drop backtrace
[l2tpns.git] / l2tpns.c
index 8b2bffd..3c90f6a 100644 (file)
--- 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 1.127 2005-09-01 06:59:06 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.152 2005-12-14 02:19:15 bodea Exp $";
 
 #include <arpa/inet.h>
 #include <assert.h>
@@ -75,6 +75,10 @@ static int syslog_log = 0;   // are we logging to syslog
 static FILE *log_stream = 0;   // file handle for direct logging (i.e. direct into file, not via syslog).
 uint32_t last_id = 0;          // Unique ID for radius accounting
 
+// calculated from config->l2tp_mtu
+uint16_t MRU = 0;              // PPP MRU
+uint16_t MSS = 0;              // TCP MSS
+
 struct cli_session_actions *cli_session_actions = NULL;        // Pending session changes requested by CLI
 struct cli_tunnel_actions *cli_tunnel_actions = NULL;  // Pending tunnel changes required by CLI
 
@@ -92,7 +96,9 @@ uint32_t eth_tx = 0;
 static uint32_t ip_pool_size = 1;      // Size of the pool of addresses used for dynamic address allocation.
 time_t time_now = 0;                   // Current time in seconds since epoch.
 static char time_now_string[64] = {0}; // Current time as a string.
+static int time_changed = 0;           // time_now changed
 char main_quit = 0;                    // True if we're in the process of exiting.
+static char main_reload = 0;           // Re-load pending
 linked_list *loaded_plugins;
 linked_list *plugins[MAX_PLUGIN_TYPES];
 
@@ -104,7 +110,8 @@ config_descriptt config_values[] = {
        CONFIG("log_file", log_filename, STRING),
        CONFIG("pid_file", pid_file, STRING),
        CONFIG("random_device", random_device, STRING),
-       CONFIG("l2tp_secret", l2tpsecret, STRING),
+       CONFIG("l2tp_secret", l2tp_secret, STRING),
+       CONFIG("l2tp_mtu", l2tp_mtu, INT),
        CONFIG("ppp_restart_time", ppp_restart_time, INT),
        CONFIG("ppp_max_configure", ppp_max_configure, INT),
        CONFIG("ppp_max_failure", ppp_max_failure, INT),
@@ -135,6 +142,7 @@ config_descriptt config_values[] = {
        CONFIG("packet_limit", max_packets, INT),
        CONFIG("cluster_address", cluster_address, IPv4),
        CONFIG("cluster_interface", cluster_interface, STRING),
+       CONFIG("cluster_mcast_ttl", cluster_mcast_ttl, INT),
        CONFIG("cluster_hb_interval", cluster_hb_interval, INT),
        CONFIG("cluster_hb_timeout", cluster_hb_timeout, INT),
        CONFIG("cluster_master_min_adv", cluster_master_min_adv, INT),
@@ -154,6 +162,7 @@ static char *plugin_functions[] = {
        "plugin_control",
        "plugin_radius_response",
        "plugin_radius_reset",
+       "plugin_radius_account",
        "plugin_become_master",
        "plugin_new_session_master",
 };
@@ -182,7 +191,6 @@ 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);
-static void sigalrm_handler(int sig);
 static void shutdown_handler(int sig);
 static void sigchild_handler(int sig);
 static void build_chap_response(uint8_t *challenge, uint8_t id, uint16_t challenge_length, uint8_t **challenge_response);
@@ -204,11 +212,17 @@ static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vec
 #define QUIT_SHUTDOWN  2 // SIGQUIT: shutdown sessions/tunnels, reject new connections
 
 // return internal time (10ths since process startup), set f if given
+// as a side-effect sets time_now, and time_changed
 static clockt now(double *f)
 {
        struct timeval t;
        gettimeofday(&t, 0);
        if (f) *f = t.tv_sec + t.tv_usec / 1000000.0;
+       if (t.tv_sec != time_now)
+       {
+           time_now = t.tv_sec;
+           time_changed++;
+       }
        return (t.tv_sec - basetime) * 10 + t.tv_usec / 100000 + 1;
 }
 
