X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/bb63cb999417e2fea8e70e498b8f8eb97a0edd80..02587abe650caf488727d7674e088df8a3ffd159:/l2tpns.c diff --git a/l2tpns.c b/l2tpns.c index e6d2ba4..10ab3a5 100644 --- a/l2tpns.c +++ b/l2tpns.c @@ -4,7 +4,7 @@ // Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced // vim: sw=8 ts=8 -char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.76 2005/01/10 07:17:37 bodea Exp $"; +char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.89 2005/04/01 06:39:00 bodea Exp $"; #include #include @@ -19,6 +19,7 @@ char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.76 2005/01/10 07:17:37 bodea Exp #include #include #include +#include #include #include #include @@ -62,9 +63,11 @@ int clifd = -1; // Socket listening for CLI connections. int snoopfd = -1; // UDP file handle for sending out intercept data int *radfds = NULL; // RADIUS requests file handles int ifrfd = -1; // File descriptor for routing, etc +int ifr6fd = -1; // File descriptor for IPv6 routing, etc static int rand_fd = -1; // Random data source time_t basetime = 0; // base clock char hostname[1000] = ""; // us. +static int tunidx; // ifr_ifindex of tun device static uint32_t sessionid = 0; // session id for radius accounting static int syslog_log = 0; // are we logging to syslog static FILE *log_stream = NULL; // file handle for direct logging (i.e. direct into file, not via syslog). @@ -75,6 +78,10 @@ struct cli_session_actions *cli_session_actions = NULL; // Pending session chang struct cli_tunnel_actions *cli_tunnel_actions = NULL; // Pending tunnel changes required by CLI static void *ip_hash[256]; // Mapping from IP address to session structures. +struct ipv6radix { + int sess; + struct ipv6radix *branch; +} ipv6_hash[256]; // Mapping from IPv6 address to session structures. // Traffic counters. static uint32_t udp_rx = 0, udp_rx_pkt = 0, udp_tx = 0; @@ -99,7 +106,6 @@ config_descriptt config_values[] = { CONFIG("l2tp_secret", l2tpsecret, STRING), CONFIG("primary_dns", default_dns1, IPv4), CONFIG("secondary_dns", default_dns2, IPv4), - CONFIG("save_state", save_state, BOOL), CONFIG("primary_radius", radiusserver[0], IPv4), CONFIG("secondary_radius", radiusserver[1], IPv4), CONFIG("primary_radius_port", radiusport[0], SHORT), @@ -125,6 +131,7 @@ config_descriptt config_values[] = { CONFIG("cluster_interface", cluster_interface, STRING), CONFIG("cluster_hb_interval", cluster_hb_interval, INT), CONFIG("cluster_hb_timeout", cluster_hb_timeout, INT), + CONFIG("ipv6_prefix", ipv6_prefix, IPv6), { NULL, 0, 0, 0 }, }; @@ -151,7 +158,7 @@ static sessionidt shut_acct_n = 0; tunnelt *tunnel = NULL; // Array of tunnel structures. sessiont *session = NULL; // Array of session structures. -sessioncountt *sess_count = NULL; // Array of partial per-session traffic counters. +sessionlocalt *sess_local = NULL; // Array of local per-session counters. radiust *radius = NULL; // Array of radius structures. ippoolt *ip_address_pool = NULL; // Array of dynamic IP addresses. ip_filtert *ip_filters = NULL; // Array of named filters. @@ -163,6 +170,7 @@ struct Tringbuffer *ringbuffer = NULL; static void cache_ipmap(in_addr_t ip, int s); static void uncache_ipmap(in_addr_t ip); +static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s); static void free_ip_address(sessionidt s); static void dump_acct_info(int all); static void sighup_handler(int sig); @@ -170,8 +178,6 @@ static void sigalrm_handler(int sig); static void sigterm_handler(int sig); static void sigquit_handler(int sig); static void sigchild_handler(int sig); -static void read_state(void); -static void dump_state(void); static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response); static void update_config(void); static void read_config_file(void); @@ -181,7 +187,7 @@ static int remove_plugin(char *plugin_name); static void plugins_done(void); static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen); static tunnelidt new_tunnel(void); -static int unhide_avp(uint8_t *avp, tunnelidt t, sessionidt s, uint16_t length); +static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len); // return internal time (10ths since process startup) static clockt now(void) @@ -421,11 +427,61 @@ static void routeset(sessionidt s, in_addr_t ip, in_addr_t mask, in_addr_t gw, i } } +void route6set(sessionidt s, struct in6_addr ip, int prefixlen, int add) +{ + struct in6_rtmsg rt; + char ipv6addr[INET6_ADDRSTRLEN]; + + if (ifr6fd < 0) + { + LOG(0, 0, 0, "Asked to set IPv6 route, but IPv6 not setup.