MINOR: quic: refactor packet drop on reception
Sometimes, a packet is dropped on reception. Several goto statements are
used, mostly to increment a proxy drop counter or drop silently the
packet. However, this labels are interleaved. Re-arrang goto labels to
simplify this process :
* drop label is used to drop a packet with counter incrementation. This
is the default method.
* drop_silent is the next label which does the same thing but skip the
counter incrementation. This is useful when we do not need to report
the packet dropping operation.
This should be backported up to 2.6.
diff --git a/src/quic_conn.c b/src/quic_conn.c
index f279501..7c77bfa 100644
--- a/src/quic_conn.c
+++ b/src/quic_conn.c
@@ -6056,7 +6056,7 @@
const unsigned char *beg = buf;
struct proxy *prx;
struct quic_counters *prx_counters;
- int drop_no_conn = 0, long_header = 0;
+ int long_header = 0;
uint32_t version;
const struct quic_version *qv = NULL;
@@ -6083,7 +6083,7 @@
* the remaining space.
*/
pkt->len = end - buf;
- goto drop_no_conn;
+ goto drop_silent;
}
TRACE_PROTO("Packet dropped", QUIC_EV_CONN_LPKT);
@@ -6105,12 +6105,8 @@
goto drop;
}
- if (pkt->type == QUIC_PACKET_TYPE_0RTT && !l->bind_conf->ssl_conf.early_data) {
- TRACE_PROTO("0-RTT packet not supported", QUIC_EV_CONN_LPKT);
- drop_no_conn = 1;
- }
- else if (pkt->type == QUIC_PACKET_TYPE_INITIAL &&
- dgram->len < QUIC_INITIAL_PACKET_MINLEN) {
+ if (pkt->type == QUIC_PACKET_TYPE_INITIAL &&
+ dgram->len < QUIC_INITIAL_PACKET_MINLEN) {
TRACE_PROTO("Too short datagram with an Initial packet", QUIC_EV_CONN_LPKT);
HA_ATOMIC_INC(&prx_counters->too_short_initial_dgram);
goto drop;
@@ -6138,11 +6134,11 @@
/* unsupported version, send Negotiation packet */
if (send_version_negotiation(l->rx.fd, &dgram->saddr, pkt)) {
TRACE_ERROR("VN packet not sent", QUIC_EV_CONN_LPKT);
- goto err;
+ goto drop_silent;
}
TRACE_PROTO("VN packet sent", QUIC_EV_CONN_LPKT);
- goto err;
+ goto drop_silent;
}
pkt->version = qv;
@@ -6169,11 +6165,11 @@
if (send_retry(l->rx.fd, &dgram->saddr, pkt, qv)) {
TRACE_PROTO("Error during Retry generation",
QUIC_EV_CONN_LPKT, NULL, NULL, NULL, qv);
- goto err;
+ goto drop_silent;
}
HA_ATOMIC_INC(&prx_counters->retry_sent);
- goto err;
+ goto drop_silent;
}
}
else if (!global.cluster_secret && token_len) {
@@ -6209,8 +6205,15 @@
*/
pkt->pn_offset = buf - beg;
pkt->len = pkt->pn_offset + len;
- if (drop_no_conn)
- goto drop_no_conn;
+
+ /* Interrupt parsing after packet length retrieval : this
+ * ensures that only the packet is dropped but not the whole
+ * datagram.
+ */
+ if (pkt->type == QUIC_PACKET_TYPE_0RTT && !l->bind_conf->ssl_conf.early_data) {
+ TRACE_PROTO("0-RTT packet not supported", QUIC_EV_CONN_LPKT);
+ goto drop;
+ }
}
else {
TRACE_PROTO("short header packet received", QUIC_EV_CONN_LPKT);
@@ -6242,17 +6245,9 @@
TRACE_LEAVE(QUIC_EV_CONN_LPKT, NULL, pkt, NULL, qv);
return 0;
- drop_no_conn:
- if (drop_no_conn)
- HA_ATOMIC_INC(&prx_counters->dropped_pkt);
- TRACE_LEAVE(QUIC_EV_CONN_LPKT, NULL, pkt);
-
- return -1;
-
drop:
HA_ATOMIC_INC(&prx_counters->dropped_pkt);
-
- err:
+ drop_silent:
if (!pkt->len)
pkt->len = end - beg;
TRACE_LEAVE(QUIC_EV_CONN_LPKT, NULL, pkt, NULL, qv);
@@ -6336,7 +6331,7 @@
TRACE_PROTO("Packet dropped",
QUIC_EV_CONN_LPKT, qc, NULL, NULL, qv);
HA_ATOMIC_INC(&qc->prx_counters->dropped_pkt_bufoverrun);
- goto drop_no_conn;
+ goto drop_silent;
}
/* Let us consume the remaining contiguous space. */
@@ -6349,7 +6344,7 @@
TRACE_PROTO("Too big packet",
QUIC_EV_CONN_LPKT, qc, pkt, &pkt->len, qv);
HA_ATOMIC_INC(&qc->prx_counters->dropped_pkt_bufoverrun);
- goto drop_no_conn;
+ goto drop_silent;
}
}
@@ -6365,7 +6360,7 @@
*tasklist_head = tasklet_wakeup_after(*tasklist_head,
qc->wait_event.tasklet);
- drop_no_conn:
+ drop_silent:
TRACE_LEAVE(QUIC_EV_CONN_LPKT, qc ? qc : NULL, pkt, NULL, qv);
return;