Merged revisions 221769 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r221769 | rmudgett | 2009-10-01 18:18:28 -0500 (Thu, 01 Oct 2009) | 26 lines

  Occasionally losing use of B channels in chan_misdn.

  I have not been able to reproduce the problem of losing channels.
  However, I have seen in the code a reentrancy problem that might give
  these symptoms.

  The reentrancy patch does several things:
  1) Guards B channel and B channel structure allocation.
  2) Makes the B channel structure find routines more precise in locating records.
  3) Never leave a B channel allocated if we received cause 44.

  The last item may cause temporary outgoing call problems, but they should
  clear when the line becomes idle.

  (closes issue #15490)
  Reported by: slutec18
  Patches:
        issue15490_channel_alloc_reentrancy.patch uploaded by rmudgett (license 664)
  Tested by: rmudgett, slutec18

  (closes issue #15458)
  Reported by: FabienToune
  Patches:
        issue15458_channel_alloc_reentrancy.patch uploaded by rmudgett (license 664)
  Tested by: FabienToune, rmudgett, slutec18
........

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@221844 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/misdn/isdn_lib.c b/channels/misdn/isdn_lib.c
index 43c69ddff8fb474cf35cb94073d438640247ee0e..2acf8f0897bb92af1af131ad6199ebb0d960858c 100644 (file)
--- a/channels/misdn/isdn_lib.c
+++ b/channels/misdn/isdn_lib.c
@@ -528,6 +528,7 @@ static int find_free_chan_in_stack(struct misdn_stack *stack, struct misdn_bchan
 
 #if defined(AST_MISDN_ENHANCEMENTS)
        if (bc->is_register_pool) {
+               pthread_mutex_lock(&stack->st_lock);
                for (i = MAX_BCHANS + 1; i < ARRAY_LEN(stack->channels); ++i) {
                        if (!stack->channels[i]) {
                                chan = i + 1;
@@ -547,6 +548,7 @@ static int find_free_chan_in_stack(struct misdn_stack *stack, struct misdn_bchan
 
                --channel;
 
+               pthread_mutex_lock(&stack->st_lock);
                bnums = stack->pri ? stack->b_num : stack->b_num - 1;
                if (dec) {
                        for (i = bnums; i >= 0; --i) {
@@ -572,6 +574,7 @@ static int find_free_chan_in_stack(struct misdn_stack *stack, struct misdn_bchan
        }
 
        if (!chan) {
+               pthread_mutex_unlock(&stack->st_lock);
                cb_log(1, stack->port, " !! NO FREE CHAN IN STACK\n");
                dump_chan_list(stack);
                bc->out_cause = AST_CAUSE_NORMAL_CIRCUIT_CONGESTION;
@@ -579,10 +582,12 @@ static int find_free_chan_in_stack(struct misdn_stack *stack, struct misdn_bchan
        }
 
        if (set_chan_in_stack(stack, chan) < 0) {
+               pthread_mutex_unlock(&stack->st_lock);
                cb_log(0, stack->port, "Channel Already in use:%d\n", chan);
                bc->out_cause = AST_CAUSE_REQUESTED_CHAN_UNAVAIL;
                return -1;
        }
+       pthread_mutex_unlock(&stack->st_lock);
 
        bc->channel = chan;
        return 0;
@@ -865,15 +870,15 @@ static void clear_l3(struct misdn_stack *stack)
        if (global_state == MISDN_INITIALIZED) {
                for (i = 0; i <= stack->b_num; ++i) {
                        cb_event(EVENT_CLEANUP, &stack->bc[i], NULL);
-                       empty_chan_in_stack(stack, i + 1);
                        empty_bc(&stack->bc[i]);
                        clean_up_bc(&stack->bc[i]);
+                       empty_chan_in_stack(stack, i + 1);
                        stack->bc[i].in_use = 0;
                }
 #if defined(AST_MISDN_ENHANCEMENTS)
                for (i = MAX_BCHANS + 1; i < ARRAY_LEN(stack->bc); ++i) {
-                       empty_chan_in_stack(stack, i + 1);
                        empty_bc(&stack->bc[i]);
+                       empty_chan_in_stack(stack, i + 1);
                        stack->bc[i].in_use = 0;
                }
 #endif /* defined(AST_MISDN_ENHANCEMENTS) */
@@ -1328,6 +1333,8 @@ static struct misdn_stack *stack_init(int midev, int port, int ptp)
        msg_queue_init(&stack->downqueue);
        msg_queue_init(&stack->upqueue);
 