\n"); + return; + } + + memset(&rt, 0, sizeof(rt)); + + memcpy(&rt.rtmsg_dst, &ip, sizeof(struct in6_addr)); + rt.rtmsg_dst_len = prefixlen; + rt.rtmsg_metric = 1; + rt.rtmsg_flags = RTF_UP; + rt.rtmsg_ifindex = tunidx; + + LOG(1, 0, 0, "Route %s %s/%d\n", + add ? "add" : "del", + inet_ntop(AF_INET6, &ip, ipv6addr, INET6_ADDRSTRLEN), + prefixlen); + + if (ioctl(ifr6fd, add ? SIOCADDRT : SIOCDELRT, (void *) &rt) < 0) + LOG(0, 0, 0, "route6set() error in ioctl: %s\n", + strerror(errno)); + + // FIXME: need to add BGP routing (RFC2858) + + if (s) + { + if (!add) // Are we deleting a route? + s = 0; // Caching the session as '0' is the same as uncaching. + + cache_ipv6map(ip, prefixlen, s); + } + + return; +} + +// defined in linux/ipv6.h, but tricky to include from user-space +// TODO: move routing to use netlink rather than ioctl +struct in6_ifreq { + struct in6_addr ifr6_addr; + __u32 ifr6_prefixlen; + unsigned int ifr6_ifindex; +}; + // // Set up TUN interface static void inittun(void) { struct ifreq ifr; + struct in6_ifreq ifr6; struct sockaddr_in sin = {0}; memset(&ifr, 0, sizeof(ifr)); ifr.ifr_flags = IFF_TUN; @@ -471,6 +527,42 @@ static void inittun(void) LOG(0, 0, 0, "Error setting tun flags: %s\n", strerror(errno)); exit(1); } + if (ioctl(ifrfd, SIOCGIFINDEX, (void *) &ifr) < 0) + { + LOG(0, 0, 0, "Error getting tun ifindex: %s\n", strerror(errno)); + exit(1); + } + tunidx = ifr.ifr_ifindex; + + // Only setup IPv6 on the tun device if we have a configured prefix + if (config->ipv6_prefix.s6_addr[0] > 0) { + ifr6fd = socket(PF_INET6, SOCK_DGRAM, 0); + + // Link local address is FE80::1 + memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr)); + ifr6.ifr6_addr.s6_addr[0] = 0xFE; + ifr6.ifr6_addr.s6_addr[1] = 0x80; + ifr6.ifr6_addr.s6_addr[15] = 1; + ifr6.ifr6_prefixlen = 64; + ifr6.ifr6_ifindex = ifr.ifr_ifindex; + if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0) + { + LOG(0, 0, 0, "Error setting tun IPv6 link local address:" + " %s\n", strerror(errno)); + } + + // Global address is prefix::1 + memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr)); + ifr6.ifr6_addr = config->ipv6_prefix; + ifr6.ifr6_addr.s6_addr[15] = 1; + ifr6.ifr6_prefixlen = 64; + ifr6.ifr6_ifindex = ifr.ifr_ifindex; + if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0) + { + LOG(0, 0, 0, "Error setting tun IPv6 global address: %s\n", + strerror(errno)); + } + } } // set up UDP port @@ -537,17 +629,62 @@ static int lookup_ipmap(in_addr_t ip) return (int) (intptr_t) d[(size_t) *a]; } +static int lookup_ipv6map(struct in6_addr ip) +{ + struct ipv6radix *curnode; + int i; + int s; + char ipv6addr[INET6_ADDRSTRLEN]; + + curnode = &ipv6_hash[ip.s6_addr[0]]; + i = 1; + s = curnode->sess; + + while (s == 0 && i < 15 && curnode->branch != NULL) + { + curnode = &curnode->branch[ip.s6_addr[i]]; + s = curnode->sess; + i++; + } + + LOG(4, s, session[s].tunnel, "Looking up address %s and got %d\n", + inet_ntop(AF_INET6, &ip, ipv6addr, + INET6_ADDRSTRLEN), + s); + + return s; +} + sessionidt sessionbyip(in_addr_t ip) { int s = lookup_ipmap(ip); CSTAT(sessionbyip); - if (s > 0 && s < MAXSESSION && session[s].tunnel) + if (s > 0 && s < MAXSESSION && session[s].opened) return (sessionidt) s; return 0; } +sessionidt sessionbyipv6(struct in6_addr ip) +{ + int s; + CSTAT(sessionbyipv6); + + if (!memcmp(&config->ipv6_prefix, &ip, 8) || + (ip.s6_addr[0] == 0xFE && ip.s6_addr[1] == 0x80 && + (ip.s6_addr16[1] == ip.s6_addr16[2] == ip.s6_addr16[3] == 0))) { + s = lookup_ipmap(*(in_addr_t *) &ip.s6_addr[8]); + } else { + s = lookup_ipv6map(ip); + } + + if (s > 0 && s < MAXSESSION && session[s].opened) + return s; + + return 0; +} + // // Take an IP address in HOST byte order and // add it to the sessionid by IP cache. @@ -587,6 +724,42 @@ static void uncache_ipmap(in_addr_t ip) cache_ipmap(ip, 0); // Assign it to the NULL session. } +static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s) +{ + int i; + int bytes; + struct ipv6radix *curnode; + char ipv6addr[INET6_ADDRSTRLEN]; + + curnode = &ipv6_hash[ip.s6_addr[0]]; + + bytes = prefixlen >> 3; + i = 1; + while (i < bytes) { + if (curnode->branch == NULL) + { + if (!(curnode->branch = calloc(256, + sizeof (struct ipv6radix)))) + return; + } + curnode = &curnode->branch[ip.s6_addr[i]]; + i++; + } + + curnode->sess = s; + + if (s > 0) + LOG(4, s, session[s].tunnel, "Caching ip address %s/%d\n", + inet_ntop(AF_INET6, &ip, ipv6addr, + INET6_ADDRSTRLEN), + prefixlen); + else if (s == 0) + LOG(4, 0, 0, "Un-caching ip address %s/%d\n", + inet_ntop(AF_INET6, &ip, ipv6addr, + INET6_ADDRSTRLEN), + prefixlen); +} + // // CLI list to dump current ipcache. // @@ -642,8 +815,11 @@ sessionidt sessionbyuser(char *username) int s; CSTAT(sessionbyuser); - for (s = 1; s < MAXSESSION ; ++s) + for (s = 1; s <= config->cluster_highest_sessionid ; ++s) { + if (!session[s].opened) + continue; + if (session[s].walled_garden) continue; // Skip walled garden users. @@ -685,17 +861,16 @@ void send_garp(in_addr_t ip) sendarp(ifr.ifr_ifindex, mac, ip); } -// Find session by username, 0 for not found static sessiont *sessiontbysessionidt(sessionidt s) { - if (!s || s > MAXSESSION) return NULL; + if (!s || s >= MAXSESSION) return NULL; return &session[s]; } static sessionidt sessionidtbysessiont(sessiont *s) { sessionidt val = s-session; - if (s < session || val > MAXSESSION) return 0; + if (s < session || val >= MAXSESSION) return 0; return val; } @@ -832,7 +1007,7 @@ static void processipout(uint8_t * buf, int len) // DoS prevention: enforce a maximum number of packets per 0.1s for a session if (config->max_packets > 0) { - if (sess_count[s].last_packet_out == TIME) + if (sess_local[s].last_packet_out == TIME) { int max = config->max_packets; @@ -845,24 +1020,26 @@ static void processipout(uint8_t * buf, int len) if (!config->cluster_iam_master && sp->throttle_out && sp->throttle_out < max) max = sp->throttle_out; - if (++sess_count[s].packets_out > max) + if (++sess_local[s].packets_out > max) { - sess_count[s].packets_dropped++; + sess_local[s].packets_dropped++; return; } } else { - if (sess_count[s].packets_dropped) + if (sess_local[s].packets_dropped) { - INC_STAT(tun_rx_dropped, sess_count[s].packets_dropped); - LOG(2, s, t, "Possible DoS attack on %s (%s); dropped %u packets.", - fmtaddr(ip, 0), sp->user, sess_count[s].packets_dropped); + INC_STAT(tun_rx_dropped, sess_local[s].packets_dropped); + LOG(3, s, t, "Dropped %u/%u packets to %s for %suser %s\n", + sess_local[s].packets_dropped, sess_local[s].packets_out, + fmtaddr(ip, 0), sp->throttle_out ? "throttled " : "", + sp->user); } - sess_count[s].last_packet_out = TIME; - sess_count[s].packets_out = 1; - sess_count[s].packets_dropped = 0; + sess_local[s].last_packet_out = TIME; + sess_local[s].packets_out = 1; + sess_local[s].packets_dropped = 0; } } @@ -903,7 +1080,116 @@ static void processipout(uint8_t * buf, int len) sp->total_cout += len; // byte count sp->pout++; udp_tx += len; - sess_count[s].cout += len; // To send to master.. + sess_local[s].cout += len; // To send to master.. +} + +// process outgoing (to tunnel) IPv6 +// +static void processipv6out(uint8_t * buf, int len) +{ + sessionidt s; + sessiont *sp; + tunnelidt t; + in_addr_t ip; + struct in6_addr ip6; + + char *data = buf; // Keep a copy of the originals. + int size = len; + + uint8_t b[MAXETHER + 20]; + + CSTAT(processipv6out); + + if (len < MIN_IP_SIZE) + { + LOG(1, 0, 0, "Short IPv6, %d bytes\n", len); + STAT(tunnel_tx_errors); + return; + } + if (len >= MAXETHER) + { + LOG(1, 0, 0, "Oversize IPv6 packet %d bytes\n", len); + STAT(tunnel_tx_errors); + return; + } + + // Skip the tun header + buf += 4; + len -= 4; + + // Got an IP header now + if (*(uint8_t *)(buf) >> 4 != 6) + { + LOG(1, 0, 0, "IP: Don't understand anything except IPv6\n"); + return; + } + + ip6 = *(struct in6_addr *)(buf+24); + s = sessionbyipv6(ip6); + + if (s == 0) + { + ip = *(uint32_t *)(buf + 32); + s = sessionbyip(ip); + } + + if (s == 0) + { + // Is this a packet for a session that doesn't exist? + static int rate = 0; // Number of ICMP packets we've sent this second. + static int last = 0; // Last time we reset the ICMP packet counter 'rate'. + + if (last != time_now) + { + last = time_now; + rate = 0; + } + + if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second. + { + // FIXME: Should send icmp6 host unreachable + } + return; + } + t = session[s].tunnel; + sp = &session[s]; + + // FIXME: add DoS prevention/filters? + + if (sp->tbf_out) + { + // Are we throttling this session? + if (config->cluster_iam_master) + tbf_queue_packet(sp->tbf_out, data, size); + else + master_throttle_packet(sp->tbf_out, data, size); + return; + } + else if (sp->walled_garden && !config->cluster_iam_master) + { + // We are walled-gardening this + master_garden_packet(s, data, size); + return; + } + + LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len); + + // Add on L2TP header + { + uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIPV6); + if (!p) return; + tunnelsend(b, len + (p-b), t); // send it... + } + + // Snooping this session, send it to intercept box + if (sp->snoop_ip && sp->snoop_port) + snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port); + + sp->cout += len; // byte count + sp->total_cout += len; // byte count + sp->pout++; + udp_tx += len; + sess_local[s].cout += len; // To send to master.. } // @@ -953,7 +1239,7 @@ static void send_ipout(sessionidt s, uint8_t *buf, int len) sp->total_cout += len; // byte count sp->pout++; udp_tx += len; - sess_count[s].cout += len; // To send to master.. + sess_local[s].cout += len; // To send to master.. } // add an AVP (16 bit) @@ -978,7 +1264,7 @@ static void control32(controlt * c, uint16_t avp, uint32_t val, uint8_t m) c->length += 10; } -// add an AVP (32 bit) +// add an AVP (string) static void controls(controlt * c, uint16_t avp, char *val, uint8_t m) { uint16_t l = ((m ? 0x8000 : 0) + strlen(val) + 6); @@ -1073,7 +1359,7 @@ static void controladd(controlt * c, tunnelidt t, sessionidt s) // void throttle_session(sessionidt s, int rate_in, int rate_out) { - if (!session[s].tunnel) + if (!session[s].opened) return; // No-one home. if (!*session[s].user) @@ -1109,9 +1395,9 @@ void throttle_session(sessionidt s, int rate_in, int rate_out) } // add/remove filters from session (-1 = no change) -void filter_session(sessionidt s, int filter_in, int filter_out) +static void filter_session(sessionidt s, int filter_in, int filter_out) { - if (!session[s].tunnel) + if (!session[s].opened) return; // No-one home. if (!