+#define POSIX_ACL_XATTR_VERSION 0x0002
+
+#define ACL_UNDEFINED_ID (-1)
+
+#define ACL_USER_OBJ (0x01)
+#define ACL_USER (0x02)
+#define ACL_GROUP_OBJ (0x04)
+#define ACL_GROUP (0x08)
+#define ACL_MASK (0x10)
+#define ACL_OTHER (0x20)
+
+typedef struct {
+ u_int16_t e_tag;
+ u_int16_t e_perm;
+ u_int32_t e_id;
+} posix_acl_xattr_entry;
+
+typedef struct {
+ u_int32_t a_version;
+ posix_acl_xattr_entry a_entries[0];
+} posix_acl_xattr_header;
+
+static inline size_t
+posix_acl_xattr_size(int count)
+{
+ return (sizeof(posix_acl_xattr_header) +
+ (count * sizeof(posix_acl_xattr_entry)));
+}
+
+struct posix_acl_entry {
+ short e_tag;
+ unsigned short e_perm;
+ unsigned int e_id;
+};
+
+struct posix_acl {
+ unsigned int a_count;
+ struct posix_acl_entry a_entries[0];
+};
+
+#define EXT3_ACL_VERSION 0x0001
+
+typedef struct {
+ u_int16_t e_tag;
+ u_int16_t e_perm;
+ u_int32_t e_id;
+} ext3_acl_entry;
+
+typedef struct {
+ u_int16_t e_tag;
+ u_int16_t e_perm;
+} ext3_acl_entry_short;
+
+typedef struct {
+ u_int32_t a_version;
+} ext3_acl_header;
+
+static inline int ext3_acl_count(size_t size)
+{
+ ssize_t s;
+ size -= sizeof(ext3_acl_header);
+ s = size - 4 * sizeof(ext3_acl_entry_short);
+ if (s < 0) {
+ if (size % sizeof(ext3_acl_entry_short))
+ return -1;
+ return size / sizeof(ext3_acl_entry_short);
+ } else {
+ if (s % sizeof(ext3_acl_entry))
+ return -1;
+ return s / sizeof(ext3_acl_entry) + 4;
+ }
+}
+
+int
+posix_acl_to_xattr(const struct posix_acl *acl, void *buffer, size_t size) {
+ posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer;
+ posix_acl_xattr_entry *ext_entry = ext_acl->a_entries;
+ int real_size, n;
+
+ real_size = posix_acl_xattr_size(acl->a_count);
+ if (!buffer)
+ return real_size;
+ if (real_size > size) {
+ fprintf(stderr, "ACL: not enough space to convert (%d %d)\n", real_size, size);
+ return -1;
+ }
+
+ ext_acl->a_version = POSIX_ACL_XATTR_VERSION;
+#if BYTE_ORDER == BIG_ENDIAN
+ swabst("1i", (u_char *)ext_acl);
+#endif
+
+ for (n=0; n < acl->a_count; n++, ext_entry++) {
+ ext_entry->e_tag = acl->a_entries[n].e_tag;
+ ext_entry->e_perm = acl->a_entries[n].e_perm;
+ ext_entry->e_id = acl->a_entries[n].e_id;
+#if BYTE_ORDER == BIG_ENDIAN
+ swabst("2s1i", (u_char *)ext_entry);
+#endif
+ }
+ return real_size;
+}
+
+static struct posix_acl *
+ext3_acl_from_disk(const void *value, size_t size)
+{
+ const char *end = (char *)value + size;
+ int n, count;
+ struct posix_acl *acl;
+
+ if (!value)
+ return NULL;
+ if (size < sizeof(ext3_acl_header)) {
+ fprintf(stderr, "ACL size too little\n");
+ return NULL;
+ }
+#if BYTE_ORDER == BIG_ENDIAN
+ swabst("1i", (u_char *)value);
+#endif
+ if (((ext3_acl_header *)value)->a_version != EXT3_ACL_VERSION) {
+ fprintf(stderr, "ACL version unknown\n");
+ return NULL;
+ }
+ value = (char *)value + sizeof(ext3_acl_header);
+ count = ext3_acl_count(size);
+ if (count < 0) {
+ fprintf(stderr, "ACL bad count\n");
+ return NULL;
+ }
+ if (count == 0)
+ return NULL;
+ acl = malloc(sizeof(struct posix_acl) + count * sizeof(struct posix_acl_entry));
+ if (!acl) {
+ fprintf(stderr, "ACL malloc failed\n");
+ return NULL;
+ }
+ acl->a_count = count;
+
+ for (n=0; n < count; n++) {
+ ext3_acl_entry *entry = (ext3_acl_entry *)value;
+#if BYTE_ORDER == BIG_ENDIAN
+ swabst("2s", (u_char *)entry);
+#endif
+ if ((char *)value + sizeof(ext3_acl_entry_short) > end)
+ goto fail;
+ acl->a_entries[n].e_tag = entry->e_tag;
+ acl->a_entries[n].e_perm = entry->e_perm;
+ switch(acl->a_entries[n].e_tag) {
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ value = (char *)value + sizeof(ext3_acl_entry_short);
+ acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
+ break;
+
+ case ACL_USER:
+ case ACL_GROUP:
+#if BYTE_ORDER == BIG_ENDIAN
+ swabst("4b1i", (u_char *)entry);
+#endif
+ value = (char *)value + sizeof(ext3_acl_entry);
+ if ((char *)value > end)
+ goto fail;
+ acl->a_entries[n].e_id = entry->e_id;
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ if (value != end)
+ goto fail;
+ return acl;
+
+fail:
+ fprintf(stderr, "ACL bad entry\n");
+ free(acl);
+ return NULL;
+}
+
projects / debian / dump / commitdiff