oskit/oskit-20020317/com/filepsid.c

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C
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2016-02-19 15:02:31 +03:00
/*
* Copyright (c) 1999 The University of Utah and the Flux Group.
* All rights reserved.
*
* Contributed by the Computer Security Research division,
* INFOSEC Research and Technology Office, NSA.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit 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 GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
#include <oskit/c/string.h>
#include <oskit/boolean.h>
#include <oskit/io/absio.h>
#include <oskit/fs/file.h>
#include <oskit/fs/dir.h>
#include <oskit/fs/openfile.h>
#include <oskit/fs/filepsid.h>
#include <oskit/com/sfs.h>
#include <oskit/com/services.h>
#include <oskit/dev/osenv.h>
#include <oskit/dev/osenv_mem.h>
#include <oskit/dev/osenv_log.h>
#include <oskit/machine/endian.h>
#include "sfs_new_hashtab.h"
#if BYTE_ORDER == LITTLE_ENDIAN
#define cpu_to_le32(x) (x)
#define le32_to_cpu(x) (x)
#define cpu_to_le64(x) (x)
#define le64_to_cpu(x) (x)
#endif
#define printf(fmt...) oskit_osenv_log_log(t->log, OSENV_LOG_INFO, ##fmt);
#if 1
#define DPRINTF(args...) printf("*** " args)
#else
#define DPRINTF(args...)
#endif
/*
* Persistent security binding directory
*/
#define PSEC_SECDIR "...security"
#define PSEC_SECDIR_MODE 0700
/*
* Persistent security binding files
*/
#define PSEC_CONTEXTS 0 /* security contexts */
#define PSEC_INDEX 1 /* psid -> (offset, len) of context */
#define PSEC_INODES 2 /* ino -> psid */
#define PSEC_NFILES 3 /* total number of security files */
static char *psec_sfiles[PSEC_NFILES] =
{
"contexts",
"index",
"inodes"
};
#define PSEC_SECFILE_MODE (OSKIT_S_IFREG | 0600)
/*
* Record structure for entries in index file.
*/
typedef struct {
oskit_off_t ofs; /* offset within file, in bytes */
oskit_u32_t len; /* length of context, in bytes */
} s_index_t;
#define SINDEX_MASK (sizeof(s_index_t)-1)
typedef oskit_u32_t psid_t;
typedef struct psidtab_node {
psid_t psid;
oskit_security_id_t sid;
struct psidtab_node *next;
} psidtab_node_t;
#define PSIDTAB_SLOTS 32
struct psidtab {
oskit_filepsid_t psidi;
unsigned count;
oskit_osenv_mem_t *mem;
oskit_osenv_log_t *log;
oskit_security_t *security;
psidtab_node_t *slots[PSIDTAB_SLOTS];
hashtab_t ino2sid;
psid_t next_psid;
oskit_file_t *files[PSEC_NFILES];
#define contexts_file absio[PSEC_CONTEXTS]
#define index_file absio[PSEC_INDEX]
#define inodes_file absio[PSEC_INODES]
oskit_absio_t *absio[PSEC_NFILES];
#define contexts_absio absio[PSEC_CONTEXTS]
#define index_absio absio[PSEC_INDEX]
#define inodes_absio absio[PSEC_INODES]
};
typedef struct psidtab psidtab_t;
#define PSIDTAB_HASH(psid) (psid & (PSIDTAB_SLOTS - 1))
#define FILE_PSID 0
#define FS_PSID 1
static oskit_error_t psidtab_create(oskit_services_t *osenv,
