X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/ab0c6fbd45590903427775b8bc5a35b5dcc9056f..f5fb6dea8634c6c3d41857225c4b26d4c0f1c960:/ppp.c diff --git a/ppp.c b/ppp.c index ed30501..c69c603 100644 --- a/ppp.c +++ b/ppp.c @@ -1,6 +1,6 @@ // L2TPNS PPP Stuff -char const *cvs_id_ppp = "$Id: ppp.c,v 1.15 2004-09-19 23:19:23 fred_nerk Exp $"; +char const *cvs_id_ppp = "$Id: ppp.c,v 1.38 2004-11-30 19:34:57 bodea Exp $"; #include #include @@ -21,38 +21,42 @@ extern int tunfd; extern char hostname[]; extern u32 eth_tx; extern time_t time_now; -extern struct configt *config; +extern configt *config; -void sendccp(tunnelidt t, sessionidt s); +static void initccp(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); - log_hex(5, "PAP", p, l); + LOG_HEX(5, "PAP", p, l); if (l < 4) { - log(1, 0, s, t, "Short PAP %u bytes\n", l); + LOG(1, s, t, "Short PAP %u bytes\n", 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, 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, s, t, "Unexpected PAP code %d\n", *p); STAT(tunnel_rx_errors); return ; } + { u8 *b = p; b += 4; @@ -63,7 +67,7 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) if (*b && *b < sizeof(pass)) memcpy(pass, b + 1, *b); pass[*b] = 0; - log(3, 0, s, t, "PAP login %s/%s\n", user, pass); + LOG(3, s, t, "PAP login %s/%s\n", user, pass); } if (session[s].ip || !session[s].radius) { @@ -71,10 +75,8 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) u8 b[MAXCONTROL]; u8 id = p[1]; u8 *p = makeppp(b, sizeof(b), 0, 0, t, s, PPPPAP); - if (!p) { // Failed to make ppp header! - log(1,0,0,0, "Failed to make PPP header in process pap!\n"); - return; - } + if (!p) return; + if (session[s].ip) *p = 2; // ACK else @@ -84,14 +86,16 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) 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, s, t, "Already an IP allocated: %s (%d)\n", + fmtaddr(htonl(session[s].ip), 0), 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, 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"); + LOG(3, s, t, "Fallback response to PAP (%s)\n", (session[s].ip) ? "ACK" : "NAK"); tunnelsend(b, 5 + (p - b), t); // send it } else @@ -104,7 +108,7 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) run_plugins(PLUGIN_PRE_AUTH, &packet); if (!packet.continue_auth) { - log(3, 0, s, t, "A plugin rejected PRE_AUTH\n"); + LOG(3, s, t, "A plugin rejected PRE_AUTH\n"); if (packet.username) free(packet.username); if (packet.password) free(packet.password); return; @@ -117,59 +121,71 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) free(packet.password); radius[r].id = p[1]; - log(3, 0, s, t, "Sending login for %s/%s to radius\n", user, pass); + LOG(3, s, t, "Sending login for %s/%s to radius\n", user, pass); radiussend(r, RADIUSAUTH); } } // 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); - log_hex(5, "CHAP", p, l); + LOG_HEX(5, "CHAP", p, l); r = session[s].radius; if (!r) { - log(1, 0, s, t, "Unexpected CHAP message\n"); + LOG(1, s, t, "Unexpected CHAP message\n"); // FIXME: Need to drop the session here. STAT(tunnel_rx_errors); return; } - if (*p != 2) + + if (l < 4) { - log(1, 0, s, t, "Unexpected CHAP response code %d\n", *p); + LOG(1, s, t, "Short CHAP %u bytes\n", l); STAT(tunnel_rx_errors); - return; + return ; } - if (p[1] != radius[r].id) + + if ((hl = ntohs(*(u16 *) (p + 2))) > l) { - log(1, 0, s, t, "Wrong CHAP response ID %d (should be %d) (%d)\n", p[1], radius[r].id, r); + LOG(1, s, t, "Length mismatch CHAP %u/%u\n", hl, l); STAT(tunnel_rx_errors); return ; } - len = ntohs(*(u16 *) (p + 2)); - if (len > l) + l = hl; + + if (*p != 2) + { + LOG(1, s, t, "Unexpected CHAP response