X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/811379c1a6bed85a984578256646e70a9f203b57..3e92edac6a72ab10310f55abf54d7588cd993c4b:/ppp.c?ds=sidebyside diff --git a/ppp.c b/ppp.c index b954e32..92349e4 100644 --- a/ppp.c +++ b/ppp.c @@ -1,6 +1,6 @@ // L2TPNS PPP Stuff -char const *cvs_id_ppp = "$Id: ppp.c,v 1.46 2005/03/10 06:16:05 bodea Exp $"; +char const *cvs_id_ppp = "$Id: ppp.c,v 1.82 2005/09/16 05:04:29 bodea Exp $"; #include #include @@ -23,14 +23,15 @@ extern uint32_t eth_tx; extern time_t time_now; extern configt *config; -static void initccp(tunnelidt t, sessionidt s); +static int add_lcp_auth(uint8_t *b, int size, int authtype); // Process PAP messages -void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) +void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { char user[MAXUSER]; char pass[MAXPASS]; uint16_t hl; + uint16_t r; CSTAT(processpap); @@ -39,14 +40,16 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) { LOG(1, s, t, "Short PAP %u bytes\n", l); STAT(tunnel_rx_errors); - return ; + sessionshutdown(s, "Short PAP packet.", 3, 0); + return; } if ((hl = ntohs(*(uint16_t *) (p + 2))) > l) { LOG(1, s, t, "Length mismatch PAP %u/%u\n", hl, l); STAT(tunnel_rx_errors); - return ; + sessionshutdown(s, "PAP length mismatch.", 3, 0); + return; } l = hl; @@ -54,7 +57,14 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) { LOG(1, s, t, "Unexpected PAP code %d\n", *p); STAT(tunnel_rx_errors); - return ; + sessionshutdown(s, "Unexpected PAP code.", 3, 0); + return; + } + + if (session[s].ppp.phase != Authenticate) + { + LOG(2, s, t, "PAP ignored in %s phase\n", ppp_phase(session[s].ppp.phase)); + return; } { @@ -74,12 +84,13 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) } LOG(3, s, t, "PAP login %s/%s\n", user, pass); } - if (session[s].ip || !session[s].radius) + + if (session[s].ip || !(r = radiusnew(s))) { // respond now, either no RADIUS available or already authenticated - uint8_t b[MAXCONTROL]; + uint8_t b[MAXETHER]; uint8_t id = p[1]; - uint8_t *p = makeppp(b, sizeof(b), 0, 0, t, s, PPPPAP); + uint8_t *p = makeppp(b, sizeof(b), 0, 0, s, t, PPPPAP); if (!p) return; if (session[s].ip) @@ -89,25 +100,21 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) p[1] = id; *(uint16_t *) (p + 2) = htons(5); // length p[4] = 0; // no message + tunnelsend(b, 5 + (p - b), t); // send it + if (session[s].ip) { 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, s, t, "No radius session available to authenticate session...\n"); + LOG(1, s, t, "No RADIUS session available to authenticate session...\n"); + sessionshutdown(s, "No free RADIUS sessions.", 4, 0); } - LOG(3, 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 - uint16_t r = session[s].radius; - // Run PRE_AUTH plugins struct param_pre_auth packet = { &tunnel[t], &session[s], strdup(user), strdup(pass), PPPPAP, 1 }; run_plugins(PLUGIN_PRE_AUTH, &packet); @@ -126,13 +133,13 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) free(packet.password); radius[r].id = p[1]; - LOG(3, 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, uint8_t *p, uint16_t l) +void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { uint16_t r; uint16_t hl; @@ -140,26 +147,21 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) CSTAT(processchap); LOG_HEX(5, "CHAP", p, l); - r = session[s].radius; - if (!r) - { - LOG(1, s, t, "Unexpected CHAP message\n"); - STAT(tunnel_rx_errors); - return; - } if (l < 4) { LOG(1, s, t, "Short CHAP %u bytes\n", l); STAT(tunnel_rx_errors); - return ; + sessionshutdown(s, "Short CHAP packet.", 3, 0); + return; } if ((hl = ntohs(*(uint16_t *) (p + 2))) > l) { LOG(1, s, t, "Length mismatch CHAP %u/%u\n", hl, l); STAT(tunnel_rx_errors); - return ; + sessionshutdown(s, "CHAP length mismatch.", 3, 0); + return; } l = hl; @@ -167,20 +169,37 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) { LOG(1, s, t, "Unexpected CHAP response code %d\n", *p); STAT(tunnel_rx_errors); + sessionshutdown(s, "CHAP length mismatch.", 3, 0); + return; + } + + r = sess_local[s].radius; + if (!r) + { + LOG(3, s, t, "Unexpected CHAP message\n"); + return; + } + + if (session[s].ppp.phase != Authenticate) + { + LOG(2, s, t, "CHAP ignored in %s phase\n", ppp_phase(session[s].ppp.phase)); return; } + if (p[1] != radius[r].id) { 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 ; + sessionshutdown(s, "Unexpected CHAP response ID.", 3, 0); + return; } if (l < 5 || p[4] != 16) { LOG(1, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]); STAT(tunnel_rx_errors); - return ; + sessionshutdown(s, "Bad CHAP response length.", 3, 0); + return; } l -= 5; @@ -189,7 +208,8 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) { LOG(1, s, t, "CHAP user too long %d\n", l - 16); STAT(tunnel_rx_errors); - return ; + sessionshutdown(s, "CHAP username too long.", 3, 0); + return; } // Run PRE_AUTH plugins @@ -232,7 +252,7 @@ static void dumplcp(uint8_t *p, int l) uint8_t *o = (p + 4); LOG_HEX(5, "PPP LCP Packet", p, l); - LOG(4, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_type((int)*p), ntohs( ((uint16_t *) p)[1]) ); + LOG(4, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_code((int)*p), ntohs( ((uint16_t *) p)[1]) ); LOG(4, 0, 0, "Length: %d\n", l); if (*p != ConfigReq && *p != ConfigRej && *p != ConfigAck) return; @@ -257,48 +277,54 @@ static void dumplcp(uint8_t *p, int l) { case 1: // Maximum-Receive-Unit if (length == 4) - LOG(4, 0, 0, " %s %d\n", lcp_type(type), ntohs(*(uint16_t *)(o + 2))); + LOG(4, 0, 0, " %s %d\n", ppp_lcp_option(type), ntohs(*(uint16_t *)(o + 2))); else - LOG(4, 0, 0, " %s odd length %d\n", lcp_type(type), length); + LOG(4, 0, 0, " %s odd length %d\n", ppp_lcp_option(type), length); break; case 2: // Async-Control-Character-Map if (length == 6) { uint32_t asyncmap = ntohl(*(uint32_t *)(o + 2)); - LOG(4, 0, 0, " %s %x\n", lcp_type(type), asyncmap); + LOG(4, 0, 0, " %s %x\n", ppp_lcp_option(type), asyncmap); } else - LOG(4, 0, 0, " %s odd length %d\n", lcp_type(type), length); + LOG(4, 0, 0, " %s odd length %d\n", ppp_lcp_option(type), length); break; case 3: // Authentication-Protocol if (length == 4) { int proto = ntohs(*(uint16_t *)(o + 2)); - LOG(4, 0, 0, " %s 0x%x (%s)\n", lcp_type(type), proto, - proto == PPPCHAP ? "CHAP" : - proto == PPPPAP ? "PAP" : "UNKNOWN"); + LOG(4, 0, 0, " %s 0x%x (%s)\n", ppp_lcp_option(type), proto, + proto == PPPPAP ? "PAP" : "UNSUPPORTED"); + } + else if (length == 5) + { + int proto = ntohs(*(uint16_t *)(o + 2)); + int algo = *(o + 4); + LOG(4, 0, 0, " %s 0x%x 0x%x (%s)\n", ppp_lcp_option(type), proto, algo, + (proto == PPPCHAP && algo == 5) ? "CHAP MD5" : "UNSUPPORTED"); } else - LOG(4, 0, 0, " %s odd length %d\n", lcp_type(type), length); + LOG(4, 0, 0, " %s odd length %d\n", ppp_lcp_option(type), length); break; case 4: // Quality-Protocol { uint32_t qp = ntohl(*(uint32_t *)(o + 2)); - LOG(4, 0, 0, " %s %x\n", lcp_type(type), qp); + LOG(4, 0, 0, " %s %x\n", ppp_lcp_option(type), qp); } break; case 5: // Magic-Number if (length == 6) { uint32_t magicno = ntohl(*(uint32_t *)(o + 2)); - LOG(4, 0, 0, " %s %x\n", lcp_type(type), magicno); + LOG(4, 0, 0, " %s %x\n", ppp_lcp_option(type), magicno); } else - LOG(4, 0, 0, " %s odd length %d\n", lcp_type(type), length); + LOG(4, 0, 0, " %s odd length %d\n", ppp_lcp_option(type), length); break; case 7: // Protocol-Field-Compression case 8: // Address-And-Control-Field-Compression - LOG(4, 0, 0, " %s\n", lcp_type(type)); + LOG(4, 0, 0, " %s\n", ppp_lcp_option(type)); break; default: LOG(2, 0, 0, " Unknown PPP LCP Option type %d\n", type); @@ -309,10 +335,144 @@ static void dumplcp(uint8_t *p, int l) } } +void lcp_open(sessionidt s, tunnelidt t) +{ + // transition to Authentication or Network phase: + session[s].ppp.phase = sess_local[s].lcp_authtype ? Authenticate : Network; + + LOG(3, s, t, "LCP: Opened, phase %s\n", ppp_phase(session[s].ppp.phase)); + + // LCP now Opened + change_state(s, lcp, Opened); + + if (session[s].ppp.phase == Authenticate) + { + if (sess_local[s].lcp_authtype == AUTHCHAP) + sendchap(s, t); + } + else + { + // This-Layer-Up + sendipcp(s, t); + change_state(s, ipcp, RequestSent); + // move to passive state for IPv6 (if configured), CCP + if (config->ipv6_prefix.s6_addr[0]) + change_state(s, ipv6cp, Stopped); + else + change_state(s, ipv6cp, Closed); + + change_state(s, ccp, Stopped); + } +} + +static void lcp_restart(sessionidt s) +{ + session[s].ppp.phase = Establish; + // This-Layer-Down + change_state(s, ipcp, Dead); + change_state(s, ipv6cp, Dead); + change_state(s, ccp, Dead); +} + +static uint8_t *ppp_conf_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype, + uint8_t **response, uint8_t *queued, uint8_t *packet, uint8_t *option) +{ + if (!*response || **response != ConfigRej) + { + queued = *response = makeppp(buf, blen, packet, 2, s, session[s].tunnel, mtype); + if (!queued) + return 0; + + *queued = ConfigRej; + queued += 4; + } + + if ((queued - buf + option[1]) > blen) + { + LOG(2, s, session[s].tunnel, "PPP overflow for ConfigRej (proto %u, option %u).\n", mtype, *option); + return 0; + } + + memcpy(queued, option, option[1]); + return queued + option[1]; +} + +static uint8_t *ppp_conf_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype, + uint8_t **response, uint8_t *queued, uint8_t *packet, uint8_t *option, + uint8_t *value, size_t vlen) +{ + int *nak_sent; + switch (mtype) + { + case PPPLCP: nak_sent = &sess_local[s].lcp.nak_sent; break; + case PPPIPCP: nak_sent = &sess_local[s].ipcp.nak_sent; break; + case PPPIPV6CP: nak_sent = &sess_local[s].ipv6cp.nak_sent; break; + default: return 0; // ? + } + + if (*response && **response != ConfigNak) + { + if (*nak_sent < config->ppp_max_failure) // reject queued + return queued; + + return ppp_conf_rej(s, buf, blen, mtype, response, 0, packet, option); + } + + if (!*response) + { + if (*nak_sent >= config->ppp_max_failure) + return ppp_conf_rej(s, buf, blen, mtype, response, 0, packet, option); + + queued = *response = makeppp(buf, blen, packet, 2, s, session[s].tunnel, mtype); + if (!queued) + return 0; + + (*nak_sent)++; + *queued = ConfigNak; + queued += 4; + } + + if ((queued - buf + vlen + 2) > blen) + { + LOG(2, s, session[s].tunnel, "PPP overflow for ConfigNak (proto %u, option %u).\n", mtype, *option); + return 0; + } + + *queued++ = *option; + *queued++ = vlen + 2; + memcpy(queued, value, vlen); + return queued + vlen; +} + +static void ppp_code_rej(sessionidt s, tunnelidt t, uint16_t proto, + char *pname, uint8_t *p, uint16_t l, uint8_t *buf, size_t size) +{ + uint8_t *q; + int mru = session[s].mru; + if (mru > size) mru = size; + + l += 4; + if (l > mru) l = mru; + + q = makeppp(buf, size, 0, 0, s, t, proto); + if (!q) return; + + *q = CodeRej; + *(q + 1) = ++sess_local[s].lcp_ident; + *(uint16_t *)(q + 2) = l; + memcpy(q + 4, p, l - 4); + + LOG(2, s, t, "Unexpected %s code %s\n", pname, ppp_code(*p)); + LOG(3, s, t, "%s: send %s\n", pname, ppp_code(*q)); + if (config->debug > 3) dumplcp(q, l); + + tunnelsend(buf, l + (q - buf), t); +} + // Process LCP messages -void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) +void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { - uint8_t b[MAXCONTROL]; + uint8_t b[MAXETHER]; uint8_t *q = NULL; uint32_t magicno = 0; uint16_t hl; @@ -335,19 +495,76 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) } l = hl; + if (session[s].die) // going down... + return; + + LOG(*p == EchoReq ? 