http: reject content-length duplicates with different values

src/http.c

@@ -41,8 +41,6 @@ void lx_http_handle_data(lx_connection_t *conn) {
     lx_close(conn);
     return;
   }
-
-  log_info("Received: %d bytes, buffer size: %ld, nread size: %ld", bytes, conn->size, req->parser.nread);
 
   lx_buf_t input = { .buf = conn->buf, .size = conn->size };
   int parser_code = lx_http_parser_exec(&req->parser, &input);

src/http_parser.c

@@ -43,6 +43,8 @@ const char *lx_http_map_code(lx_parser_status_t code) {
     return "Limit of max headers exceeded.";
   case LX_INVALID_CONTENT_LENGTH:
     return "Invalid content-length header value.";
+  case LX_CONTENT_LENGTH_DUPLICATE:
+    return "Received duplicated content-length header with different value.";
   default:
     return "Unknown HTTP parser code.";
   }
@@ -111,6 +113,7 @@ void lx_http_parser_init(lx_http_parser_t *parser) {
   parser->nread = 0;
   parser->nheaders = 0;
   parser->content_length = 0;
+  parser->content_length_received = 0;
 
   parser->header_key.start = NULL;
   parser->header_key.size = 0;
@@ -125,6 +128,13 @@ void lx_http_parser_init(lx_http_parser_t *parser) {
   parser->method.size = 0;
 }
 
+enum lx_http_connection_header {
+  LX_KEEP_ALIVE,
+  LX_UPGRADE,
+  LX_CLOSE,
+  LX_INVALID
+};
+
 // TODO: it would be more performant to detect specific headers during processing
 int lx_on_header_complete(lx_http_parser_t *parser) {
   http_raw_header_t *header = parser->req->raw_headers + parser->nheaders;
@@ -139,7 +149,13 @@ int lx_on_header_complete(lx_http_parser_t *parser) {
         if (result == -1) {
           return LX_INVALID_CONTENT_LENGTH;
         }
+
+        if (parser->content_length_received && parser->content_length != result) {
+          return LX_CONTENT_LENGTH_DUPLICATE;
+        }
+
         parser->content_length = result;
+        parser->content_length_received = 1;
       }
       break;
     default:

src/http_parser.h

@@ -12,7 +12,8 @@ typedef enum lx_parser_status {
   LX_INVALID_HEADER_KEY_CHAR,
   LX_INVALID_HEADER_VALUE_CHAR,
   LX_TOO_MANY_HEADERS,
-  LX_INVALID_CONTENT_LENGTH
+  LX_INVALID_CONTENT_LENGTH,
+  LX_CONTENT_LENGTH_DUPLICATE
 } lx_parser_status_t;
 
 typedef struct lx_buf {
@@ -63,6 +64,7 @@ typedef struct lx_http_parser {
   slice_t header_key;
   slice_t header_value;
   size_t content_length;
+  int content_length_received: 1;
   unsigned nheaders;
 } lx_http_parser_t;
 

src/http_request.h

@@ -54,6 +54,7 @@ typedef struct http_raw_header {
 struct http_request_s {
   char *path;
   http_method_t method;
+  int persistent: 1;
   char *body;
   size_t body_size;
   lx_http_parser_t parser;
@@ -71,6 +72,7 @@ static http_request_t *http_request_alloc() {
   req->connection = NULL;
   lx_http_parser_init(&req->parser);
   req->parser.req = req;
+  req->persistent = 1;
 
   return req;
 }