X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/1af4c16721440b4b92c63ab0977ae8e6814fcf93..59aaa188eb91d3fccdb7eca74a9e53fbef92e9e3:/ppp.c diff --git a/ppp.c b/ppp.c index e1edba1..cf34bc0 100644 --- a/ppp.c +++ b/ppp.c @@ -1,5 +1,6 @@ // L2TPNS PPP Stuff -// $Id: ppp.c,v 1.4 2004/05/24 04:26:01 fred_nerk Exp $ + +char const *cvs_id_ppp = "$Id: ppp.c,v 1.17 2004/10/29 04:01:53 bodea Exp $"; #include #include @@ -10,30 +11,33 @@ #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; +void sendccp(tunnelidt t, sessionidt s); + // Process PAP messages void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) { char user[129]; char pass[129]; -#ifdef STAT_CALLS - STAT(call_processpap); -#endif + + CSTAT(call_processpap); + log_hex(5, "PAP", p, l); if (l < 4) { - log(1, 0, s, t, "Short PAP %u bytes", l); + log(1, 0, s, t, "Short PAP %u bytes\n", l); STAT(tunnel_rx_errors); return ; } @@ -66,27 +70,33 @@ void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l) // 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) { // Failed to make ppp header! + log(1,0,0,0, "Failed to make PPP header in process pap!\n"); + 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, 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); + session[s].flags &= ~SF_IPCP_ACKED; } else { - log(1, 0, s, t, "No radius session available to authenticate session...\n"); + log(1, 0, 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"); tunnelsend(b, 5 + (p - b), t); // send it } else - { // set up RADIUS request + { + // set up RADIUS request u16 r = session[s].radius; // Run PRE_AUTH plugins @@ -118,14 +128,17 @@ void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l) u16 r; u16 len; -#ifdef STAT_CALLS - STAT(call_processchap); -#endif + + CSTAT(call_processchap); + log_hex(5, "CHAP", p, l); r = session[s].radius; if (!r) { log(1, 0, s, t, "Unexpected CHAP message\n"); + +// FIXME: Need to drop the session here. + STAT(tunnel_rx_errors); return; } @@ -204,26 +217,27 @@ char *ppp_lcp_types[] = { "EchoReq", "EchoReply", "DiscardRequest", + "IdentRequest", }; -void dumplcp(char *p, int l) +void dumplcp(u8 *p, int l) { - signed int x = l - 3; - char *o = (p + 3); + signed 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, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_types[(int)*p], ntohs( ((u16 *) p)[1]) ); log(4, 0, 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, 0, " Option length is %d...\n", length); break; } if (type == 0) @@ -236,19 +250,22 @@ 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, 0, " %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2))); + else + log(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length); break; case 3: // Authentication-Protocol { - int proto = ntohs(*(u16 *)(o + 2)); - log(4, 0, 0, 0, " %s %s\n", lcp_types[type], - proto == 0xC223 ? "CHAP" : "PAP"); - break; - } - case 5: // Magic-Number - { - u32 magicno = ntohl(*(u32 *)(o + 2)); - log(4, 0, 0, 0, " %s %x\n", lcp_types[type], magicno); + if (length == 4) + { + int proto = ntohs(*(u16 *)(o + 2)); + log(4, 0, 0, 0, " %s 0x%x (%s)\n", lcp_types[type], proto, + proto == 0xC223 ? "CHAP" : + proto == 0xC023 ? "PAP" : "UNKNOWN"); + } + else + log(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length); break; } case 4: // Quality-Protocol @@ -257,16 +274,25 @@ void dumplcp(char *p, int l) log(4, 0, 0, 0, " %s %x\n", lcp_types[type], qp); break; } + case 5: // Magic-Number + { + if (length == 6) + { + u32 magicno = ntohl(*(u32 *)(o + 2)); + log(4, 0, 0, 0, " %s %x\n", lcp_types[type], magicno); + } + else + log(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length); + break; + } case 7: // Protocol-Field-Compression { - u32 pfc = ntohl(*(u32 *)(o + 2)); - log(4, 0, 0, 0, " %s %x\n", lcp_types[type], pfc); + log(4, 0, 0, 0, " %s\n", lcp_types[type]); break; } 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); + log(4, 0, 0, 