Adding upstream version 3.2.1+dfsg.upstream/3.2.1+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1215 insertions, 0 deletions

diff --git a/src/lib/debug.c b/src/lib/debug.c
new file mode 100644
index 0000000..be702cf
--- /dev/null
+++ b/src/lib/debug.c
@@ -0,0 +1,1215 @@
+/*
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+/**
+ * @file debug.c
+ * @brief Various functions to aid in debugging
+ *
+ * @copyright 2013  The FreeRADIUS server project
+ * @copyright 2013  Arran Cudbard-Bell <a.cudbardb@freeradius.org>
+ */
+#include <assert.h>
+#include <freeradius-devel/libradius.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+USES_APPLE_DEPRECATED_API
+
+#if defined(HAVE_MALLOPT) && defined(HAVE_MALLOC_H)
+#  include <malloc.h>
+#endif
+
+/*
+ *	runtime backtrace functions are not POSIX but are included in
+ *	glibc, OSX >= 10.5 and various BSDs
+ */
+#ifdef HAVE_EXECINFO
+#  include <execinfo.h>
+#endif
+
+#ifdef HAVE_SYS_PRCTL_H
+#  include <sys/prctl.h>
+#endif
+
+#ifdef HAVE_SYS_PROCCTL_H
+#  include <sys/procctl.h>
+#endif
+
+#ifdef HAVE_SYS_PTRACE_H
+#  include <sys/ptrace.h>
+#  if !defined(PT_ATTACH) && defined(PTRACE_ATTACH)
+#    define PT_ATTACH PTRACE_ATTACH
+#  endif
+#  if !defined(PT_DETACH) && defined(PTRACE_DETACH)
+#    define PT_DETACH PTRACE_DETACH
+#  endif
+#endif
+
+#ifdef HAVE_SYS_RESOURCE_H
+#  include <sys/resource.h>
+#endif
+
+#ifdef HAVE_PTHREAD_H
+#  define PTHREAD_MUTEX_LOCK pthread_mutex_lock
+#  define PTHREAD_MUTEX_UNLOCK pthread_mutex_unlock
+#else
+#  define PTHREAD_MUTEX_LOCK(_x)
+#  define PTHREAD_MUTEX_UNLOCK(_x)
+#endif
+
+#ifdef HAVE_EXECINFO
+#  ifndef MAX_BT_FRAMES
+#    define MAX_BT_FRAMES 128
+#  endif
+#  ifndef MAX_BT_CBUFF
+#    define MAX_BT_CBUFF  1048576			//!< Should be a power of 2
+#  endif
+
+#  ifdef HAVE_PTHREAD_H
+static pthread_mutex_t fr_debug_init = PTHREAD_MUTEX_INITIALIZER;
+#  endif
+
+typedef struct fr_bt_info {
+	void 		*obj;				//!< Memory address of the block of allocated memory.
+	void		*frames[MAX_BT_FRAMES];		//!< Backtrace frame data
+	int		count;				//!< Number of frames stored
+} fr_bt_info_t;
+
+struct fr_bt_marker {
+	void 		*obj;				//!< Pointer to the parent object, this is our needle
+							//!< when we iterate over the contents of the circular buffer.
+	fr_cbuff_t 	*cbuff;				//!< Where we temporarily store the backtraces
+};
+#endif
+
+static char panic_action[512];				//!< The command to execute when panicking.
+static fr_fault_cb_t panic_cb = NULL;			//!< Callback to execute whilst panicking, before the
+							//!< panic_action.
+
+static bool dump_core;					//!< Whether we should drop a core on fatal signals.
+
+static int fr_fault_log_fd = STDERR_FILENO;		//!< Where to write debug output.
+
+fr_debug_state_t fr_debug_state = DEBUG_STATE_UNKNOWN;	//!< Whether we're attached to by a debugger.
+
+#ifdef HAVE_SYS_RESOURCE_H
+static struct rlimit core_limits;
+#endif
+
+static TALLOC_CTX *talloc_null_ctx;
+static TALLOC_CTX *talloc_autofree_ctx;
+
+/*
+ * On BSD systems, ptrace(PT_DETACH) uses a third argument for
+ * resume address, with the magic value (void *)1 to resume where
+ * process stopped. Specifying NULL there leads to a crash because
+ * process resumes at address 0.
+ */
+#ifdef HAVE_SYS_PTRACE_H
+#  ifdef __linux__
+#    define _PTRACE(_x, _y) ptrace(_x, _y, NULL, NULL)
+#    define _PTRACE_DETACH(_x) ptrace(PT_DETACH, _x, NULL, NULL)
+#  else
+#    define _PTRACE(_x, _y) ptrace(_x, _y, NULL, 0)
+#    define _PTRACE_DETACH(_x) ptrace(PT_DETACH, _x, (void *)1, 0)
+#  endif
+
+#  ifdef HAVE_CAPABILITY_H
+#    include <sys/capability.h>
+#  endif
+
+/** Determine if we're running under a debugger by attempting to attach using pattach
+ *
+ * @return 0 if we're not, 1 if we are, -1 if we can't tell because of an error,
+ *	-2 if we can't tell because we don't have the CAP_SYS_PTRACE capability.