oskit_security_t *security,
psidtab_t **tp)
{
oskit_osenv_mem_t *mem;
oskit_osenv_log_t *log;
psidtab_t *t;
oskit_services_lookup_first(osenv, &oskit_osenv_log_iid,
(void **) &log);
if (!log)
return OSKIT_EINVAL;
oskit_services_lookup_first(osenv, &oskit_osenv_mem_iid,
(void **) &mem);
if (!mem) {
oskit_osenv_log_release(log);
return OSKIT_EINVAL;
}
t = oskit_osenv_mem_alloc(mem, sizeof(psidtab_t), 0, 0);
if (!t)
return OSKIT_ENOMEM;
memset(t, 0, sizeof(psidtab_t));
t->mem = mem;
oskit_osenv_mem_addref(mem);
t->log = log;
oskit_osenv_log_addref(log);
t->security = security;
oskit_security_addref(security);
t->ino2sid = hashtab_create(mem);
if (!t->ino2sid)
return OSKIT_ENOMEM;
*tp = t;
return 0;
}
static void psidtab_destroy(psidtab_t *t)
{
psidtab_node_t *cur, *tmp;
int hvalue, i;
oskit_osenv_mem_t *mem;
for (i = 0; i < PSEC_NFILES; i++) {
if (t->absio[i])
oskit_absio_release(t->absio[i]);
if (t->files[i]) {
oskit_file_sync(t->files[i], TRUE);
oskit_file_release(t->files[i]);
}
}
for (hvalue = 0; hvalue < PSIDTAB_SLOTS; hvalue++) {
cur = t->slots[hvalue];
while (cur) {
tmp = cur;
cur = cur->next;
oskit_osenv_mem_free(t->mem, tmp, 0,
sizeof(psidtab_node_t));
}
}
hashtab_destroy(t->ino2sid);
oskit_security_release(t->security);
oskit_osenv_log_release(t->log);
mem = t->mem;
oskit_osenv_mem_free(mem, t, 0, sizeof(psidtab_t));
oskit_osenv_mem_release(mem);
}
static int psidtab_insert(psidtab_t *t, psid_t psid, oskit_security_id_t sid)
{
psidtab_node_t *new;
int hvalue;
hvalue = PSIDTAB_HASH(psid);
new = oskit_osenv_mem_alloc(t->mem, sizeof(psidtab_node_t), 0, 0);
if (!new) {
return OSKIT_ENOMEM;
}
new->psid = psid;
new->sid = sid;
new->next = t->slots[hvalue];
t->slots[hvalue] = new;
return 0;
}
static oskit_security_id_t psidtab_search_psid(psidtab_t *t, psid_t psid)
{
psidtab_node_t *cur;
int hvalue;
hvalue = PSIDTAB_HASH(psid);
for (cur = t->slots[hvalue]; cur ; cur = cur->next) {
if (psid == cur->psid)
return cur->sid;
}
return 0;
}
static psid_t psidtab_search_sid(psidtab_t *t, oskit_security_id_t sid)
{
psidtab_node_t *cur;
int hvalue;
for (hvalue = 0; hvalue < PSIDTAB_SLOTS; hvalue++) {
for (cur = t->slots[hvalue]; cur; cur = cur->next) {
if (sid == cur->sid && cur->psid > FS_PSID)
return cur->psid;
}
}
return 0;
}
static void psidtab_change_psid(psidtab_t *t,
psid_t psid, oskit_security_id_t sid)
{
psidtab_node_t *cur;
int hvalue;
hvalue = PSIDTAB_HASH(psid);
for (cur = t->slots[hvalue]; cur ; cur = cur->next) {
if (psid == cur->psid) {
cur->sid = sid;
return;
}
}
return;
}
static oskit_error_t newpsid(psidtab_t *t,
oskit_security_id_t newsid,
psid_t *out_psid)
{
oskit_security_context_t context;
s_index_t raw_sindex;
psid_t psid;
oskit_u32_t actual, len;
oskit_off_t off, off2;
oskit_error_t rc;
DPRINTF("newpsid: obtaining psid for sid %ld\n", newsid);
rc = oskit_security_sid_to_context(t->security,
