Implement If-Modified-Since.

From Kyle Thompson <jmp AT giga DOT moe>.
Tweaks by me.
OK benno@

diff --git a/usr.sbin/httpd/server_file.c b/usr.sbin/httpd/server_file.c
index 2b75c57..52e50ff 100644 (file)
--- a/usr.sbin/httpd/server_file.c
+++ b/usr.sbin/httpd/server_file.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: server_file.c,v 1.53 2015/05/03 18:39:58 florian Exp $        */
+/*     $OpenBSD: server_file.c,v 1.54 2015/05/05 11:10:13 florian Exp $        */
 
 /*
  * Copyright (c) 2006 - 2015 Reyk Floeter <reyk@openbsd.org>
@@ -51,6 +51,8 @@ int            server_partial_file_request(struct httpd *, struct client *,
                    char *, struct stat *, char *);
 int             server_file_index(struct httpd *, struct client *,
                    struct stat *);
+int             server_file_modified_since(struct http_descriptor *,
+                   struct stat *);
 int             server_file_method(struct client *);
 int             parse_range_spec(char *, size_t, struct range *);
 struct range   *parse_range(char *, size_t, int *);
@@ -229,6 +231,9 @@ server_file_request(struct httpd *env, struct client *clt, char *path,
                goto abort;
        }
 
+       if ((ret = server_file_modified_since(clt->clt_descreq, st)) != -1)
+               return ret;
+
        /* Now open the file, should be readable or we have another problem */
        if ((fd = open(path, O_RDONLY)) == -1)
                goto abort;
@@ -627,6 +632,26 @@ server_file_error(struct bufferevent *bev, short error, void *arg)
        return;
 }
 
+int
+server_file_modified_since(struct http_descriptor * desc, struct stat * st)
+{
+       struct kv                key, *since;
+       struct tm                tm;
+
+       memset(&tm, 0, sizeof(struct tm));
+
+       key.kv_key = "If-Modified-Since";
+       if ((since = kv_find(&desc->http_headers, &key)) != NULL &&
+           since->kv_value != NULL) {
+               if (strptime(since->kv_value, "%a, %d %h %Y %T %Z", &tm) !=
+                   NULL && timegm(&tm) >= st->st_mtim.tv_sec) {
+                       return (304);
+               }
+       }
+
+       return (-1);
+}
+
 struct range *
 parse_range(char *str, size_t file_sz, int *nranges)
 {
@@ -734,4 +759,3 @@ buffer_add_range(int fd, struct evbuffer *evb, struct range *range)
 
        return (1);
 }
-