fix parsing of protocol rej

[l2tpns.git] / ppp.c

diff --git a/ppp.c b/ppp.c
index d2708cd..005d42a 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.71 2005/08/11 06:22:11 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.76 2005/08/29 03:21:14 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -85,8 +85,7 @@ void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                LOG(3, s, t, "PAP login %s/%s\n", user, pass);
        }
 
-       r = radiusnew(s);
-       if (session[s].ip || !r)
+       if (session[s].ip || !(r = radiusnew(s)))
        {
                // respond now, either no RADIUS available or already authenticated
                uint8_t b[MAXCONTROL];
@@ -148,13 +147,6 @@ void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        CSTAT(processchap);
 
        LOG_HEX(5, "CHAP", p, l);
-       r = sess_local[s].radius;
-       if (!r)
-       {
-               LOG(1, s, t, "Unexpected CHAP message\n");
-               STAT(tunnel_rx_errors);
-               return;
-       }
 
        if (l < 4)
        {
@@ -181,6 +173,13 @@ void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                return;
        }
 
+       r = sess_local[s].radius;
+       if (!r)
+       {
+               LOG(3, s, t, "Unexpected CHAP message\n");
+               return;
+       }
+
        if (session[s].ppp.phase != Authenticate)
        {
                LOG(2, s, t, "CHAP ignored in %s phase\n", ppp_phase(session[s].ppp.phase));
@@ -428,7 +427,7 @@ static uint8_t *ppp_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
                if (!queued)
                        return 0;
 
-               *nak_sent++;
+               (*nak_sent)++;
                *queued = ConfigNak;
                queued += 4;
        }
@@ -814,16 +813,26 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        }
        else if (*p == ProtocolRej)
        {
-               if (*(uint16_t *) (p+4) == htons(PPPIPV6CP))
+               uint16_t proto = 0;
+
+               if (l > 4)
+               {
+                       proto = *(p+4);
+                       if (l > 5 && !(proto & 1))
+                       {
+                               proto <<= 8;
+                               proto |= *(p+5);
+                       }
+               }
+
+               if (proto == PPPIPV6CP)
                {
                        LOG(3, s, t, "IPv6 rejected\n");
                        change_state(s, ipv6cp, Closed);
                }
                else
                {
-                       LOG(1, s, t, "Unexpected LCP protocol reject 0x%X\n",
-                               ntohs(*(uint16_t *) (p+4)));
-                       STAT(tunnel_rx_errors);
+                       LOG(3, s, t, "LCP protocol reject: 0x%04X\n", proto);
                }
        }
        else if (*p == EchoReq)
@@ -960,8 +969,9 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                addr = htonl(session[s].ip);
                                if (memcmp(o + 2, &addr, (sizeof addr)))
                                {
+                                       uint8_t *oq = q;
                                        q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
-                                       if (!q || *response == ConfigRej)
+                                       if (!q || (q != oq && *response == ConfigRej))
                                        {
                                                sessionshutdown(s, "Can't negotiate IPCP.", 3, 0);
                                                return;