blob: d40b6b082a3cdc75107a9e506dea5ae7bbf051d7 [file] [log] [blame]
#include <stdio.h>
#include <stdarg.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <stdint.h>
#include <search.h>
#include <stdbool.h>
#include <sepol/sepol.h>
#include <sepol/policydb/policydb.h>
#define TABLE_SIZE 1024
#define KVP_NUM_OF_RULES (sizeof(rules) / sizeof(key_map))
#define log_set_verbose() do { logging_verbose = 1; log_info("Enabling verbose\n"); } while(0)
#define log_error(fmt, ...) log_msg(stderr, "Error: ", fmt, ##__VA_ARGS__)
#define log_warn(fmt, ...) log_msg(stderr, "Warning: ", fmt, ##__VA_ARGS__)
#define log_info(fmt, ...) if (logging_verbose ) { log_msg(stdout, "Info: ", fmt, ##__VA_ARGS__); }
typedef struct line_order_list line_order_list;
typedef struct hash_entry hash_entry;
typedef enum key_dir key_dir;
typedef enum data_type data_type;
typedef enum rule_map_switch rule_map_switch;
typedef enum map_match map_match;
typedef struct key_map key_map;
typedef struct kvp kvp;
typedef struct rule_map rule_map;
typedef struct policy_info policy_info;
enum map_match {
map_no_matches,
map_input_matched,
map_matched
};
const char *map_match_str[] = {
"do not match",
"match on all inputs",
"match on everything"
};
/**
* Whether or not the "key" from a key vaue pair is considered an
* input or an output.
*/
enum key_dir {
dir_in, dir_out
};
/**
* Used as options to rule_map_free()
*
* This is needed to get around the fact that GNU C's hash_map doesn't copy the key, so
* we cannot free a key when overrding rule_map's in the table.
*/
enum rule_map_switch {
rule_map_preserve_key, /** Used to preserve the key in the rule_map, ie don't free it*/
rule_map_destroy_key /** Used when you need a full free of the rule_map structure*/
};
/**
* The expected "type" of data the value in the key
* value pair should be.
*/
enum data_type {
dt_bool, dt_string
};
/**
* This list is used to store a double pointer to each
* hash table / line rule combination. This way a replacement
* in the hash table automatically updates the list. The list
* is also used to keep "first encountered" ordering amongst
* the encountered key value pairs in the rules file.
*/
struct line_order_list {
hash_entry *e;
line_order_list *next;
};
/**
* The workhorse of the logic. This struct maps key value pairs to
* an associated set of meta data maintained in rule_map_new()
*/
struct key_map {
char *name;
key_dir dir;
data_type type;
char *data;
};
/**
* Key value pair struct, this represents the raw kvp values coming
* from the rules files.
*/
struct kvp {
char *key;
char *value;
};
/**
* Rules are made up of meta data and an associated set of kvp stored in a
* key_map array.
*/
struct rule_map {
char *key; /** key value before hashing */
size_t length; /** length of the key map */
int lineno; /** Line number rule was encounter on */
key_map m[]; /** key value mapping */
};
struct hash_entry {
rule_map *r; /** The rule map to store at that location */
};
/**
* Data associated for a policy file
*/
struct policy_info {
char *policy_file_name; /** policy file path name */
FILE *policy_file; /** file handle to the policy file */
sepol_policydb_t *db;
sepol_policy_file_t *pf;
sepol_handle_t *handle;
sepol_context_t *con;
};
/** Set to !0 to enable verbose logging */
static int logging_verbose = 0;
/** file handle to the output file */
static FILE *output_file = NULL;
/** file handle to the input file */
static FILE *input_file = NULL;
/** output file path name */
static char *out_file_name = NULL;
/** input file path name */
static char *in_file_name = NULL;
static policy_info pol = {
.policy_file_name = NULL,
.policy_file = NULL,
.db = NULL,
.pf = NULL,
.handle = NULL,
.con = NULL
};
/**
* The heart of the mapping process, this must be updated if a new key value pair is added
* to a rule.
