freebsd-dev/lib/libc/posix1e/mac.c

450 lines
9.2 KiB
C

/*
* Copyright (c) 1999, 2000, 2001, 2002 Robert N. M. Watson
* Copyright (c) 2002, 2003 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed by Robert Watson for the TrustedBSD Project.
*
* This software was developed for the FreeBSD Project in part by Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
* as part of the DARPA CHATS research program.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 AUTHOR 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/sysctl.h>
#include <dlfcn.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mac.h>
static int internal_initialized;
/*
* Maintain a list of default label preparations for various object
* types. Each name will appear only once in the list.
*
* XXXMAC: Not thread-safe.
*/
static LIST_HEAD(, label_default) label_default_head;
struct label_default {
char *ld_name;
char *ld_labels;
LIST_ENTRY(label_default) ld_entries;
};
static void
mac_destroy_labels(void)
{
struct label_default *ld;
while ((ld = LIST_FIRST(&label_default_head))) {
free(ld->ld_name);
free(ld->ld_labels);
LIST_REMOVE(ld, ld_entries);
free(ld);
}
}
static void
mac_destroy_internal(void)
{
mac_destroy_labels();
internal_initialized = 0;
}
static int
mac_add_type(const char *name, const char *labels)
{
struct label_default *ld, *ld_new;
char *name_dup, *labels_dup;
/*
* Speculatively allocate all the memory now to avoid allocating
* later when we will someday hold a mutex.
*/
name_dup = strdup(name);
if (name_dup == NULL) {
errno = ENOMEM;
return (-1);
}
labels_dup = strdup(labels);
if (labels_dup == NULL) {
free(name_dup);
errno = ENOMEM;
return (-1);
}
ld_new = malloc(sizeof(*ld));
if (ld_new == NULL) {
free(name_dup);
free(labels_dup);
errno = ENOMEM;
return (-1);
}
/*
* If the type is already present, replace the current entry
* rather than add a new instance.
*/
for (ld = LIST_FIRST(&label_default_head); ld != NULL;
ld = LIST_NEXT(ld, ld_entries)) {
if (strcmp(name, ld->ld_name) == 0)
break;
}
if (ld != NULL) {
free(ld->ld_labels);
ld->ld_labels = labels_dup;
labels_dup = NULL;
} else {
ld = ld_new;
ld->ld_name = name_dup;
ld->ld_labels = labels_dup;
ld_new = NULL;
name_dup = NULL;
labels_dup = NULL;
LIST_INSERT_HEAD(&label_default_head, ld, ld_entries);
}
if (name_dup != NULL)
free(name_dup);
if (labels_dup != NULL)
free(labels_dup);
if (ld_new != NULL)
free(ld_new);
return (0);
}
static char *
next_token(char **string)
{
char *token;
token = strsep(string, " \t");
while (token != NULL && *token == '\0')
token = strsep(string, " \t");
return (token);
}
static int
mac_init_internal(int ignore_errors)
{
const char *filename;
char line[LINE_MAX];
FILE *file;
int error;
error = 0;
LIST_INIT(&label_default_head);
if (!issetugid() && getenv("MAC_CONFFILE") != NULL)
filename = getenv("MAC_CONFFILE");
else
filename = MAC_CONFFILE;
file = fopen(filename, "re");
if (file == NULL)
return (0);
while (fgets(line, LINE_MAX, file)) {
char *comment, *parse, *statement;
if (line[strlen(line)-1] == '\n')
line[strlen(line)-1] = '\0';
else {
if (ignore_errors)
continue;
fclose(file);
error = EINVAL;
goto just_return;
}
/* Remove any comment. */
comment = line;
parse = strsep(&comment, "#");
/* Blank lines OK. */
statement = next_token(&parse);
if (statement == NULL)
continue;
if (strcmp(statement, "default_labels") == 0) {
char *name, *labels;
name = next_token(&parse);
labels = next_token(&parse);
if (name == NULL || labels == NULL ||
next_token(&parse) != NULL) {
if (ignore_errors)
continue;
error = EINVAL;
fclose(file);
goto just_return;
}
if (mac_add_type(name, labels) == -1) {
if (ignore_errors)
continue;
fclose(file);
