/* ----------------------------------------------------------------------- *
*
* lookup_program.c - module for Linux automount to access an
* automount map via a query program
*
* Copyright 1997 Transmeta Corporation - All Rights Reserved
* Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
*
* 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, Inc., 675 Mass Ave, Cambridge MA 02139,
* USA; either version 2 of the License, or (at your option) any later
* version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
#include <ctype.h>
#include <malloc.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/times.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <poll.h>
#define MODULE_LOOKUP
#include "automount.h"
#include "nsswitch.h"
#define MAPFMT_DEFAULT "sun"
#define MODPREFIX "lookup(program): "
struct lookup_context {
const char *mapname;
char *mapfmt;
struct parse_mod *parse;
};
struct parse_context {
char *optstr; /* Mount options */
char *macros; /* Map wide macro defines */
struct substvar *subst; /* $-substitutions */
int slashify_colons; /* Change colons to slashes? */
};
int lookup_version = AUTOFS_LOOKUP_VERSION; /* Required by protocol */
static int do_init(const char *mapfmt,
int argc, const char *const *argv,
struct lookup_context *ctxt, unsigned int reinit)
{
int ret = 0;
if (argc < 1) {
logmsg(MODPREFIX "No map name");
ret = 1;
goto out;
}
ctxt->mapname = argv[0];
if (ctxt->mapname[0] != '/') {
logmsg(MODPREFIX "program map %s is not an absolute pathname",
ctxt->mapname);
ret = 1;
goto out;
}
if (access(ctxt->mapname, X_OK)) {
logmsg(MODPREFIX "program map %s missing or not executable",
ctxt->mapname);
ret = 1;
goto out;
}
if (!mapfmt)
mapfmt = MAPFMT_DEFAULT;
ctxt->mapfmt = strdup(mapfmt);
if (!ctxt->mapfmt) {
logmsg(MODPREFIX "failed to allocate storage for map format");
ret = 1;
goto out;
}
if (reinit) {
ret = reinit_parse(ctxt->parse, mapfmt, MODPREFIX, argc - 1, argv + 1);
if (ret)
logmsg(MODPREFIX "failed to reinit parse context");
} else {
ctxt->parse = open_parse(mapfmt, MODPREFIX, argc - 1, argv + 1);
if (!ctxt->parse) {
logmsg(MODPREFIX "failed to open parse context");
ret = 1;
}
}
out:
if (ret && ctxt->mapfmt)
free(ctxt->mapfmt);
return ret;
}
int lookup_init(const char *mapfmt,
int argc, const char *const *argv, void **context)
{
struct lookup_context *ctxt;
char buf[MAX_ERR_BUF];
*context = NULL;
ctxt = malloc(sizeof(struct lookup_context));
if (!ctxt) {
char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
logerr(MODPREFIX "malloc: %s", estr);
return 1;
}
memset(ctxt, 0, sizeof(struct lookup_context));
if (do_init(mapfmt, argc, argv, ctxt, 0)) {
free(ctxt);
return 1;
}
*context = ctxt;
return 0;
}
int lookup_reinit(const char *mapfmt,
int argc, const char *const *argv, void **context)
{
struct lookup_context *ctxt = (struct lookup_context *) *context;
struct lookup_context *new;
char buf[MAX_ERR_BUF];
int ret;
new = malloc(sizeof(struct lookup_context));
if (!new) {
char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
logerr(MODPREFIX "malloc: %s", estr);
return 1;
}
memset(new, 0, sizeof(struct lookup_context));
new->parse = ctxt->parse;
ret = do_init(mapfmt, argc, argv, new, 1);
if (ret) {
free(new);
return 1;
}
*context = new;
free(ctxt->mapfmt);
free(ctxt);
return 0;
}
int lookup_read_master(struct master *master, time_t age, void *context)
{
return NSS_STATUS_UNKNOWN;
}
int lookup_read_map(struct autofs_point *ap, time_t age, void *context)
{
ap->entry->current = NULL;
master_source_current_signal(ap->entry);
return NSS_STATUS_UNKNOWN;
}
static char *lookup_one(struct autofs_point *ap,
const char *name, int name_len,
struct lookup_context *ctxt)
{
char *mapent = NULL, *mapp, *tmp;
char buf[MAX_ERR_BUF];
char errbuf[1024], *errp;
char ch;
int pipefd[2], epipefd[2];
struct pollfd pfd[2];
pid_t f;
enum state { st_space, st_map, st_done } state;
int quoted = 0;
int distance;
int alloci = 1;
int status;
char *prefix;
mapent = (char *) malloc(MAPENT_MAX_LEN + 1);
if (!mapent) {
char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
logerr(MODPREFIX "malloc: %s", estr);
return NULL;
}
/*
* By default use a prefix with standard environment
* variables to prevent system subversion by interpreted
* languages.