@@ -540,6 +554,13 @@ static void inittun(void)
                LOG(0, 0, 0, "Error setting tun queue length: %s\n", strerror(errno));
                exit(1);
        }
+       /* set MTU to modem MRU + 4 (tun header) */
+       ifr.ifr_mtu = MRU + 4;
+       if (ioctl(ifrfd, SIOCSIFMTU, (void *) &ifr) < 0)
+       {
+               LOG(0, 0, 0, "Error setting tun MTU: %s\n", strerror(errno));
+               exit(1);
+       }
        ifr.ifr_flags = IFF_UP;
        if (ioctl(ifrfd, SIOCSIFFLAGS, (void *) &ifr) < 0)
        {
@@ -919,18 +940,14 @@ void tunnelsend(uint8_t * buf, uint16_t l, tunnelidt t)
 
        if (!t)
        {
-               static int backtrace_count = 0;
                LOG(0, 0, t, "tunnelsend called with 0 as tunnel id\n");
                STAT(tunnel_tx_errors);
-               log_backtrace(backtrace_count, 5)
                return;
        }
 
        if (!tunnel[t].ip)
        {
-               static int backtrace_count = 0;
                LOG(1, 0, t, "Error sending data out tunnel: no remote endpoint (tunnel not set up)\n");
-               log_backtrace(backtrace_count, 5)
                STAT(tunnel_tx_errors);
                return;
        }
@@ -948,7 +965,7 @@ void tunnelsend(uint8_t * buf, uint16_t l, tunnelidt t)
        {
                tunnel[t].last = time_now; // control message sent
                tunnel[t].retry = backoff(tunnel[t].try); // when to resend
-               if (tunnel[t].try > 1)
+               if (tunnel[t].try)
                {
                        STAT(tunnel_retries);
                        LOG(3, 0, t, "Control message resend try %d\n", tunnel[t].try);
@@ -977,6 +994,61 @@ int tun_write(uint8_t * data, int size)
        return write(tunfd, data, size);
 }
 
+// adjust tcp mss to avoid fragmentation (called only for tcp packets with syn set)
+void adjust_tcp_mss(sessionidt s, tunnelidt t, uint8_t *buf, int len, uint8_t *tcp)
+{
+       int d = (tcp[12] >> 4) * 4;
+       uint8_t *mss = 0;
+       uint8_t *opts;
+       uint8_t *data;
+       uint16_t orig;
+       uint32_t sum;
+
+       if ((tcp[13] & 0x3f) & ~(TCP_FLAG_SYN|TCP_FLAG_ACK)) // only want SYN and SYN,ACK
+               return;
+
+       if (tcp + d > buf + len) // short?
+               return;
+
+       opts = tcp + 20;
+       data = tcp + d;
+
+       while (opts < data)
+       {
+               if (*opts == 2 && opts[1] == 4) // mss option (2), length 4
+               {
+                       mss = opts + 2;
+                       if (mss + 2 > data) return; // short?
+                       break;
+               }
+
+               if (*opts == 0) return; // end of options
+               if (*opts == 1 || !opts[1]) // no op (one byte), or no length (prevent loop)
+                       opts++;
+               else
+                       opts += opts[1]; // skip over option
+       }
+
+       if (!mss) return; // not found
+       orig = ntohs(*(uint16_t *) mss);
+
+       if (orig <= MSS) return; // mss OK
+
+       LOG(5, s, t, "TCP: %s:%u -> %s:%u SYN%s: adjusted mss from %u to %u\n",
+               fmtaddr(*(in_addr_t *) (buf + 12), 0), ntohs(*(uint16_t *) tcp),
+               fmtaddr(*(in_addr_t *) (buf + 16), 1), ntohs(*(uint16_t *) (tcp + 2)),
+               (tcp[13] & TCP_FLAG_ACK) ? ",ACK" : "", orig, MSS);
+
+       // set mss
+       *(int16_t *) mss = htons(MSS);
+
+       // adjust checksum (see rfc1141)
+       sum = orig + (~MSS & 0xffff);
+       sum += ntohs(*(uint16_t *) (tcp + 16));
+       sum = (sum & 0xffff) + (sum >> 16);
+       *(uint16_t *) (tcp + 16) = htons(sum + (sum >> 16));
+}
+
 // process outgoing (to tunnel) IP
 //
 static void processipout(uint8_t *buf, int len)
@@ -1084,6 +1156,14 @@ static void processipout(uint8_t *buf, int len)
        if (session[s].filter_out && !ip_filter(buf, len, session[s].filter_out - 1))
                return;
 