+ */
+static int fr_get_debug_state(void)
+{
+	int pid;
+
+	int from_child[2] = {-1, -1};
+
+#ifdef HAVE_CAPABILITY_H
+	cap_flag_value_t value;
+	cap_t current;
+
+	/*
+	 *  If we're running under linux, we first need to check if we have
+	 *  permission to to ptrace. We do that using the capabilities
+	 *  functions.
+	 */
+	current = cap_get_proc();
+	if (!current) {
+		fr_strerror_printf("Failed getting process capabilities: %s", fr_syserror(errno));
+		return DEBUG_STATE_UNKNOWN;
+	}
+
+	if (cap_get_flag(current, CAP_SYS_PTRACE, CAP_PERMITTED, &value) < 0) {
+		fr_strerror_printf("Failed getting permitted ptrace capability state: %s",
+				   fr_syserror(errno));
+		cap_free(current);
+		return DEBUG_STATE_UNKNOWN;
+	}
+
+	if ((value == CAP_SET) && (cap_get_flag(current, CAP_SYS_PTRACE, CAP_EFFECTIVE, &value) < 0)) {
+		fr_strerror_printf("Failed getting effective ptrace capability state: %s",
+				   fr_syserror(errno));
+		cap_free(current);
+		return DEBUG_STATE_UNKNOWN;
+	}
+
+	/*
+	 *  We don't have permission to ptrace, so this test will always fail.
+	 */
+	if (value == CAP_CLEAR) {
+		fr_strerror_printf("ptrace capability not set.  If debugger detection is required run as root or: "
+				   "setcap cap_sys_ptrace+ep <path_to_radiusd>");
+		cap_free(current);
+		return DEBUG_STATE_UNKNOWN_NO_PTRACE_CAP;
+	}
+	cap_free(current);
+#endif
+
+	if (pipe(from_child) < 0) {
+		fr_strerror_printf("Error opening internal pipe: %s", fr_syserror(errno));
+		return DEBUG_STATE_UNKNOWN;
+	}
+
+	pid = fork();
+	if (pid == -1) {
+		fr_strerror_printf("Error forking: %s", fr_syserror(errno));
+		return DEBUG_STATE_UNKNOWN;
+	}
+
+	/* Child */
+	if (pid == 0) {
+		int8_t ret = DEBUG_STATE_NOT_ATTACHED;
+		int ppid = getppid();
+
+		/* Close parent's side */
+		close(from_child[0]);
+
+		/*
+		 *	FreeBSD is extremely picky about the order of operations here
+		 *	we need to attach, wait *then* write whilst the parent is still
+		 *	suspended, then detach, continuing the process.
+		 *
+		 *	If we don't do it in that order the read in the parent triggers
+		 *	a SIGKILL.
+		 */
+		if (_PTRACE(PT_ATTACH, ppid) == 0) {
+			/* Wait for the parent to stop */
+			waitpid(ppid, NULL, 0);
+
+			/* Tell the parent what happened */
+			if (write(from_child[1], &ret, sizeof(ret)) < 0) {
+				fprintf(stderr, "Writing ptrace status to parent failed: %s", fr_syserror(errno));
+			}
+
+			/* Detach */
+			_PTRACE_DETACH(ppid);
+			exit(0);
+		}
+
+		ret = DEBUG_STATE_ATTACHED;
+		/* Tell the parent what happened */
+		if (write(from_child[1], &ret, sizeof(ret)) < 0) {
+			fprintf(stderr, "Writing ptrace status to parent failed: %s", fr_syserror(errno));
+		}
+
+		exit(0);
+	/* Parent */
+	} else {
+		int8_t ret = DEBUG_STATE_UNKNOWN;
+
+		/*
+		 *	The child writes errno (reason) if pattach failed else 0.
+		 *
+		 *	This read may be interrupted by pattach,
+		 *	which is why we need the loop.
+		 */
+		while ((read(from_child[0], &ret, sizeof(ret)) < 0) && (errno == EINTR));
+
+		/* Close the pipes here (if we did it above, it might race with pattach) */
+		close(from_child[1]);
+		close(from_child[0]);
+
+		/* Collect the status of the child */
+		waitpid(pid, NULL, 0);
+
+		return ret;
+	}
+}
+#elif defined(HAVE_SYS_PROCCTL_H)
+static int fr_get_debug_state(void)
+{
+	int status;
+
+	if (procctl(P_PID, getpid(), PROC_TRACE_STATUS, &status) == -1) {
+		fr_strerror_printf("Cannot get dumpable flag: procctl(PROC_TRACE_STATUS) failed: %s", fr_syserror(errno));
+		return DEBUG_STATE_UNKNOWN;
+	}
+
+	/*
+	 *	As FreeBSD docs say about "PROC_TRACE_STATUS":
+	 *
+	 *	Returns the current tracing status for the specified process in the
+	 *	integer variable pointed to by data.  If tracing is disabled, data
+	 *	is set to -1.  If tracing is enabled, but no debugger is attached by
+	 *	the ptrace(2) syscall, data is set to 0.  If a debugger is attached,
+	 *	data is set to the pid of the debugger process.
