From:   Luis Gerhorst <gerhorst@cs.fau.de>
To:     Quentin Monnet <quentin@isovalent.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        Stanislav Fomichev <sdf@google.com>,
        Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>,
        bpf@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Luis Gerhorst <gerhorst@cs.fau.de>
Subject: [PATCH] tools: bpftool: remove invalid \' json escape
Date:   Mon, 27 Feb 2023 16:08:54 +0100
Message-Id: <20230227150853.16863-1-gerhorst@cs.fau.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

RFC8259 ("The JavaScript Object Notation (JSON) Data Interchange
Format") only specifies \", \\, \/, \b, \f, \n, \r, and \r as valid
two-character escape sequences. This does not include \', which is not
required in JSON because it exclusively uses double quotes as string
separators.

Solidus (/) may be escaped, but does not have to. Only reverse
solidus (\), double quotes ("), and the control characters have to be
escaped. Therefore, with this fix, bpftool correctly supports all valid
two-character escape sequences (but still does not support characters
that require multi-character escape sequences).

Witout this fix, attempting to load a JSON file generated by bpftool
using Python 3.10.6's default json.load() may fail with the error
"Invalid \escape" if the file contains the invalid escaped single
quote (\').

Signed-off-by: Luis Gerhorst <gerhorst@cs.fau.de>
---
 tools/bpf/bpftool/json_writer.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/tools/bpf/bpftool/json_writer.c b/tools/bpf/bpftool/json_writer.c
index 7fea83bedf48..bca5dd0a59e3 100644
--- a/tools/bpf/bpftool/json_writer.c
+++ b/tools/bpf/bpftool/json_writer.c
@@ -80,9 +80,6 @@ static void jsonw_puts(json_writer_t *self, const char *str)
 		case '"':
 			fputs("\\\"", self->out);
 			break;
-		case '\'':
-			fputs("\\\'", self->out);
-			break;
 		default:
 			putc(*str, self->out);
 		}
-- 
2.34.1