X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/282893be819eab14f3a2078f1741ec9c9ed363b1..94a53ad8123095113a91e2bfd553af722cab3c8a:/IkiWiki/CGI.pm?ds=sidebyside

diff --git a/IkiWiki/CGI.pm b/IkiWiki/CGI.pm
index 2483bf4d8..cb83319e6 100644
--- a/IkiWiki/CGI.pm
+++ b/IkiWiki/CGI.pm
@@ -1,559 +1,482 @@
 #!/usr/bin/perl
 
+package IkiWiki;
+
 use warnings;
 use strict;
 use IkiWiki;
 use IkiWiki::UserInfo;
+use open qw{:utf8 :std};
+use Encode;
 
-package IkiWiki;
-
-sub page_locked ($$;$) { #{{{
-	my $page=shift;
+sub printheader ($) {
 	my $session=shift;
-	my $nonfatal=shift;
 	
-	my $user=$session->param("name");
-	return if defined $user && is_admin($user);
-
-	foreach my $admin (@{$config{adminuser}}) {
-		my $locked_pages=userinfo_get($admin, "locked_pages");
-		if (globlist_match($page, userinfo_get($admin, "locked_pages"))) {
-			return 1 if $nonfatal;
-			error(htmllink("", $page, 1)." is locked by ".
-			      htmllink("", $admin, 1)." and cannot be edited.");
-		}
+	if (($ENV{HTTPS} && lc $ENV{HTTPS} ne "off") || $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));
+	}
+}
 
-	return 0;
-} #}}}
+sub prepform {
+	my $form=shift;
+	my $buttons=shift;
+	my $session=shift;
+	my $cgi=shift;
 
-sub cgi_recentchanges ($) { #{{{
-	my $q=shift;
+	if (exists $hooks{formbuilder}) {
+		run_hooks(formbuilder => sub {
+			shift->(form => $form, cgi => $cgi, session => $session,
+				buttons => $buttons);
+		});
+	}
+
+	return $form;
+}
+
+sub showform ($$$$;@) {
+	my $form=prepform(@_);
+	shift;
+	my $buttons=shift;
+	my $session=shift;
+	my $cgi=shift;
+
+	printheader($session);
+	print cgitemplate($cgi, $form->title,
+		$form->render(submit => $buttons), @_);
+}
+
+sub cgitemplate ($$$;@) {
+	my $cgi=shift;
+	my $title=shift;
+	my $content=shift;
+	my %params=@_;
 	
-	unlockwiki();
+	my $template=template("page.tmpl");
+
+	my $topurl = defined $cgi ? $cgi->url : $config{url};
+
+	my $page="";
+	if (exists $params{page}) {
+		$page=delete $params{page};
+		$params{forcebaseurl}=urlabs(urlto($page), $topurl);
+	}
+	run_hooks(pagetemplate => sub {
+		shift->(
+			page => $page,
+			destpage => $page,
+			template => $template,
+		);
+	});
+	templateactions($template, "");
 
-	my $template=HTML::Template->new(
-		filename => "$config{templatedir}/recentchanges.tmpl"
-	);
 	$template->param(
-		title => "RecentChanges",
-		indexlink => indexlink(),
+		dynamic => 1,
+		title => $title,
 		wikiname => $config{wikiname},
-		changelog => [rcs_recentchanges(100)],
-		styleurl => styleurl(),
-		baseurl => "$config{url}/",
+		content => $content,
+		baseurl => urlabs(baseurl(), $topurl),
+		html5 => $config{html5},
+		%params,
 	);
-	print $q->header, $template->output;
-} #}}}
+	
+	return $template->output;
+}
 
