X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/0c736f6fe826c7fd17dd6cee106c205c06a93916..f5fb6dea8634c6c3d41857225c4b26d4c0f1c960:/ppp.c diff --git a/ppp.c b/ppp.c index e4f4e81..c69c603 100644 --- a/ppp.c +++ b/ppp.c @@ -1,5 +1,6 @@ // L2TPNS PPP Stuff -// $Id: ppp.c,v 1.3 2004-03-05 00:22:06 fred_nerk Exp $ + +char const *cvs_id_ppp = "$Id: ppp.c,v 1.38 2004-11-30 19:34:57 bodea Exp $"; #include #include @@ -10,45 +11,52 @@ #include "constants.h" #include "plugin.h" #include "util.h" +#include "tbf.h" +#include "cluster.h" extern tunnelt *tunnel; extern sessiont *session; extern radiust *radius; -extern int tapfd; -extern char hostname[1000]; -extern struct Tstats *_statistics; -extern unsigned long eth_tx; +extern int tunfd; +extern char hostname[]; +extern u32 eth_tx; extern time_t time_now; -extern struct configt *config; +extern configt *config; + +static void initccp(tunnelidt t, sessionidt s); // Process PAP messages -void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) +void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l) { char user[129]; char pass[129]; + u16 hl; + + CSTAT(call_processpap); -#ifdef STAT_CALLS - STAT(call_processpap); -#endif - log_hex(5, "PAP", p, l); + LOG_HEX(5, "PAP", p, l); if (l < 4) { - log(1, 0, s, t, "Short PAP %u bytes", l); + LOG(1, s, t, "Short PAP %u bytes\n", l); STAT(tunnel_rx_errors); return ; } - if (*p != 1) + + if ((hl = ntohs(*(u16 *) (p + 2))) > l) { - log(1, 0, s, t, "Unexpected PAP code %d\n", *p); + LOG(1, s, t, "Length mismatch PAP %u/%u\n", hl, l); STAT(tunnel_rx_errors); return ; } - if (ntohs(*(u16 *) (p + 2)) > l) + l = hl; + + if (*p != 1) { - log(1, 0, s, t, "Length mismatch PAP %d/%d\n", ntohs(*(u16 *) (p + 2)), l); + LOG(1, s, t, "Unexpected PAP code %d\n", *p); STAT(tunnel_rx_errors); return ; } + { u8 *b = p; b += 4; @@ -59,42 +67,48 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) if (*b && *b < sizeof(pass)) memcpy(pass, b + 1, *b); pass[*b] = 0; - log(3, 0, s, t, "PAP login %s/%s\n", user, pass); + LOG(3, s, t, "PAP login %s/%s\n", user, pass); } if (session[s].ip || !session[s].radius) { // respond now, either no RADIUS available or already authenticated u8 b[MAXCONTROL]; u8 id = p[1]; - u8 *p = makeppp(b, 0, 0, t, s, PPPPAP); + u8 *p = makeppp(b, sizeof(b), 0, 0, t, s, 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 + *(u16 *) (p + 2) = htons(5); // length + p[4] = 0; // no message if (session[s].ip) { - log(3, session[s].ip, s, t, "%d Already an IP allocated: %s (%d)\n", getpid(), inet_toa(htonl(session[s].ip)), session[s].ip_pool_index); + 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, 0, s, t, "No radius session available to authenticate session...\n"); + LOG(1, s, t, "No radius session available to authenticate session...\n"); } - log(3, 0, s, t, "Fallback response to PAP (%s)\n", (session[s].ip) ? "ACK" : "NAK"); + 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 - u8 r = session[s].radius; + { + // 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); if (!packet.continue_auth) { - log(3, 0, s, t, "A plugin rejected PRE_AUTH\n"); + LOG(3, s, t, "A plugin rejected PRE_AUTH\n"); if (packet.username) free(packet.username); if (packet.password) free(packet.password); return; @@ -107,56 +121,71 