Ensure that sessionkill is not called on an unopened session (borks the freelist).

Fix off-by-one errors in session/tunnel initialisation and sessiont <-> sessionidt functions.
Use session[s].opened consistently when checking for in-use sessions (rather than session[s].tunnel).
Use <= cluster_highest_sessionid rather than < MAXSESSION in a couple of loops.

diff --git a/l2tpns.c b/l2tpns.c
index 56e1377..e65a9c1 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
 
 // 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 1.73.2.4 2005/01/13 08:43:19 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.73.2.5 2005/02/14 06:00:57 bodea Exp $";

 
 #include <arpa/inet.h>
 #include <assert.h>
 
 #include <arpa/inet.h>
 #include <assert.h>


@@ -479,7 +479,7 @@ sessionidt sessionbyip(in_addr_t ip)
        int s = lookup_ipmap(ip);
        CSTAT(call_sessionbyip);
 
        int s = lookup_ipmap(ip);
        CSTAT(call_sessionbyip);
 

-       if (s > 0 && s < MAXSESSION && session[s].tunnel)
+       if (s > 0 && s < MAXSESSION && session[s].opened)

                return (sessionidt) s;
 
        return 0;
                return (sessionidt) s;
 
        return 0;


@@ -579,8 +579,11 @@ sessionidt sessionbyuser(char *username)
        int s;
        CSTAT(call_sessionbyuser);
 
        int s;
        CSTAT(call_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.
 
                if (session[s].walled_garden)
                        continue;               // Skip walled garden users.
 


@@ -622,17 +625,16 @@ void send_garp(in_addr_t ip)
        sendarp(ifr.ifr_ifindex, mac, ip);
 }
 
        sendarp(ifr.ifr_ifindex, mac, ip);
 }
 

-// Find session by username, 0 for not found

 static sessiont *sessiontbysessionidt(sessionidt s)
 {
 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;
        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;
 }
 
        return val;
 }
 


@@ -1012,7 +1014,7 @@ static void controladd(controlt * c, tunnelidt t, sessionidt s)
 //
 void throttle_session(sessionidt s, int rate_in, int rate_out)
 {
 //
 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)
                return; // No-one home.
 
        if (!*session[s].user)


@@ -1050,7 +1052,7 @@ 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)
 {
 // add/remove filters from session (-1 = no change)
 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)
                return; // No-one home.
 
        if (!*session[s].user)


@@ -1093,9 +1095,9 @@ void sessionshutdown(sessionidt s, char *reason)
 
        CSTAT(call_sessionshutdown);
 
 
        CSTAT(call_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
        }
 
                return;                   // not a live session
        }
 


@@ -1167,7 +1169,7 @@ void sessionshutdown(sessionidt s, char *reason)
        }
 
        if (!session[s].die)
        }
 
        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--;
 
        // update filter refcounts
        if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;


@@ -1218,12 +1220,21 @@ void sendipcp(tunnelidt t, sessionidt s)
 }
 
 // kill a session now
 }
 
 // kill a session now

-static void sessionkill(sessionidt s, char *reason)
+void sessionkill(sessionidt s, char *reason)

 {
 
        CSTAT(call_sessionkill);
 
 {
 
        CSTAT(call_sessionkill);
 

-       session[s].die = now();
+       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);  // close radius/routes, etc.
        if (session[s].radius)
                radiusclear(session[s].radius, s); // cant send clean accounting data, session is killed
        sessionshutdown(s, reason);  // close radius/routes, etc.
        if (session[s].radius)
                radiusclear(session[s].radius, s); // cant send clean accounting data, session is killed


@@ -1265,7 +1276,7 @@ static void tunnelkill(tunnelidt t, char *reason)
                controlfree = c;
        }
        // kill sessions
                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);
 
                if (session[s].tunnel == t)
                        sessionkill(s, reason);
 


@@ -1292,12 +1303,12 @@ static void tunnelshutdown(tunnelidt t, char *reason)
        LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
 
        // close session
        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);
 
        tunnel[t].state = TUNNELDIE;
                if (session[s].tunnel == t)
                        sessionshutdown(s, reason);
 
        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
        cluster_send_tunnel(t);
        // TBA - should we wait for sessions to stop?
        {                            // Send StopCCN


@@ -1836,7 +1847,8 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                                        if (!sessionfree)
                                        {
                                                STAT(session_overflow);
                                        if (!sessionfree)
                                        {
                                                STAT(session_overflow);

-                                               tunnelshutdown(t, "No free sessions");
+                                               LOG(1, 0, t, "No free sessions");
+                                               return;

                                        }
                                        else
                                        {
                                        }
                                        else
                                        {


@@ -1860,7 +1872,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
 
                                                c = controlnew(11); // sending ICRP
                                                session[s].id = sessionid++;
 
                                                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;
                                                session[s].tunnel = t;
                                                session[s].far = asession;
                                                session[s].last_packet = time_now;


@@ -1943,7 +1955,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                        l -= 2;
                }
 
                        l -= 2;
                }
 

-               if (s && !session[s].tunnel)    // Is something wrong??
+               if (s && !session[s].opened)    // Is something wrong??

                {
                        if (!config->cluster_iam_master)
                        {
                {
                        if (!config->cluster_iam_master)
                        {


@@ -1952,10 +1964,7 @@ void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
                                return;
                        }
 
                                return;
                        }
 

-
-                       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;
                }
                        STAT(tunnel_rx_errors);
                        return;
                }


@@ -2123,7 +2132,7 @@ static int regular_cleanups(void)
                if (s > config->cluster_highest_sessionid)
                        s = 1;
 
                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))
                        continue;
 
                if (!session[s].die && session[s].ip && !(session[s].flags & SF_IPCP_ACKED))


@@ -2731,7 +2740,7 @@ memset(ip_filters, 0, sizeof(ip_filtert) * MAXFILTER);
        memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
 
                // Put all the sessions on the free list marked as undefined.
        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.
        {
                session[i].next = i + 1;
                session[i].tunnel = T_UNDEF;    // mark it as not filled in.


@@ -2740,7 +2749,7 @@ memset(ip_filters, 0, sizeof(ip_filtert) * MAXFILTER);
        sessionfree = 1;
 
                // Mark all the tunnels as undefined (waiting to be filled in by a download).
        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)
                tunnel[i].state = TUNNELUNDEF;  // mark it as not filled in.
 
        if (!*hostname)


@@ -2866,7 +2875,7 @@ void rebuild_address_pool(void)
        for (i = 0; i < MAXSESSION; ++i)
        {
                int ipid;
        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));
 
                        continue;
                ipid = - lookup_ipmap(htonl(session[i].ip));
 


@@ -3739,7 +3748,7 @@ int sessionsetup(tunnelidt t, sessionidt s)
 
        LOG(3, s, t, "Doing session setup for session\n");
 
 
        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)
        {
                assign_ip_address(s);
                if (!session[s].ip)


@@ -4337,7 +4346,7 @@ void become_master(void)
        {
                for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
                {
        {
                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]);
                                continue;
 
                        run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);


@@ -4369,7 +4378,7 @@ 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;
        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;
                        continue;
 
                idle = time_now - session[s].last_packet;


@@ -4407,7 +4416,7 @@ 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;
        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;
                        continue;
 
                d = time_now - session[s].opened;