-sub cgi_signin ($$) { #{{{
+sub redirect ($$) {
+	my $q=shift;
+	eval q{use URI};
+	my $url=URI->new(urlabs(shift, $q->url));
+	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 safe_decode_utf8 ($) {
+    my $octets = shift;
+    # call decode_utf8 on >= 5.20 only if it's not already decoded,
+    # otherwise it balks, on < 5.20, always call it
+    if ($] < 5.02 || !Encode::is_utf8($octets)) {
+        return decode_utf8($octets);
+    }
+    else {
+        return $octets;
+    }
+}
+
+sub decode_form_utf8 ($) {
+	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 => \@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 ($$) {
+	my $q=shift;
+	my $session=shift;
+
+	if (! defined $session->param("name") ||
+	    ! userinfo_get($session->param("name"), "regdate")) {
+		$session->param(postsignin => $q->query_string);
+		cgi_signin($q, $session);
+		cgi_savesession($session);
+		exit;
+	}
+}
+
+sub cgi_signin ($$;$) {
 	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",
-		fields => [qw(do title page subpage from name password confirm_password email)],
-		header => 1,
+		name => "signin",
+		charset => "utf-8",
 		method => 'POST',
-		validate => {
-			confirm_password => {
-				perl => q{eq $form->field("password")},
-			},
-			email => 'EMAIL',
-		},
 		required => 'NONE',
 		javascript => 0,
 		params => $q,
-		action => $config{cgiurl},
+		action => cgiurl(),
 		header => 0,
-		template => (-e "$config{templatedir}/signin.tmpl" ?
-		              "$config{templatedir}/signin.tmpl" : ""),
-		stylesheet => styleurl(),
+		template => {type => 'div'},
+		stylesheet => 1,
 	);
+	my $buttons=["Login"];
 	
-	$form->field(name => "name", required => 0);
-	$form->field(name => "do", type => "hidden");
-	$form->field(name => "page", type => "hidden");
-	$form->field(name => "title", type => "hidden");
-	$form->field(name => "from", type => "hidden");
-	$form->field(name => "subpage", type => "hidden");
-	$form->field(name => "password", type => "password", required => 0);
-	$form->field(name => "confirm_password", type => "password", required => 0);
-	$form->field(name => "email", required => 0);
-	if ($q->param("do") ne "signin") {
-		$form->text("You need to log in first.");
-	}
+	$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) {
-		# Set required fields based on how form was submitted.
-		my %required=(
-			"Login" => [qw(name password)],
-			"Register" => [qw(name password confirm_password email)],
-			"Mail Password" => [qw(name)],
-		);
-		foreach my $opt (@{$required{$form->submitted}}) {
-			$form->field(name => $opt, required => 1);
-		}
-	
-		# Validate password differently depending on how
-		# form was submitted.
-		if ($form->submitted eq 'Login') {
-			$form->field(
-				name => "password",
-				validate => sub {
-					length $form->field("name") &&
-					shift eq userinfo_get($form->field("name"), 'password');
-				},
-			);
-			$form->field(name => "name", validate => '/^\w+$/');
-		}
-		else {
-			$form->field(name => "password", validate => 'VALUE');
-		}
-		# And make sure the entered name exists when logging
-		# in or sending email, and does not when registering.
-		if ($form->submitted eq 'Register') {
-			$form->field(
-				name => "name",
-				validate => sub {
-					my $name=shift;
-					length $name &&
-					$name=~/$config{wiki_file_regexp}/ &&
-					! userinfo_get($name, "regdate");
-				},
-			);
-		}
-		else {
-			$form->field(
-				name => "name",
-				validate => sub {
-					my $name=shift;
-					length $name &&
-					userinfo_get($name, "regdate");
-				},
-			);
-		}
+		$form->validate;
 	}
-	else {
-		# First time settings.
-		$form->field(name => "name", comment => "use FirstnameLastName");
-		$form->field(name => "confirm_password", comment => "(only needed");
-		$form->field(name => "email",            comment => "for registration)");
-		if ($session->param("name")) {
-			$form->field(name => "name", value => $session->param("name"));
-		}
+
+	if ($returnhtml) {
+		$form=prepform($form, $buttons, $session, $q);
+		return $form->render(submit => $buttons);
 	}
 
