From 960b2036a97baded1b61b405e4fa99380f807ff9 Mon Sep 17 00:00:00 2001
From: Sergio Correia <scorreia@redhat.com>
Date: Mon, 12 Feb 2024 13:07:45 +0000
Subject: [PATCH 2/2] Fix issue introduced in http-parser -> llhttp conversion

http_parser_execute() returns the number of parsed bytes, while
llhttp_execute() returns an error code.

Signed-off-by: Sergio Correia <scorreia@redhat.com>
---
 src/http.h  |  6 ++----
 src/tangd.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/src/http.h b/src/http.h
index 2e35686..8d9de51 100644
--- a/src/http.h
+++ b/src/http.h
@@ -30,10 +30,9 @@ typedef llhttp_status_t http_status_t;
 typedef llhttp_settings_t http_settings_t;
 typedef llhttp_t http_parser_t;
 #define tang_http_parser_init(parser, settings) llhttp_init(parser, HTTP_REQUEST, settings)
-#define tang_http_parser_execute(parser, settings, req, rcvd) llhttp_execute(parser, req, rcvd)
 #define tang_http_parser_errno(parser) parser.error
 #define tang_http_errno_description(parser, errno) llhttp_get_error_reason(parser)
-
+#define tang_http_parser_resume(parser) llhttp_resume(parser)
 #else
 /* Legacy http-parser. */
 #include <http_parser.h>
@@ -44,10 +43,9 @@ typedef http_parser_settings http_settings_t;
 typedef struct http_parser http_parser_t;
 
 #define tang_http_parser_init(parser, settings) http_parser_init(parser, HTTP_REQUEST)
-#define tang_http_parser_execute(parser, settings, req, rcvd) http_parser_execute(parser, settings, req, rcvd)
 #define tang_http_parser_errno(parser) parser.http_errno
 #define tang_http_errno_description(parser, errno) http_errno_description(errno)
-
+#define tang_http_parser_resume(parser) http_parser_pause(parser, 0)
 #endif /* USE_LLHTTP */
 
 struct http_dispatch {
diff --git a/src/tangd.c b/src/tangd.c
index 7f197f6..ab7f0cf 100644
--- a/src/tangd.c
+++ b/src/tangd.c
@@ -193,6 +193,44 @@ static struct http_dispatch dispatch[] = {
 
 #define DEFAULT_PORT 9090
 
+static size_t
+tang_http_parser_execute(http_parser_t *parser, const char* data, size_t len)
+{
+#ifdef USE_LLHTTP
+    llhttp_errno_t error;
+    size_t parsed_len;
+
+    /*
+     * Unlike http_parser, which returns the number of parsed
+     * bytes in the _execute() call, llhttp returns an error
+     * code.
+     */
+
+    if (data == NULL || len == 0) {
+        error = llhttp_finish(parser);
+    } else {
+        error = llhttp_execute(parser, data, len);
+    }
+
+    parsed_len = len;
+    /*
+     * Adjust number of parsed bytes in case of error.
+     */
+    if (error != HPE_OK) {
+        parsed_len = llhttp_get_error_pos(parser) - data;
+
+        /* This isn't a real pause, just a way to stop parsing early. */
+        if (error == HPE_PAUSED_UPGRADE) {
+            llhttp_resume_after_upgrade(parser);
+        }
+    }
+
+    return parsed_len;
+#else
+    return http_parser_execute(parser, &http_settings, data, len);
+#endif
+}
+
 static int
 process_request(const char *jwkdir, int in_fileno)
 {
@@ -225,8 +263,14 @@ process_request(const char *jwkdir, int in_fileno)
 
         rcvd += r;
 
-        r = tang_http_parser_execute(&parser, &http_settings, req, rcvd);
-        if (tang_http_parser_errno(parser) != 0) {
+        r = tang_http_parser_execute(&parser, req, rcvd);
+        switch (tang_http_parser_errno(parser)) {
+        case HPE_OK:
+            break;
+        case HPE_PAUSED:
+            tang_http_parser_resume(&parser);
+            break;
+        default:
             fprintf(stderr, "HTTP Parsing Error: %s\n",
                     tang_http_errno_description(&parser, tang_http_parser_errno(parser)));
             return EXIT_SUCCESS;
-- 
2.43.0