4 : 3, s, t, "LCP: recv %s\n", ppp_code(*p)); + if (config->debug > 3) dumplcp(p, l); + if (*p == ConfigAck) { - LOG(3, s, t, "LCP: Discarding ConfigAck\n"); - session[s].flags |= SF_LCP_ACKED; + int x = l - 4; + uint8_t *o = (p + 4); + int authtype = 0; + + while (x > 2) + { + int type = o[0]; + int length = o[1]; + + if (length == 0 || type == 0 || x < length) break; + switch (type) + { + case 3: // Authentication-Protocol + { + int proto = ntohs(*(uint16_t *)(o + 2)); + if (proto == PPPPAP) + authtype = AUTHPAP; + else if (proto == PPPCHAP && *(o + 4) == 5) + authtype = AUTHCHAP; + } + + break; + } + x -= length; + o += length; + } + + if (!session[s].ip && authtype) + sess_local[s].lcp_authtype = authtype; + + switch (session[s].ppp.lcp) + { + case RequestSent: + initialise_restart_count(s, lcp); + change_state(s, lcp, AckReceived); + break; + + case AckReceived: + case Opened: + LOG(2, s, t, "LCP: ConfigAck in state %s? Sending ConfigReq\n", ppp_state(session[s].ppp.lcp)); + if (session[s].ppp.lcp == Opened) + lcp_restart(s); + + sendlcp(s, t); + change_state(s, lcp, RequestSent); + break; + + case AckSent: + lcp_open(s, t); + break; + + default: + LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp)); + } } else if (*p == ConfigReq) { int x = l - 4; uint8_t *o = (p + 4); uint8_t *response = 0; - - LOG(3, s, t, "LCP: ConfigReq (%d bytes)...\n", l); - if (config->debug > 3) dumplcp(p, l); + static uint8_t asyncmap[4] = { 0, 0, 0, 0 }; // all zero + static uint8_t authproto[5]; while (x > 2) { @@ -365,66 +582,56 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) if (!ntohl(*(uint32_t *)(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; - *((uint16_t *) (response + 2)) = htons(q - response); // LCP header length + LOG(3, s, t, " Remote requesting asyncmap. Rejecting.\n"); + q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, asyncmap, sizeof(asyncmap)); break; case 3: // Authentication-Protocol { int proto = ntohs(*(uint16_t *)(o + 2)); char proto_name[] = "0x0000"; + int alen; + if (proto == PPPPAP) - break; + { + if (config->radius_authtypes & AUTHPAP) + { + sess_local[s].lcp_authtype = AUTHPAP; + break; + } - if (response && *response != ConfigNak) // rej already queued - break; + strcpy(proto_name, "PAP"); + } + else if (proto == PPPCHAP) + { + if (config->radius_authtypes & AUTHCHAP + && *(o + 4) == 5) // MD5 + { + sess_local[s].lcp_authtype = AUTHCHAP; + 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); + LOG(3, s, t, " Remote requesting %s authentication. Rejecting.\n", proto_name); - if (!response) - { - q = response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP); - if (!q) break; - *q = ConfigNak; - q += 4; - } + alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authprefer); + if (alen < 2) break; // paranoia - if ((q - b + length) > sizeof(b)) + q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2); + if (q && *response == ConfigNak && + config->radius_authtypes != config->radius_authprefer) { - LOG(2, s, t, "LCP overflow for %s ConfigNak.\n", proto_name); - break; + // alternate type + alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authtypes & ~config->radius_authprefer); + if (alen < 2) break; + q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2); } - memcpy(q, o, length); - *(uint16_t *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead - q += length; - *((uint16_t *) (response + 2)) = htons(q - response); + break; } break; @@ -438,55 +645,205 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) 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 + LOG(3, s, t, " Rejecting unknown PPP LCP option %d\n", type); + q = ppp_conf_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o); + } + x -= length; + o += length; + } + + if (response) + { + l = q - response; // LCP packet length + *((uint16_t *) (response + 2)) = htons(l); // update header + } + else + { + // Send packet back as ConfigAck + response = makeppp(b, sizeof(b), p, l, s, t, PPPLCP); + if (!response) return; + *response = ConfigAck; + } + + switch (session[s].ppp.lcp) + { + case Closed: + response = makeppp(b, sizeof(b), p, 2, s, t, PPPLCP); + if (!response) return; + *response = TerminateAck; + *((uint16_t *) (response + 2)) = htons(l = 4); + break; + + case Stopped: + initialise_restart_count(s, lcp); + sendlcp(s, t); + if (*response == ConfigAck) + change_state(s, lcp, AckSent); + else + change_state(s, lcp, RequestSent); + + break; + + case RequestSent: + if (*response == ConfigAck) + change_state(s, lcp, AckSent); + + break; + + case AckReceived: + if (*response == ConfigAck) + lcp_open(s, t); + + break; + + case Opened: + lcp_restart(s); + sendlcp(s, t); + /* fallthrough */ + + case AckSent: + if (*response == ConfigAck) + change_state(s, lcp, AckSent); + else + change_state(s, lcp, RequestSent); + + break; + + default: + LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp)); + return; + } + + LOG(3, s, t, "LCP: send %s\n", ppp_code(*response)); + if (config->debug > 3) dumplcp(response, l); + + tunnelsend(b, l + (response - b), t); + } + else if (*p == ConfigNak || *p == ConfigRej) + { + int x = l - 4; + uint8_t *o = (p + 4); + int authtype = -1; + + while (x > 2) + { + int type = o[0]; + int length = o[1]; + + if (length == 0 || type == 0 || x < length) break; + switch (type) + { + case 1: // Maximum-Receive-Unit + if (*p == ConfigNak) { - q = response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP); - if (!q) break; - *q = ConfigRej; - q += 4; + sess_local[s].ppp_mru = ntohs(*(uint16_t *)(o + 2)); + LOG(3, s, t, " Remote requested MRU of %u\n", sess_local[s].ppp_mru); } - - if ((q - b + length) > sizeof(b)) + else { - LOG(2, s, t, "LCP overflow for ConfigRej (type=%d).\n", type); + sess_local[s].ppp_mru = 0; + LOG(3, s, t, " Remote rejected MRU negotiation\n"); + } + + break; + + case 3: // Authentication-Protocol + if (authtype > 0) break; + + if (*p == ConfigNak) + { + int proto = ntohs(*(uint16_t *)(o + 2)); + if (proto == PPPPAP) + { + authtype = config->radius_authtypes & AUTHPAP; + LOG(3, s, t, " Remote requested PAP authentication...%sing\n", + authtype ? "accept" : "reject"); + } + else if (proto == PPPCHAP && *(o + 4) == 5) + { + authtype = config->radius_authtypes & AUTHCHAP; + LOG(3, s, t, " Remote requested CHAP authentication...