X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/667a8bc42060ce5d62ff93058586ce7925ba4449..af5792cb6a1ee10e11eb7439242834b967e98db8:/ppp.c diff --git a/ppp.c b/ppp.c index 590a52b..578273a 100644 --- a/ppp.c +++ b/ppp.c @@ -1,6 +1,6 @@ // L2TPNS PPP Stuff -char const *cvs_id_ppp = "$Id: ppp.c,v 1.81 2005/09/15 09:34:49 bodea Exp $"; +char const *cvs_id_ppp = "$Id: ppp.c,v 1.97 2006/03/27 03:01:08 bodea Exp $"; #include #include @@ -449,8 +449,7 @@ static void ppp_code_rej(sessionidt s, tunnelidt t, uint16_t proto, { uint8_t *q; int mru = session[s].mru; - - if (!mru) mru = MAXMRU; + if (mru < MINMTU) mru = MINMTU; if (mru > size) mru = size; l += 4; @@ -461,7 +460,7 @@ static void ppp_code_rej(sessionidt s, tunnelidt t, uint16_t proto, *q = CodeRej; *(q + 1) = ++sess_local[s].lcp_ident; - *(uint16_t *)(q + 2) = l; + *(uint16_t *)(q + 2) = htons(l); memcpy(q + 4, p, l - 4); LOG(2, s, t, "Unexpected %s code %s\n", pname, ppp_code(*p)); @@ -476,7 +475,6 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) { uint8_t b[MAXETHER]; uint8_t *q = NULL; - uint32_t magicno = 0; uint16_t hl; CSTAT(processlcp); @@ -500,7 +498,9 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) if (session[s].die) // going down... return; - LOG(*p == EchoReq ? 4 : 3, s, t, "LCP: recv %s\n", ppp_code(*p)); + LOG((*p == EchoReq || *p == EchoReply) ? 4 : 3, s, t, + "LCP: recv %s\n", ppp_code(*p)); + if (config->debug > 3) dumplcp(p, l); if (*p == ConfigAck) @@ -579,14 +579,15 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) case 1: // Maximum-Receive-Unit { uint16_t mru = ntohs(*(uint16_t *)(o + 2)); - if (!config->ppp_mru || mru <= config->ppp_mru) + if (mru >= MINMTU) { session[s].mru = mru; + cluster_send_session(s); break; } LOG(3, s, t, " Remote requesting MRU of %u. Rejecting.\n", mru); - mru = htons(config->ppp_mru); + mru = htons(MRU); q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, (uint8_t *) &mru, sizeof(mru)); } break; @@ -648,11 +649,8 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) } break; - case 5: // Magic-Number - magicno = ntohl(*(uint32_t *)(o + 2)); - break; - case 4: // Quality-Protocol + case 5: // Magic-Number case 7: // Protocol-Field-Compression case 8: // Address-And-Control-Field-Compression break; @@ -749,13 +747,13 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) case 1: // Maximum-Receive-Unit if (*p == ConfigNak) { - session[s].mru = 0; - LOG(3, s, t, " Remote requested MRU of %u; removing option\n", - ntohs(*(uint16_t *)(o + 2))); + if (length < 4) break; + 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 { - session[s].mru = 0; + sess_local[s].ppp_mru = 0; LOG(3, s, t, " Remote rejected MRU negotiation\n"); } @@ -767,14 +765,18 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) if (*p == ConfigNak) { - int proto = ntohs(*(uint16_t *)(o + 2)); + int proto; + + if (length < 4) break; + 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) + else if (proto == PPPCHAP && length > 4 && *(o + 4) == 5) { authtype = config->radius_authtypes & AUTHCHAP; LOG(3, s, t, " Remote requested CHAP authentication...%sing\n", @@ -794,9 +796,26 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) break; + case 5: // Magic-Number + session[s].magic = 0; + if (*p == ConfigNak) + { + if (length < 6) break; + session[s].magic = ntohl(*(uint32_t *)(o + 2)); + } + + if (session[s].magic) + LOG(3, s, t, " Remote requested magic-no %x\n", session[s].magic); + else + LOG(3, s, t, " Remote rejected magic-no\n"); + + cluster_send_session(s); + break; + default: LOG(2, s, t, "LCP: remote sent %s for type %u?\n", ppp_code(*p), type); - break; + sessionshutdown(s, "Unable to negotiate LCP.", 3, 0); + return; } x -= length; o += length; @@ -917,11 +936,17 @@ static void ipcp_open(sessionidt s, tunnelidt t) change_state(s, ipcp, Opened); - if (!session[s].walled_garden) + if (!