MEDIUM: quic: implement Initial token parsing
Implement the parsing of token from Initial packets. It is expected that
the token contains a CID which is the DCID from the Initial packet
received from the client without token which triggers a Retry packet.
This CID is then used for transport parameters.
Note that at the moment Retry packet emission is not implemented. This
will be achieved in a following commit.
diff --git a/include/haproxy/xprt_quic-t.h b/include/haproxy/xprt_quic-t.h
index 06c43fe..78ced51 100644
--- a/include/haproxy/xprt_quic-t.h
+++ b/include/haproxy/xprt_quic-t.h
@@ -435,6 +435,7 @@
/* Packet number length */
uint32_t pnl;
uint64_t token_len;
+ const unsigned char *token;
/* Packet length */
uint64_t len;
/* Packet length before decryption */
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 558e704..6cf0d4b 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -4046,6 +4046,25 @@
return qc;
}
+/* Parse the Retry token from buffer <token> whose size is <token_len>. This
+ * will extract the parameters stored in the token : <odcid>.
+ *
+ * Returns 0 on success else non-zero.
+ */
+static int parse_retry_token(const unsigned char *token, uint64_t token_len,
+ struct quic_cid *odcid)
+{
+ uint64_t odcid_len;
+
+ if (!quic_dec_int(&odcid_len, &token, token + token_len))
+ return 1;
+
+ memcpy(odcid->data, token, odcid_len);
+ odcid->len = odcid_len;
+
+ return 0;
+}
+
static ssize_t qc_lstnr_pkt_rcv(unsigned char *buf, const unsigned char *end,
struct quic_rx_packet *pkt,
struct quic_dgram_ctx *dgram_ctx,
@@ -4127,6 +4146,10 @@
* The token must be provided in a Retry packet or NEW_TOKEN frame.
*/
pkt->token_len = token_len;
+ if (pkt->token_len) {
+ pkt->token = buf;
+ buf += pkt->token_len;
+ }
}
else if (pkt->type != QUIC_PACKET_TYPE_0RTT) {
if (pkt->dcid.len != QUIC_HAP_CID_LEN) {
@@ -4168,9 +4191,19 @@
odcid = &qc->rx.params.original_destination_connection_id;
/* Copy the transport parameters. */
qc->rx.params = l->bind_conf->quic_params;
+
/* Copy original_destination_connection_id transport parameter. */
- memcpy(odcid->data, &pkt->dcid.data, pkt->dcid.len);
- odcid->len = pkt->dcid.len;
+ if (pkt->token_len) {
+ if (parse_retry_token(pkt->token, pkt->token_len, odcid)) {
+ TRACE_PROTO("Error during Initial token parsing", QUIC_EV_CONN_LPKT, qc);
+ goto err;
+ }
+ }
+ else {
+ memcpy(odcid->data, &pkt->dcid.data, pkt->dcid.len);
+ odcid->len = pkt->dcid.len;
+ }
+
/* Copy the initial source connection ID. */
quic_cid_cpy(&qc->rx.params.initial_source_connection_id, &qc->scid);
qc->enc_params_len =