%sing\n", + authtype ? "accept" : "reject"); + } + else + { + LOG(3, s, t, " Rejecting unsupported authentication %#4x\n", + proto); + } } + else + { + LOG(2, s, t, "LCP: remote rejected auth negotiation\n"); + authtype = 0; // shutdown + } + + break; - memcpy(q, o, length); - q += length; - *((uint16_t *) (response + 2)) = htons(q - response); // LCP header length + default: + LOG(2, s, t, "LCP: remote sent %s for type %u?\n", ppp_code(*p), type); + break; } x -= length; o += length; } - if (!response) + if (!authtype) { - // Send back a ConfigAck - q = response = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); - if (!q) return; - *q = ConfigAck; + sessionshutdown(s, "Unsupported authentication.", 3, 0); + return; } - LOG(3, s, t, "Sending %s\n", ppp_lcp_type(*response)); - tunnelsend(b, l + (q - b), t); + if (authtype > 0) + sess_local[s].lcp_authtype = authtype; - if (!(session[s].flags & SF_LCP_ACKED)) - initlcp(t, s); - } - else if (*p == ConfigNak) - { - LOG(1, s, t, "Remote end sent a ConfigNak. Ignoring\n"); - if (config->debug > 3) dumplcp(p, l); - return ; + switch (session[s].ppp.lcp) + { + case Closed: + case Stopped: + { + uint8_t *response = makeppp(b, sizeof(b), p, 2, s, t, PPPLCP); + if (!response) return; + *response = TerminateAck; + *((uint16_t *) (response + 2)) = htons(l = 4); + + LOG(3, s, t, "LCP: send %s\n", ppp_code(*response)); + if (config->debug > 3) dumplcp(response, l); + + tunnelsend(b, l + (response - b), t); + } + break; + + case RequestSent: + case AckSent: + initialise_restart_count(s, lcp); + sendlcp(s, t); + break; + + case AckReceived: + LOG(2, s, t, "LCP: ConfigNak in state %s? Sending ConfigReq\n", ppp_state(session[s].ppp.lcp)); + sendlcp(s, t); + break; + + case Opened: + lcp_restart(s); + sendlcp(s, t); + break; + + default: + LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp)); + 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); + q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP); if (!q) return; + + LOG(3, s, t, "LCP: send %s\n", ppp_code(*q)); + if (config->debug > 3) dumplcp(q, l); + tunnelsend(b, l + (q - b), t); // send it sessionshutdown(s, "Remote end closed connection.", 3, 0); } @@ -496,75 +853,76 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) } else if (*p == ProtocolRej) { - if (*(uint16_t *) (p+4) == htons(PPPIPV6CP)) + uint16_t proto = 0; + + if (l > 4) + { + proto = *(p+4); + if (l > 5 && !(proto & 1)) + { + proto <<= 8; + proto |= *(p+5); + } + } + + if (proto == PPPIPV6CP) { LOG(3, s, t, "IPv6 rejected\n"); - session[s].flags |= SF_IPV6_NACKED; + change_state(s, ipv6cp, Closed); } else { - LOG(1, s, t, "Unexpected LCP protocol reject 0x%X\n", - ntohs(*(uint16_t *) (p+4))); - STAT(tunnel_rx_errors); + LOG(3, s, t, "LCP protocol reject: 0x%04X\n", proto); } } else if (*p == EchoReq) { - LOG(5, s, t, "LCP: Received EchoReq. Sending EchoReply\n"); *p = EchoReply; // reply *(uint32_t *) (p + 4) = htonl(session[s].magic); // our magic number - q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); + q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP); if (!q) return; + + LOG(4, s, t, "LCP: send %s\n", ppp_code(*q)); + if (config->debug > 3) dumplcp(q, l); + tunnelsend(b, l + (q - b), t); // send it } else if (*p == EchoReply) { // Ignore it, last_packet time is set earlier than this. } - else if (*p == IdentRequest) + else if (*p != CodeRej) { - *p = CodeRej; - if (l > MAXCONTROL) - { - 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) return; - LOG_HEX(5, "LCPIdentRej", q, l + 4); - tunnelsend(b, 12 + 4 + l, t); - } - else - { - LOG(1, s, t, "Unexpected LCP code %d\n", *p); - STAT(tunnel_rx_errors); - return ; + ppp_code_rej(s, t, PPPLCP, "LCP", p, l, b, sizeof(b)); } } -// find a PPP option, returns point to option, or 0 if not found -static uint8_t *findppp(uint8_t *b, uint8_t mtype) +static void ipcp_open(sessionidt s, tunnelidt t) { - uint16_t l = ntohs(*(uint16_t *) (b + 2)); - if (l < 4) - return 0; - b += 4; - l -= 4; - while (l) + LOG(3, s, t, "IPCP: Opened, session is now active\n"); + + change_state(s, ipcp, Opened); + + if (!session[s].walled_garden) + { + uint16_t r = radiusnew(s); + if (r) + radiussend(r, RADIUSSTART); // send radius start + } + + // start IPv6 if configured and still in passive state + if (session[s].ppp.ipv6cp == Stopped) { - if (l < b[1] || !b[1]) - return 0; // faulty - if (*b == mtype) - return b; - l -= b[1]; - b += b[1]; + sendipv6cp(s, t); + change_state(s, ipv6cp, RequestSent); } - return 0; } // Process IPCP messages -void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) +void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { + uint8_t b[MAXETHER]; + uint8_t *q = 0; uint16_t hl; CSTAT(processipcp); @@ -585,125 +943,206 @@ void processipcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) } l = hl; + if (session[s].ppp.phase < Network) + { + LOG(2, s, t, "IPCP %s ignored in %s phase\n", ppp_code(*p), ppp_phase(session[s].ppp.phase)); + return; + } + + LOG(3, s, t, "IPCP: recv %s\n", ppp_code(*p)); + if (*p == ConfigAck) { - // happy with our IPCP - uint16_t r = session[s].radius; - if ((!r || radius[r].state == RADIUSIPCP) && !session[s].walled_garden) + switch (session[s].ppp.ipcp) { - if (!r) - r = radiusnew(s); - if (r) - radiussend(r, RADIUSSTART); // send radius start, having got IPCP at last - } - session[s].flags |= SF_IPCP_ACKED; - - LOG(3, s, t, "IPCP Acked, session is now active\n"); + case RequestSent: + initialise_restart_count(s, ipcp); + change_state(s, ipcp, AckReceived); + break; - // clear LCP_ACKED/CCP_ACKED flag for possible fast renegotiaion for routers - session[s].flags &= ~(SF_LCP_ACKED|SF_CCP_ACKED); + case AckReceived: + case Opened: + LOG(2, s, t, "IPCP: ConfigAck in state %s? Sending ConfigReq\n", ppp_state(session[s].ppp.ipcp)); + sendipcp(s, t); + change_state(s, ipcp, RequestSent); + break; - return; - } - if (*p != ConfigReq) - { - LOG(1, s, t, "Unexpected IPCP code %d\n", *p); - STAT(tunnel_rx_errors); - return ; - } - LOG(4, s, t, "IPCP ConfigReq received\n"); + case AckSent: + ipcp_open(s, t); + break; - if (!session[s].ip) - { - LOG(3, s, t, "Waiting on radius reply\n"); - return; // have to wait on RADIUS reply + default: + LOG(2, s, t, "IPCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipcp)); + } } - // form a config reply quoting the IP in the session + else if (*p == ConfigReq) { - uint8_t b[MAXCONTROL]; - uint8_t *i, *q; + uint8_t *response = 0; + uint8_t *o = p + 4; + int length = l - 4; + int gotip = 0; + in_addr_t addr; - q = p + 4; - i = p + l; - while (q < i && q[1]) + while (length > 2) { - if (*q != 0x81 && *q != 0x83 && *q != 3) - break; - q += q[1]; - } - if (q < i) - { - // reject - uint16_t n = 4; - i = p + l; - if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP))) - return; - - *q = ConfigRej; - p += 4; - while (p < i && p[1]) + switch (*o) { - if (*p != 0x81 && *p != 0x83 && *p != 3) + case 3: // ip address + gotip++; // seen address + if (o[1] != 6 || o[1] > length) return; + + addr = htonl(session[s].ip); + if (memcmp(o + 2, &addr, (sizeof addr))) { - LOG(2, s, t, "IPCP reject %d\n", *p); - memcpy(q + n, p, p[1]); - n += p[1]; + uint8_t *oq = q; + q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr)); + if (!q || (q != oq && *response == ConfigRej)) + { + sessionshutdown(s, "Can't negotiate IPCP.", 3, 0); + return; + } } - p += p[1]; - } - *(uint16_t *) (q + 2) = htons(n); - LOG(4, s, t, "Sending ConfigRej\n"); - tunnelsend(b, n + (q - b), t); // send it - } - else - { - LOG(4, s, t, "Sending ConfigAck\n"); - *p = ConfigAck; - if ((i = findppp(p, 0x81))) // Primary DNS address - { - if (*(uint32_t *) (i + 2) != htonl(session[s].dns1)) + + break; + + case 129: // primary DNS + if (o[1] != 6 || o[1] > length) return; + + addr = htonl(session[s].dns1); + if (memcmp(o + 2, &addr, (sizeof addr))) { - *(uint32_t *) (i + 2) = htonl(session[s].dns1); - *p = ConfigNak; - LOG(5, s, t, " DNS1 = %s\n", - fmtaddr(htonl(session[s].dns1), 0)); + q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr)); + if (!q) return; } - } - if ((i = findppp(p, 0x83))) // Secondary DNS address (TBA, is it) - { - if (*(uint32_t *) (i + 2) != htonl(session[s].dns2)) + + break; + + case 131: // secondary DNS + if (o[1] != 6 || o[1] > length) return; + + addr = htonl(session[s].dns1); + if (memcmp(o + 2, &addr, sizeof(addr))) { - *(uint32_t *) (i + 2) = htonl(session[s].dns2); - *p = ConfigNak; - LOG(5, s, t, " DNS2 = %s\n", - fmtaddr(htonl(session[s].dns2), 0)); + q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr)); + if (!q) return; } + + break; + + default: + LOG(2, s, t, " Rejecting PPP IPCP Option type %d\n", *o); + q = ppp_conf_rej(s, b, sizeof(b), PPPIPCP, &response, q, p, o); + if (!q) return; } - i = findppp(p, 3); // IP address - if (!i || i[1] != 6) - { - LOG(1, s, t, "No IP in IPCP request\n"); - STAT(tunnel_rx_errors); - return ; - } - if (*(uint32_t *) (i + 2) != htonl(session[s].ip)) - { - *(uint32_t *) (i + 2) = htonl(session[s].ip); - *p = ConfigNak; - 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))) - return; - tunnelsend(b, l + (q - b), t); // send it + length -= o[1]; + o += o[1]; + } + + if (response) + { + l = q - response; // IPCP packet length + *((uint16_t *) (response + 2)) = htons(l); // update header + } + else if (gotip) + { + // Send packet back as ConfigAck + response = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP); + if (!response) return; + *response = ConfigAck; + } + else + { + LOG(1, s, t, "No IP in IPCP request\n"); + STAT(tunnel_rx_errors); + return; + } + + switch (session[s].ppp.ipcp) + { + case Closed: + response = makeppp(b, sizeof(b), p, 2, s, t, PPPIPCP); + if (!response) return; + *response = TerminateAck; + *((uint16_t *) (response + 2)) = htons(l = 4); + break; + + case Stopped: + initialise_restart_count(s, ipcp); + sendipcp(s, t); + if (*response == ConfigAck) + change_state(s, ipcp, AckSent); + else + change_state(s, ipcp, RequestSent); + + break; + + case RequestSent: + if (*response == ConfigAck) + change_state(s, ipcp, AckSent); + + break; + + case AckReceived: + if (*response == ConfigAck) + ipcp_open(s, t); + + break; + + case Opened: + initialise_restart_count(s, ipcp); + sendipcp(s, t); + /* fallthrough */ + + case AckSent: + if (*response == ConfigAck) + change_state(s, ipcp, AckSent); + else + change_state(s, ipcp, RequestSent); + + break; + + default: + LOG(2, s, t, "IPCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipcp)); + return; } + + LOG(3, s, t, "IPCP: send %s\n", ppp_code(*response)); + tunnelsend(b, l + (response - b), t); } + else if (*p == TerminateReq) + { + *p = TerminateAck; + q = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP); + if (!q) return; + LOG(3, s, t, "IPCP: send %s\n", ppp_code(*q)); + tunnelsend(b, l + (q - b), t); + change_state(s, ipcp, Stopped); + } + else if (*p != CodeRej) + { + ppp_code_rej(s, t, PPPIPCP, "IPCP", p, l, b, sizeof(b)); + } +} + +static void ipv6cp_open(sessionidt s, tunnelidt t) +{ + LOG(3, s, t, "IPV6CP: Opened\n"); + + change_state(s, ipv6cp, Opened); + if (session[s].ipv6prefixlen) + route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 1); + + // Send an initial RA (TODO: Should we send these regularly?) + send_ipv6_ra(s, t, NULL); } // Process IPV6CP messages -void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) +void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { + uint8_t b[MAXETHER]; + uint8_t *q = 0; + uint16_t hl; CSTAT(processipv6cp); @@ -714,112 +1153,173 @@ void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) STAT(tunnel_rx_errors); return ; } - if (*p == ConfigAck) - { - // happy with our IPV6CP - session[s].flags |= SF_IPV6CP_ACKED; - - LOG(3, s, t, "IPV6CP Acked, IPv6 is now active\n"); - // Add a routed block if