*session[s].user) @@ -1147,16 +1433,16 @@ void filter_session(sessionidt s, int filter_in, int filter_out) } // start tidy shutdown of session -void sessionshutdown(sessionidt s, char *reason) +void sessionshutdown(sessionidt s, char *reason, int result, int error) { int walled_garden = session[s].walled_garden; CSTAT(sessionshutdown); - if (!session[s].tunnel) + if (!session[s].opened) { - LOG(3, s, session[s].tunnel, "Called sessionshutdown on a session with no tunnel.\n"); + LOG(3, s, session[s].tunnel, "Called sessionshutdown on an unopened session.\n"); return; // not a live session } @@ -1167,7 +1453,7 @@ void sessionshutdown(sessionidt s, char *reason) run_plugins(PLUGIN_KILL_SESSION, &data); } - if (session[s].opened && !walled_garden && !session[s].die) + if (session[s].ip && !walled_garden && !session[s].die) { // RADIUS Stop message uint16_t r = session[s].radius; @@ -1213,20 +1499,34 @@ void sessionshutdown(sessionidt s, char *reason) } else free_ip_address(s); + + // unroute IPv6, if setup + if (session[s].flags & SF_IPV6_ROUTED) + route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 0); } if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled. throttle_session(s, 0, 0); + if (result) { // Send CDN controlt *c = controlnew(14); // sending CDN - control16(c, 1, 3, 1); // result code (admin reasons - TBA make error, general error, add message + if (error) + { + char buf[4]; + *(uint16_t *) buf = htons(result); + *(uint16_t *) (buf+2) = htons(error); + controlb(c, 1, buf, 4, 1); + } + else + control16(c, 1, result, 1); + control16(c, 14, s, 1); // assigned session (our end) controladd(c, session[s].tunnel, s); // send the message } if (!session[s].die) - session[s].die = now() + 150; // Clean up in 15 seconds + session[s].die = TIME + 150; // Clean up in 15 seconds // update filter refcounts if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--; @@ -1256,7 +1556,7 @@ void sendipcp(tunnelidt t, sessionidt s) if (radius[r].try > 10) { radiusclear(r, s); // Clear radius session. - sessionshutdown(s, "No reply on IPCP"); + sessionshutdown(s, "No reply on IPCP", 3, 0); return; } @@ -1274,16 +1574,49 @@ void sendipcp(tunnelidt t, sessionidt s) tunnelsend(buf, 10 + (q - buf), t); // send it session[s].flags &= ~SF_IPCP_ACKED; // Clear flag. + + // If we have an IPv6 prefix length configured, assume we should + // try to negotiate an IPv6 session as well. Unless we've had a + // (N)ACK for IPV6CP. + if (config->ipv6_prefix.s6_addr[0] > 0 && + !(session[s].flags & SF_IPV6CP_ACKED) && + !(session[s].flags & SF_IPV6_NACKED)) + { + q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPV6CP); + if (!q) return; + + *q = ConfigReq; + q[1] = r << RADIUS_SHIFT; // ID, don't care, we + // only send one type + // of request + *(uint16_t *) (q + 2) = htons(14); + q[4] = 1; + q[5] = 10; + *(uint32_t *) (q + 6) = 0; // We'll be prefix::1 + *(uint32_t *) (q + 10) = 0; + q[13] = 1; + + tunnelsend(buf, 14 + (q - buf), t); // send it + } } // kill a session now -static void sessionkill(sessionidt s, char *reason) +void sessionkill(sessionidt s, char *reason) { CSTAT(sessionkill); - session[s].die = now(); - sessionshutdown(s, reason); // close radius/routes, etc. + if (!session[s].opened) // not alive + return; + + if (session[s].next) + { + LOG(0, s, session[s].tunnel, "Tried to kill a session with next pointer set (%d)\n", session[s].next); + return; + } + + session[s].die = TIME; + sessionshutdown(s, reason, 3, 0); // close radius/routes, etc. if (session[s].radius) radiusclear(session[s].radius, s); // cant send clean accounting data, session is killed @@ -1324,19 +1657,19 @@ static void tunnelkill(tunnelidt t, char *reason) controlfree = c; } // kill sessions - for (s = 1; s < MAXSESSION; s++) + for (s = 1; s <= config->cluster_highest_sessionid ; ++s) if (session[s].tunnel == t) sessionkill(s, reason); // free tunnel tunnelclear(t); LOG(1, 0, t, "Kill tunnel %d: %s\n", t, reason); - cli_tunnel_actions[s].action = 0; + cli_tunnel_actions[t].action = 0; cluster_send_tunnel(t); } // shut down a tunnel cleanly -static void tunnelshutdown(tunnelidt t, char *reason) +static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg) { sessionidt s; @@ -1351,19 +1684,40 @@ static void tunnelshutdown(tunnelidt t, char *reason) LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason); // close session - for (s = 1; s < MAXSESSION; s++) + for (s = 1; s <= config->cluster_highest_sessionid ; ++s) if (session[s].tunnel == t) - sessionshutdown(s, reason); + sessionshutdown(s, reason, 3, 0); tunnel[t].state = TUNNELDIE; - tunnel[t].die = now() + 700; // Clean up in 70 seconds + tunnel[t].die = TIME + 700; // Clean up in 70 seconds cluster_send_tunnel(t); // TBA - should we wait for sessions to stop? - { // Send StopCCN - controlt *c = controlnew(4); // sending StopCCN - control16(c, 1, 1, 1); // result code (admin reasons - TBA make error, general error, add message) - control16(c, 9, t, 1); // assigned tunnel (our end) - controladd(c, t, 0); // send the message + if (result) + { + controlt *c = controlnew(4); // sending StopCCN + if (error) + { + char buf[64]; + int l = 4; + *(uint16_t *) buf = htons(result); + *(uint16_t *) (buf+2) = htons(error); + if (msg) + { + int m = strlen(msg); + if (m + 4 > sizeof(buf)) + m = sizeof(buf) - 4; + + memcpy(buf+4, msg, m); + l += m; + } + + controlb(c, 1, buf, l, 1); + } + else + control16(c, 1, result, 1); + + control16(c, 9, t, 1); // assigned tunnel (our end) + controladd(c, t, 0); // send the message } } @@ -1438,7 +1792,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) { // control uint16_t message = 0xFFFF; // message type uint8_t fatal = 0; - uint8_t mandatorymessage = 0; + uint8_t mandatory = 0; uint8_t chap = 0; // if CHAP being used uint16_t asession = 0; // assigned session uint32_t amagic = 0; // magic number @@ -1454,7 +1808,10 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) return; } - if ((*buf & 0xCA) != 0xC8) + // control messages must have bits 0x80|0x40|0x08 + // (type, length and sequence) set, and bits 0x02|0x01 + // (offset and priority) clear + if ((*buf & 0xCB) != 0xC8) { LOG(1, s, t, "Bad control header %02X\n", *buf); STAT(tunnel_rx_errors); @@ -1564,71 +1921,111 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) } if (l) { // if not a null message + int result = 0; + int error = 0; + char *msg = 0; + // process AVPs - while (l && !(fatal & 0x80)) + while (l && !(fatal & 0x80)) // 0x80 = mandatory AVP { uint16_t n = (ntohs(*(uint16_t *) p) & 0x3FF); uint8_t *b = p; uint8_t flags = *p; uint16_t mtype; - p += n; // next - if (l < n) + if (n > l) { LOG(1, s, t, "Invalid length in AVP\n"); STAT(tunnel_rx_errors); - fatal = flags; return; } + p += n; // next l -= n; + if (flags & 0x3C) // reserved bits, should be clear + { + LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b); + fatal = flags; + result = 2; // general error + error = 3; // reserved field non-zero + msg = 0; + continue; // next + } + b += 2; + if (*(uint16_t *) (b)) + { + LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b))); + fatal = flags; + result = 2; // general error + error = 6; // generic vendor-specific error + msg = "unsupported vendor-specific"; + continue; // next + } + b += 2; + mtype = ntohs(*(uint16_t *) (b)); + b += 2; + n -= 6; + if (flags & 0x40) { + uint16_t orig_len; + // handle hidden AVPs if (!*config->l2tpsecret) { LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n"); fatal = flags; + result = 2; // general error + error = 6; // generic vendor-specific error + msg = "secret not specified"; continue; } if (!session[s].random_vector_length) { LOG(1, s, t, "Hidden AVP requested, but no random vector.\n"); fatal = flags; + result = 2; // general error + error = 6; // generic + msg = "no random vector"; + continue; + } + if (n < 8) + { + LOG(2, s, t, "Short hidden AVP.\n"); + fatal = flags; + result = 2; // general error + error = 2; // length is wrong + msg = 0; continue; } + LOG(4, s, t, "Hidden AVP\n"); + // Unhide the AVP - n = unhide_avp(b, t, s, n); - if (n == 0) + unhide_value(b, n, mtype, session[s].random_vector, session[s].random_vector_length); + + orig_len = ntohs(*(uint16_t *) b); + if (orig_len > n + 2) { + LOG(1, s, t, "Original length %d too long in hidden AVP of length %d; wrong secret?\n", + orig_len, n); + fatal = flags; + result = 2; // general error + error = 2; // length is wrong + msg = 0; continue; } + + b += 2; + n = orig_len; } - if (*b & 0x3C) - { - LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b); - fatal = flags; - continue; // next - } - b += 2; - if (*(uint16_t *) (b)) - { - LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b))); - fatal = flags; - continue; // next - } - b += 2; - mtype = ntohs(*(uint16_t *) (b)); - b += 2; - n -= 6; LOG(4, s, t, " AVP %d (%s) len %d\n", mtype, avp_name(mtype), n); switch (mtype) { case 0: // message type message = ntohs(*(uint16_t *) b); + mandatory = flags & 0x80; LOG(4, s, t, " Message type = %d (%s)\n", *b, l2tp_message_type(message)); - mandatorymessage = flags; break; case 1: // result code { @@ -1663,6 +2060,9 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) { // allow 0.0 and 1.0 LOG(1, s, t, " Bad protocol version %04X\n", version); fatal = flags; + result = 5; // unspported protocol version + error = 0x0100; // supported version + msg = 0; continue; // next } } @@ -1839,14 +2239,20 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) session[s].random_vector_length = n; break; default: - LOG(2, s, t, " Unknown AVP type %d\n", mtype); - fatal = flags; - continue; // next + { + static char e[] = "unknown AVP 0xXXXX"; + LOG(2, s, t, " Unknown AVP type %d\n", mtype); + fatal = flags; + result = 2; // general error + error = 8; // unknown mandatory AVP + sprintf((msg = e) + 14, "%04x", mtype); + continue; // next + } } } // process message if (fatal & 0x80) - tunnelshutdown(t, "Unknown Mandatory AVP"); + tunnelshutdown(t, "Invalid mandatory AVP", result, error, msg); else switch (message) { @@ -1871,8 +2277,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) break; case 4: // StopCCN controlnull(t); // ack - tunnelshutdown(t, "Stopped"); // Shut down cleanly - tunnelkill(t, "Stopped"); // Immediately force everything dead + tunnelshutdown(t, "Stopped", 0, 0, 0); // Shut down