policydb_convert.c revision 13cd4c8960688af11ad23b4c946149015c80d549 
1#include <stdlib.h>
2
3#include "private.h"
4#include "debug.h"
5
6#include <sepol/policydb/policydb.h>
7
8/* Construct a policydb from the supplied (data, len) pair */
9
10int policydb_from_image(sepol_handle_t * handle,
11			void *data, size_t len, policydb_t * policydb)
12{
13
14	policy_file_t pf;
15
16	policy_file_init(&pf);
17	pf.type = PF_USE_MEMORY;
18	pf.data = data;
19	pf.len = len;
20	pf.handle = handle;
21
22	if (policydb_read(policydb, &pf, 0)) {
23		ERR(handle, "policy image is invalid");
24		errno = EINVAL;
25		return STATUS_ERR;
26	}
27
28	return STATUS_SUCCESS;
29}
30
31/* Write a policydb to a memory region, and return the (data, len) pair. */
32
33int policydb_to_image(sepol_handle_t * handle,
34		      policydb_t * policydb, void **newdata, size_t * newlen)
35{
36
37	void *tmp_data = NULL;
38	size_t tmp_len;
39	policy_file_t pf;
40	struct policydb tmp_policydb;
41
42	/* Compute the length for the new policy image. */
43	policy_file_init(&pf);
44	pf.type = PF_LEN;
45	pf.handle = handle;
46	if (policydb_write(policydb, &pf)) {
47		ERR(handle, "could not compute policy length");
48		errno = EINVAL;
49		goto err;
50	}
51
52	/* Allocate the new policy image. */
53	pf.type = PF_USE_MEMORY;
54	pf.data = malloc(pf.len);
55	if (!pf.data) {
56		ERR(handle, "out of memory");
57		goto err;
58	}
59
60	/* Need to save len and data prior to modification by policydb_write. */
61	tmp_len = pf.len;
62	tmp_data = pf.data;
63
64	/* Write out the new policy image. */
65	if (policydb_write(policydb, &pf)) {
66		ERR(handle, "could not write policy");
67		errno = EINVAL;
68		goto err;
69	}
70
71	/* Verify the new policy image. */
72	pf.type = PF_USE_MEMORY;
73	pf.data = tmp_data;
74	pf.len = tmp_len;
75	if (policydb_init(&tmp_policydb)) {
76		ERR(handle, "Out of memory");
77		errno = ENOMEM;
78		goto err;
79	}
80	if (policydb_read(&tmp_policydb, &pf, 0)) {
81		ERR(handle, "new policy image is invalid");
82		errno = EINVAL;
83		goto err;
84	}
85	policydb_destroy(&tmp_policydb);
86
87	/* Update (newdata, newlen) */
88	*newdata = tmp_data;
89	*newlen = tmp_len;
90
91	/* Recover */
92	return STATUS_SUCCESS;
93
94      err:
95	ERR(handle, "could not create policy image");
96
97	/* Recover */
98	free(tmp_data);
99	return STATUS_ERR;
100}
101