sss_nfs_client.c revision 2a256e4e4b64891fe846e933589506daa68aa13e
/*
SSSD
NFS Client
Copyright (C) Noam Meltzer <noam@primarydata.com> 2013-2014
Copyright (C) Noam Meltzer <tsnoam@gmail.com> 2014-
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/>.
*/
#define _GNU_SOURCE
#include <stddef.h>
#include <stdlib.h>
#include <sys/types.h>
#include <errno.h>
#include <string.h>
#include <nfsidmap.h>
#include "nfsidmap_internal.h"
#include "sss_client/sss_cli.h"
#include "sss_client/nss_mc.h"
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
#define PLUGIN_NAME "sss_nfs"
#define CONF_SECTION "sss_nfs"
#define CONF_USE_MC "memcache"
#define REPLY_ID_OFFSET (8)
#define REPLY_NAME_OFFSET (REPLY_ID_OFFSET + 8)
#define BUF_LEN (4096)
#define USE_MC_DEFAULT true
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
static char sss_nfs_plugin_name[] = PLUGIN_NAME;
static char nfs_conf_sect[] = CONF_SECTION;
static char nfs_conf_use_mc[] = CONF_USE_MC;
static bool nfs_use_mc = USE_MC_DEFAULT;
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/* Forward declarations */
static int send_recv(uint8_t **repp, size_t *rep_lenp, enum sss_cli_command cmd,
const void *req, size_t req_len);
static int reply_to_id(id_t *idp, uint8_t *rep, size_t rep_len);
static int reply_to_name(char *name, size_t len, uint8_t *rep, size_t rep_len);
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/* get from memcache functions */
static int get_uid_from_mc(id_t *uid, const char *name)
{
int rc = 0;
struct passwd pwd;
char *buf = NULL;
char *p = NULL;
size_t buflen = 0;
size_t len = 0;
if (!nfs_use_mc) {
return -1;
}
sss_strnlen(name, SSS_NAME_MAX, &len);
do {
buflen += BUF_LEN;
if ((p = realloc(buf, buflen)) == NULL) {
rc = ENOMEM;
goto done;
}
buf = p;
rc = sss_nss_mc_getpwnam(name, len, &pwd, buf, buflen);
} while (rc == ERANGE);
if (rc == 0) {
IDMAP_LOG(1, ("found user %s in memcache", name));
*uid = pwd.pw_uid;
} else {
IDMAP_LOG(1, ("user %s not in memcache", name));
}
done:
free(buf);
return rc;
}
static int get_gid_from_mc(id_t *gid, const char *name)
{
int rc = 0;
struct group grp;
char *buf = NULL;
char *p = NULL;
size_t buflen = 0;
size_t len;
if (!nfs_use_mc) {
return -1;
}
sss_strnlen(name, SSS_NAME_MAX, &len);
do {
buflen += BUF_LEN;
if ((p = realloc(buf, buflen)) == NULL) {
rc = ENOMEM;
goto done;
}
buf = p;
rc = sss_nss_mc_getgrnam(name, len, &grp, buf, buflen);
} while (rc == ERANGE);
if (rc == 0) {
IDMAP_LOG(1, ("found group %s in memcache", name));
*gid = grp.gr_gid;
} else {
IDMAP_LOG(1, ("group %s not in memcache", name));
}
done:
free(buf);
return rc;
}
static int get_user_from_mc(char *name, size_t len, uid_t uid)
{
int rc;
struct passwd pwd;
char *buf = NULL;
char *p = NULL;
size_t buflen = 0;
size_t pw_name_len;
if (!nfs_use_mc) {
return -1;
}
do {
buflen += BUF_LEN;
if ((p = realloc(buf, buflen)) == NULL) {
rc = ENOMEM;
goto done;
}
buf = p;
rc = sss_nss_mc_getpwuid(uid, &pwd, buf, buflen);
} while (rc == ERANGE);
if (rc == 0) {
pw_name_len = strlen(pwd.pw_name) + 1;
if (pw_name_len > len) {
IDMAP_LOG(0, ("%s: reply too long; pw_name_len=%lu, len=%lu",
__func__, pw_name_len, len));
rc = ENOBUFS;
}
IDMAP_LOG(1, ("found uid %i in memcache", uid));
memcpy(name, pwd.pw_name, pw_name_len);
} else {
IDMAP_LOG(1, ("uid %i not in memcache", uid));
}
done:
free(buf);
return rc;
}
static int get_group_from_mc(char *name, size_t len, id_t gid)
{
int rc;
struct group grp;
char *buf = NULL;
char *p = NULL;
size_t buflen = 0;
size_t gr_name_len;
if (!nfs_use_mc) {
return -1;
}
do {
buflen += BUF_LEN;
if ((p = realloc(buf, buflen)) == NULL) {
rc = ENOMEM;
goto done;
}
buf = p;
