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[l2tpns.git] / ppp.c
diff --git a/ppp.c b/ppp.c
index 5ccb72a..fe9c7be 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.52 2005/05/07 13:12:26 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.61 2005/05/13 09:23:00 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -41,7 +41,7 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                LOG(1, s, t, "Short PAP %u bytes\n", l);
                STAT(tunnel_rx_errors);
                sessionshutdown(s, "Short PAP packet.", 3, 0);
-               return ;
+               return;
        }
 
        if ((hl = ntohs(*(uint16_t *) (p + 2))) > l)
@@ -49,7 +49,7 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                LOG(1, s, t, "Length mismatch PAP %u/%u\n", hl, l);
                STAT(tunnel_rx_errors);
                sessionshutdown(s, "PAP length mismatch.", 3, 0);
-               return ;
+               return;
        }
        l = hl;
 
@@ -58,7 +58,7 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                LOG(1, s, t, "Unexpected PAP code %d\n", *p);
                STAT(tunnel_rx_errors);
                sessionshutdown(s, "Unexpected PAP code.", 3, 0);
-               return ;
+               return;
        }
 
        {
@@ -157,14 +157,16 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
        {
                LOG(1, s, t, "Short CHAP %u bytes\n", l);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "Short CHAP packet.", 3, 0);
+               return;
        }
 
        if ((hl = ntohs(*(uint16_t *) (p + 2))) > l)
        {
                LOG(1, s, t, "Length mismatch CHAP %u/%u\n", hl, l);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "CHAP length mismatch.", 3, 0);
+               return;
        }
        l = hl;
 
@@ -172,20 +174,23 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
        {
                LOG(1, s, t, "Unexpected CHAP response code %d\n", *p);
                STAT(tunnel_rx_errors);
+               sessionshutdown(s, "CHAP length mismatch.", 3, 0);
                return;
        }
        if (p[1] != radius[r].id)
        {
                LOG(1, s, t, "Wrong CHAP response ID %d (should be %d) (%d)\n", p[1], radius[r].id, r);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "Unexpected CHAP response ID.", 3, 0);
+               return;
        }
 
        if (l < 5 || p[4] != 16)
        {
                LOG(1, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "Bad CHAP response length.", 3, 0);
+               return;
        }
 
        l -= 5;
@@ -194,7 +199,8 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
        {
                LOG(1, s, t, "CHAP user too long %d\n", l - 16);
                STAT(tunnel_rx_errors);
-               return ;
+               sessionshutdown(s, "CHAP username too long.", 3, 0);
+               return;
        }
 
        // Run PRE_AUTH plugins
@@ -348,7 +354,33 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
        if (*p == ConfigAck)
        {
-               LOG(3, s, t, "LCP: Discarding ConfigAck\n");
+               int x = l - 4;
+               uint8_t *o = (p + 4);
+
+               LOG(3, s, t, "LCP: ConfigAck (%d bytes)...\n", l);
+               if (config->debug > 3) dumplcp(p, l);
+
+               while (x > 2)
+               {
+                       int type = o[0];
+                       int length = o[1];
+
+                       if (length == 0 || type == 0 || x < length) break;
+                       switch (type)
+                       {
+                               case 3: // Authentication-Protocol
+                                       {
+                                               int proto = ntohs(*(uint16_t *)(o + 2));
+                                               if (proto == PPPCHAP && *(o + 4) == 5)
+                                                       sendchap(t, s);
+                                       }
+
+                                       break;
+                       }
+                       x -= length;
+                       o += length;
+               }
+
                session[s].flags |= SF_LCP_ACKED;
        }
        else if (*p == ConfigReq)
@@ -398,7 +430,6 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                                        *q++ = 6;
                                        memset(q, 0, 4); // asyncmap 0
                                        q += 4;
-                                       *((uint16_t *) (response + 2)) = htons(q - response); // LCP header length
                                        break;
 
                                case 3: // Authentication-Protocol
@@ -459,7 +490,6 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
                                                        q = a;
                                                }
 
-                                               *((uint16_t *) (response + 2)) = htons(q - response); // LCP header length
                                                break;
                                        }
                                        break;
@@ -491,32 +521,97 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
 
                                        memcpy(q, o, length);
                                        q += length;
-                                       *((uint16_t *) (response + 2)) = htons(q - response); // LCP header length
                        }
                        x -= length;
                        o += length;
                }
 
