X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/5d26ded3811cd050a1c70ccf76f3022a787a9588..fafca9860b3d88fe2b6d0bc413e8843d77123255:/IkiWiki/CGI.pm

diff --git a/IkiWiki/CGI.pm b/IkiWiki/CGI.pm
index 52d3474f5..2c5b4a84d 100644
--- a/IkiWiki/CGI.pm
+++ b/IkiWiki/CGI.pm
@@ -1,5 +1,7 @@
 #!/usr/bin/perl
 
+package IkiWiki;
+
 use warnings;
 use strict;
 use IkiWiki;
@@ -7,21 +9,20 @@ use IkiWiki::UserInfo;
 use open qw{:utf8 :std};
 use Encode;
 
-package IkiWiki;
-
-sub printheader ($) { #{{{
+sub printheader ($) {
 	my $session=shift;
 	
-	if ($config{sslcookie}) {
+	if (($ENV{HTTPS} && lc $ENV{HTTPS} ne "off") || $config{sslcookie}) {
 		print $session->header(-charset => 'utf-8',
-			-cookie => $session->cookie(-secure => 1));
-	} else {
-		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 showform ($$$$;@) { #{{{
+sub prepform {
 	my $form=shift;
 	my $buttons=shift;
 	my $session=shift;
@@ -34,13 +35,68 @@ sub showform ($$$$;@) { #{{{
 		});
 	}
 
+	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 => $buttons), @_);
+	print cgitemplate($cgi, $form->title,
+		$form->render(submit => $buttons), @_);
 }
 
-sub redirect ($$) { #{{{
+sub cgitemplate ($$$;@) {
+	my $cgi=shift;
+	my $title=shift;
+	my $content=shift;
+	my %params=@_;
+	
+	my $template=template("page.tmpl");
+
+	my $page="";
+	if (exists $params{page}) {
+		$page=delete $params{page};
+		$params{forcebaseurl}=urlto($page);
+	}
+	run_hooks(pagetemplate => sub {
+		shift->(
+			page => $page,
+			destpage => $page,
+			template => $template,
+		);
+	});
+	templateactions($template, "");
+
+	my $baseurl = baseurl();
+
+	$template->param(
+		dynamic => 1,
+		title => $title,
+		wikiname => $config{wikiname},
+		content => $content,
+		baseurl => $baseurl,
+		html5 => $config{html5},
+		%params,
+	);
+	
+	return $template->output;
+}
+
+sub redirect ($$) {
 	my $q=shift;
-	my $url=shift;
+	eval q{use URI};
+
+	my $topurl = $config{cgiurl};
+	if (defined $q && ! $config{w3mmode} && ! $config{reverse_proxy}) {
+		$topurl = $q->url;
+	}
+
+	my $url=URI->new(urlabs(shift, $topurl));
 	if (! $config{w3mmode}) {
 		print $q->redirect($url);
 	}
@@ -48,75 +104,61 @@ sub redirect ($$) { #{{{
 		print "Content-type: text/plain\n";
 		print "W3m-control: GOTO $url\n\n";
 	}
-} #}}}
-
-sub check_canedit ($$$;$) { #{{{
-	my $page=shift;
-	my $q=shift;
-	my $session=shift;
-	my $nonfatal=shift;
-	
-	my $canedit;
-	run_hooks(canedit => sub {
-		return if defined $canedit;
-		my $ret=shift->($page, $q, $session);
-		if (defined $ret) {
-			if ($ret eq "") {
-				$canedit=1;
-			}
-			elsif (ref $ret eq 'CODE') {
-				$ret->() unless $nonfatal;
-				$canedit=0;
-			}
-			elsif (defined $ret) {
-				error($ret) unless $nonfatal;
-				$canedit=0;
-			}
-		}
-	});
-	return $canedit;
-} #}}}
+}
 
