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#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sepol/policydb/services.h>
#include <sepol/sepol.h>
int main(int argc, char *argv[])
{
FILE *fp;
sepol_security_id_t ssid, tsid;
sepol_security_class_t tclass;
const char *permlist;
sepol_access_vector_t av;
struct sepol_av_decision avd;
unsigned int reason;
char *reason_buf;
int i;
if (argc != 6) {
printf("usage: %s policy source_context target_context class permission[,permission2[,...]]\n", argv[0]);
return 1;
}
fp = fopen(argv[1], "r");
if (!fp) {
fprintf(stderr, "Can't open policy %s: %s\n", argv[1], strerror(errno));
return 1;
}
if (sepol_set_policydb_from_file(fp) < 0) {
fprintf(stderr, "Error while processing policy %s: %s\n", argv[1], strerror(errno));
fclose(fp);
return 1;
}
fclose(fp);
if (sepol_context_to_sid(argv[2], strlen(argv[2]), &ssid) < 0) {
fprintf(stderr, "Invalid source context %s\n", argv[2]);
return 1;
}
if (sepol_context_to_sid(argv[3], strlen(argv[3]), &tsid) < 0) {
fprintf(stderr, "Invalid target context %s\n", argv[3]);
return 1;
}
if (sepol_string_to_security_class(argv[4], &tclass) < 0) {
fprintf(stderr, "Invalid security class %s\n", argv[4]);
return 1;
}
permlist = argv[5];
do {
char *tmp = NULL;
const char *perm;
const char *delim = strchr(permlist, ',');
if (delim) {
tmp = strndup(permlist, delim - permlist);
if (!tmp) {
fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
return 1;
}
}
perm = tmp ? tmp : permlist;
if (sepol_string_to_av_perm(tclass, perm, &av) < 0) {
fprintf(stderr, "Invalid permission %s for security class %s: %s\n", perm, argv[4], strerror(errno));
free(tmp);
return 1;
}
free(tmp);
permlist = strchr(permlist, ',');
} while (permlist++);
if (av == 0) {
fprintf(stderr, "Empty permission set computed from %s\n", argv[5]);
return 1;
}
if (sepol_compute_av_reason_buffer(ssid, tsid, tclass, av, &avd, &reason, &reason_buf, 0) < 0) {
fprintf(stderr, "Failed to compute av decision: %s\n", strerror(errno));
return 1;
}
if ((avd.allowed & av) == av) {
printf("requested permission %s allowed\n", argv[5]);
free(reason_buf);
return 0;
}
printf("requested permission %s denied by ", argv[5]);
i = 0;
if (reason & SEPOL_COMPUTEAV_TE) {
printf("te-rule");
i++;
}
if (reason & SEPOL_COMPUTEAV_CONS) {
if (i > 0)
printf(", ");
printf("constraint");
i++;
}
if (reason & SEPOL_COMPUTEAV_RBAC) {
if (i > 0)
printf(", ");
printf("role-transition");
i++;
}
if (reason & SEPOL_COMPUTEAV_BOUNDS) {
if (i > 0)
printf(", ");
printf("type-bound");
//i++;
}
if ((reason & SEPOL_COMPUTEAV_CONS) && reason_buf)
printf("; reason:\n%s", reason_buf);
free(reason_buf);
printf("\n");
return 7;
}
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