+       pthread_mutex_init(&stack->st_lock, NULL);
+
        /* query port's requirements */
        ret = mISDN_get_stack_info(midev, port, buff, sizeof(buff));
        if (ret < 0) {
@@ -1496,6 +1503,8 @@ static void stack_destroy(struct misdn_stack *stack)
 
        if (stack->upper_id)
                mISDN_write_frame(stack->midev, buf, stack->upper_id, MGR_DELLAYER | REQUEST, 0, 0, NULL, TIMEOUT_1SEC);
+
+       pthread_mutex_destroy(&stack->st_lock);
 }
 
 
@@ -1547,14 +1556,14 @@ static struct misdn_bchannel *find_bc_by_masked_l3id(struct misdn_stack *stack,
        int i;
 
        for (i = 0; i <= stack->b_num; ++i) {
-               if ((stack->bc[i].l3_id & mask) == (l3id & mask)) {
+               if (stack->bc[i].in_use && (stack->bc[i].l3_id & mask) == (l3id & mask)) {
                        return &stack->bc[i];
                }
        }
 #if defined(AST_MISDN_ENHANCEMENTS)
        /* Search the B channel records for a REGISTER signaling link. */
        for (i = MAX_BCHANS + 1; i < ARRAY_LEN(stack->bc); ++i) {
-               if ((stack->bc[i].l3_id & mask) == (l3id & mask)) {
+               if (stack->bc[i].in_use && (stack->bc[i].l3_id & mask) == (l3id & mask)) {
                        return &stack->bc[i];
                }
        }
@@ -1568,14 +1577,14 @@ struct misdn_bchannel *find_bc_by_l3id(struct misdn_stack *stack, unsigned long
        int i;
 
        for (i = 0; i <= stack->b_num; ++i) {
-               if (stack->bc[i].l3_id == l3id) {
+               if (stack->bc[i].in_use && stack->bc[i].l3_id == l3id) {
                        return &stack->bc[i];
                }
        }
 #if defined(AST_MISDN_ENHANCEMENTS)
        /* Search the B channel records for a REGISTER signaling link. */
        for (i = MAX_BCHANS + 1; i < ARRAY_LEN(stack->bc); ++i) {
-               if (stack->bc[i].l3_id == l3id) {
+               if (stack->bc[i].in_use && stack->bc[i].l3_id == l3id) {
                        return &stack->bc[i];
                }
        }
@@ -1588,11 +1597,11 @@ static struct misdn_bchannel *find_bc_by_addr(unsigned long addr)
        struct misdn_stack *stack;
        int i;
 
-       for (stack=glob_mgr->stack_list;
-            stack;
-            stack=stack->next) {
-               for (i=0; i<=stack->b_num; i++) {
-                       if ( (stack->bc[i].addr&STACK_ID_MASK)==(addr&STACK_ID_MASK) ||  stack->bc[i].layer_id== addr ) {
+       for (stack = glob_mgr->stack_list; stack; stack = stack->next) {
+               for (i = 0; i <= stack->b_num; i++) {
+                       if (stack->bc[i].in_use
+                               && ((stack->bc[i].addr & STACK_ID_MASK) == (addr & STACK_ID_MASK)
+                                       || stack->bc[i].layer_id == addr)) {
                                return &stack->bc[i];
                        }
                }
@@ -1606,11 +1615,9 @@ static struct misdn_bchannel *find_bc_by_confid(unsigned long confid)
        struct misdn_stack *stack;
        int i;
 
-       for (stack=glob_mgr->stack_list;
-            stack;
-            stack=stack->next) {
-               for (i=0; i<=stack->b_num; i++) {
-                       if ( stack->bc[i].conf_id==confid ) {
+       for (stack = glob_mgr->stack_list; stack; stack = stack->next) {
+               for (i = 0; i <= stack->b_num; i++) {
+                       if (stack->bc[i].in_use && stack->bc[i].conf_id == confid) {
                                return &stack->bc[i];
                        }
                }
@@ -1624,10 +1631,12 @@ static struct misdn_bchannel *find_bc_by_channel(int port, int channel)
        struct misdn_stack *stack = find_stack_by_port(port);
        int i;
 