*/
key_map rules[] = {
/*Inputs*/
{ .name = "isSystemServer", .type = dt_bool, .dir = dir_in, .data = NULL },
{ .name = "isOwner", .type = dt_bool, .dir = dir_in, .data = NULL },
{ .name = "user", .type = dt_string, .dir = dir_in, .data = NULL },
{ .name = "seinfo", .type = dt_string, .dir = dir_in, .data = NULL },
{ .name = "name", .type = dt_string, .dir = dir_in, .data = NULL },
{ .name = "path", .type = dt_string, .dir = dir_in, .data = NULL },
/*Outputs*/
{ .name = "domain", .type = dt_string, .dir = dir_out, .data = NULL },
{ .name = "type", .type = dt_string, .dir = dir_out, .data = NULL },
{ .name = "levelFromUid", .type = dt_bool, .dir = dir_out, .data = NULL },
{ .name = "levelFrom", .type = dt_string, .dir = dir_out, .data = NULL },
{ .name = "level", .type = dt_string, .dir = dir_out, .data = NULL },
};
/**
* Head pointer to a linked list of
* rule map table entries, used for
* preserving the order of entries
* based on "first encounter"
*/
static line_order_list *list_head = NULL;
/**
* Pointer to the tail of the list for
* quick appends to the end of the list
*/
static line_order_list *list_tail = NULL;
/**
* Send a logging message to a file
* @param out
* Output file to send message too
* @param prefix
* A special prefix to write to the file, such as "Error:"
* @param fmt
* The printf style formatter to use, such as "%d"
*/
static void __attribute__ ((format(printf, 3, 4)))
log_msg(FILE *out, const char *prefix, const char *fmt, ...) {
fprintf(out, "%s", prefix);
va_list args;
va_start(args, fmt);
vfprintf(out, fmt, args);
va_end(args);
}
/**
* Checks for a type in the policy.
* @param db
* The policy db to search
* @param type
* The type to search for
* @return
* 1 if the type is found, 0 otherwise.
* @warning
* This function always returns 1 if libsepol is not linked
* statically to this executable and LINK_SEPOL_STATIC is not
* defined.
*/
int check_type(sepol_policydb_t *db, char *type) {
int rc = 1;
#if defined(LINK_SEPOL_STATIC)
policydb_t *d = (policydb_t *)db;
hashtab_datum_t dat;
dat = hashtab_search(d->p_types.table, type);
rc = (dat == NULL) ? 0 : 1;
#endif
return rc;
}
/**
* Validates a key_map against a set of enforcement rules, this
* function exits the application on a type that cannot be properly
* checked
*
* @param m
* The key map to check
* @param lineno
* The line number in the source file for the corresponding key map
* @return
* 1 if valid, 0 if invalid
*/
static int key_map_validate(key_map *m, int lineno) {
int rc = 1;
int ret = 1;
char *key = m->name;
char *value = m->data;
data_type type = m->type;
log_info("Validating %s=%s\n", key, value);
/* Booleans can always be checked for sanity */
if (type == dt_bool && (!strcmp("true", value) || !strcmp("false", value))) {
goto out;
}
else if (type == dt_bool) {
log_error("Expected boolean value got: %s=%s on line: %d in file: %s\n",
key, value, lineno, out_file_name);
rc = 0;
goto out;
}
if (!strcasecmp(key, "levelFrom") &&
(strcasecmp(value, "none") && strcasecmp(value, "all") &&
strcasecmp(value, "app") && strcasecmp(value, "user"))) {
log_error("Unknown levelFrom=%s on line: %d in file: %s\n",
value, lineno, out_file_name);
rc = 0;
goto out;
}
/*
* If there is no policy file present,
* then it is not going to enforce the types against the policy so just return.
* User and name cannot really be checked.