+       // adjust MSS on SYN and SYN,ACK packets with options
+       if ((ntohs(*(uint16_t *) (buf + 6)) & 0x1fff) == 0 && buf[9] == IPPROTO_TCP) // first tcp fragment
+       {
+               int ihl = (buf[0] & 0xf) * 4; // length of IP header
+               if (len >= ihl + 20 && (buf[ihl + 13] & TCP_FLAG_SYN) && ((buf[ihl + 12] >> 4) > 5))
+                       adjust_tcp_mss(s, t, buf, len, buf + ihl);
+       }
+
        if (sp->tbf_out)
        {
                // Are we throttling this session?
@@ -1093,7 +1173,8 @@ static void processipout(uint8_t *buf, int len)
                        master_throttle_packet(sp->tbf_out, data, size);
                return;
        }
-       else if (sp->walled_garden && !config->cluster_iam_master)
+
+       if (sp->walled_garden && !config->cluster_iam_master)
        {
                // We are walled-gardening this
                master_garden_packet(s, data, size);
@@ -1605,6 +1686,7 @@ void sendipcp(sessionidt s, tunnelidt t)
                                 my_address; // send my IP
 
        tunnelsend(buf, 10 + (q - buf), t); // send it
+       restart_timer(s, ipcp);
 }
 
 void sendipv6cp(sessionidt s, tunnelidt t)
@@ -1630,6 +1712,7 @@ void sendipv6cp(sessionidt s, tunnelidt t)
        q[13] = 1;
 
        tunnelsend(buf, 14 + (q - buf), t);     // send it
+       restart_timer(s, ipv6cp);
 }
 
 static void sessionclear(sessionidt s)
@@ -1826,6 +1909,11 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                return;
        }
        l -= (p - buf);
+
+       // used to time out old tunnels
+       if (t && tunnel[t].state == TUNNELOPEN)
+               tunnel[t].lastrec = time_now;
+
        if (*buf & 0x80)
        {                          // control
                uint16_t message = 0xFFFF;      // message type
@@ -1913,9 +2001,6 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                        return;
                }
 
-               // This is used to time out old tunnels
-               tunnel[t].lastrec = time_now;
-
                // check sequence of this message
                {
                        int skip = tunnel[t].window; // track how many in-window packets are still in queue
@@ -2005,7 +2090,7 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                                        uint16_t orig_len;
 
                                        // handle hidden AVPs
-                                       if (!*config->l2tpsecret)
+                                       if (!*config->l2tp_secret)
                                        {
                                                LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
                                                fatal = flags;
@@ -2248,9 +2333,9 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                                                        if (*p == 5 && p[1] == 6) // Magic-Number
                                                                amagic = ntohl(*(uint32_t *) (p + 2));
                                                        else if (*p == 7) // Protocol-Field-Compression
-                                                               aflags |= SESSIONPFC;
+                                                               aflags |= SESSION_PFC;
                                                        else if (*p == 8) // Address-and-Control-Field-Compression
-                                                               aflags |= SESSIONACFC;
+                                                               aflags |= SESSION_ACFC;
                                                        p += p[1];
                                                }
                                        }
@@ -2377,19 +2462,17 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                                case 12:      // ICCN
                                        if (amagic == 0) amagic = time_now;
                                        session[s].magic = amagic; // set magic number
-                                       session[s].l2tp_flags = aflags; // set flags received
-                                       session[s].mru = DEFAULT_MRU;
+                                       session[s].flags = aflags; // set flags received
+                                       session[s].mru = PPPMTU; // default
                                        controlnull(t); // ack
 
