#!/usr/bin/perl # Ikiwiki enhanced image handling plugin # Christian Mock cm@tahina.priv.at 20061002 package IkiWiki::Plugin::img; use warnings; use strict; use IkiWiki 3.00; my %imgdefaults; sub import { hook(type => "getsetup", id => "img", call => \&getsetup); hook(type => "preprocess", id => "img", call => \&preprocess, scan => 1); } sub getsetup () { return plugin => { safe => 1, rebuild => undef, section => "widget", }, img_allowed_formats => { type => "string", default => [qw(jpeg png gif svg)], description => "Image formats to process (jpeg, png, gif, svg, pdf or 'everything' to accept all)", # ImageMagick has had arbitrary code execution flaws, # and the whole delegates mechanism is scary from # that perspective safe => 0, rebuild => 0, }, } sub allowed { my $format = shift; my $allowed = $config{img_allowed_formats}; $allowed = ['jpeg', 'png', 'gif', 'svg'] unless defined $allowed && @$allowed; foreach my $a (@$allowed) { return 1 if lc($a) eq $format || lc($a) eq 'everything'; } return 0; } sub preprocess (@) { my ($image) = $_[0] =~ /$config{wiki_file_regexp}/; # untaint my %params=@_; if (! defined $image) { error("bad image filename"); } if (exists $imgdefaults{$params{page}}) { foreach my $key (keys %{$imgdefaults{$params{page}}}) { if (! exists $params{$key}) { $params{$key}=$imgdefaults{$params{page}}->{$key}; } } } if (! exists $params{size} || ! length $params{size}) { $params{size}='full'; } if ($image eq 'defaults') { $imgdefaults{$params{page}} = \%params; return ''; } add_link($params{page}, $image); add_depends($params{page}, $image); # optimisation: detect scan mode, and avoid generating the image if (! defined wantarray) { return; } my $file = bestlink($params{page}, $image); my $srcfile = srcfile($file, 1); if (! length $file || ! defined $srcfile) { return htmllink($params{page}, $params{destpage}, $image); } my $dir = $params{page}; my $base = IkiWiki::basename($file); my $extension; my $format; if ($base =~ m/\.([a-z0-9]+)$/) { $extension = $1; } else { error gettext("Unable to detect image type from extension"); } # Never interpret well-known file extensions as any other format, # in case the wiki configuration unwisely allows attaching # arbitrary files named *.jpg, etc. my $magic; my $offset = 0; open(my $in, '<', $srcfile) or error sprintf(gettext("failed to read %s: %s"), $file, $!); binmode($in); if ($extension =~ m/^(jpeg|jpg)$/is) { $format = 'jpeg'; $magic = "\377\330\377"; } elsif ($extension =~ m/^(png)$/is) { $format = 'png'; $magic = "\211PNG\r\n\032\n"; } elsif ($extension =~ m/^(gif)$/is) { $format = 'gif'; $magic = "GIF8"; } elsif ($extension =~ m/^(svg)$/is) { $format = 'svg'; } elsif ($extension =~ m/^(pdf)$/is) { $format = 'pdf'; $magic = "%PDF-"; } else { # allow ImageMagick to auto-detect (potentially dangerous) $format = ''; } error sprintf(gettext("%s image processing disabled in img_allowed_formats configuration"), $format ? $format : "\"$extension\"") unless allowed($format ? $format : "everything"); # Try harder to protect ImageMagick from itself if (defined $magic) { my $content; read($in, $content, length $magic) or error sprintf(gettext("failed to read %s: %s"), $file, $!); if ($magic ne $content) { error sprintf(gettext("\"%s\" does not seem to be a valid %s file"), $file, $format); } } my $ispdf = $base=~s/\.pdf$/.png/i; my $pagenumber = exists($params{pagenumber}) ? int($params{pagenumber}) : 0; if ($pagenumber != 0) { $base = "p$pagenumber-$base"; } my $imglink; my $imgdatalink; my ($dwidth, $dheight); my ($w, $h); if ($params{size} ne 'full') { ($w, $h) = ($params{size} =~ /^(\d*)x(\d*)$/); } if ($format eq 'svg') { # svg images are not scaled using ImageMagick because the # pipeline is complex. Instead, the image size is simply # set to the provided values. # # Aspect ratio will be preserved automatically when # only a width or only a height is specified. # When both are specified, aspect ratio will not be # preserved. $imglink = $file; $dwidth = $w if length $w; $dheight = $h if length $h; } else { eval q{use Image::Magick}; error gettext("Image::Magick is not installed") if $@; my $im = Image::Magick->new(); my $r = $im->Read("$format:$srcfile\[$pagenumber]"); error sprintf(gettext("failed to read %s: %s"), $file, $r) if $r; if (! defined $im->Get("width") || ! defined $im->Get("height")) { error sprintf(gettext("failed to get dimensions of %s"), $file); } if (! length $w && ! length $h) { $dwidth = $im->Get("width"); $dheight = $im->Get("height"); } else { error sprintf(gettext('wrong size format "%s" (should be WxH)'), $params{size}) unless (defined $w && defined $h && (length $w || length $h)); if ($im->Get("width") == 0 || $im->Get("height") == 0) { ($dwidth, $dheight)=(0, 0); } elsif (! length $w || (length $h && $im->Get("height")*$w > $h * $im->Get("width"))) { # using height because only height is given or ... # because original image is more portrait than $w/$h # ... slimness of $im > $h/w # ... $im->Get("height")/$im->Get("width") > $h/$w # ... $im->Get("height")*$w > $h * $im->Get("width") $dheight=$h; $dwidth=$h / $im->Get("height") * $im->Get("width"); } else { # (! length $h) or $w is what determines the resized size $dwidth=$w; $dheight=$w / $im->Get("width") * $im->Get("height"); } } if ($dwidth < $im->Get("width") || $ispdf) { # resize down, or resize to pixels at all my $outfile = "$config{destdir}/$dir/$params{size}-$base"; $imglink = "$dir/$params{size}-$base"; will_render($params{page}, $imglink); if (-e $outfile && (-M $srcfile >= -M $outfile)) { $im = Image::Magick->new; $r = $im->Read($outfile); error sprintf(gettext("failed to read %s: %s"), $outfile, $r) if $r; } else { $r = $im->Resize(geometry => "${dwidth}x${dheight}"); error sprintf(gettext("failed to resize: %s"), $r) if $r; $im->set($ispdf ? (magick => 'png') : ()); my @blob = $im->ImageToBlob(); # don't actually write resized file in preview mode; # rely on width and height settings if (! $params{preview}) { writefile($imglink, $config{destdir}, $blob[0], 1); } else { eval q{use MIME::Base64}; error($@) if $@; $imgdatalink = "data:image/".$im->Get("magick").";base64,".encode_base64($blob[0]); } } # always get the true size of the resized image (it could be # that imagemagick did its calculations differently) $dwidth = $im->Get("width"); $dheight = $im->Get("height"); } else { $imglink = $file; } if (! defined($dwidth) || ! defined($dheight)) { error sprintf(gettext("failed to determine size of image %s"), $file) } } my ($fileurl, $imgurl); my $urltobase = $params{preview} ? undef : $params{destpage}; $fileurl=urlto($file, $urltobase); $imgurl=$imgdatalink ? $imgdatalink : urlto($imglink, $urltobase); if (! exists $params{class}) { $params{class}="img"; } my $attrs=''; foreach my $attr (qw{alt title class id hspace vspace}) { if (exists $params{$attr}) { $attrs.=" $attr=\"$params{$attr}\""; } } my $imgtag=''; my $link; if (! defined $params{link}) { $link=$fileurl; } elsif ($params{link} =~ /^\w+:\/\//) { $link=$params{link}; } if (defined $link) { $imgtag=''.$imgtag.''; } else { my $b = bestlink($params{page}, $params{link}); if (length $b) { add_depends($params{page}, $b, deptype("presence")); $imgtag=htmllink($params{page}, $params{destpage}, $params{link}, linktext => $imgtag, noimageinline => 1, ); } } if (exists $params{caption}) { return ''. ''. ''. '
'.$params{caption}.'
'.$imgtag.'
'; } else { return $imgtag; } } 1