X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/abbc5c5fcef36f53fe0367d4f0877c1f3c05ff90..4da95975031c20cb0caf210a3bd78ca8f9963dd6:/ppp.c diff --git a/ppp.c b/ppp.c index 236e3a7..6f5bacf 100644 --- a/ppp.c +++ b/ppp.c @@ -1,6 +1,6 @@ // L2TPNS PPP Stuff -char const *cvs_id_ppp = "$Id: ppp.c,v 1.13 2004-08-26 04:44:26 fred_nerk Exp $"; +char const *cvs_id_ppp = "$Id: ppp.c,v 1.20 2004-11-05 02:21:55 bodea Exp $"; #include #include @@ -26,11 +26,11 @@ extern struct configt *config; void sendccp(tunnelidt t, sessionidt s); // Process PAP messages -void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) +void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l) { char user[129]; char pass[129]; - + u16 hl; CSTAT(call_processpap); @@ -41,18 +41,22 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) STAT(tunnel_rx_errors); return ; } - if (*p != 1) + + if ((hl = ntohs(*(u16 *) (p + 2))) > l) { - log(1, 0, s, t, "Unexpected PAP code %d\n", *p); + log(1, 0, s, t, "Length mismatch PAP %u/%u\n", hl, l); STAT(tunnel_rx_errors); return ; } - if (ntohs(*(u16 *) (p + 2)) > l) + l = hl; + + if (*p != 1) { - log(1, 0, s, t, "Length mismatch PAP %d/%d\n", ntohs(*(u16 *) (p + 2)), l); + log(1, 0, s, t, "Unexpected PAP code %d\n", *p); STAT(tunnel_rx_errors); return ; } + { u8 *b = p; b += 4; @@ -123,11 +127,10 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) } // Process CHAP messages -void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l) +void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l) { u16 r; - u16 len; - + u16 hl; CSTAT(call_processchap); @@ -142,6 +145,22 @@ void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l) STAT(tunnel_rx_errors); return; } + + if (l < 4) + { + log(1, 0, s, t, "Short CHAP %u bytes\n", l); + STAT(tunnel_rx_errors); + return ; + } + + if ((hl = ntohs(*(u16 *) (p + 2))) > l) + { + log(1, 0, s, t, "Length mismatch CHAP %u/%u\n", hl, l); + STAT(tunnel_rx_errors); + return ; + } + l = hl; + if (*p != 2) { log(1, 0, s, t, "Unexpected CHAP response code %d\n", *p); @@ -154,22 +173,19 @@ void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l) STAT(tunnel_rx_errors); return ; } - len = ntohs(*(u16 *) (p + 2)); - if (len > l) - { - log(1, 0, s, t, "Bad CHAP length %d\n", len); - STAT(tunnel_rx_errors); - return ; - } - if (p[4] != 16) + + if (l < 5 || p[4] != 16) { - log(1, 0, s, t, "Bad CHAP response length %d\n", p[4]); + log(1, 0, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]); STAT(tunnel_rx_errors); return ; } - if (len - 21 >= sizeof(session[s].user)) + + l -= 5; + p += 5; + if (l < 16 || l - 16 >= sizeof(session[s].user)) { - log(1, 0, s, t, "CHAP user too long %d\n", len - 21); + log(1, 0, s, t, "CHAP user too long %d\n", l - 16); STAT(tunnel_rx_errors); return ; } @@ -178,10 +194,14 @@ 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(len-20, 1); - packet.password = calloc(16, 1); - memcpy(packet.username, p + 21, len - 21); - memcpy(packet.password, p + 5, 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) @@ -222,7 +242,7 @@ char *ppp_lcp_types[] = { void dumplcp(u8 *p, int l) { - signed int x = l - 4; + int x = l - 4; u8 *o = (p + 4); log_hex(5, "PPP LCP Packet", p, l); @@ -261,8 +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); @@ -305,12 +325,12 @@ void dumplcp(u8 *p, int l) } // Process LCP messages -void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) +void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l) { u8 b[MAXCONTROL]; u8 *q = NULL; - u32 magicno = 0; - + u32 magicno = 0; + u16 hl; CSTAT(call_processlcp); @@ -321,6 +341,15 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) STAT(tunnel_rx_errors); return ; } + + if ((hl = ntohs(*(u16 *) (p + 2))) > l) + { + log(1, 0, s, t, "Length mismatch LCP %u/%u\n", hl, l); + STAT(tunnel_rx_errors); + return ; + } + l = hl; + if (*p == ConfigAck) { log(3, session[s].ip, s, t, "LCP: Discarding ConfigAck\n"); @@ -328,11 +357,11 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) } else if (*p == ConfigReq) { - signed int x = l - 4; + int x = l - 4; u8 *o = (p + 4); log(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l); - dumplcp(p, l); + if (config->debug > 3) dumplcp(p, l); while (x > 2) { @@ -351,7 +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"); @@ -365,7 +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; @@ -411,8 +440,8 @@ 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); + // for win2k L2TP clients and LCP renegotiation of alive session + if (magicno || l == 4 || (session[s].mru && l == 8)) initlcp(t, s); q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); if (!q) { @@ -435,7 +464,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) else if (*p == ConfigNak) { log(1, session[s].ip, s, t, "Remote end sent a ConfigNak. Ignoring\n"); - dumplcp(p, l); + if (config->debug > 3) dumplcp(p, l); return ; } else if (*p == TerminateReq) @@ -496,8 +525,9 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) } // Process IPCP messages -void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) +void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l) { + u16 hl; CSTAT(call_processipcp); @@ -508,11 +538,21 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) STAT(tunnel_rx_errors); return ; } + + if ((hl = ntohs(*(u16 *) (p + 2))) > l) + { + log(1, 0, s, t, "Length mismatch IPCP %u/%u\n", hl, l); + STAT(tunnel_rx_errors); + return ; + } + l = hl; + if (*p == ConfigAck) { // 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) @@ -530,12 +570,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) 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); - STAT(tunnel_rx_errors); - return ; - } + if (!session[s].ip) { log(3, 0, s, t, "Waiting on radius reply\n"); @@ -547,7 +582,6 @@ 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]) @@ -632,11 +666,10 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) // // This MUST be called with at least 4 byte behind 'p'. // (i.e. this routine writes to p[-4]). -void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l) +void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l) { ipt ip; - CSTAT(call_processipin); log_hex(5, "IP", p, l); @@ -657,6 +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); @@ -674,11 +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, send it to ASIO - snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port); - } STAT(tun_tx_packets); INC_STAT(tun_tx_bytes, l); @@ -722,7 +756,7 @@ void send_ipin(sessionidt s, u8 *buf, int len) // Process LCP messages -void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l) +void processccp(tunnelidt t, sessionidt s, u8 *p, u16 l) { CSTAT(call_processccp); @@ -730,7 +764,7 @@ void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l) log_hex(5, "CCP", p, l); if (l < 2 || (*p != ConfigReq && *p != TerminateReq)) { - log(1, 0, s, t, "Unexpecetd CCP request code %d\n", *p); + log(1, 0, s, t, "Unexpected CCP request code %d\n", *p); STAT(tunnel_rx_errors); return ; } @@ -812,9 +846,8 @@ void sendchap(tunnelidt t, sessionidt s) // fill in a L2TP message with a PPP frame, // copies existing PPP message and changes magic number if seen // returns start of PPP frame -u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype) +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!! @@ -822,7 +855,7 @@ 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 && !(session[s].l2tp_flags & SESSIONACFC)) + if (mtype == PPPLCP || !(session[s].l2tp_flags & SESSIONACFC)) { *(u16 *) b = htons(0xFF03); // HDLC header b += 2; @@ -845,7 +878,7 @@ u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtyp } // find a PPP option, returns point to option, or 0 if not found -u8 *findppp(u8 * b, u8 mtype) +u8 *findppp(u8 *b, u8 mtype) { u16 l = ntohs(*(u16 *) (b + 2)); if (l < 4) @@ -883,7 +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); }