rc = sss_nss_mc_getgrgid(gid, &grp, buf, buflen);
} while (rc == ERANGE);
if (rc == 0) {
gr_name_len = strlen(grp.gr_name) + 1;
if (gr_name_len > len) {
IDMAP_LOG(0, ("%s: reply too long; gr_name_len=%lu, len=%lu",
__func__, gr_name_len, len));
rc = ENOBUFS;
}
IDMAP_LOG(1, ("found gid %i in memcache", gid));
memcpy(name, grp.gr_name, gr_name_len);
} else {
IDMAP_LOG(1, ("gid %i not in memcache", gid));
}
done:
free(buf);
return rc;
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
static int name_to_id(const char *name, id_t *id, enum sss_cli_command cmd)
{
int rc;
uint8_t *rep = NULL;
size_t rep_len = 0;
size_t name_len;
sss_strnlen(name, SSS_NAME_MAX, &name_len);
rc = send_recv(&rep, &rep_len, cmd, name, name_len + 1);
if (rc == 0) {
rc = reply_to_id(id, rep, rep_len);
}
free(rep);
return rc;
}
static int id_to_name(char *name, size_t len, id_t id,
enum sss_cli_command cmd)
{
int rc;
size_t rep_len = 0;
size_t req_len = sizeof(id_t);
uint8_t *rep = NULL;
uint8_t req[req_len];
memcpy(req, &id, req_len);
rc = send_recv(&rep, &rep_len, cmd, &req, req_len);
if (rc == 0) {
rc = reply_to_name(name, len, rep, rep_len);
}
free(rep);
return rc;
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
static int send_recv(uint8_t **rep, size_t *rep_len, enum sss_cli_command cmd,
const void *req, size_t req_len)
{
int err = 0;
enum nss_status req_rc;
struct sss_cli_req_data rd;
rd.data = req;
rd.len = req_len;
sss_nss_lock();
req_rc = sss_nss_make_request(cmd, &rd, rep, rep_len, &err);
sss_nss_unlock();
if (req_rc == NSS_STATUS_NOTFOUND) {
return ENOENT;
}
if (req_rc != NSS_STATUS_SUCCESS) {
IDMAP_LOG(0, ("no-make-request; err=%i", err));
return EPIPE;
}
return 0;
}
static int reply_to_id(id_t *idp, uint8_t *rep, size_t rep_len)
{
int rc = 0;
id_t id;
uint32_t num_results = 0;
if (rep_len < sizeof(uint32_t)) {
IDMAP_LOG(0, ("%s: reply too small; rep_len=%lu", __func__, rep_len));
rc = EBADMSG;
goto done;
}
SAFEALIGN_COPY_UINT32(&num_results, rep, NULL);
if (num_results > 1) {
IDMAP_LOG(0, ("%s: too many results (%lu)", __func__, num_results));
rc = EBADMSG;
goto done;
}
if (num_results == 0) {
rc = ENOENT;
goto done;
}
if (rep_len < sizeof(uint32_t) + REPLY_ID_OFFSET) {
IDMAP_LOG(0, ("%s: reply too small(2); rep_len=%lu", __func__,
rep_len));
rc = EBADMSG;
goto done;
}
SAFEALIGN_COPY_UINT32(&id, rep + REPLY_ID_OFFSET, NULL);
*idp = id;
done:
return rc;
}
static int reply_to_name(char *name, size_t len, uint8_t *rep, size_t rep_len)
{
int rc = 0;
uint32_t num_results = 0;
const char *buf;
size_t buf_len;
size_t offset;
if (rep_len < sizeof(uint32_t)) {
IDMAP_LOG(0, ("%s: reply too small; rep_len=%lu", __func__, rep_len));
rc = EBADMSG;
goto done;
}
SAFEALIGN_COPY_UINT32(&num_results, rep, NULL);
if (num_results > 1) {
IDMAP_LOG(0, ("%s: too many results (%lu)", __func__, num_results));
rc = EBADMSG;
goto done;
}
if (num_results == 0) {
rc = ENOENT;
goto done;
}
if (rep_len < sizeof(uint32_t) + REPLY_NAME_OFFSET) {
IDMAP_LOG(0, ("%s: reply too small(2); rep_len=%lu", __func__,
rep_len));
rc = EBADMSG;
goto done;
}
buf = (const char *)(rep + REPLY_NAME_OFFSET);
buf_len = rep_len - REPLY_NAME_OFFSET;
offset = 0;
rc = sss_readrep_copy_string(buf, &offset, &buf_len, &len, &name, NULL);
if (rc != 0) {
rc = -rc;
}
done:
return rc;
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/* configuration parsing aids */
static bool str_equal(const char *s1, const char *s2)
{
bool res = false;
size_t len1;
size_t len2;
len1 = strlen(s1);
len2 = strlen(s2);
if (len1 == len2) {
res = (strncasecmp(s1, s2, len1) == 0);
}
return res;
}
static int nfs_conf_get_bool(char *sect, char *attr, int def)
