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 "lib/util/util_file.h"
30 #include "system/filesys.h"
32 #ifdef HAVE_SYS_SYSCTL_H
33 #include <sys/sysctl.h>
36 #ifdef HAVE_SYS_PRCTL_H
37 #include <sys/prctl.h>
40 static char *corepath;
41 static bool using_helper_binary = false;
44 * Build up the default corepath as "<logbase>/cores/<progname>"
46 static char *get_default_corepath(const char *logbase, const char *progname)
48 const mode_t mode = 0700;
49 const uid_t uid = getuid();
52 /* Setup core dir in logbase. */
53 tmp_corepath = talloc_asprintf(NULL, "%s/cores", logbase);
55 DEBUG(0, ("Out of memory\n"));
59 if (!directory_create_or_exist_strict(tmp_corepath, uid, mode)) {
60 DEBUG(0, ("Failed to create %s for user %d with mode 0%o\n",
61 tmp_corepath, (int)uid, (int)mode));
65 /* Setup progname-specific core subdir */
66 tmp_corepath = talloc_asprintf_append(tmp_corepath, "/%s", progname);
68 DEBUG(0, ("Out of memory\n"));
72 if (!directory_create_or_exist(tmp_corepath, mode)) {
73 DEBUG(0, ("Failed to create %s for user %d with mode 0%o\n",
74 tmp_corepath, (int)uid, (int)mode));
81 talloc_free(tmp_corepath);
87 * Get the FreeBSD corepath.
89 * On FreeBSD the current working directory is ignored when creating a core
90 * file. Instead the core directory is controlled via sysctl. This consults
91 * the value of "kern.corefile" so the correct corepath can be printed out
92 * before dump_core() calls abort.
94 #if (defined(FREEBSD) && defined(HAVE_SYSCTLBYNAME))
95 static char *get_freebsd_corepath(void)
97 char *tmp_corepath = NULL;
102 /* Loop with increasing sizes so we don't allocate too much. */
108 tmp_corepath = (char *)talloc_realloc(NULL, tmp_corepath,
114 ret = sysctlbyname("kern.corefile", tmp_corepath, &len, NULL,
117 if (errno != ENOMEM) {
118 DEBUG(0, ("sysctlbyname failed getting "
119 "kern.corefile %s\n",
124 /* Not a large enough array, try a bigger one. */
129 /* Strip off the common filename expansion */
130 if ((end = strrchr_m(tmp_corepath, '/'))) {
138 talloc_free(tmp_corepath);
144 #if defined(HAVE_SYS_KERNEL_PROC_CORE_PATTERN)
147 * Get the Linux corepath.
149 * On Linux the contents of /proc/sys/kernel/core_pattern indicates the
150 * location of the core path.
152 static char *get_linux_corepath(void)
158 fd = open("/proc/sys/kernel/core_pattern", O_RDONLY, 0);
163 result = afdgets(fd, NULL, 0);
166 if (result == NULL) {
170 if (result[0] != '/') {
172 * No absolute path, use the default (cwd)
174 if (result[0] == '|') {
176 * Core dump handled by helper binaries
178 using_helper_binary = true;
183 /* Strip off the common filename expansion */
185 end = strrchr_m(result, '/');
187 if ((end != result) /* this would be the only / */
197 * Try getting system-specific corepath if one exists.
199 * If the system doesn't define a corepath, then the default is used.
201 static char *get_corepath(const char *logbase, const char *progname)
203 #if (defined(FREEBSD) && defined(HAVE_SYSCTLBYNAME))
204 char *tmp_corepath = NULL;
205 tmp_corepath = get_freebsd_corepath();
207 /* If this has been set correctly, we're done. */
213 #if defined(HAVE_SYS_KERNEL_PROC_CORE_PATTERN)
214 char *tmp_corepath = NULL;
215 tmp_corepath = get_linux_corepath();
217 /* If this has been set correctly, we're done. */
223 /* Fall back to the default. */
224 return get_default_corepath(logbase, progname);
227 /*******************************************************************
228 make all the preparations to safely dump a core file
229 ********************************************************************/
231 void dump_core_setup(const char *progname, const char *log_file)
233 char *logbase = NULL;
236 if (log_file && *log_file) {
237 if (asprintf(&logbase, "%s", log_file) < 0) {
240 if ((end = strrchr_m(logbase, '/'))) {
244 /* We will end up here if the log file is given on the command
245 * line by the -l option but the "log file" option is not set
248 if (asprintf(&logbase, "%s", get_dyn_LOGFILEBASE()) < 0) {
253 SMB_ASSERT(progname != NULL);
255 corepath = get_corepath(logbase, progname);
257 DEBUG(0, ("Unable to setup corepath for %s: %s\n", progname,
262 /* FIXME: if we have a core-plus-pid facility, configurably set
274 DEBUG(0, ("dump_core() called recursive\n"));
279 /* Note that even if core dumping has been disabled, we still set up
280 * the core path. This is to handle the case where core dumping is
281 * turned on in smb.conf and the relevant daemon is not restarted.
283 if (!lp_enable_core_files()) {
284 DEBUG(0, ("Exiting on internal error (core file administratively disabled)\n"));
289 /* If we're running as non root we might not be able to dump the core
290 * file to the corepath. There must not be an unbecome_root() before
291 * we call abort(). */
292 if (geteuid() != sec_initial_uid()) {
296 if (corepath == NULL) {
297 DEBUG(0, ("Can not dump core: corepath not set up\n"));
301 if (*corepath != '\0') {
303 * Check whether coredump is handled by helper binaries or not.
304 * If so skip chdir().
306 if (!using_helper_binary) {
307 /* The chdir might fail if we dump core before we finish
308 * processing the config file.
310 if (chdir(corepath) != 0) {
311 DEBUG(0, ("unable to change to %s\n", corepath));
312 DEBUGADD(0, ("refusing to dump core\n"));
316 DEBUG(0,("dumping core in %s\n", corepath));
318 DEBUG(0,("coredump is handled by helper binary "
319 "specified at /proc/sys/kernel/core_pattern\n"));
326 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
327 /* On Linux we lose the ability to dump core when we change our user
328 * ID. We know how to dump core safely, so let's make sure we have our
331 prctl(PR_SET_DUMPABLE, 1);
334 /* Ensure we don't have a signal handler for abort. */
336 CatchSignal(SIGABRT, SIG_DFL);
341 #else /* DUMP_CORE */
343 #endif /* DUMP_CORE */