From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Mon, 24 Oct 2022 08:03:33 +0000 (+0200)
Subject: MINOR: quic: do not crash on unhandled sendto error
X-Git-Tag: v2.7-dev9~140
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1d9f170eddd8703ba550e91322298e88e8280075;p=thirdparty%2Fhaproxy.git

MINOR: quic: do not crash on unhandled sendto error

Remove ABORT_NOW() statement on unhandled sendto error. Instead use a
dedicated counter sendto_err_unknown to report these cases.

If we detect increment of this counter, strace can be used to detect
errno value :
  $ strace -p $(pidof haproxy) -f -e trace=sendto -Z

This should be backported up to 2.6.

This should help to debug github issue #1903.
---

diff --git a/include/haproxy/quic_stats-t.h b/include/haproxy/quic_stats-t.h
index 8a682285c7..707825e4ad 100644
--- a/include/haproxy/quic_stats-t.h
+++ b/include/haproxy/quic_stats-t.h
@@ -56,6 +56,7 @@ struct quic_counters {
 	long long dropped_parsing;   /* total number of dropped packets upon parsing errors */
 	long long socket_full;       /* total number of EAGAIN errors on sendto() calls */
 	long long sendto_err;        /* total number of errors on sendto() calls, EAGAIN excepted */
+	long long sendto_err_unknown; /* total number of errors on sendto() calls which are currently not supported */
 	long long lost_pkt;          /* total number of lost packets */
 	long long too_short_initial_dgram; /* total number of too short datagrams with Initial packets */
 	long long retry_sent;        /* total number of Retry sent */
diff --git a/src/quic_sock.c b/src/quic_sock.c
index 8617489203..29f30ccbe0 100644
--- a/src/quic_sock.c
+++ b/src/quic_sock.c
@@ -536,14 +536,14 @@ int qc_snd_buf(struct quic_conn *qc, const struct buffer *buf, size_t sz,
 	} while (ret < 0 && errno == EINTR);
 
 	if (ret < 0 || ret != sz) {
+		struct proxy *prx = qc->li->bind_conf->frontend;
+		struct quic_counters *prx_counters =
+		  EXTRA_COUNTERS_GET(prx->extra_counters_fe,
+		                     &quic_stats_module);
+
 		/* TODO adjust errno for UDP context. */
 		if (errno == EAGAIN || errno == EWOULDBLOCK ||
 		    errno == ENOTCONN || errno == EINPROGRESS || errno == EBADF) {
-			struct proxy *prx = qc->li->bind_conf->frontend;
-			struct quic_counters *prx_counters =
-			  EXTRA_COUNTERS_GET(prx->extra_counters_fe,
-			                     &quic_stats_module);
-
 			if (errno == EAGAIN || errno == EWOULDBLOCK)
 				HA_ATOMIC_INC(&prx_counters->socket_full);
 			else
@@ -551,7 +551,7 @@ int qc_snd_buf(struct quic_conn *qc, const struct buffer *buf, size_t sz,
 		}
 		else if (errno) {
 			/* TODO unlisted errno : handle it explicitly. */
-			ABORT_NOW();
+			HA_ATOMIC_INC(&prx_counters->sendto_err_unknown);
 		}
 
 		return 1;