{"id":404,"date":"2011-11-23T16:14:34","date_gmt":"2011-11-23T14:14:34","guid":{"rendered":"\/\/www.mcgill.org.za\/stuff\/?p=404"},"modified":"2011-11-23T16:14:34","modified_gmt":"2011-11-23T14:14:34","slug":"byteswap-in-socket-gethostname-or-something","status":"publish","type":"post","link":"https:\/\/www.mcgill.org.za\/stuff\/archives\/404","title":{"rendered":"Byteswap in socket.gethostname or something"},"content":{"rendered":"<p>Something weird and unresolved for today:<\/p>\n<p>So this automated process gets server host name, and sents it as part of a HTTP <strong>POST<\/strong> to another server.\u00a0 The data was encrypted with SSL in transmission.\u00a0 When it arrived, it was changed from:<br \/>\n<code>jrep<strong>ub<\/strong>lic.somedomain.com<\/code><br \/>\nto<br \/>\n<code>jrep<strong>bu<\/strong>lic.somedomain.com<\/code><\/p>\n<p>I ran it again manually, and it behaved normally, without the byteswap. Now, the way to generate this error, in software is something like this:<\/p>\n<blockquote><p><code>xchg al,ah<\/code><\/p><\/blockquote>\n<p>But there is nothing like that &#8230;<\/p>\n<p>The source system:<\/p>\n<ul>\n<li>CPU: Intel(R) Core(TM)2 Quad CPU Q8400 @ 2.66GHz<\/li>\n<li>Motherboard: Intel DG43GT<\/li>\n<li>Temperature: 40 degrees C<\/li>\n<li>Ethernet controller: 8086:10ce: Intel Corporation 82567V-2 Gigabit Network Connection<\/li>\n<li>Client: python 2.4.3<\/li>\n<\/ul>\n<p>The target system:<\/p>\n<ul>\n<li>CPU: Intel(R) Core(TM)2 CPU 4400\u00a0 @ 2.00GHz<\/li>\n<li>Motherboard: Intel DG33BU<\/li>\n<li>Ethernet controller:\u00a08086:294c: Intel Corporation Gigabit Ethernet Controller (rev 02)<\/li>\n<li>Temperature: 42 degrees C<\/li>\n<li>Server: python 2.4.3<\/li>\n<\/ul>\n<p>The traffic traversed the following systems:<\/p>\n<ul>\n<li>4 Cisco switches<\/li>\n<li>Fortigate firewall (two of these)<\/li>\n<li>Cisco backbone stuff<\/li>\n<li>Possibly 1 Netgear switch<\/li>\n<\/ul>\n<p>I suspect a CPU error on the originating server, since it is <em>likely<\/em> that SSL would stop if there was an error &#8230;\u00a0 but really don&#8217;t know.\u00a0 A byteswap on the network that just happened to pass the checksumming in SSL is not beyond belief. Oh well.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Something weird and unresolved for today: So this automated process gets server host name, and sents it as part of a HTTP POST to another server.\u00a0 The data was encrypted with SSL in transmission.\u00a0 When it arrived, it was changed &hellip; <a href=\"https:\/\/www.mcgill.org.za\/stuff\/archives\/404\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[43,44,45,190],"class_list":["post-404","post","type-post","status-publish","format-standard","hentry","category-stuff","tag-huh","tag-python","tag-ssl","tag-stuff"],"_links":{"self":[{"href":"https:\/\/www.mcgill.org.za\/stuff\/wp-json\/wp\/v2\/posts\/404","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mcgill.org.za\/stuff\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mcgill.org.za\/stuff\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mcgill.org.za\/stuff\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mcgill.org.za\/stuff\/wp-json\/wp\/v2\/comments?post=404"}],"version-history":[{"count":1,"href":"https:\/\/www.mcgill.org.za\/stuff\/wp-json\/wp\/v2\/posts\/404\/revisions"}],"predecessor-version":[{"id":405,"href":"https:\/\/www.mcgill.org.za\/stuff\/wp-json\/wp\/v2\/posts\/404\/revisions\/405"}],"wp:attachment":[{"href":"https:\/\/www.mcgill.org.za\/stuff\/wp-json\/wp\/v2\/media?parent=404"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mcgill.org.za\/stuff\/wp-json\/wp\/v2\/categories?post=404"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mcgill.org.za\/stuff\/wp-json\/wp\/v2\/tags?post=404"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}