blob: fd3e01300df6b3f63093098bf54c30ce777183be [file] [log] [blame]
/*
* File contexts backend for labeling system
*
* Author : Eamon Walsh <ewalsh@tycho.nsa.gov>
* Author : Stephen Smalley <sds@tycho.nsa.gov>
*/
#include <assert.h>
#include <fcntl.h>
#include <stdarg.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stdint.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "callbacks.h"
#include "label_internal.h"
#include "label_file.h"
/*
* Internals, mostly moved over from matchpathcon.c
*/
/* return the length of the text that is the stem of a file name */
static int get_stem_from_file_name(const char *const buf)
{
const char *tmp = strchr(buf + 1, '/');
if (!tmp)
return 0;
return tmp - buf;
}
/* find the stem of a file name, returns the index into stem_arr (or -1 if
* there is no match - IE for a file in the root directory or a regex that is
* too complex for us). */
static int find_stem_from_file(struct saved_data *data, const char *key)
{
int i;
int stem_len = get_stem_from_file_name(key);
if (!stem_len)
return -1;
for (i = 0; i < data->num_stems; i++) {
if (stem_len == data->stem_arr[i].len
&& !strncmp(key, data->stem_arr[i].buf, stem_len)) {
return i;
}
}
return -1;
}
/*
* Warn about duplicate specifications.
*/
static int nodups_specs(struct saved_data *data, const char *path)
{
int rc = 0;
unsigned int ii, jj;
struct spec *curr_spec, *spec_arr = data->spec_arr;
for (ii = 0; ii < data->nspec; ii++) {
curr_spec = &spec_arr[ii];
for (jj = ii + 1; jj < data->nspec; jj++) {
if ((!strcmp(spec_arr[jj].regex_str,
curr_spec->regex_str))
&& (!spec_arr[jj].mode || !curr_spec->mode
|| spec_arr[jj].mode == curr_spec->mode)) {
rc = -1;
errno = EINVAL;
if (strcmp(spec_arr[jj].lr.ctx_raw,
curr_spec->lr.ctx_raw)) {
COMPAT_LOG
(SELINUX_ERROR,
"%s: Multiple different specifications for %s (%s and %s).\n",
path, curr_spec->regex_str,
spec_arr[jj].lr.ctx_raw,
curr_spec->lr.ctx_raw);
} else {
COMPAT_LOG
(SELINUX_ERROR,
"%s: Multiple same specifications for %s.\n",
path, curr_spec->regex_str);
}
}
}
}
return rc;
}
static int process_text_file(FILE *fp, const char *prefix,
struct selabel_handle *rec, const char *path)
{
int rc;
size_t line_len;
unsigned int lineno = 0;
char *line_buf = NULL;
while (getline(&line_buf, &line_len, fp) > 0) {
rc = process_line(rec, path, prefix, line_buf, ++lineno);
if (rc)
goto out;
}
rc = 0;
out:
free(line_buf);
return rc;
}
static int load_mmap(FILE *fp, size_t len, struct selabel_handle *rec,
const char *path)
{
struct saved_data *data = (struct saved_data *)rec->data;
int rc;
char *addr, *str_buf;
int *stem_map;
struct mmap_area *mmap_area;
uint32_t i, magic, version;
uint32_t entry_len, stem_map_len, regex_array_len;
const char *reg_version;
const char *reg_arch;
char reg_arch_matches = 0;
mmap_area = malloc(sizeof(*mmap_area));
if (!mmap_area) {
return -1;
}
addr = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fileno(fp), 0);
if (addr == MAP_FAILED) {
free(mmap_area);
perror("mmap");
return -1;
}
/* save where we mmap'd the file to cleanup on close() */
mmap_area->addr = mmap_area->next_addr = addr;
mmap_area->len = mmap_area->next_len = len;
