#!/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); } our $program_to_wrap = $0; sub gen_wrapper () { $config{srcdir}=File::Spec->rel2abs($config{srcdir}); $config{destdir}=File::Spec->rel2abs($config{destdir}); my $this=File::Spec->rel2abs($program_to_wrap); 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. # # A lot of cgi wrapper processes can potentially build # up and clog an otherwise unloaded web server. To # partially avoid this, when a GET comes in and the lock # is already held, rather than blocking a html page is # constructed that retries. This is enabled by setting # cgi_overload_delay. if (defined $config{cgi_overload_delay} && $config{cgi_overload_delay} =~/^[0-9]+/) { my $i=int($config{cgi_overload_delay}); $pre_exec.="#define CGI_OVERLOAD_DELAY $i\n" if $i > 0; my $msg=gettext("Please wait"); $msg=~s/"/\\"/g; $pre_exec.='#define CGI_PLEASE_WAIT_TITLE "'.$msg."\"\n"; if (defined $config{cgi_overload_message} && length $config{cgi_overload_message}) { $msg=$config{cgi_overload_message}; $msg=~s/"/\\"/g; } $pre_exec.='#define CGI_PLEASE_WAIT_BODY "'.$msg."\"\n"; } $pre_exec.=<<"EOF"; lockfd=open("$config{wikistatedir}/cgilock", O_CREAT | O_RDWR, 0666); if (lockfd != -1) { #ifdef CGI_OVERLOAD_DELAY char *request_method = getenv("REQUEST_METHOD"); if (request_method && strcmp(request_method, "GET") == 0) { if (lockf(lockfd, F_TLOCK, 0) == 0) { set_cgilock_fd(lockfd); } else { printf("Content-Type: text/html\\nRefresh: %i; URL=%s\\n\\n%s

%s

", CGI_OVERLOAD_DELAY, getenv("REQUEST_URI"), CGI_PLEASE_WAIT_TITLE, CGI_PLEASE_WAIT_BODY); exit(0); } } else if (lockf(lockfd, F_LOCK, 0) == 0) { set_cgilock_fd(lockfd); } #else if (lockf(lockfd, F_LOCK, 0) == 0) { set_cgilock_fd(lockfd); } #endif } 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($wrapper), <<"EOF"); /* A wrapper for ikiwiki, can be safely made suid. */ #include #include #include #include #include #include #include #include extern char **environ; char *newenviron[$#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; } void set_cgilock_fd (int lockfd) { char *fd_s=malloc(8); sprintf(fd_s, "%i", lockfd); setenv("IKIWIKI_CGILOCK_FD", fd_s, 1); } 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, split(' ', 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)); } 1