Files
nfs-util/nfs-utils-2.5.2/support/nfsidmap/nss.c
2023-10-14 08:57:12 +00:00

497 lines
11 KiB
C

/*
* nss.c
*
* nsswitch idmapping functions.
*
* Copyright (c) 2004 The Regents of the University of Michigan.
* All rights reserved.
*
* J. Bruce Fields <bfields@umich.edu>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <pwd.h>
#include <grp.h>
#include <netdb.h>
#include <err.h>
#include <grp.h>
#include <limits.h>
#include <ctype.h>
#include "nfsidmap.h"
#include "nfsidmap_plugin.h"
#include "nfsidmap_private.h"
#include <syslog.h>
static char *get_default_domain(void)
{
static char default_domain[NFS4_MAX_DOMAIN_LEN] = "";
if (default_domain[0] == 0) {
nfs4_get_default_domain(NULL, default_domain, NFS4_MAX_DOMAIN_LEN);
}
return default_domain;
}
/*
* NSS Translation Methods
*
* These are all just wrappers around getpwnam and friends;
* we tack on the given domain to the results of getpwnam when looking up a uid,
* and ignore the domain entirely when looking up a name.
*/
static int write_name(char *dest, char *localname, char *domain, size_t len,
int doappend)
{
if (doappend || !strchr(localname,'@')) {
if (strlen(localname) + 1 + strlen(domain) + 1 > len)
return -ENOMEM; /* XXX: Is there an -ETOOLONG? */
strcpy(dest, localname);
strcat(dest, "@");
strcat(dest, domain);
} else {
if (strlen(localname) + 1 > len)
return -ENOMEM;
strcpy(dest, localname);
}
return 0;
}
static int nss_uid_to_name(uid_t uid, char *domain, char *name, size_t len)
{
struct passwd *pw = NULL;
struct passwd pwbuf;
char *buf;
size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
int err = -ENOMEM;
buf = malloc(buflen);
if (!buf)
goto out;
if (domain == NULL)
domain = get_default_domain();
err = -getpwuid_r(uid, &pwbuf, buf, buflen, &pw);
if (pw == NULL)
err = -ENOENT;
if (err)
goto out_buf;
if (get_nostrip() & IDTYPE_USER)
err = write_name(name, pw->pw_name, domain, len, 0);
else
err = write_name(name, pw->pw_name, domain, len, 1);
out_buf:
free(buf);
out:
return err;
}
static int nss_gid_to_name(gid_t gid, char *domain, char *name, size_t len)
{
struct group *gr = NULL;
struct group grbuf;
char *buf;
size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
int err;
if (domain == NULL)
domain = get_default_domain();
do {
err = -ENOMEM;
buf = malloc(buflen);
if (!buf)
goto out;
err = -getgrgid_r(gid, &grbuf, buf, buflen, &gr);
if (gr == NULL && !err)
err = -ENOENT;
if (err == -ERANGE) {
buflen *= 2;
free(buf);
}
} while (err == -ERANGE);
if (err)
goto out_buf;
if (get_nostrip() & IDTYPE_GROUP)
err = write_name(name, gr->gr_name, domain, len, 0);
else
err = write_name(name, gr->gr_name, domain, len, 1);
out_buf:
free(buf);
out:
return err;
}
/* XXX: actually should return error, so can distinguish between
* memory allocation failure and failure to match domain */
static char *strip_domain(const char *name, const char *domain)
{
const char *c;
char *l = NULL;
int len;
if (name == NULL)
goto out;
c = strrchr(name, '@');
if (c == NULL && domain != NULL)
goto out;
if (c == NULL && domain == NULL) {
len = strlen(name) + 1;
} else {
if (domain && strcasecmp(c + 1, domain) != 0)
goto out;
len = c - name;
}
l = malloc(len + 1);
if (l == NULL)
goto out;