code %d\n", *p); + STAT(tunnel_rx_errors); + return; + } + if (p[1] != radius[r].id) { - log(1, 0, s, t, "Bad CHAP length %d\n", len); + LOG(1, s, t, "Wrong CHAP response ID %d (should be %d) (%d)\n", p[1], radius[r].id, r); 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, 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, s, t, "CHAP user too long %d\n", l - 16); STAT(tunnel_rx_errors); return ; } @@ -178,15 +194,19 @@ 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) { - log(3, 0, s, t, "A plugin rejected PRE_AUTH\n"); + LOG(3, s, t, "A plugin rejected PRE_AUTH\n"); if (packet.username) free(packet.username); if (packet.password) free(packet.password); return; @@ -200,11 +220,11 @@ void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l) } radius[r].chap = 1; - log(3, 0, s, t, "CHAP login %s\n", session[s].user); + LOG(3, s, t, "CHAP login %s\n", session[s].user); radiussend(r, RADIUSAUTH); } -char *ppp_lcp_types[] = { +static char *ppp_lcp_types[] = { NULL, "ConfigReq", "ConfigAck", @@ -220,14 +240,14 @@ char *ppp_lcp_types[] = { "IdentRequest", }; -void dumplcp(u8 *p, int l) +static 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); - log(4, 0, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_types[(int)*p], ntohs( ((u16 *) p)[1]) ); - log(4, 0, 0, 0, "Length: %d\n", l); + LOG_HEX(5, "PPP LCP Packet", p, l); + LOG(4, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_types[(int)*p], ntohs( ((u16 *) p)[1]) ); + LOG(4, 0, 0, "Length: %d\n", l); if (*p != ConfigReq && *p != ConfigRej && *p != ConfigAck) return; @@ -237,12 +257,12 @@ void dumplcp(u8 *p, int l) int length = o[1]; if (length < 2) { - log(4, 0, 0, 0, " Option length is %d...\n", length); + LOG(4, 0, 0, " Option length is %d...\n", length); break; } if (type == 0) { - log(4, 0, 0, 0, " Option type is 0...\n"); + LOG(4, 0, 0, " Option type is 0...\n"); x -= length; o += length; continue; @@ -251,52 +271,51 @@ 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, " %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2))); + else + LOG(4, 0, 0, " %s odd length %d\n", lcp_types[type], length); + break; + case 2: // Async-Control-Character-Map + if (length == 6) + { + u32 asyncmap = ntohl(*(u32 *)(o + 2)); + LOG(4, 0, 0, " %s %x\n", lcp_types[type], asyncmap); + } else - log(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length); + LOG(4, 0, 0, " %s odd length %d\n", lcp_types[type], length); break; case 3: // Authentication-Protocol + if (length == 4) { - if (length == 4) - { - 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"); - } - else - log(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length); - break; + int proto = ntohs(*(u16 *)(o + 2)); + LOG(4, 0, 0, " %s 0x%x (%s)\n", lcp_types[type], proto, + proto == PPPCHAP ? "CHAP" : + proto == PPPPAP ? "PAP" : "UNKNOWN"); } + else + LOG(4, 0, 0, " %s odd length %d\n", lcp_types[type], length); + break; case 4: // Quality-Protocol { u32 qp = ntohl(*(u32 *)(o + 2)); - log(4, 0, 0, 0, " %s %x\n", lcp_types[type], qp); - break; + LOG(4, 0, 0, " %s %x\n", lcp_types[type], qp); } + break; case 5: // Magic-Number + if (length == 6) { - if (length == 6) - { - 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); - break; + u32 magicno = ntohl(*(u32 *)(o + 2)); + LOG(4, 0, 0, " %s %x\n", lcp_types[type], magicno); } + else + LOG(4, 0, 0, " %s odd length %d\n", lcp_types[type], length); + break; case 7: // Protocol-Field-Compression - { - log(4, 0, 0, 0, " %s\n", lcp_types[type]); - break; - } case 8: // Address-And-Control-Field-Compression - { - log(4, 0, 0, 0, " %s\n", lcp_types[type]); - break; - } + LOG(4, 0, 