MINOR: http: use http uri parser for authority

Replace http_get_authority by the http_uri_parser API.

The new function is renamed http_parse_authority. Replace duplicated
scheme parsing code by http_parse_scheme invocation. A new
http_uri_parser state is declared to mark the authority parsing as done.
diff --git a/include/haproxy/http-t.h b/include/haproxy/http-t.h
index ddc0f23..db0ce23 100644
--- a/include/haproxy/http-t.h
+++ b/include/haproxy/http-t.h
@@ -135,6 +135,7 @@
 enum http_uri_parser_state {
 	URI_PARSER_STATE_BEFORE = 0,
 	URI_PARSER_STATE_SCHEME_DONE,
+	URI_PARSER_STATE_AUTHORITY_DONE,
 };
 
 /* HTTP URI format as described in rfc 7230 5.3.
diff --git a/include/haproxy/http.h b/include/haproxy/http.h
index 60e101e..2b73649 100644
--- a/include/haproxy/http.h
+++ b/include/haproxy/http.h
@@ -37,7 +37,7 @@
 int http_get_status_idx(unsigned int status);
 const char *http_get_reason(unsigned int status);
 struct ist http_parse_scheme(struct http_uri_parser *parser);
-struct ist http_get_authority(const struct ist uri, int no_userinfo);
+struct ist http_parse_authority(struct http_uri_parser *parser, int no_userinfo);
 struct ist http_get_path(const struct ist uri);
 int http_header_match2(const char *hdr, const char *end,
                        const char *name, int len);
diff --git a/src/h1.c b/src/h1.c
index 3a6c1c3..4b13cab 100644
--- a/src/h1.c
+++ b/src/h1.c
@@ -871,8 +871,9 @@
 				else if (!(h1m->flags & (H1_MF_HDRS_ONLY|H1_MF_RESP)) && isteqi(n, ist("host"))) {
 					if (host_idx == -1) {
 						struct ist authority;
+						struct http_uri_parser parser = http_uri_parser_init(sl.rq.u);
 
-						authority = http_get_authority(sl.rq.u, 1);
+						authority = http_parse_authority(&parser, 1);
 						if (authority.len && !isteqi(v, authority)) {
 							if (h1m->err_pos < -1) {
 								state = H1_MSG_HDR_L2_LWS;
diff --git a/src/http.c b/src/http.c
index 2899232..8b3d20b 100644
--- a/src/http.c
+++ b/src/http.c
@@ -523,55 +523,40 @@
  * path. if no_userinfo is not zero, the part before the '@' (including it) is
  * skipped. If not found, an empty ist is returned. Otherwise, the ist pointing
  * on the authority is returned.
+ *
+ * <parser> must have been initialized via http_uri_parser_init. See the
+ * related http_uri_parser documentation for the specific API usage.
  */
-struct ist http_get_authority(const struct ist uri, int no_userinfo)
+struct ist http_parse_authority(struct http_uri_parser *parser, int no_userinfo)
 {
 	const char *ptr, *start, *end;
 
-	if (!uri.len)
+	if (parser->state >= URI_PARSER_STATE_AUTHORITY_DONE)
 		goto not_found;
 
-	ptr = uri.ptr;
-	start = ptr;
-	end = ptr + uri.len;
-
-	/* RFC7230, par. 2.7 :
-	 * Request-URI = "*" | absuri | abspath | authority
-	 */
-
-	if (*ptr == '*' || *ptr == '/')
+	if (parser->format != URI_PARSER_FORMAT_ABSURI_OR_AUTHORITY)
 		goto not_found;
 
-	if (isalpha((unsigned char)*ptr)) {
-		/* this is a scheme as described by RFC3986, par. 3.1, or only
-		 * an authority (in case of a CONNECT method).
-		 */
-		ptr++;
-		while (ptr < end &&
-		       (isalnum((unsigned char)*ptr) || *ptr == '+' || *ptr == '-' || *ptr == '.'))
-			ptr++;
-		/* skip '://' or take the whole as authority if not found */
-		if (ptr == end || *ptr++ != ':')
-			goto authority;
-		if (ptr == end || *ptr++ != '/')
-			goto authority;
-		if (ptr == end || *ptr++ != '/')
-			goto authority;
-	}
+	if (parser->state < URI_PARSER_STATE_SCHEME_DONE)
+		http_parse_scheme(parser);
 
-	start = ptr;
+	ptr = start = istptr(parser->uri);
+	end = istend(parser->uri);
+
 	while (ptr < end && *ptr != '/') {
 		if (*ptr++ == '@' && no_userinfo)
 			start = ptr;
 	}
 
 	/* OK, ptr point on the '/' or the end */
-	end = ptr;
 
   authority:
-	return ist2(start, end - start);
+	parser->uri = ist2(ptr, end - ptr);
+	parser->state = URI_PARSER_STATE_AUTHORITY_DONE;
+	return ist2(start, ptr - start);
 
   not_found:
+	parser->state = URI_PARSER_STATE_AUTHORITY_DONE;
 	return IST_NULL;
 }
 
diff --git a/src/http_htx.c b/src/http_htx.c
index 5a62d0a..2e39191 100644
--- a/src/http_htx.c
+++ b/src/http_htx.c
@@ -691,9 +691,11 @@
 {
 	struct buffer *temp = get_trash_chunk();
 	struct ist meth, vsn, uri, authority;
+	struct http_uri_parser parser;
 
 	uri = htx_sl_req_uri(sl);
-	authority = http_get_authority(uri, 1);
+	parser = http_uri_parser_init(uri);
+	authority = http_parse_authority(&parser, 1);
 	if (!authority.len)
 		return 0;
 
@@ -728,9 +730,11 @@
 {
 	struct ist authority;
 	struct http_hdr_ctx ctx;
+	struct http_uri_parser parser = http_uri_parser_init(uri);
 
-	if (!uri.len || uri.ptr[0] == '/' ||  uri.ptr[0] == '*') {
-		// origin-form or a asterisk-form (RFC7320 #5.3.1 and #5.3.4)
+	if (parser.format == URI_PARSER_FORMAT_EMPTY ||
+	    parser.format == URI_PARSER_FORMAT_ASTERISK ||
+	    parser.format == URI_PARSER_FORMAT_ABSPATH) {
 		sl->flags &= ~HTX_SL_F_HAS_AUTHORITY;
 	}
 	else {
@@ -741,7 +745,7 @@
 			if (uri.len > 4 && (uri.ptr[0] | 0x20) == 'h')
 				sl->flags |= ((uri.ptr[4] == ':') ? HTX_SL_F_SCHM_HTTP : HTX_SL_F_SCHM_HTTPS);
 
-			authority = http_get_authority(uri, 1);
+			authority = http_parse_authority(&parser, 1);
 			if (!authority.len)
 				goto fail;
 		}
@@ -1759,7 +1763,7 @@
 	 * hostnames, do a reverse search on the last ':' separator as long as
 	 * digits are found.
 	 */
-	authority = http_get_authority(uri, 0);
+	authority = http_parse_authority(&parser, 0);
 	start = istptr(authority);
 	end = istend(authority);
 	for (ptr = end; ptr > start && isdigit((unsigned char)*--ptr); )