configured. - if (session[s].ipv6prefixlen) - { - route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 1); - session[s].flags |= SF_IPV6_ROUTED; - } - // Send an initial RA (TODO: Should we send these regularly?) - send_ipv6_ra(t, s, NULL); - return; - } - if (*p != ConfigReq) + if ((hl = ntohs(*(uint16_t *) (p + 2))) > l) { - LOG(1, s, t, "Unexpected IPV6CP code %d\n", *p); + LOG(1, s, t, "Length mismatch IPV6CP %u/%u\n", hl, l); STAT(tunnel_rx_errors); - return; + return ; } + l = hl; - LOG(4, s, t, "IPV6CP ConfigReq received\n"); - if (ntohs(*(uint16_t *) (p + 2)) > l) + if (session[s].ppp.phase < Network) { - LOG(1, s, t, "Length mismatch IPV6CP %d/%d\n", ntohs(*(uint16_t *) (p + 2)), l); - STAT(tunnel_rx_errors); - return ; + LOG(2, s, t, "IPV6CP %s ignored in %s phase\n", ppp_code(*p), ppp_phase(session[s].ppp.phase)); + return; } + + LOG(3, s, t, "IPV6CP: recv %s\n", ppp_code(*p)); + if (!session[s].ip) { - LOG(3, s, t, "Waiting on radius reply\n"); - return; // have to wait on RADIUS reply + LOG(3, s, t, "IPV6CP: no IPv4 address (IPCP in state %s)\n", ppp_state(session[s].ppp.ipcp)); + return; // need IPCP to complete... } - // form a config reply quoting the IP in the session - { - uint8_t b[MAXCONTROL]; - uint8_t *i, - *q; - l = ntohs(*(uint16_t *) (p + 2)); // We must use length from IPV6CP len field - q = p + 4; - i = p + l; - while (q < i && q[1]) + if (*p == ConfigAck) + { + switch (session[s].ppp.ipv6cp) { - if (*q != 1) - break; - q += q[1]; + case RequestSent: + initialise_restart_count(s, ipv6cp); + change_state(s, ipv6cp, AckReceived); + break; + + case AckReceived: + case Opened: + LOG(2, s, t, "IPV6CP: ConfigAck in state %s? Sending ConfigReq\n", ppp_state(session[s].ppp.ipv6cp)); + sendipv6cp(s, t); + change_state(s, ipv6cp, RequestSent); + break; + + case AckSent: + ipv6cp_open(s, t); + break; + + default: + LOG(2, s, t, "IPV6CP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipv6cp)); } - if (q < i) + } + else if (*p == ConfigReq) + { + uint8_t *response = 0; + uint8_t *o = p + 4; + int length = l - 4; + int gotip = 0; + uint8_t ident[8]; + + while (length > 2) { - // reject - uint16_t n = 4; - i = p + l; - if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPV6CP))) + switch (*o) { - LOG(2, s, t, "Failed to send IPV6CP ConfigRej\n"); - return; - } - *q = ConfigRej; - p += 4; - while (p < i && p[1]) - { - if (*p != 1) + case 1: // interface identifier + gotip++; // seen address + if (o[1] != 10 || o[1] > length) return; + + *(uint32_t *) ident = htonl(session[s].ip); + *(uint32_t *) (ident + 4) = 0; + + if (memcmp(o + 2, ident, sizeof(ident))) { - LOG(2, s, t, "IPV6CP reject %d\n", *p); - memcpy(q + n, p, p[1]); - n += p[1]; + q = ppp_conf_nak(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o, ident, sizeof(ident)); + if (!q) return; } - p += p[1]; + + break; + + default: + LOG(2, s, t, " Rejecting PPP IPV6CP Option type %d\n", *o); + q = ppp_conf_rej(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o); + if (!q) return; } - *(uint16_t *) (q + 2) = htons(n); - LOG(4, s, t, "Sending ConfigRej\n"); - tunnelsend(b, n + (q - b), t); // send it + + length -= o[1]; + o += o[1]; + } + + if (response) + { + l = q - response; // IPV6CP packet length + *((uint16_t *) (response + 2)) = htons(l); // update header + } + else if (gotip) + { + // Send packet back as ConfigAck + response = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP); + if (!response) return; + *response = ConfigAck; } else { - LOG(4, s, t, "Sending ConfigAck\n"); - *p = ConfigAck; - i = findppp(p, 1); // IP address - if (!i || i[1] != 10) - { - LOG(1, s, t, "No IP in IPV6CP request\n"); - STAT(tunnel_rx_errors); - return ; - } - if ((*(uint32_t *) (i + 2) != htonl(session[s].ip)) || - (*(uint32_t *) (i + 6) != 0)) - { - *(uint32_t *) (i + 2) = htonl(session[s].ip); - *(uint32_t *) (i + 6) = 0; - *p = ConfigNak; - 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, PPPIPV6CP))) - { - LOG(2, s, t, " Failed to send IPV6CP packet.\n"); - return; - } - tunnelsend(b, l + (q - b), t); // send it + LOG(1, s, t, "No interface identifier in IPV6CP request\n"); + STAT(tunnel_rx_errors); + return; + } + + switch (session[s].ppp.ipv6cp) + { + case Closed: + response = makeppp(b, sizeof(b), p, 2, s, t, PPPIPV6CP); + if (!response) return; + *response = TerminateAck; + *((uint16_t *) (response + 2)) = htons(l = 4); + break; + + case Stopped: + initialise_restart_count(s, ipv6cp); + sendipv6cp(s, t); + if (*response == ConfigAck) + change_state(s, ipv6cp, AckSent); + else + change_state(s, ipv6cp, RequestSent); + + break; + + case RequestSent: + if (*response == ConfigAck) + change_state(s, ipv6cp, AckSent); + + break; + + case AckReceived: + if (*response == ConfigAck) + ipv6cp_open(s, t); + + break; + + case Opened: + initialise_restart_count(s, ipv6cp); + sendipv6cp(s, t); + /* fallthrough */ + + case AckSent: + if (*response == ConfigAck) + change_state(s, ipv6cp, AckSent); + else + change_state(s, ipv6cp, RequestSent); + + break; + + default: + LOG(2, s, t, "IPV6CP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipv6cp)); + return; } + + LOG(3, s, t, "IPV6CP: send %s\n", ppp_code(*response)); + tunnelsend(b, l + (response - b), t); + } + else if (*p == TerminateReq) + { + *p = TerminateAck; + q = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP); + if (!q) return; + LOG(3, s, t, "IPV6CP: send %s\n", ppp_code(*q)); + tunnelsend(b, l + (q - b), t); + change_state(s, ipv6cp, Stopped); + } + else if (*p != CodeRej) + { + ppp_code_rej(s, t, PPPIPV6CP, "IPV6CP", p, l, b, sizeof(b)); } } @@ -827,7 +1327,7 @@ void processipv6cp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t 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, uint8_t *p, uint16_t l) +void processipin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { in_addr_t ip; @@ -835,6 +1335,13 @@ void