path: root/IkiWiki/CGI.pm

#!/usr/bin/perl

package IkiWiki;

use warnings;
use strict;
use IkiWiki;
use IkiWiki::UserInfo;
use open qw{:utf8 :std};
use Encode;

sub printheader ($) {
    my $session=shift;
    
    if ($ENV{HTTPS} || $config{sslcookie}) {
        print $session->header(-charset => 'utf-8',
            -cookie => $session->cookie(-httponly => 1, -secure => 1));
    }
    else {
        print $session->header(-charset => 'utf-8',
            -cookie => $session->cookie(-httponly => 1));
    }
}

sub prepform {
    my $form=shift;
    my $buttons=shift;
    my $session=shift;
    my $cgi=shift;

    if (exists $hooks{formbuilder}) {
        run_hooks(formbuilder => sub {
            shift->(form => $form, cgi => $cgi, session => $session,
                buttons => $buttons);
        });
    }

    return $form;
}

sub showform ($$$$;@) {
    my $form=prepform(@_);
    shift;
    my $buttons=shift;
    my $session=shift;
    my $cgi=shift;

    printheader($session);
    print misctemplate($form->title, $form->render(submit => $buttons), @_);
}

# Like showform, but the base url will be set to allow edit previews
# that use links relative to the specified page.
sub showform_preview ($$$$;@) {
    my $form=shift;
    my $buttons=shift;
    my $session=shift;
    my $cgi=shift;
    my %params=@_;

    # The base url needs to be a full URL, and urlto may return a path.
    my $baseurl = absurl(urlto($params{page}), $cgi->url);

    showform($form, $buttons, $session, $cgi, @_,
        forcebaseurl => $baseurl);
}

# Forces a partial url (path only) to absolute, using the same
# URL scheme as the CGI. Full URLs are left unchanged.
sub absurl ($$) {
    my $partialurl=shift;
    my $q=shift;

    eval q{use URI};
    return URI->new_abs($partialurl, $q->url);
}

sub redirect ($$) {
    my $q=shift;
    eval q{use URI};
    my $url=URI->new(absurl(shift, $q));
    if (! $config{w3mmode}) {
        print $q->redirect($url);
    }
    else {
        print "Content-type: text/plain\n";
        print "W3m-control: GOTO $url\n\n";
    }
}

sub decode_cgi_utf8 ($) {
    # decode_form_utf8 method is needed for 5.01
    if ($] < 5.01) {
        my $cgi = shift;
        foreach my $f ($cgi->param) {
            $cgi->param($f, map { decode_utf8 $_ } $cgi->param($f));
        }
    }
}

sub decode_form_utf8 ($) {
    if ($] >= 5.01) {
        my $form = shift;
        foreach my $f ($form->field) {
            my @value=map { decode_utf8($_) } $form->field($f);
            $form->field(name  => $f,
                         value => \@value,
                             force => 1,
            );
        }
    }
}

# Check if the user is signed in. If not, redirect to the signin form and
# save their place to return to later.
sub needsignin ($$) {
    my $q=shift;
    my $session=shift;

    if (! defined $session->param("name") ||
        ! userinfo_get($session->param("name"), "regdate")) {
        $session->param(postsignin => $ENV{QUERY_STRING});
        cgi_signin($q, $session);
        cgi_savesession($session);
        exit;
    }
}

sub cgi_signin ($$;$) {
    my $q=shift;
    my $session=shift;
    my $returnhtml=shift;

    decode_cgi_utf8($q);
    eval q{use CGI::FormBuilder};
    error($@) if $@;
    my $form = CGI::FormBuilder->new(
        title => "signin",
        name => "signin",
        charset => "utf-8",
        method => 'POST',
        required => 'NONE',
        javascript => 0,
        params => $q,
        action => cgiurl(),
        header => 0,
        template => {type => 'div'},
        stylesheet => 1,
    );
    my $buttons=["Login"];
    
