MEDIUM: h2: replace the HTTP parser with a full parser

Now h2c_frt_make_resp_headers() makes use of the H1 parser instead of
using the HTTP txn. As a benefit, it saves a memory copy by being able
to parse and transcode directly from the h1 output channel to the h2
output buffer.

It was verified that stats and redirect are properly dealt with.

1 files changed, 21 insertions, 114 deletions

diff --git a/src/proto_h2.c b/src/proto_h2.c
index 5df9aaec8..2bead2b24 100644
--- a/src/proto_h2.c
+++ b/src/proto_h2.c
@@ -37,7 +37,6 @@
 #include <proto/channel.h>
 #include <proto/cli.h>
 #include <proto/frontend.h>
-#include <proto/hdr_idx.h>
 #include <proto/hpack-dec.h>
 #include <proto/hpack-enc.h>
 #include <proto/hpack-hdr.h>
@@ -1020,34 +1019,24 @@ static int h2c_frt_handle_data(struct h2c *h2c, const char *payload, int plen)
 	return 1;
 }
 
-/* try to send a HEADERS frame matching HTTP/1 txn <h1> for stream id <sid>
- * over connection <h2c>, and using <outbuf> as a temporary buffer. Returns
- * 0 if not possible yet, <0 on error, >0 on success.
+/* Try to send a HEADERS frame matching HTTP/1 response present in the response
+ * channel <h1>, for stream id <sid> over connection <h2c>, and using <outbuf>
+ * as a temporary output buffer. Returns 0 if not possible yet, <0 on error, >0
+ * on success.
  */
-static int h2c_frt_make_resp_headers(struct h2c *h2c, int sid, const struct http_txn *h1, struct chunk *in, struct chunk *outbuf)
+static int h2c_frt_make_resp_headers(struct h2c *h2c, int sid, struct channel *h1, struct chunk *outbuf)
 {
 	struct appctx *appctx = h2c->appctx;
 	struct stream_interface *si = appctx->owner;
 	struct channel *res = si_ic(si);
-	char *eol, *sol, *col, *sov, *eov;
-	struct ist name, value;
-	int cur_idx;
 	int ret = -1;
+	int skip = 0;
+	unsigned int err_pos = 0;
+	enum ht_state err_state = 0;
 
 	if (h2c_mux_busy(h2c))
 		goto end;
 
-	/* check against incomplete H1 responses (should not happen) */
-	if (h1->rsp.msg_state < HTTP_MSG_BODY)
-		goto end;
-
-	/* try to read response headers */
-	chunk_reset(in);
-	if ((in->len = bo_getblk(h1->rsp.chn, in->str, h1->rsp.chn->buf->o, 0)) <= 0)
-		goto end;
-
-	sol = in->str;
-
 	if ((res->buf == &buf_empty) &&
 	    !channel_alloc_buffer(res, &appctx->buffer_wait)) {
 		si_applet_cant_put(si);
@@ -1059,91 +1048,16 @@ static int h2c_frt_make_resp_headers(struct h2c *h2c, int sid, const struct http
 	/* len: 0x000000 (fill later), type: 1(HEADERS), flags: ENDS+ENDH=5 */
 	memcpy(outbuf->str, "\x00\x00\x00\x01\x05", 5);
 	h2_u32_encode(outbuf->str + 5, sid); // 4 bytes
+	outbuf->len = 9;
 