-       if (!stack) return NULL;
+       if (!stack) {
+               return NULL;
+       }
 
-       for (i=0; i<=stack->b_num; i++) {
-               if ( stack->bc[i].channel== channel ) {
+       for (i = 0; i <= stack->b_num; i++) {
+               if (stack->bc[i].in_use && stack->bc[i].channel == channel) {
                        return &stack->bc[i];
                }
        }
@@ -1814,6 +1823,7 @@ static int handle_cr ( struct misdn_stack *stack, iframe_t *frm)
 /* Empties bc if it's reserved (no SETUP out yet) */
 void misdn_lib_release(struct misdn_bchannel *bc)
 {
+       int channel;
        struct misdn_stack *stack=get_stack_by_bc(bc);
 
        if (!stack) {
@@ -1821,11 +1831,12 @@ void misdn_lib_release(struct misdn_bchannel *bc)
                return;
        }
 
-       if (bc->channel>0)
-               empty_chan_in_stack(stack,bc->channel);
-
+       channel = bc->channel;
        empty_bc(bc);
        clean_up_bc(bc);
+       if (channel > 0) {
+               empty_chan_in_stack(stack, channel);
+       }
        bc->in_use=0;
 }
 
@@ -2871,20 +2882,18 @@ static int handle_frm(msg_t *msg)
                bc->cause = tmpcause;
                bc->out_cause = tmp_out_cause;
                clean_up_bc(bc);
+               bc->in_use = 0;
 
                if (tmpcause == AST_CAUSE_REQUESTED_CHAN_UNAVAIL) {
-                       cb_log(0, stack->port, "**** Received CAUSE:%d, so not cleaning up channel %d\n", AST_CAUSE_REQUESTED_CHAN_UNAVAIL, channel);
-                       cb_log(0, stack->port, "**** This channel is now no longer available,\nplease try to restart it with 'misdn send restart <port> <channel>'\n");
-                       set_chan_in_stack(stack, channel);
-                       bc->channel = channel;
+                       cb_log(0, stack->port, "**** Received CAUSE:%d, restarting channel %d\n", AST_CAUSE_REQUESTED_CHAN_UNAVAIL, channel);
                        misdn_lib_send_restart(stack->port, channel);
-               } else if (channel > 0) {
+               }
+               if (channel > 0) {
                        empty_chan_in_stack(stack, channel);
                }
-               bc->in_use = 0;
                break;
        case EVENT_RESTART:
-               cb_log(0, stack->port, "**** Received RESTART_ACK channel:%d\n", bc->restart_channel);
+               cb_log(0, stack->port, "**** Received RESTART channel:%d\n", bc->restart_channel);
                empty_chan_in_stack(stack, bc->restart_channel);
                break;
        default:
@@ -3246,11 +3255,12 @@ struct misdn_bchannel *manager_find_bc_by_pid(int pid)
        struct misdn_stack *stack;
        int i;
 
-       for (stack=glob_mgr->stack_list;
-            stack;
-            stack=stack->next) {
-               for (i=0; i<=stack->b_num; i++)
-                       if (stack->bc[i].pid == pid) return &stack->bc[i];
+       for (stack = glob_mgr->stack_list; stack; stack = stack->next) {
+               for (i = 0; i <= stack->b_num; i++) {
+                       if (stack->bc[i].in_use && stack->bc[i].pid == pid) {
+                               return &stack->bc[i];
+                       }
+               }
        }
 
        return NULL;
@@ -3282,7 +3292,6 @@ static void prepare_bc(struct misdn_bchannel*bc, int channel)
 {
        bc->channel = channel;
        bc->channel_preselected = channel?1:0;
-       bc->in_use = 1;
        bc->need_disconnect=1;
        bc->need_release=1;
        bc->need_release_complete=1;
@@ -3296,6 +3305,8 @@ static void prepare_bc(struct misdn_bchannel*bc, int channel)
        bc->b_stid=0;
        bc->layer_id=0;
 #endif
+
+       bc->in_use = 1;
 }
 
 struct misdn_bchannel *misdn_lib_get_free_bc(int port, int channel, int inout, int dec)
@@ -3309,8 +3320,6 @@ struct misdn_bchannel *misdn_lib_get_free_bc(int port, int channel, int inout, i
                return NULL;
        }
 
