBA, is it)
-                       if (i)
+                       if ((i = findppp(p, 0x83))) // Secondary DNS address (TBA, is it)
                        {
                                if (*(u32 *) (i + 2) != htonl(session[s].dns2))
                                {
                                        *(u32 *) (i + 2) = htonl(session[s].dns2);
                                        *p = ConfigNak;
                        {
                                if (*(u32 *) (i + 2) != htonl(session[s].dns2))
                                {
                                        *(u32 *) (i + 2) = htonl(session[s].dns2);
                                        *p = ConfigNak;
+                                       log(5, session[s].ip, s, t, "   DNS2 = %s\n", inet_toa(session[s].dns1));
                                }
                        }
                                }
                        }
-                       i = findppp(p, 3);   // IP address
+                       i = findppp(p, 3);              // IP address
                        if (!i || i[1] != 6)
                        {
                                log(1, 0, s, t, "No IP in IPCP request\n");
                        if (!i || i[1] != 6)
                        {
                                log(1, 0, s, t, "No IP in IPCP request\n");
@@ -561,9 +645,11 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                        {
                                *(u32 *) (i + 2) = htonl(session[s].ip);
                                *p = ConfigNak;
                        {
                                *(u32 *) (i + 2) = htonl(session[s].ip);
                                *p = ConfigNak;
+                               log(4, session[s].ip, s, t, " No, a ConfigNak, client is requesting IP - sending %s\n",
+                                               inet_toa(htonl(session[s].ip)));
                        }
                        }
-                       q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP);
-                       if (!q) {
+                       if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
+                       {
                                log(2, 0, s, t, " Failed to send IPCP packet.\n");
                                return;
                        }
                                log(2, 0, s, t, " Failed to send IPCP packet.\n");
                                return;
                        }
@@ -576,11 +662,10 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
 //
 // This MUST be called with at least 4 byte behind 'p'.
 // (i.e. this routine writes to p[-4]).
 //
 // This MUST be called with at least 4 byte behind 'p'.
 // (i.e. this routine writes to p[-4]).
-void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
        ipt ip;
 
 {
        ipt ip;
 
-
        CSTAT(call_processipin);
 
        log_hex(5, "IP", p, l);
        CSTAT(call_processipin);
 
        log_hex(5, "IP", p, l);
@@ -620,7 +705,7 @@ void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l)
 
        if (session[s].snoop_ip && session[s].snoop_port)
        {
 
        if (session[s].snoop_ip && session[s].snoop_port)
        {
-               // Snooping this session, send it to ASIO
+               // Snooping this session
                snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
        }
        STAT(tun_tx_packets);
                snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
        }
        STAT(tun_tx_packets);
@@ -666,7 +751,7 @@ void send_ipin(sessionidt s, u8 *buf, int len)
 
 
 // Process LCP messages
 
 
 // Process LCP messages
-void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processccp(tunnelidt t, sessionidt s, u8 *p, u16 l)
 {
 
        CSTAT(call_processccp);
 {
 
        CSTAT(call_processccp);
@@ -674,7 +759,7 @@ void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l)
        log_hex(5, "CCP", p, l);
        if (l < 2 || (*p != ConfigReq && *p != TerminateReq))
        {
        log_hex(5, "CCP", p, l);
        if (l < 2 || (*p != ConfigReq && *p != TerminateReq))
        {
-               log(1, 0, s, t, "Unexpecetd CCP request code %d\n", *p);
+               log(1, 0, s, t, "Unexpected CCP request code %d\n", *p);
                STAT(tunnel_rx_errors);
                return ;
        }
                STAT(tunnel_rx_errors);
                return ;
        }
@@ -690,13 +775,14 @@ void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                        }
                        else
                        {
                        }
                        else
                        {
-                               *p = ConfigRej;        // reject
+                               *p = ConfigRej;         // reject
+                               sendccp(t, s);
                        }
                }
                else
                        }
                }
                else
-                       *p = TerminateAck;     // close
-               q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP);
-               if (!q) {
+                       *p = TerminateAck;              // close
+               if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP)))
+               {
                        log(1,0,0,0, "Failed to send CCP packet.\n");   
                        return;
                }
                        log(1,0,0,0, "Failed to send CCP packet.\n");   
                        return;
                }
@@ -720,12 +806,13 @@ void sendchap(tunnelidt t, sessionidt s)
                return ;
        }
        log(1, 0, s, t, "Send CHAP challenge\n");
                return ;
        }
        log(1, 0, s, t, "Send CHAP challenge\n");
-       {                            // new challenge
+       {
+               // new challenge
                int n;
                for (n = 0; n < 15; n++)
                        radius[r].auth[n] = rand();
        }
                int n;
                for (n = 0; n < 15; n++)
                        radius[r].auth[n] = rand();
        }
-       radius[r].chap = 1;          // CHAP not PAP
+       radius[r].chap = 1;             // CHAP not PAP
        radius[r].id++;
        if (radius[r].state != RADIUSCHAP)
                radius[r].try = 0;
        radius[r].id++;
        if (radius[r].state != RADIUSCHAP)
                radius[r].try = 0;
@@ -742,11 +829,11 @@ void sendchap(tunnelidt t, sessionidt s)
                log(1, 0, s, t, "failed to send CHAP challenge.\n");
                return;
        }
                log(1, 0, s, t, "failed to send CHAP challenge.\n");
                return;
        }
-       *q = 1;                      // challenhe
-       q[1] = radius[r].id;         // ID
-       q[4] = 16;                   // length
-       memcpy(q + 5, radius[r].auth, 16); // challenge
-       strcpy(q + 21, hostname);    // our name
+       *q = 1;                                 // challenge
+       q[1] = radius[r].id;                    // ID
+       q[4] = 16;                              // length
+       memcpy(q + 5, radius[r].auth, 16);      // challenge
+       strcpy(q + 21, hostname);               // our name
        *(u16 *) (q + 2) = htons(strlen(hostname) + 21); // length
        tunnelsend(b, strlen(hostname) + 21 + (q - b), t); // send it
 }
        *(u16 *) (q + 2) = htons(strlen(hostname) + 21); // length
        tunnelsend(b, strlen(hostname) + 21 + (q - b), t); // send it
 }
@@ -754,9 +841,8 @@ void sendchap(tunnelidt t, sessionidt s)
 // fill in a L2TP message with a PPP frame,
 // copies existing PPP message and changes magic number if seen
 // returns start of PPP frame
 // fill in a L2TP message with a PPP frame,
 // copies existing PPP message and changes magic number if seen
 // returns start of PPP frame
-u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype)
+u8 *makeppp(u8 *b, int size, u8 *p, int l, tunnelidt t, sessionidt s, u16 mtype)
 {
 {
-
        if (size < 12)
                return NULL;    // Need more space than this!!
 