mmap_area->next = data->mmap_areas;
data->mmap_areas = mmap_area;
/* check if this looks like an fcontext file */
rc = next_entry(&magic, mmap_area, sizeof(uint32_t));
if (rc < 0 || magic != SELINUX_MAGIC_COMPILED_FCONTEXT)
return -1;
/* check if this version is higher than we understand */
rc = next_entry(&version, mmap_area, sizeof(uint32_t));
if (rc < 0 || version > SELINUX_COMPILED_FCONTEXT_MAX_VERS)
return -1;
reg_version = regex_version();
if (!reg_version)
return -1;
reg_arch = regex_arch_string();
if (!reg_arch)
return -1;
if (version >= SELINUX_COMPILED_FCONTEXT_PCRE_VERS) {
len = strlen(reg_version);
rc = next_entry(&entry_len, mmap_area, sizeof(uint32_t));
if (rc < 0)
return -1;
/* Check version lengths */
if (len != entry_len)
return -1;
/* Check if regex version mismatch */
str_buf = malloc(entry_len + 1);
if (!str_buf)
return -1;
rc = next_entry(str_buf, mmap_area, entry_len);
if (rc < 0) {
free(str_buf);
return -1;
}
str_buf[entry_len] = '\0';
if ((strcmp(str_buf, reg_version) != 0)) {
free(str_buf);
return -1;
}
free(str_buf);
if (version >= SELINUX_COMPILED_FCONTEXT_REGEX_ARCH) {
len = strlen(reg_arch);
rc = next_entry(&entry_len, mmap_area,
sizeof(uint32_t));
if (rc < 0)
return -1;
/* Check arch string lengths */
if (len != entry_len) {
/*
* Skip the entry and conclude that we have
* a mismatch, which is not fatal.
*/
next_entry(NULL, mmap_area, entry_len);
goto end_arch_check;
}
/* Check if arch string mismatch */
str_buf = malloc(entry_len + 1);
if (!str_buf)
return -1;
rc = next_entry(str_buf, mmap_area, entry_len);
if (rc < 0) {
free(str_buf);
return -1;
}
str_buf[entry_len] = '\0';
reg_arch_matches = strcmp(str_buf, reg_arch) == 0;
free(str_buf);
}
}
end_arch_check:
/* allocate the stems_data array */
rc = next_entry(&stem_map_len, mmap_area, sizeof(uint32_t));
if (rc < 0)
return -1;
/*
* map indexed by the stem # in the mmap file and contains the stem
* number in the data stem_arr
*/
stem_map = calloc(stem_map_len, sizeof(*stem_map));
if (!stem_map)
return -1;
for (i = 0; i < stem_map_len; i++) {
char *buf;
uint32_t stem_len;
int newid;
/* the length does not inlude the nul */
rc = next_entry(&stem_len, mmap_area, sizeof(uint32_t));
if (rc < 0 || !stem_len) {
rc = -1;
goto out;
}
/* Check for stem_len wrap around. */
if (stem_len < UINT32_MAX) {
buf = (char *)mmap_area->next_addr;
/* Check if over-run before null check. */
rc = next_entry(NULL, mmap_area, (stem_len + 1));
if (rc < 0)
goto out;
if (buf[stem_len] != '\0') {
rc = -1;
goto out;
}
} else {
rc = -1;
goto out;
}
/* store the mapping between old and new */
newid = find_stem(data, buf, stem_len);
if (newid < 0) {
newid = store_stem(data, buf, stem_len);
if (newid < 0) {
rc = newid;
goto out;
}
data->stem_arr[newid].from_mmap = 1;
}
stem_map[i] = newid;
}
/* allocate the regex array */
rc = next_entry(&regex_array_len, mmap_area, sizeof(uint32_t));
if (rc < 0 || !regex_array_len) {
rc = -1;
goto out;
}
for (i = 0; i < regex_array_len; i++) {
struct spec *spec;
int32_t stem_id, meta_chars;
uint32_t mode = 0, prefix_len = 0;
rc = grow_specs(data);
if (rc < 0)
goto out;
spec = &data->spec_arr[data->nspec];
spec->from_mmap = 1;
