int main(int argc, char **argv)
{
char **buf, **ptr;
int ret;
if (argc != 3) {
fprintf(stderr, "usage: %s context user\n", argv[0]);
exit(1);
}
ret = security_compute_user(argv[1], argv[2], &buf);
if (ret < 0) {
fprintf(stderr, "%s: security_compute_user(%s,%s) failed\n", argv[0], argv[1], argv[2]);
exit(2);
}
if (!buf[0]) {
printf("none\n");
exit(0);
}
for (ptr = buf; *ptr; ptr++) {
printf("%s\n", *ptr);
}
freeconary(buf);
exit(0);
}
int get_ordered_context_list(const char *user,
security_context_t fromcon,
security_context_t ** list)
{
security_context_t *reachable = NULL;
unsigned int *ordering = NULL;
struct context_order *co = NULL;
char **ptr;
int rc = 0;
unsigned int nreach = 0, nordered = 0, freefrom = 0, i;
FILE *fp;
char *fname = NULL;
size_t fname_len;
const char *user_contexts_path = selinux_user_contexts_path();
if (!fromcon) {
/* Get the current context and use it for the starting context */
rc = getcon(&fromcon);
if (rc < 0)
return rc;
freefrom = 1;
}
/* Determine the set of reachable contexts for the user. */
rc = security_compute_user(fromcon, user, &reachable);
if (rc < 0) {
/* Retry with the default SELinux user identity. */
user = SELINUX_DEFAULTUSER;
rc = security_compute_user(fromcon, user, &reachable);
if (rc < 0)
goto failsafe;
}
nreach = 0;
for (ptr = reachable; *ptr; ptr++)
nreach++;
if (!nreach)
goto failsafe;
/* Initialize ordering array. */
ordering = malloc(nreach * sizeof(unsigned int));
if (!ordering)
goto oom_order;
for (i = 0; i < nreach; i++)
ordering[i] = nreach;
/* Determine the ordering to apply from the optional per-user config
and from the global config. */
fname_len = strlen(user_contexts_path) + strlen(user) + 2;
fname = malloc(fname_len);
if (!fname)
goto oom_order;
snprintf(fname, fname_len, "%s%s", user_contexts_path, user);
fp = fopen(fname, "r");
if (fp) {
__fsetlocking(fp, FSETLOCKING_BYCALLER);
rc = get_context_order(fp, fromcon, reachable, nreach, ordering,
&nordered);
fclose(fp);
if (rc < 0 && errno != ENOENT) {
fprintf(stderr,
"%s: error in processing configuration file %s\n",
__FUNCTION__, fname);
/* Fall through, try global config */
}
}
free(fname);
fp = fopen(selinux_default_context_path(), "r");
if (fp) {
__fsetlocking(fp, FSETLOCKING_BYCALLER);
rc = get_context_order(fp, fromcon, reachable, nreach, ordering,
&nordered);
fclose(fp);
if (rc < 0 && errno != ENOENT) {
fprintf(stderr,
"%s: error in processing configuration file %s\n",
__FUNCTION__, selinux_default_context_path());
/* Fall through */
}
}
/* Apply the ordering. */
if (nordered) {
co = malloc(nreach * sizeof(struct context_order));
if (!co)
goto oom_order;
for (i = 0; i < nreach; i++) {
co[i].con = reachable[i];
co[i].order = ordering[i];
}
qsort(co, nreach, sizeof(struct context_order), order_compare);
for (i = 0; i < nreach; i++)
reachable[i] = co[i].con;
free(co);
}
/* Return the ordered list.
If we successfully ordered it, then only report the ordered entries
to the caller. Otherwise, fall back to the entire reachable list. */
if (nordered && nordered < nreach) {
for (i = nordered; i < nreach; i++)
free(reachable[i]);
reachable[nordered] = NULL;
rc = nordered;
} else {
rc = nreach;
}
out:
*list = reachable;
free(ordering);
if (freefrom)
freecon(fromcon);
return rc;
failsafe:
/* Unable to determine a reachable context list, try to fall back to
the "failsafe" context to at least permit root login
for emergency recovery if possible. */
freeconary(reachable);
reachable = malloc(2 * sizeof(security_context_t));
if (!reachable) {
rc = -1;
goto out;
}
reachable[0] = reachable[1] = 0;
rc = get_failsafe_context(user, &reachable[0]);
if (rc < 0) {
freeconary(reachable);
reachable = NULL;
goto out;
}
rc = 1; /* one context in the list */
goto out;
oom_order:
/* Unable to order context list due to OOM condition.
Fall back to unordered reachable context list. */
fprintf(stderr, "%s: out of memory, unable to order list\n",
__FUNCTION__);
rc = nreach;
goto out;
}