    $form->field(name => "do", type => "hidden", value => "signin",
        force => 1);
    
    decode_form_utf8($form);
    run_hooks(formbuilder_setup => sub {
        shift->(form => $form, cgi => $q, session => $session,
                buttons => $buttons);
    });
    decode_form_utf8($form);

    if ($form->submitted) {
        $form->validate;
    }

    if ($returnhtml) {
        $form=prepform($form, $buttons, $session, $q);
        return $form->render(submit => $buttons);
    }

    showform($form, $buttons, $session, $q);
}

sub cgi_postsignin ($$) {
    my $q=shift;
    my $session=shift;
    
    # Continue with whatever was being done before the signin process.
    if (defined $session->param("postsignin")) {
        my $postsignin=CGI->new($session->param("postsignin"));
        $session->clear("postsignin");
        cgi($postsignin, $session);
        cgi_savesession($session);
        exit;
    }
    else {
        if ($config{sslcookie} && ! $q->https()) {
            error(gettext("probable misconfiguration: sslcookie is set, but you are attempting to login via http, not https"));
        }
        else {
            error(gettext("login failed, perhaps you need to turn on cookies?"));
        }
    }
}

sub cgi_prefs ($$) {
    my $q=shift;
    my $session=shift;

    needsignin($q, $session);
    decode_cgi_utf8($q);
    
    # The session id is stored on the form and checked to
    # guard against CSRF.
    my $sid=$q->param('sid');
    if (! defined $sid) {
        $q->delete_all;
    }
    elsif ($sid ne $session->id) {
        error(gettext("Your login session has expired."));
    }

    eval q{use CGI::FormBuilder};
    error($@) if $@;
    my $form = CGI::FormBuilder->new(
        title => "preferences",
        name => "preferences",
        header => 0,
        charset => "utf-8",
        method => 'POST',
        validate => {
            email => 'EMAIL',
        },
        required => 'NONE',
        javascript => 0,
        params => $q,
        action => cgiurl(),
        template => {type => 'div'},
        stylesheet => 1,
        fieldsets => [
            [login => gettext("Login")],
            [preferences => gettext("Preferences")],
            [admin => gettext("Admin")]
        ],
    );
    my $buttons=["Save Preferences", "Logout", "Cancel"];
    
    decode_form_utf8($form);
    run_hooks(formbuilder_setup => sub {
        shift->(form => $form, cgi => $q, session => $session,
                buttons => $buttons);
    });
    decode_form_utf8($form);
    
    $form->field(name => "do", type => "hidden", value => "prefs",
        force => 1);
    $form->field(name => "sid", type => "hidden", value => $session->id,
        force => 1);
    $form->field(name => "email", size => 50, fieldset => "preferences");
    
    my $user_name=$session->param("name");

    if (! $form->submitted) {
        $form->field(name => "email", force => 1,
            value => userinfo_get($user_name, "email"));
    }
    
    if ($form->submitted eq 'Logout') {
        $session->delete();
        redirect($q, baseurl(undef));
        return;
    }
    elsif ($form->submitted eq 'Cancel') {
        redirect($q, baseurl(undef));
        return;
    }
    elsif ($form->submitted eq 'Save Preferences' && $form->validate) {
        if (defined $form->field('email')) {
            userinfo_set($user_name, 'email', $form->field('email')) ||
                error("failed to set email");
        }

        $form->text(gettext("Preferences saved."));
    }
    
    showform($form, $buttons, $session, $q,
        prefsurl => "", # avoid showing the preferences link
    );
}

sub cgi_custom_failure ($$$) {
    my $q=shift;
    my $httpstatus=shift;
    my $message=shift;

    print $q->header(
        -status => $httpstatus,
        -charset => 'utf-8',
    );
    print $message;

