| /* |
| * String representation support for classes and permissions. |
| */ |
| #include <sys/stat.h> |
| #include <dirent.h> |
| #include <fcntl.h> |
| #include <limits.h> |
| #include <unistd.h> |
| #include <errno.h> |
| #include <stddef.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <stdint.h> |
| #include <ctype.h> |
| #include "selinux_internal.h" |
| #include "policy.h" |
| #include "mapping.h" |
| |
| #define MAXVECTORS 8*sizeof(access_vector_t) |
| |
| struct discover_class_node { |
| char *name; |
| security_class_t value; |
| char **perms; |
| |
| struct discover_class_node *next; |
| }; |
| |
| static struct discover_class_node *discover_class_cache = NULL; |
| |
| static struct discover_class_node * get_class_cache_entry_name(const char *s) |
| { |
| struct discover_class_node *node = discover_class_cache; |
| |
| for (; node != NULL && strcmp(s,node->name) != 0; node = node->next); |
| |
| return node; |
| } |
| |
| static struct discover_class_node * get_class_cache_entry_value(security_class_t c) |
| { |
| struct discover_class_node *node = discover_class_cache; |
| |
| for (; node != NULL && c != node->value; node = node->next); |
| |
| return node; |
| } |
| |
| static struct discover_class_node * discover_class(const char *s) |
| { |
| int fd, ret; |
| char path[PATH_MAX]; |
| char buf[20]; |
| DIR *dir; |
| struct dirent *dentry; |
| size_t i; |
| |
| struct discover_class_node *node; |
| |
| if (!selinux_mnt) { |
| errno = ENOENT; |
| return NULL; |
| } |
| |
| /* allocate a node */ |
| node = malloc(sizeof(struct discover_class_node)); |
| if (node == NULL) |
| return NULL; |
| |
| /* allocate array for perms */ |
| node->perms = calloc(MAXVECTORS,sizeof(char*)); |
| if (node->perms == NULL) |
| goto err1; |
| |
| /* load up the name */ |
| node->name = strdup(s); |
| if (node->name == NULL) |
| goto err2; |
| |
| /* load up class index */ |
| snprintf(path, sizeof path, "%s/class/%s/index", selinux_mnt,s); |
| fd = open(path, O_RDONLY); |
| if (fd < 0) |
| goto err3; |
| |
| memset(buf, 0, sizeof(buf)); |
| ret = read(fd, buf, sizeof(buf) - 1); |
| close(fd); |
| if (ret < 0) |
| goto err3; |
| |
| if (sscanf(buf, "%hu", &node->value) != 1) |
| goto err3; |
| |
| /* load up permission indicies */ |
| snprintf(path, sizeof path, "%s/class/%s/perms",selinux_mnt,s); |
| dir = opendir(path); |
| if (dir == NULL) |
| goto err3; |
| |
| dentry = readdir(dir); |
| while (dentry != NULL) { |
| unsigned int value; |
| struct stat m; |
| |
| snprintf(path, sizeof path, "%s/class/%s/perms/%s", selinux_mnt,s,dentry->d_name); |
| fd = open(path, O_RDONLY | O_CLOEXEC); |
| if (fd < 0) |
| goto err4; |
| |
| if (fstat(fd, &m) < 0) { |
| close(fd); |
| goto err4; |
| } |
| |
| if (m.st_mode & S_IFDIR) { |
| close(fd); |
| dentry = readdir(dir); |
| continue; |
| } |
| |
| memset(buf, 0, sizeof(buf)); |
| ret = read(fd, buf, sizeof(buf) - 1); |
| close(fd); |
| if (ret < 0) |
| goto err4; |
| |
| if (sscanf(buf, "%u", &value) != 1) |
| goto err4; |
| |
| if (value == 0 || value > MAXVECTORS) |
| goto err4; |
| |
| node->perms[value-1] = strdup(dentry->d_name); |
| if (node->perms[value-1] == NULL) |
| goto err4; |
| |
| dentry = readdir(dir); |
| } |
| closedir(dir); |
| |
| node->next = discover_class_cache; |
| discover_class_cache = node; |
| |
| return node; |
| |
| err4: |
| closedir(dir); |
| for (i=0; i<MAXVECTORS; i++) |
| free(node->perms[i]); |
| err3: |
| free(node->name); |
| err2: |
| free(node->perms); |
| err1: |
| free(node); |
| return NULL; |
| } |
| |
| security_class_t string_to_security_class(const char *s) |
| { |
| struct discover_class_node *node; |
| |
| node = get_class_cache_entry_name(s); |
| if (node == NULL) { |
| node = discover_class(s); |
| |
| if (node == NULL) { |
| errno = EINVAL; |
| return 0; |
| } |
| } |
| |
| return map_class(node->value); |
| } |
| |
| access_vector_t string_to_av_perm(security_class_t tclass, const char *s) |
| { |
| struct discover_class_node *node; |
| security_class_t kclass = unmap_class(tclass); |
| |
| node = get_class_cache_entry_value(kclass); |
| if (node != NULL) { |
| size_t i; |
| for (i=0; i<MAXVECTORS && node->perms[i] != NULL; i++) |
| if (strcmp(node->perms[i],s) == 0) |
| return map_perm(tclass, 1<<i); |
| } |
| |
| errno = EINVAL; |
| return 0; |
| } |
| |
| const char *security_class_to_string(security_class_t tclass) |
| { |
| struct discover_class_node *node; |
| |
| tclass = unmap_class(tclass); |
| |
| node = get_class_cache_entry_value(tclass); |
| if (node) |
| return node->name; |
| return NULL; |
| } |
| |
| const char *security_av_perm_to_string(security_class_t tclass, |
| access_vector_t av) |
| { |
| struct discover_class_node *node; |
| size_t i; |
| |
| av = unmap_perm(tclass, av); |
| tclass = unmap_class(tclass); |
| |
| node = get_class_cache_entry_value(tclass); |
| if (av && node) |
| for (i = 0; i<MAXVECTORS; i++) |
| if ((1<<i) & av) |
| return node->perms[i]; |
| |
| return NULL; |
| } |
| |
| int security_av_string(security_class_t tclass, access_vector_t av, char **res) |
| { |
| unsigned int i = 0; |
| size_t len = 5; |
| access_vector_t tmp = av; |
| int rc = 0; |
| const char *str; |
| char *ptr; |
| |
| /* first pass computes the required length */ |
| while (tmp) { |
| if (tmp & 1) { |
| str = security_av_perm_to_string(tclass, av & (1<<i)); |
| if (str) |
| len += strlen(str) + 1; |
| else { |
| rc = -1; |
| errno = EINVAL; |
| goto out; |
| } |
| } |
| tmp >>= 1; |
| i++; |
| } |
| |
| *res = malloc(len); |
| if (!*res) { |
| rc = -1; |
| goto out; |
| } |
| |
| /* second pass constructs the string */ |
| i = 0; |
| tmp = av; |
| ptr = *res; |
| |
| if (!av) { |
| sprintf(ptr, "null"); |
| goto out; |
| } |
| |
| ptr += sprintf(ptr, "{ "); |
| while (tmp) { |
| if (tmp & 1) |
| ptr += sprintf(ptr, "%s ", security_av_perm_to_string( |
| tclass, av & (1<<i))); |
| tmp >>= 1; |
| i++; |
| } |
| sprintf(ptr, "}"); |
| out: |
| return rc; |
| } |