MINOR: cache: Process the If-Modified-Since header in conditional requests
If a client sends a conditional request containing an If-Modified-Since
header (and no If-None-Match header), we try to compare the date with
the one stored in the cache entry (coming either from a Last-Modified
head, or a Date header, or corresponding to the first response's
reception time). If the request's date is earlier than the stored one,
we send a "304 Not Modified" response back. Otherwise, the stored is sent
(through a 200 OK response).
This resolves GitHub issue #821.
diff --git a/reg-tests/cache/if-modified-since.vtc b/reg-tests/cache/if-modified-since.vtc
new file mode 100644
index 0000000..af8cbf0
--- /dev/null
+++ b/reg-tests/cache/if-modified-since.vtc
@@ -0,0 +1,145 @@
+varnishtest "If-Modified-Since support"
+
+#REQUIRE_VERSION=2.3
+
+feature ignore_unknown_macro
+
+server s1 {
+ # Response containing a "Last-Modified" field
+ rxreq
+ expect req.url == "/last_modified"
+ txresp -nolen -hdr "Transfer-Encoding: chunked" \
+ -hdr "Last-Modified: Thu, 15 Oct 2020 22:23:24 GMT"
+ chunkedlen 15
+ chunkedlen 15
+ chunkedlen 15
+ chunkedlen 0
+
+ # Response containing a "Date" field
+ rxreq
+ expect req.url == "/date"
+ txresp -nolen -hdr "Transfer-Encoding: chunked" \
+ -hdr "Date: Thu, 22 Oct 2020 16:51:12 GMT"
+ chunkedlen 16
+ chunkedlen 16
+ chunkedlen 16
+ chunkedlen 0
+
+ # Response containing both a "Last-Modified" and a "Date" fields
+ # Should behave the same way as if the "Date" field was not here.
+ rxreq
+ expect req.url == "/last_modified_and_date"
+ txresp -nolen -hdr "Transfer-Encoding: chunked" \
+ -hdr "Last-Modified: Thu, 15 Oct 2020 14:24:38 GMT" \
+ -hdr "Date: Thu, 22 Oct 2020 16:51:12 GMT"
+ chunkedlen 17
+ chunkedlen 17
+ chunkedlen 17
+ chunkedlen 0
+} -start
+
+haproxy h1 -conf {
+ defaults
+ mode http
+ ${no-htx} option http-use-htx
+ timeout connect 1s
+ timeout client 1s
+ timeout server 1s
+
+ frontend fe
+ bind "fd@${fe}"
+ default_backend test
+
+ backend test
+ http-request cache-use my_cache
+ server www ${s1_addr}:${s1_port}
+ http-response cache-store my_cache
+
+ cache my_cache
+ total-max-size 3
+ max-age 20
+ max-object-size 3072
+} -start
+
+
+client c1 -connect ${h1_fe_sock} {
+ txreq -url "/last_modified"
+ rxresp
+ expect resp.status == 200
+ expect resp.bodylen == 45
+
+ txreq -url "/date"
+ rxresp
+ expect resp.status == 200
+ expect resp.bodylen == 48
+
+ txreq -url "/last_modified_and_date"
+ rxresp
+ expect resp.status == 200
+ expect resp.bodylen == 51
+
+
+ # Earlier date
+ # "Last-Modified" version
+ txreq -url "/last_modified" \
+ -hdr "If-Modified-Since: Thu, 15 Oct 2020 00:00:01 GMT"
+ rxresp
+ expect resp.status == 200
+ expect resp.bodylen == 45
+ # "Date" version
+ txreq -url "/date" \
+ -hdr "If-Modified-Since: Thu, 01 Oct 2020 00:00:01 GMT"
+ rxresp
+ expect resp.status == 200
+ expect resp.bodylen == 48
+ # "Last-Modified" and "Date" version
+ txreq -url "/last_modified_and_date" \
+ -hdr "If-Modified-Since: Thu, 15 Oct 2020 00:00:01 GMT"
+ rxresp
+ expect resp.status == 200
+ expect resp.bodylen == 51
+
+
+ # Same date
+ # "Last-Modified" version
+ txreq -url "/last_modified" \
+ -hdr "If-Modified-Since: Thu, 15 Oct 2020 22:23:24 GMT"
+ rxresp
+ expect resp.status == 304
+ expect resp.bodylen == 0
+ # "Date" version
+ txreq -url "/date" \
+ -hdr "If-Modified-Since: Thu, 22 Oct 2020 16:51:12 GMT"
+ rxresp
+ expect resp.status == 304
+ expect resp.bodylen == 0
+ # "Last-Modified" and "Date" version
+ txreq -url "/last_modified_and_date" \
+ -hdr "If-Modified-Since: Thu, 15 Oct 2020 16:51:12 GMT"
+ rxresp
+ expect resp.status == 304
+ expect resp.bodylen == 0
+
+
+ # Later date
+ # "Last-Modified" version
+ txreq -url "/last_modified" \
+ -hdr "If-Modified-Since: Thu, 22 Oct 2020 23:00:00 GMT"
+ rxresp
+ expect resp.status == 304
+ expect resp.bodylen == 0
+ # "Date" version
+ txreq -url "/date" \
+ -hdr "If-Modified-Since: Thu, 22 Oct 2020 23:00:00 GMT"
+ rxresp
+ expect resp.status == 304
+ expect resp.bodylen == 0
+ # "Last-Modified" and "Date" version
+ txreq -url "/last_modified_and_date" \
+ -hdr "If-Modified-Since: Thu, 22 Oct 2020 23:00:00 GMT"
+ rxresp
+ expect resp.status == 304
+ expect resp.bodylen == 0
+
+} -run
+