From: Jeremy Allison <jra@samba.org>
Date: Thu, 3 Feb 2022 19:15:30 +0000 (-0800)
Subject: s3: libsmb: Add cli_dfs_target_check() function.
X-Git-Tag: tevent-0.12.0~782
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2abba0ea109d7a3a0b0cb4a7030293f70c2d9d8a;p=thirdparty%2Fsamba.git

s3: libsmb: Add cli_dfs_target_check() function.

Strips any DFS prefix from a target name that will be passed
to an SMB1/2/3 rename or hardlink call. Returns a pointer
into the original target name after the prefix. Not yet used.

If the incoming filename is *NOT* a DFS prefix, the
original filename is returned unchanged.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14169

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Noel Power <npower@samba.org>
---

diff --git a/source3/libsmb/clidfs.c b/source3/libsmb/clidfs.c
index 5b64858ca33..5288a7efc64 100644
--- a/source3/libsmb/clidfs.c
+++ b/source3/libsmb/clidfs.c
@@ -1274,3 +1274,60 @@ bool cli_check_msdfs_proxy(TALLOC_CTX *ctx,
 
 	return true;
 }
+
+/********************************************************************
+ Windows and NetApp (and arguably the SMB1/2/3 specs) expect a non-DFS
+ path for the targets of rename and hardlink. If we have been given
+ a DFS path for these calls, convert it back into a local path by
+ stripping off the DFS prefix.
+********************************************************************/
+
+NTSTATUS cli_dfs_target_check(TALLOC_CTX *mem_ctx,
+			struct cli_state *cli,
+			const char *fname_src,
+			const char *fname_dst,
+			const char **fname_dst_out)
+{
+	char *dfs_prefix = NULL;
+	size_t prefix_len = 0;
+	struct smbXcli_tcon *tcon = NULL;
+
+	if (!smbXcli_conn_dfs_supported(cli->conn)) {
+		goto copy_fname_out;
+	}
+	if (smbXcli_conn_protocol(cli->conn) >= PROTOCOL_SMB2_02) {
+		tcon = cli->smb2.tcon;
+	} else {
+		tcon = cli->smb1.tcon;
+	}
+	if (!smbXcli_tcon_is_dfs_share(tcon)) {
+		goto copy_fname_out;
+	}
+	dfs_prefix = cli_dfs_make_full_path(mem_ctx, cli, "");
+	if (dfs_prefix == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+	prefix_len = strlen(dfs_prefix);
+	if (strncmp(fname_dst, dfs_prefix, prefix_len) != 0) {
+		/*
+		 * Prefix doesn't match. Assume it was
+		 * already stripped or not added in the
+		 * first place.
+		 */
+		goto copy_fname_out;
+	}
+	/* Return the trailing name after the prefix. */
+	*fname_dst_out = &fname_dst[prefix_len];
+	TALLOC_FREE(dfs_prefix);
+	return NT_STATUS_OK;
+
+  copy_fname_out:
+
+	/*
+	 * No change to the destination name. Just
+	 * point it at the incoming destination name.
+	 */
+	*fname_dst_out = fname_dst;
+	TALLOC_FREE(dfs_prefix);
+	return NT_STATUS_OK;
+}
diff --git a/source3/libsmb/proto.h b/source3/libsmb/proto.h
index 8a32d4b7c2d..bda4058dafe 100644
--- a/source3/libsmb/proto.h
+++ b/source3/libsmb/proto.h
@@ -160,6 +160,12 @@ bool cli_check_msdfs_proxy(TALLOC_CTX *ctx,
 			char **pp_newshare,
 			struct cli_credentials *creds);
 
+NTSTATUS cli_dfs_target_check(TALLOC_CTX *mem_ctx,
+			struct cli_state *cli,
+			const char *fname_src,
+			const char *fname_dst,
+			const char **fname_dst_out);
+
 /* The following definitions come from libsmb/clientgen.c  */
 
 unsigned int cli_set_timeout(struct cli_state *cli, unsigned int timeout);