        if (size < 12)
                return NULL;    // Need more space than this!!
 
@@ -764,7 +850,7 @@ u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtyp
        *(u16 *) (b + 2) = htons(tunnel[t].far); // tunnel
        *(u16 *) (b + 4) = htons(session[s].far); // session
        b += 6;
        *(u16 *) (b + 2) = htons(tunnel[t].far); // tunnel
        *(u16 *) (b + 4) = htons(session[s].far); // session
        b += 6;
-       if (mtype != PPPLCP && !(session[s].l2tp_flags & SESSIONACFC))
+       if (mtype == PPPLCP || !(session[s].l2tp_flags & SESSIONACFC))
        {
                *(u16 *) b = htons(0xFF03); // HDLC header
                b += 2;
        {
                *(u16 *) b = htons(0xFF03); // HDLC header
                b += 2;
@@ -787,7 +873,7 @@ u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtyp
 }
 
 // find a PPP option, returns point to option, or 0 if not found
 }
 
 // find a PPP option, returns point to option, or 0 if not found
-u8 *findppp(u8 * b, u8 mtype)
+u8 *findppp(u8 *b, u8 mtype)
 {
        u16 l = ntohs(*(u16 *) (b + 2));
        if (l < 4)
 {
        u16 l = ntohs(*(u16 *) (b + 2));
        if (l < 4)
@@ -797,7 +883,7 @@ u8 *findppp(u8 * b, u8 mtype)
        while (l)
        {
                if (l < b[1] || !b[1])
        while (l)
        {
                if (l < b[1] || !b[1])
-                       return 0;            // faulty
+                       return 0;               // faulty
                if (*b == mtype)
                        return b;
                l -= b[1];
                if (*b == mtype)
                        return b;
                l -= b[1];
@@ -819,10 +905,26 @@ void initlcp(tunnelidt t, sessionidt s)
        log(4, 0, s, t, "Sending LCP ConfigReq for PAP\n");
        *q = ConfigReq;
        *(u8 *)(q + 1) = (time_now % 255) + 1; // ID
        log(4, 0, s, t, "Sending LCP ConfigReq for PAP\n");
        *q = ConfigReq;
        *(u8 *)(q + 1) = (time_now % 255) + 1; // ID
-       *(u16 *)(q + 2) = htons(8); // Length
-       *(u8 *)(q + 4) = 3;
-       *(u8 *)(q + 5) = 4;
-       *(u16 *)(q + 6) = htons(0xC023); // PAP
-       tunnelsend(b, 12 + 8, t);
+       *(u16 *)(q + 2) = htons(14); // Length
+       *(u8 *)(q + 4) = 5;
+       *(u8 *)(q + 5) = 6;
+       *(u32 *)(q + 6) = htonl(session[s].magic);
+       *(u8 *)(q + 10) = 3;
+       *(u8 *)(q + 11) = 4;
+       *(u16 *)(q + 12) = htons(0xC023); // PAP
+       tunnelsend(b, 12 + 14, t);
+}
+
+// Send CCP reply
+void sendccp(tunnelidt t, sessionidt s)
+{
+       char *q, b[500] = {0};
+
+       q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP);
+       *q = ConfigReq;
+       *(u8 *)(q + 1) = (time_now % 255) + 1; // ID
+       *(u16 *)(q + 2) = htons(4); // Length
+       log_hex(5, "PPPCCP", q, 4);
+       tunnelsend(b, (q - b) + 4 , t);
 }
 
 }
 
for cloning use: "git clone git://git.sameswireless.fr/l2tpns.git" ; For add to your sources.list: "deb http://package.sameswifi.fr/ jessie main"