-sub decode_cgi_utf8 ($) { #{{{
-	# decode_form_utf8 method is needed for 5.10
+sub decode_cgi_utf8 ($) {
+	# 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));
+			$cgi->param($f, map { decode_utf8 $_ }
+				@{$cgi->param_fetch($f)});
 		}
 	}
-} #}}}
+}
+
+sub safe_decode_utf8 ($) {
+    my $octets = shift;
+    if (!Encode::is_utf8($octets)) {
+        return decode_utf8($octets);
+    }
+    else {
+        return $octets;
+    }
+}
 
-sub decode_form_utf8 ($) { #{{{
+sub decode_form_utf8 ($) {
 	if ($] >= 5.01) {
 		my $form = shift;
 		foreach my $f ($form->field) {
+			my @value=map { safe_decode_utf8($_) } $form->field($f);
 			$form->field(name  => $f,
-			             value => decode_utf8($form->field($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 ($$) { #{{{
+sub needsignin ($$) {
 	my $q=shift;
 	my $session=shift;
 
-	if (! defined $session->param("name") ||
+	if (! length $session->param("name") ||
 	    ! userinfo_get($session->param("name"), "regdate")) {
-		$session->param(postsignin => $ENV{QUERY_STRING});
+		$session->param(postsignin => $q->query_string);
 		cgi_signin($q, $session);
 		cgi_savesession($session);
 		exit;
 	}
-} #}}}	
+}
 
-sub cgi_signin ($$) { #{{{
+sub cgi_signin ($$;$) {
 	my $q=shift;
 	my $session=shift;
+	my $returnhtml=shift;
 
 	decode_cgi_utf8($q);
 	eval q{use CGI::FormBuilder};
@@ -129,16 +171,13 @@ sub cgi_signin ($$) { #{{{
 		required => 'NONE',
 		javascript => 0,
 		params => $q,
-		action => $config{cgiurl},
+		action => cgiurl(),
 		header => 0,
 		template => {type => 'div'},
-		stylesheet => baseurl()."style.css",
+		stylesheet => 1,
 	);
 	my $buttons=["Login"];
 	
-	if ($q->param("do") ne "signin" && !$form->submitted) {
-		$form->text(gettext("You need to log in first."));
-	}
 	$form->field(name => "do", type => "hidden", value => "signin",
 		force => 1);
 	
@@ -153,10 +192,15 @@ sub cgi_signin ($$) { #{{{
 		$form->validate;
 	}
 
+	if ($returnhtml) {
+		$form=prepform($form, $buttons, $session, $q);
+		return $form->render(submit => $buttons);
+	}
+
 	showform($form, $buttons, $session, $q);
-} #}}}
+}
 
-sub cgi_postsignin ($$) { #{{{
+sub cgi_postsignin ($$) {
 	my $q=shift;
 	my $session=shift;
 	
@@ -169,11 +213,16 @@ sub cgi_postsignin ($$) { #{{{
 		exit;
 	}
 	else {
-		error(gettext("login failed, perhaps you need to turn on cookies?"));
+		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 succeeded, but I don't remember why you were logging in, so you'll have to navigate back to whatever you were doing. (This should not normally happen. Perhaps you need to enable cookies?)"));
+		}
 	}
-} #}}}
+}
 
-sub cgi_prefs ($$) { #{{{
+sub cgi_prefs ($$) {
 	my $q=shift;
 	my $session=shift;
 
