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#!/usr/bin/perl
package IkiWiki;
use warnings;
use strict;
use File::Spec;
use Data::Dumper;
use IkiWiki;
sub gen_wrapper () {
$config{srcdir}=File::Spec->rel2abs($config{srcdir});
$config{destdir}=File::Spec->rel2abs($config{destdir});
my $this=File::Spec->rel2abs($0);
if (! -x $this) {
error(sprintf(gettext("%s doesn't seem to be executable"), $this));
}
if ($config{setup}) {
error(gettext("cannot create a wrapper that uses a setup file"));
}
my $wrapper=possibly_foolish_untaint($config{wrapper});
if (! defined $wrapper || ! length $wrapper) {
error(gettext("wrapper filename not specified"));
}
delete $config{wrapper};
my @envsave;
push @envsave, qw{REMOTE_ADDR QUERY_STRING REQUEST_METHOD REQUEST_URI
CONTENT_TYPE CONTENT_LENGTH GATEWAY_INTERFACE
HTTP_COOKIE REMOTE_USER HTTPS REDIRECT_STATUS
REDIRECT_URL} if $config{cgi};
my $envsave="";
foreach my $var (@envsave) {
$envsave.=<<"EOF";
if ((s=getenv("$var")))
addenv("$var", s);
EOF
}
my @wrapper_hooks;
run_hooks(genwrapper => sub { push @wrapper_hooks, shift->() });
my $check_commit_hook="";
my $pre_exec="";
if ($config{post_commit}) {
# Optimise checking !commit_hook_enabled() ,
# so that ikiwiki does not have to be started if the
# hook is disabled.
#
# Note that perl's flock may be implemented using fcntl
# or lockf on some systems. If so, and if there is no
# interop between the locking systems, the true C flock will
# always succeed, and this optimisation won't work.
# The perl code will later correctly check the lock,
# so the right thing will still happen, though without
# the benefit of this optimisation.
$check_commit_hook=<<"EOF";
{
int fd=open("$config{wikistatedir}/commitlock", O_CREAT | O_RDWR, 0666);
if (fd != -1) {
if (flock(fd, LOCK_SH | LOCK_NB) != 0)
exit(0);
close(fd);
}
}
EOF
}
elsif ($config{cgi}) {
# Avoid more than one ikiwiki cgi running at a time by
# taking a cgi lock. Since ikiwiki uses several MB of
# memory, a pile up of processes could cause thrashing
# otherwise. The fd of the lock is stored in
# IKIWIKI_CGILOCK_FD so unlockwiki can close it.
$pre_exec=<<"EOF";
{
int fd=open("$config{wikistatedir}/cgilock", O_CREAT | O_RDWR, 0666);
if (fd != -1 && flock(fd, LOCK_EX) == 0) {
char *fd_s;
asprintf(&fd_s, "%i", fd);
setenv("IKIWIKI_CGILOCK_FD", fd_s, 1);
}
}
EOF
}
$Data::Dumper::Indent=0; # no newlines
my $configstring=Data::Dumper->Dump([\%config], ['*config']);
$configstring=~s/\\/\\\\/g;
$configstring=~s/"/\\"/g;
$configstring=~s/\n/\\n/g;
writefile(basename("$wrapper.c"), dirname($wrapper), <<"EOF");
/* A wrapper for ikiwiki, can be safely made suid. */
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/file.h>
extern char **environ;
char *newenviron[$#envsave+6];
int i=0;
addenv(char *var, char *val) {
char *s=malloc(strlen(var)+1+strlen(val)+1);
if (!s)
perror("malloc");
sprintf(s, "%s=%s", var, val);
newenviron[i++]=s;
}
int main (int argc, char **argv) {
char *s;
$check_commit_hook
@wrapper_hooks
$envsave
newenviron[i++]="HOME=$ENV{HOME}";
newenviron[i++]="WRAPPED_OPTIONS=$configstring";
newenviron[i]=NULL;
environ=newenviron;
if (setregid(getegid(), -1) != 0 &&
setregid(getegid(), -1) != 0) {
perror("failed to drop real gid");
exit(1);
}
if (setreuid(geteuid(), -1) != 0 &&
setreuid(geteuid(), -1) != 0) {
perror("failed to drop real uid");
exit(1);
}
$pre_exec
execl("$this", "$this", NULL);
perror("exec $this");
exit(1);
}
EOF
my $cc=exists $ENV{CC} ? possibly_foolish_untaint($ENV{CC}) : 'cc';
if (system($cc, "$wrapper.c", "-o", "$wrapper.new") != 0) {
#translators: The parameter is a C filename.
error(sprintf(gettext("failed to compile %s"), "$wrapper.c"));
}
unlink("$wrapper.c");
if (defined $config{wrappergroup}) {
my $gid=(getgrnam($config{wrappergroup}))[2];
if (! defined $gid) {
error(sprintf("bad wrappergroup"));
}
if (! chown(-1, $gid, "$wrapper.new")) {
error("chown $wrapper.new: $!");
}
}
if (defined $config{wrappermode} &&
! chmod(oct($config{wrappermode}), "$wrapper.new")) {
error("chmod $wrapper.new: $!");
}
if (! rename("$wrapper.new", $wrapper)) {
error("rename $wrapper.new $wrapper: $!");
}
#translators: The parameter is a filename.
printf(gettext("successfully generated %s"), $wrapper);
print "\n";
}
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