*/
if (!pol.policy_file) {
goto out;
}
else if (!strcasecmp(key, "type") || !strcasecmp(key, "domain")) {
if(!check_type(pol.db, value)) {
log_error("Could not find selinux type \"%s\" on line: %d in file: %s\n", value,
lineno, out_file_name);
rc = 0;
}
goto out;
}
else if (!strcasecmp(key, "level")) {
ret = sepol_mls_check(pol.handle, pol.db, value);
if (ret < 0) {
log_error("Could not find selinux level \"%s\", on line: %d in file: %s\n", value,
lineno, out_file_name);
rc = 0;
goto out;
}
}
out:
log_info("Key map validate returning: %d\n", rc);
return rc;
}
/**
* Prints a rule map back to a file
* @param fp
* The file handle to print too
* @param r
* The rule map to print
*/
static void rule_map_print(FILE *fp, rule_map *r) {
size_t i;
key_map *m;
for (i = 0; i < r->length; i++) {
m = &(r->m[i]);
if (i < r->length - 1)
fprintf(fp, "%s=%s ", m->name, m->data);
else
fprintf(fp, "%s=%s", m->name, m->data);
}
}
/**
* Compare two rule maps for equality
* @param rmA
* a rule map to check
* @param rmB
* a rule map to check
* @return
* a map_match enum indicating the result
*/
static map_match rule_map_cmp(rule_map *rmA, rule_map *rmB) {
size_t i;
size_t j;
int inputs_found = 0;
int num_of_matched_inputs = 0;
int input_mode = 0;
size_t matches = 0;
key_map *mA;
key_map *mB;
for (i = 0; i < rmA->length; i++) {
mA = &(rmA->m[i]);
for (j = 0; j < rmB->length; j++) {
mB = &(rmB->m[j]);
input_mode = 0;
if (mA->type != mB->type)
continue;
if (strcmp(mA->name, mB->name))
continue;
if (strcmp(mA->data, mB->data))
continue;
if (mB->dir != mA->dir)
continue;
else if (mB->dir == dir_in) {
input_mode = 1;
inputs_found++;
}
if (input_mode) {
log_info("Matched input lines: name=%s data=%s\n", mA->name, mA->data);
num_of_matched_inputs++;
}
/* Match found, move on */
log_info("Matched lines: name=%s data=%s", mA->name, mA->data);
matches++;
break;
}
}
/* If they all matched*/
if (matches == rmA->length) {
log_info("Rule map cmp MATCH\n");
return map_matched;
}
/* They didn't all match but the input's did */
else if (num_of_matched_inputs == inputs_found) {
log_info("Rule map cmp INPUT MATCH\n");
return map_input_matched;
}
/* They didn't all match, and the inputs didn't match, ie it didn't
* match */
else {
log_info("Rule map cmp NO MATCH\n");
return map_no_matches;
}
}
/**
* Frees a rule map
* @param rm
* rule map to be freed.
*/
static void rule_map_free(rule_map *rm,
rule_map_switch s __attribute__((unused)) /* only glibc builds, ignored otherwise */) {
size_t i;
size_t len = rm->length;
for (i = 0; i < len; i++) {
key_map *m = &(rm->m[i]);
free(m->data);
}
/* hdestroy() frees comparsion keys for non glibc */
#ifdef __GLIBC__
if(s == rule_map_destroy_key && rm->key)
free(rm->key);
#endif
free(rm);
}
static void free_kvp(kvp *k) {
free(k->key);
free(k->value);
}
/**
* Checks a rule_map for any variation of KVP's that shouldn't be allowed.
* Note that this function logs all errors.
*
* Current Checks:
* 1. That a specified name entry should have a specified seinfo entry as well.
* @param rm
* The rule map to check for validity.
* @return
* true if the rule is valid, false otherwise.
*/
static bool rule_map_validate(const rule_map *rm) {
size_t i;
bool found_name = false;
bool found_seinfo = false;
char *name = NULL;
const key_map *tmp;
for(i=0; i < rm->length; i++) {
tmp = &(rm->m[i]);
if(!strcmp(tmp->name, "name") && tmp->data) {
name = tmp->data;
found_name = true;
}
if(!strcmp(tmp->name, "seinfo") && tmp->data && strcmp(tmp->data, "default")) {
found_seinfo = true;
}
}
if(found_name && !found_seinfo) {
log_error("No specific seinfo value specified with name=\"%s\", on line: %d: insecure configuration!\n",
name, rm->lineno);
return false;
}
return true;
}
/**
* Given a set of key value pairs, this will construct a new rule map.
* On error this function calls exit.
* @param keys
* Keys from a rule line to map
* @param num_of_keys
* The length of the keys array
* @param lineno
* The line number the keys were extracted from
* @return
* A rule map pointer.