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) free(packet.password); radius[r].id = p[1]; - log(3, 0, 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(tunnelidt t, sessionidt s, u8 *p, u16 l) { - u8 r; - u16 len; + u16 r; + u16 hl; -#ifdef STAT_CALLS - STAT(call_processchap); -#endif - log_hex(5, "CHAP", p, l); + CSTAT(call_processchap); + + LOG_HEX(5, "CHAP", p, l); r = session[s].radius; if (!r) { - log(1, 0, s, t, "Unexpected CHAP message\n"); + LOG(1, s, t, "Unexpected CHAP message\n"); + +// FIXME: Need to drop the session here. + STAT(tunnel_rx_errors); return; } - if (*p != 2) + + if (l < 4) { - log(1, 0, s, t, "Unexpected CHAP response code %d\n", *p); + LOG(1, s, t, "Short CHAP %u bytes\n", l); STAT(tunnel_rx_errors); - return; + return ; } - if (p[1] != radius[r].id) + + if ((hl = ntohs(*(u16 *) (p + 2))) > l) { - log(1, 0, s, t, "Wrong CHAP response ID %d (should be %d) (%d)\n", p[1], radius[r].id, r); + LOG(1, s, t, "Length mismatch CHAP %u/%u\n", hl, l); STAT(tunnel_rx_errors); return ; } - len = ntohs(*(u16 *) (p + 2)); - if (len > l) + l = hl; + + if (*p != 2) + { + LOG(1, s, t, "Unexpected CHAP response code %d\n", *p); + STAT(tunnel_rx_errors); + return; + } + if (p[1] != radius[r].id) { - log(1, 0, s, t, "Bad CHAP length %d\n", len); + 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 ; } - if (p[4] != 16) + + if (l < 5 || p[4] != 16) { - log(1, 0, s, t, "Bad CHAP response length %d\n", p[4]); + LOG(1, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]); STAT(tunnel_rx_errors); return ; } - if (len - 21 >= sizeof(session[s].user)) + + l -= 5; + p += 5; + if (l < 16 || l - 16 >= sizeof(session[s].user)) { - log(1, 0, s, t, "CHAP user too long %d\n", len - 21); + LOG(1, s, t, "CHAP user too long %d\n", l - 16); STAT(tunnel_rx_errors); return ; } @@ -165,15 +194,19 @@ void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l) { struct param_pre_auth packet = { &tunnel[t], &session[s], NULL, NULL, PPPCHAP, 1 }; - packet.username = calloc(len-20, 1); - packet.password = calloc(16, 1); - memcpy(packet.username, p + 21, len - 21); - memcpy(packet.password, p + 5, 16); + packet.password = calloc(17, 1); + memcpy(packet.password, p, 16); + + p += 16; + l -= 16; + + packet.username = calloc(l + 1, 1); + memcpy(packet.username, p, l); run_plugins(PLUGIN_PRE_AUTH, &packet); if (!packet.continue_auth) { - log(3, 0, s, t, "A plugin rejected PRE_AUTH\n"); + LOG(3, s, t, "A plugin rejected PRE_AUTH\n"); if (packet.username) free(packet.username); if (packet.password) free(packet.password); return; @@ -187,11 +220,11 @@ void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l) } radius[r].chap = 1; + LOG(3, s, t, "CHAP login %s\n", session[s].user); radiussend(r, RADIUSAUTH); - log(3, 0, s, t, "CHAP login %s\n", session[s].user); } -char *ppp_lcp_types[] = { +static char *ppp_lcp_types[] = { NULL, "ConfigReq", "ConfigAck", @@ -204,31 +237,32 @@ char *ppp_lcp_types[] = { "EchoReq", "EchoReply", "DiscardRequest", + "IdentRequest", }; -void dumplcp(char *p, int l) +static void dumplcp(u8 *p, int l) { - signed int x = l - 3; - char *o = (p + 3); + int x = l - 4; + u8 *o = (p + 4); - log_hex(5, "PPP LCP Packet", p, l); - log(4, 0, 0, 0, "PPP LCP Packet type %d (%s)\n", *p, ppp_lcp_types[(int)*p]); - log(4, 0, 0, 0, "Length: %d\n", l); + 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, "Length: %d\n", l); if (*p != ConfigReq && *p != ConfigRej && *p != ConfigAck) return; while (x > 2) { - int type = *(u8 *)(o); - int length = *(u8 *)(o + 1); - if (length == 0) + int type = o[0]; + int length = o[1]; + if (length < 2) { - log(4, 0, 0, 0, " Option length is 0...