+	 */
+	if (status <= 0) return DEBUG_STATE_NOT_ATTACHED;
+
+	return DEBUG_STATE_ATTACHED;
+}
+#else
+static int fr_get_debug_state(void)
+{
+	fr_strerror_printf("PTRACE not available");
+
+	return DEBUG_STATE_UNKNOWN_NO_PTRACE;
+}
+#endif
+
+/** Should be run before using setuid or setgid to get useful results
+ *
+ * @note sets the fr_debug_state global.
+ */
+void fr_store_debug_state(void)
+{
+	fr_debug_state = fr_get_debug_state();
+
+#ifndef NDEBUG
+	/*
+	 *  There are many reasons why this might happen with
+	 *  a vanilla install, so we don't want to spam users
+	 *  with messages they won't understand and may not
+	 *  want to resolve.
+	 */
+	if (fr_debug_state < 0) fprintf(stderr, "Getting debug state failed: %s\n", fr_strerror());
+#endif
+}
+
+/** Return current value of debug_state
+ *
+ * @param state to translate into a humanly readable value.
+ * @return humanly readable version of debug state.
+ */
+char const *fr_debug_state_to_msg(fr_debug_state_t state)
+{
+	switch (state) {
+	case DEBUG_STATE_UNKNOWN_NO_PTRACE:
+		return "Debug state unknown (ptrace functionality not available)";
+
+	case DEBUG_STATE_UNKNOWN_NO_PTRACE_CAP:
+		return "Debug state unknown (cap_sys_ptrace capability not set)";
+
+	case DEBUG_STATE_UNKNOWN:
+		return "Debug state unknown";
+
+	case DEBUG_STATE_ATTACHED:
+		return "Found debugger attached";
+
+	case DEBUG_STATE_NOT_ATTACHED:
+		return "Debugger not attached";
+	}
+
+	return "<INVALID>";
+}
+
+/** Break in debugger (if were running under a debugger)
+ *
+ * If the server is running under a debugger this will raise a
+ * SIGTRAP which will pause the running process.
+ *
+ * If the server is not running under debugger then this will do nothing.
+ */
+void fr_debug_break(bool always)
+{
+	if (always) raise(SIGTRAP);
+
+	if (fr_debug_state < 0) fr_debug_state = fr_get_debug_state();
+	if (fr_debug_state == DEBUG_STATE_ATTACHED) {
+		fprintf(stderr, "Debugger detected, raising SIGTRAP\n");
+		fflush(stderr);
+
+		raise(SIGTRAP);
+	}
+}
+
+#ifdef HAVE_EXECINFO
+/** Print backtrace entry for a given object
+ *
+ * @param cbuff to search in.
+ * @param obj pointer to original object
+ */
+void backtrace_print(fr_cbuff_t *cbuff, void *obj)
+{
+	fr_bt_info_t *p;
+	bool found = false;
+
+	while ((p = fr_cbuff_rp_next(cbuff, NULL))) {
+		if ((p->obj == obj) || !obj) {
+			found = true;
+
+			fprintf(stderr, "Stacktrace for: %p\n", p->obj);
+			backtrace_symbols_fd(p->frames, p->count, STDERR_FILENO);
+		}
+	};
+
+	if (!found) {
+		fprintf(stderr, "No backtrace available for %p", obj);
+	}
+}
+
+/** Generate a backtrace for an object
+ *
+ * If this is the first entry being inserted
+ */
+int fr_backtrace_do(fr_bt_marker_t *marker)
+{
+	fr_bt_info_t *bt;
+
+	if (!fr_assert(marker->obj) || !fr_assert(marker->cbuff)) return -1;
+
+	bt = talloc_zero(NULL, fr_bt_info_t);
+	if (!bt) return -1;
+
+	bt->obj = marker->obj;
+	bt->count = backtrace(bt->frames, MAX_BT_FRAMES);
+
+	fr_cbuff_rp_insert(marker->cbuff, bt);
+
+	return 0;
+}
+
+/** Inserts a backtrace marker into the provided context
+ *
+ * Allows for maximum laziness and will initialise a circular buffer if one has not already been created.
+ *
+ * Code augmentation should look something like:
+@verbatim
+	// Create a static cbuffer pointer, the first call to backtrace_attach will initialise it
+	static fr_cbuff_t *my_obj_bt;
+
+	my_obj_t *alloc_my_obj(TALLOC_CTX *ctx) {
+		my_obj_t *this;
+
+		this = talloc(ctx, my_obj_t);
+
+		// Attach backtrace marker to object
+		backtrace_attach(&my_obj_bt, this);
+
+		return this;
+	}
+@endverbatim
+ *
+ * Then, later when a double free occurs:
+@verbatim
+	(gdb) call backtrace_print(&my_obj_bt, <pointer to double freed memory>)
+@endverbatim
+ *
+ * which should print a limited backtrace to stderr. Note, this backtrace will not include any argument
+ * values, but should at least show the code path taken.
+ *
+ * @param cbuff this should be a pointer to a static *fr_cbuff.
+ * @param obj we want to generate a backtrace for.
