From 77a39282de6fdc98cad1270c6b5b6105629d5e5a Mon Sep 17 00:00:00 2001
From: Axel Burri <axel@tty0.ch>
Date: Wed, 14 Jul 2021 20:34:40 +0200
Subject: [PATCH] ssh_filter_btrbk.sh: allow quoted files

---
 ssh_filter_btrbk.sh | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/ssh_filter_btrbk.sh b/ssh_filter_btrbk.sh
index a9ace42..c1d47b7 100755
--- a/ssh_filter_btrbk.sh
+++ b/ssh_filter_btrbk.sh
@@ -16,7 +16,9 @@ compress_list="gzip|pigz|bzip2|pbzip2|xz|lzop|lz4|zstd"
 
 # note that the backslash is NOT a metacharacter in a POSIX bracket expression!
 option_match='-[a-zA-Z0-9=-]+'   # matches short as well as long options
-file_match='/[0-9a-zA-Z_@+./-]*' # matches file path (equal to $file_match in btrbk)
+file_match_sane='/[0-9a-zA-Z_@+./-]*' # matches file path (equal to $file_match in btrbk < 0.32.0)
+file_match="/[^']*" # btrbk >= 0.32.0 quotes file arguments: match all but single quote
+file_arg_match="('${file_match}'|${file_match_sane})" # support btrbk < 0.32.0
 
 log_cmd()
 {
@@ -52,13 +54,17 @@ run_cmd()
 reject_filtered_cmd()
 {
     if [[ -n "$restrict_path_list" ]]; then
-	# match any of restrict_path_list with or without trailing slash,
+	# match any of restrict_path_list,
 	# or any file/directory (matching file_match) below restrict_path
-	path_match="(${restrict_path_list})(${file_match})?"
+	path_match="'(${restrict_path_list})(${file_match})?'"
+	path_match_legacy="(${restrict_path_list})(${file_match_sane})?"
     else
 	# match any absolute file/directory (matching file_match)
-	path_match="${file_match}"
+	path_match="'${file_match}'"
+	path_match_legacy="${file_match_sane}"
     fi
+    # btrbk >= 0.32.0 quotes files, allow both (legacy)
+    path_match="(${path_match}|${path_match_legacy})"
 
     if [[ -n "$allow_compress" ]]; then
         decompress_match="(${compress_list}) -d -c( -[pT][0-9]+)?"
@@ -163,9 +169,9 @@ done
 
 # NOTE: subvolume queries are NOT affected by "--restrict-path":
 # btrbk also calls show/list on the mount point of the subvolume
-allow_exact_cmd "${sudo_prefix}btrfs subvolume (show|list)( ${option_match})* ${file_match}";
+allow_exact_cmd "${sudo_prefix}btrfs subvolume (show|list)( ${option_match})* ${file_arg_match}";
 allow_cmd "${sudo_prefix}readlink"                    # resolve symlink
-allow_exact_cmd "${sudo_prefix}test -d ${file_match}" # check directory (only for compat=busybox)
+allow_exact_cmd "${sudo_prefix}test -d ${file_arg_match}" # check directory (only for compat=busybox)
 allow_exact_cmd "cat /proc/self/mountinfo"            # resolve mountpoints
 allow_exact_cmd "cat /proc/self/mounts"               # legacy, for btrbk < 0.27.0