/* Process context */
rc = next_entry(&entry_len, mmap_area, sizeof(uint32_t));
if (rc < 0 || !entry_len) {
rc = -1;
goto out;
}
str_buf = malloc(entry_len);
if (!str_buf) {
rc = -1;
goto out;
}
rc = next_entry(str_buf, mmap_area, entry_len);
if (rc < 0) {
free(str_buf);
goto out;
}
if (str_buf[entry_len - 1] != '\0') {
free(str_buf);
rc = -1;
goto out;
}
spec->lr.ctx_raw = str_buf;
if (strcmp(spec->lr.ctx_raw, "<<none>>") && rec->validating) {
if (selabel_validate(rec, &spec->lr) < 0) {
selinux_log(SELINUX_ERROR,
"%s: context %s is invalid\n",
path, spec->lr.ctx_raw);
goto out;
}
}
/* Process regex string */
rc = next_entry(&entry_len, mmap_area, sizeof(uint32_t));
if (rc < 0 || !entry_len) {
rc = -1;
goto out;
}
spec->regex_str = (char *)mmap_area->next_addr;
rc = next_entry(NULL, mmap_area, entry_len);
if (rc < 0)
goto out;
if (spec->regex_str[entry_len - 1] != '\0') {
rc = -1;
goto out;
}
/* Process mode */
if (version >= SELINUX_COMPILED_FCONTEXT_MODE)
rc = next_entry(&mode, mmap_area, sizeof(uint32_t));
else
rc = next_entry(&mode, mmap_area, sizeof(mode_t));
if (rc < 0)
goto out;
spec->mode = mode;
/* map the stem id from the mmap file to the data->stem_arr */
rc = next_entry(&stem_id, mmap_area, sizeof(int32_t));
if (rc < 0)
goto out;
if (stem_id < 0 || stem_id >= (int32_t)stem_map_len)
spec->stem_id = -1;
else
spec->stem_id = stem_map[stem_id];
/* retrieve the hasMetaChars bit */
rc = next_entry(&meta_chars, mmap_area, sizeof(uint32_t));
if (rc < 0)
goto out;
spec->hasMetaChars = meta_chars;
/* and prefix length for use by selabel_lookup_best_match */
if (version >= SELINUX_COMPILED_FCONTEXT_PREFIX_LEN) {
rc = next_entry(&prefix_len, mmap_area,
sizeof(uint32_t));
if (rc < 0)
goto out;
spec->prefix_len = prefix_len;
}
rc = regex_load_mmap(mmap_area, &spec->regex, reg_arch_matches,
&spec->regex_compiled);
if (rc < 0)
goto out;
__pthread_mutex_init(&spec->regex_lock, NULL);
data->nspec++;
}
rc = 0;
out:
free(stem_map);
return rc;
}
struct file_details {
const char *suffix;
struct stat sb;
};
static char *rolling_append(char *current, const char *suffix, size_t max)
{
size_t size;
size_t suffix_size;
size_t current_size;
if (!suffix)
return current;
current_size = strlen(current);
suffix_size = strlen(suffix);
size = current_size + suffix_size;
if (size < current_size || size < suffix_size)
return NULL;
/* ensure space for the '.' and the '\0' characters. */
if (size >= (SIZE_MAX - 2))
return NULL;
size += 2;
if (size > max)
return NULL;
/* Append any given suffix */
char *to = current + current_size;
*to++ = '.';
strcpy(to, suffix);
return current;
}
static bool fcontext_is_binary(FILE *fp)
{
uint32_t magic;
size_t len = fread(&magic, sizeof(magic), 1, fp);
rewind(fp);
return (len && (magic == SELINUX_MAGIC_COMPILED_FCONTEXT));
}
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
static FILE *open_file(const char *path, const char *suffix,
char *save_path, size_t len, struct stat *sb, bool open_oldest)
{
unsigned int i;
int rc;
char stack_path[len];
struct file_details *found = NULL;
/*
* Rolling append of suffix. Try to open with path.suffix then the
* next as path.suffix.suffix and so forth.