\n"); + LOG(4, 0, 0, " Option length is %d...\n", length); break; } if (type == 0) { - log(4, 0, 0, 0, " Option type is 0...\n"); + LOG(4, 0, 0, " Option type is 0...\n"); x -= length; o += length; continue; @@ -236,41 +270,52 @@ void dumplcp(char *p, int l) switch (type) { case 1: // Maximum-Receive-Unit - log(4, 0, 0, 0, " %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2))); + if (length == 4) + LOG(4, 0, 0, " %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2))); + else + LOG(4, 0, 0, " %s odd length %d\n", lcp_types[type], length); break; - case 3: // Authentication-Protocol + case 2: // Async-Control-Character-Map + if (length == 6) { - int proto = ntohs(*(u16 *)(o + 2)); - log(4, 0, 0, 0, " %s %s\n", lcp_types[type], - proto == 0xC223 ? "CHAP" : "PAP"); - break; + u32 asyncmap = ntohl(*(u32 *)(o + 2)); + LOG(4, 0, 0, " %s %x\n", lcp_types[type], asyncmap); } - case 5: // Magic-Number + else + LOG(4, 0, 0, " %s odd length %d\n", lcp_types[type], length); + break; + case 3: // Authentication-Protocol + if (length == 4) { - u32 magicno = ntohl(*(u32 *)(o + 2)); - log(4, 0, 0, 0, " %s %x\n", lcp_types[type], magicno); - break; + 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"); } + else + LOG(4, 0, 0, " %s odd length %d\n", lcp_types[type], length); + break; case 4: // Quality-Protocol { u32 qp = ntohl(*(u32 *)(o + 2)); - log(4, 0, 0, 0, " %s %x\n", lcp_types[type], qp); - break; + LOG(4, 0, 0, " %s %x\n", lcp_types[type], qp); } - case 7: // Protocol-Field-Compression + break; + case 5: // Magic-Number + if (length == 6) { - u32 pfc = ntohl(*(u32 *)(o + 2)); - log(4, 0, 0, 0, " %s %x\n", lcp_types[type], pfc); - break; + u32 magicno = ntohl(*(u32 *)(o + 2)); + LOG(4, 0, 0, " %s %x\n", lcp_types[type], magicno); } + else + LOG(4, 0, 0, " %s odd length %d\n", lcp_types[type], length); + break; + case 7: // Protocol-Field-Compression case 8: // Address-And-Control-Field-Compression - { - u32 afc = ntohl(*(u32 *)(o + 2)); - log(4, 0, 0, 0, " %s %x\n", lcp_types[type], afc); - break; - } + LOG(4, 0, 0, " %s\n", lcp_types[type]); + break; default: - log(2, 0, 0, 0, " Unknown PPP LCP Option type %d\n", type); + LOG(2, 0, 0, " Unknown PPP LCP Option type %d\n", type); break; } x -= length; @@ -279,188 +324,299 @@ void dumplcp(char *p, int l) } // Process LCP messages -void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) +void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l) { u8 b[MAXCONTROL]; u8 *q = NULL; + u32 magicno = 0; + u16 hl; + + CSTAT(call_processlcp); -#ifdef STAT_CALLS - STAT(call_processlcp); -#endif - log_hex(5, "LCP", p, l); + LOG_HEX(5, "LCP", p, l); if (l < 4) { - log(1, session[s].ip, s, t, "Short LCP %d bytes", l); + LOG(1, s, t, "Short LCP %d bytes\n", l); + STAT(tunnel_rx_errors); + return ; + } + + if ((hl = ntohs(*(u16 *) (p + 2))) > l) + { + LOG(1, s, t, "Length mismatch LCP %u/%u\n", hl, l); STAT(tunnel_rx_errors); return ; } + l = hl; + if (*p == ConfigAck) { - log(3, session[s].ip, s, t, "LCP: Discarding ConfigAck\n"); + LOG(3, s, t, "LCP: Discarding ConfigAck\n"); + session[s].flags |= SF_LCP_ACKED; } else if (*p == ConfigReq) { - signed int x = l - 1; - char *o = (p + 1); + int x = l - 4; + u8 *o = (p + 4); + u8 *response = 0; - log(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l); + LOG(3, s, t, "LCP: ConfigReq (%d bytes)...