docs: use the stdarg.option entity in the popt.common.samba entity
[Samba/gebeck_regimport.git] / source3 / lib / dumpcore.c
blob90acc1679b69d3ab2e8f9cabf177cf15cbdd3507
1 /*
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/>.
28 #include "includes.h"
29 #include "system/filesys.h"
31 #ifdef HAVE_SYS_SYSCTL_H
32 #include <sys/sysctl.h>
33 #endif
35 #ifdef HAVE_SYS_PRCTL_H
36 #include <sys/prctl.h>
37 #endif
39 static char *corepath;
41 /**
42 * Build up the default corepath as "<logbase>/cores/<progname>"
44 static char *get_default_corepath(const char *logbase, const char *progname)
46 char *tmp_corepath;
48 /* Setup core dir in logbase. */
49 tmp_corepath = talloc_asprintf(NULL, "%s/cores", logbase);
50 if (!tmp_corepath)
51 return NULL;
53 if ((mkdir(tmp_corepath, 0700) == -1) && errno != EEXIST)
54 goto err_out;
56 if (chmod(tmp_corepath, 0700) == -1)
57 goto err_out;
59 talloc_free(tmp_corepath);
61 /* Setup progname-specific core subdir */
62 tmp_corepath = talloc_asprintf(NULL, "%s/cores/%s", logbase, progname);
63 if (!tmp_corepath)
64 return NULL;
66 if (mkdir(tmp_corepath, 0700) == -1 && errno != EEXIST)
67 goto err_out;
69 if (chown(tmp_corepath, getuid(), getgid()) == -1)
70 goto err_out;
72 if (chmod(tmp_corepath, 0700) == -1)
73 goto err_out;
75 return tmp_corepath;
77 err_out:
78 talloc_free(tmp_corepath);
79 return NULL;
83 /**
84 * Get the FreeBSD corepath.
86 * On FreeBSD the current working directory is ignored when creating a core
87 * file. Instead the core directory is controlled via sysctl. This consults
88 * the value of "kern.corefile" so the correct corepath can be printed out
89 * before dump_core() calls abort.
91 #if (defined(FREEBSD) && defined(HAVE_SYSCTLBYNAME))
92 static char *get_freebsd_corepath(void)
94 char *tmp_corepath = NULL;
95 char *end = NULL;
96 size_t len = 128;
97 int ret;
99 /* Loop with increasing sizes so we don't allocate too much. */
100 do {
101 if (len > 1024) {
102 goto err_out;
105 tmp_corepath = (char *)talloc_realloc(NULL, tmp_corepath,
106 char, len);
107 if (!tmp_corepath) {
108 return NULL;
111 ret = sysctlbyname("kern.corefile", tmp_corepath, &len, NULL,
113 if (ret == -1) {
114 if (errno != ENOMEM) {
115 DEBUG(0, ("sysctlbyname failed getting "
116 "kern.corefile %s\n",
117 strerror(errno)));
118 goto err_out;
121 /* Not a large enough array, try a bigger one. */
122 len = len << 1;
124 } while (ret == -1);
126 /* Strip off the common filename expansion */
127 if ((end = strrchr_m(tmp_corepath, '/'))) {
128 *end = '\0';
131 return tmp_corepath;
133 err_out:
134 if (tmp_corepath) {
135 talloc_free(tmp_corepath);
137 return NULL;
139 #endif
141 #if defined(HAVE_SYS_KERNEL_PROC_CORE_PATTERN)
144 * Get the Linux corepath.
146 * On Linux the contents of /proc/sys/kernel/core_pattern indicates the
147 * location of the core path.
149 static char *get_linux_corepath(void)
151 char *end;
152 int fd;
153 char *result;
155 fd = open("/proc/sys/kernel/core_pattern", O_RDONLY, 0);
156 if (fd == -1) {
157 return NULL;
160 result = afdgets(fd, NULL, 0);
161 close(fd);
163 if (result == NULL) {
164 return NULL;
167 if (result[0] != '/') {
169 * No absolute path, use the default (cwd)
171 TALLOC_FREE(result);
172 return NULL;
174 /* Strip off the common filename expansion */
176 end = strrchr_m(result, '/');
178 if ((end != result) /* this would be the only / */
179 && (end != NULL)) {
180 *end = '\0';
182 return result;
184 #endif
188 * Try getting system-specific corepath if one exists.
