Added mode modularization

src/responseutil.c

@@ -0,0 +1,87 @@
+/*
+   swebs - a simple web server
+   Copyright (C) 2022  Nate Choe
+   
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <limits.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+#include <responseutil.h>
+
+#define CONST_FIELDS "Server: swebs/0.1\r\n"
+
+static int sendConnection(Connection *conn, char *format, ...) {
+	va_list ap;
+	va_start(ap, format);
+	int len = vsnprintf(NULL, 0, format, ap);
+	char *data = malloc(len + 1);
+	if (data == NULL)
+		return 1;
+
+	va_end(ap);
+	va_start(ap, format);
+
+	vsprintf(data, format, ap);
+	if (write(conn->fd, data, len) < len) {
+		free(data);
+		return 1;
+	}
+	free(data);
+	return 0;
+}
+
+int sendStringResponse(Connection *conn, char *status, char *str) {
+	return sendConnection(conn,
+		"HTTP/1.1 %s\r\n"
+		CONST_FIELDS
+		"Content-Length: %lu\r\n"
+		"\r\n"
+		"%s"
+		, status, strlen(str), str
+	);
+}
+
+int sendErrorResponse(Connection *conn, char *error) {
+	const char *template =
+		"<meta charset=utf-8>"
+		"<h1 text-align=center>"
+		  "%s"
+		"</h1>";
+	int len = snprintf(NULL, 0, template, error);
+	char *response = malloc(len + 1);
+	sprintf(response, template, error);
+	int ret = sendStringResponse(conn, error, response);
+	free(response);
+	return ret;
+}
+
+int sendBinaryResponse(Connection *conn, char *status,
+		void *data, size_t len) {
+	if (sendConnection(conn,
+		"HTTP/1.1 %s\r\n"
+		CONST_FIELDS
+		"Content-Length: %lu\r\n"
+		"\r\n"
+		, status, len)
+	)
+		return 1;
+	return write(conn->fd, data, len) < len;
+}