                                        // start LCP
-                                       sess_local[s].lcp.restart = time_now + config->ppp_restart_time;
-                                       sess_local[s].lcp.conf_sent = 1;
-                                       sess_local[s].lcp.nak_sent = 0;
                                        sess_local[s].lcp_authtype = config->radius_authprefer;
-                                       session[s].ppp.lcp = RequestSent;
+                                       sess_local[s].ppp_mru = MRU;
                                        sendlcp(s, t);
-
+                                       change_state(s, lcp, RequestSent);
                                        break;
+
                                case 14:      // CDN
                                        controlnull(t); // ack
                                        sessionshutdown(s, "Closed (Received CDN).", 0, 0);
@@ -2415,7 +2498,7 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
        }
        else
        {                          // data
-               uint16_t prot;
+               uint16_t proto;
 
                LOG_HEX(5, "Receive Tunnel Data", p, l);
                if (l > 2 && p[0] == 0xFF && p[1] == 0x03)
@@ -2431,12 +2514,12 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                }
                if (*p & 1)
                {
-                       prot = *p++;
+                       proto = *p++;
                        l--;
                }
                else
                {
-                       prot = ntohs(*(uint16_t *) p);
+                       proto = ntohs(*(uint16_t *) p);
                        p += 2;
                        l -= 2;
                }
@@ -2456,43 +2539,43 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                        return;
                }
 
-               if (prot == PPPPAP)
+               if (proto == PPPPAP)
                {
                        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; }
                        processpap(s, t, p, l);
                }
-               else if (prot == PPPCHAP)
+               else if (proto == PPPCHAP)
                {
                        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; }
                        processchap(s, t, p, l);
                }
-               else if (prot == PPPLCP)
+               else if (proto == PPPLCP)
                {
                        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; }
                        processlcp(s, t, p, l);
                }
-               else if (prot == PPPIPCP)
+               else if (proto == PPPIPCP)
                {
                        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; }
                        processipcp(s, t, p, l);
                }
-               else if (prot == PPPIPV6CP)
+               else if (proto == PPPIPV6CP && config->ipv6_prefix.s6_addr[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(s, t, p, l);
                }
-               else if (prot == PPPCCP)
+               else if (proto == PPPCCP)
                {
                        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; }
                        processccp(s, t, p, l);
                }
-               else if (prot == PPPIP)
+               else if (proto == PPPIP)
                {
                        if (session[s].die)
                        {
@@ -2509,13 +2592,8 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 
                        processipin(s, t, p, l);
                }
-               else if (prot == PPPIPV6)
+               else if (proto == PPPIPV6 && config->ipv6_prefix.s6_addr[0])
                {
-                       if (!config->ipv6_prefix.s6_addr[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);
@@ -2531,10 +2609,16 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
 