processipin(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) LOG_HEX(5, "IP", p, l); + if (l < 20 || l < ntohl(*(uint32_t *)(p + 2))) + { + LOG(1, s, t, "IP packet too short %d\n", l); + STAT(tunnel_rx_errors); + return ; + } + ip = ntohl(*(uint32_t *)(p + 12)); if (l > MAXETHER) @@ -844,6 +1351,9 @@ void processipin(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) return ; } + if (session[s].ppp.phase != Network || session[s].ppp.ipcp != Opened) + return; + // no spoof (do sessionbyip to handled statically routed subnets) if (ip != session[s].ip && sessionbyip(htonl(ip)) != s) { @@ -855,6 +1365,14 @@ void processipin(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) if (session[s].filter_in && !ip_filter(p, l, session[s].filter_in - 1)) return; + // adjust MSS on SYN and SYN,ACK packets with options + if ((ntohs(*(uint16_t *) (p + 6)) & 0x1fff) == 0 && p[9] == IPPROTO_TCP) // first tcp fragment + { + int ihl = (p[0] & 0xf) * 4; // length of IP header + if (l >= ihl + 20 && (p[ihl + 13] & TCP_FLAG_SYN) && ((p[ihl + 12] >> 4) > 5)) + adjust_tcp_mss(s, t, p, l, p + ihl); + } + // Add on the tun header p -= 4; *(uint32_t *) p = htonl(PKTIP); @@ -884,28 +1402,33 @@ void processipin(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) return; } + p += 4; + l -= 4; + 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); + snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port); } - session[s].cin += l - 4; - session[s].total_cin += l - 4; - sess_local[s].cin += l - 4; - + increment_counter(&session[s].cin, &session[s].cin_wrap, l); + session[s].cin_delta += l; session[s].pin++; - eth_tx += l - 4; + + sess_local[s].cin += l; + sess_local[s].pin++; + + eth_tx += l; STAT(tun_tx_packets); - INC_STAT(tun_tx_bytes, l - 4); + INC_STAT(tun_tx_bytes, l); } // process IPv6 packet received // // This MUST be called with at least 4 byte behind 'p'. // (i.e. this routine writes to p[-4]). -void processipv6in(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) +void processipv6in(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { struct in6_addr ip; in_addr_t ipv4; @@ -924,6 +1447,9 @@ void processipv6in(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) return ; } + if (session[s].ppp.phase != Network || session[s].ppp.ipv6cp != Opened) + return; + // no spoof if (ipv4 != session[s].ip && memcmp(&config->ipv6_prefix, &ip, 8) && sessionbyipv6(ip) != s) { @@ -939,7 +1465,7 @@ void processipv6in(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) *(uint32_t *)(p + 34) == 0 && *(p + 38) == 0 && *(p + 39) == 2 && *(p + 40) == 133) { LOG(3, s, t, "Got IPv6 RS\n"); - send_ipv6_ra(t, s, &ip); + send_ipv6_ra(s, t, &ip); return; } @@ -972,21 +1498,26 @@ void processipv6in(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) return; } + p += 4; + l -= 4; + 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); + snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port); } - session[s].cin += l - 4; - session[s].total_cin += l - 4; - sess_local[s].cin += l - 4; - + increment_counter(&session[s].cin, &session[s].cin_wrap, l); + session[s].cin_delta += l; session[s].pin++; - eth_tx += l - 4; + + sess_local[s].cin += l; + sess_local[s].pin++; + + eth_tx += l; STAT(tun_tx_packets); - INC_STAT(tun_tx_bytes, l - 4); + INC_STAT(tun_tx_bytes, l); } // @@ -1006,19 +1537,24 @@ void send_ipin(sessionidt s, uint8_t *buf, int len) return; } + buf += 4; + len -= 4; + 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); + snoop_send_packet(buf, len, session[s].snoop_ip, session[s].snoop_port); } // Increment packet counters - session[s].cin += len - 4; - session[s].total_cin += len - 4; - sess_local[s].cin += len - 4; - + increment_counter(&session[s].cin, &session[s].cin_wrap, len); + session[s].cin_delta += len; session[s].pin++; - eth_tx += len - 4; + + sess_local[s].cin += len; + sess_local[s].pin++; + + eth_tx += len; STAT(tun_tx_packets); INC_STAT(tun_tx_bytes, len - 4); @@ -1026,65 +1562,140 @@ void send_ipin(sessionidt s, uint8_t *buf, int len) // Process CCP messages -void processccp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) +void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { - uint8_t b[MAXCONTROL]; + uint8_t b[MAXETHER]; uint8_t *q; CSTAT(processccp); LOG_HEX(5, "CCP", p, l); - switch (l > 1 ? *p : 0) + + if (session[s].ppp.phase < Network) { - case ConfigAck: - session[s].flags |= SF_CCP_ACKED; + LOG(2, s, t, "CCP %s ignored in %s phase\n", ppp_code(*p), ppp_phase(session[s].ppp.phase)); return; + } - case ConfigReq: - if (l < 6) // accept no compression + if (l < 1) + { + LOG(1, s, t, "Short CCP packet\n"); + STAT(tunnel_rx_errors); + } + + LOG(3, s, t, "CCP: recv %s\n", ppp_code(*p)); + if (*p == ConfigAck) + { + switch (session[s].ppp.ccp) { - *p = ConfigAck; + case RequestSent: + initialise_restart_count(s, ccp); + change_state(s, ccp, AckReceived); + break; + + case AckReceived: + case Opened: + LOG(2, s, t, "CCP: ConfigAck in state %s? Sending ConfigReq\n", ppp_state(session[s].ppp.ccp)); + sendccp(s, t); + change_state(s, ccp, RequestSent); + break; + + case AckSent: + LOG(3, s, t, "CCP: Opened\n"); + change_state(s, ccp, Opened); break; + + default: + LOG(2, s, t, "CCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ccp)); } + } + else if (*p == ConfigReq) + { + if (l < 6) // accept no compression + *p = ConfigAck; + else // compression requested--reject + *p = ConfigRej; + + q = makeppp(b, sizeof(b), p, l, s, t, PPPCCP); + if (!q) return; + + switch (session[s].ppp.ccp) + { + case Closed: + q = makeppp(b, sizeof(b), p, 2, s, t, PPPCCP); + if (!q) return; + *q = TerminateAck; + *((uint16_t *) (q + 2)) = htons(l = 4); + break; - // compression requested--reject - *p = ConfigRej; + case Stopped: + initialise_restart_count(s, ccp); + sendccp(s, t); + if (*q == ConfigAck) + change_state(s, ccp, AckSent); + else + change_state(s, ccp, RequestSent); - // send CCP request for no compression for our end if not negotiated - if (!