@@ -204,9 +253,9 @@ sub cgi_prefs ($$) { #{{{
 		required => 'NONE',
 		javascript => 0,
 		params => $q,
-		action => $config{cgiurl},
+		action => cgiurl(),
 		template => {type => 'div'},
-		stylesheet => baseurl()."style.css",
+		stylesheet => 1,
 		fieldsets => [
 			[login => gettext("Login")],
 			[preferences => gettext("Preferences")],
@@ -227,422 +276,95 @@ sub cgi_prefs ($$) { #{{{
 	$form->field(name => "sid", type => "hidden", value => $session->id,
 		force => 1);
 	$form->field(name => "email", size => 50, fieldset => "preferences");
-	$form->field(name => "banned_users", size => 50,
-		fieldset => "admin");
 	
 	my $user_name=$session->param("name");
-	if (! is_admin($user_name)) {
-		$form->field(name => "banned_users", type => "hidden");
-	}
 
 	if (! $form->submitted) {
 		$form->field(name => "email", force => 1,
 			value => userinfo_get($user_name, "email"));
-		if (is_admin($user_name)) {
-			$form->field(name => "banned_users", force => 1,
-				value => join(" ", get_banned_users()));
-		}
 	}
 	
 	if ($form->submitted eq 'Logout') {
 		$session->delete();
-		redirect($q, $config{url});
+		redirect($q, baseurl(undef));
 		return;
 	}
 	elsif ($form->submitted eq 'Cancel') {
-		redirect($q, $config{url});
+		redirect($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')) ||
+		my $email = $form->field('email');
+		if (defined $email) {
+			userinfo_set($user_name, 'email', $email) ||
 				error("failed to set email");
 		}
-		if (is_admin($user_name)) {
-			set_banned_users(grep { ! is_admin($_) }
-					split(' ',
-						$form->field("banned_users"))) ||
-				error("failed saving changes");
-		}
+
 		$form->text(gettext("Preferences saved."));
 	}
 	
-	showform($form, $buttons, $session, $q);
-} #}}}
+	showform($form, $buttons, $session, $q,
+		prefsurl => "", # avoid showing the preferences link
+	);
+}
 
-sub cgi_editpage ($$) { #{{{
+sub cgi_custom_failure ($$$) {
 	my $q=shift;
-	my $session=shift;
-	
-	decode_cgi_utf8($q);
+	my $httpstatus=shift;
+	my $message=shift;
 
-	my @fields=qw(do rcsinfo subpage from page type editcontent comments);
-	my @buttons=("Save Page", "Preview", "Cancel");
-	eval q{use CGI::FormBuilder};
-	error($@) if $@;
-	my $form = CGI::FormBuilder->new(
-		fields => \@fields,
-		charset => "utf-8",
-		method => 'POST',
-		required => [qw{editcontent}],
-		javascript => 0,
-		params => $q,
-		action => $config{cgiurl},
-		header => 0,
-		table => 0,
-		template => scalar template_params("editpage.tmpl"),
-		wikiname => $config{wikiname},
+	print $q->header(
+		-status => $httpstatus,
+		-charset => 'utf-8',
 	);
-	
-	decode_form_utf8($form);
-	run_hooks(formbuilder_setup => sub {
-		shift->(form => $form, cgi => $q, session => $session,
-			buttons => \@buttons);
-	});
-	decode_form_utf8($form);
-	
-	# This untaint is safe because we check file_pruned.
-	my $page=$form->field('page');
-	$page=possibly_foolish_untaint($page);
-	if (! defined $page || ! length $page ||
-	    file_pruned($page, $config{srcdir}) || $page=~/^\//) {
-		error("bad page name");
-	}
+	print $message;
 