*/
if (defaults_force_std_prog_map_env())
prefix = NULL;
else
prefix = "AUTOFS_";
/*
* We don't use popen because we don't want to run /bin/sh plus we
* want to send stderr to the syslog, and we don't use spawnl()
* because we need the pipe hooks
*/
if (open_pipe(pipefd)) {
char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
logerr(MODPREFIX "pipe: %s", estr);
goto out_error;
}
if (open_pipe(epipefd)) {
close(pipefd[0]);
close(pipefd[1]);
goto out_error;
}
open_mutex_lock();
f = fork();
if (f < 0) {
char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
logerr(MODPREFIX "fork: %s", estr);
close(pipefd[0]);
close(pipefd[1]);
close(epipefd[0]);
close(epipefd[1]);
open_mutex_unlock();
goto out_error;
} else if (f == 0) {
reset_signals();
close(pipefd[0]);
close(epipefd[0]);
dup2(pipefd[1], STDOUT_FILENO);
dup2(epipefd[1], STDERR_FILENO);
close(pipefd[1]);
close(epipefd[1]);
if (chdir(ap->path))
warn(ap->logopt,
MODPREFIX "failed to set PWD to %s for map %s",
ap->path, ctxt->mapname);
/*
* MAPFMT_DEFAULT must be "sun" for ->parse_init() to have setup
* the macro table.
*/
if (ctxt->mapfmt && !strcmp(ctxt->mapfmt, MAPFMT_DEFAULT)) {
struct parse_context *pctxt = (struct parse_context *) ctxt->parse->context;
/* Add standard environment as seen by sun map parser */
pctxt->subst = addstdenv(pctxt->subst, prefix);
macro_setenv(pctxt->subst);
}
execl(ctxt->mapname, ctxt->mapname, name, NULL);
_exit(255); /* execl() failed */
}
close(pipefd[1]);
close(epipefd[1]);
open_mutex_unlock();
mapp = mapent;
errp = errbuf;
state = st_space;
pfd[0].fd = pipefd[0];
pfd[0].events = POLLIN;
pfd[1].fd = epipefd[0];
pfd[1].events = POLLIN;
while (1) {
int bytes;
if (poll(pfd, 2, -1) < 0 && errno != EINTR)
break;
if (pfd[0].fd == -1 && pfd[1].fd == -1)
break;
if ((pfd[0].revents & (POLLIN|POLLHUP)) == POLLHUP &&
(pfd[1].revents & (POLLIN|POLLHUP)) == POLLHUP)
break;
/* Parse maps from stdout */
if (pfd[0].revents) {
cont:
bytes = read(pipefd[0], &ch, 1);
if (bytes == 0)
goto next;
else if (bytes < 0) {
pfd[0].fd = -1;
state = st_done;
goto next;
}
if (!quoted && ch == '\\') {
quoted = 1;
goto cont;
}
switch (state) {
case st_space:
if (quoted || !isspace(ch)) {
*mapp++ = ch;
state = st_map;
}
break;
case st_map:
if (!quoted && ch == '\n') {
*mapp = '\0';
state = st_done;
break;
}
/* We overwrite up to 3 characters, so we
* need to make sure we have enough room
* in the buffer for this. */
/* else */
if (mapp - mapent >
((MAPENT_MAX_LEN+1) * alloci) - 3) {
/*
* Alloc another page for map entries.
