handle LCP NAK of magic-number

[l2tpns.git] / ppp.c

diff --git a/ppp.c b/ppp.c
index d7770e5..244d59a 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.87 2005/12/04 13:06:50 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.92 2006/01/19 21:00:24 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -449,6 +449,7 @@ static void ppp_code_rej(sessionidt s, tunnelidt t, uint16_t proto,
 {
        uint8_t *q;
        int mru = session[s].mru;
+       if (mru < MINMTU) mru = MINMTU;
        if (mru > size) mru = size;
 
        l += 4;
@@ -498,7 +499,9 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
        if (session[s].die) // going down...
                return;
 
-       LOG(*p == EchoReq ? 4 : 3, s, t, "LCP: recv %s\n", ppp_code(*p));
+       LOG((*p == EchoReq || *p == EchoReply) ? 4 : 3, s, t,
+               "LCP: recv %s\n", ppp_code(*p));
+
        if (config->debug > 3) dumplcp(p, l);
 
        if (*p == ConfigAck)
@@ -577,7 +580,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                case 1: // Maximum-Receive-Unit
                                        {
                                                uint16_t mru = ntohs(*(uint16_t *)(o + 2));
-                                               if (mru >= 576)
+                                               if (mru >= MINMTU)
                                                {
                                                        session[s].mru = mru;
                                                        break;
@@ -791,8 +794,19 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                                        break;
 
+                               case 5: // Magic-Number
+                                       if (*p == ConfigNak)
+                                       {
+                                               session[s].magic = ntohl(*(uint32_t *)(o + 2));
+                                               LOG(3, s, t, "    Remote requested magic-no %x\n", session[s].magic);
+                                               if (!session[s].magic) session[s].magic = time_now; // Netgear DG814 sends zero??
+                                               break;
+                                       }
+                                       // ConfigRej: fallthrough
+
                                default:
                                        LOG(2, s, t, "LCP: remote sent %s for type %u?\n", ppp_code(*p), type);
+                                       sessionshutdown(s, "Unable to negotiate LCP.", 3, 0);
                                        break;
                        }
                        x -= length;
@@ -1754,9 +1768,7 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelid
 {
        if (size < 12) // Need more space than this!!
        {
-               static int backtrace_count = 0;
                LOG(0, s, t, "makeppp buffer too small for L2TP header (size=%d)\n", size);
-               log_backtrace(backtrace_count, 5)
                return NULL;
        }
 
@@ -1779,9 +1791,7 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelid
 
        if (l + 12 > size)
        {
-               static int backtrace_count = 0;
                LOG(2, s, t, "makeppp would overflow buffer (size=%d, header+payload=%d)\n", size, l + 12);
-               log_backtrace(backtrace_count, 5)
                return NULL;
        }
 
@@ -1877,3 +1887,33 @@ void sendccp(sessionidt s, tunnelidt t)
        tunnelsend(b, (q - b) + 4 , t);
        restart_timer(s, ccp);
 }
+
+// Reject unknown/unconfigured protocols
+void protoreject(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l, uint16_t proto)
+{
+
+       uint8_t buf[MAXETHER];
+       uint8_t *q;
+       int mru = session[s].mru;
+       if (mru < MINMTU) mru = MINMTU;
+       if (mru > sizeof(buf)) mru = sizeof(buf);
+
+       l += 6;
+       if (l > mru) l = mru;
+
+       q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPLCP);
+       if (!q) return;
+
+       *q = ProtocolRej;
+       *(q + 1) = ++sess_local[s].lcp_ident;
+       *(uint16_t *)(q + 2) = htons(l);
+       *(uint16_t *)(q + 4) = htons(proto);
+       memcpy(q + 6, p, l - 6);
+
+       if (proto == PPPIPV6CP)
+               LOG(3, s, t, "LCP: send ProtocolRej (IPV6CP: not configured)\n");
+       else
+               LOG(2, s, t, "LCP: sent ProtocolRej (0x%04X: unsupported)\n", proto);
+
+       tunnelsend(buf, l + (q - buf), t);
+}