goto just_return;
}
} else if (strcmp(statement, "default_ifnet_labels") == 0 ||
strcmp(statement, "default_file_labels") == 0 ||
strcmp(statement, "default_process_labels") == 0) {
char *labels, *type;
if (strcmp(statement, "default_ifnet_labels") == 0)
type = "ifnet";
else if (strcmp(statement, "default_file_labels") == 0)
type = "file";
else if (strcmp(statement, "default_process_labels") ==
0)
type = "process";
labels = next_token(&parse);
if (labels == NULL || next_token(&parse) != NULL) {
if (ignore_errors)
continue;
error = EINVAL;
fclose(file);
goto just_return;
}
if (mac_add_type(type, labels) == -1) {
if (ignore_errors)
continue;
fclose(file);
goto just_return;
}
} else {
if (ignore_errors)
continue;
fclose(file);
error = EINVAL;
goto just_return;
}
}
fclose(file);
internal_initialized = 1;
just_return:
if (error != 0)
mac_destroy_internal();
return (error);
}
static int
mac_maybe_init_internal(void)
{
if (!internal_initialized)
return (mac_init_internal(1));
else
return (0);
}
int
mac_reload(void)
{
if (internal_initialized)
mac_destroy_internal();
return (mac_init_internal(0));
}
int
mac_free(struct mac *mac)
{
if (mac->m_string != NULL)
free(mac->m_string);
free(mac);
return (0);
}
int
mac_from_text(struct mac **mac, const char *text)
{
*mac = (struct mac *) malloc(sizeof(**mac));
if (*mac == NULL)
return (ENOMEM);
(*mac)->m_string = strdup(text);
if ((*mac)->m_string == NULL) {
free(*mac);
*mac = NULL;
return (ENOMEM);
}
(*mac)->m_buflen = strlen((*mac)->m_string)+1;
return (0);
}
int
mac_to_text(struct mac *mac, char **text)
{
*text = strdup(mac->m_string);
if (*text == NULL)
return (ENOMEM);
return (0);
}
int
mac_prepare(struct mac **mac, const char *elements)
{
if (strlen(elements) >= MAC_MAX_LABEL_BUF_LEN)
return (EINVAL);
*mac = (struct mac *) malloc(sizeof(**mac));
if (*mac == NULL)
return (ENOMEM);
(*mac)->m_string = malloc(MAC_MAX_LABEL_BUF_LEN);
if ((*mac)->m_string == NULL) {
free(*mac);
*mac = NULL;
return (ENOMEM);
}
strcpy((*mac)->m_string, elements);
(*mac)->m_buflen = MAC_MAX_LABEL_BUF_LEN;
return (0);
}
int
mac_prepare_type(struct mac **mac, const char *name)
{
struct label_default *ld;
int error;
error = mac_maybe_init_internal();
if (error != 0)
return (error);
for (ld = LIST_FIRST(&label_default_head); ld != NULL;
ld = LIST_NEXT(ld, ld_entries)) {
if (strcmp(name, ld->ld_name) == 0)
return (mac_prepare(mac, ld->ld_labels));
}
errno = ENOENT;
return (-1); /* XXXMAC: ENOLABEL */
}
int
mac_prepare_ifnet_label(struct mac **mac)
{
return (mac_prepare_type(mac, "ifnet"));
}
int
mac_prepare_file_label(struct mac **mac)
{
return (mac_prepare_type(mac, "file"));
}
int
mac_prepare_packet_label(struct mac **mac)
{
return (mac_prepare_type(mac, "packet"));
}
int
mac_prepare_process_label(struct mac **mac)
{
return (mac_prepare_type(mac, "process"));
}
/*
* Simply test whether the TrustedBSD/MAC MIB tree is present; if so,
* return 1 to indicate that the system has MAC enabled overall or for
* a given policy.
*/
int
mac_is_present(const char *policyname)
{
int mib[5];
size_t siz;
char *mibname;
int error;
if (policyname != NULL) {
if (policyname[strcspn(policyname, ".=")] != '\0') {
errno = EINVAL;
return (-1);
}
mibname = malloc(sizeof("security.mac.") - 1 +
strlen(policyname) + sizeof(".enabled"));
if (mibname == NULL)
return (-1);
strcpy(mibname, "security.mac.");
strcat(mibname, policyname);
strcat(mibname, ".enabled");
siz = 5;
error = sysctlnametomib(mibname, mib, &siz);
free(mibname);
} else {
siz = 3;
error = sysctlnametomib("security.mac", mib, &siz);
}
if (error == -1) {
switch (errno) {
case ENOTDIR:
case ENOENT:
return (0);
default:
return (error);
}
}
return (1);
}