-	my $baseurl=$config{url}."/".htmlpage($page);
-	
-	my $from;
-	if (defined $form->field('from')) {
-		($from)=$form->field('from')=~/$config{wiki_file_regexp}/;
-	}
-	
-	my $file;
-	my $type;
-	if (exists $pagesources{$page} && $form->field("do") ne "create") {
-		$file=$pagesources{$page};
-		$type=pagetype($file);
-		if (! defined $type || $type=~/^_/) {
-			error(sprintf(gettext("%s is not an editable page"), $page));
-		}
-		if (! $form->submitted) {
-			$form->field(name => "rcsinfo",
-				value => rcs_prepedit($file), force => 1);
-		}
-		$form->field(name => "editcontent", validate => '/.*/');
-	}
-	else {
-		$type=$form->param('type');
-		if (defined $type && length $type && $hooks{htmlize}{$type}) {
-			$type=possibly_foolish_untaint($type);
-		}
-		elsif (defined $from && exists $pagesources{$from}) {
-			# favor the type of linking page
-			$type=pagetype($pagesources{$from});
-		}
-		$type=$config{default_pageext} unless defined $type;
-		$file=$page.".".$type;
-		if (! $form->submitted) {
-			$form->field(name => "rcsinfo", value => "", force => 1);
-		}
-		$form->field(name => "editcontent", validate => '/.+/');
-	}
-
-	$form->field(name => "do", type => 'hidden');
-	$form->field(name => "sid", type => "hidden", value => $session->id,
-		force => 1);
-	$form->field(name => "from", type => 'hidden');
-	$form->field(name => "rcsinfo", type => 'hidden');
-	$form->field(name => "subpage", type => 'hidden');
-	$form->field(name => "page", value => $page, force => 1);
-	$form->field(name => "type", value => $type, force => 1);
-	$form->field(name => "comments", type => "text", size => 80);
-	$form->field(name => "editcontent", type => "textarea", rows => 20,
-		cols => 80);
-	$form->tmpl_param("can_commit", $config{rcs});
-	$form->tmpl_param("indexlink", indexlink());
-	$form->tmpl_param("helponformattinglink",
-		htmllink($page, $page, "ikiwiki/formatting",
-			noimageinline => 1,
-			linktext => "FormattingHelp"));
-	
-	if ($form->submitted eq "Cancel") {
-		if ($form->field("do") eq "create" && defined $from) {
-			redirect($q, "$config{url}/".htmlpage($from));
-		}
-		elsif ($form->field("do") eq "create") {
-			redirect($q, $config{url});
-		}
-		else {
-			redirect($q, "$config{url}/".htmlpage($page));
-		}
-		return;
-	}
-	elsif ($form->submitted eq "Preview") {
-		my $new=not exists $pagesources{$page};
-		if ($new) {
-			# temporarily record its type
-			$pagesources{$page}=$page.".".$type;
-		}
-
-		my $content=$form->field('editcontent');
+	# Internet Explod^Hrer won't show custom 404 responses
+	# unless they're >= 512 bytes
+	print ' ' x 512;
 
-		run_hooks(editcontent => sub {
-			$content=shift->(
-				content => $content,
-				page => $page,
-				cgi => $q,
-				session => $session,
-			);
-		});
-		my $preview=htmlize($page, $page, $type,
-			linkify($page, $page,
-			preprocess($page, $page,
-			filter($page, $page, $content), 0, 1)));
-		run_hooks(format => sub {
-			$preview=shift->(
-				page => $page,
-				content => $preview,
-			);
-		});
-		$form->tmpl_param("page_preview", $preview);
-	
-		if ($new) {
-			delete $pagesources{$page};
-		}
-		# previewing may have created files on disk
-		saveindex();
-	}
-	elsif ($form->submitted eq "Save Page") {
-		$form->tmpl_param("page_preview", "");
-	}
-	$form->tmpl_param("page_conflict", "");
-	
-	if ($form->submitted ne "Save Page" || ! $form->validate) {
-		if ($form->field("do") eq "create") {
-			my @page_locs;
-			my $best_loc;
-			if (! defined $from || ! length $from ||
-			    $from ne $form->field('from') ||
-			    file_pruned($from, $config{srcdir}) ||
-			    $from=~/^\// ||
-			    $form->submitted eq "Preview") {
-				@page_locs=$best_loc=$page;
-			}
-			else {
-				my $dir=$from."/";
-				$dir=~s![^/]+/+$!!;
-				
-				if ((defined $form->field('subpage') && length $form->field('subpage')) ||
-				    $page eq gettext('discussion')) {
-					$best_loc="$from/$page";
-				}
-				else {
-					$best_loc=$dir.$page;
-				}
-				
-				push @page_locs, $dir.$page;
-				push @page_locs, "$from/$page";
-				while (length $dir) {
-					$dir=~s![^/]+/+$!!;
-					push @page_locs, $dir.$page;
-				}
-			
-				push @page_locs, "$config{userdir}/$page"
-					if length $config{userdir};
-			}
+	exit;
+}
 
