X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/59b55de4d7768bf41f2dd928e214ef6d98eb3351..686d880172e3038a7dfd8ea81c7c05539a5ad18a:/ppp.c?ds=sidebyside diff --git a/ppp.c b/ppp.c index c665d74..9a76d33 100644 --- a/ppp.c +++ b/ppp.c @@ -1,6 +1,6 @@ // L2TPNS PPP Stuff -char const *cvs_id_ppp = "$Id: ppp.c,v 1.49 2005/05/07 08:17:25 bodea Exp $"; +char const *cvs_id_ppp = "$Id: ppp.c,v 1.54 2005/05/10 00:56:12 bodea Exp $"; #include #include @@ -24,6 +24,7 @@ extern time_t time_now; extern configt *config; static void initccp(tunnelidt t, sessionidt s); +static uint8_t *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) @@ -40,7 +41,7 @@ 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); sessionshutdown(s, "Short PAP packet.", 3, 0); - return ; + return; } if ((hl = ntohs(*(uint16_t *) (p + 2))) > l) @@ -48,7 +49,7 @@ void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) LOG(1, s, t, "Length mismatch PAP %u/%u\n", hl, l); STAT(tunnel_rx_errors); sessionshutdown(s, "PAP length mismatch.", 3, 0); - return ; + return; } l = hl; @@ -57,7 +58,7 @@ 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); sessionshutdown(s, "Unexpected PAP code.", 3, 0); - return ; + return; } { @@ -149,6 +150,7 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) { LOG(1, s, t, "Unexpected CHAP message\n"); STAT(tunnel_rx_errors); + sessionshutdown(s, "Unexpected CHAP message.", 3, 0); return; } @@ -156,14 +158,16 @@ void processchap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) { 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; @@ -171,20 +175,23 @@ 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; } 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; @@ -193,7 +200,8 @@ 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 @@ -285,7 +293,7 @@ static void dumplcp(uint8_t *p, int l) { int proto = ntohs(*(uint16_t *)(o + 2)); int algo = *(uint8_t *)(o + 4); - LOG(4, 0, 0, " %s 0x%x 0x%x (%s)\n", lcp_types[type], proto, algo, + LOG(4, 0, 0, " %s 0x%x 0x%x (%s)\n", lcp_type(type), proto, algo, (proto == PPPCHAP && algo == 5) ? "CHAP MD5" : "UNSUPPORTED"); } else @@ -403,8 +411,8 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) case 3: // Authentication-Protocol { int proto = ntohs(*(uint16_t *)(o + 2)); - uint16_t wanted_proto; char proto_name[] = "0x0000"; + uint8_t *a; if (proto == PPPPAP) { @@ -437,23 +445,25 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) q += 4; } - if ((q - b + 5) > sizeof(b)) // 5 is the larger (CHAP+MD5) of the two NAKs + a = add_lcp_auth(q, sizeof(b) - (q - b), config->radius_authprefer); + if (!a) { LOG(2, s, t, "LCP overflow for %s ConfigNak.\n", proto_name); break; } - *q++ = type; - if (config->radius_authprefer == AUTHCHAP) - { - *q++ = 5; - *(uint16_t *) q = htons(PPPCHAP); q += 2; - *q++ = 5; // MD5 - } - else + q = a; + + if (config->radius_authtypes != config->radius_authprefer) { - *q++ = 4; - *(uint16_t *) q = htons(PPPPAP); q += 2; + a = add_lcp_auth(q, sizeof(b) - (q - b), config->radius_authtypes & ~config->radius_authprefer); + if (!a) + { + LOG(2, s, t, "LCP overflow for %s ConfigNak.\n", proto_name); + break; + } + + q = a; } *((uint16_t *) (response + 2)) = htons(q - response); // LCP header length @@ -506,13 +516,73 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) tunnelsend(b, l + (q - b), t); if (!(session[s].flags & SF_LCP_ACKED)) - initlcp(t, s); + sendlcp(t, s, config->radius_authprefer); } else if (*p == ConfigNak) { - LOG(1, s, t, "Remote end sent a ConfigNak. Ignoring\n"); + int x = l - 4; + uint8_t *o = (p + 4); + int authtype = 0; + + LOG(3, s, t, "LCP: ConfigNak (%d bytes)...\n", l); if (config->debug > 3) dumplcp(p, l); - return; + + 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(*(uint16_t *)(o + 2)); + LOG(3, s, t, " Remote requested MRU of %u\n", session[s].mru); + break; + + case 3: // Authentication-Protocol + if (authtype) + break; + + { + 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); + } + } + + if (!authtype) + { + sessionshutdown(s, "Unsupported authentication.", 3, 0); + return; + } + + break; + + default: + LOG(2, s, t, " Remote NAKed LCP type %u?\n", type); + break; + } + } + + if (!authtype) + authtype = config->radius_authprefer; + + sendlcp(t, s, authtype); } else if (*p == TerminateReq) { @@ -571,7 +641,6 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) { LOG(1, s, t, "Unexpected LCP code %d\n", *p); STAT(tunnel_rx_errors); - return ; } } @@ -1196,39 +1265,64 @@ 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 uint8_t *add_lcp_auth(uint8_t *b, int size, int authtype) { - char b[500], *q; - int size; - - if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP))) - return; + if ((authtype == AUTHCHAP && size < 5) || size < 4) + return 0; - 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; - if (config->radius_authprefer == AUTHCHAP) + *b++ = 3; // Authentication-Protocol + if (authtype == AUTHCHAP) { - *(uint8_t *)(q + 11) = 5; - *(uint16_t *)(q + 12) = htons(PPPCHAP); - *(uint8_t *)(q + 14) = 5; // MD5 - size = 15; + *b++ = 5; // length + *(uint16_t *) b = htons(PPPCHAP); b += 2; + *b++ = 5; // MD5 + } + else if (authtype == AUTHPAP) + { + *b++ = 4; // length + *(uint16_t *) b = htons(PPPPAP); b += 2; } else { - *(uint8_t *)(q + 11) = 4; - *(uint16_t *)(q + 12) = htons(PPPPAP); - size = 14; + LOG(0, 0, 0, "add_lcp_auth called with unsupported auth type %d\n", authtype); } - LOG_HEX(5, "PPPLCP", q, size); - tunnelsend(b, (q - b) + size, t); + return b; +} + +// Send initial LCP ConfigReq for MRU, authentication type and magic no +void sendlcp(tunnelidt t, sessionidt s, int authtype) +{ + char b[500], *q, *l; + + if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP))) + return; + + LOG(4, s, t, "Sending LCP ConfigReq for %s\n", + config->radius_authprefer == AUTHCHAP ? "CHAP" : "PAP"); + + if (!session[s].mru) + session[s].mru = DEFAULT_MRU; + + l = q; + *l++ = ConfigReq; + *l++ = (time_now % 255) + 1; // 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; + + 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); + tunnelsend(b, (l - b), t); } // Send CCP request for no compression