*/
static rule_map *rule_map_new(kvp keys[], size_t num_of_keys, int lineno) {
size_t i = 0, j = 0;
bool valid_rule;
rule_map *new_map = NULL;
kvp *k = NULL;
key_map *r = NULL, *x = NULL;
bool seen[KVP_NUM_OF_RULES];
for (i = 0; i < KVP_NUM_OF_RULES; i++)
seen[i] = false;
new_map = calloc(1, (num_of_keys * sizeof(key_map)) + sizeof(rule_map));
if (!new_map)
goto oom;
new_map->length = num_of_keys;
new_map->lineno = lineno;
/* For all the keys in a rule line*/
for (i = 0; i < num_of_keys; i++) {
k = &(keys[i]);
r = &(new_map->m[i]);
for (j = 0; j < KVP_NUM_OF_RULES; j++) {
x = &(rules[j]);
/* Only assign key name to map name */
if (strcasecmp(k->key, x->name)) {
if (i == KVP_NUM_OF_RULES) {
log_error("No match for key: %s\n", k->key);
goto err;
}
continue;
}
if (seen[j]) {
log_error("Duplicated key: %s\n", k->key);
goto err;
}
seen[j] = true;
memcpy(r, x, sizeof(key_map));
/* Assign rule map value to one from file */
r->data = strdup(k->value);
if (!r->data)
goto oom;
/* Enforce type check*/
log_info("Validating keys!\n");
if (!key_map_validate(r, lineno)) {
log_error("Could not validate\n");
goto err;
}
/* Only build key off of inputs*/
if (r->dir == dir_in) {
char *tmp;
int key_len = strlen(k->key);
int val_len = strlen(k->value);
int l = (new_map->key) ? strlen(new_map->key) : 0;
l = l + key_len + val_len;
l += 1;
tmp = realloc(new_map->key, l);
if (!tmp)
goto oom;
if (!new_map->key)
memset(tmp, 0, l);
new_map->key = tmp;
strncat(new_map->key, k->key, key_len);
strncat(new_map->key, k->value, val_len);
}
break;
}
free_kvp(k);
}
if (new_map->key == NULL) {
log_error("Strange, no keys found, input file corrupt perhaps?\n");
goto err;
}
valid_rule = rule_map_validate(new_map);
if(!valid_rule) {
/* Error message logged from rule_map_validate() */
goto err;
}
return new_map;
oom:
log_error("Out of memory!\n");
err:
if(new_map) {
rule_map_free(new_map, rule_map_destroy_key);
for (; i < num_of_keys; i++) {
k = &(keys[i]);
free_kvp(k);
}
}
return NULL;
}
/**
* Print the usage of the program
*/
static void usage() {
printf(
"checkseapp [options] <input file>\n"
"Processes an seapp_contexts file specified by argument <input file> (default stdin) "
"and allows later declarations to override previous ones on a match.\n"
"Options:\n"
"-h - print this help message\n"
"-v - enable verbose debugging informations\n"
"-p policy file - specify policy file for strict checking of output selectors against the policy\n"
"-o output file - specify output file, default is stdout\n");
}
static void init() {
/* If not set on stdin already */
if(!input_file) {
log_info("Opening input file: %s\n", in_file_name);
input_file = fopen(in_file_name, "r");
if (!input_file) {
log_error("Could not open file: %s error: %s\n", in_file_name, strerror(errno));
exit(EXIT_FAILURE);
}
}
/* If not set on std out already */
if(!output_file) {
output_file = fopen(out_file_name, "w+");
if (!output_file) {
log_error("Could not open file: %s error: %s\n", out_file_name, strerror(errno));
exit(EXIT_FAILURE);
}
}
if (pol.policy_file_name) {
log_info("Opening policy file: %s\n", pol.policy_file_name);
pol.policy_file = fopen(pol.policy_file_name, "rb");
if (!pol.policy_file) {
log_error("Could not open file: %s error: %s\n",
pol.policy_file_name, strerror(errno));
exit(EXIT_FAILURE);
}
pol.handle = sepol_handle_create();
if (!pol.handle) {
log_error("Could not create sepolicy handle: %s\n",
strerror(errno));
exit(EXIT_FAILURE);
}
if (sepol_policy_file_create(&pol.pf) < 0) {
log_error("Could not create sepolicy file: %s!\n",
strerror(errno));
exit(EXIT_FAILURE);
}
sepol_policy_file_set_fp(pol.pf, pol.policy_file);
sepol_policy_file_set_handle(pol.pf, pol.handle);
if (sepol_policydb_create(&pol.db) < 0) {
log_error("Could not create sepolicy db: %s!\n",
strerror(errno));
exit(EXIT_FAILURE);
}
if (sepol_policydb_read(pol.db, pol.pf) < 0) {
log_error("Could not lod policy file to db: %s!\n",
strerror(errno));
exit(EXIT_FAILURE);
}
}
log_info("Policy file set to: %s\n", (pol.policy_file_name == NULL) ? "None" : pol.policy_file_name);
log_info("Input file set to: %s\n", (in_file_name == NULL) ? "stdin" : in_file_name);
log_info("Output file set to: %s\n", (out_file_name == NULL) ? "stdout" : out_file_name);
#if !defined(LINK_SEPOL_STATIC)
log_warn("LINK_SEPOL_STATIC is not defined\n""Not checking types!");
#endif
}
/**
* Handle parsing and setting the global flags for the command line
* options. This function calls exit on failure.