0, " %s\n", lcp_types[type]); break; } default: @@ -283,38 +309,46 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) { u8 b[MAXCONTROL]; u8 *q = NULL; + u32 magicno = 0; + + + CSTAT(call_processlcp); -#ifdef STAT_CALLS - STAT(call_processlcp); -#endif log_hex(5, "LCP", p, l); if (l < 4) { - log(1, session[s].ip, s, t, "Short LCP %d bytes", l); + log(1, session[s].ip, s, t, "Short LCP %d bytes\n", l); STAT(tunnel_rx_errors); return ; } if (*p == ConfigAck) { log(3, session[s].ip, s, t, "LCP: Discarding ConfigAck\n"); + session[s].flags |= SESSIONLCPACK; } else if (*p == ConfigReq) { - signed int x = l - 1; - char *o = (p + 1); + l = ntohs(*(u16 *)(p + 2)); + signed int x = l - 4; + u8 *o = (p + 4); log(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l); + dumplcp(p, l); while (x > 2) { - int type = *(u8 *)(o); - int length = *(u8 *)(o + 1); + int type = o[0]; + int length = o[1]; if (length == 0 || type == 0) break; switch (type) { case 1: // Maximum-Receive-Unit session[s].mru = ntohs(*(u16 *)(o + 2)); break; + case 2: // asyncmap + log_hex(2, "PPP LCP Packet", p, l); + log(2, 0, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_types[(int)*p], ntohs( ((u16 *) p)[1]) ); + break; case 3: // Authentication-Protocol { int proto = ntohs(*(u16 *)(o + 2)); @@ -324,7 +358,11 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) if (!q) { - q = makeppp(b, p, l, t, s, PPPLCP); + q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); + if (!q) { + log(2, session[s].ip, s, t, " Failed to send packet.\n"); + break; + } *q++ = ConfigNak; } memcpy(q, o, length); @@ -335,27 +373,36 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) } case 5: // Magic-Number { -// u32 magicno = ntohl(*(u32 *)(o + 2)); + magicno = ntohl(*(u32 *)(o + 2)); break; } case 4: // Quality-Protocol - { -// u32 qp = ntohl(*(u32 *)(o + 2)); - break; - } case 7: // Protocol-Field-Compression - { -// u32 pfc = ntohl(*(u32 *)(o + 2)); - break; - } case 8: // Address-And-Control-Field-Compression - { -// u32 afc = ntohl(*(u32 *)(o + 2)); break; + case 13: // CallBack option for LCP extention of win2000/routers L2TP client + case 17: + case 18: + { + // Reject LCP CallBack + log(2, session[s].ip, s, t, " PPP LCP Option type %d, len=%d\n", type, length); + memcpy(p + 4, o, length); + *(u16 *)(p + 2) = htons(length + 4); + *p = ConfigRej; + q = makeppp(b,sizeof(b), p, length + 4, t, s, PPPLCP); + tunnelsend(b, 12 + length + 4, t); + return; } + default: + // Reject Unknown LCP Option to stop to send it again log(2, session[s].ip, s, t, " Unknown PPP LCP Option type %d\n", type); - break; + memcpy(p + 4, o, length); + *(u16 *)(p + 2) = htons(length + 4); + *p = ConfigRej; + q = makeppp(b,sizeof(b), p, length + 4, t, s, PPPLCP); + tunnelsend(b, 12 + length + 4, t); + return; } x -= length; o += length; @@ -365,7 +412,14 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) { // 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); + // for win2k L2TP clients and LCP renegotiation of alive session + if (magicno || l == 4 || (session[s].mru && l == 8)) initlcp(t, s); + q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); + if (!q) + { + log(3, session[s].ip, s, t, " failed to create packet.\n"); + return; + } *q = ConfigAck; tunnelsend(b, l + (q - b), t); } @@ -374,15 +428,10 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) // 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); } + + if (!(session[s].flags & SESSIONLCPACK)) + initlcp(t, s); } else if (*p == ConfigNak) { @@ -392,21 +441,29 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) } else if (*p == TerminateReq) { - *p = TerminateAck; // close - q = makeppp(b, p, l, t, s, PPPLCP); + *p = TerminateAck; // close + q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); + if (!q) { + log(3, session[s].ip, s, t, "Failed to create PPP packet in processlcp.