ikiwiki/IkiWiki/Plugin/img.pm

323 lines
8.5 KiB
Perl

#!/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]+)$/is) {
$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)
my $im = Image::Magick->new();
my $r = $im->Ping(file => $in);
if ($r) {
$format = lc $r;
}
else {
error sprintf(gettext("failed to determine format of %s"), $file);
}
}
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 $r;
if ($config{deterministic}) {
$im->Set('date:create' => 0);
$im->Set('date:modify' => 0);
$im->Set('option' => 'png:exclude-chunk=time');
}
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 $imgtag='<img src="'.$imgurl.'"';
$imgtag.=' width="'.$dwidth.'"' if defined $dwidth;
$imgtag.=' height="'.$dheight.'"' if defined $dheight;
$imgtag.= $attrs.
(exists $params{align} && ! exists $params{caption} ? ' align="'.$params{align}.'"' : '').
' />';
my $link;
if (! defined $params{link}) {
$link=$fileurl;
}
elsif ($params{link} =~ /^\w+:\/\//) {
$link=$params{link};
}
if (defined $link) {
$imgtag='<a href="'.$link.'">'.$imgtag.'</a>';
}
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 '<table class="img'.
(exists $params{align} ? " align-$params{align}" : "").
'">'.
'<caption>'.$params{caption}.'</caption>'.
'<tr><td>'.$imgtag.'</td></tr>'.
'</table>';
}
else {
return $imgtag;
}
}
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