0, " %s\n", lcp_types[type]); + break; default: - log(2, 0, 0, 0, " Unknown PPP LCP Option type %d\n", type); + LOG(2, 0, 0, " Unknown PPP LCP Option type %d\n", type); break; } x -= length; @@ -305,150 +324,185 @@ 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); - log_hex(5, "LCP", p, l); + LOG_HEX(5, "LCP", p, l); if (l < 4) { - log(1, session[s].ip, s, t, "Short LCP %d bytes\n", l); + LOG(1, s, t, "Short LCP %d bytes\n", l); + STAT(tunnel_rx_errors); + return ; + } + + if ((hl = ntohs(*(u16 *) (p + 2))) > l) + { + LOG(1, 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"); - session[s].flags |= SESSIONLCPACK; + LOG(3, s, t, "LCP: Discarding ConfigAck\n"); + session[s].flags |= SF_LCP_ACKED; } else if (*p == ConfigReq) { - signed int x = l - 4; + int x = l - 4; u8 *o = (p + 4); + u8 *response = 0; - log(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l); - dumplcp(p, l); + LOG(3, s, t, "LCP: ConfigReq (%d bytes)...\n", l); + if (config->debug > 3) dumplcp(p, l); while (x > 2) { int type = o[0]; int length = o[1]; - if (length == 0 || type == 0) break; + + if (length == 0 || type == 0 || x < length) break; switch (type) { case 1: // Maximum-Receive-Unit session[s].mru = ntohs(*(u16 *)(o + 2)); break; - case 2: // asyncmap - log_hex(2, "PPP LCP Packet", p, l); - log(2, 0, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_types[(int)*p], ntohs( ((u16 *) p)[1]) ); + + case 2: // Async-Control-Character-Map + if (!ntohl(*(u32 *)(o + 2))) // all bits zero is OK + break; + + if (response && *response != ConfigNak) // rej already queued + break; + + LOG(2, s, t, " Remote requesting asyncmap. Rejecting.\n"); + if (!response) + { + q = response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP); + if (!q) break; + *q = ConfigNak; + q += 4; + } + + if ((q - b + 11) > sizeof(b)) + { + LOG(2, s, t, "LCP overflow for asyncmap ConfigNak.\n"); + break; + } + + *q++ = type; + *q++ = 6; + memset(q, 0, 4); // asyncmap 0 + q += 4; + *((u16 *) (response + 2)) = htons(q - response); // LCP header length break; + case 3: // Authentication-Protocol { int proto = ntohs(*(u16 *)(o + 2)); - if (proto == 0xC223) + char proto_name[] = "0x0000"; + if (proto == PPPPAP) + break; + + if (response && *response != ConfigNak) // rej already queued + break; + + if (proto == PPPCHAP) + strcpy(proto_name, "CHAP"); + else + sprintf(proto_name, "%#4.4x", proto); + + LOG(2, s, t, " Remote requesting %s authentication. Rejecting.\n", proto_name); + + if (!response) { - log(2, session[s].ip, s, t, " Remote end is trying to do CHAP. Rejecting it.\n"); - - if (!q) - { - q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); - if (!q) { - log(2, session[s].ip, s, t, " Failed to send packet.\n"); - break; - } - *q++ = ConfigNak; - } - memcpy(q, o, length); - *(u16 *)(q += 2) = htons(0xC023); // NAK -> Use PAP instead - q += length; + q = response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP); + if (!q) break; + *q = ConfigNak; + q += 4; } - break; + + if ((q - b + length) > sizeof(b)) + { + LOG(2, s, t, "LCP overflow for %s ConfigNak.\n", proto_name); + break; + } + + memcpy(q, o, length); + *(u16 *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead + q += length; + *((u16 *) (response + 2)) = htons(q - response); } + break; + case 5: // Magic-Number - { - magicno = ntohl(*(u32 *)(o + 2)); - break; - } + magicno = ntohl(*(u32 *)(o + 2)); + break; + case 4: // Quality-Protocol case 7: // Protocol-Field-Compression case 8: // Address-And-Control-Field-Compression + break; + + default: // Reject any unknown options + LOG(2, s, t, " Rejecting PPP LCP Option type %d\n", type); + if (!response || *response != ConfigRej) // drop nak in favour of rej + { + q = response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP); + if (!q) break; + *q = ConfigRej; + q += 4; + } + + if ((q - b + length) > sizeof(b)) + { + LOG(2, s, t, "LCP overflow for ConfigRej (type=%d).