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r19957: Initial framework to make winbindd robust

against tdb corruption. Needs fleshing out
(and I forgot one record type) and needs helpful
suggestion from Volker to validate freelist,
but should give an idea of how this will look.
Jeremy.
This commit is contained in:
Jeremy Allison 2006-11-29 23:20:22 +00:00 committed by Gerald (Jerry) Carter
parent b6bf2e4267
commit 8eb53f74e4
4 changed files with 248 additions and 2 deletions

View File

@ -36,4 +36,6 @@
#define SIGNAL_CAST (RETSIGTYPE (*)(int))
#endif
#include <setjmp.h>
#endif

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@ -1182,7 +1182,7 @@ enum {
OPT_GROUP_INFO,
};
int main(int argc, char **argv)
int main(int argc, char **argv, char **envp)
{
int opt;

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@ -879,7 +879,7 @@ static void process_loop(void)
struct winbindd_state server_state; /* Server state information */
int main(int argc, char **argv)
int main(int argc, char **argv, char **envp)
{
pstring logfile;
static BOOL Fork = True;
@ -1022,6 +1022,17 @@ int main(int argc, char **argv)
pidfile_create("winbindd");
if (winbindd_validate_cache()) {
/* We have a bad cache, but luckily we
just deleted it. Restart ourselves */
int i;
/* Ensure we have no open low fd's. */
for (i = 3; i < 100; i++) {
close(i);
}
return execve(argv[0], argv, envp);
}
#if HAVE_SETPGID
/*
* If we're interactive we want to set our own process group for
@ -1040,6 +1051,9 @@ int main(int argc, char **argv)
exit(1);
}
/* Ensure all cache and idmap caches are consistent
before we startup. */
/* React on 'smbcontrol winbindd reload-config' in the same way
as to SIGHUP signal */
message_register(MSG_SMB_CONF_UPDATED, msg_reload_services);

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@ -2594,6 +2594,236 @@ BOOL get_global_winbindd_state_offline(void)
return global_winbindd_offline_state;
}
/***********************************************************************
Validate functions for all possible cache tdb keys.
***********************************************************************/
static int validate_seqnum(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
static int validate_ns(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
static int validate_sn(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
static int validate_u(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
static int validate_loc_pol(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
static int validate_pwd_pol(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
static int validate_cred(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
static int validate_ul(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
static int validate_gl(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
static int validate_ug(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
static int validate_ua(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
static int validate_gm(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
static int validate_trustdoms(TDB_DATA kbuf, TDB_DATA dbuf)
{
return 0;
}
/***********************************************************************
A list of all possible cache tdb keys with associated validation
functions.
***********************************************************************/
struct key_val_struct {
const char *keyname;
int (*validate_data_fn)(TDB_DATA kbuf, TDB_DATA dbuf);
} key_val[] = {
{"SEQNUM/", validate_seqnum},
{"NS/", validate_ns},
{"SN/", validate_sn},
{"U/", validate_u},
{"LOC_POL/", validate_loc_pol},
{"PWD_POL/", validate_pwd_pol},
{"CRED/", validate_cred},
{"UL/", validate_ul},
{"GL/", validate_gl},
{"UG/", validate_ug},
{"UA", validate_ua},
{"GM/", validate_gm},
{"TRUSTDOMS/", validate_trustdoms},
{NULL, NULL}
};
/***********************************************************************
Function to look at every entry in the tdb and validate it as far as
possible.
***********************************************************************/
static int cache_traverse_validate_fn(TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
{
int i;
/* Ensure key is valid. */
if (kbuf.dsize < 3) {
return 1; /* terminate. */
}
/* Ensure key is a string. */
if (kbuf.dptr[kbuf.dsize] != '\0') {
return 1; /* terminate. */
}
for (i = 0; key_val[i].keyname; i++) {
if (strncmp(key_val[i].keyname, kbuf.dptr, strlen(key_val[i].keyname)) == 0) {
if (key_val[i].validate_data_fn(kbuf, dbuf)) {
return 1; /* terminate. */
}
}
}
return 0;
}
/* Handle any signals generated when validating a possibly
bad cache tdb. */
static jmp_buf jmpbuf;
#ifdef SIGSEGV
static void sig_segv(int sig)
{
longjmp(jmpbuf, SIGSEGV);
}
#endif
#ifdef SIGBUS
static void sig_bus(int sig)
{
longjmp(jmpbuf, SIGBUS);
}
#endif
#ifdef SIGABRT
static void sig_abrt(int sig)
{
longjmp(jmpbuf, SIGABRT);
}
#endif
/***********************************************************************
Try and validate every entry in the winbindd cache. If we fail here,
delete the cache tdb and return non-zero - the caller (main winbindd
function) will restart us as we don't know if we crashed or not.
***********************************************************************/
int winbindd_validate_cache(void)
{
BOOL ret = -1;
int fd = -1;
TDB_CONTEXT *tdb = NULL;
const char *cache_path = lock_path("winbindd_cache.tdb");
#ifdef SIGSEGV
void (*old_segv_handler)(int) = CatchSignal(SIGSEGV,SIGNAL_CAST sig_segv);
#endif
#ifdef SIGBUS
void (*old_bus_handler)(int) = CatchSignal(SIGBUS,SIGNAL_CAST sig_bus);
#endif
#ifdef SIGABRT
void (*old_abrt_handler)(int) = CatchSignal(SIGABRT,SIGNAL_CAST sig_abrt);
#endif
switch((ret = setjmp(jmpbuf))) {
case 0:
ret = -1;
break;
case SIGSEGV:
case SIGBUS:
case SIGABRT:
default:
goto out;
}
tdb = tdb_open_log(cache_path,
WINBINDD_CACHE_TDB_DEFAULT_HASH_SIZE,
lp_winbind_offline_logon() ? TDB_DEFAULT : (TDB_DEFAULT | TDB_CLEAR_IF_FIRST),
O_RDWR|O_CREAT, 0600);
if (!tdb) {
goto out;
}
fd = tdb_fd(tdb);
/* Now traverse the cache to validate it. */
if (tdb_traverse(tdb, cache_traverse_validate_fn, NULL)) {
goto out;
}
DEBUG(10,("winbindd_validate_cache: cache %s is good\n", cache_path));
ret = 0; /* Cache is good. */
out:
/* Ensure if we segv on exit we use the original
handlers to avoid a loop. */
#ifdef SIGSEGV
CatchSignal(SIGSEGV,SIGNAL_CAST old_segv_handler);
#endif
#ifdef SIGBUS
CatchSignal(SIGBUS,SIGNAL_CAST old_bus_handler);
#endif
#ifdef SIGABRT
CatchSignal(SIGABRT,SIGNAL_CAST old_abrt_handler);
#endif
if (tdb) {
if (ret == 0) {
tdb_close(tdb);
} else if (fd != -1) {
close(fd);
}
}
if (ret) {
unlink(cache_path);
}
return ret;
}
/* the cache backend methods are exposed via this structure */
struct winbindd_methods cache_methods = {
True,