*/
distance = mapp - mapent;
tmp = realloc(mapent,
((MAPENT_MAX_LEN + 1) *
++alloci));
if (!tmp) {
alloci--;
logerr(MODPREFIX "realloc: %s",
strerror(errno));
break;
}
mapent = tmp;
mapp = tmp + distance;
}
/*
* Eat \ quoting \n, otherwise pass it
* through for the parser
*/
if (quoted) {
if (ch == '\n')
*mapp++ = ' ';
else {
*mapp++ = '\\';
*mapp++ = ch;
}
} else
*mapp++ = ch;
break;
case st_done:
/* Eat characters till there's no more output */
break;
}
quoted = 0;
goto cont;
}
quoted = 0;
next:
/* Deal with stderr */
if (pfd[1].revents) {
while (1) {
bytes = read(epipefd[0], &ch, 1);
if (bytes == 0)
break;
else if (bytes < 0) {
pfd[1].fd = -1;
break;
} else if (ch == '\n') {
*errp = '\0';
if (errbuf[0])
logmsg(">> %s", errbuf);
errp = errbuf;
} else {
if (errp >= &errbuf[1023]) {
*errp = '\0';
logmsg(">> %s", errbuf);
errp = errbuf;
}
*(errp++) = ch;
}
}
}
}
if (mapp)
*mapp = '\0';
if (errp > errbuf) {
*errp = '\0';
logmsg(">> %s", errbuf);
}
close(pipefd[0]);
close(epipefd[0]);
if (waitpid(f, &status, 0) != f) {
char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
logerr(MODPREFIX "waitpid: %s", estr);
goto out_error;
}
if (mapp == mapent || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
info(ap->logopt, MODPREFIX "lookup for %s failed", name);
goto out_error;
}
return mapent;
out_error:
if (mapent)
free(mapent);
return NULL;
}
static int lookup_amd_defaults(struct autofs_point *ap,
struct map_source *source,
struct lookup_context *ctxt)
{
struct mapent_cache *mc = source->mc;
char *ment = lookup_one(ap, "/defaults", 9, ctxt);
if (ment) {
char *start = ment + 9;
int ret;
while (isblank(*start))
start++;
cache_writelock(mc);
ret = cache_update(mc, source, "/defaults", start, monotonic_time(NULL));
cache_unlock(mc);
if (ret == CHE_FAIL) {
free(ment);
return NSS_STATUS_UNAVAIL;
}
free(ment);
}
return NSS_STATUS_SUCCESS;
}
static int match_key(struct autofs_point *ap,
struct map_source *source,
const char *name, int name_len,
char **mapent, struct lookup_context *ctxt)
{
unsigned int is_amd_format = source->flags & MAP_FLAG_FORMAT_AMD;
struct mapent_cache *mc = source->mc;
char buf[MAX_ERR_BUF];
char *ment;
char *lkp_key;
size_t lkp_len;
char *prefix;
int ret;
if (is_amd_format) {
ret = lookup_amd_defaults(ap, source, ctxt);
if (ret != NSS_STATUS_SUCCESS) {
warn(ap->logopt,
MODPREFIX "failed to save /defaults entry");
}
}
if (!is_amd_format) {
lkp_key = strdup(name);
lkp_len = name_len;
} else {
size_t len;
if (ap->pref)
len = strlen(ap->pref) + strlen(name);
else
len = strlen(name);
lkp_key = malloc(len + 1);
if (!lkp_key) {
char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
error(ap->logopt, MODPREFIX "malloc: %s", estr);
return NSS_STATUS_UNAVAIL;
}
if (ap->pref) {
strcpy(lkp_key, ap->pref);
strcat(lkp_key, name);
} else
strcpy(lkp_key, name);
lkp_len = len;
}
ment = lookup_one(ap, lkp_key, lkp_len, ctxt);
if (ment) {
char *start = ment;
if (is_amd_format) {
start = ment + lkp_len;
while (isblank(*start))
start++;
}
cache_writelock(mc);
ret = cache_update(mc, source, lkp_key, start, monotonic_time(NULL));
cache_unlock(mc);
if (ret == CHE_FAIL) {
free(ment);
free(lkp_key);
return NSS_STATUS_UNAVAIL;
}
*mapent = strdup(start);
if (!*mapent) {
char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
error(ap->logopt, MODPREFIX "malloc: %s", estr);
free(lkp_key);
free(ment);
return NSS_STATUS_UNAVAIL;
}
free(lkp_key);
free(ment);
return NSS_STATUS_SUCCESS;
}
if (!is_amd_format) {
free(lkp_key);
return NSS_STATUS_NOTFOUND;
}
ret = NSS_STATUS_NOTFOUND;
/*
* Now strip successive directory components and try a
* match against map entries ending with a wildcard and
* finally try the wilcard entry itself.
