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

9 files changed, 342 insertions, 11 deletions

diff --git a/source3/Makefile.in b/source3/Makefile.in
index 7ba8332eb0..065f0cbad7 100644
--- a/source3/Makefile.in
+++ b/source3/Makefile.in
@@ -443,7 +443,7 @@ LIB_OBJ = $(LIBSAMBAUTIL_OBJ) $(UTIL_OBJ) $(CRYPTO_OBJ) \
 	  lib/addrchange.o \
 	  $(TDB_LIB_OBJ) \
 	  $(VERSION_OBJ) lib/charcnv.o ../lib/util/debug.o ../lib/util/debug_s3.o ../lib/util/fault.o \
-	  lib/interface.o lib/pidfile.o \
+	  lib/interface.o lib/pidfile.o lib/dumpcore.o \
 	  lib/system.o lib/sendfile.o lib/recvfile.o lib/time.o \
 	  lib/username.o \
 	  ../libds/common/flag_mapping.o \
diff --git a/source3/include/proto.h b/source3/include/proto.h
index b5b35a4623..bb9241c893 100644
--- a/source3/include/proto.h
+++ b/source3/include/proto.h
@@ -515,10 +515,6 @@ void display_set_stderr(void);
 NTSTATUS map_nt_error_from_unix(int unix_error);
 int map_errno_from_nt_status(NTSTATUS status);
 
-/* The following definitions come from lib/fault.c  */
-void fault_setup(void);
-void dump_core_setup(const char *progname);
-
 /* The following definitions come from lib/file_id.c  */
 
 struct file_id vfs_file_id_from_sbuf(connection_struct *conn, const SMB_STRUCT_STAT *sbuf);
@@ -1095,7 +1091,7 @@ const char *uidtoname(uid_t uid);
 char *gidtoname(gid_t gid);
 uid_t nametouid(const char *name);
 gid_t nametogid(const char *name);
-void smb_panic(const char *const why);
+void smb_panic_s3(const char *why);
 void log_stack_trace(void);
 const char *readdirname(SMB_STRUCT_DIR *p);
 bool is_in_path(const char *name, name_compare_entry *namelist, bool case_sensitive);
diff --git a/source3/lib/dumpcore.c b/source3/lib/dumpcore.c
new file mode 100644
index 0000000000..8a1c43a72f
--- /dev/null
+++ b/source3/lib/dumpcore.c
@@ -0,0 +1,332 @@
+/*
+   Unix SMB/CIFS implementation.
+   Samba utility functions
+
+   Copyright (C) Andrew Tridgell 1992-2011
+
+   based on old fault.c code, which had:
+
+   Copyright (C) Jeremy Allison 2001-2007
+   Copyright (C) Simo Sorce 2001
+   Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003
+   Copyright (C) James Peach 2006
+
+   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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+
+static char *corepath;
+
+/**
+ * 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;
+
+	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)
+{
+	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;
+		}
+
+		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;
+}
+#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;
+}
+#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, const char *logfile)
+{
+	char *logbase = NULL;
+	char *end = NULL;
+
+	if (logfile && *logfile) {
+		if (asprintf(&logbase, "%s", 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)
+{
+	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));
+	}
+
+	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 */
+}
diff --git a/source3/lib/util.c b/source3/lib/util.c
index b6128feaf6..79b10fda5e 100644
--- a/source3/lib/util.c
+++ b/source3/lib/util.c
@@ -1344,7 +1344,7 @@ gid_t nametogid(const char *name)
  Something really nasty happened - panic !
 ********************************************************************/
 
-void smb_panic(const char *const why)
+void smb_panic_s3(const char *why)
 {
 	char *cmd;
 	int result;
diff --git a/source3/nmbd/nmbd.c b/source3/nmbd/nmbd.c
index 1735c90576..2aa896476f 100644
--- a/source3/nmbd/nmbd.c
+++ b/source3/nmbd/nmbd.c
@@ -812,7 +812,7 @@ static bool open_sockets(bool isdaemon, int port)
 	}
 	
 	fault_setup();
-	dump_core_setup("nmbd");
+	dump_core_setup("nmbd", lp_logfile());
 	
 	/* POSIX demands that signals are inherited. If the invoking process has
 	 * these signals masked, we will have problems, as we won't receive them. */
diff --git a/source3/param/loadparm.c b/source3/param/loadparm.c
index a82d21cdb1..ba3cd3c6c5 100644
--- a/source3/param/loadparm.c
+++ b/source3/param/loadparm.c
@@ -9541,6 +9541,8 @@ static bool lp_load_ex(const char *pszFname,
 
 	init_iconv();
 
+	fault_configure(smb_panic_s3);
+
 	bAllowIncludeRegistry = true;
 
 	return (bRetval);
diff --git a/source3/smbd/server.c b/source3/smbd/server.c
index 2c09dd26c5..37c97049b8 100644
--- a/source3/smbd/server.c
+++ b/source3/smbd/server.c
@@ -987,7 +987,7 @@ extern void build_options(bool screen);
 	gain_root_group_privilege();
 
 	fault_setup();
-	dump_core_setup("smbd");
+	dump_core_setup("smbd", lp_logfile());
 
 	/* we are never interested in SIGPIPE */
 	BlockSignals(True,SIGPIPE);
diff --git a/source3/winbindd/winbindd.c b/source3/winbindd/winbindd.c
index 99e98ac2b0..47d8be6178 100644
--- a/source3/winbindd/winbindd.c
+++ b/source3/winbindd/winbindd.c
@@ -1230,7 +1230,7 @@ int main(int argc, char **argv, char **envp)
  	CatchSignal(SIGUSR2, SIG_IGN);
 
 	fault_setup();
-	dump_core_setup("winbindd");
+	dump_core_setup("winbindd", lp_logfile());
 
 	load_case_tables();
 
diff --git a/source3/wscript_build b/source3/wscript_build
index fd9e4f488b..cb3bbc29be 100755
--- a/source3/wscript_build
+++ b/source3/wscript_build
@@ -69,7 +69,8 @@ LIB_SRC = '''
           lib/util_transfer_file.c
           lib/addrchange.c
           ${TDB_LIB_SRC}
-          ../lib/util/debug_s3.c ../lib/util/fault.c
+          ../lib/util/debug_s3.c
+          lib/dumpcore.c
           lib/interface.c lib/pidfile.c
           lib/system.c lib/sendfile.c lib/recvfile.c lib/time.c
           lib/username.c