*/
struct file_details fdetails[2] = {
{ .suffix = suffix },
{ .suffix = "bin" }
};
rc = snprintf(stack_path, sizeof(stack_path), "%s", path);
if (rc >= (int) sizeof(stack_path)) {
errno = ENAMETOOLONG;
return NULL;
}
for (i = 0; i < ARRAY_SIZE(fdetails); i++) {
/* This handles the case if suffix is null */
path = rolling_append(stack_path, fdetails[i].suffix,
sizeof(stack_path));
if (!path)
return NULL;
rc = stat(path, &fdetails[i].sb);
if (rc)
continue;
/* first file thing found, just take it */
if (!found) {
strcpy(save_path, path);
found = &fdetails[i];
continue;
}
/*
* Keep picking the newest file found. Where "newest"
* includes equality. This provides a precedence on
* secondary suffixes even when the timestamp is the
* same. Ie choose file_contexts.bin over file_contexts
* even if the time stamp is the same. Invert this logic
* on open_oldest set to true. The idea is that if the
* newest file failed to process, we can attempt to
* process the oldest. The logic here is subtle and depends
* on the array ordering in fdetails for the case when time
* stamps are the same.
*/
if (open_oldest ^
(fdetails[i].sb.st_mtime >= found->sb.st_mtime)) {
found = &fdetails[i];
strcpy(save_path, path);
}
}
if (!found) {
errno = ENOENT;
return NULL;
}
memcpy(sb, &found->sb, sizeof(*sb));
return fopen(save_path, "re");
}
static int process_file(const char *path, const char *suffix,
struct selabel_handle *rec,
const char *prefix, struct selabel_digest *digest)
{
int rc;
unsigned int i;
struct stat sb;
FILE *fp = NULL;
char found_path[PATH_MAX];
/*
* On the first pass open the newest modified file. If it fails to
* process, then the second pass shall open the oldest file. If both
* passes fail, then it's a fatal error.
*/
for (i = 0; i < 2; i++) {
fp = open_file(path, suffix, found_path, sizeof(found_path),
&sb, i > 0);
if (fp == NULL)
return -1;
rc = fcontext_is_binary(fp) ?
load_mmap(fp, sb.st_size, rec, found_path) :
process_text_file(fp, prefix, rec, found_path);
if (!rc)
rc = digest_add_specfile(digest, fp, NULL, sb.st_size,
found_path);
fclose(fp);
if (!rc)
return 0;
}
return -1;
}
static void selabel_subs_fini(struct selabel_sub *ptr)
{
struct selabel_sub *next;
while (ptr) {
next = ptr->next;
free(ptr->src);
free(ptr->dst);
free(ptr);
ptr = next;
}
}
static char *selabel_sub(struct selabel_sub *ptr, const char *src)
{
char *dst = NULL;
int len;
while (ptr) {
if (strncmp(src, ptr->src, ptr->slen) == 0 ) {
if (src[ptr->slen] == '/' ||
src[ptr->slen] == 0) {
if ((src[ptr->slen] == '/') &&
(strcmp(ptr->dst, "/") == 0))
len = ptr->slen + 1;
else
len = ptr->slen;
if (asprintf(&dst, "%s%s", ptr->dst, &src[len]) < 0)
return NULL;
return dst;
}
}
ptr = ptr->next;
}
return NULL;
}
#if !defined(BUILD_HOST) && !defined(ANDROID)
static int selabel_subs_init(const char *path, struct selabel_digest *digest,
struct selabel_sub **out_subs)
{
char buf[1024];
FILE *cfg = fopen(path, "re");
struct selabel_sub *list = NULL, *sub = NULL;
struct stat sb;
int status = -1;
*out_subs = NULL;
if (!cfg) {
/* If the file does not exist, it is not fatal */
return (errno == ENOENT) ? 0 : -1;
}
if (fstat(fileno(cfg), &sb) < 0)
goto out;
while (fgets_unlocked(buf, sizeof(buf) - 1, cfg)) {
char *ptr = NULL;
char *src = buf;
char *dst = NULL;
while (*src && isspace(*src))
src++;
if (src[0] == '#') continue;
ptr = src;
