validate source of RADIUS packets

[l2tpns.git] / l2tpns.c

diff --git a/l2tpns.c b/l2tpns.c
index c66400d..9e949cd 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 1.149 2005-11-17 06:46:24 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.156 2006-02-17 13:27:07 bodea Exp $";
 
 #include <arpa/inet.h>
 #include <assert.h>
@@ -96,9 +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.
-int time_changed = 0;                  // time_now changed
+static int time_changed = 0;           // time_now changed
 char main_quit = 0;                    // True if we're in the process of exiting.
-char main_reload = 0;                  // Re-load pending
+static char main_reload = 0;           // Re-load pending
 linked_list *loaded_plugins;
 linked_list *plugins[MAX_PLUGIN_TYPES];
 
@@ -554,6 +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 */
+       ifr.ifr_mtu = MRU;
+       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)
        {
@@ -933,18 +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;
        }
@@ -2460,7 +2463,7 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                                        if (amagic == 0) amagic = time_now;
                                        session[s].magic = amagic; // set magic number
                                        session[s].flags = aflags; // set flags received
-                                       session[s].mru = PPPMTU; // default
+                                       session[s].mru = PPPoE_MRU; // default
                                        controlnull(t); // ack
 
                                        // start LCP
@@ -2608,29 +2611,9 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
                }
                else if (session[s].ppp.lcp == Opened)
                {
-                       uint8_t buf[MAXETHER];
-                       uint8_t *q;
-                       int mru = session[s].mru;
-                       if (mru > sizeof(buf)) mru = sizeof(buf);
-
-                       l += 6;
-                       if (l > mru) l = mru;
-
-                       q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPLCP);
-                       if (!q) return;
-
-                       *q = ProtocolRej;
-                       *(q + 1) = ++sess_local[s].lcp_ident;
-                       *(uint16_t *)(q + 2) = htons(l);
-                       *(uint16_t *)(q + 4) = htons(proto);
-                       memcpy(q + 6, p, l - 6);
-
-                       if (proto == PPPIPV6CP)
-                               LOG(3, s, t, "LCP: send ProtocolRej (IPV6CP: not configured)\n");
-                       else
-                               LOG(2, s, t, "LCP: sent ProtocolRej (0x%04X: unsupported)\n", proto);
-
-                       tunnelsend(buf, l + (q - buf), t);
+                       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
                {
@@ -2935,7 +2918,7 @@ static void regular_cleanups(double period)
                        *q = EchoReq;
                        *(uint8_t *)(q + 1) = (time_now % 255); // ID
                        *(uint16_t *)(q + 2) = htons(8); // Length
-                       *(uint32_t *)(q + 4) = 0; // Magic Number (not supported)
+                       *(uint32_t *)(q + 4) = session[s].ppp.lcp == Opened ? htonl(session[s].magic) : 0; // Magic Number
 
                        LOG(4, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
                                        (int)(time_now - session[s].last_packet));
@@ -3318,9 +3301,17 @@ static void mainloop(void)
                                        break;
 
                                case FD_TYPE_RADIUS: // RADIUS response
-                                       s = recv(radfds[d->index], buf, sizeof(buf), 0);
+                                       alen = sizeof(addr);
+                                       s = recvfrom(radfds[d->index], buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen);
                                        if (s >= 0 && config->cluster_iam_master)
-                                               processrad(buf, s, d->index);
+                                       {
+                                               if (addr.sin_addr.s_addr == config->radiusserver[0] ||
+                                                   addr.sin_addr.s_addr == config->radiusserver[1])
+                                                       processrad(buf, s, d->index);
+                                               else
+                                                       LOG(3, 0, 0, "Dropping RADIUS packet from unknown source %s\n",
+                                                               fmtaddr(addr.sin_addr.s_addr, 0));
+                                       }
 
                                        n--;
                                        break;
@@ -3966,7 +3957,7 @@ static void initippool()
                else
                {
                        // It's a single ip address
-                       add_to_ip_pool(inet_addr(pool), 0);
+                       add_to_ip_pool(ntohl(inet_addr(pool)), 0);
                }
        }
        fclose(f);
@@ -4312,12 +4303,15 @@ static void update_config()
 #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;
+       if (config->l2tp_mtu <= 0)              config->l2tp_mtu = 1500; // ethernet default
        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;
+       if (MRU > PPPoE_MRU)
+               MRU = PPPoE_MRU;
+
        MSS = MRU - TCP_HDRS;
 
        // Update radius