cleanly break; case 6: // HELLO controlnull(t); // simply ACK @@ -1890,7 +2295,8 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) if (!sessionfree) { STAT(session_overflow); - tunnelshutdown(t, "No free sessions"); + LOG(1, 0, t, "No free sessions"); + return; } else { @@ -1914,7 +2320,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) c = controlnew(11); // sending ICRP session[s].id = sessionid++; - session[s].opened = time(NULL); + session[s].opened = time_now; session[s].tunnel = t; session[s].far = asession; session[s].last_packet = time_now; @@ -1945,15 +2351,15 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) break; case 14: // CDN controlnull(t); // ack - sessionshutdown(s, "Closed (Received CDN)"); + sessionshutdown(s, "Closed (Received CDN)", 0, 0); break; case 0xFFFF: LOG(1, s, t, "Missing message type\n"); break; default: STAT(tunnel_rx_errors); - if (mandatorymessage & 0x80) - tunnelshutdown(t, "Unknown message"); + if (mandatory) + tunnelshutdown(t, "Unknown message type", 2, 6, "unknown message type"); else LOG(1, s, t, "Unknown message type %d\n", message); break; @@ -1994,7 +2400,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) l -= 2; } - if (s && !session[s].tunnel) // Is something wrong?? + if (s && !session[s].opened) // Is something wrong?? { if (!config->cluster_iam_master) { @@ -2004,9 +2410,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) } - LOG(1, s, t, "UDP packet contains session %d but no session[%d].tunnel " - "exists (LAC said tunnel = %d). Dropping packet.\n", s, s, t); - + LOG(1, s, t, "UDP packet contains session which is not opened. Dropping packet.\n"); STAT(tunnel_rx_errors); return; } @@ -2035,6 +2439,19 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; } processipcp(t, s, p, l); } + else if (prot == PPPIPV6CP) + { + if (config->ipv6_prefix.s6_addr[0] > 0) + { + session[s].last_packet = time_now; + if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; } + processipv6cp(t, s, p, l); + } + else + { + LOG(1, s, t, "IPv6 not configured; ignoring IPv6CP\n"); + } + } else if (prot == PPPCCP) { session[s].last_packet = time_now; @@ -2058,6 +2475,28 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr) processipin(t, s, p, l); } + else if (prot == PPPIPV6) + { + if (!config->ipv6_prefix.s6_addr[0] > 0) + { + LOG(1, s, t, "IPv6 not configured; yet received IPv6 packet. Ignoring.\n"); + return; + } + if (session[s].die) + { + LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s); + return; // closing session, PPP not processed + } + + session[s].last_packet = time_now; + if (session[s].walled_garden && !config->cluster_iam_master) + { + master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); + return; + } + + processipv6in(t, s, p, l); + } else { STAT(tunnel_rx_errors); @@ -2086,6 +2525,10 @@ static void processtun(uint8_t * buf, int len) if (*(uint16_t *) (buf + 2) == htons(PKTIP)) // IPv4 processipout(buf, len); + else if (*(uint16_t *) (buf + 2) == htons(PKTIPV6) // IPV6 + && config->ipv6_prefix.s6_addr[0] > 0) + processipv6out(buf, len); + // Else discard. } @@ -2161,7 +2604,7 @@ static int regular_cleanups(void) if (a & CLI_TUN_KILL) { LOG(2, 0, t, "Dropping tunnel by CLI\n"); - tunnelshutdown(t, "Requested by administrator"); + tunnelshutdown(t, "Requested by administrator", 1, 0, 0); } } @@ -2174,7 +2617,7 @@ static int regular_cleanups(void) if (s > config->cluster_highest_sessionid) s = 1; - if (!session[s].tunnel) // Session isn't in use + if (!session[s].opened) // Session isn't in use continue; if (!session[s].die && session[s].ip && !(session[s].flags & SF_IPCP_ACKED)) @@ -2195,13 +2638,13 @@ static int regular_cleanups(void) // Drop sessions who have not responded within IDLE_TIMEOUT seconds if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT)) { - sessionshutdown(s, "No response to LCP ECHO requests"); + sessionshutdown(s, "No response to LCP ECHO requests", 3, 0); STAT(session_timeout); if (++count >= MAX_ACTIONS) break; continue; } - // No data in IDLE_TIMEOUT seconds, send LCP ECHO + // No data in ECHO_TIMEOUT seconds, send LCP ECHO if (session[s].user[0] && (time_now - session[s].last_packet >= ECHO_TIMEOUT)) { uint8_t b[MAXCONTROL] = {0}; @@ -2229,7 +2672,7 @@ static int regular_cleanups(void) if (a & CLI_SESS_KILL) { LOG(2, s, session[s].tunnel, "Dropping session by CLI\n"); - sessionshutdown(s, "Requested by administrator"); + sessionshutdown(s, "Requested by administrator", 3, 0); a = 0; // dead, no need to check for other actions } @@ -2729,9 +3172,9 @@ static void initdata(int optdebug, char *optconfig) exit(1); } - if (!(sess_count = shared_malloc(sizeof(sessioncountt) * MAXSESSION))) + if (!