Add support for date header

common/socket_helper.h

@@ -9,6 +9,7 @@
 #define HEADER_CONTENT_LENGTH "Content-Length"
 #define HEADER_TRANSFER_ENCODING "Transfer-Encoding"
 #define HEADER_CONNECTION "Connection"
+#define HEADER_DATE "Date"
 
 enum line_type {RESULT_START_LINE, RESULT_HEADER, RESULT_BLANK_LINE, RESULT_NO_LINE};
 enum socket_result {RESULT_OK, RESULT_MALFORMED, RESULT_READ_ERROR, RESULT_PROCESSING_ERROR, RESULT_WRITE_ERROR};

server/socket_server.c

@@ -11,6 +11,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/socket.h>
+#include <time.h>
 #include <unistd.h>
 
 /**
@@ -80,6 +81,21 @@ struct server_info setup(int port) {
     return info;
 }
 
+/**
+ * Make an HTTP date for the date header
+ *
+ * @param buffer The buffer to write into
+ * @param buffer_size The max size of the buffer
+ *
+ * @return The number of bytes the format takes up, excluding the null term.
+ */
+static size_t make_http_date(char *buffer, size_t buffer_size) {
+    time_t current_time = time(NULL);
+    struct tm *utc_time = gmtime(&current_time);
+
+    return strftime(buffer, buffer_size, DATE_FORMAT, utc_time);
+}
+
 /**
  * Sends the headers and status line of the response
  *
@@ -121,8 +137,15 @@ static int send_headers(int status_code, int client_socket, long content_length)
         free(content_length_string);
     }
 
+    // The 1024 is somewhat arbitrary, but everything should fit.
+    char *date_header_buffer = malloc(1024 * sizeof(char));
+    header_buffer_size += make_http_date(date_header_buffer, 1024);
+    // +4 is ': \r\n'
+    header_buffer_size += strlen(HEADER_DATE) + 4;
+
     char *header_buffer = malloc(header_buffer_size * sizeof(char));
-    sprintf(header_buffer, "%s: close\r\n%s\r\n", HEADER_CONNECTION, content_length_header_buffer);
+    sprintf(header_buffer, "%s: close\r\n%s: %s\r\n%s\r\n", HEADER_CONNECTION, HEADER_DATE, date_header_buffer, content_length_header_buffer);
+    free(date_header_buffer);
     if (content_length > 0) {
         free(content_length_header_buffer);
     }

server/socket_server.h

@@ -6,6 +6,7 @@
 #define LISTEN_ADDR "::"
 #define BACKLOG_SIZE 8
 #define HTTP_VERSION "HTTP/1.1"
+#define DATE_FORMAT "%a, %d %b %Y %H:%M:%S %Z"
 #define FILE_BUFFER_SIZE 1024
 
 enum server_status {STATUS_LISTENING, STATUS_CLOSED, STATUS_ERROR};