MINOR: proto_htx: Add function to build and send HTTP 103 responses

It is more or less the same than legacy versions but adapted to be called from
HTX analyzers.

diff --git a/src/proto_htx.c b/src/proto_htx.c
index fda08d65529e945272e5999a92453c23702f469f..83a2c33a4c3ceb42493952e7614603fba6d6cd4c 100644 (file)
--- a/src/proto_htx.c
+++ b/src/proto_htx.c
@@ -2585,6 +2585,63 @@ static int htx_transform_header(struct stream* s, struct channel *chn, struct ht
        return ret;
 }
 
+/*
+ * Build an HTTP Early Hint HTTP 103 response header with <name> as name and with a value
+ * built according to <fmt> log line format.
+ * If <early_hints> is NULL, it is allocated and the HTTP 103 response first
+ * line is inserted before the header. If an error occurred <early_hints> is
+ * released and NULL is returned. On success the updated buffer is returned.
+ */
+static struct buffer *htx_apply_early_hint_rule(struct stream* s, struct buffer *early_hints,
+                                               const char* name, unsigned int name_len,
+                                               struct list *fmt)
+{
+       if (!early_hints) {
+               early_hints = alloc_trash_chunk();
+               if (!early_hints)
+                       goto fail;
+               if (!chunk_memcat(early_hints, HTTP_103.ptr, HTTP_103.len))
+                       goto fail;
+       }
+
+       if (!chunk_memcat(early_hints, name, name_len) || !chunk_memcat(early_hints, ": ", 2))
+               goto fail;
+
+       early_hints->data += build_logline(s, b_tail(early_hints), b_room(early_hints), fmt);
+       if (!chunk_memcat(early_hints, "\r\n", 2))
+               goto fail;
+
+       return early_hints;
+
+  fail:
+       free_trash_chunk(early_hints);
+       return NULL;
+}
+
+/* Sends an HTTP 103 response. Before sending it, the last CRLF finishing the
+ * response is added. If an error occurred or if another response was already
+ * sent, this function does nothing.
+ */
+static void htx_send_early_hints(struct stream *s, struct buffer *early_hints)
+{
+       struct channel *chn = s->txn->rsp.chn;
+       struct htx *htx;
+
+       /* If a response was already sent, skip early hints */
+       if (s->txn->status > 0)
+               return;
+
+       if (!chunk_memcat(early_hints, "\r\n", 2))
+               return;
+
+       htx = htx_from_buf(&chn->buf);
+       if (!htx_add_oob(htx, ist2(early_hints->area, early_hints->data)))
+               return;
+
+       c_adv(chn, early_hints->data);
+       chn->total += early_hints->data;
+}
+
 /* This function executes one of the set-{method,path,query,uri} actions. It
  * takes the string from the variable 'replace' with length 'len', then modifies
  * the relevant part of the request line accordingly. Then it updates various