+ */
+fr_bt_marker_t *fr_backtrace_attach(fr_cbuff_t **cbuff, TALLOC_CTX *obj)
+{
+	fr_bt_marker_t *marker;
+
+	if (*cbuff == NULL) {
+		PTHREAD_MUTEX_LOCK(&fr_debug_init);
+		/* Check again now we hold the mutex - eww*/
+		if (*cbuff == NULL) *cbuff = fr_cbuff_alloc(NULL, MAX_BT_CBUFF, true);
+		PTHREAD_MUTEX_UNLOCK(&fr_debug_init);
+	}
+
+	marker = talloc(obj, fr_bt_marker_t);
+	if (!marker) {
+		return NULL;
+	}
+
+	marker->obj = (void *) obj;
+	marker->cbuff = *cbuff;
+
+	fprintf(stderr, "Backtrace attached to %s %p\n", talloc_get_name(obj), obj);
+	/*
+	 *	Generate the backtrace for memory allocation
+	 */
+	fr_backtrace_do(marker);
+	talloc_set_destructor(marker, fr_backtrace_do);
+
+	return marker;
+}
+#else
+void backtrace_print(UNUSED fr_cbuff_t *cbuff, UNUSED void *obj)
+{
+	fprintf(stderr, "Server built without fr_backtrace_* support, requires execinfo.h and possibly -lexecinfo\n");
+}
+fr_bt_marker_t *fr_backtrace_attach(UNUSED fr_cbuff_t **cbuff, UNUSED TALLOC_CTX *obj)
+{
+	fprintf(stderr, "Server built without fr_backtrace_* support, requires execinfo.h and possibly -lexecinfo\n");
+	abort();
+}
+#endif /* ifdef HAVE_EXECINFO */
+
+static int _panic_on_free(UNUSED char *foo)
+{
+	fr_fault(SIGABRT);
+	return -1;	/* this should make the free fail */
+}
+
+/** Insert memory into the context of another talloc memory chunk which
+ * causes a panic when freed.
+ *
+ * @param ctx TALLOC_CTX to monitor for frees.
+ */
+void fr_panic_on_free(TALLOC_CTX *ctx)
+{
+	char *ptr;
+
+	ptr = talloc(ctx, char);
+	talloc_set_destructor(ptr, _panic_on_free);
+}
+
+/** Set the dumpable flag, also controls whether processes can PATTACH
+ *
+ * @param dumpable whether we should allow core dumping
+ */
+#if defined(HAVE_SYS_PRCTL_H) && defined(PR_SET_DUMPABLE)
+static int fr_set_dumpable_flag(bool dumpable)
+{
+	if (prctl(PR_SET_DUMPABLE, dumpable ? 1 : 0) < 0) {
+		fr_strerror_printf("Cannot re-enable core dumps: prctl(PR_SET_DUMPABLE) failed: %s",
+				   fr_syserror(errno));
+		return -1;
+	}
+
+	return 0;
+}
+#elif defined(HAVE_SYS_PROCCTL_H)
+static int fr_set_dumpable_flag(bool dumpable)
+{
+	int mode = dumpable ? PROC_TRACE_CTL_ENABLE : PROC_TRACE_CTL_DISABLE;
+
+	if (procctl(P_PID, getpid(), PROC_TRACE_CTL, &mode) == -1) {
+		fr_strerror_printf("Cannot re-enable core dumps: procctl(PROC_TRACE_CTL) failed: %s",
+				   fr_syserror(errno));
+		return -1;
+	}
+
+	return 0;
+}
+#else
+static int fr_set_dumpable_flag(UNUSED bool dumpable)
+{
+	fr_strerror_printf("Changing value of PR_DUMPABLE not supported on this system");
+	return -2;
+}
+#endif
+
+/** Get the processes dumpable flag
+ *
+ */
+#if defined(HAVE_SYS_PRCTL_H) && defined(PR_GET_DUMPABLE)
+static int fr_get_dumpable_flag(void)
+{
+	int ret;
+
+	ret = prctl(PR_GET_DUMPABLE);
+	if (ret < 0) {
+		fr_strerror_printf("Cannot get dumpable flag: %s", fr_syserror(errno));
+		return -1;
+	}
+
+	/*
+	 *  Linux is crazy and prctl sometimes returns 2 for disabled
+	 */
+	if (ret != 1) return 0;
+	return 1;
+}
+#elif defined(HAVE_SYS_PROCCTL_H)
+static int fr_get_dumpable_flag(void)
+{
+	int status;
+
+	if (procctl(P_PID, getpid(), PROC_TRACE_CTL, &status) == -1) {
+		fr_strerror_printf("Cannot get dumpable flag: procctl(PROC_TRACE_CTL) failed: %s", fr_syserror(errno));
+		return -1;
+	}
+
+	/*
+	 *	There are a few different kinds of disabled, but only
+	 *	one ENABLE.
+	 */
+	if (status != PROC_TRACE_CTL_ENABLE) return 0;
+
+	return 1;
+}
+#else
+static int fr_get_dumpable_flag(void)
+{
+	fr_strerror_printf("Getting value of PR_DUMPABLE not supported on this system");
+	return -2;
+}
+#endif
+
+
+/** Get the current maximum for core files
+ *
+ * Do this before anything else so as to ensure it's properly initialized.
+ */
+int fr_set_dumpable_init(void)
+{
+#ifdef HAVE_SYS_RESOURCE_H
+	if (getrlimit(RLIMIT_CORE, &core_limits) < 0) {
+		fr_strerror_printf("Failed to get current core limit:  %s", fr_syserror(errno));
+		return -1;
+	}
+#endif
+	return 0;
+}
+
+/** Enable or disable core dumps
+ *
+ * @param allow_core_dumps whether to enable or disable core dumps.