(sess_local = shared_malloc(sizeof(sessionlocalt) * MAXSESSION))) { - LOG(0, 0, 0, "Error doing malloc for sessions_count: %s\n", strerror(errno)); + LOG(0, 0, 0, "Error doing malloc for sess_local: %s\n", strerror(errno)); exit(1); } @@ -2783,7 +3226,7 @@ static void initdata(int optdebug, char *optconfig) memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL); // Put all the sessions on the free list marked as undefined. - for (i = 1; i < MAXSESSION - 1; i++) + for (i = 1; i < MAXSESSION; i++) { session[i].next = i + 1; session[i].tunnel = T_UNDEF; // mark it as not filled in. @@ -2792,7 +3235,7 @@ static void initdata(int optdebug, char *optconfig) sessionfree = 1; // Mark all the tunnels as undefined (waiting to be filled in by a download). - for (i = 1; i < MAXTUNNEL- 1; i++) + for (i = 1; i < MAXTUNNEL; i++) tunnel[i].state = TUNNELUNDEF; // mark it as not filled in. if (!*hostname) @@ -2918,8 +3361,9 @@ void rebuild_address_pool(void) for (i = 0; i < MAXSESSION; ++i) { int ipid; - if (!session[i].ip || !session[i].tunnel) + if (!(session[i].opened && session[i].ip)) continue; + ipid = - lookup_ipmap(htonl(session[i].ip)); if (session[i].ip_pool_index < 0) @@ -3283,8 +3727,6 @@ int main(int argc, char *argv[]) initrad(); initippool(); - read_state(); - signal(SIGHUP, sighup_handler); signal(SIGTERM, sigterm_handler); signal(SIGINT, sigterm_handler); @@ -3376,9 +3818,6 @@ static void sigalrm_handler(int sig) static void sigterm_handler(int sig) { LOG(1, 0, 0, "Shutting down cleanly\n"); - if (config->save_state) - dump_state(); - main_quit++; } @@ -3398,7 +3837,7 @@ static void sigquit_handler(int sig) for (i = 1; i < MAXTUNNEL; i++) { if (tunnel[i].ip || tunnel[i].state) - tunnelshutdown(i, "L2TPNS Closing"); + tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0); } } @@ -3411,182 +3850,6 @@ static void sigchild_handler(int sig) ; } -static void read_state() -{ - struct stat sb; - int i; - ippoolt itmp; - FILE *f; - char magic[sizeof(DUMP_MAGIC) - 1]; - uint32_t buf[2]; - - if (!config->save_state) - { - unlink(STATEFILE); - return ; - } - - if (stat(STATEFILE, &sb) < 0) - { - unlink(STATEFILE); - return ; - } - - if (sb.st_mtime < (time(NULL) - 60)) - { - LOG(0, 0, 0, "State file is too old to read, ignoring\n"); - unlink(STATEFILE); - return ; - } - - f = fopen(STATEFILE, "r"); - unlink(STATEFILE); - - if (!f) - { - LOG(0, 0, 0, "Can't read state file: %s\n", strerror(errno)); - exit(1); - } - - if (fread(magic, sizeof(magic), 1, f) != 1 || strncmp(magic, DUMP_MAGIC, sizeof(magic))) - { - LOG(0, 0, 0, "Bad state file magic\n"); - exit(1); - } - - LOG(1, 0, 0, "Reading state information\n"); - if (fread(buf, sizeof(buf), 1, f) != 1 || buf[0] > MAXIPPOOL || buf[1] != sizeof(ippoolt)) - { - LOG(0, 0, 0, "Error/mismatch reading ip pool header from state file\n"); - exit(1); - } - - if (buf[0] > ip_pool_size) - { - LOG(0, 0, 0, "ip pool has shrunk! state = %d, current = %d\n", buf[0], ip_pool_size); - exit(1); - } - - LOG(2, 0, 0, "Loading %u ip addresses\n", buf[0]); - for (i = 0; i < buf[0]; i++) - { - if (fread(&itmp, sizeof(itmp), 1, f) != 1) - { - LOG(0, 0, 0, "Error reading ip %d from state file: %s\n", i, strerror(errno)); - exit(1); - } - - if (itmp.address != ip_address_pool[i].address) - { - LOG(0, 0, 0, "Mismatched ip %d from state file: pool may only be extended\n", i); - exit(1); - } - - memcpy(&ip_address_pool[i], &itmp, sizeof(itmp)); - } - - if (fread(buf, sizeof(buf), 1, f) != 1 || buf[0] != MAXTUNNEL || buf[1] != sizeof(tunnelt)) - { - LOG(0, 0, 0, "Error/mismatch reading tunnel header from state file\n"); - exit(1); - } - - LOG(2, 0, 0, "Loading %u tunnels\n", MAXTUNNEL); - if (fread(tunnel, sizeof(tunnelt), MAXTUNNEL, f) != MAXTUNNEL) - { - LOG(0, 0, 0, "Error reading tunnel data from state file\n"); - exit(1); - } - - for (i = 0; i < MAXTUNNEL; i++) - { - tunnel[i].controlc = 0; - tunnel[i].controls = NULL; - tunnel[i].controle = NULL; - if (*tunnel[i].hostname) - LOG(3, 0, 0, "Created tunnel for %s\n", tunnel[i].hostname); - } - - if (fread(buf, sizeof(buf), 1, f) != 1 || buf[0] != MAXSESSION || buf[1] != sizeof(sessiont)) - { - LOG(0, 0, 0, "Error/mismatch reading session header from state file\n"); - exit(1); - } - - LOG(2, 0, 0, "Loading %u sessions\n", MAXSESSION); - if (fread(session, sizeof(sessiont), MAXSESSION, f) != MAXSESSION) - { - LOG(0, 0, 0, "Error reading session data from state file\n"); - exit(1); - } - - for (i = 0; i < MAXSESSION; i++) - { - session[i].tbf_in = 0; - session[i].tbf_out = 0; - if (session[i].opened) - { - LOG(2, i, 0, "Loaded active session for user %s\n", session[i].user); - if (session[i].ip) - sessionsetup(session[i].tunnel, i); - } - } - - fclose(f); - LOG(0, 0, 0, "Loaded saved state information\n"); -} - -static void dump_state() -{ - FILE *f; - uint32_t buf[2]; - - if (!config->save_state) - return; - - do - { - if (!