Add support for DFS in SMB2+

index f5b8730..1ce733f 100644
@@ -2086,17 +2086,21 @@ typedef struct dfs_referral_level_3 { /* version 4 is same, + one flag bit */
 	__u8   ServiceSiteGuid[16];  /* MBZ, ignored */
 } __attribute__((packed)) REFERRAL3;
 
-typedef struct smb_com_transaction_get_dfs_refer_rsp {
-	struct smb_hdr hdr;	/* wct = 10 */
-	struct trans2_resp t2;
-	__u16 ByteCount;
-	__u8 Pad;
+struct get_dfs_referral_rsp {
 	__le16 PathConsumed;
 	__le16 NumberOfReferrals;
 	__le32 DFSFlags;
 	REFERRAL3 referrals[1];	/* array of level 3 dfs_referral structures */
 	/* followed by the strings pointed to by the referral structures */
-} __attribute__((packed)) TRANSACTION2_GET_DFS_REFER_RSP;
+} __packed;
+
+typedef struct smb_com_transaction_get_dfs_refer_rsp {
+	struct smb_hdr hdr;	/* wct = 10 */
+	struct trans2_resp t2;
+	__u16 ByteCount;
+	__u8 Pad;
+	struct get_dfs_referral_rsp dfs_data;
+} __packed TRANSACTION2_GET_DFS_REFER_RSP;
 
 /* DFS Flags */
 #define DFSREF_REFERRAL_SERVER  0x00000001 /* all targets are DFS roots */

index 406d2c1..c097830 100644
@@ -284,6 +284,11 @@ extern int get_dfs_path(const unsigned int xid, struct cifs_ses *ses,
 			const struct nls_table *nls_codepage,
 			unsigned int *num_referrals,
 			struct dfs_info3_param **referrals, int remap);
+extern int parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
+			       unsigned int *num_of_nodes,
+			       struct dfs_info3_param **target_nodes,
+			       const struct nls_table *nls_codepage, int remap,
+			       const char *searchName, bool is_unicode);
 extern void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
 				 struct cifs_sb_info *cifs_sb,
 				 struct smb_vol *vol);

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108 lines not on this page · raw message

index ec9dbbc..8a9ebfd 100644
@@ -302,7 +302,9 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
 	 * gives us the latter, so we must adjust the result.
 	 */
 	mnt = ERR_PTR(-ENOMEM);
-	full_path = build_path_from_dentry(mntpt);
+
+	/* always use tree name prefix */
+	full_path = build_path_from_dentry_optional_prefix(mntpt, true);
 	if (full_path == NULL)
 		goto cdda_exit;
 

index c097830..9ee46c1 100644
@@ -61,6 +61,8 @@ extern void exit_cifs_idmap(void);
 extern int init_cifs_spnego(void);
 extern void exit_cifs_spnego(void);
 extern char *build_path_from_dentry(struct dentry *);
+extern char *build_path_from_dentry_optional_prefix(struct dentry *direntry,
+						    bool prefix);
 extern char *cifs_build_path_to_root(struct smb_vol *vol,
 				     struct cifs_sb_info *cifs_sb,
 				     struct cifs_tcon *tcon,

index 2c227a9..56366e9 100644
@@ -81,6 +81,17 @@ cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb,
 char *
 build_path_from_dentry(struct dentry *direntry)
 {
+	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
+	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
+	bool prefix = tcon->Flags & SMB_SHARE_IS_IN_DFS;
+
+	return build_path_from_dentry_optional_prefix(direntry,
+						      prefix);
+}
+
+char *
+build_path_from_dentry_optional_prefix(struct dentry *direntry, bool prefix)
+{
 	struct dentry *temp;
 	int namelen;
 	int dfsplen;

@@ -92,7 +103,7 @@ build_path_from_dentry(struct dentry *direntry)
 	unsigned seq;
 
 	dirsep = CIFS_DIR_SEP(cifs_sb);
-	if (tcon->Flags & SMB_SHARE_IS_IN_DFS)
+	if (prefix)
 		dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
 	else
 		dfsplen = 0;

index a44b4db..2563fe8 100644
@@ -1097,6 +1097,78 @@ 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 = -EINVAL;
+	__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.
+	 */
+	tcon = list_first_entry(&ses->tcon_list, struct cifs_tcon, tcon_list);
+	if (!tcon)
+		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 = cpu_to_le16(DFS_VERSION);
+
+	/* Path to resolve in an UTF-16 null-terminated string */
+	memcpy(dfs_req->RequestFileName, utf16_path, utf16_path_len);
+
+	do {
+		rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
+				FSCTL_DFS_GET_REFERRALS, true /* is_fsctl */,
+				(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:
+	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))
 

index c03b252..18700fd 100644
@@ -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;

index ad83b3d..c9a1d71 100644
@@ -1167,8 +1167,8 @@ SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
 
