X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/2f5b811429a2690c2ce44d09cc571c3230420c1b..28dd7ee4432424d00361689156e8a366b8318a4a:/ppp.c diff --git a/ppp.c b/ppp.c index 4684947..4e19251 100644 --- a/ppp.c +++ b/ppp.c @@ -1,6 +1,6 @@ // L2TPNS PPP Stuff -char const *cvs_id_ppp = "$Id: ppp.c,v 1.33 2004-11-29 02:17:18 bodea Exp $"; +char const *cvs_id_ppp = "$Id: ppp.c,v 1.83 2005-09-16 05:20:32 bodea Exp $"; #include #include @@ -19,34 +19,37 @@ extern sessiont *session; extern radiust *radius; extern int tunfd; extern char hostname[]; -extern u32 eth_tx; +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, u8 *p, u16 l) +void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { - char user[129]; - char pass[129]; - u16 hl; + char user[MAXUSER]; + char pass[MAXPASS]; + uint16_t hl; + uint16_t r; - CSTAT(call_processpap); + CSTAT(processpap); LOG_HEX(5, "PAP", p, l); if (l < 4) { 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(*(u16 *) (p + 2))) > l) + 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; @@ -54,55 +57,64 @@ void processpap(tunnelidt t, sessionidt s, u8 *p, u16 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; } { - u8 *b = p; + uint8_t *b = p; b += 4; + user[0] = pass[0] = 0; if (*b && *b < sizeof(user)) + { memcpy(user, b + 1, *b); - user[*b] = 0; - b += 1 + *b; - if (*b && *b < sizeof(pass)) - memcpy(pass, b + 1, *b); - pass[*b] = 0; + user[*b] = 0; + b += 1 + *b; + if (*b && *b < sizeof(pass)) + { + memcpy(pass, b + 1, *b); + pass[*b] = 0; + } + } 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 - u8 b[MAXCONTROL]; - u8 id = p[1]; - u8 *p = makeppp(b, sizeof(b), 0, 0, t, s, PPPPAP); + uint8_t b[MAXETHER]; + uint8_t id = p[1]; + uint8_t *p = makeppp(b, sizeof(b), 0, 0, s, t, PPPPAP); if (!p) 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 + *(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 - u16 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); @@ -121,43 +133,35 @@ void processpap(tunnelidt t, sessionidt s, u8 *p, u16 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, u8 *p, u16 l) +void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { - u16 r; - u16 hl; + uint16_t r; + uint16_t hl; - CSTAT(call_processchap); + CSTAT(processchap); LOG_HEX(5, "CHAP", p, l); - r = session[s].radius; - if (!r) - { - LOG(1, s, t, "Unexpected CHAP message\n"); - -// FIXME: Need to drop the session here. - - 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(*(u16 *) (p + 2))) > l) + 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; @@ -165,20 +169,37 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 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; @@ -187,7 +208,8 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 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 @@ -224,29 +246,13 @@ void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l) radiussend(r, RADIUSAUTH); } -static char *ppp_lcp_types[] = { - NULL, - "ConfigReq", - "ConfigAck", - "ConfigNak", - "ConfigRej", - "TerminateReq", - "TerminateAck", - "CodeRej", - "ProtocolRej", - "EchoReq", - "EchoReply", - "DiscardRequest", - "IdentRequest", -}; - -static void dumplcp(u8 *p, int l) +static void dumplcp(uint8_t *p, int l) { int x = l - 4; - u8 *o = (p + 4); + 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_types[(int)*p], ntohs( ((u16 *) 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; @@ -271,48 +277,54 @@ static void dumplcp(u8 *p, int l) { case 1: // Maximum-Receive-Unit if (length == 4) - LOG(4, 0, 0, " %s %d\n", lcp_types[type], ntohs(*(u16 *)(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_types[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) { - u32 asyncmap = ntohl(*(u32 *)(o + 2)); - LOG(4, 0, 0, " %s %x\n", lcp_types[type], asyncmap); + uint32_t asyncmap = ntohl(*(uint32_t *)(o + 2)); + LOG(4, 0, 0, " %s %x\n", ppp_lcp_option(type), asyncmap); } else - LOG(4, 0, 0, " %s odd length %d\n", lcp_types[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(*(u16 *)(o + 2)); - LOG(4, 0, 0, " %s 0x%x (%s)\n", lcp_types[type], proto, - proto == PPPCHAP ? "CHAP" : - proto == PPPPAP ? "PAP" : "UNKNOWN"); + int proto = ntohs(*(uint16_t *)(o + 2)); + 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_types[type], length); + LOG(4, 