sysmocom
/
asterisk
11
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

chan_sip: Prevent deadlock when issuing "sip show channels" 

sip_show_channels locks the dialogs container first then locks each
sip_pvt so it can spit out the details.  The rest of sip dialog
processing locks the sip_pvt first then locks the dialogs container
if it needs to.  Both lock in the order they need but deadlocks can
result.  To fix, sip_show_channels and sip_show_channelstats have
been converted to use an iterator rather than ao2_callback.  This way
the container is locked only while getting the next entry and is
unlocked when the callback is called.

ASTERISK-23013 #close

Change-Id: Id9980419909e811f89484950ed46ef117b9eb990
This commit is contained in:
George Joseph 2016-07-21 08:05:03 -06:00 committed by Richard Mudgett
parent 194d0f606b
commit 1b4922466b
1 changed files with 18 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
channels/chan_sip.c
View File

@ -21321,15 +21321,13 @@ static char *sip_unregister(struct ast_cli_entry *e, int cmd, struct ast_cli_arg
}
/*! \brief Callback for show_chanstats */
static int show_chanstats_cb(void *__cur, void *__arg, int flags)
static int show_chanstats_cb(struct sip_pvt *cur, struct __show_chan_arg *arg)
{
#define FORMAT2 "%-15.15s %-11.11s %-8.8s %-10.10s %-10.10s ( %%) %-6.6s %-10.10s %-10.10s ( %%) %-6.6s\n"
#define FORMAT "%-15.15s %-11.11s %-8.8s %-10.10u%-1.1s %-10.10u (%5.2f%%) %-6.4lf %-10.10u%-1.1s %-10.10u (%5.2f%%) %-6.4lf\n"
struct sip_pvt *cur = __cur;
struct ast_rtp_instance_stats stats;
char durbuf[10];
struct ast_channel *c;
struct __show_chan_arg *arg = __arg;
int fd = arg->fd;
sip_pvt_lock(cur);
@ -21389,6 +21387,8 @@ static int show_chanstats_cb(void *__cur, void *__arg, int flags)
static char *sip_show_channelstats(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
struct __show_chan_arg arg = { .fd = a->fd, .numchans = 0 };
struct sip_pvt *cur;
struct ao2_iterator i;
switch (cmd) {
case CLI_INIT:
@ -21406,8 +21406,14 @@ static char *sip_show_channelstats(struct ast_cli_entry *e, int cmd, struct ast_
return CLI_SHOWUSAGE;
ast_cli(a->fd, FORMAT2, "Peer", "Call ID", "Duration", "Recv: Pack", "Lost", "Jitter", "Send: Pack", "Lost", "Jitter");
/* iterate on the container and invoke the callback on each item */
ao2_t_callback(dialogs, OBJ_NODATA, show_chanstats_cb, &arg, "callback to sip show chanstats");
i = ao2_iterator_init(dialogs, 0);
for (; (cur = ao2_iterator_next(&i)); ao2_ref(cur, -1)) {
show_chanstats_cb(cur, &arg);
}
ao2_iterator_destroy(&i);
ast_cli(a->fd, "%d active SIP channel%s\n", arg.numchans, (arg.numchans != 1) ? "s" : "");
return CLI_SUCCESS;
}
@ -21727,10 +21733,8 @@ static const struct cfsubscription_types *find_subscription_type(enum subscripti
#define FORMAT "%-15.15s %-15.15s %-15.15s %-15.15s %-3.3s %-3.3s %-15.15s %-10.10s %-10.10s\n"
/*! \brief callback for show channel|subscription */
static int show_channels_cb(void *__cur, void *__arg, int flags)
static int show_channels_cb(struct sip_pvt *cur, struct __show_chan_arg *arg)
{
struct sip_pvt *cur = __cur;
struct __show_chan_arg *arg = __arg;
const struct ast_sockaddr *dst;
sip_pvt_lock(cur);
@ -21782,7 +21786,8 @@ static int show_channels_cb(void *__cur, void *__arg, int flags)
static char *sip_show_channels(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
struct __show_chan_arg arg = { .fd = a->fd, .numchans = 0 };
struct sip_pvt *cur;
struct ao2_iterator i;
if (cmd == CLI_INIT) {
e->command = "sip show {channels|subscriptions}";
@ -21804,7 +21809,11 @@ static char *sip_show_channels(struct ast_cli_entry *e, int cmd, struct ast_cli_
ast_cli(arg.fd, FORMAT3, "Peer", "User", "Call ID", "Extension", "Last state", "Type", "Mailbox", "Expiry");
/* iterate on the container and invoke the callback on each item */
ao2_t_callback(dialogs, OBJ_NODATA, show_channels_cb, &arg, "callback to show channels");
i = ao2_iterator_init(dialogs, 0);
for (; (cur = ao2_iterator_next(&i)); ao2_ref(cur, -1)) {
show_channels_cb(cur, &arg);
}
ao2_iterator_destroy(&i);
/* print summary information */
ast_cli(arg.fd, "%d active SIP %s%s\n", arg.numchans,