{
int res;
char *val;
res = def;
val = conf_get_str(sect, attr);
if (val) {
res = (str_equal("1", val) ||
str_equal("yes", val) ||
str_equal("true", val) ||
str_equal("on", val));
}
return res;
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/* libnfsidmap return-code aids */
/*
* we only want to return 0 or ENOENT; otherwise libnfsidmap will stop
* translation instead of proceeding to the next translation plugin
*/
int normalise_rc(int rc) {
int res;
res = rc;
if (res != 0 && res != ENOENT) {
res = ENOENT;
}
return res;
}
/* log the actual rc from our code (to be used before normalising the rc) */
void log_actual_rc(const char *trans_name, int rc) {
char tmp[80];
IDMAP_LOG(1, ("%s: rc=%i msg=%s", trans_name, rc,
strerror_r(rc, tmp, sizeof(tmp))));
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/* The external interface */
static int sss_nfs_init(void)
{
nfs_use_mc = nfs_conf_get_bool(nfs_conf_sect, nfs_conf_use_mc,
USE_MC_DEFAULT);
IDMAP_LOG(1, ("%s: use memcache: %i", __func__, nfs_use_mc));
return 0;
}
static int sss_nfs_princ_to_ids(char *secname, char *princ, uid_t *uid,
gid_t *gid, extra_mapping_params **ex)
{
IDMAP_LOG(0, ("%s: not implemented", __func__));
return -ENOENT;
}
static int sss_nfs_name_to_uid(char *name, uid_t *uid)
{
int rc;
size_t name_len = 0;
if (name == NULL) {
IDMAP_LOG(0, ("%s: name is null", __func__));
return -EINVAL;
}
if (uid == NULL) {
IDMAP_LOG(0, ("%s: uid is null", __func__));
return -EINVAL;
}
rc = sss_strnlen(name, SSS_NAME_MAX, &name_len);
if (rc != 0) {
IDMAP_LOG(0, ("%s: no-strnlen; rc=%i", __func__, rc));
return -rc;
}
rc = get_uid_from_mc(uid, name);
if (rc != 0) {
rc = name_to_id(name, uid, SSS_NSS_GETPWNAM);
}
log_actual_rc(__func__, rc);
rc = normalise_rc(rc);
return -rc;
}
static int sss_nfs_name_to_gid(char *name, gid_t *gid)
{
int rc;
size_t name_len = 0;
if (name == NULL) {
IDMAP_LOG(0, ("%s: name is null", __func__));
return -EINVAL;
}
if (gid == NULL) {
IDMAP_LOG(0, ("%s: gid is null", __func__));
return -EINVAL;
}
rc = sss_strnlen(name, SSS_NAME_MAX, &name_len);
if (rc != 0) {
IDMAP_LOG(0, ("%s: no-strnlen; rc=%i", __func__, rc));
return -rc;
}
rc = get_gid_from_mc(gid, name);
if (rc != 0) {
rc = name_to_id(name, gid, SSS_NSS_GETGRNAM);
}
log_actual_rc(__func__, rc);
rc = normalise_rc(rc);
return -rc;
}
static int sss_nfs_uid_to_name(uid_t uid, char *domain, char *name, size_t len)
{
int rc;
if (name == NULL) {
IDMAP_LOG(0, ("%s: name is null", __func__));
return -EINVAL;
}
rc = get_user_from_mc(name, len, uid);
if (rc != 0) {
rc = id_to_name(name, len, uid, SSS_NSS_GETPWUID);
}
log_actual_rc(__func__, rc);
rc = normalise_rc(rc);
return -rc;
}
static int sss_nfs_gid_to_name(gid_t gid, char *domain, char *name, size_t len)
{
int rc;
if (name == NULL) {
IDMAP_LOG(0, ("%s: name is null", __func__));
return -EINVAL;
}
rc = get_group_from_mc(name, len, gid);
if (rc != 0) {
rc = id_to_name(name, len, gid, SSS_NSS_GETGRGID);
}
log_actual_rc(__func__, rc);
rc = normalise_rc(rc);
return -rc;
}
static int sss_nfs_gss_princ_to_grouplist(
char *secname, char *princ, gid_t *groups, int *ngroups,
extra_mapping_params **ex)
{
IDMAP_LOG(0, ("%s: not implemented", __func__));
return -ENOENT;
}
static struct trans_func s_sss_nfs_trans = {
.name = sss_nfs_plugin_name,
.init = sss_nfs_init,
.princ_to_ids = sss_nfs_princ_to_ids,
.name_to_uid = sss_nfs_name_to_uid,
.name_to_gid = sss_nfs_name_to_gid,
.uid_to_name = sss_nfs_uid_to_name,
.gid_to_name = sss_nfs_gid_to_name,
.gss_princ_to_grouplist = sss_nfs_gss_princ_to_grouplist,
};
struct trans_func *libnfsidmap_plugin_init(void)
{
return (&s_sss_nfs_trans);
}