*/ - </script> - <body> - This is where the header <i>should</i> be inserted. - <script> - /* this looks like the closing tag for the title:

From 96e026c1815f123e5a60ee106cb802fc841faa6c Mon Sep 17 00:00:00 2001 From: root Date: Thu, 29 Apr 2021 00:02:41 +0000 Subject: Fix filter-related bug Apparently, an Apache filter can be invoked more than once for a single request, depending on the size of the contents [1]. Luckily, though, a filter can save state in the ctx field [1,2]. The solution isn't perfect, as it can't handle arbitrary long heads, but they're very unlikely. [1] https://httpd.apache.org/docs/2.4/developer/output-filters.html#invocation [2] https://perl.apache.org/docs/2.0/user/handlers/filters.html#Introducing_Filters --- README | 55 ++++++++++++++++++++++++++++++------------------------- 1 file changed, 30 insertions(+), 25 deletions(-) (limited to 'README') diff --git a/README b/README index ebbea98..f8fe202 100644 --- a/README +++ b/README @@ -116,31 +116,36 @@ OPERATION and forwards their combined contents. CAVEATS - Apache::Inject::Filter uses a regular expression to determine the proper - location of the injected header. It supports all valid HTML. However, it - does not parse embedded CSS and JavaScript, which means that it is - *possible* to construct an example where it will fail: - - */ - /* this looks like an opening tag for a new element: */ - </script> - <body> - This is where the header <i>should</i> be inserted. - <script> - /* this looks like the closing tag for the title: - This is where the header is actually inserted. - */ - - - - This specific type of document, however, is *incredibly* unlikely. In - this case, an ad-hoc solution is simpler, more efficient and more - maintainable than a general one. - - On FreeBSD, you may need to enable the accf_http kernel module in order - for the tests to work. Note that Apache::Inject works fine without the - module; it is only the tests that require it. + * Apache::Inject::Filter uses a regular expression to determine the + proper location of the injected header. It supports all valid HTML. + However, it does not parse embedded CSS and JavaScript, which means + that it is *possible* to construct an example where it will fail: + + */ + /* this looks like an opening tag for a new element: */ + </script> + <body> + This is where the header <i>should</i> be inserted. + <script> + /* this looks like the closing tag for the title: + This is where the header is actually inserted. + */ + + + + This specific type of document, however, is *incredibly* unlikely. + In this case, an ad-hoc solution is simpler, more efficient and more + maintainable than a general one. + + * Because of how Apache filters work, Inject may fail to find the end + of the if the is very long (in my experience over 7000 + characters). If this happens, it will decline the request, and the + contents will be served as though Inject had not been enabled. + + * On FreeBSD, you may need to enable the accf_http kernel module in + order for the tests to work. Note that Apache::Inject works fine + without the module; it is only the tests that require it. DIAGNOSTICS Apache::Inject and Apache::Inject::Filter log all errors and warnings to -- cgit v1.2.3