X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/f7a59cd6cca9d4188566c9ca9870edfb24f9b0a0..caeeb2635b57904e554e046815fa16ab5c3749db:/ppp.c diff --git a/ppp.c b/ppp.c index e162f06..9671118 100644 --- a/ppp.c +++ b/ppp.c @@ -1,6 +1,6 @@ // L2TPNS PPP Stuff -char const *cvs_id_ppp = "$Id: ppp.c,v 1.10 2004-08-02 05:40:21 fred_nerk Exp $"; +char const *cvs_id_ppp = "$Id: ppp.c,v 1.19 2004-11-04 23:33:13 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; @@ -76,26 +80,27 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) return; } if (session[s].ip) - *p = 2; // ACK + *p = 2; // ACK else - *p = 3; // cant authorise + *p = 3; // cant authorise p[1] = id; - *(u16 *) (p + 2) = htons(5); // length - p[4] = 0; // no message + *(u16 *) (p + 2) = htons(5); // length + p[4] = 0; // no message if (session[s].ip) { - log(3, session[s].ip, s, t, "%d Already an IP allocated: %s (%d)\n", getpid(), inet_toa(htonl(session[s].ip)), session[s].ip_pool_index); + log(3, session[s].ip, s, t, "%d Already an IP allocated: %s (%d)\n", getpid(), inet_toa(htonl(session[s].ip)), session[s].ip_pool_index); session[s].flags &= ~SF_IPCP_ACKED; } else { - log(1, 0, s, t, "No radius session available to authenticate session...\n"); + log(1, 0, s, t, "No radius session available to authenticate session...\n"); } log(3, 0, s, t, "Fallback response to PAP (%s)\n", (session[s].ip) ? "ACK" : "NAK"); tunnelsend(b, 5 + (p - b), t); // send it } else - { // set up RADIUS request + { + // set up RADIUS request u16 r = session[s].radius; // Run PRE_AUTH plugins @@ -122,11 +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); @@ -141,6 +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); @@ -153,22 +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 ; } @@ -177,10 +194,10 @@ 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.username = calloc(l - 16 + 1, 1); packet.password = calloc(16, 1); - memcpy(packet.username, p + 21, len - 21); - memcpy(packet.password, p + 5, 16); + memcpy(packet.username, p + 16, l - 16); + memcpy(packet.password, p, 16); run_plugins(PLUGIN_PRE_AUTH, &packet); if (!packet.continue_auth) @@ -221,7 +238,7 @@ 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); @@ -250,7 +267,7 @@ void dumplcp(u8 *p, int l) { case 1: // Maximum-Receive-Unit if (length == 4) - log(4, 0, 0, 0, " %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2))); + log(4, 0, 0, 0, " %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2))); else log(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length); break; @@ -258,7 +275,7 @@ void dumplcp(u8 *p, int l) { if (length == 4) { - int proto = ntohs(*(u16 *)(o + 2)); + 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"); @@ -277,8 +294,8 @@ void dumplcp(u8 *p, int l) { if (length == 6) { - u32 magicno = ntohl(*(u32 *)(o + 2)); - log(4, 0, 0, 0, " %s %x\n", lcp_types[type], magicno); + u32 magicno = ntohl(*(u32 *)(o + 2)); + log(4, 0, 0, 0, " %s %x\n", lcp_types[type], magicno); } else log(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length); @@ -304,12 +321,12 @@ 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); @@ -320,6 +337,15 @@ 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"); @@ -327,11 +353,11 @@ 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) { @@ -410,15 +436,16 @@ 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 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) { + if (!q) + { log(3, session[s].ip, s, t, " failed to create packet.\n"); return; } *q = ConfigAck; tunnelsend(b, l + (q - b), t); - // For win2k L2TP clients, LCP should be initiated by the LNS - if (magicno) initlcp(t, s); } else { @@ -433,12 +460,12 @@ 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) { - *p = TerminateAck; // close + *p = TerminateAck; // close q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); if (!q) { log(3, session[s].ip, s, t, "Failed to create PPP packet in processlcp.