(session[s].walled_garden || session[s].flags & SESSION_STARTED)) { uint16_t r = radiusnew(s); if (r) + { radiussend(r, RADIUSSTART); // send radius start + + // don't send further Start records if IPCP is restarted + session[s].flags |= SESSION_STARTED; + cluster_send_session(s); + } } // start IPv6 if configured and still in passive state @@ -942,7 +967,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) CSTAT(processipcp); LOG_HEX(5, "IPCP", p, l); - if (l < 5) + if (l < 4) { LOG(1, s, t, "Short IPCP %d bytes\n", l); STAT(tunnel_rx_errors); @@ -999,11 +1024,13 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) while (length > 2) { + if (!o[1] || o[1] > length) return; + switch (*o) { case 3: // ip address gotip++; // seen address - if (o[1] != 6 || o[1] > length) return; + if (o[1] != 6) return; addr = htonl(session[s].ip); if (memcmp(o + 2, &addr, (sizeof addr))) @@ -1020,7 +1047,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) break; case 129: // primary DNS - if (o[1] != 6 || o[1] > length) return; + if (o[1] != 6) return; addr = htonl(session[s].dns1); if (memcmp(o + 2, &addr, (sizeof addr))) @@ -1032,9 +1059,9 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) break; case 131: // secondary DNS - if (o[1] != 6 || o[1] > length) return; + if (o[1] != 6) return; - addr = htonl(session[s].dns1); + addr = htonl(session[s].dns2); 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)); @@ -1224,11 +1251,13 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) while (length > 2) { + if (!o[1] || o[1] > length) return; + switch (*o) { case 1: // interface identifier gotip++; // seen address - if (o[1] != 10 || o[1] > length) return; + if (o[1] != 10) return; *(uint32_t *) ident = htonl(session[s].ip); *(uint32_t *) (ident + 4) = 0; @@ -1349,6 +1378,13 @@ void processipin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l) LOG_HEX(5, "IP", p, l); + 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) @@ -1372,6 +1408,14 @@ 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); @@ -1730,15 +1774,12 @@ void sendchap(sessionidt s, tunnelidt t) } // 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, sessionidt s, tunnelidt t, uint16_t mtype) { if (size < 12) // Need more space than this!! { - static int backtrace_count = 0; LOG(0, s, t, "makeppp buffer too small for L2TP header (size=%d)\n", size); - log_backtrace(backtrace_count, 5) return NULL; } @@ -1746,12 +1787,12 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelid *(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)) + if (mtype == PPPLCP || !(session[s].flags & SESSION_ACFC)) { *(uint16_t *) b = htons(0xFF03); // HDLC header b += 2; } - if (mtype < 0x100 && session[s].l2tp_flags & SESSIONPFC) + if (mtype < 0x100 && session[s].flags & SESSION_PFC) *b++ = mtype; else { @@ -1761,9 +1802,7 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelid if (l + 12 > size) { - static int backtrace_count = 0; LOG(2, s, t, "makeppp would overflow buffer (size=%d, header+payload=%d)\n", size, l + 12); - log_backtrace(backtrace_count, 5) return NULL; } @@ -1799,7 +1838,7 @@ static int add_lcp_auth(uint8_t *b, int size, int authtype) return len; } -// Send initial LCP ConfigReq for MRU, authentication type and magic no +// Send LCP ConfigReq for MRU, authentication type and magic no void sendlcp(sessionidt s, tunnelidt t) { uint8_t b[500], *q, *l; @@ -1819,18 +1858,21 @@ void sendlcp(sessionidt s, tunnelidt t) l += 2; //Save space for length - if (session[s].mru) + if (sess_local[s].ppp_mru) { *l++ = 1; *l++ = 4; // Maximum-Receive-Unit (length 4) - *(uint16_t *) l = htons(session[s].mru); l += 2; + *(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; + if (session[s].magic) + { + *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 @@ -1838,6 +1880,7 @@ void sendlcp(sessionidt s, tunnelidt t) if (config->debug > 3) dumplcp(q, l - q); tunnelsend(b, (l - b), t); + restart_timer(s, lcp); } // Send CCP request for no compression @@ -1856,4 +1899,35 @@ void sendccp(sessionidt s, tunnelidt t) LOG_HEX(5, "PPPCCP", q, 4); tunnelsend(b, (q - b) + 4 , t); + restart_timer(s, ccp); +} + +// Reject unknown/unconfigured protocols +void protoreject(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l, uint16_t proto) +{ + + uint8_t buf[MAXETHER]; + uint8_t *q; + int mru = session[s].mru; + if (mru < MINMTU) mru = MINMTU; + if (mru > sizeof(buf)) mru = sizeof(buf); + + l += 6; + if (l > mru) l = mru; + + q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPLCP); + if (!q) return; + + *q = ProtocolRej; + *(q + 1) = ++sess_local[s].lcp_ident; + *(uint16_t *)(q + 2) = htons(l); + *(uint16_t *)(q + 4) = htons(proto); + memcpy(q + 6, p, l - 6); + + if (proto == PPPIPV6CP) + LOG(3, s, t, "LCP: send ProtocolRej (IPV6CP: not configured)\n"); + else + LOG(2, s, t, "LCP: sent ProtocolRej (0x%04X: unsupported)\n", proto); + + tunnelsend(buf, l + (q - buf), t); }