190 * If the system doesn't define a corepath, then the default is used.
192 static char *get_corepath(const char *logbase, const char *progname)
194 #if (defined(FREEBSD) && defined(HAVE_SYSCTLBYNAME))
195 char *tmp_corepath = NULL;
196 tmp_corepath = get_freebsd_corepath();
198 /* If this has been set correctly, we're done. */
199 if (tmp_corepath) {
200 return tmp_corepath;
202 #endif
204 #if defined(HAVE_SYS_KERNEL_PROC_CORE_PATTERN)
205 char *tmp_corepath = NULL;
206 tmp_corepath = get_linux_corepath();
208 /* If this has been set correctly, we're done. */
209 if (tmp_corepath) {
210 return tmp_corepath;
212 #endif
214 /* Fall back to the default. */
215 return get_default_corepath(logbase, progname);
218 /*******************************************************************
219 make all the preparations to safely dump a core file
220 ********************************************************************/
222 void dump_core_setup(const char *progname, const char *log_file)
224 char *logbase = NULL;
225 char *end = NULL;
227 if (log_file && *log_file) {
228 if (asprintf(&logbase, "%s", log_file) < 0) {
229 return;
231 if ((end = strrchr_m(logbase, '/'))) {
232 *end = '\0';
234 } else {
235 /* We will end up here if the log file is given on the command
236 * line by the -l option but the "log file" option is not set
237 * in smb.conf.
239 if (asprintf(&logbase, "%s", get_dyn_LOGFILEBASE()) < 0) {
240 return;
244 SMB_ASSERT(progname != NULL);
246 corepath = get_corepath(logbase, progname);
247 if (!corepath) {
248 DEBUG(0, ("Unable to setup corepath for %s: %s\n", progname,
249 strerror(errno)));
250 goto out;
254 #ifdef HAVE_GETRLIMIT
255 #ifdef RLIMIT_CORE
257 struct rlimit rlp;
258 getrlimit(RLIMIT_CORE, &rlp);
259 rlp.rlim_cur = MAX(16*1024*1024,rlp.rlim_cur);
260 setrlimit(RLIMIT_CORE, &rlp);
261 getrlimit(RLIMIT_CORE, &rlp);
262 DEBUG(3,("Maximum core file size limits now %d(soft) %d(hard)\n",
263 (int)rlp.rlim_cur,(int)rlp.rlim_max));
265 #endif
266 #endif
268 /* FIXME: if we have a core-plus-pid facility, configurably set
269 * this up here.
271 out:
272 SAFE_FREE(logbase);
275 void dump_core(void)
277 static bool called;
279 if (called) {
280 DEBUG(0, ("dump_core() called recursive\n"));
281 exit(1);
283 called = true;
285 /* Note that even if core dumping has been disabled, we still set up
286 * the core path. This is to handle the case where core dumping is
287 * turned on in smb.conf and the relevant daemon is not restarted.
289 if (!lp_enable_core_files()) {
290 DEBUG(0, ("Exiting on internal error (core file administratively disabled)\n"));
291 exit(1);
294 #if DUMP_CORE
295 /* If we're running as non root we might not be able to dump the core
296 * file to the corepath. There must not be an unbecome_root() before
297 * we call abort(). */
298 if (geteuid() != sec_initial_uid()) {
299 become_root();
302 if (corepath == NULL) {
303 DEBUG(0, ("Can not dump core: corepath not set up\n"));
304 exit(1);
307 if (*corepath != '\0') {
308 /* The chdir might fail if we dump core before we finish
309 * processing the config file.
311 if (chdir(corepath) != 0) {
312 DEBUG(0, ("unable to change to %s\n", corepath));
313 DEBUGADD(0, ("refusing to dump core\n"));
314 exit(1);
317 DEBUG(0,("dumping core in %s\n", corepath));
320 umask(~(0700));
321 dbgflush();
323 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
324 /* On Linux we lose the ability to dump core when we change our user
325 * ID. We know how to dump core safely, so let's make sure we have our
326 * dumpable flag set.
328 prctl(PR_SET_DUMPABLE, 1);
329 #endif
331 /* Ensure we don't have a signal handler for abort. */
332 #ifdef SIGABRT
333 CatchSignal(SIGABRT, SIG_DFL);
334 #endif
336 abort();
338 #else /* DUMP_CORE */
339 exit(1);
340 #endif /* DUMP_CORE */