2 Unix SMB/CIFS implementation.
3 Samba utility functions
5 Copyright (C) Andrew Tridgell 1992-2011
7 based on old fault.c code, which had:
9 Copyright (C) Jeremy Allison 2001-2007
10 Copyright (C) Simo Sorce 2001
11 Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003
12 Copyright (C) James Peach 2006
14 This program is free software; you can redistribute it and/or modify
15 it under the terms of the GNU General Public License as published by
16 the Free Software Foundation; either version 3 of the License, or
17 (at your option) any later version.
19 This program is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 GNU General Public License for more details.
24 You should have received a copy of the GNU General Public License
25 along with this program. If not, see <http://www.gnu.org/licenses/>.
29 #include "system/filesys.h"
31 #ifdef HAVE_SYS_SYSCTL_H
32 #include <sys/sysctl.h>
35 #ifdef HAVE_SYS_PRCTL_H
36 #include <sys/prctl.h>
39 static char *corepath;
40 static bool using_helper_binary = false;
43 * Build up the default corepath as "<logbase>/cores/<progname>"
45 static char *get_default_corepath(const char *logbase, const char *progname)
47 const mode_t mode = 0700;
48 const uid_t uid = getuid();
51 /* Setup core dir in logbase. */
52 tmp_corepath = talloc_asprintf(NULL, "%s/cores", logbase);
54 DEBUG(0, ("Out of memory\n"));
58 if (!directory_create_or_exist_strict(tmp_corepath, uid, mode)) {
59 DEBUG(0, ("Failed to create %s for user %d with mode 0%o\n",
60 tmp_corepath, (int)uid, (int)mode));
64 /* Setup progname-specific core subdir */
65 tmp_corepath = talloc_asprintf_append(tmp_corepath, "/%s", progname);
67 DEBUG(0, ("Out of memory\n"));
71 if (!directory_create_or_exist(tmp_corepath, mode)) {
72 DEBUG(0, ("Failed to create %s for user %d with mode 0%o\n",
73 tmp_corepath, (int)uid, (int)mode));
80 talloc_free(tmp_corepath);
86 * Get the FreeBSD corepath.
88 * On FreeBSD the current working directory is ignored when creating a core
89 * file. Instead the core directory is controlled via sysctl. This consults
90 * the value of "kern.corefile" so the correct corepath can be printed out
91 * before dump_core() calls abort.
93 #if (defined(FREEBSD) && defined(HAVE_SYSCTLBYNAME))
94 static char *get_freebsd_corepath(void)
96 char *tmp_corepath = NULL;
101 /* Loop with increasing sizes so we don't allocate too much. */
107 tmp_corepath = (char *)talloc_realloc(NULL, tmp_corepath,
113 ret = sysctlbyname("kern.corefile", tmp_corepath, &len, NULL,
116 if (errno != ENOMEM) {
117 DEBUG(0, ("sysctlbyname failed getting "
118 "kern.corefile %s\n",
123 /* Not a large enough array, try a bigger one. */
128 /* Strip off the common filename expansion */
129 if ((end = strrchr_m(tmp_corepath, '/'))) {
137 talloc_free(tmp_corepath);
143 #if defined(HAVE_SYS_KERNEL_PROC_CORE_PATTERN)
146 * Get the Linux corepath.
148 * On Linux the contents of /proc/sys/kernel/core_pattern indicates the
149 * location of the core path.
151 static char *get_linux_corepath(void)
157 fd = open("/proc/sys/kernel/core_pattern", O_RDONLY, 0);
162 result = afdgets(fd, NULL, 0);
165 if (result == NULL) {
169 if (result[0] != '/') {
171 * No absolute path, use the default (cwd)
173 if (result[0] == '|') {
175 * Core dump handled by helper binaries
177 using_helper_binary = true;
182 /* Strip off the common filename expansion */
184 end = strrchr_m(result, '/');
186 if ((end != result) /* this would be the only / */
196 * Try getting system-specific corepath if one exists.
198 * If the system doesn't define a corepath, then the default is used.
200 static char *get_corepath(const char *logbase, const char *progname)
202 #if (defined(FREEBSD) && defined(HAVE_SYSCTLBYNAME))
203 char *tmp_corepath = NULL;
204 tmp_corepath = get_freebsd_corepath();
206 /* If this has been set correctly, we're done. */
212 #if defined(HAVE_SYS_KERNEL_PROC_CORE_PATTERN)
213 char *tmp_corepath = NULL;
214 tmp_corepath = get_linux_corepath();
216 /* If this has been set correctly, we're done. */
222 /* Fall back to the default. */
223 return get_default_corepath(logbase, progname);
226 /*******************************************************************
227 make all the preparations to safely dump a core file
228 ********************************************************************/
230 void dump_core_setup(const char *progname, const char *log_file)
232 char *logbase = NULL;
235 if (log_file && *log_file) {
236 if (asprintf(&logbase, "%s", log_file) < 0) {
239 if ((end = strrchr_m(logbase, '/'))) {
243 /* We will end up here if the log file is given on the command
244 * line by the -l option but the "log file" option is not set
247 if (asprintf(&logbase, "%s", get_dyn_LOGFILEBASE()) < 0) {
252 SMB_ASSERT(progname != NULL);
254 corepath = get_corepath(logbase, progname);
256 DEBUG(0, ("Unable to setup corepath for %s: %s\n", progname,
261 /* FIXME: if we have a core-plus-pid facility, configurably set
273 DEBUG(0, ("dump_core() called recursive\n"));
278 /* Note that even if core dumping has been disabled, we still set up
279 * the core path. This is to handle the case where core dumping is
280 * turned on in smb.conf and the relevant daemon is not restarted.
282 if (!lp_enable_core_files()) {
283 DEBUG(0, ("Exiting on internal error (core file administratively disabled)\n"));
288 /* If we're running as non root we might not be able to dump the core
289 * file to the corepath. There must not be an unbecome_root() before
290 * we call abort(). */
291 if (geteuid() != sec_initial_uid()) {
295 if (corepath == NULL) {
296 DEBUG(0, ("Can not dump core: corepath not set up\n"));
300 if (*corepath != '\0') {
302 * Check whether coredump is handled by helper binaries or not.
303 * If so skip chdir().
305 if (!using_helper_binary) {
306 /* The chdir might fail if we dump core before we finish
307 * processing the config file.
309 if (chdir(corepath) != 0) {
310 DEBUG(0, ("unable to change to %s\n", corepath));
311 DEBUGADD(0, ("refusing to dump core\n"));
315 DEBUG(0,("dumping core in %s\n", corepath));
317 DEBUG(0,("coredump is handled by helper binary "
318 "specified at /proc/sys/kernel/core_pattern\n"));
325 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
326 /* On Linux we lose the ability to dump core when we change our user
327 * ID. We know how to dump core safely, so let's make sure we have our
330 prctl(PR_SET_DUMPABLE, 1);
333 /* Ensure we don't have a signal handler for abort. */
335 CatchSignal(SIGABRT, SIG_DFL);
340 #else /* DUMP_CORE */
342 #endif /* DUMP_CORE */