[PATCH 1/3] pkt-line: simplify starts_with checks in packet tracing
- From
Jeff King <peff@peff.net>
- Date
- Jun 12, 2015, 21:28 UTC
- Message-ID
- <20150612212808.GA25757@peff.net>
- In-Reply-To
- <20150612212526.GA25447@peff.net>
We carefully check that our pkt buffer has enough characters before seeing if it starts with "PACK". The intent is to avoid reading random memory if we get a short buffer like "PAC".
However, we know that the traced packets are always NUL-terminated. They come from one of these sources:
1. A string literal.
2. `format_packet`, which uses a strbuf.
3. `packet_read`, which defensively NUL-terminates what we
read.We can therefore drop the length checks, as we know we will hit the trailing NUL if we have a short input.
Signed-off-by: Jeff King <peff@peff.net> --- pkt-line.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/pkt-line.c b/pkt-line.c index 187a229..0477d2e 100644 --- a/pkt-line.c +++ b/pkt-line.c @@ -24,8 +24,7 @@ static void packet_trace(const char *buf, unsigned int len, int write) strbuf_addf(&out, "packet: %12s%c ", packet_trace_prefix, write ? '>' : '<'); - if ((len >= 4 && starts_with(buf, "PACK")) || - (len >= 5 && starts_with(buf+1, "PACK"))) { + if (starts_with(buf, "PACK") || starts_with(buf + 1, "PACK")) { strbuf_addstr(&out, "PACK ..."); trace_disable(&trace_packet); }
-- 2.4.2.752.geeb594a