memcpy(l, name, len);
l[len] = '\0';
out:
return l;
}
struct pwbuf {
struct passwd pwbuf;
char buf[1];
};
static struct passwd *nss_getpwnam(const char *name, const char *domain,
int *err_p, int dostrip)
{
struct passwd *pw;
struct pwbuf *buf;
size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
char *localname;
int err = ENOMEM;
if (buflen > UINT_MAX)
goto err;
buf = malloc(sizeof(*buf) + buflen);
if (buf == NULL)
goto err;
err = EINVAL;
if (dostrip) {
localname = strip_domain(name, domain);
IDMAP_LOG(4, ("nss_getpwnam: name '%s' domain '%s': "
"resulting localname '%s'", name, domain, localname));
if (localname == NULL) {
IDMAP_LOG(0, ("nss_getpwnam: name '%s' does not map "
"into domain '%s'", name,
domain ? domain : "<not-provided>"));
goto err_free_buf;
}
err = getpwnam_r(localname, &buf->pwbuf, buf->buf, buflen, &pw);
if (pw == NULL && domain != NULL)
IDMAP_LOG(1,
("nss_getpwnam: name '%s' not found in domain '%s'",
localname, domain));
free(localname);
} else {
err = getpwnam_r(name, &buf->pwbuf, buf->buf, buflen, &pw);
if (pw == NULL)
IDMAP_LOG(1,
("nss_getpwnam: name '%s' not found (domain not stripped)", name));
}
if (err == 0 && pw != NULL) {
*err_p = 0;
return pw;
} else if (err == 0 && pw == NULL) {
err = ENOENT;
}
err_free_buf:
free(buf);
err:
*err_p = -err;
return NULL;
}
static int nss_name_to_uid(char *name, uid_t *uid)
{
struct passwd *pw = NULL;
char *domain;
int err = -ENOENT;
domain = get_default_domain();
if (get_nostrip() & IDTYPE_USER) {
pw = nss_getpwnam(name, domain, &err, 0);
if (pw != NULL)
goto out_uid;
}
pw = nss_getpwnam(name, domain, &err, 1);
if (pw == NULL)
goto out;
out_uid:
*uid = pw->pw_uid;
IDMAP_LOG(4, ("nss_name_to_uid: name '%s' uid %u", name, *uid));
free(pw);
err = 0;
out:
return err;
}
static char *reformat_name(const char *name)
{
const char *domain;
const char *c;
const char *d;
char *l = NULL;
int len;
int dlen = 0;
int i;
c = strchr(name, '@');
if (c == NULL)
goto out;
len = c - name;
domain = ++c;
d = strchr(domain, '.');
if (d == NULL)
goto out;
dlen = d - domain;
l = malloc(dlen + 1 + len + 1);
if (l == NULL)
goto out;
for (i = 0; i < dlen; i++)
l[i] = toupper(domain[i]);
l[dlen] = '\\';
memcpy(l + dlen + 1, name, len);
l[dlen + 1 + len] = '\0';
out:
return l;
}
static int _nss_name_to_gid(char *name, gid_t *gid, int dostrip)
{
struct group *gr = NULL;
struct group grbuf;
char *buf, *domain;
size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
int err = -EINVAL;
char *localname = NULL;
char *ref_name = NULL;
domain = get_default_domain();
if (dostrip) {
localname = strip_domain(name, domain);
IDMAP_LOG(4, ("nss_name_to_gid: name '%s' domain '%s': "
"resulting localname '%s'", name, domain, localname));
if (!localname) {
IDMAP_LOG(0, ("nss_name_to_gid: name '%s' does not map "
"into domain '%s'", name, domain));
goto out;
}
} else if (get_reformat_group()) {
ref_name = reformat_name(name);
if (ref_name == NULL) {
IDMAP_LOG(1, ("nss_name_to_gid: failed to reformat name '%s'",
name));
err = -ENOENT;
goto out;
}
}
err = -ENOMEM;
if (buflen > UINT_MAX)
goto out_name;
do {
buf = malloc(buflen);
if (!buf)
goto out_name;
if (dostrip)
err = -getgrnam_r(localname, &grbuf, buf, buflen, &gr);