while (*ptr && ! isspace(*ptr))
ptr++;
*ptr++ = '\0';
if (! *src) continue;
dst = ptr;
while (*dst && isspace(*dst))
dst++;
ptr=dst;
while (*ptr && ! isspace(*ptr))
ptr++;
*ptr='\0';
if (! *dst)
continue;
sub = malloc(sizeof(*sub));
if (! sub)
goto err;
memset(sub, 0, sizeof(*sub));
sub->src=strdup(src);
if (! sub->src)
goto err;
sub->dst=strdup(dst);
if (! sub->dst)
goto err;
sub->slen = strlen(src);
sub->next = list;
list = sub;
sub = NULL;
}
if (digest_add_specfile(digest, cfg, NULL, sb.st_size, path) < 0)
goto err;
*out_subs = list;
status = 0;
out:
fclose(cfg);
return status;
err:
if (sub)
free(sub->src);
free(sub);
while (list) {
sub = list->next;
free(list->src);
free(list->dst);
free(list);
list = sub;
}
goto out;
}
#endif
static char *selabel_sub_key(struct saved_data *data, const char *key)
{
char *ptr = NULL;
char *dptr = NULL;
ptr = selabel_sub(data->subs, key);
if (ptr) {
dptr = selabel_sub(data->dist_subs, ptr);
if (dptr) {
free(ptr);
ptr = dptr;
}
} else {
ptr = selabel_sub(data->dist_subs, key);
}
if (ptr)
return ptr;
return NULL;
}
static void closef(struct selabel_handle *rec);
static int init(struct selabel_handle *rec, const struct selinux_opt *opts,
unsigned n)
{
struct saved_data *data = (struct saved_data *)rec->data;
size_t num_paths = 0;
char **path = NULL;
const char *prefix = NULL;
int status = -1;
size_t i;
bool baseonly = false;
bool path_provided;
/* Process arguments */
i = n;
while (i--)
switch(opts[i].type) {
case SELABEL_OPT_PATH:
num_paths++;
break;
case SELABEL_OPT_SUBSET:
prefix = opts[i].value;
break;
case SELABEL_OPT_BASEONLY:
baseonly = !!opts[i].value;
break;
}
if (!num_paths) {
num_paths = 1;
path_provided = false;
} else {
path_provided = true;
}
path = calloc(num_paths, sizeof(*path));
if (path == NULL) {
goto finish;
}
rec->spec_files = path;
rec->spec_files_len = num_paths;
if (path_provided) {
for (i = 0; i < n; i++) {
switch(opts[i].type) {
case SELABEL_OPT_PATH:
*path = strdup(opts[i].value);
if (*path == NULL)
goto finish;
path++;
break;
default:
break;
}
}
}
#if !defined(BUILD_HOST) && !defined(ANDROID)
char subs_file[PATH_MAX + 1];
/* Process local and distribution substitution files */
if (!path_provided) {
status = selabel_subs_init(
selinux_file_context_subs_dist_path(),
rec->digest, &data->dist_subs);
if (status)
goto finish;
status = selabel_subs_init(selinux_file_context_subs_path(),
rec->digest, &data->subs);
if (status)
goto finish;
rec->spec_files[0] = strdup(selinux_file_context_path());
if (rec->spec_files[0] == NULL)
goto finish;
} else {
for (i = 0; i < num_paths; i++) {
snprintf(subs_file, sizeof(subs_file), "%s.subs_dist", rec->spec_files[i]);
status = selabel_subs_init(subs_file, rec->digest,
&data->dist_subs);
if (status)
goto finish;
snprintf(subs_file, sizeof(subs_file), "%s.subs", rec->spec_files[i]);
status = selabel_subs_init(subs_file, rec->digest,
&data->subs);
if (status)
goto finish;
}
}
#else
if (!path_provided) {
selinux_log(SELINUX_ERROR, "No path given to file labeling backend\n");
goto finish;
}
#endif
/*
* Do detailed validation of the input and fill the spec array
*/
for (i = 0; i < num_paths; i++) {
status = process_file(rec->spec_files[i], NULL, rec, prefix, rec->digest);
if (status)
goto finish;
if (rec->validating) {
status = nodups_specs(data, rec->spec_files[i]);
if (status)
goto finish;