-	if ($form->submitted && $form->validate) {
-		if ($form->submitted eq 'Login') {
-			$session->param("name", $form->field("name"));
-			if (defined $form->field("do") && 
-			    $form->field("do") ne 'signin') {
-				print $q->redirect(cgiurl(
-					do => $form->field("do"),
-					page => $form->field("page"),
-					title => $form->field("title"),
-					subpage => $form->field("subpage"),
-					from => $form->field("from"),
-				));
-			}
-			else {
-				print $q->redirect($config{url});
-			}
-		}
-		elsif ($form->submitted eq 'Register') {
-			my $user_name=$form->field('name');
-			if (userinfo_setall($user_name, {
-				           'email' => $form->field('email'),
-				           'password' => $form->field('password'),
-				           'regdate' => time
-				         })) {
-				$form->field(name => "confirm_password", type => "hidden");
-				$form->field(name => "email", type => "hidden");
-				$form->text("Registration successful. Now you can Login.");
-				print $session->header();
-				print misctemplate($form->title, $form->render(submit => ["Login"]));
-			}
-			else {
-				error("Error saving registration.");
-			}
-		}
-		elsif ($form->submitted eq 'Mail Password') {
-			my $user_name=$form->field("name");
-			my $template=HTML::Template->new(
-				filename => "$config{templatedir}/passwordmail.tmpl"
-			);
-			$template->param(
-				user_name => $user_name,
-				user_password => userinfo_get($user_name, "password"),
-				wikiurl => $config{url},
-				wikiname => $config{wikiname},
-				REMOTE_ADDR => $ENV{REMOTE_ADDR},
-			);
-			
-			eval q{use Mail::Sendmail};
-			sendmail(
-				To => userinfo_get($user_name, "email"),
-				From => "$config{wikiname} admin <$config{adminemail}>",
-				Subject => "$config{wikiname} information",
-				Message => $template->output,
-			) or error("Failed to send mail");
-			
-			$form->text("Your password has been emailed to you.");
-			$form->field(name => "name", required => 0);
-			print $session->header();
-			print misctemplate($form->title, $form->render(submit => ["Login", "Register", "Mail Password"]));
-		}
+	showform($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 {
-		print $session->header();
-		print misctemplate($form->title, $form->render(submit => ["Login", "Register", "Mail Password"]));
+		if ($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 ($$) { #{{{
+sub cgi_prefs ($$) {
 	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",
-		fields => [qw(do name password confirm_password email 
-		              subscriptions locked_pages)],
+		name => "preferences",
 		header => 0,
+		charset => "utf-8",
 		method => 'POST',
 		validate => {
-			confirm_password => {
-				perl => q{eq $form->field("password")},
-			},
 			email => 'EMAIL',
 		},
 		required => 'NONE',
 		javascript => 0,
 		params => $q,
-		action => $config{cgiurl},
-		template => (-e "$config{templatedir}/prefs.tmpl" ?
-		              "$config{templatedir}/prefs.tmpl" : ""),
-		stylesheet => styleurl(),
+		action => cgiurl(),
+		template => {type => 'div'},
+		stylesheet => 1,
+		fieldsets => [
+			[login => gettext("Login")],
+			[preferences => gettext("Preferences")],
+			[admin => gettext("Admin")]
+		],
 	);
-	my @buttons=("Save Preferences", "Logout", "Cancel");
+	my $buttons=["Save Preferences", "Logout", "Cancel"];
 	
-	my $user_name=$session->param("name");
-	$form->field(name => "do", type => "hidden");
-	$form->field(name => "name", disabled => 1,
-		value => $user_name, force => 1);
-	$form->field(name => "password", type => "password");
-	$form->field(name => "confirm_password", type => "password");
-	$form->field(name => "subscriptions", size => 50,
-		comment => "(".htmllink("", "GlobList", 1).")");
-	$form->field(name => "locked_pages", size => 50,
-		comment => "(".htmllink("", "GlobList", 1).")");
+	decode_form_utf8($form);
+	run_hooks(formbuilder_setup => sub {
+		shift->(form => $form, cgi => $q, session => $session,
+		        buttons => $buttons);
+	});
+	decode_form_utf8($form);
 	