\n", l); + if (config->debug > 3) dumplcp(p, l); while (x > 2) { - int type = *(u8 *)(o); - int length = *(u8 *)(o + 1); - if (length == 0 || type == 0) break; + 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)); 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 = response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP); + if (!q) break; + *q = ConfigNak; + q += 4; + } + + if ((q - b + 11) > sizeof(b)) + { + LOG(2, s, t, "LCP overflow for asyncmap ConfigNak.\n"); + break; + } + + *q++ = type; + *q++ = 6; + memset(q, 0, 4); // asyncmap 0 + q += 4; + *((u16 *) (response + 2)) = htons(q - response); // LCP header length + break; + case 3: // Authentication-Protocol { int proto = ntohs(*(u16 *)(o + 2)); - if (proto == 0xC223) + char proto_name[] = "0x0000"; + if (proto == PPPPAP) + break; + + if (response && *response != ConfigNak) // rej already queued + 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); + + if (!response) { - log(2, session[s].ip, s, t, " Remote end is trying to do CHAP. Rejecting it.\n"); - - if (!q) - { - q = makeppp(b, p, l, t, s, PPPLCP); - *q++ = ConfigNak; - } - memcpy(q, o, length); - *(u16 *)(q += 2) = htons(0xC023); // NAK -> Use PAP instead - q += length; + q = response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP); + if (!q) break; + *q = ConfigNak; + q += 4; } - break; + + if ((q - b + length) > sizeof(b)) + { + LOG(2, s, t, "LCP overflow for %s ConfigNak.\n", proto_name); + break; + } + + memcpy(q, o, length); + *(u16 *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead + q += length; + *((u16 *) (response + 2)) = htons(q - response); } + break; + case 5: // Magic-Number - { -// u32 magicno = ntohl(*(u32 *)(o + 2)); - break; - } + magicno = ntohl(*(u32 *)(o + 2)); + break; + case 4: // Quality-Protocol - { -// u32 qp = ntohl(*(u32 *)(o + 2)); - break; - } case 7: // Protocol-Field-Compression + case 8: // Address-And-Control-Field-Compression + 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 { -// u32 pfc = ntohl(*(u32 *)(o + 2)); - break; + q = response = makeppp(b, sizeof(b), p, 2, t, s, PPPLCP); + if (!q) break; + *q = ConfigRej; + q += 4; } - case 8: // Address-And-Control-Field-Compression + + if ((q - b + length) > sizeof(b)) { -// u32 afc = ntohl(*(u32 *)(o + 2)); + LOG(2, s, t, "LCP overflow for ConfigRej (type=%d).\n", type); break; } - default: - log(2, session[s].ip, s, t, " Unknown PPP LCP Option type %d\n", type); - break; + + memcpy(q, o, length); + q += length; + *((u16 *) (response + 2)) = htons(q - response); // LCP header length } x -= length; o += length; } - if (!q) + if (!response) { // Send back a ConfigAck - log(3, session[s].ip, s, t, "ConfigReq accepted, sending as Ack\n"); - q = makeppp(b, p, l, t, s, PPPLCP); + q = response = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); + if (!q) return; *q = ConfigAck; - tunnelsend(b, l + (q - b), t); - } - else - { - // Already built a ConfigNak... send it - log(3, session[s].ip, s, t, "Sending ConfigNak\n"); - tunnelsend(b, l + (q - b), t); - - log(3, session[s].ip, s, t, "Sending ConfigReq, requesting PAP login\n"); - q = makeppp(b, NULL, 0, t, s, PPPLCP); - *q++ = ConfigReq; - *(u8 *)(q++) = 3; - *(u8 *)(q++) = 4; - *(u16 *)(q += 2) = htons(0xC023); - tunnelsend(b, l + (q - b), t); } + + LOG(3, s, t, "Sending %s\n", ppp_lcp_types[*response]); + tunnelsend(b, l + (q - b), t); + + if (!