}
}
if (!baseonly) {
status = process_file(rec->spec_files[0], "homedirs", rec, prefix,
rec->digest);
if (status && errno != ENOENT)
goto finish;
status = process_file(rec->spec_files[0], "local", rec, prefix,
rec->digest);
if (status && errno != ENOENT)
goto finish;
}
digest_gen_hash(rec->digest);
status = sort_specs(data);
finish:
if (status)
closef(rec);
return status;
}
/*
* Backend interface routines
*/
static void closef(struct selabel_handle *rec)
{
struct saved_data *data = (struct saved_data *)rec->data;
struct mmap_area *area, *last_area;
struct spec *spec;
struct stem *stem;
unsigned int i;
if (!data)
return;
/* make sure successive ->func_close() calls are harmless */
rec->data = NULL;
selabel_subs_fini(data->subs);
selabel_subs_fini(data->dist_subs);
for (i = 0; i < data->nspec; i++) {
spec = &data->spec_arr[i];
free(spec->lr.ctx_trans);
free(spec->lr.ctx_raw);
regex_data_free(spec->regex);
__pthread_mutex_destroy(&spec->regex_lock);
if (spec->from_mmap)
continue;
free(spec->regex_str);
free(spec->type_str);
}
for (i = 0; i < (unsigned int)data->num_stems; i++) {
stem = &data->stem_arr[i];
if (stem->from_mmap)
continue;
free(stem->buf);
}
if (data->spec_arr)
free(data->spec_arr);
if (data->stem_arr)
free(data->stem_arr);
area = data->mmap_areas;
while (area) {
munmap(area->addr, area->len);
last_area = area;
area = area->next;
free(last_area);
}
free(data);
}
// Finds all the matches of |key| in the given context. Returns the result in
// the allocated array and updates the match count. If match_count is NULL,
// stops early once the 1st match is found.
static const struct spec **lookup_all(struct selabel_handle *rec,
const char *key,
int type,
bool partial,
size_t *match_count)
{
struct saved_data *data = (struct saved_data *)rec->data;
struct spec *spec_arr = data->spec_arr;
int i, rc, file_stem;
mode_t mode = (mode_t)type;
char *clean_key = NULL;
const char *prev_slash, *next_slash;
unsigned int sofar = 0;
char *sub = NULL;
const struct spec **result = NULL;
if (match_count) {
*match_count = 0;
result = calloc(data->nspec, sizeof(struct spec*));
} else {
result = calloc(1, sizeof(struct spec*));
}
if (!result) {
selinux_log(SELINUX_ERROR, "%s: Out of memory\n", __func__);
goto finish;
}
if (!data->nspec) {
errno = ENOENT;
goto finish;
}
/* Remove duplicate slashes */
if ((next_slash = strstr(key, "//"))) {
clean_key = (char *) malloc(strlen(key) + 1);
if (!clean_key)
goto finish;
prev_slash = key;
while (next_slash) {
memcpy(clean_key + sofar, prev_slash, next_slash - prev_slash);
sofar += next_slash - prev_slash;
prev_slash = next_slash + 1;
next_slash = strstr(prev_slash, "//");
}
strcpy(clean_key + sofar, prev_slash);
key = clean_key;
}
sub = selabel_sub_key(data, key);
if (sub)
key = sub;
file_stem = find_stem_from_file(data, key);
mode &= S_IFMT;
/*
* Check for matching specifications in reverse order, so that
* the last matching specification is used.
*/
for (i = data->nspec - 1; i >= 0; i--) {
struct spec *spec = &spec_arr[i];
/* if the spec in question matches no stem or has the same
* stem as the file AND if the spec in question has no mode
* specified or if the mode matches the file mode then we do
* a regex check */
bool stem_matches = spec->stem_id == -1 || spec->stem_id == file_stem;
// Don't check the stem if we want to find partial matches.