-			@page_locs = grep {
-				! exists $pagecase{lc $_}
-			} @page_locs;
-			if (! @page_locs) {
-				# hmm, someone else made the page in the
-				# meantime?
-				if ($form->submitted eq "Preview") {
-					# let them go ahead with the edit
-					# and resolve the conflict at save
-					# time
-					@page_locs=$page;
-				}
-				else {
-					redirect($q, "$config{url}/".htmlpage($page));
-					return;
-				}
-			}
+sub check_banned ($$) {
+	my $q=shift;
+	my $session=shift;
 
-			my @editable_locs = grep {
-				check_canedit($_, $q, $session, 1)
-			} @page_locs;
-			if (! @editable_locs) {
-				# let it throw an error this time
-				map { check_canedit($_, $q, $session) } @page_locs;
-			}
-			
-			my @page_types;
-			if (exists $hooks{htmlize}) {
-				@page_types=grep { !/^_/ }
-					keys %{$hooks{htmlize}};
-			}
-			
-			$form->tmpl_param("page_select", 1);
-			$form->field(name => "page", type => 'select',
-				options => [ map { [ $_, pagetitle($_, 1) ] } @editable_locs ],
-				value => $best_loc);
-			$form->field(name => "type", type => 'select',
-				options => \@page_types);
-			$form->title(sprintf(gettext("creating %s"), pagetitle($page)));
-			
+	my $banned=0;
+	my $name=$session->param("name");
+	my $cloak=cloak($name) if defined $name;
+	if (defined $name && 
+	    grep { $name eq $_ || $cloak eq $_ } @{$config{banned_users}}) {
+		$banned=1;
+	}
+
+	foreach my $b (@{$config{banned_users}}) {
+		if (pagespec_match("", $b,
+			ip => $session->remote_addr(),
+			name => defined $name ? $name : "")
+		   || pagespec_match("", $b,
+		   	ip => cloak($session->remote_addr()),
+			name => defined $cloak ? $cloak : "")) {
+			$banned=1;
+			last;
 		}
-		elsif ($form->field("do") eq "edit") {
-			check_canedit($page, $q, $session);
-			if (! defined $form->field('editcontent') || 
-			    ! length $form->field('editcontent')) {
-				my $content="";
-				if (exists $pagesources{$page}) {
-					$content=readfile(srcfile($pagesources{$page}));
-					$content=~s/\n/\r\n/g;
-				}
-				$form->field(name => "editcontent", value => $content,
-					force => 1);
-			}
-			$form->tmpl_param("page_select", 0);
-			$form->field(name => "page", type => 'hidden');
-			$form->field(name => "type", type => 'hidden');
-			$form->title(sprintf(gettext("editing %s"), pagetitle($page)));
-		}
-		
-		showform($form, \@buttons, $session, $q, forcebaseurl => $baseurl);
 	}
-	else {
-		# save page
-		check_canedit($page, $q, $session);
-	
-		# The session id is stored on the form and checked to
-		# guard against CSRF. But only if the user is logged in,
-		# as anonok can allow anonymous edits.
-		if (defined $session->param("name")) {
-			my $sid=$q->param('sid');
-			if (! defined $sid || $sid ne $session->id) {
-				error(gettext("Your login session has expired."));
-			}
-		}
-
-		my $exists=-e "$config{srcdir}/$file";
-
-		if ($form->field("do") ne "create" && ! $exists &&
-		    ! defined srcfile($file, 1)) {
-			$form->tmpl_param("page_gone", 1);
-			$form->field(name => "do", value => "create", force => 1);
-			$form->tmpl_param("page_select", 0);
-			$form->field(name => "page", type => 'hidden');
-			$form->field(name => "type", type => 'hidden');
-			$form->title(sprintf(gettext("editing %s"), $page));
-			showform($form, \@buttons, $session, $q, forcebaseurl => $baseurl);
-			return;
-		}
-		elsif ($form->field("do") eq "create" && $exists) {
-			$form->tmpl_param("creation_conflict", 1);
-			$form->field(name => "do", value => "edit", force => 1);
-			$form->tmpl_param("page_select", 0);
-			$form->field(name => "page", type => 'hidden');
-			$form->field(name => "type", type => 'hidden');
-			$form->title(sprintf(gettext("editing %s"), $page));
-			$form->field("editcontent", 
-				value => readfile("$config{srcdir}/$file").
-				         "\n\n\n".$form->field("editcontent"),
-				force => 1);
-			showform($form, \@buttons, $session, $q, forcebaseurl => $baseurl);
-			return;
-		}
-		
-		my $content=$form->field('editcontent');
-		run_hooks(editcontent => sub {
-			$content=shift->(
-				content => $content,
-				page => $page,
-				cgi => $q,
-				session => $session,
-			);
-		});
-		$content=~s/\r\n/\n/g;
-		$content=~s/\r/\n/g;
-		$content.="\n" if $content !~ /\n$/;
-
-		$config{cgi}=0; # avoid cgi error message
-		eval { writefile($file, $config{srcdir}, $content) };
-		$config{cgi}=1;
-		if ($@) {
-			$form->field(name => "rcsinfo", value => rcs_prepedit($file),
-				force => 1);
-			$form->tmpl_param("failed_save", 1);
-			$form->tmpl_param("error_message", $@);
-			$form->field("editcontent", value => $content, force => 1);
-			$form->tmpl_param("page_select", 0);
-			$form->field(name => "page", type => 'hidden');
-			$form->field(name => "type", type => 'hidden');
-			$form->title(sprintf(gettext("editing %s"), $page));
-			showform($form, \@buttons, $session, $q,
-				forcebaseurl => $baseurl);
-			return;
-		}
-		
-		my $conflict;
-		if ($config{rcs}) {
-			my $message="";
-			if (defined $form->field('comments') &&
-			    length $form->field('comments')) {
-				$message=$form->field('comments');
-			}
-			
-			if (! $exists) {
-				rcs_add($file);
-			}
 