(session[s].flags & SF_LCP_ACKED)) + initlcp(t, s); } else if (*p == ConfigNak) { - log(1, session[s].ip, s, t, "Remote end sent a ConfigNak. Ignoring\n"); - dumplcp(p, l); + LOG(1, s, t, "Remote end sent a ConfigNak. Ignoring\n"); + if (config->debug > 3) dumplcp(p, l); return ; } else if (*p == TerminateReq) { - *p = TerminateAck; // close - q = makeppp(b, p, l, t, s, PPPLCP); - log(3, session[s].ip, s, t, "LCP: Received TerminateReq. Sending TerminateAck\n"); - sessionshutdown(s, "Remote end closed connection."); + LOG(3, s, t, "LCP: Received TerminateReq. Sending TerminateAck\n"); + *p = TerminateAck; // close + q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); + if (!q) return; tunnelsend(b, l + (q - b), t); // send it + sessionshutdown(s, "Remote end closed connection."); } - else if (*p == TerminateReq) + else if (*p == TerminateAck) { - sessionshutdown(s, "Remote end closed connection."); + sessionshutdown(s, "Connection closed."); } else if (*p == EchoReq) { - *p = EchoReply; // reply + 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, p, l, t, s, PPPLCP); - log(4, session[s].ip, s, t, "LCP: Received EchoReq. Sending EchoReply\n"); + q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); + if (!q) return; 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) + { + *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, session[s].ip, s, t, "Unexpected LCP code %d\n", *p); + LOG(1, s, t, "Unexpected LCP code %d\n", *p); STAT(tunnel_rx_errors); return ; } } +// find a PPP option, returns point to option, or 0 if not found +static u8 *findppp(u8 *b, u8 mtype) +{ + u16 l = ntohs(*(u16 *) (b + 2)); + if (l < 4) + return 0; + b += 4; + l -= 4; + while (l) + { + if (l < b[1] || !b[1]) + return 0; // faulty + if (*b == mtype) + return b; + l -= b[1]; + b += b[1]; + } + return 0; +} + // Process IPCP messages -void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) +void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l) { -#ifdef STAT_CALLS - STAT(call_processipcp); -#endif - log_hex(5, "IPCP", p, l); + u16 hl; + + CSTAT(call_processipcp); + + LOG_HEX(5, "IPCP", p, l); if (l < 5) { - log(1, 0, s, t, "Short IPCP %d bytes", l); + LOG(1, s, t, "Short IPCP %d bytes\n", l); + STAT(tunnel_rx_errors); + return ; + } + + if ((hl = ntohs(*(u16 *) (p + 2))) > l) + { + LOG(1, s, t, "Length mismatch IPCP %u/%u\n", hl, l); STAT(tunnel_rx_errors); return ; } + l = hl; + if (*p == ConfigAck) - { // happy with our IPCP - u8 r = session[s].radius; + { + // happy with our IPCP + u16 r = session[s].radius; if ((!r || radius[r].state == RADIUSIPCP) && !session[s].walled_garden) + { if (!r) r = radiusnew(s); if (r) radiussend(r, RADIUSSTART); // send radius start, having got IPCP at last - return ; // done + } + session[s].flags |= SF_IPCP_ACKED; + + LOG(3, s, t, "IPCP