BUG/MINOR: mux-h2: refuse to allocate a stream with too high an ID

One of the reasons for the excessive number of aborted requests when a
server sets a limit on the highest stream ID is that we don't check
this limit while allocating a new stream.

This patch does this at two locations :
  - when a backend stream is allocated, we verify that there are still
    IDs left ;
  - when the ID is assigned, we verify that it's not higher than the
    advertised limit.

This should be backported to 1.9.
This commit is contained in:
Willy Tarreau 2019-01-24 17:08:28 +01:00
parent d64a3ebe64
commit a80dca8535

View File

@ -547,7 +547,8 @@ static int h2_init(struct connection *conn, struct proxy *prx, struct session *s
static inline int32_t h2c_get_next_sid(const struct h2c *h2c)
{
int32_t id = (h2c->max_id + 1) | 1;
if (id & 0x80000000U)
if ((id & 0x80000000U) || (h2c->last_sid >= 0 && id > h2c->last_sid))
id = -1;
return id;
}
@ -954,6 +955,9 @@ static struct h2s *h2c_bck_stream_new(struct h2c *h2c, struct conn_stream *cs, s
if (h2c->nb_streams >= h2_settings_max_concurrent_streams)
goto out;
if (h2_streams_left(h2c) < 1)
goto out;
/* Defer choosing the ID until we send the first message to create the stream */
h2s = h2s_new(h2c, 0);
if (!h2s)