fault: get fault.c ready for use by s4

this moves the s3 specific dumpcore code into source3/lib/dumpcore.c,
and uses a function pointer to setup which smb_panic call to use

2 files changed, 74 insertions, 299 deletions

diff --git a/lib/util/fault.c b/lib/util/fault.c
index 2ffd5dbd6d..086dc33545 100644
--- a/lib/util/fault.c
+++ b/lib/util/fault.c
@@ -19,6 +19,8 @@
 */
 
 #include "includes.h"
+#include "system/filesys.h"
+#include "version.h"
 
 #ifdef HAVE_SYS_SYSCTL_H
 #include <sys/sysctl.h>
@@ -29,7 +31,32 @@
 #include <sys/prctl.h>
 #endif
 
-static char *corepath;
+static struct {
+	bool disabled;
+	smb_panic_handler_t panic_handler;
+} fault_state;
+
+
+/*******************************************************************
+setup variables used for fault handling
+********************************************************************/
+void fault_configure(smb_panic_handler_t panic_handler)
+{
+	fault_state.panic_handler = panic_handler;
+}
+
+
+/**
+   disable setting up fault handlers
+   This is used for the bind9 dlz module, as we
+   don't want a Samba module in bind9 to override the bind
+   fault handling
+**/
+_PUBLIC_ void fault_setup_disable(void)
+{
+	fault_state.disabled = true;
+}
+
 
 /*******************************************************************
 report a fault
@@ -43,9 +70,8 @@ static void fault_report(int sig)
 	counter++;
 
 	DEBUGSEP(0);
-	DEBUG(0,("INTERNAL ERROR: Signal %d in pid %d (%s)",sig,(int)sys_getpid(),samba_version_string()));
-	DEBUG(0,("\nPlease read the Trouble-Shooting section of the Samba3-HOWTO\n"));
-	DEBUG(0,("\nFrom: http://www.samba.org/samba/docs/Samba3-HOWTO.pdf\n"));
+	DEBUG(0,("INTERNAL ERROR: Signal %d in pid %d (%s)",sig,(int)sys_getpid(),SAMBA_VERSION_STRING));
+	DEBUG(0,("\nPlease read the Trouble-Shooting section of the Samba HOWTO\n"));
 	DEBUGSEP(0);
 
 	smb_panic("internal error");
@@ -67,6 +93,9 @@ setup our fault handlers
 ********************************************************************/
 void fault_setup(void)
 {
+	if (fault_state.disabled) {
+		return;
+	}
 #ifdef SIGSEGV
 	CatchSignal(SIGSEGV, sig_fault);
 #endif
@@ -78,303 +107,48 @@ void fault_setup(void)
 #endif
 }
 
-/**
- * Build up the default corepath as "<logbase>/cores/<progname>"
- */
-static char *get_default_corepath(const char *logbase, const char *progname)
-{
-	char *tmp_corepath;
-
-	/* Setup core dir in logbase. */
-	tmp_corepath = talloc_asprintf(NULL, "%s/cores", logbase);
-	if (!tmp_corepath)
-		return NULL;
-
-	if ((mkdir(tmp_corepath, 0700) == -1) && errno != EEXIST)
-		goto err_out;
-
-	if (chmod(tmp_corepath, 0700) == -1)
-		goto err_out;
-
-	talloc_free(tmp_corepath);
-
-	/* Setup progname-specific core subdir */
-	tmp_corepath = talloc_asprintf(NULL, "%s/cores/%s", logbase, progname);
-	if (!tmp_corepath)
-		return NULL;
-
-	if (mkdir(tmp_corepath, 0700) == -1 && errno != EEXIST)
-		goto err_out;
+_PUBLIC_ const char *panic_action = NULL;
 
