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#!/usr/bin/perl
package IkiWiki;
use warnings;
use strict;
use File::Spec;
use Data::Dumper;
use IkiWiki;
sub gen_wrappers () {
debug(gettext("generating wrappers.."));
my %origconfig=(%config);
foreach my $wrapper (@{$config{wrappers}}) {
%config=(%origconfig, %{$wrapper});
$config{verbose}=$config{setupverbose}
if exists $config{setupverbose};
$config{syslog}=$config{setupsyslog}
if exists $config{setupsyslog};
delete @config{qw(setupsyslog setupverbose wrappers genwrappers rebuild)};
checkconfig();
if (! $config{cgi} && ! $config{post_commit} &&
! $config{test_receive}) {
$config{post_commit}=1;
}
gen_wrapper();
}
%config=(%origconfig);
}
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
HTTP_HOST SERVER_PORT HTTPS HTTP_ACCEPT
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.
$pre_exec=<<"EOF";
lockfd=open("$config{wikistatedir}/cgilock", O_CREAT | O_RDWR, 0666);
if (lockfd != -1 && lockf(lockfd, F_LOCK, 0) == 0) {
char *fd_s=malloc(8);
sprintf(fd_s, "%i", lockfd);
setenv("IKIWIKI_CGILOCK_FD", fd_s, 1);
}
EOF
}
my $set_background_command='';
if (defined $config{wrapper_background_command} &&
length $config{wrapper_background_command}) {
my $background_command=delete $config{wrapper_background_command};
$set_background_command=~s/"/\\"/g;
$set_background_command='#define BACKGROUND_COMMAND "'.$background_command.'"';
}
$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+7];
int i=0;
void 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) {
int lockfd=-1;
char *s;
$check_commit_hook
@wrapper_hooks
$envsave
newenviron[i++]="HOME=$ENV{HOME}";
newenviron[i++]="PATH=$ENV{PATH}";
newenviron[i++]="WRAPPED_OPTIONS=$configstring";
#ifdef __TINYC__
/* old tcc versions do not support modifying environ directly */
if (clearenv() != 0) {
perror("clearenv");
exit(1);
}
for (; i>0; i--)
putenv(newenviron[i-1]);
#else
newenviron[i]=NULL;
environ=newenviron;
#endif
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
$set_background_command
#ifdef BACKGROUND_COMMAND
if (lockfd != -1) {
close(lockfd);
}
pid_t pid=fork();
if (pid == -1) {
perror("fork");
exit(1);
}
else if (pid == 0) {
execl("$this", "$this", NULL);
perror("exec $this");
exit(1);
}
else {
waitpid(pid, NULL, 0);
if (daemon(1, 0) == 0) {
system(BACKGROUND_COMMAND);
exit(0);
}
else {
perror("daemon");
exit(1);
}
}
#else
execl("$this", "$this", NULL);
perror("exec $this");
exit(1);
#endif
}
EOF
my @cc=exists $ENV{CC} ? possibly_foolish_untaint($ENV{CC}) : 'cc';
push @cc, possibly_foolish_untaint($ENV{CFLAGS}) if exists $ENV{CFLAGS};
if (system(@cc, "$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.
debug(sprintf(gettext("successfully generated %s"), $wrapper));
}
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