*/
while ((prefix = strrchr(lkp_key, '/'))) {
char *match;
size_t len;
*prefix = '\0';
len = strlen(lkp_key) + 3;
match = malloc(len);
if (!match) {
char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
error(ap->logopt, MODPREFIX "malloc: %s", estr);
free(lkp_key);
return NSS_STATUS_UNAVAIL;
}
len--;
strcpy(match, lkp_key);
strcat(match, "/*");
ment = lookup_one(ap, match, len, ctxt);
if (ment) {
char *start = ment + len;
while (isblank(*start))
start++;
cache_writelock(mc);
ret = cache_update(mc, source, match, start, monotonic_time(NULL));
cache_unlock(mc);
if (ret == CHE_FAIL) {
free(match);
free(ment);
free(lkp_key);
return NSS_STATUS_UNAVAIL;
}
free(match);
*mapent = strdup(start);
if (!*mapent) {
char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
error(ap->logopt, MODPREFIX "malloc: %s", estr);
free(ment);
free(lkp_key);
return NSS_STATUS_UNAVAIL;
}
free(ment);
free(lkp_key);
return NSS_STATUS_SUCCESS;
}
free(match);
}
free(lkp_key);
return ret;
}
int lookup_mount(struct autofs_point *ap, const char *name, int name_len, void *context)
{
struct lookup_context *ctxt = (struct lookup_context *) context;
struct map_source *source;
struct mapent_cache *mc;
char *mapent = NULL;
struct mapent *me;
int ret = 1;
source = ap->entry->current;
ap->entry->current = NULL;
master_source_current_signal(ap->entry);
mc = source->mc;
/* Check if we recorded a mount fail for this key anywhere */
me = lookup_source_mapent(ap, name, LKP_DISTINCT);
if (me) {
if (me->status >= monotonic_time(NULL)) {
cache_unlock(me->mc);
return NSS_STATUS_NOTFOUND;
} else {
struct mapent_cache *smc = me->mc;
struct mapent *sme;
if (me->mapent)
cache_unlock(smc);
else {
cache_unlock(smc);
cache_writelock(smc);
sme = cache_lookup_distinct(smc, name);
/* Negative timeout expired for non-existent entry. */
if (sme && !sme->mapent) {
if (cache_pop_mapent(sme) == CHE_FAIL)
cache_delete(smc, name);
}
cache_unlock(smc);
}
}
}
/* Catch installed direct offset triggers */
cache_readlock(mc);
me = cache_lookup_distinct(mc, name);
if (!me) {
cache_unlock(mc);
/*
* If there's a '/' in the name and the offset is not in
* the cache then it's not a valid path in the mount tree.
*/
if (strchr(name, '/')) {
debug(ap->logopt,
MODPREFIX "offset %s not found", name);
return NSS_STATUS_NOTFOUND;
}
} else {
/* Otherwise we found a valid offset so try mount it */
debug(ap->logopt, MODPREFIX "%s -> %s", name, me->mapent);
/*
* If this is a request for an offset mount (whose entry
* must be present in the cache to be valid) or the entry
* is newer than the negative timeout value then just
* try and mount it. Otherwise try and remove it and
* proceed with the program map lookup.
*/
if (strchr(name, '/') ||
me->age + ap->negative_timeout > monotonic_time(NULL)) {
char *ent = NULL;
if (me->mapent) {
ent = alloca(strlen(me->mapent) + 1);
strcpy(ent, me->mapent);
}
cache_unlock(mc);
master_source_current_wait(ap->entry);
ap->entry->current = source;
ret = ctxt->parse->parse_mount(ap, name,
name_len, ent, ctxt->parse->context);
goto out_free;
} else {
if (IS_MM(me) && !IS_MM_ROOT(me)) {
cache_unlock(mc);
warn(ap->logopt, MODPREFIX
"unexpected lookup for active multi-mount"
" key %s, returning fail", name);
return NSS_STATUS_UNAVAIL;
}
cache_unlock(mc);
cache_writelock(mc);
me = cache_lookup_distinct(mc, name);
if (me) {
if (IS_MM(me))
tree_mapent_delete_offsets(mc, name);
cache_delete(mc, name);
}
cache_unlock(mc);
}
}
debug(ap->logopt, MODPREFIX "looking up %s", name);
ret = match_key(ap, source, name, name_len, &mapent, ctxt);
if (ret != NSS_STATUS_SUCCESS)
goto out_free;
debug(ap->logopt, MODPREFIX "%s -> %s", name, mapent);
master_source_current_wait(ap->entry);
ap->entry->current = source;
ret = ctxt->parse->parse_mount(ap, name, name_len,
mapent, ctxt->parse->context);
out_free:
if (mapent)
free(mapent);
if (ret) {
/* Don't update negative cache when re-connecting */
if (ap->flags & MOUNT_FLAG_REMOUNT)
return NSS_STATUS_TRYAGAIN;
cache_writelock(mc);
cache_update_negative(mc, source, name, ap->negative_timeout);
cache_unlock(mc);
return NSS_STATUS_TRYAGAIN;
}
return NSS_STATUS_SUCCESS;
}
int lookup_done(void *context)
{
struct lookup_context *ctxt = (struct lookup_context *) context;
int rv = close_parse(ctxt->parse);
if (ctxt->mapfmt)
free(ctxt->mapfmt);
free(ctxt);
return rv;
}