-			# Prevent deadlock with post-commit hook by
-			# signaling to it that it should not try to
-			# do anything.
-			disable_commit_hook();
-			$conflict=rcs_commit($file, $message,
-				$form->field("rcsinfo"),
-				$session->param("name"), $ENV{REMOTE_ADDR});
-			enable_commit_hook();
-			rcs_update();
-		}
-		
-		# Refresh even if there was a conflict, since other changes
-		# may have been committed while the post-commit hook was
-		# disabled.
-		require IkiWiki::Render;
-		refresh();
-		saveindex();
-
-		if (defined $conflict) {
-			$form->field(name => "rcsinfo", value => rcs_prepedit($file),
-				force => 1);
-			$form->tmpl_param("page_conflict", 1);
-			$form->field("editcontent", value => $conflict, force => 1);
-			$form->field("do", "edit", force => 1);
-			$form->tmpl_param("page_select", 0);
-			$form->field(name => "page", type => 'hidden');
-			$form->field(name => "type", type => 'hidden');
-			$form->title(sprintf(gettext("editing %s"), $page));
-			showform($form, \@buttons, $session, $q,
-				forcebaseurl => $baseurl);
-			return;
-		}
-		else {
-			# The trailing question mark tries to avoid broken
-			# caches and get the most recent version of the page.
-			redirect($q, "$config{url}/".htmlpage($page)."?updated");
-		}
+	if ($banned) {
+		$session->delete();
+		cgi_savesession($session);
+		cgi_custom_failure(
+			$q, "403 Forbidden",
+			gettext("You are banned."));
 	}
-} #}}}
+}
 
