selinux/libselinux/src/compute_create.c
Stephen Smalley 9eb9c93275 Get rid of security_context_t and fix const declarations.
In attempting to enable building various part of Android with -Wall -Werror,
we found that the const security_context_t declarations in libselinux
are incorrect; const char * was intended, but const security_context_t
translates to char * const and triggers warnings on passing
const char * from the caller.   Easiest fix is to replace them all with
const char *.  And while we are at it, just get rid of all usage of
security_context_t itself as it adds no value - there is no true
encapsulation of the security context strings and callers already
directly use string functions on them.  typedef left to permit
building legacy users until such a time as all are updated.

This is a port of Change-Id I2f9df7bb9f575f76024c3e5f5b660345da2931a7
from Android, augmented to deal with all of the other code in upstream
libselinux and updating the man pages too.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Eric Paris <eparis@redhat.com>
2014-02-19 16:11:48 -05:00

159 lines
3.1 KiB
C

#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <limits.h>
#include <ctype.h>
#include "selinux_internal.h"
#include "policy.h"
#include "mapping.h"
static int object_name_encode(const char *objname, char *buffer, size_t buflen)
{
int code;
size_t offset = 0;
if (buflen - offset < 1)
return -1;
buffer[offset++] = ' ';
do {
code = *objname++;
if (isalnum(code) || code == '\0' || code == '-' ||
code == '.' || code == '_' || code == '~') {
if (buflen - offset < 1)
return -1;
buffer[offset++] = code;
} else if (code == ' ') {
if (buflen - offset < 1)
return -1;
buffer[offset++] = '+';
} else {
static const char *table = "0123456789ABCDEF";
int l = (code & 0x0f);
int h = (code & 0xf0) >> 4;
if (buflen - offset < 3)
return -1;
buffer[offset++] = '%';
buffer[offset++] = table[h];
buffer[offset++] = table[l];
}
} while (code != '\0');
return 0;
}
int security_compute_create_name_raw(const char * scon,
const char * tcon,
security_class_t tclass,
const char *objname,
char ** newcon)
{
char path[PATH_MAX];
char *buf;
size_t size;
int fd, ret, len;
if (!selinux_mnt) {
errno = ENOENT;
return -1;
}
snprintf(path, sizeof path, "%s/create", selinux_mnt);
fd = open(path, O_RDWR);
if (fd < 0)
return -1;
size = selinux_page_size;
buf = malloc(size);
if (!buf) {
ret = -1;
goto out;
}
len = snprintf(buf, size, "%s %s %hu",
scon, tcon, unmap_class(tclass));
if (objname &&
object_name_encode(objname, buf + len, size - len) < 0) {
errno = ENAMETOOLONG;
ret = -1;
goto out2;
}
ret = write(fd, buf, strlen(buf));
if (ret < 0)
goto out2;
memset(buf, 0, size);
ret = read(fd, buf, size - 1);
if (ret < 0)
goto out2;
*newcon = strdup(buf);
if (!(*newcon)) {
ret = -1;
goto out2;
}
ret = 0;
out2:
free(buf);
out:
close(fd);
return ret;
}
hidden_def(security_compute_create_name_raw)
int security_compute_create_raw(const char * scon,
const char * tcon,
security_class_t tclass,
char ** newcon)
{
return security_compute_create_name_raw(scon, tcon, tclass,
NULL, newcon);
}
hidden_def(security_compute_create_raw)
int security_compute_create_name(const char * scon,
const char * tcon,
security_class_t tclass,
const char *objname,
char ** newcon)
{
int ret;
char * rscon;
char * rtcon;
char * rnewcon;
if (selinux_trans_to_raw_context(scon, &rscon))
return -1;
if (selinux_trans_to_raw_context(tcon, &rtcon)) {
freecon(rscon);
return -1;
}
ret = security_compute_create_name_raw(rscon, rtcon, tclass,
objname, &rnewcon);
freecon(rscon);
freecon(rtcon);
if (!ret) {
ret = selinux_raw_to_trans_context(rnewcon, newcon);
freecon(rnewcon);
}
return ret;
}
hidden_def(security_compute_create_name)
int security_compute_create(const char * scon,
const char * tcon,
security_class_t tclass,
char ** newcon)
{
return security_compute_create_name(scon, tcon, tclass, NULL, newcon);
}
hidden_def(security_compute_create)