+ */
+int fr_set_dumpable(bool allow_core_dumps)
+{
+	dump_core = allow_core_dumps;
+	/*
+	 *	If configured, turn core dumps off.
+	 */
+	if (!allow_core_dumps) {
+#ifdef HAVE_SYS_RESOURCE_H
+		struct rlimit no_core;
+
+		no_core.rlim_cur = 0;
+		no_core.rlim_max = core_limits.rlim_max;
+
+		if (setrlimit(RLIMIT_CORE, &no_core) < 0) {
+			fr_strerror_printf("Failed disabling core dumps: %s", fr_syserror(errno));
+
+			return -1;
+		}
+#endif
+		return 0;
+	}
+
+	if (fr_set_dumpable_flag(true) < 0) return -1;
+
+	/*
+	 *	Reset the core dump limits to their original value.
+	 */
+#ifdef HAVE_SYS_RESOURCE_H
+	if (setrlimit(RLIMIT_CORE, &core_limits) < 0) {
+		fr_strerror_printf("Cannot update core dump limit: %s", fr_syserror(errno));
+
+		return -1;
+	}
+#endif
+	return 0;
+}
+
+/** Reset dumpable state to previously configured value
+ *
+ * Needed after suid up/down
+ *
+ * @return 0 on success, else -1 on failure.
+ */
+int fr_reset_dumpable(void)
+{
+	return fr_set_dumpable(dump_core);
+}
+
+/** Check to see if panic_action file is world writeable
+ *
+ * @return 0 if file is OK, else -1.
+ */
+static int fr_fault_check_permissions(void)
+{
+	char const *p, *q;
+	size_t len;
+	char filename[256];
+	struct stat statbuf;
+
+	/*
+	 *	Try and guess which part of the command is the binary, and check to see if
+	 *	it's world writeable, to try and save the admin from their own stupidity.
+	 *
+	 *	@fixme we should do this properly and take into account single and double
+	 *	quotes.
+	 */
+	if ((q = strchr(panic_action, ' '))) {
+		/*
+		 *	need to use a static buffer, because mallocing memory in a signal handler
+		 *	is a bad idea and can result in deadlock.
+		 */
+		len = snprintf(filename, sizeof(filename), "%.*s", (int)(q - panic_action), panic_action);
+		if (is_truncated(len, sizeof(filename))) {
+			fr_strerror_printf("Failed writing panic_action to temporary buffer (truncated)");
+			return -1;
+		}
+		p = filename;
+	} else {
+		p = panic_action;
+	}
+
+	if (stat(p, &statbuf) == 0) {
+#ifdef S_IWOTH
+		if ((statbuf.st_mode & S_IWOTH) != 0) {
+			fr_strerror_printf("panic_action file \"%s\" is globally writable", p);
+			return -1;
+		}
+#endif
+	}
+
+	return 0;
+}
+
+/** Prints a simple backtrace (if execinfo is available) and calls panic_action if set.
+ *
+ * @param sig caught
+ */
+NEVER_RETURNS void fr_fault(int sig)
+{
+	char cmd[sizeof(panic_action) + 20];
+	char *out = cmd;
+	size_t left = sizeof(cmd), ret;
+
+	char const *p = panic_action;
+	char const *q;
+
+	int code;
+
+	/*
+	 *	If a debugger is attached, we don't want to run the panic action,
+	 *	as it may interfere with the operation of the debugger.
+	 *	If something calls us directly we just raise the signal and let
+	 *	the debugger handle it how it wants.
+	 */
+	if (fr_debug_state == DEBUG_STATE_ATTACHED) {
+		FR_FAULT_LOG("RAISING SIGNAL: %s", strsignal(sig));
+		raise(sig);
+		goto finish;
+	}
+
+	/*
+	 *	Makes the backtraces slightly cleaner
+	 */
+	memset(cmd, 0, sizeof(cmd));
+
+	FR_FAULT_LOG("CAUGHT SIGNAL: %s", strsignal(sig));
+
+	/*
+	 *	Check for administrator sanity.
+	 */
+	if (fr_fault_check_permissions() < 0) {
+		FR_FAULT_LOG("Refusing to execute panic action: %s", fr_strerror());
+		goto finish;
+	}
+
+	/*
+	 *	Run the callback if one was registered
+	 */
+	if (panic_cb && (panic_cb(sig) < 0)) goto finish;
+
+	/*
+	 *	Produce a simple backtrace - They're very basic but at least give us an
+	 *	idea of the area of the code we hit the issue in.
+	 *
+	 *	See below in fr_fault_setup() and
+	 *	https://sourceware.org/bugzilla/show_bug.cgi?id=16159
+	 *	for why we only print backtraces in debug builds if we're using GLIBC.