\n", type); break; - case 13: // CallBack option for LCP extention of win2000/routers L2TP client - case 17: - case 18: - { - // Reject LCP CallBack - log(2, session[s].ip, s, t, " PPP LCP Option type %d, len=%d\n", type, length); - memcpy(p + 4, o, length); - *(u16 *)(p + 2) = htons(length + 4); - *p = ConfigRej; - q = makeppp(b,sizeof(b), p, length + 4, t, s, PPPLCP); - tunnelsend(b, 12 + length + 4, t); - return; } - default: - // Reject Unknown LCP Option to stop to send it again - log(2, session[s].ip, s, t, " Unknown PPP LCP Option type %d\n", type); - memcpy(p + 4, o, length); - *(u16 *)(p + 2) = htons(length + 4); - *p = ConfigRej; - q = makeppp(b,sizeof(b), p, length + 4, t, s, PPPLCP); - tunnelsend(b, 12 + length + 4, t); - return; + memcpy(q, o, length); + q += length; + *((u16 *) (response + 2)) = htons(q - response); // LCP header length } x -= length; o += length; } - if (!q) + if (!response) { // 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); - q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); - if (!q) - { - log(3, session[s].ip, s, t, " failed to create packet.\n"); - return; - } + q = response = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); + if (!q) return; *q = ConfigAck; - tunnelsend(b, l + (q - b), t); - } - else - { - // Already built a ConfigNak... send it - log(3, session[s].ip, s, t, "Sending ConfigNak\n"); - tunnelsend(b, l + (q - b), t); } - if (!(session[s].flags & SESSIONLCPACK)) + LOG(3, s, t, "Sending %s\n", ppp_lcp_types[*response]); + tunnelsend(b, l + (q - b), t); + + if (!(session[s].flags & SF_LCP_ACKED)) initlcp(t, s); } else if (*p == ConfigNak) { - log(1, session[s].ip, s, t, "Remote end sent a ConfigNak. Ignoring\n"); - dumplcp(p, l); + LOG(1, s, t, "Remote end sent a ConfigNak. Ignoring\n"); + if (config->debug > 3) dumplcp(p, l); return ; } else if (*p == TerminateReq) { + LOG(3, s, t, "LCP: Received TerminateReq. Sending TerminateAck\n"); *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"); - return; - } - log(3, session[s].ip, s, t, "LCP: Received TerminateReq. Sending TerminateAck\n"); - sessionshutdown(s, "Remote end closed connection."); + if (!q) return; tunnelsend(b, l + (q - b), t); // send it + sessionshutdown(s, "Remote end closed connection."); } else if (*p == TerminateAck) { @@ -456,14 +510,11 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) } else if (*p == EchoReq) { + LOG(5, s, t, "LCP: Received EchoReq. Sending EchoReply\n"); *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) { - log(3, session[s].ip, s, t, " failed to send EchoReply.\n"); - return; - } - log(5, session[s].ip, s, t, "LCP: Received EchoReq. Sending EchoReply\n"); + if (!q) return; tunnelsend(b, l + (q - b), t); // send it } else if (*p == EchoReply) @@ -475,39 +526,65 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) *p = CodeRej; if (l > MAXCONTROL) { - log(1, 0, s, t, "Truncated Ident Packet (length=%d) to 1400 bytes\n", l); + LOG(1, s, t, "Truncated Ident Packet (length=%d) to 1400 bytes\n", l); l = 1400; } q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); - if (!q) - { - log(3, session[s].ip, s, t, "Failed to create IdentRej.