\n"); + return; + } log(3, session[s].ip, s, t, "LCP: Received TerminateReq. Sending TerminateAck\n"); sessionshutdown(s, "Remote end closed connection."); tunnelsend(b, l + (q - b), t); // send it } - 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 + *p = EchoReply; // reply *(u32 *) (p + 4) = htonl(session[s].magic); // our magic number - q = makeppp(b, p, l, t, s, PPPLCP); + q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP); + if (!q) { + log(3, session[s].ip, s, t, " failed to send EchoReply.\n"); + return; + } log(5, session[s].ip, s, t, "LCP: Received EchoReq. Sending EchoReply\n"); tunnelsend(b, l + (q - b), t); // send it } @@ -414,6 +471,23 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) { // Ignore it, last_packet time is set earlier than this. } + else if (*p == IdentRequest) + { + *p = CodeRej; + if (l > MAXCONTROL) + { + log(1, 0, 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) + { + log(3, session[s].ip, s, t, "Failed to create IdentRej.\n"); + 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); @@ -425,25 +499,31 @@ void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l) // Process IPCP messages void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) { -#ifdef STAT_CALLS - STAT(call_processipcp); -#endif + + CSTAT(call_processipcp); + log_hex(5, "IPCP", p, l); if (l < 5) { - log(1, 0, s, t, "Short IPCP %d bytes", l); + log(1, 0, s, t, "Short IPCP %d bytes\n", l); STAT(tunnel_rx_errors); return ; } if (*p == ConfigAck) - { // happy with our IPCP + { + // 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, session[s].ip, s, t, "IPCP Acked, session is now active\n"); + return; } if (*p != ConfigReq) { @@ -451,6 +531,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) STAT(tunnel_rx_errors); return ; } + log(4, session[s].ip, s, t, "IPCP ConfigReq received\n"); if (ntohs(*(u16 *) (p + 2)) > l) { log(1, 0, s, t, "Length mismatch IPCP %d/%d\n", ntohs(*(u16 *) (p + 2)), l); @@ -460,7 +541,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) if (!session[s].ip) { log(3, 0, s, t, "Waiting on radius reply\n"); - return ; // have to wait on RADIUS eply + return; // have to wait on RADIUS reply } // form a config reply quoting the IP in the session { @@ -468,6 +549,7 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) u8 *i, *q; + l = ntohs(*(u16 *) (p + 2)); // We must use length from IPCP len field q = p + 4; i = p + l; while (q < i && q[1]) @@ -477,10 +559,15 @@ 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))) + { + log(2, 0, s, t, "Failed to send IPCP ConfigRej\n"); + return; + } *q = ConfigRej; p += 4; while (p < i && p[1]) @@ -494,30 +581,32 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) p += p[1]; } *(u16 *) (q + 2) = htons(n); + log(4, session[s].ip, s, t, "Sending ConfigRej\n"); tunnelsend(b, n + (q - b), t); // send it } else { + log(4, session[s].ip, 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, session[s].ip, s, t, " DNS1 = %s\n", inet_toa(session[s].dns1)); } } - 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, session[s].ip, s, t, " DNS2 = %s\n", inet_toa(session[s].dns1)); } } - 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"); @@ -528,65 +617,121 @@ void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l) { *(u32 *) (i + 2) = htonl(session[s].ip); *p = ConfigNak; + log(4, session[s].ip, s, t, " No, a ConfigNak, client is requesting IP - sending %s\n", + inet_toa(htonl(session[s].ip))); + } + if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP))) + { + log(2, 0, s, t, " Failed to send IPCP packet.