diff options
Diffstat (limited to 'IkiWiki/Wrapper.pm')
| -rw-r--r-- | IkiWiki/Wrapper.pm | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/IkiWiki/Wrapper.pm b/IkiWiki/Wrapper.pm new file mode 100644 index 000000000..84b4b5a2f --- /dev/null +++ b/IkiWiki/Wrapper.pm @@ -0,0 +1,291 @@ +#!/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<html><head><title>%s</title><head><body><p>%s</p></body></html>", + 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($wrapper), <<"EOF"); +/* A wrapper for ikiwiki, can be safely made suid. */ +#include <stdio.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <sys/file.h> + +extern char **environ; +char *newenviron[$#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; +} + +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 |