\n"); - return; - } - log_hex(5, "LCPIdentRej", q, l + 4); + if (!q) return; + LOG_HEX(5, "LCPIdentRej", q, l + 4); tunnelsend(b, 12 + 4 + l, t); } else { - log(1, session[s].ip, s, t, "Unexpected LCP code %d\n", *p); + LOG(1, s, t, "Unexpected LCP code %d\n", *p); STAT(tunnel_rx_errors); return ; } } +// find a PPP option, returns point to option, or 0 if not found +static u8 *findppp(u8 *b, u8 mtype) +{ + u16 l = ntohs(*(u16 *) (b + 2)); + if (l < 4) + return 0; + b += 4; + l -= 4; + while (l) + { + if (l < b[1] || !b[1]) + return 0; // faulty + if (*b == mtype) + return b; + l -= b[1]; + b += b[1]; + } + return 0; +} + // 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); - log_hex(5, "IPCP", p, l); + LOG_HEX(5, "IPCP", p, l); if (l < 5) { - log(1, 0, s, t, "Short IPCP %d bytes\n", l); + LOG(1, s, t, "Short IPCP %d bytes\n", l); + STAT(tunnel_rx_errors); + return ; + } + + if ((hl = ntohs(*(u16 *) (p + 2))) > l) + { + LOG(1, s, t, "Length mismatch IPCP %u/%u\n", hl, l); STAT(tunnel_rx_errors); return ; } + l = hl; + if (*p == ConfigAck) { // happy with our IPCP @@ -521,25 +598,24 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) } session[s].flags |= SF_IPCP_ACKED; - log(3, session[s].ip, s, t, "IPCP Acked, session is now active\n"); + LOG(3, s, t, "IPCP Acked, session is now active\n"); + + // clear LCP_ACKED/CCP_ACKED flag for possible fast renegotiaion for routers + session[s].flags &= ~(SF_LCP_ACKED|SF_CCP_ACKED); + return; } if (*p != ConfigReq) { - log(1, 0, s, t, "Unexpected IPCP code %d\n", *p); - STAT(tunnel_rx_errors); - 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); + LOG(1, s, t, "Unexpected IPCP code %d\n", *p); STAT(tunnel_rx_errors); return ; } + LOG(4, s, t, "IPCP ConfigReq received\n"); + if (!session[s].ip) { - log(3, 0, s, t, "Waiting on radius reply\n"); + LOG(3, s, t, "Waiting on radius reply\n"); return; // have to wait on RADIUS reply } // form a config reply quoting the IP in the session @@ -548,7 +624,6 @@ 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]) @@ -563,29 +638,27 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) u16 n = 4; i = p + l; if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP))) - { - log(2, 0, s, t, "Failed to send IPCP ConfigRej\n"); return; - } + *q = ConfigRej; p += 4; while (p < i && p[1]) { if (*p != 0x81 && *p != 0x83 && *p != 3) { - log(2, 0, s, t, "IPCP reject %d\n", *p); + LOG(2, s, t, "IPCP reject %d\n", *p); memcpy(q + n, p, p[1]); n += p[1]; } p += p[1]; } *(u16 *) (q + 2) = htons(n); - log(4, session[s].ip, s, t, "Sending ConfigRej\n"); + LOG(4, s, t, "Sending ConfigRej\n"); tunnelsend(b, n + (q - b), t); // send it } else { - log(4, session[s].ip, s, t, "Sending ConfigAck\n"); + LOG(4, s, t, "Sending ConfigAck\n"); *p = ConfigAck; if ((i = findppp(p, 0x81))) // Primary DNS address { @@ -593,7 +666,8 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) { *(u32 *) (i + 2) = htonl(session[s].dns1); *p = ConfigNak; - log(5, session[s].ip, s, t, " DNS1 = %s\n", inet_toa(session[s].dns1)); + LOG(5, s, t, " DNS1 = %s\n", + fmtaddr(htonl(session[s].dns1), 0)); } } if ((i = findppp(p, 0x83))) // Secondary DNS address (TBA, is it) @@ -602,13 +676,14 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) { *(u32 *) (i + 2) = htonl(session[s].dns2); *p = ConfigNak; - log(5, session[s].ip, s, t, " DNS2 = %s\n", inet_toa(session[s].dns1)); + LOG(5, s, t, " DNS2 = %s\n", + fmtaddr(htonl(session[s].dns2), 0)); } } i = findppp(p, 3); // IP address if (!i || i[1] != 6) { - log(1, 0, s, t, "No IP in IPCP request\n"); + LOG(1, s, t, "No IP in IPCP request\n"); STAT(tunnel_rx_errors); return ; } @@ -616,14 +691,12 @@ 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(htonl(session[s].ip))); + LOG(4, s, t, " No, a ConfigNak, client is requesting IP - sending %s\n", + fmtaddr(htonl(session[s].ip), 0)); } if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP))) - { - log(2, 0, s, t, " Failed to send IPCP packet.