add length checks and comments to proxy LCP parsing

[l2tpns.git] / ppp.c

diff --git a/ppp.c b/ppp.c
index 6908e90..c3d00b1 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.18 2004/11/03 13:22:39 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.20 2004/11/05 02:21:55 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -194,11 +194,15 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
        {
                struct param_pre_auth packet = { &tunnel[t], &session[s], NULL, NULL, PPPCHAP, 1 };
 
-               packet.username = calloc(l - 16 + 1, 1);
-               packet.password = calloc(16, 1);
-               memcpy(packet.username, p + 16, l - 16);
+               packet.password = calloc(17, 1);
                memcpy(packet.password, p, 16);
 
+               p += 16;
+               l -= 16;
+
+               packet.username = calloc(l + 1, 1);
+               memcpy(packet.username, p, l);
+
                run_plugins(PLUGIN_PRE_AUTH, &packet);
                if (!packet.continue_auth)
                {
@@ -277,8 +281,8 @@ void dumplcp(u8 *p, int l)
                                        {
                                                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");
+                                                       proto == PPPCHAP ? "CHAP" :
+                                                       proto == PPPPAP  ? "PAP"  : "UNKNOWN");
                                        }
                                        else
                                                log(4, 0, 0, 0, "   %s odd length %d\n", lcp_types[type], length);
@@ -376,7 +380,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
                                case 3: // Authentication-Protocol
                                        {
                                                int proto = ntohs(*(u16 *)(o + 2));
-                                               if (proto == 0xC223)
+                                               if (proto == PPPCHAP)
                                                {
                                                        log(2, session[s].ip, s, t, "    Remote end is trying to do CHAP. Rejecting it.\n");
 
@@ -390,7 +394,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
                                                                *q++ = ConfigNak;
                                                        }
                                                        memcpy(q, o, length);
-                                                       *(u16 *)(q += 2) = htons(0xC023); // NAK -> Use PAP instead
+                                                       *(u16 *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead
                                                        q += length;
                                                }
                                                break;
@@ -686,6 +690,12 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
                return;
        }
 
+       if (session[s].snoop_ip && session[s].snoop_port)
+       {
+               // Snooping this session
+               snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
+       }
+
        // Add on the tun header
        p -= 4;
        *(u32 *)p = htonl(0x00000800);
@@ -703,11 +713,6 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
        session[s].pin++;
        eth_tx += l - 4;
 
-       if (session[s].snoop_ip && session[s].snoop_port)
-       {
-               // Snooping this session
-               snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
-       }
        STAT(tun_tx_packets);
        INC_STAT(tun_tx_bytes, l);
 
@@ -911,7 +916,7 @@ void initlcp(tunnelidt t, sessionidt s)
        *(u32 *)(q + 6) = htonl(session[s].magic);
        *(u8 *)(q + 10) = 3;
        *(u8 *)(q + 11) = 4;
-       *(u16 *)(q + 12) = htons(0xC023); // PAP
+       *(u16 *)(q + 12) = htons(PPPPAP); // PAP
        tunnelsend(b, 12 + 14, t);
 }