BUG/MINOR: http: properly detect max-age=0 and s-maxage=0 in responses

In 1.3.8, commit a15645d ("[MAJOR] completed the HTTP response processing.")
improved the response parser by taking care of the cache-control header
field. The parser is wrong because it is split in two parts, one checking
for elements containing an equal sign and the other one for those without.
The "max-age=0" and "s-maxage=0" tests were located at the wrong place and
thus have never matched. In practice the side effect was very minimal given
that this code used to be enabled only when checking if a cookie had the
risk of being cached or not. Recently in 1.8 it was also used to decide if
the response could be cached but in practice the cache takes care of these
values by itself so there is very limited impact.

This fix can be backported to all stable versions.

diff --git a/src/proto_http.c b/src/proto_http.c
index 42e253aeb997d29bb0802d99c7c9ac06fd88dfd3..701ced43cf0c34f074fc3de0d3ef6d7efb8f7fd0 100644 (file)
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -7680,7 +7680,7 @@ void manage_server_side_cookies(struct stream *s, struct channel *res)
 
 
 /*
- * Check if response is cacheable or not. Updates s->flags.
+ * Check if response is cacheable or not. Updates s->txn->flags.
  */
 void check_response_for_cacheability(struct stream *s, struct channel *rtr)
 {
@@ -7712,8 +7712,7 @@ void check_response_for_cacheability(struct stream *s, struct channel *rtr)
                cur_next = cur_end + cur_hdr->cr + 1;
 
                /* We have one full header between cur_ptr and cur_end, and the
-                * next header starts at cur_next. We're only interested in
-                * "Cookie:" headers.
+                * next header starts at cur_next.
                 */
 
                val = http_header_match2(cur_ptr, cur_end, "Pragma", 6);
@@ -7744,6 +7743,12 @@ void check_response_for_cacheability(struct stream *s, struct channel *rtr)
 
                /* we have a complete value between p1 and p2 */
                if (p2 < cur_end && *p2 == '=') {
+                       if (((cur_end - p2) > 1 && (p2 - p1 == 7) && strncasecmp(p1, "max-age=0", 9) == 0) ||
+                           ((cur_end - p2) > 1 && (p2 - p1 == 8) && strncasecmp(p1, "s-maxage=0", 10) == 0)) {
+                               txn->flags &= ~TX_CACHEABLE & ~TX_CACHE_COOK;
+                               continue;
+                       }
+
                        /* we have something of the form no-cache="set-cookie" */
                        if ((cur_end - p1 >= 21) &&
                            strncasecmp(p1, "no-cache=\"set-cookie", 20) == 0
@@ -7755,9 +7760,7 @@ void check_response_for_cacheability(struct stream *s, struct channel *rtr)
                /* OK, so we know that either p2 points to the end of string or to a comma */
                if (((p2 - p1 ==  7) && strncasecmp(p1, "private", 7) == 0) ||
                    ((p2 - p1 ==  8) && strncasecmp(p1, "no-cache", 8) == 0) ||
-                   ((p2 - p1 ==  8) && strncasecmp(p1, "no-store", 8) == 0) ||
-                   ((p2 - p1 ==  9) && strncasecmp(p1, "max-age=0", 9) == 0) ||
-                   ((p2 - p1 == 10) && strncasecmp(p1, "s-maxage=0", 10) == 0)) {
+                   ((p2 - p1 ==  8) && strncasecmp(p1, "no-store", 8) == 0)) {
                        txn->flags &= ~TX_CACHEABLE & ~TX_CACHE_COOK;
                        return;
                }