issue #5712

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@7086 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/ChangeLog b/ChangeLog
index b4af88a..d0e90ea 100755 (executable)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 2005-11-11  Kevin P. Fleming  <kpfleming@digium.com>
 
+       * channels/chan_sip.c (thread_safe_rand): ensure that threads don't get the same random number (issue #5712)
+
        * apps/app_voicemail.c (forward_message): correct bugs in message forwarding (issue #5718)
        (copy_message): use correct path for locking (issue #5704)
 

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 399e101..3c7aef5 100755 (executable)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -384,6 +384,7 @@ static int global_mwitime = DEFAULT_MWITIME;        /*!< Time between MWI checks for pe
 static int usecnt =0;
 AST_MUTEX_DEFINE_STATIC(usecnt_lock);
 
+AST_MUTEX_DEFINE_STATIC(rand_lock);
 
 /*! \brief Protect the interface list (of sip_pvt's) */
 AST_MUTEX_DEFINE_STATIC(iflock);
@@ -943,6 +944,24 @@ static const struct ast_channel_tech sip_tech = {
        .send_text = sip_sendtext,
 };
 
+/*!
+  \brief Thread-safe random number generator
+  \return a random number
+
+  This function uses a mutex lock to guarantee that no
+  two threads will receive the same random number.
+ */
+static force_inline int thread_safe_rand(void)
+{
+       int val;
+
+       ast_mutex_lock(&rand_lock);
+       val = rand();
+       ast_mutex_unlock(&rand_lock);
+       
+       return val;
+}
+
 /*! \brief  find_sip_method: Find SIP method from header
  * Strictly speaking, SIP methods are case SENSITIVE, but we don't check 
  * following Jon Postel's rule: Be gentle in what you accept, strict with what you send */
@@ -2721,7 +2740,7 @@ static struct ast_channel *sip_new(struct sip_pvt *i, int state, char *title)
        fmt = ast_best_codec(tmp->nativeformats);
 
        if (title)
-               snprintf(tmp->name, sizeof(tmp->name), "SIP/%s-%04x", title, rand() & 0xffff);
+               snprintf(tmp->name, sizeof(tmp->name), "SIP/%s-%04x", title, thread_safe_rand() & 0xffff);
        else if (strchr(i->fromdomain,':'))
                snprintf(tmp->name, sizeof(tmp->name), "SIP/%s-%08x", strchr(i->fromdomain,':')+1, (int)(long)(i));
        else
@@ -2974,7 +2993,7 @@ static void build_callid(char *callid, int len, struct in_addr ourip, char *from
        int x;
        char iabuf[INET_ADDRSTRLEN];
        for (x=0; x<4; x++) {
-               val = rand();
+               val = thread_safe_rand();
                res = snprintf(callid, len, "%08x", val);
                len -= res;
                callid += res;
@@ -2988,7 +3007,7 @@ static void build_callid(char *callid, int len, struct in_addr ourip, char *from
 
 static void make_our_tag(char *tagbuf, size_t len)
 {
-       snprintf(tagbuf, len, "as%08x", rand());
+       snprintf(tagbuf, len, "as%08x", thread_safe_rand());
 }
 
 /*! \brief  sip_alloc: Allocate SIP_PVT structure and set defaults ---*/
@@ -3021,7 +3040,7 @@ static struct sip_pvt *sip_alloc(char *callid, struct sockaddr_in *sin, int useg
                memcpy(&p->ourip, &__ourip, sizeof(p->ourip));
        }
 
-       p->branch = rand();     
+       p->branch = thread_safe_rand(); 
        make_our_tag(p->tag, sizeof(p->tag));
        /* Start with 101 instead of 1 */
        p->ocseq = 101;
@@ -4009,7 +4028,7 @@ static int reqprep(struct sip_request *req, struct sip_pvt *p, int sipmethod, in
        }
        
        if (newbranch) {
-               p->branch ^= rand();
+               p->branch ^= thread_safe_rand();
                build_via(p, p->via, sizeof(p->via));
        }
 
@@ -4826,7 +4845,7 @@ static int transmit_invite(struct sip_pvt *p, int sipmethod, int sdp, int init)
        req.method = sipmethod;
        if (init) {
                /* Bump branch even on initial requests */
-               p->branch ^= rand();
+               p->branch ^= thread_safe_rand();
                build_via(p, p->via, sizeof(p->via));
                if (init > 1)
                        initreqprep(&req, p, sipmethod);
@@ -5400,7 +5419,7 @@ static int transmit_register(struct sip_registry *r, int sipmethod, char *auth,
                snprintf(addr, sizeof(addr), "sip:%s", r->hostname);
        ast_copy_string(p->uri, addr, sizeof(p->uri));
 
-       p->branch ^= rand();
+       p->branch ^= thread_safe_rand();
 
        memset(&req, 0, sizeof(req));
        init_req(&req, sipmethod, addr);
@@ -5670,7 +5689,7 @@ static void reg_source_db(struct sip_peer *peer)
                /* SIP isn't up yet, so schedule a poke only, pretty soon */
                if (peer->pokeexpire > -1)
                        ast_sched_del(sched, peer->pokeexpire);
-               peer->pokeexpire = ast_sched_add(sched, rand() % 5000 + 1, sip_poke_peer_s, peer);
+               peer->pokeexpire = ast_sched_add(sched, thread_safe_rand() % 5000 + 1, sip_poke_peer_s, peer);
        } else
                sip_poke_peer(peer);
        if (peer->expire > -1)
@@ -6131,7 +6150,7 @@ static int check_auth(struct sip_pvt *p, struct sip_request *req, char *randdata
                        res = 1;
                }
        } else if (ast_strlen_zero(randdata) || ast_strlen_zero(authtoken)) {
-               snprintf(randdata, randlen, "%08x", rand());
+               snprintf(randdata, randlen, "%08x", thread_safe_rand());
                transmit_response_with_auth(p, response, req, randdata, reliable, respheader, 0);
                /* Schedule auto destroy in 15 seconds */
                sip_scheddestroy(p, 15000);
@@ -6247,7 +6266,7 @@ static int check_auth(struct sip_pvt *p, struct sip_request *req, char *randdata
 
                if (wrongnonce) {
 
-                       snprintf(randdata, randlen, "%08x", rand());
+                       snprintf(randdata, randlen, "%08x", thread_safe_rand());
                        if (ua_hash && !strncasecmp(ua_hash, resp_hash, strlen(resp_hash))) {
                                if (sipdebug)
                                        ast_log(LOG_NOTICE, "stale nonce received from '%s'\n", get_header(req, "To"));
@@ -8962,7 +8981,7 @@ static int build_reply_digest(struct sip_pvt *p, int method, char* digest, int d
        else
                snprintf(uri, sizeof(uri), "sip:%s@%s",p->username, ast_inet_ntoa(iabuf, sizeof(iabuf), p->sa.sin_addr));
 
-       snprintf(cnonce, sizeof(cnonce), "%08x", rand());
+       snprintf(cnonce, sizeof(cnonce), "%08x", thread_safe_rand());
 
        /* Check if we have separate auth credentials */
        if ((auth = find_realm_authentication(authl, p->realm))) {