Acked, session is now active\n"); + + // clear LCP_ACKED/CCP_ACKED flag for possible fast renegotiaion for routers + session[s].flags &= ~(SF_LCP_ACKED|SF_CCP_ACKED); + + return; } if (*p != ConfigReq) { - log(1, 0, s, t, "Unexpected IPCP code %d\n", *p); - STAT(tunnel_rx_errors); - return ; - } - if (ntohs(*(u16 *) (p + 2)) > l) - { - log(1, 0, s, t, "Length mismatch IPCP %d/%d\n", ntohs(*(u16 *) (p + 2)), l); + LOG(1, s, t, "Unexpected IPCP code %d\n", *p); STAT(tunnel_rx_errors); return ; } + LOG(4, s, t, "IPCP ConfigReq received\n"); + if (!session[s].ip) { - log(3, 0, s, t, "Waiting on radius reply\n"); - return ; // have to wait on RADIUS eply + LOG(3, s, t, "Waiting on radius reply\n"); + return; // have to wait on RADIUS reply } // form a config reply quoting the IP in the session { @@ -477,50 +633,57 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) q += q[1]; } if (q < i) - { // reject + { + // reject u16 n = 4; i = p + l; - q = makeppp(b, p, l, t, s, PPPIPCP); + if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP))) + return; + *q = ConfigRej; p += 4; while (p < i && p[1]) { if (*p != 0x81 && *p != 0x83 && *p != 3) { - log(2, 0, s, t, "IPCP reject %d\n", *p); + LOG(2, s, t, "IPCP reject %d\n", *p); memcpy(q + n, p, p[1]); n += p[1]; } p += p[1]; } *(u16 *) (q + 2) = htons(n); + LOG(4, s, t, "Sending ConfigRej\n"); tunnelsend(b, n + (q - b), t); // send it } else { + LOG(4, s, t, "Sending ConfigAck\n"); *p = ConfigAck; - i = findppp(p, 0x81); // Primary DNS address - if (i) + 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(htonl(session[s].dns1), 0)); } } - i = findppp(p, 0x83); // Secondary DNS address (TBA, is it) - if (i) + 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(htonl(session[s].dns2), 0)); } } - i = findppp(p, 3); // IP address + i = findppp(p, 3); // IP address if (!i || i[1] != 6) { - log(1, 0, s, t, "No IP in IPCP request\n"); + LOG(1, s, t, "No IP in IPCP request\n"); STAT(tunnel_rx_errors); return ; } @@ -528,118 +691,201 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) { *(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)); } - q = makeppp(b, p, l, t, s, PPPIPCP); + if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP))) + return; + tunnelsend(b, l + (q - b), t); // send it } } } // process IP packet received -void processipin(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) { -#ifdef STAT_CALLS - STAT(call_processipin); -#endif - log_hex(5, "IP", p, l); + ipt ip; + + CSTAT(call_processipin); + + LOG_HEX(5, "IP", p, l); + + ip = ntohl(*(u32 *)(p + 12)); if (l > MAXETHER) { - log(1, *(u32 *)(p + 12), s, t, "IP packet too long %d\n", l); + LOG(1, s, t, "IP packet too long %d\n", l); STAT(tunnel_rx_errors); return ; } - session[s].cin += l; - session[s].total_cin += l; - session[s].pin++; - eth_tx += l; + // no spoof (do sessionbyip to handled statically routed subnets) + if (ip != session[s].ip && sessionbyip(htonl(ip)) != s) + { + LOG(5, s, t, "Dropping packet with spoofed IP %s\n", fmtaddr(htonl(ip), 0)); + return; + } + + // run access-list if any + if (session[s].filter_in && !ip_filter(p, l, session[s].filter_in - 1)) + return; // Add on the tun header p -= 4; *(u32 *)p = htonl(0x00000800); l += 4; - // Plugin hook - { - struct param_packet_rx