-	if (chown(tmp_corepath, getuid(), getgid()) == -1)
-		goto err_out;
-
-	if (chmod(tmp_corepath, 0700) == -1)
-		goto err_out;
-
-	return tmp_corepath;
-
- err_out:
-	talloc_free(tmp_corepath);
-	return NULL;
-}
-
-/**
- * Get the FreeBSD corepath.
- *
- * On FreeBSD the current working directory is ignored when creating a core
- * file.  Instead the core directory is controlled via sysctl.  This consults
- * the value of "kern.corefile" so the correct corepath can be printed out
- * before dump_core() calls abort.
- */
-#if (defined(FREEBSD) && defined(HAVE_SYSCTLBYNAME))
-static char *get_freebsd_corepath(void)
+/*
+   default smb_panic() implementation
+*/
+static void smb_panic_default(const char *why)
 {
-	char *tmp_corepath = NULL;
-	char *end = NULL;
-	size_t len = 128;
-	int ret;
-
-	/* Loop with increasing sizes so we don't allocate too much. */
-	do {
-		if (len > 1024)  {
-			goto err_out;
-		}
-
-		tmp_corepath = (char *)talloc_realloc(NULL, tmp_corepath,
-						      char, len);
-		if (!tmp_corepath) {
-			return NULL;
-		}
+	int result;
+
+	if (panic_action && *panic_action) {
+		char pidstr[20];
+		char cmdstring[200];
+		safe_strcpy(cmdstring, panic_action, sizeof(cmdstring)-1);
+		snprintf(pidstr, sizeof(pidstr), "%d", (int) getpid());
+		all_string_sub(cmdstring, "%PID%", pidstr, sizeof(cmdstring));
+		DEBUG(0, ("smb_panic(): calling panic action [%s]\n", cmdstring));
+		result = system(cmdstring);
+
+		if (result == -1)
+			DEBUG(0, ("smb_panic(): fork failed in panic action: %s\n",
+				  strerror(errno)));
+		else
+			DEBUG(0, ("smb_panic(): action returned status %d\n",
+				  WEXITSTATUS(result)));
+	}
+	DEBUG(0,("PANIC: %s\n", why));
 
-		ret = sysctlbyname("kern.corefile", tmp_corepath, &len, NULL,
-				   0);
-		if (ret == -1) {
-			if (errno != ENOMEM) {
-				DEBUG(0, ("sysctlbyname failed getting "
-					  "kern.corefile %s\n",
-					  strerror(errno)));
-				goto err_out;
-			}
-
-			/* Not a large enough array, try a bigger one. */
-			len = len << 1;
-		}
-	} while (ret == -1);
-
-	/* Strip off the common filename expansion */
-	if ((end = strrchr_m(tmp_corepath, '/'))) {
-		*end = '\0';
-	}
-
-	return tmp_corepath;
-
- err_out:
-	if (tmp_corepath) {
-		talloc_free(tmp_corepath);
-	}
-	return NULL;
-}
+#ifdef SIGABRT
+	CatchSignal(SIGABRT, SIG_DFL);
 #endif
-
-#if defined(HAVE_SYS_KERNEL_PROC_CORE_PATTERN)
-
-/**
- * Get the Linux corepath.
- *
- * On Linux the contents of /proc/sys/kernel/core_pattern indicates the
- * location of the core path.
- */
-static char *get_linux_corepath(void)
-{
-	char *end;
-	int fd;
-	char *result;
-
-	fd = open("/proc/sys/kernel/core_pattern", O_RDONLY, 0);
-	if (fd == -1) {
-		return NULL;
-	}
-
-	result = afdgets(fd, NULL, 0);
-	close(fd);
-
-	if (result == NULL) {
-		return NULL;
-	}
-
-	if (result[0] != '/') {
-		/*
-		 * No absolute path, use the default (cwd)
-		 */
-		TALLOC_FREE(result);
-		return NULL;
-	}
-	/* Strip off the common filename expansion */
-
-	end = strrchr_m(result, '/');
-
-	if ((end != result) /* this would be the only / */
-	    && (end != NULL)) {
-		*end = '\0';
-	}
-	return result;
+	abort();
 }
-#endif
 
