From e90817a514083345e80b248955e5d3d130561621 Mon Sep 17 00:00:00 2001 From: Aleksander Morgado Date: Wed, 21 Jun 2017 21:13:15 +0200 Subject: ratp: remove bogus data checks in behavior C2 The SN validation was being completely ignored if the packet had no data (e.g. for RST, FIN or SYN or plain ACKs). This condition is now removed so that the SN check is done. The second check removed was actually never being used, as it was already being tested for not having data in the first one. These two fixes are a cleanup to follow the protocol correctly. Signed-off-by: Aleksander Morgado Signed-off-by: Sascha Hauer --- lib/ratp.c | 8 +------- scripts/remote/ratp.py | 16 +++++----------- 2 files changed, 6 insertions(+), 18 deletions(-) diff --git a/lib/ratp.c b/lib/ratp.c index 846f8130cf..321721ab71 100644 --- a/lib/ratp.c +++ b/lib/ratp.c @@ -721,9 +721,6 @@ static int ratp_behaviour_c2(struct ratp_internal *ri, void *pkt) pr_debug("%s\n", __func__); - if (!ratp_has_data(hdr)) - return 0; - if (ratp_sn_expected(ri, hdr)) return 0; @@ -745,9 +742,6 @@ static int ratp_behaviour_c2(struct ratp_internal *ri, void *pkt) return 1; } - if (!ratp_has_data(hdr)) - return 1; - pr_debug("Sending ack for duplicate message\n"); ret = ratp_send_ack(ri, hdr); if (ret) @@ -1846,4 +1840,4 @@ eor: } return 0; -} \ No newline at end of file +} diff --git a/scripts/remote/ratp.py b/scripts/remote/ratp.py index a41d2e8a3f..0dfc8420c7 100644 --- a/scripts/remote/ratp.py +++ b/scripts/remote/ratp.py @@ -339,9 +339,6 @@ class RatpConnection(object): def _c2(self, r): logging.info("C2") - if r.length == 0 and r.c_so == 0: - return True - if r.c_sn != self._r_sn: return True @@ -358,14 +355,11 @@ class RatpConnection(object): self._state = RatpState.closed return False - # FIXME: only ack duplicate data packages? - # This is not documented in RFC 916 - if r.length or r.c_so: - logging.info("C2: duplicate data packet, dropping") - s = RatpPacket(flags='A') - s.c_sn = r.c_an - s.c_an = (r.c_sn + 1) % 2 - self._write(s) + logging.info("C2: duplicate packet") + s = RatpPacket(flags='A') + s.c_sn = r.c_an + s.c_an = (r.c_sn + 1) % 2 + self._write(s) return False -- cgit v1.2.3