* @param argc
* argument count
* @param argv
* argument list
*/
static void handle_options(int argc, char *argv[]) {
int c;
int num_of_args;
while ((c = getopt(argc, argv, "ho:p:sv")) != -1) {
switch (c) {
case 'h':
usage();
exit(EXIT_SUCCESS);
case 'o':
out_file_name = optarg;
break;
case 'p':
pol.policy_file_name = optarg;
break;
case 'v':
log_set_verbose();
break;
case '?':
if (optopt == 'o' || optopt == 'p')
log_error("Option -%c requires an argument.\n", optopt);
else if (isprint (optopt))
log_error("Unknown option `-%c'.\n", optopt);
else {
log_error(
"Unknown option character `\\x%x'.\n",
optopt);
}
default:
exit(EXIT_FAILURE);
}
}
num_of_args = argc - optind;
if (num_of_args > 1) {
log_error("Too many arguments, expected 0 or 1, argument, got %d\n", num_of_args);
usage();
exit(EXIT_FAILURE);
} else if (num_of_args == 1) {
in_file_name = argv[argc - 1];
} else {
input_file = stdin;
in_file_name = "stdin";
}
if (!out_file_name) {
output_file = stdout;
out_file_name = "stdout";
}
}
/**
* Adds a rule_map double pointer, ie the hash table pointer to the list.
* By using a double pointer, the hash table can have a line be overridden
* and the value is updated in the list. This function calls exit on failure.
* @param rm
* the rule_map to add.
*/
static void list_add(hash_entry *e) {
line_order_list *node = malloc(sizeof(line_order_list));
if (node == NULL)
goto oom;
node->next = NULL;
node->e = e;
if (list_head == NULL)
list_head = list_tail = node;
else {
list_tail->next = node;
list_tail = list_tail->next;
}
return;
oom:
log_error("Out of memory!\n");
exit(EXIT_FAILURE);
}
/**
* Free's the rule map list, which ultimatley contains
* all the malloc'd rule_maps.
*/
static void list_free() {
line_order_list *cursor, *tmp;
hash_entry *e;
cursor = list_head;
while (cursor) {
e = cursor->e;
rule_map_free(e->r, rule_map_destroy_key);
tmp = cursor;
cursor = cursor->next;
free(e);
free(tmp);
}
}
/**
* Adds a rule to the hash table and to the ordered list if needed.
* @param rm
* The rule map to add.
*/
static void rule_add(rule_map *rm) {
map_match cmp;
ENTRY e;
ENTRY *f;
hash_entry *entry;
hash_entry *tmp;
e.key = rm->key;
log_info("Searching for key: %s\n", e.key);
/* Check to see if it has already been added*/
f = hsearch(e, FIND);
/*
* Since your only hashing on a partial key, the inputs we need to handle
* when you want to override the outputs for a given input set, as well as
* checking for duplicate entries.