else if (get_reformat_group())
err = -getgrnam_r(ref_name, &grbuf, buf, buflen, &gr);
else
err = -getgrnam_r(name, &grbuf, buf, buflen, &gr);
if (gr == NULL && !err) {
if (dostrip)
IDMAP_LOG(1, ("nss_name_to_gid: name '%s' not found "
"in domain '%s'", localname, domain));
else if (get_reformat_group())
IDMAP_LOG(1, ("nss_name_to_gid: name '%s' not found "
"(reformatted)", ref_name));
else
IDMAP_LOG(1, ("nss_name_to_gid: name '%s' not found "
"(domain not stripped)", name));
err = -ENOENT;
}
if (err == -ERANGE) {
buflen *= 2;
free(buf);
}
} while (err == -ERANGE);
if (err)
goto out_buf;
*gid = gr->gr_gid;
IDMAP_LOG(4, ("nss_name_to_gid: name '%s' gid %u", name, *gid));
out_buf:
free(buf);
out_name:
if (dostrip)
free(localname);
if (get_reformat_group())
free(ref_name);
out:
return err;
}
static int nss_name_to_gid(char *name, gid_t *gid)
{
int err = 0;
if (get_nostrip() & IDTYPE_GROUP) {
err = _nss_name_to_gid(name, gid, 0);
if (!err)
goto out;
}
err = _nss_name_to_gid(name, gid, 1);
out:
return err;
}
static int nss_gss_princ_to_ids(char *secname, char *princ,
uid_t *uid, uid_t *gid,
extra_mapping_params **UNUSED(ex))
{
struct passwd *pw;
int err = 0;
char *princ_realm;
struct conf_list *realms;
struct conf_list_node *r;
int found = 0;
if (strcmp(secname, "spkm3") == 0)
return -ENOENT;
if (strcmp(secname, "krb5") != 0)
return -EINVAL;
/* get princ's realm */
princ_realm = strstr(princ, "@");
if (princ_realm == NULL)
return -EINVAL;
princ_realm++;
/* get list of "local-equivalent" realms and
* check against the principal's realm */
realms = get_local_realms();
TAILQ_FOREACH(r, &realms->fields, link) {
if (strcmp(r->field, princ_realm) == 0) {
found = 1;
break;
}
}
if (!found) {
IDMAP_LOG(1, ("nss_gss_princ_to_ids: Local-Realm '%s': NOT FOUND",
princ_realm));
return -ENOENT;
}
/* XXX: this should call something like getgssauthnam instead? */
pw = nss_getpwnam(princ, NULL, &err, 1);
if (pw == NULL) {
err = -ENOENT;
goto out;
}
*uid = pw->pw_uid;
*gid = pw->pw_gid;
free(pw);
out:
return err;
}
static int nss_gss_princ_to_grouplist(char *secname, char *princ,
gid_t *groups, int *ngroups,
extra_mapping_params **UNUSED(ex))
{
struct passwd *pw;
int ret = -EINVAL;
if (strcmp(secname, "krb5") != 0)
goto out;
/* XXX: not quite right? Need to know default realm? */
/* XXX: this should call something like getgssauthnam instead? */
pw = nss_getpwnam(princ, NULL, &ret, 1);
if (pw == NULL) {
ret = -ENOENT;
goto out;
}
if (getgrouplist(pw->pw_name, pw->pw_gid, groups, ngroups) < 0)
ret = -ERANGE;
free(pw);
out:
return ret;
}
static int nss_plugin_init(void)
{
if (nfsidmap_conf_path)
conf_init_file(nfsidmap_conf_path);
return 0;
}
/*
* Called by dlclose(). See dlopen(3) man page
*/
__attribute__((destructor))
static int nss_plugin_term(void)
{
free_local_realms();
conf_cleanup();
return 0;
}
struct trans_func nss_trans = {
.name = "nsswitch",
.init = nss_plugin_init,
.princ_to_ids = nss_gss_princ_to_ids,
.name_to_uid = nss_name_to_uid,
.name_to_gid = nss_name_to_gid,
.uid_to_name = nss_uid_to_name,
.gid_to_name = nss_gid_to_name,
.gss_princ_to_grouplist = nss_gss_princ_to_grouplist,
};
struct trans_func *libnfsidmap_plugin_init(void)
{
return (&nss_trans);
}