(session[s].flags & SF_CCP_ACKED)) - initccp(t, s); + break; - break; + case RequestSent: + if (*q == ConfigAck) + change_state(s, ccp, AckSent); - case TerminateReq: - *p = TerminateAck; - break; + break; - default: - if (l > 1) - LOG(1, s, t, "Unexpected CCP request code %d\n", *p); - else - LOG(1, s, t, "Short CCP packet\n"); + case AckReceived: + if (*q == ConfigAck) + change_state(s, ccp, Opened); - STAT(tunnel_rx_errors); - return; - } + break; - if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP))) - return; + case Opened: + initialise_restart_count(s, ccp); + sendccp(s, t); + /* fallthrough */ + + case AckSent: + if (*q == ConfigAck) + change_state(s, ccp, AckSent); + else + change_state(s, ccp, RequestSent); + + break; - tunnelsend(b, l + (q - b), t); // send it + default: + LOG(2, s, t, "CCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ccp)); + return; + } + + LOG(3, s, t, "CCP: send %s\n", ppp_code(*q)); + tunnelsend(b, l + (q - b), t); + } + else if (*p == TerminateReq) + { + *p = TerminateAck; + q = makeppp(b, sizeof(b), p, l, s, t, PPPCCP); + if (!q) return; + LOG(3, s, t, "CCP: send %s\n", ppp_code(*q)); + tunnelsend(b, l + (q - b), t); + change_state(s, ccp, Stopped); + } + else if (*p != CodeRej) + { + ppp_code_rej(s, t, PPPCCP, "CCP", p, l, b, sizeof(b)); + } } -// send a CHAP PP packet -void sendchap(tunnelidt t, sessionidt s) +// send a CHAP challenge +void sendchap(sessionidt s, tunnelidt t) { - uint8_t b[MAXCONTROL]; - uint16_t r = session[s].radius; + uint8_t b[MAXETHER]; + uint16_t r; uint8_t *q; CSTAT(sendchap); + r = radiusnew(s); if (!r) { LOG(1, s, t, "No RADIUS to send challenge\n"); @@ -1094,8 +1705,6 @@ void sendchap(tunnelidt t, sessionidt s) LOG(1, s, t, "Send CHAP challenge\n"); - // new challenge - random_data(radius[r].auth, sizeof(radius[r].auth)); radius[r].chap = 1; // CHAP not PAP radius[r].id++; if (radius[r].state != RADIUSCHAP) @@ -1105,18 +1714,18 @@ void sendchap(tunnelidt t, sessionidt s) radius[r].retry = backoff(radius[r].try++); if (radius[r].try > 5) { - sessionshutdown(s, "Timeout CHAP", 3, 0); + sessionshutdown(s, "CHAP timeout.", 3, 0); STAT(tunnel_tx_errors); return ; } - q = makeppp(b, sizeof(b), 0, 0, t, s, PPPCHAP); + q = makeppp(b, sizeof(b), 0, 0, s, t, PPPCHAP); if (!q) return; *q = 1; // challenge q[1] = radius[r].id; // ID - q[4] = 16; // length + q[4] = 16; // value size (size of challenge) memcpy(q + 5, radius[r].auth, 16); // challenge - strcpy(q + 21, hostname); // our name + strcpy((char *) q + 21, hostname); // our name *(uint16_t *) (q + 2) = htons(strlen(hostname) + 21); // length tunnelsend(b, strlen(hostname) + 21 + (q - b), t); // send it } @@ -1124,7 +1733,7 @@ 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 -uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, tunnelidt t, sessionidt s, uint16_t mtype) +uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelidt t, uint16_t mtype) { if (size < 12) // Need more space than this!! { @@ -1165,40 +1774,85 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, tunnelidt t, sessionid return b; } -// Send initial LCP ConfigReq for PAP, set magic no. -void initlcp(tunnelidt t, sessionidt s) +static int add_lcp_auth(uint8_t *b, int size, int authtype) { - char b[500], *q; + int len = 0; + if ((authtype == AUTHCHAP && size < 5) || size < 4) + return 0; + + *b++ = 3; // Authentication-Protocol + if (authtype == AUTHCHAP) + { + len = *b++ = 5; // length + *(uint16_t *) b = htons(PPPCHAP); b += 2; + *b++ = 5; // MD5 + } + else if (authtype == AUTHPAP) + { + len = *b++ = 4; // length + *(uint16_t *) b = htons(PPPPAP); b += 2; + } + else + { + LOG(0, 0, 0, "add_lcp_auth called with unsupported auth type %d\n", authtype); + } - if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP))) + return len; +} + +// Send initial LCP ConfigReq for MRU, authentication type and magic no +void sendlcp(sessionidt s, tunnelidt t) +{ + uint8_t b[500], *q, *l; + int authtype = sess_local[s].lcp_authtype; + + if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPLCP))) return; - LOG(4, s, t, "Sending LCP ConfigReq for PAP\n"); - *q = ConfigReq; - *(uint8_t *)(q + 1) = (time_now % 255) + 1; // ID - *(uint16_t *)(q + 2) = htons(14); // Length - *(uint8_t *)(q + 4) = 5; - *(uint8_t *)(q + 5) = 6; - *(uint32_t *)(q + 6) = htonl(session[s].magic); - *(uint8_t *)(q + 10) = 3; - *(uint8_t *)(q + 11) = 4; - *(uint16_t *)(q + 12) = htons(PPPPAP); // PAP - - LOG_HEX(5, "PPPLCP", q, 14); - tunnelsend(b, (q - b) + 14, t); + LOG(3, s, t, "LCP: send ConfigReq%s%s%s\n", + authtype ? " (" : "", + authtype ? (authtype == AUTHCHAP ? "CHAP" : "PAP") : "", + authtype ? ")" : ""); + + l = q; + *l++ = ConfigReq; + *l++ = ++sess_local[s].lcp_ident; // ID + + l += 2; //Save space for length + + if (sess_local[s].ppp_mru) + { + *l++ = 1; *l++ = 4; // Maximum-Receive-Unit (length 4) + *(uint16_t *) l = htons(sess_local[s].ppp_mru); l += 2; + } + + if (authtype) + l += add_lcp_auth(l, sizeof(b) - (l - b), authtype); + + *l++ = 5; *l++ = 6; // Magic-Number (length 6) + *(uint32_t *) l = htonl(session[s].magic); + l += 4; + + *(uint16_t *)(q + 2) = htons(l - q); // Length + + LOG_HEX(5, "PPPLCP", q, l - q); + if (config->debug > 3) dumplcp(q, l - q); + + tunnelsend(b, (l - b), t); } // Send CCP request for no compression -static void initccp(tunnelidt t, sessionidt s) +void sendccp(sessionidt s, tunnelidt t) { - char b[500], *q; + uint8_t b[500], *q; - if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP))) + if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPCCP))) return; - LOG(4, s, t, "Sending CCP ConfigReq for no compression\n"); + LOG(3, s, t, "CCP: send ConfigReq (no compression)\n"); + *q = ConfigReq; - *(uint8_t *)(q + 1) = (time_now % 255) + 1; // ID + *(q + 1) = ++sess_local[s].lcp_ident; // ID *(uint16_t *)(q + 2) = htons(4); // Length LOG_HEX(5, "PPPCCP", q, 4);