                        processipv6in(s, t, p, l);
                }
+               else if (session[s].ppp.lcp == Opened)
+               {
+                       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; }
+                       protoreject(s, t, p, l, proto);
+               }
                else
                {
-                       STAT(tunnel_rx_errors);
-                       LOG(1, s, t, "Unknown PPP protocol %04X\n", prot);
+                       LOG(2, s, t, "Unknown PPP protocol 0x%04X received in LCP %s state\n",
+                               proto, ppp_state(session[s].ppp.lcp));
                }
        }
 }
@@ -2645,7 +2729,7 @@ static void regular_cleanups(double period)
                        }
                }
                // Send hello
-               if (tunnel[t].state == TUNNELOPEN && (time_now - tunnel[t].lastrec) > 60)
+               if (tunnel[t].state == TUNNELOPEN && !tunnel[t].controlc && (time_now - tunnel[t].lastrec) > 60)
                {
                        controlt *c = controlnew(6); // sending HELLO
                        controladd(c, 0, t); // send the message
@@ -2716,8 +2800,6 @@ static void regular_cleanups(double period)
                                if (sess_local[s].lcp.conf_sent < config->ppp_max_configure)
                                {
                                        LOG(3, s, session[s].tunnel, "No ACK for LCP ConfigReq... resending\n");
-                                       sess_local[s].lcp.restart = time_now + config->ppp_restart_time;
-                                       sess_local[s].lcp.conf_sent++;
                                        sendlcp(s, session[s].tunnel);
                                        change_state(s, lcp, next_state);
                                }
@@ -2747,8 +2829,6 @@ static void regular_cleanups(double period)
                                if (sess_local[s].ipcp.conf_sent < config->ppp_max_configure)
                                {
                                        LOG(3, s, session[s].tunnel, "No ACK for IPCP ConfigReq... resending\n");
-                                       sess_local[s].ipcp.restart = time_now + config->ppp_restart_time;
-                                       sess_local[s].ipcp.conf_sent++;
                                        sendipcp(s, session[s].tunnel);
                                        change_state(s, ipcp, next_state);
                                }
@@ -2778,8 +2858,6 @@ static void regular_cleanups(double period)
                                if (sess_local[s].ipv6cp.conf_sent < config->ppp_max_configure)
                                {
                                        LOG(3, s, session[s].tunnel, "No ACK for IPV6CP ConfigReq... resending\n");
-                                       sess_local[s].ipv6cp.restart = time_now + config->ppp_restart_time;
-                                       sess_local[s].ipv6cp.conf_sent++;
                                        sendipv6cp(s, session[s].tunnel);
                                        change_state(s, ipv6cp, next_state);
                                }
@@ -2806,8 +2884,6 @@ static void regular_cleanups(double period)
                                if (sess_local[s].ccp.conf_sent < config->ppp_max_configure)
                                {
                                        LOG(3, s, session[s].tunnel, "No ACK for CCP ConfigReq... resending\n");
-                                       sess_local[s].ccp.restart = time_now + config->ppp_restart_time;
-                                       sess_local[s].ccp.conf_sent++;
                                        sendccp(s, session[s].tunnel);
                                        change_state(s, ccp, next_state);
                                }
@@ -2831,7 +2907,8 @@ static void regular_cleanups(double period)
                }
 
                // No data in ECHO_TIMEOUT seconds, send LCP ECHO
-               if (session[s].ppp.phase >= Establish && (time_now - session[s].last_packet >= ECHO_TIMEOUT))
+               if (session[s].ppp.phase >= Establish && (time_now - session[s].last_packet >= ECHO_TIMEOUT) &&
+                       (time_now - sess_local[s].last_echo >= ECHO_TIMEOUT))
                {
                        uint8_t b[MAXETHER];
 
@@ -2846,6 +2923,7 @@ static void regular_cleanups(double period)
                        LOG(4, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
                                        (int)(time_now - session[s].last_packet));
                        tunnelsend(b, 24, session[s].tunnel); // send it
+                       sess_local[s].last_echo = time_now;
                        s_actions++;
                }
 
@@ -3135,9 +3213,17 @@ static void mainloop(void)
                int more = 0;
                int n;
 
+
+               if (main_reload)
+               {
+                       main_reload = 0;
+                       read_config_file();
+                       config->reload_config++;
+               }
+
                if (config->reload_config)
                {
-                       // Update the config state based on config settings
+                       config->reload_config = 0;
                        update_config();
                }
 
