1 #include <unistd.h> 2 #include <sys/types.h> 3 #include <fcntl.h> 4 #include <stdlib.h> 5 #include <stdio.h> 6 #include <errno.h> 7 #include <string.h> 8 #include <limits.h> 9 #include "selinux_internal.h" 10 #include "policy.h" 11 #include "mapping.h" 12 13 int security_compute_av(const security_context_t scon, 14 const security_context_t tcon, 15 security_class_t tclass, 16 access_vector_t requested, 17 struct av_decision *avd) 18 { 19 char path[PATH_MAX]; 20 char *buf; 21 size_t len; 22 int fd, ret; 23 24 if (!selinux_mnt) { 25 errno = ENOENT; 26 return -1; 27 } 28 29 snprintf(path, sizeof path, "%s/access", selinux_mnt); 30 fd = open(path, O_RDWR); 31 if (fd < 0) 32 return -1; 33 34 len = selinux_page_size; 35 buf = malloc(len); 36 if (!buf) { 37 ret = -1; 38 goto out; 39 } 40 41 snprintf(buf, len, "%s %s %hu %x", scon, tcon, 42 unmap_class(tclass), unmap_perm(tclass, requested)); 43 44 ret = write(fd, buf, strlen(buf)); 45 if (ret < 0) 46 goto out2; 47 48 memset(buf, 0, len); 49 ret = read(fd, buf, len - 1); 50 if (ret < 0) 51 goto out2; 52 53 ret = sscanf(buf, "%x %x %x %x %u %x", 54 &avd->allowed, &avd->decided, 55 &avd->auditallow, &avd->auditdeny, 56 &avd->seqno, &avd->flags); 57 if (ret < 5) { 58 ret = -1; 59 goto out2; 60 } else if (ret < 6) 61 avd->flags = 0; 62 63 map_decision(tclass, avd); 64 65 ret = 0; 66 out2: 67 free(buf); 68 out: 69 close(fd); 70 return ret; 71 } 72 73