packet = { &tunnel[t], &session[s], p, l }; - run_plugins(PLUGIN_PACKET_TX, &packet); + 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. + return; + } + + if (session[s].tbf_in && config->cluster_iam_master) { // Are we throttled and a master?? actually handle the throttled packets. + tbf_queue_packet(session[s].tbf_in, p, l); + return; } // send to ethernet - if (write(tapfd, p, l) < 0) + if (tun_write(p, l) < 0) { - STAT(tap_tx_errors); - log(0, 0, s, t, "Error writing %d bytes to TAP device: %s (tapfd=%d, p=%p)\n", - l, strerror(errno), tapfd, p); + 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; } - if (session[s].snoop) + if (session[s].snoop_ip && session[s].snoop_port) { - // Snooping this session, send it to ASIO - snoop_send_packet(p, l); + // Snooping this session + snoop_send_packet(p + 4, l - 4, session[s].snoop_ip, session[s].snoop_port); } - STAT(tap_tx_packets); - INC_STAT(tap_tx_bytes, l); + + session[s].cin += l - 4; + session[s].total_cin += l - 4; + sess_count[s].cin += l - 4; + + session[s].pin++; + eth_tx += l - 4; + + STAT(tun_tx_packets); + INC_STAT(tun_tx_bytes, l - 4); } -// Process LCP messages -void processccp(tunnelidt t, sessionidt s, u8 * p, u16 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) { -#ifdef STAT_CALLS - STAT(call_processccp); -#endif - log_hex(5, "CCP", p, l); - if (l < 2 || (*p != ConfigReq && *p != TerminateReq)) + LOG_HEX(5, "IP in throttled", buf, len); + + if (write(tunfd, buf, len) < 0) { - log(1, 0, s, t, "Unexpecetd CCP request code %d\n", *p); - STAT(tunnel_rx_errors); - return ; + STAT(tun_tx_errors); + LOG(0, 0, 0, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n", + len, strerror(errno), tunfd, buf); + + return; } - // reject + + if (session[s].snoop_ip && session[s].snoop_port) { - u8 b[MAXCONTROL]; - u8 *q; - if (*p == ConfigReq) + // Snooping this session + snoop_send_packet(buf + 4, len - 4, 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; + + session[s].pin++; + eth_tx += len - 4; + + STAT(tun_tx_packets); + INC_STAT(tun_tx_bytes, len - 4); +} + + +// Process CCP messages +void processccp(tunnelidt t, sessionidt s, u8 *p, u16 l) +{ + u8 b[MAXCONTROL]; + u8 *q; + + CSTAT(call_processccp); + + LOG_HEX(5, "CCP", p, l); + switch (l > 1 ? *p : 0) + { + case ConfigAck: + session[s].flags |= SF_CCP_ACKED; + return; + + case ConfigReq: + if (l < 6) // accept no compression { - if (l < 6) - { - *p = ConfigAck; // accept no compression - } - else - { - *p = ConfigRej; // reject - } + *p = ConfigAck; + break; } + + // compression requested--reject + *p = ConfigRej; + + // send CCP request for no compression for our end if not negotiated + if (!(session[s].flags & SF_CCP_ACKED)) + initccp(t, s); + + break; + + case TerminateReq: + *p = TerminateAck; + break; + + default: + if (l > 1) + LOG(1, s, t, "Unexpected CCP request code %d\n", *p); else - *p = TerminateAck; // close - q = makeppp(b, p, l, t, s, PPPCCP); - tunnelsend(b, l + (q - b), t); // send it + LOG(1, s, t, "Short CCP packet\n"); + + STAT(tunnel_rx_errors); + return; } + + if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP))) + return; + + tunnelsend(b, l + (q - b), t); // send it } // send a CHAP PP packet void sendchap(tunnelidt t, sessionidt s) { u8 b[MAXCONTROL]; - u8 r = session[s].radius; + u16 r = session[s].radius; u8 *q; -#ifdef STAT_CALLS - STAT(call_sendchap); -#endif + + CSTAT(call_sendchap); + if (!r) { - log(1, 0, s, t, "No RADIUS to send challenge\n"); + LOG(1, s, t, "No RADIUS to send challenge\n"); STAT(tunnel_tx_errors); return ; } - log(1, 0, s, t, "Send CHAP challenge\n"); - { // new challenge + 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].chap = 1; // CHAP not PAP radius[r].id++; if (radius[r].state != RADIUSCHAP) radius[r].try = 0; @@ -651,12 +897,14 @@ void sendchap(tunnelidt t, sessionidt s) STAT(tunnel_tx_errors); return ; } - q = makeppp(b, 0, 0, t, s, PPPCHAP); - *q = 1; // challenhe - q[1] = radius[r].id; // ID - q[4] = 16; // length - memcpy(q + 5, radius[r].auth, 16); // challenge - strcpy(q + 21, hostname); // our name + q = makeppp(b, sizeof(b), 0, 0, t, s, PPPCHAP); + if (!q) return; + + *q = 1; // challenge + q[1] = radius[r].id; // ID + q[4] = 16; // length + memcpy(q + 5, radius[r].auth, 16); // challenge + strcpy(q + 21, hostname); // our name *(u16 *) (q + 2) = htons(strlen(hostname) + 21); // length tunnelsend(b, strlen(hostname) + 21 + (q - b), t); // send it } @@ -664,62 +912,83 @@ void sendchap(tunnelidt t, sessionidt s) // 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, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype) +u8 *makeppp(u8 *b, int size, u8 *p, int l, tunnelidt t, sessionidt s, u16 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; + } + *(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 b += 6; - if (mtype != PPPLCP && !(session[s].flags & SESSIONACFC)) + if (mtype == PPPLCP || !(session[s].l2tp_flags & SESSIONACFC)) { *(u16 *) b = htons(0xFF03); // HDLC header b += 2; } - if (mtype < 0x100 && session[s].flags & SESSIONPFC) + if (mtype < 0x100 && session[s].l2tp_flags & SESSIONPFC) *b++ = mtype; else { *(u16 *) b = htons(mtype); b += 2; } + + 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; + } + if (p && l) memcpy(b, p, l); + return b; } -// find a PPP option, returns point to option, or 0 if not found -u8 *findppp(u8 * b, u8 mtype) +// Send initial LCP ConfigReq for PAP, set magic no. +void initlcp(tunnelidt t, sessionidt s) { - u16 l = ntohs(*(u16 *) (b + 2)); - if (l < 4) - return 0; - b += 4; - l -= 4; - while (l) - { - if (l < b[1] || !b[1]) - return 0; // faulty - if (*b == mtype) - return b; - l -= b[1]; - b += b[1]; - } - return 0; + char b[500], *q; + + if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, 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); } -// Send initial LCP ConfigReq -void initlcp(tunnelidt t, sessionidt s) +// Send CCP request for no compression +static void initccp(tunnelidt t, sessionidt s) { - char b[500] = {0}, *q; + char b[500], *q; - q = makeppp(b, NULL, 0, t, s, PPPLCP); - log(4, 0, s, t, "Sending LCP ConfigReq for PAP\n"); + if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP))) + return; + + LOG(4, s, t, "Sending CCP ConfigReq for no compression\n"); *q = ConfigReq; *(u8 *)(q + 1) = (time_now % 255) + 1; // ID - *(u16 *)(q + 2) = htons(8); // Length - *(u8 *)(q + 4) = 3; - *(u8 *)(q + 5) = 4; - *(u16 *)(q + 6) = htons(0xC023); // PAP - tunnelsend(b, 12 + 8, t); -} + *(u16 *)(q + 2) = htons(4); // Length + LOG_HEX(5, "PPPCCP", q, 4); + tunnelsend(b, (q - b) + 4 , t); +}