@@ -3301,6 +3387,35 @@ static void mainloop(void)
                        }
                }
 
+               if (time_changed)
+               {
+                       double Mbps = 1024.0 * 1024.0 / 8 * time_changed;
+
+                       // Log current traffic stats
+                       snprintf(config->bandwidth, sizeof(config->bandwidth),
+                               "UDP-ETH:%1.0f/%1.0f  ETH-UDP:%1.0f/%1.0f  TOTAL:%0.1f   IN:%u OUT:%u",
+                               (udp_rx / Mbps), (eth_tx / Mbps), (eth_rx / Mbps), (udp_tx / Mbps),
+                               ((udp_tx + udp_rx + eth_tx + eth_rx) / Mbps),
+                               udp_rx_pkt / time_changed, eth_rx_pkt / time_changed);
+                
+                       udp_tx = udp_rx = 0;
+                       udp_rx_pkt = eth_rx_pkt = 0;
+                       eth_tx = eth_rx = 0;
+                       time_changed = 0;
+                
+                       if (config->dump_speed)
+                               printf("%s\n", config->bandwidth);
+                
+                       // Update the internal time counter
+                       strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
+                
+                       {
+                               // Run timer hooks
+                               struct param_timer p = { time_now };
+                               run_plugins(PLUGIN_TIMER, &p);
+                       }
+               }
+
                        // Runs on every machine (master and slaves).
                if (next_cluster_ping <= TIME)
                {
@@ -3469,6 +3584,7 @@ static void initdata(int optdebug, char *optconfig)
        config->debug = optdebug;
        config->num_tbfs = MAXTBFS;
        config->rl_rate = 28; // 28kbps
+       config->cluster_mcast_ttl = 1;
        config->cluster_master_min_adv = 1;
        config->ppp_restart_time = 3;
        config->ppp_max_configure = 10;
@@ -3975,14 +4091,13 @@ int main(int argc, char *argv[])
        // Start the timer routine off
        time(&time_now);
        strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
-       signal(SIGALRM, sigalrm_handler);
-       siginterrupt(SIGALRM, 0);
 
        initplugins();
        initdata(optdebug, optconfig);
 
        init_cli(hostname);
        read_config_file();
+       update_config();
        init_tbf(config->num_tbfs);
 
        LOG(0, 0, 0, "L2TPNS version " VERSION "\n");
@@ -4058,8 +4173,6 @@ int main(int argc, char *argv[])
                        LOG(0, 0, 0, "Can't lock pages: %s\n", strerror(errno));
        }
 
-       alarm(1);
-
        // Drop privileges here
        if (config->target_uid > 0 && geteuid() == 0)
                setuid(config->target_uid);
@@ -4081,53 +4194,11 @@ int main(int argc, char *argv[])
 
 static void sighup_handler(int sig)
 {
-       if (log_stream)
-       {
-               if (log_stream != stderr)
-                       fclose(log_stream);
-
-               log_stream = NULL;
-       }
-
-       read_config_file();
-}
-
-static void sigalrm_handler(int sig)
-{
-       // Log current traffic stats
-
-       snprintf(config->bandwidth, sizeof(config->bandwidth),
-               "UDP-ETH:%1.0f/%1.0f  ETH-UDP:%1.0f/%1.0f  TOTAL:%0.1f   IN:%u OUT:%u",
-               (udp_rx / 1024.0 / 1024.0 * 8),
-               (eth_tx / 1024.0 / 1024.0 * 8),
-               (eth_rx / 1024.0 / 1024.0 * 8),
-               (udp_tx / 1024.0 / 1024.0 * 8),
-               ((udp_tx + udp_rx + eth_tx + eth_rx) / 1024.0 / 1024.0 * 8),
-               udp_rx_pkt, eth_rx_pkt);
-
-       udp_tx = udp_rx = 0;
-       udp_rx_pkt = eth_rx_pkt = 0;
-       eth_tx = eth_rx = 0;
-
-       if (config->dump_speed)
-               printf("%s\n", config->bandwidth);
-
-       // Update the internal time counter
-       time(&time_now);
-       strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
-       alarm(1);
-
-       {
-               // Run timer hooks
-               struct param_timer p = { time_now };
-               run_plugins(PLUGIN_TIMER, &p);
-       }
-
+       main_reload++;
 }
 