// Otherwise the case "/abc/efg/(/.*)?" will be considered
//a miss for "/abc".
if ((partial || stem_matches) &&
(!mode || !spec->mode || mode == spec->mode)) {
if (compile_regex(spec, NULL) < 0)
goto finish;
rc = regex_match(spec->regex, key, partial);
if (rc == REGEX_MATCH || (partial && rc == REGEX_MATCH_PARTIAL)) {
if (rc == REGEX_MATCH) {
spec->matches++;
}
if (strcmp(spec_arr[i].lr.ctx_raw, "<<none>>") == 0) {
errno = ENOENT;
goto finish;
}
if (match_count) {
result[*match_count] = spec;
*match_count += 1;
// Continue to find all the matches.
continue;
}
result[0] = spec;
break;
}
if (rc == REGEX_NO_MATCH)
continue;
errno = ENOENT;
/* else it's an error */
goto finish;
}
}
finish:
free(clean_key);
free(sub);
if (result && !result[0]) {
free(result);
result = NULL;
}
return result;
}
static struct spec *lookup_common(struct selabel_handle *rec,
const char *key,
int type,
bool partial) {
const struct spec **matches = lookup_all(rec, key, type, partial, NULL);
if (!matches) {
return NULL;
}
struct spec *result = (struct spec*)matches[0];
free(matches);
return result;
}
static bool hash_all_partial_matches(struct selabel_handle *rec, const char *key, uint8_t *digest)
{
assert(digest);
size_t total_matches;
const struct spec **matches = lookup_all(rec, key, 0, true, &total_matches);
if (!matches) {
return false;
}
Sha1Context context;
Sha1Initialise(&context);
size_t i;
for (i = 0; i < total_matches; i++) {
char* regex_str = matches[i]->regex_str;
uint32_t mode = matches[i]->mode;
char* ctx_raw = matches[i]->lr.ctx_raw;
Sha1Update(&context, regex_str, strlen(regex_str) + 1);
Sha1Update(&context, &mode, sizeof(uint32_t));
Sha1Update(&context, ctx_raw, strlen(ctx_raw) + 1);
}
SHA1_HASH sha1_hash;
Sha1Finalise(&context, &sha1_hash);
memcpy(digest, sha1_hash.bytes, SHA1_HASH_SIZE);
free(matches);
return true;
}
static struct selabel_lookup_rec *lookup(struct selabel_handle *rec,
const char *key, int type)
{
struct spec *spec;
spec = lookup_common(rec, key, type, false);
if (spec)
return &spec->lr;
return NULL;
}
static bool partial_match(struct selabel_handle *rec, const char *key)
{
return lookup_common(rec, key, 0, true) ? true : false;
}
static struct selabel_lookup_rec *lookup_best_match(struct selabel_handle *rec,
const char *key,
const char **aliases,
int type)
{
size_t n, i;
int best = -1;
struct spec **specs;
size_t prefix_len = 0;
struct selabel_lookup_rec *lr = NULL;
if (!aliases || !aliases[0])
return lookup(rec, key, type);
for (n = 0; aliases[n]; n++)
;
specs = calloc(n+1, sizeof(struct spec *));
if (!specs)
return NULL;
specs[0] = lookup_common(rec, key, type, false);
if (specs[0]) {
if (!specs[0]->hasMetaChars) {
/* exact match on key */
lr = &specs[0]->lr;
goto out;
}
best = 0;
prefix_len = specs[0]->prefix_len;
}
for (i = 1; i <= n; i++) {
specs[i] = lookup_common(rec, aliases[i-1], type, false);
if (specs[i]) {
if (!specs[i]->hasMetaChars) {
/* exact match on alias */
lr = &specs[i]->lr;
goto out;
}
if (specs[i]->prefix_len > prefix_len) {
best = i;
prefix_len = specs[i]->prefix_len;
}
}
}
if (best >= 0) {
/* longest fixed prefix match on key or alias */
lr = &specs[best]->lr;
} else {
errno = ENOENT;
}
out:
free(specs);
return lr;
}
static enum selabel_cmp_result incomp(struct spec *spec1, struct spec *spec2, const char *reason, int i, int j)
{
selinux_log(SELINUX_INFO,
"selabel_cmp: mismatched %s on entry %d: (%s, %x, %s) vs entry %d: (%s, %x, %s)\n",
reason,
i, spec1->regex_str, spec1->mode, spec1->lr.ctx_raw,
j, spec2->regex_str, spec2->mode, spec2->lr.ctx_raw);
return SELABEL_INCOMPARABLE;
}
static enum selabel_cmp_result cmp(struct selabel_handle *h1,
struct selabel_handle *h2)
{
struct saved_data *data1 = (struct saved_data *)h1->data;
struct saved_data *data2 = (struct saved_data *)h2->data;
unsigned int i, nspec1 = data1->nspec, j, nspec2 = data2->nspec;
struct spec *spec_arr1 = data1->spec_arr, *spec_arr2 = data2->spec_arr;
struct stem *stem_arr1 = data1->stem_arr, *stem_arr2 = data2->stem_arr;
bool skipped1 = false, skipped2 = false;
i = 0;
j = 0;
while (i < nspec1 && j < nspec2) {
struct spec *spec1 = &spec_arr1[i];
struct spec *spec2 = &spec_arr2[j];
/*
* Because sort_specs() moves exact pathnames to the
* end, we might need to skip over additional regex
* entries that only exist in one of the configurations.
