#!/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=malloc(8); sprintf(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; 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) { char *s; $check_commit_hook @wrapper_hooks $envsave newenviron[i++]="HOME=$ENV{HOME}"; 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); } $pre_exec execl("$this", "$this", NULL); perror("exec $this"); exit(1); } 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. printf(gettext("successfully generated %s"), $wrapper); print "\n"; } 1