+	 */
+#if defined(HAVE_EXECINFO) && (!defined(NDEBUG) || !defined(__GNUC__))
+	if (fr_fault_log_fd >= 0) {
+		size_t frame_count;
+		void *stack[MAX_BT_FRAMES];
+
+		frame_count = backtrace(stack, MAX_BT_FRAMES);
+
+		FR_FAULT_LOG("Backtrace of last %zu frames:", frame_count);
+
+		backtrace_symbols_fd(stack, frame_count, fr_fault_log_fd);
+	}
+#endif
+
+	/* No panic action set... */
+	if (panic_action[0] == '\0') {
+		FR_FAULT_LOG("No panic action set");
+		goto finish;
+	}
+
+	/* Substitute %p for the current PID (useful for attaching a debugger) */
+	while ((q = strstr(p, "%p"))) {
+		out += ret = snprintf(out, left, "%.*s%d", (int) (q - p), p, (int) getpid());
+		if (left <= ret) {
+		oob:
+			FR_FAULT_LOG("Panic action too long");
+			fr_exit_now(1);
+		}
+		left -= ret;
+		p = q + 2;
+	}
+	if (strlen(p) >= left) goto oob;
+	strlcpy(out, p, left);
+
+	{
+		bool disable = false;
+
+		FR_FAULT_LOG("Calling: %s", cmd);
+
+		/*
+		 *	Here we temporarily enable the dumpable flag so if GBD or LLDB
+		 *	is called in the panic_action, they can pattach to the running
+		 *	process.
+		 */
+		if (fr_get_dumpable_flag() == 0) {
+			if ((fr_set_dumpable_flag(true) < 0) || !fr_get_dumpable_flag()) {
+				FR_FAULT_LOG("Failed setting dumpable flag, pattach may not work: %s", fr_strerror());
+			} else {
+				disable = true;
+			}
+			FR_FAULT_LOG("Temporarily setting PR_DUMPABLE to 1");
+		}
+
+		code = system(cmd);
+
+		/*
+		 *	We only want to error out here, if dumpable was originally disabled
+		 *	and we managed to change the value to enabled, but failed
+		 *	setting it back to disabled.
+		 */
+		if (disable) {
+			FR_FAULT_LOG("Resetting PR_DUMPABLE to 0");
+			if (fr_set_dumpable_flag(false) < 0) {
+				FR_FAULT_LOG("Failed resetting dumpable flag to off: %s", fr_strerror());
+				FR_FAULT_LOG("Exiting due to insecure process state");
+				fr_exit_now(1);
+			}
+		}
+
+		FR_FAULT_LOG("Panic action exited with %i", code);
+
+		fr_exit_now(code);
+	}
+
+
+finish:
+	/*
+	 *	(Re-)Raise the signal, so that if we're running under
+	 *	a debugger, the debugger can break when it receives
+	 *	the signal.
+	 */
+	fr_unset_signal(sig);	/* Make sure we don't get into a loop */
+
+	raise(sig);
+
+	fr_exit_now(1);		/* Function marked as noreturn */
+}
+
+/** Callback executed on fatal talloc error
+ *
+ * This is the simple version which mostly behaves the same way as the default
+ * one, and will not call panic_action.
+ *
+ * @param reason string provided by talloc.
+ */
+static void _fr_talloc_fault_simple(char const *reason) CC_HINT(noreturn);
+static void _fr_talloc_fault_simple(char const *reason)
+{
+	FR_FAULT_LOG("talloc abort: %s\n", reason);
+
+#if defined(HAVE_EXECINFO) && (!defined(NDEBUG) || !defined(__GNUC__))
+	if (fr_fault_log_fd >= 0) {
+		size_t frame_count;
+		void *stack[MAX_BT_FRAMES];
+
+		frame_count = backtrace(stack, MAX_BT_FRAMES);
+		FR_FAULT_LOG("Backtrace of last %zu frames:", frame_count);
+		backtrace_symbols_fd(stack, frame_count, fr_fault_log_fd);
+	}
+#endif
+	abort();
+}
+
+/** Callback executed on fatal talloc error
+ *
+ * Translates a talloc abort into a fr_fault call.
+ * Mostly to work around issues with some debuggers not being able to
+ * attach after a SIGABRT has been raised.
+ *
+ * @param reason string provided by talloc.
+ */
+static void _fr_talloc_fault(char const *reason) CC_HINT(noreturn);
+static void _fr_talloc_fault(char const *reason)
+{
+	FR_FAULT_LOG("talloc abort: %s", reason);
+#ifdef SIGABRT
+	fr_fault(SIGABRT);
+#endif
+	fr_exit_now(1);
+}
+
+/** Wrapper to pass talloc log output to our fr_fault_log function
+ *
+ */
+static void _fr_talloc_log(char const *msg)
+{
+	fr_fault_log("%s\n", msg);
+}
+
+/** Generate a talloc memory report for a context and print to stderr/stdout
+ *
+ * @param ctx to generate a report for, may be NULL in which case the root context is used.
