MINOR: quic: Store the next connection IDs sequence number in the connection

Add ->next_cid_seq_num new member to quic_conn struct to store the next
connection ID to be used to alloacated a connection ID.
It is initialized to 0 from qc_new_conn() which initializes a connection.
Modify new_quic_cid() to use this variable each time it is called without
giving the possibility to the caller to pass the sequence number for the
connection to be allocated.

Modify quic_build_post_handshake_frames() to use ->next_cid_seq_num
when building NEW_CONNECTION_ID frames after the hanshake has been completed.
Limit the number of connection IDs provided to the peer to the minimum
between 4 and the value it sent with active_connection_id_limit transport
parameter. This includes the connection ID used by the connection to send
this new connection IDs.

Must be backported to 2.7.

diff --git a/include/haproxy/quic_conn-t.h b/include/haproxy/quic_conn-t.h
index 9c3d4f4ba7216b48e019bbe6b0da6e6810f5fca6..e302fb59f5d5ba02b270c4f505be76167618b5e1 100644 (file)
--- a/include/haproxy/quic_conn-t.h
+++ b/include/haproxy/quic_conn-t.h
@@ -656,6 +656,7 @@ struct quic_conn {
        struct ebmb_node scid_node; /* used only for client side (backend) */
        struct quic_cid scid; /* first SCID of our endpoint - not updated when a new SCID is used */
        struct eb_root cids; /* tree of quic_connection_id - used to match a received packet DCID with a connection */
+       uint64_t next_cid_seq_num;
 
        struct quic_enc_level els[QUIC_TLS_ENC_LEVEL_MAX];
        struct quic_pktns pktns[QUIC_TLS_PKTNS_MAX];

diff --git a/src/quic_conn.c b/src/quic_conn.c
index d8ae0385c6a2228e906fb4c78af419d9170059bb..80d80f2862942c56accc1a09a0652bae5716a3a4 100644 (file)
--- a/src/quic_conn.c
+++ b/src/quic_conn.c
@@ -3725,8 +3725,7 @@ static int quic_stateless_reset_token_init(struct quic_conn *qc,
        return ret;
 }
 
-/* Allocate a new CID with <seq_num> as sequence number and attach it to <root>
- * ebtree.
+/* Allocate a new CID and attach it to <root> ebtree.
  *
  * The CID is randomly generated in part with the result altered to be
  * associated with the current thread ID. This means this function must only
@@ -3735,8 +3734,7 @@ static int quic_stateless_reset_token_init(struct quic_conn *qc,
  * Returns the new CID if succeeded, NULL if not.
  */
 static struct quic_connection_id *new_quic_cid(struct eb_root *root,
-                                               struct quic_conn *qc,
-                                               int seq_num)
+                                               struct quic_conn *qc)
 {
        struct quic_connection_id *cid;
 
@@ -3763,7 +3761,7 @@ static struct quic_connection_id *new_quic_cid(struct eb_root *root,
 
        cid->qc = qc;
 
-       cid->seq_num.key = seq_num;
+       cid->seq_num.key = qc->next_cid_seq_num++;
        cid->retire_prior_to = 0;
        /* insert the allocated CID in the quic_conn tree */
        eb64_insert(root, &cid->seq_num);
@@ -3784,7 +3782,7 @@ static struct quic_connection_id *new_quic_cid(struct eb_root *root,
  */
 static int quic_build_post_handshake_frames(struct quic_conn *qc)
 {
-       int ret = 0, i, first, max;
+       int ret = 0, max;
        struct quic_enc_level *qel;
        struct quic_frame *frm, *frmbak;
        struct list frm_list = LIST_HEAD_INIT(frm_list);
@@ -3805,13 +3803,14 @@ static int quic_build_post_handshake_frames(struct quic_conn *qc)
        }
 
        /* Initialize <max> connection IDs minus one: there is
-        * already one connection ID used for the current connection.
+        * already one connection ID used for the current connection. Also limit
+        * the number of connection IDs sent to the peer to 4 (3 from this function
+        * plus 1 for the current connection.
+        * Note that active_connection_id_limit >= 2: this has been already checked
+        * when receiving this parameter.
         */
-       first = 1;
-       max = qc->tx.params.active_connection_id_limit;
-
-       /* TODO: check limit */
-       for (i = first; i < max; i++) {
+       max = QUIC_MIN(qc->tx.params.active_connection_id_limit - 1, (uint64_t)3);
+       while (max--) {
                struct quic_connection_id *cid;
 
                frm = qc_frm_alloc(QUIC_FT_NEW_CONNECTION_ID);
@@ -3820,7 +3819,7 @@ static int quic_build_post_handshake_frames(struct quic_conn *qc)
                        goto err;
                }
 
-               cid = new_quic_cid(&qc->cids, qc, i);
+               cid = new_quic_cid(&qc->cids, qc);
                if (!cid) {
                        qc_frm_free(&frm);
                        TRACE_ERROR("CID allocation error", QUIC_EV_CONN_IO_CB, qc);
@@ -3847,7 +3846,10 @@ static int quic_build_post_handshake_frames(struct quic_conn *qc)
        list_for_each_entry_safe(frm, frmbak, &frm_list, list)
                qc_frm_free(&frm);
 
-       node = eb64_lookup_ge(&qc->cids, first);
+       /* The first CID sequence number value used to allocated CIDs by this function is 1,
+        * 0 being the sequence number of the CID for this connection.
+        */
+       node = eb64_lookup_ge(&qc->cids, 1);
        while (node) {
                struct quic_connection_id *cid;
 
@@ -5179,7 +5181,10 @@ static struct quic_conn *qc_new_conn(const struct quic_version *qv, int ipv4,
        qc->mux_state = QC_MUX_NULL;
        qc->err = quic_err_transport(QC_ERR_NO_ERROR);
 
-       icid = new_quic_cid(&qc->cids, qc, 0);
+       /* Initialize the next CID sequence number to be used for this connection. */
+       qc->next_cid_seq_num = 0;
+       /* Insert the CID for this connection with 0 as sequence number. */
+       icid = new_quic_cid(&qc->cids, qc);
        if (!icid) {
                TRACE_ERROR("Could not allocate a new connection ID", QUIC_EV_CONN_INIT, qc);
                goto err;