hsts: add read/write callbacks

- read/write callback options
- man pages for the 4 new setopts
- test 1915 verifies the callbacks

Closes #5896

tests/data/Makefile.inc

@@ -204,7 +204,7 @@ test1700 test1701 test1702 \
 test1800 test1801 \
 \
                                     test1904 test1905 test1906 test1907 \
-test1908 test1909 test1910 test1911 test1912 test1913 test1914 \
+test1908 test1909 test1910 test1911 test1912 test1913 test1914 test1915 \
 \
 test2000 test2001 test2002 test2003 test2004 test2005 test2006 test2007 \
 test2008 test2009 test2010 test2011 test2012 test2013 test2014 test2015 \

tests/data/test1915

@@ -0,0 +1,50 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HSTS
+CURLOPT_HSTSREADFUNCTION
+</keywords>
+</info>
+
+# Server-side
+<reply>
+</reply>
+
+# Client-side
+<client>
+<features>
+HSTS
+http
+</features>
+<server>
+none
+</server>
+
+# require debug so that alt-svc can work over plain old HTTP
+<name>
+HSTS read/write callbacks
+</name>
+<tool>
+lib1915
+</tool>
+
+<command>
+http://%HOSTIP:%NOLISTENPORT/not-there/1915
+</command>
+</client>
+
+# Verify data after the test has been "shot"
+<verify>
+# it fails because there's nothing on that port
+<errorcode>
+7
+</errorcode>
+<stdout>
+[0/4] 1.example.com 20300320 01:02:03
+[1/4] 2.example.com 20300320 01:02:03
+[2/4] 3.example.com 20300320 01:02:03
+[3/4] 4.example.com 20300320 01:02:03
+</stdout>
+</verify>
+</testcase>