+ */
+int fr_log_talloc_report(TALLOC_CTX *ctx)
+{
+#define TALLOC_REPORT_MAX_DEPTH 20
+
+	FILE *log;
+	int fd;
+
+	fd = dup(fr_fault_log_fd);
+	if (fd < 0) {
+		fr_strerror_printf("Couldn't write memory report, failed to dup log fd: %s", fr_syserror(errno));
+		return -1;
+	}
+	log = fdopen(fd, "w");
+	if (!log) {
+		close(fd);
+		fr_strerror_printf("Couldn't write memory report, fdopen failed: %s", fr_syserror(errno));
+		return -1;
+	}
+
+	if (!ctx) {
+		fprintf(log, "Current state of talloced memory:\n");
+		talloc_report_full(talloc_null_ctx, log);
+	} else {
+		int i;
+
+		fprintf(log, "Talloc chunk lineage:\n");
+		fprintf(log, "%p (%s)", ctx, talloc_get_name(ctx));
+
+		i = 0;
+		while ((i < TALLOC_REPORT_MAX_DEPTH) && (ctx = talloc_parent(ctx))) {
+			fprintf(log, " < %p (%s)", ctx, talloc_get_name(ctx));
+			i++;
+		}
+		fprintf(log, "\n");
+
+		i = 0;
+		do {
+			fprintf(log, "Talloc context level %i:\n", i++);
+			talloc_report_full(ctx, log);
+		} while ((ctx = talloc_parent(ctx)) &&
+			 (i < TALLOC_REPORT_MAX_DEPTH) &&
+			 (talloc_parent(ctx) != talloc_autofree_ctx) &&	/* Stop before we hit the autofree ctx */
+			 (talloc_parent(ctx) != talloc_null_ctx));  	/* Stop before we hit NULL ctx */
+	}
+
+	fclose(log);
+
+	return 0;
+}
+
+
+static int _fr_disable_null_tracking(UNUSED bool *p)
+{
+	talloc_disable_null_tracking();
+	return 0;
+}
+
+/** Register talloc fault handlers
+ *
+ * Just register the fault handlers we need to make talloc
+ * produce useful debugging output.
+ */
+void fr_talloc_fault_setup(void)
+{
+	talloc_set_log_fn(_fr_talloc_log);
+	talloc_set_abort_fn(_fr_talloc_fault_simple);
+}
+
+/** Registers signal handlers to execute panic_action on fatal signal
+ *
+ * May be called multiple time to change the panic_action/program.
+ *
+ * @param cmd to execute on fault. If present %p will be substituted
+ *        for the parent PID before the command is executed, and %e
+ *        will be substituted for the currently running program.
+ * @param program Name of program currently executing (argv[0]).
+ * @return 0 on success -1 on failure.
+ */
+int fr_fault_setup(char const *cmd, char const *program)
+{
+	static bool setup = false;
+
+	char *out = panic_action;
+	size_t left = sizeof(panic_action);
+
+	char const *p = cmd;
+	char const *q;
+
+	if (cmd) {
+		size_t ret;
+
+		/* Substitute %e for the current program */
+		while ((q = strstr(p, "%e"))) {
+			out += ret = snprintf(out, left, "%.*s%s", (int) (q - p), p, program ? program : "");
+			if (left <= ret) {
+			oob:
+				fr_strerror_printf("Panic action too long");
+				return -1;
+			}
+			left -= ret;
+			p = q + 2;
+		}
+		if (strlen(p) >= left) goto oob;
+		strlcpy(out, p, left);
+	} else {
+		*panic_action = '\0';
+	}
+
+	/*
+	 *	Check for administrator sanity.
+	 */
+	if (fr_fault_check_permissions() < 0) return -1;
+
+	/* Unsure what the side effects of changing the signal handler mid execution might be */
+	if (!setup) {
+		char *env;
+		fr_debug_state_t debug_state;
+
+		/*
+		 *  Installing signal handlers interferes with some debugging
+		 *  operations.  Give the developer control over whether the
+		 *  signal handlers are installed or not.
+		 */
+		env = getenv("DEBUG");
+		if (!env || (strcmp(env, "no") == 0)) {
+			debug_state = DEBUG_STATE_NOT_ATTACHED;
+		} else if (!strcmp(env, "auto") || !strcmp(env, "yes")) {
+			/*
+			 *  Figure out if we were started under a debugger
+			 */
+			if (fr_debug_state < 0) fr_debug_state = fr_get_debug_state();
+			debug_state = fr_debug_state;
+		} else {
+			debug_state = DEBUG_STATE_ATTACHED;
+		}
+
+		talloc_set_log_fn(_fr_talloc_log);
+
+		/*
+		 *  These signals can't be properly dealt with in the debugger
+		 *  if we set our own signal handlers.
+		 */
+		switch (debug_state) {
+		default:
+#ifndef NDEBUG
+			FR_FAULT_LOG("Debugger check failed: %s", fr_strerror());
+			FR_FAULT_LOG("Signal processing in debuggers may not work as expected");
+#endif
+			/* FALL-THROUGH */
+
+		case DEBUG_STATE_NOT_ATTACHED:
+#ifdef SIGABRT
+			if (fr_set_signal(SIGABRT, fr_fault) < 0) return -1;
+
+			/*
+			 *  Use this instead of abort so we get a
+			 *  full backtrace with broken versions of LLDB
+			 */
+			talloc_set_abort_fn(_fr_talloc_fault);
+#endif
+#ifdef SIGILL
+			if (fr_set_signal(SIGILL, fr_fault) < 0) return -1;
+#endif
+#ifdef SIGFPE
+			if (fr_set_signal(SIGFPE, fr_fault) < 0) return -1;
+#endif
+#ifdef SIGSEGV
+			if (fr_set_signal(SIGSEGV, fr_fault) < 0) return -1;
+#endif
+			break;
+
+		case DEBUG_STATE_ATTACHED:
+			break;
+		}
+
+		/*
+		 *  Needed for memory reports
+		 */
+		{
+			TALLOC_CTX *tmp;
+			bool *marker;
+
+			tmp = talloc(NULL, bool);
+			talloc_null_ctx = talloc_parent(tmp);
+			talloc_free(tmp);
+
+			/*
+			 *  Disable null tracking on exit, else valgrind complains
+			 */
+			talloc_autofree_ctx = talloc_autofree_context();
+			marker = talloc(talloc_autofree_ctx, bool);
+			talloc_set_destructor(marker, _fr_disable_null_tracking);
+		}
+
+#if defined(HAVE_MALLOPT) && !defined(NDEBUG)
+		/*
+		 *  If were using glibc malloc > 2.4 this scribbles over
+		 *  uninitialised and freed memory, to make memory issues easier
+		 *  to track down.