-	if (! is_admin($user_name)) {
-		$form->field(name => "locked_pages", type => "hidden");
-	}
+	$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"));
-		$form->field(name => "subscriptions", force => 1,
-			value => userinfo_get($user_name, "subscriptions"));
-		$form->field(name => "locked_pages", force => 1,
-			value => userinfo_get($user_name, "locked_pages"));
 	}
 	
 	if ($form->submitted eq 'Logout') {
 		$session->delete();
-		print $q->redirect($config{url});
+		redirect($q, baseurl(undef));
 		return;
 	}
 	elsif ($form->submitted eq 'Cancel') {
-		print $q->redirect($config{url});
+		redirect($q, baseurl(undef));
 		return;
 	}
-	elsif ($form->submitted eq "Save Preferences" && $form->validate) {
-		foreach my $field (qw(password email subscriptions locked_pages)) {
-			if (length $form->field($field)) {
-				userinfo_set($user_name, $field, $form->field($field)) || error("failed to set $field");
-			}
+	elsif ($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("Preferences saved.");
+
+		$form->text(gettext("Preferences saved."));
 	}
 	
-	print $session->header();
-	print misctemplate($form->title, $form->render(submit => \@buttons));
-} #}}}
+	showform($form, $buttons, $session, $q,
+		prefsurl => "", # avoid showing the preferences link
+	);
+}
 
-sub cgi_editpage ($$) { #{{{
+sub cgi_custom_failure ($$$) {
 	my $q=shift;
-	my $session=shift;
+	my $httpstatus=shift;
+	my $message=shift;
 
-	eval q{use CGI::FormBuilder};
-	my $form = CGI::FormBuilder->new(
-		fields => [qw(do rcsinfo subpage from page content comments)],
-		header => 1,
-		method => 'POST',
-		validate => {
-			content => '/.+/',
-		},
-		required => [qw{content}],
-		javascript => 0,
-		params => $q,
-		action => $config{cgiurl},
-		table => 0,
-		template => "$config{templatedir}/editpage.tmpl"
+	print $q->header(
+		-status => $httpstatus,
+		-charset => 'utf-8',
 	);
-	my @buttons=("Save Page", "Preview", "Cancel");
-	
-	# This untaint is safe because titlepage removes any problimatic
-	# characters.
-	my ($page)=titlepage(possibly_foolish_untaint(lc($form->param('page'))));
-	if (! defined $page || ! length $page ||
-	    $page=~/$config{wiki_file_prune_regexp}/ || $page=~/^\//) {
-		error("bad page name");
-	}
-	$page=lc($page);
-	
-	my $file=$page.$config{default_pageext};
-	if (exists $pagesources{lc($page)}) {
-		$file=$pagesources{lc($page)};
-	}
-	my $newfile=0;
-	if (! -e "$config{srcdir}/$file") {
-		$newfile=1;
-	}
-
-	$form->field(name => "do", type => 'hidden');
-	$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 => "comments", type => "text", size => 80);
-	$form->field(name => "content", type => "textarea", rows => 20,
-		cols => 80);
-	$form->tmpl_param("can_commit", $config{rcs});
-	$form->tmpl_param("indexlink", indexlink());
-	$form->tmpl_param("helponformattinglink",
-		htmllink("", "HelpOnFormatting", 1));
-	$form->tmpl_param("styleurl", styleurl());
-	$form->tmpl_param("baseurl", "$config{url}/");
-	if (! $form->submitted) {
-		$form->field(name => "rcsinfo", value => rcs_prepedit($file),
-			force => 1);
+	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}}) {
+		$banned=1;
 	}
-	
-	if ($form->submitted eq "Cancel") {
-		print $q->redirect("$config{url}/".htmlpage($page));
-		return;
+
+	foreach my $b (@{$config{banned_users}}) {
+		if (pagespec_match("", $b,
+			ip => $session->remote_addr(),
+			name => defined $name ? $name : "",
+		)) {
+			$banned=1;
+			last;
+		}
 	}
-	elsif ($form->submitted eq "Preview") {
-		require IkiWiki::Render;
-		$form->tmpl_param("page_preview",
-			htmlize($config{default_pageext},
-				linkify($page, $form->field('content'))));
+
+	if ($banned) {
+		$session->delete();
+		cgi_savesession($session);
+		cgi_custom_failure(
+			$q, "403 Forbidden",
+			gettext("You are banned."));
 	}
-	else {
-		$form->tmpl_param("page_preview", "");
+}
+
+sub cgi_getsession ($) {
+	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 || $@) {
+		my $error = $@;
+		error($error." ".CGI::Session->errstr());
 	}
-	$form->tmpl_param("page_conflict", "");
 	