 
 /**
- * Try getting system-specific corepath if one exists.
- *
- * If the system doesn't define a corepath, then the default is used.
- */
-static char *get_corepath(const char *logbase, const char *progname)
-{
-#if (defined(FREEBSD) && defined(HAVE_SYSCTLBYNAME))
-	char *tmp_corepath = NULL;
-	tmp_corepath = get_freebsd_corepath();
-
-	/* If this has been set correctly, we're done. */
-	if (tmp_corepath) {
-		return tmp_corepath;
-	}
-#endif
-
-#if defined(HAVE_SYS_KERNEL_PROC_CORE_PATTERN)
-	char *tmp_corepath = NULL;
-	tmp_corepath = get_linux_corepath();
-
-	/* If this has been set correctly, we're done. */
-	if (tmp_corepath) {
-		return tmp_corepath;
-	}
-#endif
-
-	/* Fall back to the default. */
-	return get_default_corepath(logbase, progname);
-}
-
-/*******************************************************************
-make all the preparations to safely dump a core file
-********************************************************************/
-
-void dump_core_setup(const char *progname)
-{
-	char *logbase = NULL;
-	char *end = NULL;
-
-	if (lp_logfile() && *lp_logfile()) {
-		if (asprintf(&logbase, "%s", lp_logfile()) < 0) {
-			return;
-		}
-		if ((end = strrchr_m(logbase, '/'))) {
-			*end = '\0';
-		}
-	} else {
-		/* We will end up here if the log file is given on the command
-		 * line by the -l option but the "log file" option is not set
-		 * in smb.conf.
-		 */
-		if (asprintf(&logbase, "%s", get_dyn_LOGFILEBASE()) < 0) {
-			return;
-		}
-	}
-
-	SMB_ASSERT(progname != NULL);
-
-	corepath = get_corepath(logbase, progname);
-	if (!corepath) {
-		DEBUG(0, ("Unable to setup corepath for %s: %s\n", progname,
-			  strerror(errno)));
-		goto out;
-	}
-
-
-#ifdef HAVE_GETRLIMIT
-#ifdef RLIMIT_CORE
-	{
-		struct rlimit rlp;
-		getrlimit(RLIMIT_CORE, &rlp);
-		rlp.rlim_cur = MAX(16*1024*1024,rlp.rlim_cur);
-		setrlimit(RLIMIT_CORE, &rlp);
-		getrlimit(RLIMIT_CORE, &rlp);
-		DEBUG(3,("Maximum core file size limits now %d(soft) %d(hard)\n",
-			 (int)rlp.rlim_cur,(int)rlp.rlim_max));
-	}
-#endif
-#endif
-
-	/* FIXME: if we have a core-plus-pid facility, configurably set
-	 * this up here.
-	 */
- out:
-	SAFE_FREE(logbase);
-}
-
- void dump_core(void)
+   Something really nasty happened - panic !
+**/
+_PUBLIC_ void smb_panic(const char *why)
 {
-	static bool called;
-
-	if (called) {
-		DEBUG(0, ("dump_core() called recursive\n"));
-		exit(1);
-	}
-	called = true;
-
-	/* Note that even if core dumping has been disabled, we still set up
-	 * the core path. This is to handle the case where core dumping is
-	 * turned on in smb.conf and the relevant daemon is not restarted.
-	 */
-	if (!lp_enable_core_files()) {
-		DEBUG(0, ("Exiting on internal error (core file administratively disabled)\n"));
-		exit(1);
-	}
-
-#if DUMP_CORE
-	/* If we're running as non root we might not be able to dump the core
-	 * file to the corepath.  There must not be an unbecome_root() before
-	 * we call abort(). */
-	if (geteuid() != sec_initial_uid()) {
-		become_root();
-	}
-
-	if (corepath == NULL) {
-		DEBUG(0, ("Can not dump core: corepath not set up\n"));
-		exit(1);
-	}
-
-	if (*corepath != '\0') {
-		/* The chdir might fail if we dump core before we finish
-		 * processing the config file.
-		 */
-		if (chdir(corepath) != 0) {
-			DEBUG(0, ("unable to change to %s\n", corepath));
-			DEBUGADD(0, ("refusing to dump core\n"));
-			exit(1);
-		}
-
-		DEBUG(0,("dumping core in %s\n", corepath));
+	if (fault_state.panic_handler) {
+		fault_state.panic_handler(why);
+		_exit(1);
 	}
-
-	umask(~(0700));
-	dbgflush();
-
-#if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
-	/* On Linux we lose the ability to dump core when we change our user
-	 * ID. We know how to dump core safely, so let's make sure we have our
-	 * dumpable flag set.
-	 */
-	prctl(PR_SET_DUMPABLE, 1);
-#endif
-
-	/* Ensure we don't have a signal handler for abort. */
-#ifdef SIGABRT
-	CatchSignal(SIGABRT, SIG_DFL);
-#endif
-
-	abort();
-
-#else /* DUMP_CORE */
-	exit(1);
-#endif /* DUMP_CORE */
+	smb_panic_default(why);
 }
diff --git a/lib/util/util.h b/lib/util/util.h
index 78071ad3ca..b143e4e991 100644
--- a/lib/util/util.h
+++ b/lib/util/util.h
@@ -73,13 +73,14 @@ _PUBLIC_ void call_backtrace(void);
 **/
 _PUBLIC_ _NORETURN_ void smb_panic(const char *why);
 
-#if _SAMBA_BUILD_ == 4
-/**
-setup our fault handlers
-**/
-_PUBLIC_ void fault_setup(const char *pname);
+typedef void (*smb_panic_handler_t)(const char *why);
+
+_PUBLIC_ void fault_configure(smb_panic_handler_t panic_handler);
+_PUBLIC_ void fault_setup(void);
 _PUBLIC_ void fault_setup_disable(void);
-#endif
+_PUBLIC_ void dump_core_setup(const char *progname, const char *logfile);
+_PUBLIC_ void smb_panic(const char *reason);
+
 
 /**
   register a fault handler.