-       usleep(1000);
-
        /* Find the port stack structure */
        stack = find_stack_by_port(port);
        if (!stack) {
@@ -3323,20 +3332,24 @@ struct misdn_bchannel *misdn_lib_get_free_bc(int port, int channel, int inout, i
                return NULL;
        }
 
+    pthread_mutex_lock(&stack->st_lock);
        if (channel > 0) {
                if (channel <= stack->b_num) {
                        for (i = 0; i < stack->b_num; i++) {
                                if (stack->bc[i].channel == channel) {
                                        if (test_inuse(&stack->bc[i])) {
+                                               pthread_mutex_unlock(&stack->st_lock);
                                                cb_log(0, port, "Requested channel:%d on port:%d is already in use\n", channel, port);
                                                return NULL;
                                        } else {
                                                prepare_bc(&stack->bc[i], channel);
+                                               pthread_mutex_unlock(&stack->st_lock);
                                                return &stack->bc[i];
                                        }
                                }
                        }
                } else {
+                       pthread_mutex_unlock(&stack->st_lock);
                        cb_log(0, port, "Requested channel:%d is out of bounds on port:%d\n", channel, port);
                        return NULL;
                }
@@ -3354,6 +3367,7 @@ struct misdn_bchannel *misdn_lib_get_free_bc(int port, int channel, int inout, i
 
                                prepare_bc(&stack->bc[i], channel);
                                stack->bc[i].dec = 1;
+                               pthread_mutex_unlock(&stack->st_lock);
                                return &stack->bc[i];
                        }
                }
@@ -3366,10 +3380,12 @@ struct misdn_bchannel *misdn_lib_get_free_bc(int port, int channel, int inout, i
                                }
 
                                prepare_bc(&stack->bc[i], channel);
+                               pthread_mutex_unlock(&stack->st_lock);
                                return &stack->bc[i];
                        }
                }
        }
+       pthread_mutex_unlock(&stack->st_lock);
 
        cb_log(1, port, "There is no free channel on port (%d)\n", port);
        return NULL;
@@ -3402,15 +3418,18 @@ struct misdn_bchannel *misdn_lib_get_register_bc(int port)
                return NULL;
        }
 
+    pthread_mutex_lock(&stack->st_lock);
        for (index = MAX_BCHANS + 1; index < ARRAY_LEN(stack->bc); ++index) {
                bc = &stack->bc[index];
                if (!test_inuse(bc)) {
                        prepare_bc(bc, 0);
                        bc->need_disconnect = 0;
                        bc->need_release = 0;
+                       pthread_mutex_unlock(&stack->st_lock);
                        return bc;
                }
        }
+       pthread_mutex_unlock(&stack->st_lock);
 
        cb_log(1, port, "There is no free REGISTER link on port (%d)\n", port);
        return NULL;
@@ -4116,7 +4135,7 @@ int misdn_lib_send_restart(int port, int channel)
                /* clean up chan in stack, to be sure we don't think it's
                 * in use anymore */
                for (cnt=0; cnt<=stack->b_num; cnt++) {
-                       if (stack->bc[cnt].channel == channel) {
+                       if (stack->bc[cnt].in_use && stack->bc[cnt].channel == channel) {
                                empty_bc(&stack->bc[cnt]);
                                clean_up_bc(&stack->bc[cnt]);
                                stack->bc[cnt].in_use=0;

diff --git a/channels/misdn/isdn_lib_intern.h b/channels/misdn/isdn_lib_intern.h
index 3d0fd5428ac1d8cf23859fc7c5eee34e5cc0a7b2..d811f8066b488e039cd2deecf80aa9eef9c6577f 100644 (file)
--- a/channels/misdn/isdn_lib_intern.h
+++ b/channels/misdn/isdn_lib_intern.h
@@ -67,6 +67,9 @@ struct misdn_stack {
        manager_t mgr;
        pthread_mutex_t nstlock;
 
+       /*! \brief Stack struct critical section lock. */
+       pthread_mutex_t st_lock;
+
        /*! \brief D Channel mISDN driver stack ID (Parent stack ID) */
        int d_stid;
 
@@ -134,7 +137,7 @@ struct misdn_stack {
         */
        char channels[MAX_BCHANS + 1 + MISDN_MAX_REGISTER_LINKS];
 
-       /*! \brief List of holded channels */
+       /*! \brief List of held channels */
        struct misdn_bchannel *holding;
 
        /*! \brief Next stack in the list of stacks */