\n"); @@ -454,7 +481,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) } else if (*p == EchoReq) { - *p = EchoReply; // reply + *p = EchoReply; // reply *(u32 *) (p + 4) = htonl(session[s].magic); // our magic number q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); if (!q) { @@ -494,8 +521,9 @@ 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); @@ -506,11 +534,21 @@ 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) @@ -528,16 +566,11 @@ 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"); - return ; // have to wait on RADIUS reply + return; // have to wait on RADIUS reply } // form a config reply quoting the IP in the session { @@ -545,7 +578,6 @@ 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]) @@ -602,7 +634,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) log(5, session[s].ip, s, t, " DNS2 = %s\n", inet_toa(session[s].dns1)); } } - i = findppp(p, 3); // IP address + i = findppp(p, 3); // IP address if (!i || i[1] != 6) { log(1, 0, s, t, "No IP in IPCP request\n"); @@ -614,7 +646,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) *(u32 *) (i + 2) = htonl(session[s].ip); *p = ConfigNak; log(4, session[s].ip, s, t, " No, a ConfigNak, client is requesting IP - sending %s\n", - inet_toa(session[s].ip)); + inet_toa(htonl(session[s].ip))); } if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP))) { @@ -630,11 +662,10 @@ 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); @@ -655,6 +686,12 @@ 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); @@ -672,11 +709,6 @@ 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); @@ -720,7 +752,7 @@ 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); @@ -728,7 +760,7 @@ 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 ; } @@ -744,12 +776,12 @@ void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l) } else { - *p = ConfigRej; // reject + *p = ConfigRej; // reject sendccp(t, s); } } else - *p = TerminateAck; // close + *p = TerminateAck; // close if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP))) { log(1,0,0,0, "Failed to send CCP packet.\n"); @@ -775,12 +807,13 @@ void sendchap(tunnelidt t, sessionidt s) return ; } log(1, 0, s, t, "Send CHAP challenge\n"); - { // new challenge + { + // new challenge int n; for (n = 0; n < 15; n++) radius[r].auth[n] = rand(); } - radius[r].chap = 1; // CHAP not PAP + radius[r].chap = 1; // CHAP not PAP radius[r].id++; if (radius[r].state != RADIUSCHAP) radius[r].try = 0; @@ -797,11 +830,11 @@ void sendchap(tunnelidt t, sessionidt s) log(1, 0, s, t, "failed to send CHAP challenge.\n"); return; } - *q = 1; // challenhe - q[1] = radius[r].id; // ID - q[4] = 16; // length - memcpy(q + 5, radius[r].auth, 16); // challenge - strcpy(q + 21, hostname); // our name + *q = 1; // challenge + q[1] = radius[r].id; // ID + q[4] = 16; // length + memcpy(q + 5, radius[r].auth, 16); // challenge + strcpy(q + 21, hostname); // our name *(u16 *) (q + 2) = htons(strlen(hostname) + 21); // length tunnelsend(b, strlen(hostname) + 21 + (q - b), t); // send it } @@ -809,9 +842,8 @@ 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!! @@ -819,7 +851,7 @@ 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; @@ -842,7 +874,7 @@ 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) @@ -852,7 +884,7 @@ u8 *findppp(u8 * b, u8 mtype) while (l) { if (l < b[1] || !b[1]) - return 0; // faulty + return 0; // faulty if (*b == mtype) return b; l -= b[1]; @@ -874,11 +906,14 @@ void initlcp(tunnelidt t, sessionidt s) log(4, 0, s, t, "Sending LCP ConfigReq for PAP\n"); *q = ConfigReq; *(u8 *)(q + 1) = (time_now % 255) + 1; // ID - *(u16 *)(q + 2) = htons(8); // Length - *(u8 *)(q + 4) = 3; - *(u8 *)(q + 5) = 4; - *(u16 *)(q + 6) = htons(0xC023); // PAP - tunnelsend(b, 12 + 8, t); + *(u16 *)(q + 2) = htons(14); // Length + *(u8 *)(q + 4) = 5; + *(u8 *)(q + 5) = 6; + *(u32 *)(q + 6) = htonl(session[s].magic); + *(u8 *)(q + 10) = 3; + *(u8 *)(q + 11) = 4; + *(u16 *)(q + 12) = htons(0xC023); // PAP + tunnelsend(b, 12 + 14, t); } // Send CCP reply