cifs: fix dfs domain referrals

The new mount API requires additional changes to how DFS
is handled. Additional testing of DFS uncovered problems
with domain based DFS referrals (a follow on patch addresses
DFS links) which this patch addresses.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 26 insertions, 6 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index c8ef24bac94f..10fe6d6d2dee 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2972,17 +2972,20 @@ expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses,
 	rc = dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
 			    ref_path, &referral, NULL);
 	if (!rc) {
+		char *fake_devname = NULL;
+
 		mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options,
-						   full_path + 1, &referral);
+						   full_path + 1, &referral,
+						   &fake_devname);
 		free_dfs_info_param(&referral);
 
 		if (IS_ERR(mdata)) {
 			rc = PTR_ERR(mdata);
 			mdata = NULL;
 		} else {
-			smb3_cleanup_fs_context_contents(ctx);
-			rc = cifs_setup_volume_info(ctx);
+			rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
 		}
+		kfree(fake_devname);
 		kfree(cifs_sb->ctx->mount_options);
 		cifs_sb->ctx->mount_options = mdata;
 	}
@@ -3036,6 +3039,7 @@ static int setup_dfs_tgt_conn(const char *path, const char *full_path,
 	struct dfs_info3_param ref = {0};
 	char *mdata = NULL;
 	struct smb3_fs_context fake_ctx = {NULL};
+	char *fake_devname = NULL;
 
 	cifs_dbg(FYI, "%s: dfs path: %s\n", __func__, path);
 
@@ -3044,16 +3048,18 @@ static int setup_dfs_tgt_conn(const char *path, const char *full_path,
 		return rc;
 
 	mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options,
-					   full_path + 1, &ref);
+					   full_path + 1, &ref,
+					   &fake_devname);
 	free_dfs_info_param(&ref);
 
 	if (IS_ERR(mdata)) {
 		rc = PTR_ERR(mdata);
 		mdata = NULL;
 	} else
-		rc = cifs_setup_volume_info(&fake_ctx);
+		rc = cifs_setup_volume_info(&fake_ctx, mdata, fake_devname);
 
 	kfree(mdata);
+	kfree(fake_devname);
 
 	if (!rc) {
 		/*
@@ -3122,10 +3128,24 @@ static int do_dfs_failover(const char *path, const char *full_path, struct cifs_
  * we should pass a clone of the original context?
  */
 int
-cifs_setup_volume_info(struct smb3_fs_context *ctx)
+cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
 {
 	int rc = 0;
 
+	smb3_parse_devname(devname, ctx);
+
+	if (mntopts) {
+		char *ip;
+
+		cifs_dbg(FYI, "%s: mntopts=%s\n", __func__, mntopts);
+		rc = smb3_parse_opt(mntopts, "ip", &ip);
+		if (!rc && !cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip,
+						 strlen(ip))) {
+			cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
+			return -EINVAL;
+		}
+	}
+
 	if (ctx->nullauth) {
 		cifs_dbg(FYI, "Anonymous login\n");
 		kfree(ctx->username);