newsid, &context, &len);
if (rc)
return OSKIT_EACCES;
DPRINTF("newpsid: sid %ld -> context %s\n", newsid, context);
rc = oskit_absio_getsize(t->contexts_absio, &off);
if (rc) {
oskit_osenv_mem_free(t->mem, context, OSENV_AUTO_SIZE, 0);
return rc;
}
rc = oskit_absio_write(t->contexts_absio, context, off, len, &actual);
if (rc) {
oskit_osenv_mem_free(t->mem, context, OSENV_AUTO_SIZE, 0);
return rc;
}
if (actual != len) {
oskit_osenv_mem_free(t->mem, context, OSENV_AUTO_SIZE, 0);
return OSKIT_EIO;
}
DPRINTF("newpsid: added %s to contexts at %d\n",
context, off);
oskit_osenv_mem_free(t->mem, context, OSENV_AUTO_SIZE, 0);
raw_sindex.ofs = cpu_to_le64(off);
raw_sindex.len = cpu_to_le32(len);
psid = t->next_psid++;
off2 = psid * sizeof(s_index_t);
rc = oskit_absio_write(t->index_absio, &raw_sindex, off2,
sizeof(s_index_t), &actual);
if (rc)
return rc;
if (actual != sizeof(s_index_t))
return OSKIT_EIO;
DPRINTF("newpsid: added (%d,%d) to index at %d for new psid %d\n",
off, len, off2, psid);
rc = psidtab_insert(t, psid, newsid);
if (rc)
return rc;
DPRINTF("newpsid: added (%d, %ld) to psidtab\n", psid, newsid);
*out_psid = psid;
return 0;
}
static struct oskit_filepsid_ops filepsid_ops;
oskit_error_t
oskit_filepsid_create(oskit_dir_t * rootdir,
oskit_security_id_t fs_sid,
oskit_security_id_t file_sid,
oskit_services_t *osenv,
oskit_security_t * security,
oskit_security_id_t *out_fs_sid,
oskit_filepsid_t ** out_filepsid)
{
struct psidtab *t;
oskit_dir_t *dir = NULL;
oskit_file_t *file;
oskit_openfile_t *ofile;
oskit_u32_t index, actual, actual2;
oskit_bool_t need_to_init = FALSE;
s_index_t sindex, raw_sindex;
oskit_security_id_t sid;
psid_t file_psid, fs_psid;
char *cbuf;
oskit_error_t rc;
oskit_off_t off;
rc = psidtab_create(osenv, security, &t);
if (rc)
return rc;
t->psidi.ops = &filepsid_ops;
t->count = 1;
rc = oskit_dir_lookup(rootdir, PSEC_SECDIR, &file);
if (rc) {
if (rc != OSKIT_ENOENT) {
psidtab_destroy(t);
return rc;
}
DPRINTF("filepsid_create: %s did not exist; creating\n", PSEC_SECDIR);
rc = oskit_dir_mkdir(rootdir, PSEC_SECDIR, PSEC_SECDIR_MODE);
if (rc) {
psidtab_destroy(t);
return rc;
}
rc = oskit_dir_lookup(rootdir, PSEC_SECDIR, &file);
if (rc) {
psidtab_destroy(t);
return rc;
}
need_to_init = TRUE;
}
rc = oskit_file_query(file, &oskit_dir_iid, (void **) &dir);
oskit_file_release(file);
if (rc) {
psidtab_destroy(t);
return rc;
}
for (index = 0; index < PSEC_NFILES; index++) {
DPRINTF("filepsid_create: checking for %s\n",
psec_sfiles[index]);
rc = oskit_dir_lookup(dir, psec_sfiles[index],
&t->files[index]);
if (rc) {
if (rc != OSKIT_ENOENT) {
goto out;
}
if (!need_to_init) {
DPRINTF("filepsid_create: %s did not exist\n", psec_sfiles[index]);
goto out;
}
DPRINTF("filepsid_create: %s did not exist; creating\n",
psec_sfiles[index]);
rc = oskit_dir_create(dir, psec_sfiles[index],
FALSE, PSEC_SECFILE_MODE,