-	if (! $form->submitted || $form->submitted eq "Preview" || 
-	    ! $form->validate) {
-		if ($form->field("do") eq "create") {
-			my @page_locs;
-			my $best_loc;
-			my ($from)=$form->param('from')=~/$config{wiki_file_regexp}/;
-			if (! defined $from || ! length $from ||
-			    $from ne $form->param('from') ||
-			    $from=~/$config{wiki_file_prune_regexp}/ ||
-			    $from=~/^\// ||
-			    $form->submitted eq "Preview") {
-				@page_locs=$best_loc=$page;
-			}
-			else {
-				my $dir=$from."/";
-				$dir=~s![^/]+/+$!!;
-				
-				if ((defined $form->param('subpage') && length $form->param('subpage')) ||
-				    $page eq '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;
-				}
-			}
+	umask($oldmask);
 
-			@page_locs = grep {
-				! exists $pagesources{lc($_)} &&
-				! page_locked($_, $session, 1)
-			} @page_locs;
-			
-			if (! @page_locs) {
-				# hmm, someone else made the page in the
-				# meantime?
-				print $q->redirect("$config{url}/".htmlpage($page));
-				return;
-			}
-				
-			$form->tmpl_param("page_select", 1);
-			$form->field(name => "page", type => 'select',
-				options => \@page_locs, value => $best_loc);
-			$form->title("creating ".pagetitle($page));
-		}
-		elsif ($form->field("do") eq "edit") {
-			page_locked($page, $session);
-			if (! defined $form->field('content') || 
-			    ! length $form->field('content')) {
-				my $content="";
-				if (exists $pagesources{lc($page)}) {
-					$content=readfile(srcfile($pagesources{lc($page)}));
-					$content=~s/\n/\r\n/g;
-				}
-				$form->field(name => "content", value => $content,
-					force => 1);
-			}
-			$form->tmpl_param("page_select", 0);
-			$form->field(name => "page", type => 'hidden');
-			$form->title("editing ".pagetitle($page));
-		}
-		
-		print $form->render(submit => \@buttons);
-	}
-	else {
-		# save page
-		page_locked($page, $session);
-		
-		my $content=$form->field('content');
-		$content=~s/\r\n/\n/g;
-		$content=~s/\r/\n/g;
-		writefile($file, $config{srcdir}, $content);
-		
-		my $message="web commit ";
-		if (length $session->param("name")) {
-			$message.="by ".$session->param("name");
-		}
-		else {
-			$message.="from $ENV{REMOTE_ADDR}";
-		}
-		if (defined $form->field('comments') &&
-		    length $form->field('comments')) {
-			$message.=": ".$form->field('comments');
-		}
-		
-		if ($config{rcs}) {
-			if ($newfile) {
-				rcs_add($file);
-			}
-			# prevent deadlock with post-commit hook
-			unlockwiki();
-			# presumably the commit will trigger an update
-			# of the wiki
-			my $conflict=rcs_commit($file, $message,
-				$form->field("rcsinfo"));
-		
-			if (defined $conflict) {
-				$form->field(name => "rcsinfo", value => rcs_prepedit($file),
-					force => 1);
-				$form->tmpl_param("page_conflict", 1);
-				$form->field("content", value => $conflict, force => 1);
-				$form->field("do", "edit)");
-				$form->tmpl_param("page_select", 0);
-				$form->field(name => "page", type => 'hidden');
-				$form->title("editing $page");
-				print $form->render(submit => \@buttons);
-				return;
-			}
-		}
-		else {
-			require IkiWiki::Render;
-			refresh();
-			saveindex();
+	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 ($$) {
+	my $q=shift;
+	my $session = shift;
+
+	if (defined $session->param("name")) {
+		my $sid=$q->param('sid');
+		if (! defined $sid || $sid ne $session->id) {
+			error(gettext("Your login session has expired."));
 		}
-		
-		# The trailing question mark tries to avoid broken
-		# caches and get the most recent version of the page.
-		print $q->redirect("$config{url}/".htmlpage($page)."?updated");
 	}
-} #}}}
+}
+
+sub cgi_savesession ($) {
+	my $session=shift;
+
+	# Force session flush with safe umask.
+	my $oldmask=umask(077);
+	$session->flush;
+	umask($oldmask);
+}
+
+sub cgi (;$$) {
+	my $q=shift;
+	my $session=shift;
 