\n"); return; - } + tunnelsend(b, l + (q - b), t); // send it } } @@ -633,19 +706,19 @@ 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); + LOG_HEX(5, "IP", p, l); ip = ntohl(*(u32 *)(p + 12)); if (l > MAXETHER) { - log(1, ip, s, t, "IP packet too long %d\n", l); + LOG(1, s, t, "IP packet too long %d\n", l); STAT(tunnel_rx_errors); return ; } @@ -653,10 +726,14 @@ void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l) // no spoof (do sessionbyip to handled statically routed subnets) if (ip != session[s].ip && sessionbyip(htonl(ip)) != s) { - log(5, ip, s, t, "Dropping packet with spoofed IP %s\n", inet_toa(htonl(ip))); + LOG(5, s, t, "Dropping packet with spoofed IP %s\n", fmtaddr(htonl(ip), 0)); return; } + // run access-list if any + if (session[s].filter_in && !ip_filter(p, l, session[s].filter_in - 1)) + return; + // Add on the tun header p -= 4; *(u32 *)p = htonl(0x00000800); @@ -667,21 +744,6 @@ void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l) return; } - session[s].cin += l - 4; - session[s].total_cin += l - 4; - sess_count[s].cin += l - 4; - - 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); - if (session[s].tbf_in && config->cluster_iam_master) { // Are we throttled and a master?? actually handle the throttled packets. tbf_queue_packet(session[s].tbf_in, p, l); return; @@ -691,10 +753,27 @@ void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l) if (tun_write(p, l) < 0) { STAT(tun_tx_errors); - log(0, 0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n", + LOG(0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n", l, strerror(errno), tunfd, p); + + return; } + if (session[s].snoop_ip && session[s].snoop_port) + { + // Snooping this session + snoop_send_packet(p + 4, l - 4, session[s].snoop_ip, session[s].snoop_port); + } + + session[s].cin += l - 4; + session[s].total_cin += l - 4; + sess_count[s].cin += l - 4; + + session[s].pin++; + eth_tx += l - 4; + + STAT(tun_tx_packets); + INC_STAT(tun_tx_bytes, l - 4); } // @@ -703,12 +782,21 @@ void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l) // void send_ipin(sessionidt s, u8 *buf, int len) { - log_hex(5, "IP in throttled", buf, len); + LOG_HEX(5, "IP in throttled", buf, len); + if (write(tunfd, buf, len) < 0) { STAT(tun_tx_errors); - log(0, 0, 0, 0, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n", + LOG(0, 0, 0, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n", len, strerror(errno), tunfd, buf); + + return; + } + + if (session[s].snoop_ip && session[s].snoop_port) + { + // Snooping this session + snoop_send_packet(buf + 4, len - 4, session[s].snoop_ip, session[s].snoop_port); } // Increment packet counters @@ -718,47 +806,61 @@ void send_ipin(sessionidt s, u8 *buf, int len) session[s].pin++; eth_tx += len - 4; + + STAT(tun_tx_packets); + INC_STAT(tun_tx_bytes, len - 4); } -// Process LCP messages -void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l) +// Process CCP messages +void processccp(tunnelidt t, sessionidt s, u8 *p, u16 l) { + u8 b[MAXCONTROL]; + u8 *q; CSTAT(call_processccp); - 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); - STAT(tunnel_rx_errors); - return ; - } - // reject + LOG_HEX(5, "CCP", p, l); + switch (l > 1 ? *p : 0) { - u8 b[MAXCONTROL]; - u8 *q; - if (*p == ConfigReq) + case ConfigAck: + session[s].flags |= SF_CCP_ACKED; + return; + + case ConfigReq: + if (l < 6) // accept no compression { - if (l < 6) - { - *p = ConfigAck; // accept no compression - } - else - { - *p = ConfigRej; // reject - sendccp(t, s); - } + *p = ConfigAck; + break; } + + // compression requested--reject + *p = ConfigRej; + + // send CCP request for no compression for our end if not negotiated + if (!