summaryrefslogtreecommitdiff
path: root/lib/util
diff options
context:
space:
mode:
Diffstat (limited to 'lib/util')
-rw-r--r--lib/util/fault.c380
1 files changed, 380 insertions, 0 deletions
diff --git a/lib/util/fault.c b/lib/util/fault.c
new file mode 100644
index 0000000000..2ffd5dbd6d
--- /dev/null
+++ b/lib/util/fault.c
@@ -0,0 +1,380 @@
+/*
+ Unix SMB/CIFS implementation.
+ Critical Fault handling
+ Copyright (C) Andrew Tridgell 1992-1998
+ Copyright (C) Tim Prouty 2009
+
+ 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"
+
+#ifdef HAVE_SYS_SYSCTL_H
+#include <sys/sysctl.h>
+#endif
+
+
+#ifdef HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#endif
+
+static char *corepath;
+
+/*******************************************************************
+report a fault
+********************************************************************/
+static void fault_report(int sig)
+{
+ static int counter;
+
+ if (counter) _exit(1);
+
+ 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"));
+ DEBUGSEP(0);
+
+ smb_panic("internal error");
+
+ /* smb_panic() never returns, so this is really redundent */
+ exit(1);
+}
+
+/****************************************************************************
+catch serious errors
+****************************************************************************/
+static void sig_fault(int sig)
+{
+ fault_report(sig);
+}
+
+/*******************************************************************
+setup our fault handlers
+********************************************************************/
+void fault_setup(void)
+{
+#ifdef SIGSEGV
+ CatchSignal(SIGSEGV, sig_fault);
+#endif
+#ifdef SIGBUS
+ CatchSignal(SIGBUS, sig_fault);
+#endif
+#ifdef SIGABRT
+ CatchSignal(SIGABRT, sig_fault);
+#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;
+
+ 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)
+{
+ 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)
+{
+ 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 */
+}