&t->files[index]);
if (rc) {
goto out;
}
}
rc = oskit_file_open(t->files[index], OSKIT_O_RDWR, &ofile);
if (rc) {
goto out;
}
rc = oskit_openfile_query(ofile, &oskit_absio_iid,
(void **) &t->absio[index]);
oskit_openfile_release(ofile);
if (rc) {
goto out;
}
}
if (need_to_init) {
DPRINTF("filepsid_create: initializing labeling files\n");
rc = newpsid(t, file_sid, &file_psid);
if (rc)
goto out;
if (file_psid) {
printf("filepsid_create: default file psid should be zero, is %d\n", file_psid);
goto out;
}
rc = newpsid(t, fs_sid, &fs_psid);
if (rc)
goto out;
if (fs_psid != FS_PSID) {
printf("filepsid_create: file system psid should be %d, is %d\n", FS_PSID, fs_psid);
goto out;
}
rc = oskit_filepsid_set(&t->psidi, (oskit_file_t *)dir,
OSKIT_SECINITSID_FILE_LABELS);
if (rc) {
printf("filepsid_create: unable to set labeling directory SID, rc 0x%x\n", rc);
goto out;
}
rc = oskit_dir_sync(dir, TRUE);
if (rc) {
printf("filepsid_create: unable to sync labeling directory, rc 0x%x\n", rc);
goto out;
}
oskit_dir_release(dir);
for (index = 0; index < PSEC_NFILES; index++) {
rc = oskit_filepsid_set(&t->psidi, t->files[index],
OSKIT_SECINITSID_FILE_LABELS);
if (rc) {
printf("filepsid_create: unable to set labeling file SID, rc 0x%x\n", rc);
goto out;
}
rc = oskit_file_sync(t->files[index], TRUE);
if (rc) {
printf("filepsid_create: unable to sync labeling file, rc 0x%x\n", rc);
goto out;
}
}
*out_fs_sid = fs_sid;
*out_filepsid = &t->psidi;
return 0;
}
DPRINTF("filepsid_create: reading existing labeling files\n");
off = 0;
rc = oskit_absio_read(t->index_absio, &raw_sindex, off,
sizeof raw_sindex, &actual);
while (!rc && (actual == sizeof raw_sindex)) {
sindex.ofs = le64_to_cpu(raw_sindex.ofs);
sindex.len = le32_to_cpu(raw_sindex.len);
DPRINTF("filepsid_create: read index (%d,%d) for psid %d\n",
sindex.ofs, sindex.len, t->next_psid);
cbuf = oskit_osenv_mem_alloc(t->mem, sindex.len, 0, 0);
if (!cbuf) {
rc = OSKIT_ENOMEM;
goto out;
}
rc = oskit_absio_read(t->contexts_absio, cbuf,
sindex.ofs, sindex.len, &actual2);
if (rc)
goto out;
if (actual2 != sindex.len) {
rc = OSKIT_EIO;
goto out;
}
rc = oskit_security_context_to_sid(t->security,
cbuf, sindex.len, &sid);
if (rc) {
DPRINTF("filepsid_create: error 0x%x in obtaining SID for context %s (psid %d), skipping.\n",
rc, cbuf, t->next_psid);
t->next_psid++;
} else {
DPRINTF("filepsid_create: psid %d -> context %s -> sid %d\n",
t->next_psid, cbuf, sid);
rc = psidtab_insert(t, t->next_psid, sid);
t->next_psid++;
if (rc)
goto out;
}
oskit_osenv_mem_free(t->mem, cbuf, 0, sindex.len);
off += sizeof raw_sindex;
rc = oskit_absio_read(t->index_absio,
&raw_sindex, off,
sizeof raw_sindex, &actual);
}
if (rc < 0) {
printf("filepsid_create: error 0x%x in reading index\n",
rc);
goto out;
}
if (actual && actual != sizeof raw_sindex) {
printf("filepsid_create: partial entry in index\n");
