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 10 int 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 33 int 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