(session[s].flags & SF_CCP_ACKED)) + initccp(t, s); + + break; + + case TerminateReq: + *p = TerminateAck; + break; + + default: + if (l > 1) + LOG(1, s, t, "Unexpected CCP request code %d\n", *p); else - *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"); - return; - } - tunnelsend(b, l + (q - b), t); // send it + LOG(1, s, t, "Short CCP packet\n"); + + STAT(tunnel_rx_errors); + return; } + + if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP))) + return; + + tunnelsend(b, l + (q - b), t); // send it } // send a CHAP PP packet @@ -772,11 +874,11 @@ void sendchap(tunnelidt t, sessionidt s) if (!r) { - log(1, 0, s, t, "No RADIUS to send challenge\n"); + LOG(1, s, t, "No RADIUS to send challenge\n"); STAT(tunnel_tx_errors); return ; } - log(1, 0, s, t, "Send CHAP challenge\n"); + LOG(1, s, t, "Send CHAP challenge\n"); { // new challenge int n; @@ -796,10 +898,8 @@ void sendchap(tunnelidt t, sessionidt s) return ; } q = makeppp(b, sizeof(b), 0, 0, t, s, PPPCHAP); - if (!q) { - log(1, 0, s, t, "failed to send CHAP challenge.\n"); - return; - } + if (!q) return; + *q = 1; // challenge q[1] = radius[r].id; // ID q[4] = 16; // length @@ -812,16 +912,21 @@ 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!! + 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; + } *(u16 *) (b + 0) = htons(0x0002); // L2TP with no options *(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; @@ -834,46 +939,29 @@ u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtyp b += 2; } - if (l + 12 > size) { - log(3,0,0,0, "Would have overflowed the buffer in makeppp: size %d, len %d.\n", size, l); - return NULL; // Run out of room to hold the packet! + 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; } + if (p && l) memcpy(b, p, l); - return b; -} -// find a PPP option, returns point to option, or 0 if not found -u8 *findppp(u8 * b, u8 mtype) -{ - u16 l = ntohs(*(u16 *) (b + 2)); - if (l < 4) - return 0; - b += 4; - l -= 4; - while (l) - { - if (l < b[1] || !b[1]) - return 0; // faulty - if (*b == mtype) - return b; - l -= b[1]; - b += b[1]; - } - return 0; + return b; } -// Send initial LCP ConfigReq +// Send initial LCP ConfigReq for PAP, set magic no. void initlcp(tunnelidt t, sessionidt s) { - char b[500] = {0}, *q; + char b[500], *q; - q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP); - if (!q) { - log(1, 0, s, t, "Failed to send LCP ConfigReq.\n"); + if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP))) return; - } - log(4, 0, s, t, "Sending LCP ConfigReq for PAP\n"); + + LOG(4, s, t, "Sending LCP ConfigReq for PAP\n"); *q = ConfigReq; *(u8 *)(q + 1) = (time_now % 255) + 1; // ID *(u16 *)(q + 2) = htons(14); // Length @@ -882,20 +970,25 @@ 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 - tunnelsend(b, 12 + 14, t); + *(u16 *)(q + 12) = htons(PPPPAP); // PAP + + LOG_HEX(5, "PPPLCP", q, 14); + tunnelsend(b, (q - b) + 14, t); } -// Send CCP reply -void sendccp(tunnelidt t, sessionidt s) +// Send CCP request for no compression +static void initccp(tunnelidt t, sessionidt s) { - char *q, b[500] = {0}; + char b[500], *q; - q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP); + if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP))) + return; + + LOG(4, s, t, "Sending CCP ConfigReq for no compression\n"); *q = ConfigReq; *(u8 *)(q + 1) = (time_now % 255) + 1; // ID *(u16 *)(q + 2) = htons(4); // Length - log_hex(5, "PPPCCP", q, 4); + + LOG_HEX(5, "PPPCCP", q, 4); tunnelsend(b, (q - b) + 4 , t); } -