X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/3efd4f877afa6dbf12370e0be76921cd0b1037df..3e92edac6a72ab10310f55abf54d7588cd993c4b:/ppp.c diff --git a/ppp.c b/ppp.c index dead47f..92349e4 100644 --- a/ppp.c +++ b/ppp.c @@ -1,6 +1,6 @@ // L2TPNS PPP Stuff -char const *cvs_id_ppp = "$Id: ppp.c,v 1.75 2005/08/24 23:44:08 bodea Exp $"; +char const *cvs_id_ppp = "$Id: ppp.c,v 1.82 2005/09/16 05:04:29 bodea Exp $"; #include #include @@ -88,7 +88,7 @@ void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) 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, s, t, PPPPAP); if (!p) return; @@ -300,7 +300,7 @@ static void dumplcp(uint8_t *p, int l) else if (length == 5) { int proto = ntohs(*(uint16_t *)(o + 2)); - int algo = *(uint8_t *)(o + 4); + 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"); } @@ -374,7 +374,7 @@ static void lcp_restart(sessionidt s) change_state(s, ccp, Dead); } -static uint8_t *ppp_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype, +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) @@ -397,7 +397,7 @@ static uint8_t *ppp_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype, return queued + option[1]; } -static uint8_t *ppp_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype, +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) { @@ -415,13 +415,13 @@ static uint8_t *ppp_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype, if (*nak_sent < config->ppp_max_failure) // reject queued return queued; - return ppp_rej(s, buf, blen, mtype, response, 0, packet, option); + return ppp_conf_rej(s, buf, blen, mtype, response, 0, packet, option); } if (!*response) { if (*nak_sent >= config->ppp_max_failure) - return ppp_rej(s, buf, blen, mtype, response, 0, packet, option); + 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) @@ -444,10 +444,35 @@ static uint8_t *ppp_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype, 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(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; @@ -521,7 +546,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) if (session[s].ppp.lcp == Opened) lcp_restart(s); - sendlcp(s, t, sess_local[s].lcp_authtype); + sendlcp(s, t); change_state(s, lcp, RequestSent); break; @@ -558,7 +583,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) break; LOG(3, s, t, " Remote requesting asyncmap. Rejecting.\n"); - q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, asyncmap, sizeof(asyncmap)); + q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, asyncmap, sizeof(asyncmap)); break; case 3: // Authentication-Protocol @@ -596,14 +621,14 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authprefer); if (alen < 2) break; // paranoia - q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2); + 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) { // alternate type alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authtypes & ~config->radius_authprefer); if (alen < 2) break; - q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2); + q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2); } break; @@ -621,7 +646,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) default: // Reject any unknown options LOG(3, s, t, " Rejecting unknown PPP LCP option %d\n", type); - q = ppp_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o); + q = ppp_conf_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o); } x -= length; o += length; @@ -651,7 +676,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) case Stopped: initialise_restart_count(s, lcp); - sendlcp(s, t, sess_local[s].lcp_authtype); + sendlcp(s, t); if (*response == ConfigAck) change_state(s, lcp, AckSent); else @@ -673,7 +698,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) case Opened: lcp_restart(s); - sendlcp(s, t, sess_local[s].lcp_authtype); + sendlcp(s, t); /* fallthrough */ case AckSent: @@ -694,7 +719,7 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) tunnelsend(b, l + (response - b), t); } - else if (*p == ConfigNak) + else if (*p == ConfigNak || *p == ConfigRej) { int x = l - 4; uint8_t *o = (p + 4); @@ -709,14 +734,24 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) switch (type) { case 1: // Maximum-Receive-Unit - session[s].mru = ntohs(*(uint16_t *)(o + 2)); - LOG(3, s, t, " Remote requested MRU of %u\n", session[s].mru); + if (*p == ConfigNak) + { + 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); + } + else + { + 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) @@ -737,11 +772,16 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) proto); } } + else + { + LOG(2, s, t, "LCP: remote rejected auth negotiation\n"); + authtype = 0; // shutdown + } break; default: - LOG(2, s, t, " Remote NAKed LCP type %u?\n", type); + LOG(2, s, t, "LCP: remote sent %s for type %u?\n", ppp_code(*p), type); break; } x -= length; @@ -777,17 +817,17 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) case RequestSent: case AckSent: initialise_restart_count(s, lcp); - sendlcp(s, t, sess_local[s].lcp_authtype); + 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, sess_local[s].lcp_authtype); + sendlcp(s, t); break; case Opened: lcp_restart(s); - sendlcp(s, t, sess_local[s].lcp_authtype); + sendlcp(s, t); break; default: @@ -813,16 +853,26 @@ void processlcp(sessionidt s, tunnelidt t, 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"); 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) @@ -841,24 +891,9 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { // Ignore it, last_packet time is set earlier than this. } - else + else if (*p != CodeRej) { - int code = *p; - int mru = session[s].mru; - if (!mru) - mru = DEFAULT_MRU; - - if (l > mru) l = mru; - - *p = CodeRej; - q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP); - if (!q) return; - - LOG(2, s, t, "Unexpected LCP code %s\n", ppp_code(code)); - LOG(3, s, t, "LCP: send %s\n", ppp_code(*q)); - if (config->debug > 3) dumplcp(q, l); - - tunnelsend(b, l + (q - b), t); + ppp_code_rej(s, t, PPPLCP, "LCP", p, l, b, sizeof(b)); } } @@ -886,7 +921,7 @@ static void ipcp_open(sessionidt s, tunnelidt t) // Process IPCP messages void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { - uint8_t b[MAXCONTROL]; + uint8_t b[MAXETHER]; uint8_t *q = 0; uint16_t hl; @@ -960,7 +995,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) if (memcmp(o + 2, &addr, (sizeof addr))) { uint8_t *oq = q; - q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr)); + 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); @@ -976,7 +1011,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) addr = htonl(session[s].dns1); if (memcmp(o + 2, &addr, (sizeof addr))) { - q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr)); + q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr)); if (!q) return; } @@ -988,7 +1023,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) addr = htonl(session[s].dns1); if (memcmp(o + 2, &addr, sizeof(addr))) { - q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr)); + q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr)); if (!q) return; } @@ -996,7 +1031,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) default: LOG(2, s, t, " Rejecting PPP IPCP Option type %d\n", *o); - q = ppp_rej(s, b, sizeof(b), PPPIPCP, &response, q, p, o); + q = ppp_conf_rej(s, b, sizeof(b), PPPIPCP, &response, q, p, o); if (!q) return; } @@ -1084,22 +1119,9 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) tunnelsend(b, l + (q - b), t); change_state(s, ipcp, Stopped); } - else + else if (*p != CodeRej) { - int code = *p; - int mru = session[s].mru; - if (!mru) - mru = DEFAULT_MRU; - - if (l > mru) l = mru; - - *p = CodeRej; - q = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP); - if (!q) return; - - LOG(2, s, t, "Unexpected IPCP code %s\n", ppp_code(code)); - LOG(3, s, t, "IPCP: send %s\n", ppp_code(*q)); - tunnelsend(b, l + (q - b), t); + ppp_code_rej(s, t, PPPIPCP, "IPCP", p, l, b, sizeof(b)); } } @@ -1118,7 +1140,7 @@ static void ipv6cp_open(sessionidt s, tunnelidt t) // Process IPV6CP messages void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { - uint8_t b[MAXCONTROL]; + uint8_t b[MAXETHER]; uint8_t *q = 0; uint16_t hl; @@ -1148,16 +1170,6 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) LOG(3, s, t, "IPV6CP: recv %s\n", ppp_code(*p)); - if (!config->ipv6_prefix.s6_addr[0]) - { - LOG(2, s, t, "IPV6CP: %s rejected (not configured)\n", ppp_code(*p)); - *p = ProtocolRej; - q = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP); - if (!q) return; - tunnelsend(b, l + (q - b), t); - return; - } - if (!session[s].ip) { LOG(3, s, t, "IPV6CP: no IPv4 address (IPCP in state %s)\n", ppp_state(session[s].ppp.ipcp)); @@ -1209,7 +1221,7 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) if (memcmp(o + 2, ident, sizeof(ident))) { - q = ppp_nak(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o, ident, sizeof(ident)); + q = ppp_conf_nak(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o, ident, sizeof(ident)); if (!q) return; } @@ -1217,7 +1229,7 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) default: LOG(2, s, t, " Rejecting PPP IPV6CP Option type %d\n", *o); - q = ppp_rej(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o); + q = ppp_conf_rej(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o); if (!q) return; } @@ -1305,22 +1317,9 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) tunnelsend(b, l + (q - b), t); change_state(s, ipv6cp, Stopped); } - else + else if (*p != CodeRej) { - int code = *p; - int mru = session[s].mru; - if (!mru) - mru = DEFAULT_MRU; - - if (l > mru) l = mru; - - *p = CodeRej; - q = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP); - if (!q) return; - - LOG(2, s, t, "Unexpected IPV6CP code %s\n", ppp_code(code)); - LOG(3, s, t, "IPV6CP: send %s\n", ppp_code(*q)); - tunnelsend(b, l + (q - b), t); + ppp_code_rej(s, t, PPPIPV6CP, "IPV6CP", p, l, b, sizeof(b)); } } @@ -1336,6 +1335,13 @@ void processipin(sessionidt s, tunnelidt t, 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) @@ -1359,6 +1365,14 @@ void processipin(sessionidt s, tunnelidt t, 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); @@ -1550,7 +1564,7 @@ void send_ipin(sessionidt s, uint8_t *buf, int len) // Process CCP messages 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); @@ -1666,29 +1680,16 @@ void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) tunnelsend(b, l + (q - b), t); change_state(s, ccp, Stopped); } - else + else if (*p != CodeRej) { - int code = *p; - int mru = session[s].mru; - if (!mru) - mru = DEFAULT_MRU; - - if (l > mru) l = mru; - - *p = CodeRej; - q = makeppp(b, sizeof(b), p, l, s, t, PPPCCP); - if (!q) return; - - LOG(2, s, t, "Unexpected CCP code %s\n", ppp_code(code)); - LOG(3, s, t, "CCP: send %s\n", ppp_code(*q)); - tunnelsend(b, l + (q - b), t); + ppp_code_rej(s, t, PPPCCP, "CCP", p, l, b, sizeof(b)); } } // send a CHAP challenge void sendchap(sessionidt s, tunnelidt t) { - uint8_t b[MAXCONTROL]; + uint8_t b[MAXETHER]; uint16_t r; uint8_t *q; @@ -1800,9 +1801,10 @@ static int add_lcp_auth(uint8_t *b, int size, int authtype) } // Send initial LCP ConfigReq for MRU, authentication type and magic no -void sendlcp(sessionidt s, tunnelidt t, int authtype) +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; @@ -1812,17 +1814,17 @@ void sendlcp(sessionidt s, tunnelidt t, int authtype) authtype ? (authtype == AUTHCHAP ? "CHAP" : "PAP") : "", authtype ? ")" : ""); - if (!session[s].mru) - session[s].mru = DEFAULT_MRU; - l = q; *l++ = ConfigReq; - *l++ = (time_now % 255) + 1; // ID + *l++ = ++sess_local[s].lcp_ident; // ID l += 2; //Save space for length - *l++ = 1; *l++ = 4; // Maximum-Receive-Unit (length 4) - *(uint16_t *) l = htons(session[s].mru); l += 2; + 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); @@ -1850,7 +1852,7 @@ void sendccp(sessionidt s, tunnelidt t) 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);