0, 0, " %s odd length %d\n", ppp_lcp_option(type), length); break; case 4: // Quality-Protocol { - u32 qp = ntohl(*(u32 *)(o + 2)); - LOG(4, 0, 0, " %s %x\n", lcp_types[type], qp); + uint32_t qp = ntohl(*(uint32_t *)(o + 2)); + LOG(4, 0, 0, " %s %x\n", ppp_lcp_option(type), qp); } break; case 5: // Magic-Number if (length == 6) { - u32 magicno = ntohl(*(u32 *)(o + 2)); - LOG(4, 0, 0, " %s %x\n", lcp_types[type], magicno); + uint32_t magicno = ntohl(*(uint32_t *)(o + 2)); + LOG(4, 0, 0, " %s %x\n", ppp_lcp_option(type), magicno); } else - LOG(4, 0, 0, " %s odd length %d\n", lcp_types[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_types[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); @@ -323,15 +335,149 @@ static void dumplcp(u8 *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, u8 *p, u16 l) +void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { - u8 b[MAXCONTROL]; - u8 *q = NULL; - u32 magicno = 0; - u16 hl; + uint8_t b[MAXETHER]; + uint8_t *q = NULL; + uint32_t magicno = 0; + uint16_t hl; - CSTAT(call_processlcp); + CSTAT(processlcp); LOG_HEX(5, "LCP", p, l); if (l < 4) @@ -341,7 +487,7 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l) return ; } - if ((hl = ntohs(*(u16 *) (p + 2))) > l) + if ((hl = ntohs(*(uint16_t *) (p + 2))) > l) { LOG(1, s, t, "Length mismatch LCP %u/%u\n", hl, l); STAT(tunnel_rx_errors); @@ -349,96 +495,148 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 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; - u8 *o = (p + 4); - u8 response = 0; - - LOG(3, s, t, "LCP: ConfigReq (%d bytes)...\n", l); - if (config->debug > 3) dumplcp(p, l); + uint8_t *o = (p + 4); + uint8_t *response = 0; + static uint8_t asyncmap[4] = { 0, 0, 0, 0 }; // all zero + static uint8_t authproto[5]; 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 - session[s].mru = ntohs(*(u16 *)(o + 2)); + session[s].mru = ntohs(*(uint16_t *)(o + 2)); break; 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 = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP); - if (!q) break; - response = *q++ = ConfigNak; - } - - if ((q - b + 11) > sizeof(b)) - { - LOG(2, s, t, "LCP overflow for asyncmap ConfigNak.\n"); + if (!ntohl(*(uint32_t *)(o + 2))) // all bits zero is OK break; - } - *q++ = type; - *q++ = 6; - memset(q, 0, 4); // asyncmap 0 - q += 4; + 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(*(u16 *)(o + 2)); + 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 = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP); - if (!q) break; - response = *q++ = ConfigNak; - } + 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); - *(u16 *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead - q += length; + break; } break; case 5: // Magic-Number - magicno = ntohl(*(u32 *)(o + 2)); + magicno = ntohl(*(uint32_t *)(o + 2)); break; case 4: // Quality-Protocol @@ -447,120 +645,287 @@ void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 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 = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP); - if (!q) return; - response = *q++ = ConfigRej; + 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; + 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 = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); - if (!q) return; - response = *q = ConfigAck; + sessionshutdown(s, "Unsupported authentication.", 3, 0); + return; } - LOG(3, s, t, "Sending %s\n", ppp_lcp_types[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."); + sessionshutdown(s, "Remote end closed connection.", 3, 0); } else if (*p == TerminateAck) { - sessionshutdown(s, "Connection closed."); + sessionshutdown(s, "Connection closed.", 3, 0); + } + else if (*p == ProtocolRej) + { + 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"); + change_state(s, ipv6cp, Closed); + } + else + { + 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 - *(u32 *) (p + 4) = htonl(session[s].magic); // our magic number - q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); + *(uint32_t *) (p + 4) = htonl(session[s].magic); // our magic number + 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 u8 *findppp(u8 *b, u8 mtype) +static void ipcp_open(sessionidt s, tunnelidt t) { - u16 l = ntohs(*(u16 *) (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, u8 *p, u16 l) +void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { - u16 hl; + uint8_t b[MAXETHER]; + uint8_t *q = 0; + uint16_t hl; - CSTAT(call_processipcp); + CSTAT(processipcp); LOG_HEX(5, "IPCP", p, l); if (l < 5) @@ -570,7 +935,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l) return ; } - if ((hl = ntohs(*(u16 *) (p + 2))) > l) + if ((hl = ntohs(*(uint16_t *) (p + 2))) > l) { LOG(1, s, t, "Length mismatch IPCP %u/%u\n", hl, l); STAT(tunnel_rx_errors); @@ -578,118 +943,383 @@ void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 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 - u16 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 + case RequestSent: + initialise_restart_count(s, ipcp); + change_state(s, ipcp, AckReceived); + break; + + 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; + + case AckSent: + ipcp_open(s, t); + break; + + default: + LOG(2, s, t, "IPCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ipcp)); } - session[s].flags |= SF_IPCP_ACKED; + } + else if (*p == ConfigReq) + { + uint8_t *response = 0; + uint8_t *o = p + 4; + int length = l - 4; + int gotip = 0; + in_addr_t addr; - LOG(3, s, t, "IPCP Acked, session is now active\n"); + while (length > 2) + { + switch (*o) + { + case 3: // ip address + gotip++; // seen address + if (o[1] != 6 || o[1] > length) return; - // clear LCP_ACKED/CCP_ACKED flag for possible fast renegotiaion for routers - session[s].flags &= ~(SF_LCP_ACKED|SF_CCP_ACKED); + addr = htonl(session[s].ip); + if (memcmp(o + 2, &addr, (sizeof addr))) + { + 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; + } + } - return; + 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))) + { + q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr)); + if (!q) return; + } + + 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))) + { + 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; + } + + 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); } - if (*p != ConfigReq) + else if (*p == TerminateReq) { - LOG(1, s, t, "Unexpected IPCP code %d\n", *p); + *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(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) +{ + uint8_t b[MAXETHER]; + uint8_t *q = 0; + uint16_t hl; + + CSTAT(processipv6cp); + + LOG_HEX(5, "IPV6CP", p, l); + if (l < 4) + { + LOG(1, s, t, "Short IPV6CP %d bytes\n", l); STAT(tunnel_rx_errors); return ; } - LOG(4, s, t, "IPCP ConfigReq received\n"); - if (!session[s].ip) + if ((hl = ntohs(*(uint16_t *) (p + 2))) > l) + { + LOG(1, s, t, "Length mismatch IPV6CP %u/%u\n", hl, l); + STAT(tunnel_rx_errors); + return ; + } + l = hl; + + if (session[s].ppp.phase < Network) { - LOG(3, s, t, "Waiting on radius reply\n"); - return; // have to wait on RADIUS reply + LOG(2, s, t, "IPV6CP %s ignored in %s phase\n", ppp_code(*p), ppp_phase(session[s].ppp.phase)); + return; } - // form a config reply quoting the IP in the session + + LOG(3, s, t, "IPV6CP: recv %s\n", ppp_code(*p)); + + if (!session[s].ip) { - u8 b[MAXCONTROL]; - u8 *i, - *q; + LOG(3, s, t, "IPV6CP: no IPv4 address (IPCP in state %s)\n", ppp_state(session[s].ppp.ipcp)); + return; // need IPCP to complete... + } - q = p + 4; - i = p + l; - while (q < i && q[1]) + if (*p == ConfigAck) + { + switch (session[s].ppp.ipv6cp) { - if (*q != 0x81 && *q != 0x83 && *q != 3) - 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) - { - // reject - u16 n = 4; - i = p + l; - if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP))) - return; + } + else if (*p == ConfigReq) + { + uint8_t *response = 0; + uint8_t *o = p + 4; + int length = l - 4; + int gotip = 0; + uint8_t ident[8]; - *q = ConfigRej; - p += 4; - while (p < i && p[1]) + while (length > 2) + { + switch (*o) { - if (*p != 0x81 && *p != 0x83 && *p != 3) + 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, "IPCP 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; } - *(u16 *) (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; - if ((i = findppp(p, 0x81))) // Primary DNS address - { - if (*(u32 *) (i + 2) != htonl(session[s].dns1)) - { - *(u32 *) (i + 2) = htonl(session[s].dns1); - *p = ConfigNak; - LOG(5, s, t, " DNS1 = %s\n", fmtaddr(session[s].dns1, 