 static void shutdown_handler(int sig)
 {
-       LOG(1, 0, 0, "Shutting down\n");
        main_quit = (sig == SIGQUIT) ? QUIT_SHUTDOWN : QUIT_FAILOVER;
 }
 
@@ -4142,7 +4213,7 @@ static void build_chap_response(uint8_t *challenge, uint8_t id, uint16_t challen
        MD5_CTX ctx;
        *challenge_response = NULL;
 
-       if (!*config->l2tpsecret)
+       if (!*config->l2tp_secret)
        {
                LOG(0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
                return;
@@ -4154,7 +4225,7 @@ static void build_chap_response(uint8_t *challenge, uint8_t id, uint16_t challen
 
        MD5_Init(&ctx);
        MD5_Update(&ctx, &id, 1);
-       MD5_Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
+       MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
        MD5_Update(&ctx, challenge, challenge_length);
        MD5_Final(*challenge_response, &ctx);
 
@@ -4221,6 +4292,17 @@ static void update_config()
                setbuf(log_stream, NULL);
        }
 
+#define L2TP_HDRS              (20+8+6+4)      // L2TP data encaptulation: ip + udp + l2tp (data) + ppp (inc hdlc)
+#define TCP_HDRS               (20+20)         // TCP encapsulation: ip + tcp
+
+       if (config->l2tp_mtu <= 0)              config->l2tp_mtu = PPPMTU;
+       else if (config->l2tp_mtu < MINMTU)     config->l2tp_mtu = MINMTU;
+       else if (config->l2tp_mtu > MAXMTU)     config->l2tp_mtu = MAXMTU;
+
+       // reset MRU/MSS globals
+       MRU = config->l2tp_mtu - L2TP_HDRS;
+       MSS = MRU - TCP_HDRS;
+
        // Update radius
        config->numradiusservers = 0;
        for (i = 0; i < MAXRADSERVER; i++)
@@ -4366,8 +4448,6 @@ static void update_config()
                        LOG(0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
                }
        }
-
-       config->reload_config = 0;
 }
 
 static void read_config_file()
@@ -4385,7 +4465,6 @@ static void read_config_file()
        cli_do_file(f);
        LOG(3, 0, 0, "Done reading config file\n");
        fclose(f);
-       update_config();
 }
 
 int sessionsetup(sessionidt s, tunnelidt t)
@@ -5119,7 +5198,7 @@ static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vec
        // Compute initial pad
        MD5_Init(&ctx);
        MD5_Update(&ctx, (unsigned char *) &m, 2);
-       MD5_Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
+       MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
        MD5_Update(&ctx, vector, vec_len);
        MD5_Final(digest, &ctx);
 
@@ -5132,7 +5211,7 @@ static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vec
                if (d >= sizeof(digest))
                {
                        MD5_Init(&ctx);
-                       MD5_Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
+                       MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
                        MD5_Update(&ctx, last, sizeof(digest));
                        MD5_Final(digest, &ctx);
 
@@ -5255,7 +5334,9 @@ int ip_filter(uint8_t *buf, int len, uint8_t filter)
 
                if (frag_offset)
                {
-                       if (!rule->frag || rule->action == FILTER_ACTION_DENY)
+                       // layer 4 deny rules are skipped
+                       if (rule->action == FILTER_ACTION_DENY &&
+                           (rule->src_ports.op || rule->dst_ports.op || rule->tcp_flag_op))
                                continue;
                }
                else