X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/998f1c564e1dc729325cf25f130eaeb9562e745f..2b5cae3b51b9b575d98acc611035b3dcf56c6d72:/ppp.c diff --git a/ppp.c b/ppp.c index b808e05..3408d86 100644 --- a/ppp.c +++ b/ppp.c @@ -1,6 +1,6 @@ // L2TPNS PPP Stuff -char const *cvs_id_ppp = "$Id: ppp.c,v 1.51 2005-05-07 11:57:53 bodea Exp $"; +char const *cvs_id_ppp = "$Id: ppp.c,v 1.61 2005-05-13 09:23:00 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; } { @@ -156,14 +157,16 @@ 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 +174,23 @@ 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 +199,8 @@ 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 @@ -347,7 +354,33 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) if (*p == ConfigAck) { - LOG(3, s, t, "LCP: Discarding ConfigAck\n"); + int x = l - 4; + uint8_t *o = (p + 4); + + LOG(3, s, t, "LCP: ConfigAck (%d bytes)...\n", l); + if (config->debug > 3) dumplcp(p, l); + + 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 == PPPCHAP && *(o + 4) == 5) + sendchap(t, s); + } + + break; + } + x -= length; + o += length; + } + session[s].flags |= SF_LCP_ACKED; } else if (*p == ConfigReq) @@ -397,13 +430,13 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) *q++ = 6; memset(q, 0, 4); // asyncmap 0 q += 4; - *((uint16_t *) (response + 2)) = htons(q - response); // LCP header length break; case 3: // Authentication-Protocol { int proto = ntohs(*(uint16_t *)(o + 2)); char proto_name[] = "0x0000"; + uint8_t *a; if (proto == PPPPAP) { @@ -436,26 +469,27 @@ 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 break; } break; @@ -487,31 +521,97 @@ void processlcp(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l) memcpy(q, o, length); q += length; - *((uint16_t *) (response + 2)) = htons(q - response); // LCP header length } x -= length; o += length; } - if (!response) + if (response) { - // Send back a ConfigAck - q = response = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); - if (!q) return; - *q = ConfigAck; + 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, t, s, PPPLCP); + if (!response) return; + *response = ConfigAck; } LOG(3, s, t, "Sending %s\n", ppp_lcp_type(*response)); - tunnelsend(b, l + (q - b), t); + tunnelsend(b, l + response - 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 = -1; + + 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 > 0) + 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); + } + } + + break; + + default: + LOG(2, s, t, " Remote NAKed LCP type %u?\n", type); + break; + } + x -= length; + o += length; + } + + if (!authtype) + { + sessionshutdown(s, "Unsupported authentication.", 3, 0); + return; + } + + if (authtype == -1) + authtype = config->radius_authprefer; + + sendlcp(t, s, authtype); } else if (*p == TerminateReq) { @@ -570,7 +670,6 @@ 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 ; } } @@ -1195,8 +1294,33 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, tunnelidt t, sessionid return b; } -// Send initial LCP ConfigReq for preferred authentication type, set magic no and MRU -void initlcp(tunnelidt t, sessionidt s) +static uint8_t *add_lcp_auth(uint8_t *b, int size, int authtype) +{ + if ((authtype == AUTHCHAP && size < 5) || size < 4) + return 0; + + *b++ = 3; // Authentication-Protocol + if (authtype == AUTHCHAP) + { + *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 + { + LOG(0, 0, 0, "add_lcp_auth called with unsupported auth type %d\n", authtype); + } + + 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; @@ -1204,7 +1328,7 @@ void initlcp(tunnelidt t, sessionidt s) return; LOG(4, s, t, "Sending LCP ConfigReq for %s\n", - config->radius_authprefer == AUTHCHAP ? "CHAP" : "PAP"); + authtype == AUTHCHAP ? "CHAP" : "PAP"); if (!session[s].mru) session[s].mru = DEFAULT_MRU; @@ -1213,21 +1337,12 @@ void initlcp(tunnelidt t, sessionidt s) *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++ = 3; // Authentication-Protocol - if (config->radius_authprefer == AUTHCHAP) - { - *l++ = 5; // length - *(uint16_t *) l = htons(PPPCHAP); l += 2; - *l++ = 5; // MD5 - } - else - { - *l++ = 4; // length - *(uint16_t *) l = htons(PPPPAP); 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);