*/
if(f) {
log_info("Existing entry found!\n");
tmp = (hash_entry *)f->data;
cmp = rule_map_cmp(rm, tmp->r);
log_error("Duplicate line detected in file: %s\n"
"Lines %d and %d %s!\n",
in_file_name, tmp->r->lineno, rm->lineno,
map_match_str[cmp]);
rule_map_free(rm, rule_map_destroy_key);
goto err;
}
/* It wasn't found, just add the rule map to the table */
else {
entry = malloc(sizeof(hash_entry));
if (!entry)
goto oom;
entry->r = rm;
e.data = entry;
f = hsearch(e, ENTER);
if(f == NULL) {
goto oom;
}
/* new entries must be added to the ordered list */
entry->r = rm;
list_add(entry);
}
return;
oom:
if (e.key)
free(e.key);
if (entry)
free(entry);
if (rm)
free(rm);
log_error("Out of memory in function: %s\n", __FUNCTION__);
err:
exit(EXIT_FAILURE);
}
/**
* Parses the seapp_contexts file and adds them to the
* hash table and ordered list entries when it encounters them.
* Calls exit on failure.
*/
static void parse() {
char line_buf[BUFSIZ];
char *token;
unsigned lineno = 0;
char *p, *name = NULL, *value = NULL, *saveptr;
size_t len;
kvp keys[KVP_NUM_OF_RULES];
size_t token_cnt = 0;
while (fgets(line_buf, sizeof line_buf - 1, input_file)) {
lineno++;
log_info("Got line %d\n", lineno);
len = strlen(line_buf);
if (line_buf[len - 1] == '\n')
line_buf[len - 1] = '\0';
p = line_buf;
while (isspace(*p))
p++;
if (*p == '#' || *p == '\0')
continue;
token = strtok_r(p, " \t", &saveptr);
if (!token)
goto err;
token_cnt = 0;
memset(keys, 0, sizeof(kvp) * KVP_NUM_OF_RULES);
while (1) {
name = token;
value = strchr(name, '=');
if (!value)
goto err;
*value++ = 0;
keys[token_cnt].key = strdup(name);
if (!keys[token_cnt].key)
goto oom;
keys[token_cnt].value = strdup(value);
if (!keys[token_cnt].value)
goto oom;
token_cnt++;
token = strtok_r(NULL, " \t", &saveptr);
if (!token)
break;
} /*End token parsing */
rule_map *r = rule_map_new(keys, token_cnt, lineno);
if (!r)
goto err;
rule_add(r);
} /* End file parsing */
return;
err:
log_error("reading %s, line %u, name %s, value %s\n",
in_file_name, lineno, name, value);
exit(EXIT_FAILURE);
oom:
log_error("In function %s: Out of memory\n", __FUNCTION__);
exit(EXIT_FAILURE);
}
/**
* Should be called after parsing to cause the printing of the rule_maps
* stored in the ordered list, head first, which preserves the "first encountered"
* ordering.
*/
static void output() {
rule_map *r;
line_order_list *cursor;
cursor = list_head;
while (cursor) {
r = cursor->e->r;
rule_map_print(output_file, r);
cursor = cursor->next;
fprintf(output_file, "\n");
}
}
/**
* This function is registered to the at exit handler and should clean up
* the programs dynamic resources, such as memory and fd's.
*/
static void cleanup() {
/* Only close this when it was opened by me and not the crt */
if (out_file_name && output_file) {
log_info("Closing file: %s\n", out_file_name);
fclose(output_file);
}
/* Only close this when it was opened by me and not the crt */
if (in_file_name && input_file) {
log_info("Closing file: %s\n", in_file_name);
fclose(input_file);
}
if (pol.policy_file) {
log_info("Closing file: %s\n", pol.policy_file_name);
fclose(pol.policy_file);
if (pol.db)
sepol_policydb_free(pol.db);
if (pol.pf)
sepol_policy_file_free(pol.pf);
if (pol.handle)
sepol_handle_destroy(pol.handle);
}
log_info("Freeing list\n");
list_free();
hdestroy();
}
int main(int argc, char *argv[]) {
if (!hcreate(TABLE_SIZE)) {
log_error("Could not create hash table: %s\n", strerror(errno));
exit(EXIT_FAILURE);
}
atexit(cleanup);
handle_options(argc, argv);
init();
log_info("Starting to parse\n");
parse();
log_info("Parsing completed, generating output\n");
output();
log_info("Success, generated output\n");
exit(EXIT_SUCCESS);
}