rc = OSKIT_EIO;
goto out;
}
fs_sid = psidtab_search_psid(t, FS_PSID);
if (!fs_sid) {
printf("filepsid_create: no SID for fs psid\n");
rc = OSKIT_EINVAL;
goto out;
}
DPRINTF("filepsid_create: fs sid %ld\n", fs_sid);
*out_fs_sid = fs_sid;
*out_filepsid = &t->psidi;
out:
if (dir)
oskit_dir_release(dir);
if (rc)
psidtab_destroy(t);
return rc;
}
/*
* oskit_filepsid methods
*/
static OSKIT_COMDECL
fpsid_query(oskit_filepsid_t * p,
const struct oskit_guid * iid,
void **out_ihandle)
{
struct psidtab *t;
t = (struct psidtab *) p;
if (memcmp(iid, &oskit_iunknown_iid, sizeof(*iid)) == 0 ||
memcmp(iid, &oskit_filepsid_iid, sizeof(*iid)) == 0) {
*out_ihandle = &t->psidi;
++t->count;
return 0;
}
*out_ihandle = NULL;
return OSKIT_E_NOINTERFACE;
}
static OSKIT_COMDECL_U
fpsid_addref(oskit_filepsid_t * p)
{
struct psidtab *t;
t = (struct psidtab *) p;
return ++t->count;
}
static OSKIT_COMDECL_U
fpsid_release(oskit_filepsid_t * p)
{
struct psidtab *t;
unsigned newcount;
t = (struct psidtab *) p;
newcount = --t->count;
if (newcount == 0) {
psidtab_destroy(t);
}
return newcount;
}
static OSKIT_COMDECL
fpsid_get(oskit_filepsid_t * p,
oskit_file_t * file,
oskit_security_id_t * outsid)
{
struct psidtab *t;
psid_t raw_psid, psid = 0;
oskit_security_id_t sid;
oskit_stat_t stats;
oskit_u32_t actual;
oskit_error_t rc;
t = (struct psidtab *) p;
rc = oskit_file_stat(file, &stats);
if (rc)
return rc;
sid = (oskit_security_id_t) hashtab_search(t->ino2sid,
(hashtab_key_t) stats.ino);
if (!sid) {
rc = oskit_absio_read(t->inodes_absio,
&raw_psid,
stats.ino * sizeof(psid_t),
sizeof(psid_t),
&actual);
if (rc)
return rc;
if (actual != sizeof(psid_t))
return OSKIT_EIO;
psid = le32_to_cpu(raw_psid);
sid = psidtab_search_psid(t, psid);
if (!sid) {
/*
* If the psid is undefined, then reset it to PSID 0.
*/
printf("psid_to_sid: no SID for psid %d\n", psid);
sid = psidtab_search_psid(t, 0);
if (!sid) {
DPRINTF("psid_to_sid: psid %d -> unlabeled\n", psid);
*outsid = OSKIT_SECINITSID_UNLABELED;
return 0;
}
DPRINTF("psid_to_sid: replacing psid %d with psid 0\n", psid);
oskit_filepsid_set(p, file, sid);
}
rc = hashtab_insert(t->ino2sid,
(hashtab_key_t) stats.ino,
(hashtab_datum_t) sid);
if (rc)
return rc;
}
*outsid = sid;
return 0;
}
static OSKIT_COMDECL
fpsid_set(oskit_filepsid_t * p,
oskit_file_t * file,
oskit_security_id_t newsid)
{
struct psidtab *t;
oskit_stat_t stats;
psid_t psid, raw_psid;
oskit_error_t rc;
oskit_u32_t actual;
t = (struct psidtab *) p;
rc = oskit_file_stat(file, &stats);
if (rc)
return rc;
psid = psidtab_search_sid(t, newsid);
if (!psid) {
rc = newpsid(t, newsid, &psid);
if (rc)
return rc;
}
raw_psid = cpu_to_le32(psid);
rc = oskit_absio_write(t->inodes_absio,
&raw_psid,
stats.ino * sizeof(psid_t),
sizeof(psid_t),
&actual);
if (rc)
return rc;
if (actual != sizeof(psid_t))
return OSKIT_EIO;
return hashtab_replace(t->ino2sid,