-sub cgi () { #{{{
 	eval q{use CGI};
-	eval q{use CGI::Session};
-	
-	my $q=CGI->new;
+	error($@) if $@;
+	$CGI::DISABLE_UPLOADS=$config{cgi_disable_uploads};
+
+	if (! $q) {
+		binmode(STDIN);
+		$q=CGI->new;
+		binmode(STDIN, ":utf8");
 	
-	if (exists $hooks{cgi}) {
-		foreach my $id (keys %{$hooks{cgi}}) {
-			$hooks{cgi}{$id}{call}->($q);
-		}
+		run_hooks(cgi => sub { shift->($q) });
 	}
-	
+
 	my $do=$q->param('do');
 	if (! defined $do || ! length $do) {
-		error("\"do\" parameter missing");
+		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();
 	
-	# Things that do not need a session.
-	if ($do eq 'recentchanges') {
-		cgi_recentchanges($q);
-		return;
+	if (! $session) {
+		$session=cgi_getsession($q);
 	}
-	elsif ($do eq 'hyperestraier') {
-		cgi_hyperestraier();
+	
+	# Auth hooks can sign a user in.
+	if ($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 => defined $session->param("email") ? $session->param("email") : "",
+					password => "",
+					regdate => time,
+				}) || error("failed adding user");
+			}
+		}
 	}
 	
-	CGI::Session->name("ikiwiki_session_$config{wikiname}");
+	check_banned($q, $session);
 	
-	my $oldmask=umask(077);
-	my $session = CGI::Session->new("driver:DB_File", $q,
-		{ FileName => "$config{wikistatedir}/sessions.db" });
-	umask($oldmask);
-	
-	# Everything below this point needs the user to be signed in.
-	if ((! $config{anonok} &&
-	     (! defined $session->param("name") ||
-	     ! userinfo_get($session->param("name"), "regdate"))) || $do eq 'signin') {
+	run_hooks(sessioncgi => sub { shift->($q, $session) });
+
+	if ($do eq 'signin') {
 		cgi_signin($q, $session);
-	
-		# Force session flush with safe umask.
-		my $oldmask=umask(077);
-		$session->flush;
-		umask($oldmask);
-		
-		return;
-	}
-	
-	if ($do eq 'create' || $do eq 'edit') {
-		cgi_editpage($q, $session);
+		cgi_savesession($session);
 	}
 	elsif ($do eq 'prefs') {
 		cgi_prefs($q, $session);
 	}
-	elsif ($do eq 'blog') {
-		my $page=titlepage(lc($q->param('title')));
-		# if the page already exists, munge it to be unique
-		my $from=$q->param('from');
-		my $add="";
-		while (exists $oldpagemtime{"$from/$page$add"}) {
-			$add=1 unless length $add;
-			$add++;
-		}
-		$q->param('page', $page.$add);
-		# now run same as create
-		$q->param('do', 'create');
-		cgi_editpage($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;
+
+	print "Content-type: text/html\n\n";
+	print cgitemplate(undef, gettext("Error"),
+		"<p class=\"error\">".gettext("Error").": $message</p>");
+	die $@;
+}
 
 1