0)); - } - } - if ((i = findppp(p, 0x83))) // Secondary DNS address (TBA, is it) - { - if (*(u32 *) (i + 2) != htonl(session[s].dns2)) - { - *(u32 *) (i + 2) = htonl(session[s].dns2); - *p = ConfigNak; - LOG(5, s, t, " DNS2 = %s\n", fmtaddr(session[s].dns2, 0)); - } - } - 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 (*(u32 *) (i + 2) != htonl(session[s].ip)) - { - *(u32 *) (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; + 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); - tunnelsend(b, l + (q - b), t); // send it + 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)); } } @@ -697,15 +1327,22 @@ 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(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { - ipt ip; + in_addr_t ip; - CSTAT(call_processipin); + CSTAT(processipin); LOG_HEX(5, "IP", p, l); - ip = ntohl(*(u32 *)(p + 12)); + if (l < 20) + { + 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) { @@ -714,6 +1351,9 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 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) { @@ -725,17 +1365,29 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 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; - *(u32 *)p = htonl(0x00000800); + *(uint32_t *) p = htonl(PKTIP); l += 4; - if (session[s].tbf_in && !config->cluster_iam_master) { // Are we throttled and a slave? - master_throttle_packet(session[s].tbf_in, p, l); // Pass it to the master for handling. + // Are we throttled and a slave? + if (session[s].tbf_in && !config->cluster_iam_master) { + // Pass it to the master for handling. + master_throttle_packet(session[s].tbf_in, p, l); return; } - if (session[s].tbf_in && config->cluster_iam_master) { // Are we throttled and a master?? actually handle the throttled packets. + // Are we throttled and a master?? + if (session[s].tbf_in && config->cluster_iam_master) { + // Actually handle the throttled packets. tbf_queue_packet(session[s].tbf_in, p, l); return; } @@ -750,28 +1402,129 @@ void processipin(tunnelidt t, sessionidt s, u8 *p, u16 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_count[s].cin += l - 4; + increment_counter(&session[s].cin, &session[s].cin_wrap, l); + session[s].cin_delta += l; + session[s].pin++; + + sess_local[s].cin += l; + sess_local[s].pin++; + eth_tx += l; + + STAT(tun_tx_packets); + 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(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) +{ + struct in6_addr ip; + in_addr_t ipv4; + + CSTAT(processipv6in); + + LOG_HEX(5, "IPv6", p, l); + + ip = *(struct in6_addr *) (p + 8); + ipv4 = ntohl(*(uint32_t *)(p + 16)); + + if (l > MAXETHER) + { + LOG(1, s, t, "IP packet too long %d\n", l); + STAT(tunnel_rx_errors); + 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) + { + char str[INET6_ADDRSTRLEN]; + LOG(5, s, t, "Dropping packet with spoofed IP %s\n", + inet_ntop(AF_INET6, &ip, str, INET6_ADDRSTRLEN)); + return; + } + + // Check if it's a Router Solicition message. + if (*(p + 6) == 58 && *(p + 7) == 255 && *(p + 24) == 0xFF && *(p + 25) == 2 && + *(uint32_t *)(p + 26) == 0 && *(uint32_t *)(p + 30) == 0 && + *(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(s, t, &ip); + return; + } + + // Add on the tun header + p -= 4; + *(uint32_t *) p = htonl(PKTIPV6); + l += 4; + + // Are we throttled and a slave? + if (session[s].tbf_in && !config->cluster_iam_master) { + // Pass it to the master for handling. + master_throttle_packet(session[s].tbf_in, p, l); + return; + } + + // Are we throttled and a master?? + if (session[s].tbf_in && config->cluster_iam_master) { + // Actually handle the throttled packets. + tbf_queue_packet(session[s].tbf_in, p, l); + return; + } + + // send to ethernet + if (tun_write(p, l) < 0) + { + STAT(tun_tx_errors); + LOG(0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n", + l, strerror(errno), tunfd, p); + + return; + } + + p += 4; + 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); + } + + 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); } // // Helper routine for the TBF filters. // Used to send queued data in from the user. // -void send_ipin(sessionidt s, u8 *buf, int len) +void send_ipin(sessionidt s, uint8_t *buf, int len) { LOG_HEX(5, "IP in