l2tpns-dont-timeshift-unidirectional-traffic.patch
[l2tpns.git] / ppp.c
diff --git a/ppp.c b/ppp.c
index de37bf2..ed30501 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.9 2004-08-02 03:38:01 fred_nerk Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.15 2004-09-19 23:19:23 fred_nerk Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -23,6 +23,8 @@ extern u32 eth_tx;
 extern time_t time_now;
 extern struct configt *config;
 
+void sendccp(tunnelidt t, sessionidt s);
+
 // Process PAP messages
 void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l)
 {
@@ -74,25 +76,27 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l)
                        return;
                }
                if (session[s].ip)
-                       *p = 2;              // ACK
+                       *p = 2;                 // ACK
                else
-                       *p = 3;              // cant authorise
+                       *p = 3;                 // cant authorise
                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)
                {
-                   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
                {
-                   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
-       {                          // set up RADIUS request
+       {
+               // set up RADIUS request
                u16 r = session[s].radius;
 
                // Run PRE_AUTH plugins
@@ -213,6 +217,7 @@ char *ppp_lcp_types[] = {
        "EchoReq",
        "EchoReply",
        "DiscardRequest",
+       "IdentRequest",
 };
 
 void dumplcp(u8 *p, int l)
@@ -246,7 +251,7 @@ void dumplcp(u8 *p, int l)
                {
                        case 1: // Maximum-Receive-Unit
                                if (length == 4)
-                               log(4, 0, 0, 0, "    %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2)));
+                                       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;
@@ -254,7 +259,7 @@ void dumplcp(u8 *p, int l)
                                {
                                        if (length == 4)
                                        {
-                                       int proto = ntohs(*(u16 *)(o + 2));
+                                               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");
@@ -273,8 +278,8 @@ void dumplcp(u8 *p, int l)
                                {
                                        if (length == 6)
                                        {
-                                       u32 magicno = ntohl(*(u32 *)(o + 2));
-                                       log(4, 0, 0, 0, "    %s %x\n", lcp_types[type], magicno);
+                                               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);
@@ -304,6 +309,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
 {
        u8 b[MAXCONTROL];
        u8 *q = NULL;
+       u32  magicno = 0;
 
 
        CSTAT(call_processlcp);
@@ -338,6 +344,10 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                                case 1: // Maximum-Receive-Unit
                                        session[s].mru = ntohs(*(u16 *)(o + 2));
                                        break;
+                               case 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));
@@ -362,27 +372,36 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                                        }
                                case 5: // Magic-Number
                                        {
-//                                             u32 magicno = ntohl(*(u32 *)(o + 2));
+                                               magicno = ntohl(*(u32 *)(o + 2));
                                                break;
                                        }
                                case 4: // Quality-Protocol
-                                       {
-//                                             u32 qp = ntohl(*(u32 *)(o + 2));
-                                               break;
-                                       }
                                case 7: // Protocol-Field-Compression
-                                       {
-//                                             u32 pfc = ntohl(*(u32 *)(o + 2));
-                                               break;
-                                       }
                                case 8: // Address-And-Control-Field-Compression
-                                       {
-//                                             u32 afc = ntohl(*(u32 *)(o + 2));
                                                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:
+                                       // 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);
-                                       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;
@@ -392,8 +411,11 @@ 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");
+                       // for  win2k L2TP clientis  and LCP renegotiation of alive session 
+                       if (magicno || l == 4) initlcp(t, s);
                        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;
                        }
@@ -418,7 +440,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
        }
        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");
@@ -434,7 +456,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
        }
        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) {
@@ -448,6 +470,23 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
        {
                // 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);
@@ -470,9 +509,11 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                return ;
        }
        if (*p == ConfigAck)
-       {                          // happy with our IPCP
+       {
+               // happy with our IPCP
                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)
@@ -480,7 +521,8 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                }
                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)
        {
@@ -488,6 +530,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                STAT(tunnel_rx_errors);
                return ;
        }
+       log(4, session[s].ip, s, t, "IPCP ConfigReq received\n");
        if (ntohs(*(u16 *) (p + 2)) > l)
        {
                log(1, 0, s, t, "Length mismatch IPCP %d/%d\n", ntohs(*(u16 *) (p + 2)), l);
@@ -497,7 +540,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
        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
        {
@@ -505,6 +548,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                u8 *i,
                *q;
 
+               l = ntohs(*(u16 *) (p + 2)); // We must use length from IPCP len field
                q = p + 4;
                i = p + l;
                while (q < i && q[1])
@@ -514,12 +558,13 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                        q += q[1];
                }
                if (q < i)
-               {                       // reject
+               {
+                       // reject
                        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;
@@ -535,30 +580,32 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                                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
                {
+                       log(4, session[s].ip, s, t, "Sending ConfigAck\n");
                        *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;
+                                       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;
+                                       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");
@@ -569,9 +616,11 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                        {
                                *(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;
                        }
@@ -588,7 +637,6 @@ void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l)
 {
        ipt ip;
 
-
        CSTAT(call_processipin);
 
        log_hex(5, "IP", p, l);
@@ -628,7 +676,7 @@ void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l)
 
        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);
@@ -698,13 +746,14 @@ void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l)
                        }
                        else
                        {
-                               *p = ConfigRej;        // reject
+                               *p = ConfigRej;         // reject
+                               sendccp(t, s);
                        }
                }
                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;
                }
@@ -728,12 +777,13 @@ void sendchap(tunnelidt t, sessionidt s)
                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();
        }
-       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;
@@ -750,11 +800,11 @@ void sendchap(tunnelidt t, sessionidt s)
                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
 }
@@ -764,7 +814,6 @@ void sendchap(tunnelidt t, sessionidt s)
 // returns start of PPP frame
 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!!
 
@@ -772,7 +821,7 @@ 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;
-       if (mtype != PPPLCP && !(session[s].l2tp_flags & SESSIONACFC))
+       if (mtype && !(session[s].l2tp_flags & SESSIONACFC))
        {
                *(u16 *) b = htons(0xFF03); // HDLC header
                b += 2;
@@ -805,7 +854,7 @@ u8 *findppp(u8 * b, u8 mtype)
        while (l)
        {
                if (l < b[1] || !b[1])
-                       return 0;            // faulty
+                       return 0;               // faulty
                if (*b == mtype)
                        return b;
                l -= b[1];
@@ -827,10 +876,26 @@ 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
-       *(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);
 }