(f = fopen(STATEFILE, "w"))) - break; - - LOG(1, 0, 0, "Dumping state information\n"); - - if (fwrite(DUMP_MAGIC, sizeof(DUMP_MAGIC) - 1, 1, f) != 1) - break; - - LOG(2, 0, 0, "Dumping %u ip addresses\n", ip_pool_size); - buf[0] = ip_pool_size; - buf[1] = sizeof(ippoolt); - if (fwrite(buf, sizeof(buf), 1, f) != 1) - break; - if (fwrite(ip_address_pool, sizeof(ippoolt), ip_pool_size, f) != ip_pool_size) - break; - - LOG(2, 0, 0, "Dumping %u tunnels\n", MAXTUNNEL); - buf[0] = MAXTUNNEL; - buf[1] = sizeof(tunnelt); - if (fwrite(buf, sizeof(buf), 1, f) != 1) - break; - if (fwrite(tunnel, sizeof(tunnelt), MAXTUNNEL, f) != MAXTUNNEL) - break; - - LOG(2, 0, 0, "Dumping %u sessions\n", MAXSESSION); - buf[0] = MAXSESSION; - buf[1] = sizeof(sessiont); - if (fwrite(buf, sizeof(buf), 1, f) != 1) - break; - if (fwrite(session, sizeof(sessiont), MAXSESSION, f) != MAXSESSION) - break; - - if (fclose(f) == 0) - return ; // OK - } - while (0); - - LOG(0, 0, 0, "Can't write state information: %s\n", strerror(errno)); - unlink(STATEFILE); -} - static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response) { MD5_CTX ctx; @@ -3846,13 +4109,13 @@ int sessionsetup(tunnelidt t, sessionidt s) LOG(3, s, t, "Doing session setup for session\n"); - if (!session[s].ip || session[s].ip == 0xFFFFFFFE) + if (!session[s].ip) { assign_ip_address(s); if (!session[s].ip) { LOG(0, s, t, " No IP allocated. The IP address pool is FULL!\n"); - sessionshutdown(s, "No IP addresses available"); + sessionshutdown(s, "No IP addresses available", 2, 7); return 0; } LOG(3, s, t, " No IP allocated. Assigned %s from pool\n", @@ -3895,6 +4158,7 @@ int sessionsetup(tunnelidt t, sessionidt s) // convered by a Framed-Route. Anything else is part // of the IP address pool and is already routed, it // just needs to be added to the IP cache. + // IPv6 route setup is done in ppp.c, when IPV6CP is acked. if (session[s].ip_pool_index == -1) // static ip { if (!routed) routeset(s, session[s].ip, 0, 0, 1); @@ -4017,6 +4281,10 @@ int load_session(sessionidt s, sessiont *new) } } + // check v6 routing + if (new->flags & SF_IPV6_ROUTED && !(session[s].flags & SF_IPV6_ROUTED)) + route6set(s, new->ipv6route, new->ipv6prefixlen, 1); + // check filters if (new->filter_in && (new->filter_in > MAXFILTER || !ip_filters[new->filter_in - 1].name[0])) { @@ -4444,7 +4712,7 @@ void become_master(void) { for (s = 1; s <= config->cluster_highest_sessionid ; ++s) { - if (!session[s].tunnel) // Not an in-use session. + if (!session[s].opened) // Not an in-use session. continue; run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]); @@ -4476,7 +4744,7 @@ int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc for (s = 1; s <= config->cluster_highest_sessionid ; ++s) { int idle; - if (!session[s].tunnel) + if (!session[s].opened) continue; idle = time_now - session[s].last_packet; @@ -4514,7 +4782,7 @@ int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc for (s = 1; s <= config->cluster_highest_sessionid ; ++s) { int open = 0, d; - if (!session[s].tunnel) + if (!session[s].opened) continue; d = time_now - session[s].opened; @@ -4541,75 +4809,45 @@ int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc /* Unhide an avp. * - * This unencodes the AVP using the L2TP CHAP secret and the - * previously stored random vector. It replaces the hidden data with - * the cleartext data and returns the length of the cleartext data - * (including the AVP "header" of 6 bytes). - * - * Based on code from rp-l2tpd by Roaring Penguin Software Inc. + * This unencodes the AVP using the L2TP secret and the previously + * stored random vector. It overwrites the hidden data with the + * unhidden AVP subformat. */ -static int unhide_avp(uint8_t *avp, tunnelidt t, sessionidt s, uint16_t length) +static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len) { MD5_CTX ctx; - uint8_t *cursor; uint8_t digest[16]; - uint8_t working_vector[16]; - uint16_t hidden_length; - uint8_t type[2]; - size_t done, todo; - uint8_t *output; - - // Find the AVP type. - type[0] = *(avp + 4); - type[1] = *(avp + 5); - - // Line up with the hidden data - cursor = output = avp + 6; + uint8_t *last; + size_t d = 0; // Compute initial pad MD5Init(&ctx); - MD5Update(&ctx, type, 2); + MD5Update(&ctx, (uint8_t) (type >> 8) & 0xff, 1); + MD5Update(&ctx, (uint8_t) type & 0xff, 1); MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret)); - MD5Update(&ctx, session[s].random_vector, session[s].random_vector_length); + MD5Update(&ctx, vector, vec_len); MD5Final(digest, &ctx); - // Get hidden length - hidden_length = ((uint16_t) (digest[0] ^ cursor[0])) * 256 + (uint16_t) (digest[1] ^ cursor[1]); - - // Keep these for later use - working_vector[0] = *cursor; - working_vector[1] = *(cursor + 1); - cursor += 2; + // pointer to last decoded 16 octets + last = value; - if (hidden_length > length - 8) + while (len > 0) { - LOG(1, s, t, "Hidden length %d too long in AVP of length %d\n", (int) hidden_length, (int) length); - return 0; - } - - /* Decrypt remainder */ - done = 2; - todo = hidden_length; - while (todo) - { - working_vector[done] = *cursor; - *output = digest[done] ^ *cursor; - ++output; - ++cursor; - --todo; - ++done; - if (done == 16 && todo) + // calculate a new pad based on the last decoded block + if (d >= sizeof(digest)) { - // Compute new digest - done = 0; MD5Init(&ctx); MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret)); - MD5Update(&ctx, &working_vector, 16); + MD5Update(&ctx, last, sizeof(digest)); MD5Final(digest, &ctx); + + d = 0; + last = value; } - } - return hidden_length + 6; + *value++ ^= digest[d++]; + len--; + } } static int ip_filter_port(ip_filter_portt *p, uint16_t port)