[asterisk-commits] rmudgett: branch 1.8 r320796 - in /branches/1.8: include/asterisk/ main/
SVN commits to the Asterisk project
asterisk-commits at lists.digium.com
Wed May 25 11:23:23 CDT 2011
Author: rmudgett
Date: Wed May 25 11:23:11 2011
New Revision: 320796
URL: http://svnview.digium.com/svn/asterisk?view=rev&rev=320796
Log:
Give zombies a safe channel driver to use.
Recent crashes from zombie channels suggests that they need a safe home to
goto. When a masquerade happens, the physical part of the zombie channel
is hungup. The hangup normally sets the channel private pointer to NULL.
If someone then blindly does a callback to the channel driver, a crash is
likely because the private pointer is NULL.
The masquerade now sets the channel technology of zombie channels to the
kill channel driver.
Related to the following issues:
(issue #19116)
(issue #19310)
Review: https://reviewboard.asterisk.org/r/1224/
Modified:
branches/1.8/include/asterisk/channel.h
branches/1.8/main/channel.c
branches/1.8/main/features.c
Modified: branches/1.8/include/asterisk/channel.h
URL: http://svnview.digium.com/svn/asterisk/branches/1.8/include/asterisk/channel.h?view=diff&rev=320796&r1=320795&r2=320796
==============================================================================
--- branches/1.8/include/asterisk/channel.h (original)
+++ branches/1.8/include/asterisk/channel.h Wed May 25 11:23:11 2011
@@ -628,6 +628,9 @@
*/
int (* cc_callback)(struct ast_channel *inbound, const char *dest, ast_cc_callback_fn callback);
};
+
+/*! Kill the channel channel driver technology descriptor. */
+extern const struct ast_channel_tech ast_kill_tech;
struct ast_epoll_data;
Modified: branches/1.8/main/channel.c
URL: http://svnview.digium.com/svn/asterisk/branches/1.8/main/channel.c?view=diff&rev=320796&r1=320795&r2=320796
==============================================================================
--- branches/1.8/main/channel.c (original)
+++ branches/1.8/main/channel.c Wed May 25 11:23:11 2011
@@ -610,6 +610,56 @@
static struct ast_cli_entry cli_channel[] = {
AST_CLI_DEFINE(handle_cli_core_show_channeltypes, "List available channel types"),
AST_CLI_DEFINE(handle_cli_core_show_channeltype, "Give more details on that channel type")
+};
+
+static struct ast_frame *kill_read(struct ast_channel *chan)
+{
+ /* Hangup channel. */
+ return NULL;
+}
+
+static struct ast_frame *kill_exception(struct ast_channel *chan)
+{
+ /* Hangup channel. */
+ return NULL;
+}
+
+static int kill_write(struct ast_channel *chan, struct ast_frame *frame)
+{
+ /* Hangup channel. */
+ return -1;
+}
+
+static int kill_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
+{
+ /* No problem fixing up the channel. */
+ return 0;
+}
+
+static int kill_hangup(struct ast_channel *chan)
+{
+ chan->tech_pvt = NULL;
+ return 0;
+}
+
+/*!
+ * \brief Kill the channel channel driver technology descriptor.
+ *
+ * \details
+ * The purpose of this channel technology is to encourage the
+ * channel to hangup as quickly as possible.
+ *
+ * \note Used by DTMF atxfer and zombie channels.
+ */
+const struct ast_channel_tech ast_kill_tech = {
+ .type = "Kill",
+ .description = "Kill channel (should not see this)",
+ .capabilities = -1,
+ .read = kill_read,
+ .exception = kill_exception,
+ .write = kill_write,
+ .fixup = kill_fixup,
+ .hangup = kill_hangup,
};
#ifdef CHANNEL_TRACE
@@ -6415,6 +6465,12 @@
goto done;
}
+ /*
+ * We just hung up the physical side of the channel. Set the
+ * new zombie to use the kill channel driver for safety.
+ */
+ clonechan->tech = &ast_kill_tech;
+
/* Mangle the name of the clone channel */
snprintf(zombn, sizeof(zombn), "%s<ZOMBIE>", orig); /* quick, hide the brains! */
__ast_change_name_nolink(clonechan, zombn);
Modified: branches/1.8/main/features.c
URL: http://svnview.digium.com/svn/asterisk/branches/1.8/main/features.c?view=diff&rev=320796&r1=320795&r2=320796
==============================================================================
--- branches/1.8/main/features.c (original)
+++ branches/1.8/main/features.c Wed May 25 11:23:11 2011
@@ -470,58 +470,15 @@
};
#if defined(ATXFER_NULL_TECH)
-static struct ast_frame *null_read(struct ast_channel *chan)
-{
- /* Hangup channel. */
- return NULL;
-}
-
-static struct ast_frame *null_exception(struct ast_channel *chan)
-{
- /* Hangup channel. */
- return NULL;
-}
-
-static int null_write(struct ast_channel *chan, struct ast_frame *frame)
-{
- /* Hangup channel. */
- return -1;
-}
-
-static int null_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
-{
- /* No problem fixing up the channel. */
- return 0;
-}
-
-static int null_hangup(struct ast_channel *chan)
-{
- chan->tech_pvt = NULL;
- return 0;
-}
-
-static const struct ast_channel_tech null_tech = {
- .type = "NULL",
- .description = "NULL channel driver for atxfer",
- .capabilities = -1,
- .read = null_read,
- .exception = null_exception,
- .write = null_write,
- .fixup = null_fixup,
- .hangup = null_hangup,
-};
-#endif /* defined(ATXFER_NULL_TECH) */
-
-#if defined(ATXFER_NULL_TECH)
/*!
* \internal
- * \brief Set the channel technology to the NULL technology.
+ * \brief Set the channel technology to the kill technology.
*
* \param chan Channel to change technology.
*
* \return Nothing
*/
-static void set_null_chan_tech(struct ast_channel *chan)
+static void set_kill_chan_tech(struct ast_channel *chan)
{
int idx;
@@ -538,8 +495,8 @@
chan->tech_pvt = NULL;
}
- /* Install the NULL technology and wake up anyone waiting on it. */
- chan->tech = &null_tech;
+ /* Install the kill technology and wake up anyone waiting on it. */
+ chan->tech = &ast_kill_tech;
for (idx = 0; idx < AST_MAX_FDS; ++idx) {
switch (idx) {
case AST_ALERT_FD:
@@ -3115,7 +3072,7 @@
* Get rid of caller's physical technology so it is free for
* other calls.
*/
- set_null_chan_tech(caller);
+ set_kill_chan_tech(caller);
#endif /* defined(ATXFER_NULL_TECH) */
} else {
/* caller is not hungup so monitor it. */
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