basic attachment plugin, unfinished

Currently includes UI, and a few tests of the attachment, as well as the
framework to extend pagespecs to test attachments. Does not actually save
the file yet.

diff --git a/IkiWiki/Plugin/attachment.pm b/IkiWiki/Plugin/attachment.pm
new file mode 100644 (file)
index 0000000..7af399f
--- /dev/null
+++ b/IkiWiki/Plugin/attachment.pm
@@ -0,0 +1,134 @@
+#!/usr/bin/perl
+package IkiWiki::Plugin::attachment;
+
+use warnings;
+use strict;
+use IkiWiki 2.00;
+use CGI;
+$CGI::DISABLE_UPLOADS=0;
+       
+# TODO move to admin prefs
+$config{valid_attachments}="(*.mp3 and maxsize(15mb)) or (* and maxsize(.50kb))";
+
+sub import { #{{{
+       hook(type => "formbuilder_setup", id => "attachment", call => \&formbuilder_setup);
+       hook(type => "formbuilder", id => "attachment", call => \&formbuilder);
+} # }}}
+
+sub formbuilder_setup { #{{{
+       my %params=@_;
+       my $form=$params{form};
+
+       return if $form->field("do") ne "edit";
+
+       $form->field(name => 'attachment', type => 'file');
+} #}}}
+
+sub formbuilder (@) { #{{{
+       my %params=@_;
+       my $form=$params{form};
+
+       return if $form->field("do") ne "edit";
+
+       if ($form->submitted eq "Upload") {
+               my $q=$params{cgi};
+               my $filename=IkiWiki::basename($q->param('attachment'));
+               if (! defined $filename || ! length $filename) {
+                       # no file, so do nothing
+                       return;
+               }
+               
+               # This is an (apparently undocumented) way to get the name
+               # of the temp file that CGI writes the upload to.
+               my $tempfile=$q->tmpFileName($filename);
+               
+               # To untaint the filename, escape any hazardous characters,
+               # and make sure it isn't pruned.
+               $filename=IkiWiki::possibly_foolish_untaint(IkiWiki::titlepage($filename));
+               if (IkiWiki::file_pruned($filename, $config{srcdir})) {
+                       error(gettext("bad attachment filename"));
+               }
+
+               # Check that the attachment matches the configured
+               # pagespec.
+               my $result=pagespec_match($filename, $config{valid_attachments},
+                       tempfile => $tempfile);
+               if (! $result) {
+                       error(gettext("attachment rejected")." ($result)");
+               }
+               
+               my $fh=$q->upload('attachment');
+               if (! defined $fh || ! ref $fh) {
+                       error("failed to get filehandle");
+               }
+               binmode($fh);
+               while (<$fh>) {
+                       print STDERR $_."\n";
+               }
+       }
+} # }}}
+
+package IkiWiki::PageSpec;
+
+sub parsesize { #{{{
+       my $size=shift;
+       no warnings;
+       my $base=$size+0; # force to number
+       use warnings;
+       my $exponent=1;
+       if ($size=~/kb?$/i) {
+               $exponent=10;
+       }
+       elsif ($size=~/mb?$/i) {
+               $exponent=20;
+       }
+       elsif ($size=~/gb?$/i) {
+               $exponent=30;
+       }
+       elsif ($size=~/tb?$/i) {
+               $exponent=40;
+       }
+       return $base * 2**$exponent;
+} #}}}
+
+sub match_maxsize ($$;@) { #{{{
+       shift;
+       my $maxsize=eval{parsesize(shift)};
+       if ($@) {
+               return IkiWiki::FailReason->new("unable to parse maxsize (or number too large)");
+       }
+
+       my %params=@_;
+       if (! exists $params{tempfile}) {
+               return IkiWiki::FailReason->new("no tempfile specified");
+       }
+
+       if (-s $params{tempfile} > $maxsize) {
+               return IkiWiki::FailReason->new("attachment too large");
+       }
+       else {
+               return IkiWiki::SuccessReason->new("attachment size ok");
+       }
+} #}}}
+
+sub match_minsize ($$;@) { #{{{
+       shift;
+       my $minsize=eval{parsesize(shift)};
+       if ($@) {
+               return IkiWiki::FailReason->new("unable to parse minsize (or number too large)");
+       }
+
+       my %params=@_;
+       if (! exists $params{tempfile}) {
+               return IkiWiki::FailReason->new("no tempfile specified");
+       }
+
+       if (-s $params{tempfile} < $minsize) {
+               return IkiWiki::FailReason->new("attachment too small");
+       }
+       else {
+               return IkiWiki::SuccessReason->new("attachment size ok");
+       }
+} #}}}
+
+1

diff --git a/doc/plugins/attachment.mdwn b/doc/plugins/attachment.mdwn
new file mode 100644 (file)
index 0000000..a038659
--- /dev/null
+++ b/doc/plugins/attachment.mdwn
@@ -0,0 +1,43 @@
+[[template id=plugin name=conditional core=1 author="[[Joey]]"]]
+[[tag type/useful]]
+
+This plugin allows files to be uploaded to the wiki over the web.
+
+For each page `foo`, files in the subdirectory `foo/` are treated as
+attachments of that page. Attachments can be uploaded and managed as
+part of the interface for editing a page.
+
+Warning: Do not enable this plugin on publically editable wikis, unless you
+take care to lock down the types and sizes of files that can be uploaded.
+Bear in mind that if you let anyone upload a particular kind of file
+("*.mp3" files, say), then someone can abuse your wiki in at least three ways:
+
+1. By uploading many mp3 files, wasting your disk space.
+2. By uploading mp3 files that attempt to exploit security holes
+   in web browsers or other players.
+3. By uploading files that claim to be mp3 files, but are really some 
+   other kind of file. Some web browsers may display a `foo.mp3` that
+   contains html as a web page; including running any malicious javascript
+   embedded in that page.
+
+To provide a way to combat these abuses, the wiki admin can specify a
+[[ikiwiki/PageSpec]] on their preferences page, to control what types of
+attachments can be uploaded. The regular [[ikiwiki/PageSpec]] syntax is
+expanded with additional tests.
+
+For example, to limit arbitrary files to 50 kilobtes, but allow
+larger mp3 files to be uploaded, a test like this could be used:
+  
+       (*.mp3 and maxsize(15mb)) or (* and maxsize(50kb))
+
+The following additional tests are available:
+
+* maxsize(size)
+
+  Tests whether the attachment is no larger than the specified size.
+  The size defaults to being in bytes, but "kb", "mb", "gb" etc can be
+  used to specify the units.
+  
+* minsize(size)
+
+  Tests whether the attachment is no smaller than the specified size.