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authorAurelien Aptel <aaptel@suse.com>2017-02-13 16:16:49 +0100
committerSteve French <smfrench@gmail.com>2017-03-02 17:05:31 -0600
commit9d49640a21bffd730a6ebf2a0032e022f7caf84a (patch)
treeb51c69ef2ec32de0b10a53da889bdbb7f9adda9e
parentf0712928be1a66c99c35f871b4df7fa23ec1574a (diff)
CIFS: implement get_dfs_refer for SMB2+
in SMB2+ the get_dfs_refer operation uses a FSCTL. The request can be made on any Tree Connection according to the specs. Since Samba only accepted it on an IPC connection until recently, try that first. https://lists.samba.org/archive/samba-technical/2017-February/118859.html 3.2.4.20.3 Application Requests DFS Referral Information: > The client MUST search for an existing Session and TreeConnect to any > share on the server identified by ServerName for the user identified by > UserCredentials. If no Session and TreeConnect are found, the client > MUST establish a new Session and TreeConnect to IPC$ on the target > server as described in section 3.2.4.2 using the supplied ServerName and > UserCredentials. Signed-off-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <smfrench@gmail.com>
-rw-r--r--fs/cifs/smb2ops.c101
-rw-r--r--fs/cifs/smb2pdu.h8
2 files changed, 109 insertions, 0 deletions
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index eba00cd3bd16..b360c381b00e 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -1104,6 +1104,103 @@ smb2_new_lease_key(struct cifs_fid *fid)
generate_random_uuid(fid->lease_key);
}
+static int
+smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses,
+ const char *search_name,
+ struct dfs_info3_param **target_nodes,
+ unsigned int *num_of_nodes,
+ const struct nls_table *nls_codepage, int remap)
+{
+ int rc;
+ __le16 *utf16_path = NULL;
+ int utf16_path_len = 0;
+ struct cifs_tcon *tcon;
+ struct fsctl_get_dfs_referral_req *dfs_req = NULL;
+ struct get_dfs_referral_rsp *dfs_rsp = NULL;
+ u32 dfs_req_size = 0, dfs_rsp_size = 0;
+
+ cifs_dbg(FYI, "smb2_get_dfs_refer path <%s>\n", search_name);
+
+ /*
+ * Use any tcon from the current session. Here, the first one.
+ */
+ spin_lock(&cifs_tcp_ses_lock);
+ tcon = list_first_entry_or_null(&ses->tcon_list, struct cifs_tcon,
+ tcon_list);
+ if (tcon)
+ tcon->tc_count++;
+ spin_unlock(&cifs_tcp_ses_lock);
+
+ if (!tcon) {
+ cifs_dbg(VFS, "session %p has no tcon available for a dfs referral request\n",
+ ses);
+ rc = -ENOTCONN;
+ goto out;
+ }
+
+ utf16_path = cifs_strndup_to_utf16(search_name, PATH_MAX,
+ &utf16_path_len,
+ nls_codepage, remap);
+ if (!utf16_path) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ dfs_req_size = sizeof(*dfs_req) + utf16_path_len;
+ dfs_req = kzalloc(dfs_req_size, GFP_KERNEL);
+ if (!dfs_req) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ /* Highest DFS referral version understood */
+ dfs_req->MaxReferralLevel = DFS_VERSION;
+
+ /* Path to resolve in an UTF-16 null-terminated string */
+ memcpy(dfs_req->RequestFileName, utf16_path, utf16_path_len);
+
+ do {
+ /* try first with IPC */
+ rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
+ FSCTL_DFS_GET_REFERRALS,
+ true /* is_fsctl */, true /* use_ipc */,
+ (char *)dfs_req, dfs_req_size,
+ (char **)&dfs_rsp, &dfs_rsp_size);
+ if (rc == -ENOTCONN) {
+ /* try with normal tcon */
+ rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
+ FSCTL_DFS_GET_REFERRALS,
+ true /* is_fsctl */, false /*use_ipc*/,
+ (char *)dfs_req, dfs_req_size,
+ (char **)&dfs_rsp, &dfs_rsp_size);
+ }
+ } while (rc == -EAGAIN);
+
+ if (rc) {
+ cifs_dbg(VFS, "ioctl error in smb2_get_dfs_refer rc=%d\n", rc);
+ goto out;
+ }
+
+ rc = parse_dfs_referrals(dfs_rsp, dfs_rsp_size,
+ num_of_nodes, target_nodes,
+ nls_codepage, remap, search_name,
+ true /* is_unicode */);
+ if (rc) {
+ cifs_dbg(VFS, "parse error in smb2_get_dfs_refer rc=%d\n", rc);
+ goto out;
+ }
+
+ out:
+ if (tcon) {
+ spin_lock(&cifs_tcp_ses_lock);
+ tcon->tc_count--;
+ spin_unlock(&cifs_tcp_ses_lock);
+ }
+ kfree(utf16_path);
+ kfree(dfs_req);
+ kfree(dfs_rsp);
+ return rc;
+}
#define SMB2_SYMLINK_STRUCT_SIZE \
(sizeof(struct smb2_err_rsp) - 1 + sizeof(struct smb2_symlink_err_rsp))
@@ -2283,6 +2380,7 @@ struct smb_version_operations smb20_operations = {
.clone_range = smb2_clone_range,
.wp_retry_size = smb2_wp_retry_size,
.dir_needs_close = smb2_dir_needs_close,
+ .get_dfs_refer = smb2_get_dfs_refer,
};
struct smb_version_operations smb21_operations = {
@@ -2364,6 +2462,7 @@ struct smb_version_operations smb21_operations = {
.wp_retry_size = smb2_wp_retry_size,
.dir_needs_close = smb2_dir_needs_close,
.enum_snapshots = smb3_enum_snapshots,
+ .get_dfs_refer = smb2_get_dfs_refer,
};
struct smb_version_operations smb30_operations = {
@@ -2455,6 +2554,7 @@ struct smb_version_operations smb30_operations = {
.free_transform_rq = smb3_free_transform_rq,
.is_transform_hdr = smb3_is_transform_hdr,
.receive_transform = smb3_receive_transform,
+ .get_dfs_refer = smb2_get_dfs_refer,
};
#ifdef CONFIG_CIFS_SMB311
@@ -2547,6 +2647,7 @@ struct smb_version_operations smb311_operations = {
.free_transform_rq = smb3_free_transform_rq,
.is_transform_hdr = smb3_is_transform_hdr,
.receive_transform = smb3_receive_transform,
+ .get_dfs_refer = smb2_get_dfs_refer,
};
#endif /* CIFS_SMB311 */
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index c03b252501a1..18700fd25a0b 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -695,6 +695,14 @@ struct fsctl_get_integrity_information_rsp {
/* Integrity flags for above */
#define FSCTL_INTEGRITY_FLAG_CHECKSUM_ENFORCEMENT_OFF 0x00000001
+/* See MS-DFSC 2.2.2 */
+struct fsctl_get_dfs_referral_req {
+ __le16 MaxReferralLevel;
+ __u8 RequestFileName[];
+} __packed;
+
+/* DFS response is struct get_dfs_refer_rsp */
+
/* See MS-SMB2 2.2.31.3 */
struct network_resiliency_req {
__le32 Timeout;