throttled", buf, len); @@ -784,19 +1537,24 @@ void send_ipin(sessionidt s, u8 *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_count[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); @@ -804,106 +1562,178 @@ void send_ipin(sessionidt s, u8 *buf, int len) // Process CCP messages -void processccp(tunnelidt t, sessionidt s, u8 *p, u16 l) +void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { - u8 b[MAXCONTROL]; - u8 *q; + uint8_t b[MAXETHER]; + uint8_t *q; - CSTAT(call_processccp); + 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; - // compression requested--reject - *p = ConfigRej; + q = makeppp(b, sizeof(b), p, l, s, t, PPPCCP); + if (!q) return; - // send CCP request for no compression for our end if not negotiated - if (!(session[s].flags & SF_CCP_ACKED)) - initccp(t, s); + 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; - break; + case Stopped: + initialise_restart_count(s, ccp); + sendccp(s, t); + if (*q == ConfigAck) + change_state(s, ccp, AckSent); + else + change_state(s, ccp, RequestSent); - 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 RequestSent: + if (*q == ConfigAck) + change_state(s, ccp, AckSent); - STAT(tunnel_rx_errors); - return; - } + break; - if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP))) - return; + case AckReceived: + if (*q == ConfigAck) + change_state(s, ccp, Opened); + + break; + + 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; + + default: + LOG(2, s, t, "CCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.ccp)); + return; + } - tunnelsend(b, l + (q - b), t); // send it + 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) { - u8 b[MAXCONTROL]; - u16 r = session[s].radius; - u8 *q; + uint8_t b[MAXETHER]; + uint16_t r; + uint8_t *q; - CSTAT(call_sendchap); + CSTAT(sendchap); + r = radiusnew(s); if (!r) { LOG(1, s, t, "No RADIUS to send challenge\n"); STAT(tunnel_tx_errors); - return ; + return; } + LOG(1, s, t, "Send CHAP challenge\n"); - { - // new challenge - int n; - for (n = 0; n < 15; n++) - radius[r].auth[n] = rand(); - } + radius[r].chap = 1; // CHAP not PAP radius[r].id++; if (radius[r].state != RADIUSCHAP) radius[r].try = 0; + radius[r].state = RADIUSCHAP; radius[r].retry = backoff(radius[r].try++); if (radius[r].try > 5) { - sessionshutdown(s, "Timeout CHAP"); + 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 - *(u16 *) (q + 2) = htons(strlen(hostname) + 21); // length + 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 } // 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) +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!! { @@ -913,20 +1743,20 @@ u8 *makeppp(u8 *b, int size, u8 *p, int l, tunnelidt t, sessionidt s, u16 mtype) 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 + *(uint16_t *) (b + 0) = htons(0x0002); // L2TP with no options + *(uint16_t *) (b + 2) = htons(tunnel[t].far); // tunnel + *(uint16_t *) (b + 4) = htons(session[s].far); // session b += 6; if (mtype == PPPLCP || !(session[s].l2tp_flags & SESSIONACFC)) { - *(u16 *) b = htons(0xFF03); // HDLC header + *(uint16_t *) b = htons(0xFF03); // HDLC header b += 2; } if (mtype < 0x100 && session[s].l2tp_flags & SESSIONPFC) *b++ = mtype; else { - *(u16 *) b = htons(mtype); + *(uint16_t *) b = htons(mtype); b += 2; } @@ -944,41 +1774,86 @@ u8 *makeppp(u8 *b, int size, u8 *p, int l, tunnelidt t, sessionidt s, u16 mtype) 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) +{ + 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); + } + + return len; +} + +// Send initial LCP ConfigReq for MRU, authentication type and magic no +void sendlcp(sessionidt s, tunnelidt t) { - char b[500], *q; + uint8_t b[500], *q, *l; + int authtype = sess_local[s].lcp_authtype; - if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP))) + if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPLCP))) return; - 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 - *(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(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; - *(u8 *)(q + 1) = (time_now % 255) + 1; // ID - *(u16 *)(q + 2) = htons(4); // Length + *(q + 1) = ++sess_local[s].lcp_ident; // ID + *(uint16_t *)(q + 2) = htons(4); // Length LOG_HEX(5, "PPPCCP", q, 4); tunnelsend(b, (q - b) + 4 , t);