+		 */
+		if (!getenv("TALLOC_FREE_FILL")) mallopt(M_PERTURB, 0x42);
+		mallopt(M_CHECK_ACTION, 3);
+#endif
+
+#if defined(HAVE_EXECINFO) && defined(__GNUC__) && !defined(NDEBUG)
+	       /*
+		*  We need to pre-load lgcc_s, else we can get into a deadlock
+		*  in fr_fault, as backtrace() attempts to dlopen it.
+		*
+		*  Apparently there's a performance impact of loading lgcc_s,
+		*  so only do it if this is a debug build.
+		*
+		*  See: https://sourceware.org/bugzilla/show_bug.cgi?id=16159
+		*/
+		{
+			void *stack[10];
+
+			backtrace(stack, 10);
+		}
+#endif
+	}
+	setup = true;
+
+	return 0;
+}
+
+/** Set a callback to be called before fr_fault()
+ *
+ * @param func to execute. If callback returns < 0
+ *	fr_fault will exit before running panic_action code.
+ */
+void fr_fault_set_cb(fr_fault_cb_t func)
+{
+	panic_cb = func;
+}
+
+/** Log output to the fr_fault_log_fd
+ *
+ * We used to support a user defined callback, which was set to a radlog
+ * function. Unfortunately, when logging to syslog, syslog would malloc memory
+ * which would result in a deadlock if fr_fault was triggered from within
+ * a malloc call.
+ *
+ * Now we just write directly to the FD.
+ */
+void fr_fault_log(char const *msg, ...)
+{
+	va_list ap;
+
+	if (fr_fault_log_fd < 0) return;
+
+	va_start(ap, msg);
+	vdprintf(fr_fault_log_fd, msg, ap);
+	va_end(ap);
+}
+
+/** Set a file descriptor to log memory reports to.
+ *
+ * @param fd to write output to.
+ */
+void fr_fault_set_log_fd(int fd)
+{
+	fr_fault_log_fd = fd;
+}
+
+/** A soft assertion which triggers the fault handler in debug builds
+ *
+ * @param file the assertion failed in.
+ * @param line of the assertion in the file.
+ * @param expr that was evaluated.
+ * @param cond Result of evaluating the expression.
+ * @return the value of cond.
+ */
+bool fr_assert_cond(char const *file, int line, char const *expr, bool cond)
+{
+	if (!cond) {
+		FR_FAULT_LOG("SOFT ASSERT FAILED %s[%u]: %s", file, line, expr);
+#if !defined(NDEBUG)
+		fr_fault(SIGABRT);
+#endif
+		return false;
+	}
+
+	return cond;
+}
+
+/** Exit possibly printing a message about why we're exiting.
+ *
+ * @note Use the fr_exit(status) macro instead of calling this function directly.
+ *
+ * @param file where fr_exit() was called.
+ * @param line where fr_exit() was called.
+ * @param status we're exiting with.
+ */
+void NEVER_RETURNS _fr_exit(char const *file, int line, int status)
+{
+#ifndef NDEBUG
+	char const *error = fr_strerror();
+
+	if (error && *error && (status != 0)) {
+		FR_FAULT_LOG("EXIT(%i) CALLED %s[%u].  Last error was: %s", status, file, line, error);
+	} else {
+		FR_FAULT_LOG("EXIT(%i) CALLED %s[%u]", status, file, line);
+	}
+#endif
+	fr_debug_break(false);	/* If running under GDB we'll break here */
+
+	exit(status);
+}
+
+/** Exit possibly printing a message about why we're exiting.
+ *
+ * @note Use the fr_exit_now(status) macro instead of calling this function directly.
+ *
+ * @param file where fr_exit_now() was called.
+ * @param line where fr_exit_now() was called.
+ * @param status we're exiting with.
+ */
+void NEVER_RETURNS _fr_exit_now(char const *file, int line, int status)
+{
+#ifndef NDEBUG
+	char const *error = fr_strerror();
+
+	if (error && (status != 0)) {
+		FR_FAULT_LOG("_EXIT(%i) CALLED %s[%u].  Last error was: %s", status, file, line, error);
+	} else {
+		FR_FAULT_LOG("_EXIT(%i) CALLED %s[%u]", status, file, line);
+	}
+#endif
+	fr_debug_break(false);	/* If running under GDB we'll break here */
+
+	_exit(status);
+}