(hashtab_key_t) stats.ino,
(hashtab_datum_t) newsid);
}
static int chpsid(psidtab_t *t,
psid_t psid,
oskit_security_id_t newsid)
{
oskit_security_context_t context;
s_index_t raw_sindex;
psid_t clone_psid;
oskit_u32_t len, actual;
oskit_off_t off, off2;
int rc;
psidtab_node_t *cur;
int hvalue;
DPRINTF("chpsid: changing psid %d to sid %ld\n", psid, newsid);
for (hvalue = 0; hvalue < PSIDTAB_SLOTS; hvalue++) {
for (cur = t->slots[hvalue]; cur; cur = cur->next) {
if (newsid == cur->sid)
goto found;
}
}
found:
if (hvalue < PSIDTAB_SLOTS) {
clone_psid = cur->psid;
DPRINTF("chpsid: cloning existing psid %d\n", clone_psid);
off2 = clone_psid * sizeof(s_index_t);
rc = oskit_absio_read(t->index_absio,
&raw_sindex,
off2,
sizeof(s_index_t),
&actual);
if (rc < 0) {
printf("chpsid: error 0x%x in reading index\n",
rc);
return rc;
}
if (actual != sizeof(s_index_t)) {
printf("chpsid: partial entry in index\n");
return OSKIT_EIO;
}
off = le64_to_cpu(raw_sindex.ofs);
len = le32_to_cpu(raw_sindex.len);
}
else {
DPRINTF("chpsid: adding new entry to contexts\n");
rc = oskit_security_sid_to_context(t->security,
newsid, &context, &len);
if (rc)
return OSKIT_EACCES;
DPRINTF("chpsid: sid %ld -> context %s\n", newsid, context);
rc = oskit_absio_getsize(t->contexts_absio, &off);
if (rc) {
oskit_osenv_mem_free(t->mem, context, OSENV_AUTO_SIZE, 0);
return rc;
}
rc = oskit_absio_write(t->contexts_absio,
context, off, len, &actual);
if (rc < 0) {
oskit_osenv_mem_free(t->mem, context, OSENV_AUTO_SIZE, 0);
printf("chpsid: error 0x%x in writing to contexts\n", rc);
return rc;
}
if (actual != len) {
oskit_osenv_mem_free(t->mem, context, OSENV_AUTO_SIZE, 0);
printf("chpsid: partial entry in contexts\n");
return OSKIT_EIO;
}
raw_sindex.ofs = cpu_to_le64(off);
raw_sindex.len = cpu_to_le32(len);
DPRINTF("chpsid: added %s to contexts at %d\n",
context, off);
oskit_osenv_mem_free(t->mem, context, OSENV_AUTO_SIZE, 0);
}
off2 = psid * sizeof(s_index_t);
rc = oskit_absio_write(t->index_absio, &raw_sindex, off2,
sizeof(s_index_t), &actual);
if (rc < 0) {
printf("chpsid: error 0x%x in writing to index\n", rc);
return rc;
}
if (actual != sizeof(s_index_t)) {
printf("chpsid: partial write to index\n");
return OSKIT_EIO;
}
DPRINTF("chpsid: changed index at %d to (%d, %d) for psid %d\n",
off2, off, len, psid);
psidtab_change_psid(t, psid, newsid);
DPRINTF("chpsid: changed to (%d, %ld) in psidtab\n", psid, newsid);
return 0;
}
static OSKIT_COMDECL
fpsid_setfs(oskit_filepsid_t * p,
oskit_security_id_t fs_sid,
oskit_security_id_t f_sid)
{
struct psidtab *t;
int rc = 0;
t = (struct psidtab *) p;
if (fs_sid) {
rc = chpsid(t, FS_PSID, fs_sid);
}
if (f_sid && !rc) {
rc = chpsid(t, FILE_PSID, f_sid);
}
return rc;
}
static struct oskit_filepsid_ops filepsid_ops = {
fpsid_query,
fpsid_addref,
fpsid_release,
fpsid_get,
fpsid_set,
fpsid_setfs
};