-	/* frame payload starts at str + 9 */
-	outbuf->str[9]  = 0x48; //   indexed name: idx8=":status"
-	outbuf->str[10] = 0x03; //   3 bytes status
-
-	/* we're taking the status from the HTTP/1.1 TXN, hoping it's always
-	 * valid. We also have the status code present as pure text at position
-	 * (sol + h1->rsp.sl.st.c) for (h1->rsp.sl.st.c_l) bytes, but only if
-	 * the response was not produced by haproxy (it was parsed) so better
-	 * rely on the status.
-	 */
-	outbuf->str[11] = '0' + (h1->status / 100) % 10;
-	outbuf->str[12] = '0' + (h1->status / 10) % 10;
-	outbuf->str[13] = '0' + (h1->status / 1) % 10;
-	outbuf->len = 14;
-
-	/* regular headers start to be dumped at outbuf->str + len. We iterate
-	 * over all of them and drop the connection-specific ones. For now they
-	 * are all sent as pure literals.
-	 */
-
-	sol += hdr_idx_first_pos(&h1->hdr_idx);
-	cur_idx = hdr_idx_first_idx(&h1->hdr_idx);
-
-	while (cur_idx) {
-		eol = sol + h1->hdr_idx.v[cur_idx].len;
-		col = sol;
-		while (col < eol && *col != ':')
-			col++;
-
-		sov = col + 1;
-		while (sov < eol && HTTP_IS_LWS(*sov))
-			sov++;
-
-		eov = eol;
-		while (eov - 1 > sov && HTTP_IS_LWS(*(eov - 1)))
-			eov--;
-
-		/* we have the header name between sol and col (excluded), and
-		 * its value between sov and eov (excluded).
-		 */
-		name  = (sol < col) ? ist2(sol, col - sol) : ist("");
-		value = (sov < eov) ? ist2(sov, eov - sov) : ist("");
-
-		/* the name must be lower-case */
-		for (sol = name.ptr; sol < name.ptr + name.len; sol++)
-			if (isupper((unsigned char)*sol))
-				*sol = tolower(*sol);
-
-		/* RFC7540 #8.1.2.2.  Connection-Specific Header Fields
-		 * An endpoint MUST NOT generate an HTTP/2 message containing
-		 * connection-specific header fields; ...
-		 * This means that an intermediary transforming an HTTP/1.x
-		 * message to HTTP/2 will need to remove any header fields
-		 * nominated by the Connection header field, along with the
-		 * Connection header field itself. Such intermediaries SHOULD
-		 * also remove other connection-specific header fields, such
-		 * as Keep-Alive, Proxy-Connection, Transfer-Encoding, and
-		 * Upgrade, even if they are not nominated by the Connection
-		 * header field.
-		 */
-		if (!isteq(name, ist("connection")) &&
-		    !isteq(name, ist("proxy-connection")) &&
-		    !isteq(name, ist("keep-alive")) &&
-		    !isteq(name, ist("upgrade")) &&
-		    !isteq(name, ist("transfer-encoding"))) {
-			outbuf->str[outbuf->len++] = 0x00;      /* literal without indexing -- new name */
-			outbuf->str[outbuf->len++] = name.len;  /* bogus, limited to 7 bits for now */
-			memcpy(outbuf->str + outbuf->len, name.ptr, name.len);
-			outbuf->len += name.len;
-			outbuf->str[outbuf->len++] = value.len;  /* bogus, limited to 7 bits for now */
-			memcpy(outbuf->str + outbuf->len, value.ptr, value.len);
-			outbuf->len += value.len;
-		}
-
-		sol = eol + h1->hdr_idx.v[cur_idx].cr + 1;
-		cur_idx = h1->hdr_idx.v[cur_idx].next;
+	skip = h1->buf->o;
+	ret = h1_headers_to_h2(bo_ptr(h1->buf), h1->buf->p,
+	                       outbuf, NULL, 0, &err_pos, &err_state);
+	if (ret <= 0) { // incomplete or error
+		ret--;
+		goto end;
 	}
-
-	/* skip optional CR and LF */
-	if (sol < in->str + in->len && *sol == '\r')
-		sol++;
-
-	if (sol < in->str + in->len && *sol == '\n')
-		sol++;
+	skip = ret;
 
 	/* update the frame's size */
 	h2_set_frame_size(outbuf->str, outbuf->len - 9);
@@ -1151,9 +1065,10 @@ static int h2c_frt_make_resp_headers(struct h2c *h2c, int sid, const struct http
 
 	/* consume incoming H1 response */
 	if (ret > 0)
-		bo_skip(h1->rsp.chn, sol - in->str);
+		bo_skip(h1, skip);
+
  end:
-	fprintf(stderr, "[%d] sent simple H2 response (sid=%d) = %d bytes (%d in)\n", appctx->st0, sid, ret, (int)(sol - in->str));
+	fprintf(stderr, "[%d] sent simple H2 response (sid=%d) = %d bytes (%d in, ep=%u, es=%s)\n", appctx->st0, sid, ret, skip, err_pos, http_msg_state_str(err_state));
 
 	/* success: >= 0 ; wait: -1; failure: < -1 */
 	return ret + 1;
@@ -1176,7 +1091,6 @@ static int h2c_frt_process_frames(struct h2c *h2c, struct h2s *only_h2s)
 	struct chunk *in = NULL;
 	struct h2s *h2s;
 	struct stream *h1s;
-	struct http_txn *h1;
 	int frame_len;
 	int ret;
 	int sid;
@@ -1193,15 +1107,8 @@ static int h2c_frt_process_frames(struct h2c *h2c, struct h2s *only_h2s)
 		h2s = LIST_ELEM(h2c->active_list.n, struct h2s *, list);
 		sid = h2s->id;
 		h1s = si_strm(h2s->appctx->owner);
-		h1 = h1s->txn;
-		if (!h1) {
-			fprintf(stderr, "Stream %p (id=%d h1s=%p) has a NULL TXN so is apparently closed. Deleting it from the active list.\n", h2s, sid, h1s);
-			LIST_DEL(h2c->active_list.n);
-			LIST_INIT(h2c->active_list.n);
-			continue;
-		}
-		fprintf(stderr, "trying to process response from stream %p (id=%d) h1s=%p h1txn=%p hdr_idx=%p\n", h2s, sid, h1s, h1, &h1->hdr_idx);
-		ret = h2c_frt_make_resp_headers(h2c, sid, h1, in, outbuf);
+		fprintf(stderr, "trying to process response from stream %p (id=%d) h1s=%p\n", h2s, sid, h1s);
+		ret = h2c_frt_make_resp_headers(h2c, sid, si_oc(h2s->appctx->owner), outbuf);
 
 		if (ret < 0) {
 			h2c_error(h2c, H2_ERR_PROTOCOL_ERROR);