 		/* since no tcon, smb2_init can not do this, so do here */
 		req->hdr.sync_hdr.SessionId = ses->Suid;
-		/* if (ses->server->sec_mode & SECMODE_SIGN_REQUIRED)
-			req->hdr.Flags |= SMB2_FLAGS_SIGNED; */
+		if (ses->server->sign)
+			req->hdr.sync_hdr.Flags |= SMB2_FLAGS_SIGNED;
 	} else if (encryption_required(tcon))
 		flags |= CIFS_TRANSFORM_REQ;
 

index c9a1d71..9e9f449 100644
@@ -1527,6 +1527,48 @@ add_durable_context(struct kvec *iov, unsigned int *num_iovec,
 	return 0;
 }
 
+static int
+alloc_path_with_tree_prefix(__le16 **out_path, int *out_size, int *out_len,
+			    const char *treename, const __le16 *path)
+{
+	int treename_len, path_len;
+	const __le16 sep[] = {cpu_to_le16('\\'), cpu_to_le16(0x0000)};
+
+	/*
+	 * skip leading "\\"
+	 */
+	treename_len = strlen(treename);
+	if (treename_len < 2 || !(treename[0] == '\\' && treename[1] == '\\'))
+		return -EINVAL;
+
+	treename += 2;
+	treename_len -= 2;
+
+	path_len = UniStrnlen((wchar_t *)path, PATH_MAX);
+
+	/*
+	 * make room for one path separator between the treename and
+	 * path
+	 */
+	*out_len = treename_len + 1 + path_len;
+
+	/*
+	 * final path needs to be null-terminated UTF16 with a
+	 * size aligned to 8
+	 */
+
+	*out_size = roundup((*out_len+1)*2, 8);
+	*out_path = kzalloc(*out_size, GFP_KERNEL);
+	if (!*out_path)
+		return -ENOMEM;
+
+	cifs_strtoUTF16(*out_path, treename, treename_len, load_nls_default());
+	UniStrcat(*out_path, sep);
+	UniStrcat(*out_path, path);
+
+	return 0;
+}
+
 int
 SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
 	  __u8 *oplock, struct smb2_file_all_info *buf,

@@ -1575,30 +1617,49 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
 	req->ShareAccess = FILE_SHARE_ALL_LE;
 	req->CreateDisposition = cpu_to_le32(oparms->disposition);
 	req->CreateOptions = cpu_to_le32(oparms->create_options & CREATE_OPTIONS_MASK);
-	uni_path_len = (2 * UniStrnlen((wchar_t *)path, PATH_MAX)) + 2;
-	/* do not count rfc1001 len field */
-	req->NameOffset = cpu_to_le16(sizeof(struct smb2_create_req) - 4);
 
 	iov[0].iov_base = (char *)req;
 	/* 4 for rfc1002 length field */
 	iov[0].iov_len = get_rfc1002_length(req) + 4;
-
-	/* MUST set path len (NameLength) to 0 opening root of share */
-	req->NameLength = cpu_to_le16(uni_path_len - 2);
 	/* -1 since last byte is buf[0] which is sent below (path) */
 	iov[0].iov_len--;
-	if (uni_path_len % 8 != 0) {
-		copy_size = uni_path_len / 8 * 8;
-		if (copy_size < uni_path_len)
-			copy_size += 8;
-
-		copy_path = kzalloc(copy_size, GFP_KERNEL);
-		if (!copy_path)
-			return -ENOMEM;
-		memcpy((char *)copy_path, (const char *)path,
-			uni_path_len);
+
+	req->NameOffset = cpu_to_le16(sizeof(struct smb2_create_req) - 4);
+
+	/* [MS-SMB2] 2.2.13 NameOffset:
+	 * If SMB2_FLAGS_DFS_OPERATIONS is set in the Flags field of
+	 * the SMB2 header, the file name includes a prefix that will
+	 * be processed during DFS name normalization as specified in
+	 * section 3.3.5.9. Otherwise, the file name is relative to
+	 * the share that is identified by the TreeId in the SMB2
+	 * header.
+	 */
+	if (tcon->share_flags & SHI1005_FLAGS_DFS) {
+		int name_len;
+
+		req->hdr.sync_hdr.Flags |= SMB2_FLAGS_DFS_OPERATIONS;
+		rc = alloc_path_with_tree_prefix(&copy_path, &copy_size,
+						 &name_len,
+						 tcon->treeName, path);
+		if (rc)
+			return rc;
+		req->NameLength = cpu_to_le16(name_len * 2);
 		uni_path_len = copy_size;
 		path = copy_path;
+	} else {
+		uni_path_len = (2 * UniStrnlen((wchar_t *)path, PATH_MAX)) + 2;
+		/* MUST set path len (NameLength) to 0 opening root of share */
+		req->NameLength = cpu_to_le16(uni_path_len - 2);
+		if (uni_path_len % 8 != 0) {
+			copy_size = roundup(uni_path_len, 8);
+			copy_path = kzalloc(copy_size, GFP_KERNEL);
+			if (!copy_path)
+				return -ENOMEM;
+			memcpy((char *)copy_path, (const char *)path,
+			       uni_path_len);
+			uni_path_len = copy_size;
+			path = copy_path;
+		}
 	}
 
 	iov[1].iov_len = uni_path_len;

index 2563fe8..1537cc8 100644
@@ -2326,6 +2326,7 @@ 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 = {

@@ -2407,6 +2408,7 @@ 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 = {

@@ -2498,6 +2500,7 @@ 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

@@ -2590,6 +2593,7 @@ 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 */