    # Internet Explod^Hrer won't show custom 404 responses
    # unless they're >= 512 bytes
    print ' ' x 512;

    exit;
}

sub check_banned ($$) {
    my $q=shift;
    my $session=shift;

    my $banned=0;
    my $name=$session->param("name");
    if (defined $name && 
        grep { $name eq $_ } @{$config{banned_users}}) {
        $banned=1;
    }

    foreach my $b (@{$config{banned_users}}) {
        if (pagespec_match("", $b,
            ip => $session->remote_addr(),
            name => defined $name ? $name : "",
        )) {
            $banned=1;
            last;
        }
    }

    if ($banned) {
        $session->delete();
        cgi_savesession($session);
        cgi_custom_failure(
            $q, "403 Forbidden",
            gettext("You are banned."));
    }
}

sub cgi_getsession ($) {
    my $q=shift;

    eval q{use CGI::Session; use HTML::Entities};
    error($@) if $@;
    CGI::Session->name("ikiwiki_session_".encode_entities($config{wikiname}));
    
    my $oldmask=umask(077);
    my $session = eval {
        CGI::Session->new("driver:DB_File", $q,
            { FileName => "$config{wikistatedir}/sessions.db" })
    };
    if (! $session || $@) {
        error($@." ".CGI::Session->errstr());
    }
    
    umask($oldmask);

    return $session;
}

# To guard against CSRF, the user's session id (sid)
# can be stored on a form. This function will check
# (for logged in users) that the sid on the form matches
# the session id in the cookie.
sub checksessionexpiry ($$) {
    my $q=shift;
    my $session = shift;

    if (defined $session->param("name")) {
        my $sid=$q->param('sid');
        if (! defined $sid || $sid ne $session->id) {
            error(gettext("Your login session has expired."));
        }
    }
}

sub cgi_savesession ($) {
    my $session=shift;

    # Force session flush with safe umask.
    my $oldmask=umask(077);
    $session->flush;
    umask($oldmask);
}

sub cgi (;$$) {
    my $q=shift;
    my $session=shift;

    eval q{use CGI};
    error($@) if $@;
    $CGI::DISABLE_UPLOADS=$config{cgi_disable_uploads};

    if (! $q) {
        binmode(STDIN);
        $q=CGI->new;
        binmode(STDIN, ":utf8");
    
        run_hooks(cgi => sub { shift->($q) });
    }

    my $do=$q->param('do');
    if (! defined $do || ! length $do) {
        my $error = $q->cgi_error;
        if ($error) {
            error("Request not processed: $error");
        }
        else {
            error("\"do\" parameter missing");
        }
    }

    # Need to lock the wiki before getting a session.
    lockwiki();
    loadindex();
    
    if (! $session) {
        $session=cgi_getsession($q);
    }
    
    # Auth hooks can sign a user in.
    if ($do ne 'signin' && ! defined $session->param("name")) {
        run_hooks(auth => sub {
            shift->($q, $session)
        });
        if (defined $session->param("name")) {
            # Make sure whatever user was authed is in the
            # userinfo db.
            if (! userinfo_get($session->param("name"), "regdate")) {
                userinfo_setall($session->param("name"), {
                    email => "",
                    password => "",
                    regdate => time,
                }) || error("failed adding user");
            }
        }
    }
    
    check_banned($q, $session);
    
    run_hooks(sessioncgi => sub { shift->($q, $session) });

    if ($do eq 'signin') {
        cgi_signin($q, $session);
        cgi_savesession($session);
    }
    elsif ($do eq 'prefs') {
        cgi_prefs($q, $session);
    }
    elsif (defined $session->param("postsignin") || $do eq 'postsignin') {
        cgi_postsignin($q, $session);
    }
    else {
        error("unknown do parameter");
    }
}

# Does not need to be called directly; all errors will go through here.
sub cgierror ($) {
    my $message=shift;

    print "Content-type: text/html\n\n";
    print misctemplate(gettext("Error"),
        "<p class=\"error\">".gettext("Error").": $message</p>");
    die $@;
}

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