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-rw-r--r--fs/cifs/cifsacl.c123
1 files changed, 123 insertions, 0 deletions
diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 71e8a56e9479..15bac390dff9 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -42,6 +42,35 @@ static const struct cifs_sid sid_authusers = {
/* group users */
static const struct cifs_sid sid_user = {1, 2 , {0, 0, 0, 0, 0, 5}, {} };
+/* S-1-22-1 Unmapped Unix users */
+static const struct cifs_sid sid_unix_users = {1, 1, {0, 0, 0, 0, 0, 22},
+ {cpu_to_le32(1), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
+
+/* S-1-22-2 Unmapped Unix groups */
+static const struct cifs_sid sid_unix_groups = { 1, 1, {0, 0, 0, 0, 0, 22},
+ {cpu_to_le32(2), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
+
+/*
+ * See http://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx
+ */
+
+/* S-1-5-88 MS NFS and Apple style UID/GID/mode */
+
+/* S-1-5-88-1 Unix uid */
+static const struct cifs_sid sid_unix_NFS_users = { 1, 2, {0, 0, 0, 0, 0, 5},
+ {cpu_to_le32(88),
+ cpu_to_le32(1), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
+
+/* S-1-5-88-2 Unix gid */
+static const struct cifs_sid sid_unix_NFS_groups = { 1, 2, {0, 0, 0, 0, 0, 5},
+ {cpu_to_le32(88),
+ cpu_to_le32(2), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
+
+/* S-1-5-88-3 Unix mode */
+static const struct cifs_sid sid_unix_NFS_mode = { 1, 2, {0, 0, 0, 0, 0, 5},
+ {cpu_to_le32(88),
+ cpu_to_le32(3), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
+
static const struct cred *root_cred;
static int
@@ -183,6 +212,62 @@ compare_sids(const struct cifs_sid *ctsid, const struct cifs_sid *cwsid)
return 0; /* sids compare/match */
}
+static bool
+is_well_known_sid(const struct cifs_sid *psid, uint32_t *puid, bool is_group)
+{
+ int i;
+ int num_subauth;
+ const struct cifs_sid *pwell_known_sid;
+
+ if (!psid || (puid == NULL))
+ return false;
+
+ num_subauth = psid->num_subauth;
+
+ /* check if Mac (or Windows NFS) vs. Samba format for Unix owner SID */
+ if (num_subauth == 2) {
+ if (is_group)
+ pwell_known_sid = &sid_unix_groups;
+ else
+ pwell_known_sid = &sid_unix_users;
+ } else if (num_subauth == 3) {
+ if (is_group)
+ pwell_known_sid = &sid_unix_NFS_groups;
+ else
+ pwell_known_sid = &sid_unix_NFS_users;
+ } else
+ return false;
+
+ /* compare the revision */
+ if (psid->revision != pwell_known_sid->revision)
+ return false;
+
+ /* compare all of the six auth values */
+ for (i = 0; i < NUM_AUTHS; ++i) {
+ if (psid->authority[i] != pwell_known_sid->authority[i]) {
+ cifs_dbg(FYI, "auth %d did not match\n", i);
+ return false;
+ }
+ }
+
+ if (num_subauth == 2) {
+ if (psid->sub_auth[0] != pwell_known_sid->sub_auth[0])
+ return false;
+
+ *puid = le32_to_cpu(psid->sub_auth[1]);
+ } else /* 3 subauths, ie Windows/Mac style */ {
+ *puid = le32_to_cpu(psid->sub_auth[0]);
+ if ((psid->sub_auth[0] != pwell_known_sid->sub_auth[0]) ||
+ (psid->sub_auth[1] != pwell_known_sid->sub_auth[1]))
+ return false;
+
+ *puid = le32_to_cpu(psid->sub_auth[2]);
+ }
+
+ cifs_dbg(FYI, "Unix UID %d returned from SID\n", *puid);
+ return true; /* well known sid found, uid returned */
+}
+
static void
cifs_copy_sid(struct cifs_sid *dst, const struct cifs_sid *src)
{
@@ -276,6 +361,43 @@ sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid,
return -EIO;
}
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UID_FROM_ACL) {
+ uint32_t unix_id;
+ bool is_group;
+
+ if (sidtype != SIDOWNER)
+ is_group = true;
+ else
+ is_group = false;
+
+ if (is_well_known_sid(psid, &unix_id, is_group) == false)
+ goto try_upcall_to_get_id;
+
+ if (is_group) {
+ kgid_t gid;
+ gid_t id;
+
+ id = (gid_t)unix_id;
+ gid = make_kgid(&init_user_ns, id);
+ if (gid_valid(gid)) {
+ fgid = gid;
+ goto got_valid_id;
+ }
+ } else {
+ kuid_t uid;
+ uid_t id;
+
+ id = (uid_t)unix_id;
+ uid = make_kuid(&init_user_ns, id);
+ if (uid_valid(uid)) {
+ fuid = uid;
+ goto got_valid_id;
+ }
+ }
+ /* If unable to find uid/gid easily from SID try via upcall */
+ }
+
+try_upcall_to_get_id:
sidstr = sid_to_key_str(psid, sidtype);
if (!sidstr)
return -ENOMEM;
@@ -329,6 +451,7 @@ out_revert_creds:
* Note that we return 0 here unconditionally. If the mapping
* fails then we just fall back to using the mnt_uid/mnt_gid.
*/
+got_valid_id:
if (sidtype == SIDOWNER)
fattr->cf_uid = fuid;
else