-               if (!response)
+               if (response)
                {
-                       // Send back a ConfigAck
-                       q = response = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
-                       if (!q) return;
-                       *q = ConfigAck;
+                       l = q - response; // LCP packet length
+                       *((uint16_t *) (response + 2)) = htons(l); // update header
+               }
+               else
+               {
+                       // Send packet back as ConfigAck
+                       response = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+                       if (!response) return;
+                       *response = ConfigAck;
                }
 
                LOG(3, s, t, "Sending %s\n", ppp_lcp_type(*response));
-               tunnelsend(b, l + (q - b), t);
+               tunnelsend(b, l + response - b, t);
 
                if (!(session[s].flags & SF_LCP_ACKED))
                        sendlcp(t, s, config->radius_authprefer);
        }
        else if (*p == ConfigNak)
        {
-               LOG(1, s, t, "Remote end sent a ConfigNak.  Ignoring\n");
+               int x = l - 4;
+               uint8_t *o = (p + 4);
+               int authtype = -1;
+
+               LOG(3, s, t, "LCP: ConfigNak (%d bytes)...\n", l);
                if (config->debug > 3) dumplcp(p, l);
-               // FIXME: handle MRU, authentication type
-               return;
+
+               while (x > 2)
+               {
+                       int type = o[0];
+                       int length = o[1];
+
+                       if (length == 0 || type == 0 || x < length) break;
+                       switch (type)
+                       {
+                               case 1: // Maximum-Receive-Unit
+                                       session[s].mru = ntohs(*(uint16_t *)(o + 2));
+                                       LOG(3, s, t, "    Remote requested MRU of %u\n", session[s].mru);
+                                       break;
+
+                               case 3: // Authentication-Protocol
+                                       if (authtype > 0)
+                                               break;
+
+                                       {
+                                               int proto = ntohs(*(uint16_t *)(o + 2));
+                                               if (proto == PPPPAP)
+                                               {
+                                                       authtype = config->radius_authtypes & AUTHPAP;
+                                                       LOG(3, s, t, "    Remote requested PAP authentication...%sing\n",
+                                                               authtype ? "accept" : "reject");
+                                               }
+                                               else if (proto == PPPCHAP && *(o + 4) == 5)
+                                               {
+                                                       authtype = config->radius_authtypes & AUTHCHAP;
+                                                       LOG(3, s, t, "    Remote requested CHAP authentication...%sing\n",
+                                                               authtype ? "accept" : "reject");
+                                               }
+                                               else
+                                               {
+                                                       LOG(3, s, t, "    Rejecting unsupported authentication %#4x\n",
+                                                               proto);
+                                               }
+                                       }
+
+                                       break;
+
+                               default:
+                                       LOG(2, s, t, "    Remote NAKed LCP type %u?\n", type);
+                                       break;
+                       }
+                       x -= length;
+                       o += length;
+               }
+
+               if (!authtype)
+               {
+                       sessionshutdown(s, "Unsupported authentication.", 3, 0);
+                       return;
+               }
+
+               if (authtype == -1)
+                       authtype = config->radius_authprefer;
+
+               sendlcp(t, s, authtype);
        }
        else if (*p == TerminateReq)
        {
@@ -575,7 +670,6 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
        {
                LOG(1, s, t, "Unexpected LCP code %d\n", *p);
                STAT(tunnel_rx_errors);
-               return ;
        }
 }
 
@@ -1234,7 +1328,7 @@ void sendlcp(tunnelidt t, sessionidt s, int authtype)
                return;
 
        LOG(4, s, t, "Sending LCP ConfigReq for %s\n",
-           config->radius_authprefer == AUTHCHAP ? "CHAP" : "PAP");
+           authtype == AUTHCHAP ? "CHAP" : "PAP");
 
        if (!session[s].mru)
                session[s].mru = DEFAULT_MRU;
@@ -1243,6 +1337,8 @@ void sendlcp(tunnelidt t, sessionidt s, int authtype)
        *l++ = ConfigReq;
        *l++ = (time_now % 255) + 1; // ID
 
+       l += 2; //Save space for length
+
        *l++ = 1; *l++ = 4; // Maximum-Receive-Unit (length 4)
        *(uint16_t *) l = htons(session[s].mru); l += 2;
 
for cloning use: "git clone git://git.sameswireless.fr/l2tpns.git" ; For add to your sources.list: "deb http://package.sameswifi.fr/ jessie main"