-sub cgi_getsession ($) { #{{{
+sub cgi_getsession ($) {
 	my $q=shift;
 
-	eval q{use CGI::Session};
+	eval q{use CGI::Session; use HTML::Entities};
 	error($@) if $@;
-	CGI::Session->name("ikiwiki_session_".encode_utf8($config{wikiname}));
+	CGI::Session->name("ikiwiki_session_".encode_entities($config{wikiname}));
 	
 	my $oldmask=umask(077);
 	my $session = eval {
@@ -650,30 +372,49 @@ sub cgi_getsession ($) { #{{{
 			{ FileName => "$config{wikistatedir}/sessions.db" })
 	};
 	if (! $session || $@) {
-		error($@." ".CGI::Session->errstr());
+		my $error = $@;
+		error($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 || ! length $session->param("name")) {
+			error(gettext("Your login session has expired."));
+		}
+	}
+}
 
-sub cgi_savesession ($) { #{{{
+sub cgi_savesession ($) {
 	my $session=shift;
 
 	# Force session flush with safe umask.
 	my $oldmask=umask(077);
 	$session->flush;
 	umask($oldmask);
-} #}}}
+}
 
-sub cgi (;$$) { #{{{
+sub cgi (;$$) {
 	my $q=shift;
 	my $session=shift;
 
 	eval q{use CGI};
 	error($@) if $@;
+	no warnings "once";
 	$CGI::DISABLE_UPLOADS=$config{cgi_disable_uploads};
+	use warnings;
 
 	if (! $q) {
 		binmode(STDIN);
@@ -693,7 +434,7 @@ sub cgi (;$$) { #{{{
 			error("\"do\" parameter missing");
 		}
 	}
-	
+
 	# Need to lock the wiki before getting a session.
 	lockwiki();
 	loadindex();
@@ -703,16 +444,16 @@ sub cgi (;$$) { #{{{
 	}
 	
 	# Auth hooks can sign a user in.
-	if ($do ne 'signin' && ! defined $session->param("name")) {
+	if ($do ne 'signin' && ! length $session->param("name")) {
 		run_hooks(auth => sub {
 			shift->($q, $session)
 		});
-		if (defined $session->param("name")) {
+		if (length $session->param("name")) {
 			# Make sure whatever user was authed is in the
 			# userinfo db.
 			if (! userinfo_get($session->param("name"), "regdate")) {
 				userinfo_setall($session->param("name"), {
-					email => "",
+					email => defined $session->param("email") ? $session->param("email") : "",
 					password => "",
 					regdate => time,
 				}) || error("failed adding user");
@@ -720,14 +461,8 @@ sub cgi (;$$) { #{{{
 		}
 	}
 	
-	if (defined $session->param("name") &&
-	    userinfo_get($session->param("name"), "banned")) {
-		print $q->header(-status => "403 Forbidden");
-		$session->delete();
-		print gettext("You are banned.");
-		cgi_savesession($session);
-	}
-
+	check_banned($q, $session);
+	
 	run_hooks(sessioncgi => sub { shift->($q, $session) });
 
 	if ($do eq 'signin') {
@@ -737,15 +472,26 @@ sub cgi (;$$) { #{{{
 	elsif ($do eq 'prefs') {
 		cgi_prefs($q, $session);
 	}
-	elsif ($do eq 'create' || $do eq 'edit') {
-		cgi_editpage($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;
+
+	eval q{use HTML::Entities};
+	$message = encode_entities($message);
+
+	print "Content-type: text/html\n\n";
+	print cgitemplate(undef, gettext("Error"),
+		"<p class=\"error\">".gettext("Error").": $message</p>");
+
+	die $message;
+}
 
 1