\n"); + return; } - q = makeppp(b, p, l, t, s, PPPIPCP); tunnelsend(b, l + (q - b), t); // send it } } } // process IP packet received +// +// 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 + 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, ip, 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, ip, s, t, "Dropping packet with spoofed IP %s\n", inet_toa(htonl(ip))); + return; + } // Add on the tun header p -= 4; *(u32 *)p = htonl(0x00000800); l += 4; + 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; + } + + session[s].cin += l - 4; + session[s].total_cin += l - 4; + sess_count[s].cin += l - 4; + + session[s].pin++; + eth_tx += l - 4; + + if (session[s].snoop_ip && session[s].snoop_port) + { + // Snooping this session + snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port); + } + STAT(tun_tx_packets); + INC_STAT(tun_tx_bytes, l); + + 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, 0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n", + l, strerror(errno), tunfd, p); } - if (session[s].snoop) +} + +// +// Helper routine for the TBF filters. +// Used to send queued data in from the user. +// +void send_ipin(sessionidt s, u8 *buf, int len) +{ + log_hex(5, "IP in throttled", buf, len); + if (write(tunfd, buf, len) < 0) { - // Snooping this session, send it to ASIO - snoop_send_packet(p, l); + STAT(tun_tx_errors); + log(0, 0, 0, 0, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n", + len, strerror(errno), tunfd, buf); } - STAT(tap_tx_packets); - INC_STAT(tap_tx_bytes, l); + + // 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; } + // Process LCP messages void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l) { -#ifdef STAT_CALLS - STAT(call_processccp); -#endif + + CSTAT(call_processccp); + log_hex(5, "CCP", p, l); if (l < 2 || (*p != ConfigReq && *p != TerminateReq)) { - log(1, 0, s, t, "Unexpecetd CCP request code %d\n", *p); + log(1, 0, s, t, "Unexpected CCP request code %d\n", *p); STAT(tunnel_rx_errors); return ; } @@ -602,12 +747,17 @@ void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l) } else { - *p = ConfigRej; // reject + *p = ConfigRej; // reject + sendccp(t, s); } } else - *p = TerminateAck; // close - q = makeppp(b, p, l, t, s, PPPCCP); + *p = TerminateAck; // close + if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP))) + { + log(1,0,0,0, "Failed to send CCP packet.\n"); + return; + } tunnelsend(b, l + (q - b), t); // send it } } @@ -618,9 +768,9 @@ void sendchap(tunnelidt t, sessionidt s) u8 b[MAXCONTROL]; 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"); @@ -628,12 +778,13 @@ void sendchap(tunnelidt t, sessionidt s) return ; } log(1, 0, s, t, "Send CHAP challenge\n"); - { // new challenge + { + // 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; @@ -645,12 +796,16 @@ 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) { + log(1, 0, s, t, "failed to send CHAP challenge.\n"); + 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 } @@ -658,24 +813,32 @@ 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) + return NULL; // Need more space than this!! + *(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) { + log(3,0,0,0, "Would have overflowed the buffer in makeppp: size %d, len %d.\n", size, l); + return NULL; // Run out of room to hold the packet! + } if (p && l) memcpy(b, p, l); return b; @@ -692,7 +855,7 @@ u8 *findppp(u8 * b, u8 mtype) while (l) { if (l < b[1] || !b[1]) - return 0; // faulty + return 0; // faulty if (*b == mtype) return b; l -= b[1]; @@ -706,14 +869,34 @@ void initlcp(tunnelidt t, sessionidt s) { char b[500] = {0}, *q; - q = makeppp(b, NULL, 0, t, s, PPPLCP); + q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP); + if (!q) { + log(1, 0, s, t, "Failed to send LCP ConfigReq.\n"); + return; + } log(4, 0, s, t, "Sending LCP ConfigReq for PAP\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(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(0xC023); // PAP + tunnelsend(b, 12 + 14, t); +} + +// Send CCP reply +void sendccp(tunnelidt t, sessionidt s) +{ + char *q, b[500] = {0}; + + q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP); + *q = ConfigReq; + *(u8 *)(q + 1) = (time_now % 255) + 1; // ID + *(u16 *)(q + 2) = htons(4); // Length + log_hex(5, "PPPCCP", q, 4); + tunnelsend(b, (q - b) + 4 , t); }