*/
if (!spec1->hasMetaChars && spec2->hasMetaChars) {
j++;
skipped2 = true;
continue;
}
if (spec1->hasMetaChars && !spec2->hasMetaChars) {
i++;
skipped1 = true;
continue;
}
if (spec1->regex && spec2->regex) {
if (regex_cmp(spec1->regex, spec2->regex) == SELABEL_INCOMPARABLE){
return incomp(spec1, spec2, "regex", i, j);
}
} else {
if (strcmp(spec1->regex_str, spec2->regex_str))
return incomp(spec1, spec2, "regex_str", i, j);
}
if (spec1->mode != spec2->mode)
return incomp(spec1, spec2, "mode", i, j);
if (spec1->stem_id == -1 && spec2->stem_id != -1)
return incomp(spec1, spec2, "stem_id", i, j);
if (spec2->stem_id == -1 && spec1->stem_id != -1)
return incomp(spec1, spec2, "stem_id", i, j);
if (spec1->stem_id != -1 && spec2->stem_id != -1) {
struct stem *stem1 = &stem_arr1[spec1->stem_id];
struct stem *stem2 = &stem_arr2[spec2->stem_id];
if (stem1->len != stem2->len ||
strncmp(stem1->buf, stem2->buf, stem1->len))
return incomp(spec1, spec2, "stem", i, j);
}
if (strcmp(spec1->lr.ctx_raw, spec2->lr.ctx_raw))
return incomp(spec1, spec2, "ctx_raw", i, j);
i++;
j++;
}
if ((skipped1 || i < nspec1) && !skipped2)
return SELABEL_SUPERSET;
if ((skipped2 || j < nspec2) && !skipped1)
return SELABEL_SUBSET;
if (skipped1 && skipped2)
return SELABEL_INCOMPARABLE;
return SELABEL_EQUAL;
}
static void stats(struct selabel_handle *rec)
{
struct saved_data *data = (struct saved_data *)rec->data;
unsigned int i, nspec = data->nspec;
struct spec *spec_arr = data->spec_arr;
for (i = 0; i < nspec; i++) {
if (spec_arr[i].matches == 0) {
if (spec_arr[i].type_str) {
COMPAT_LOG(SELINUX_WARNING,
"Warning! No matches for (%s, %s, %s)\n",
spec_arr[i].regex_str,
spec_arr[i].type_str,
spec_arr[i].lr.ctx_raw);
} else {
COMPAT_LOG(SELINUX_WARNING,
"Warning! No matches for (%s, %s)\n",
spec_arr[i].regex_str,
spec_arr[i].lr.ctx_raw);
}
}
}
}
int selabel_file_init(struct selabel_handle *rec,
const struct selinux_opt *opts,
unsigned nopts)
{
struct saved_data *data;
data = (struct saved_data *)malloc(sizeof(*data));
if (!data)
return -1;
memset(data, 0, sizeof(*data));
rec->data = data;
rec->func_close = &closef;
rec->func_stats = &stats;
rec->func_lookup = &lookup;
rec->func_partial_match = &partial_match;
rec->func_hash_all_partial_matches = &hash_all_partial_matches;
rec->func_lookup_best_match = &lookup_best_match;
rec->func_cmp = &cmp;
return init(rec, opts, nopts);
}