]> git.vanrenterghem.biz Git - git.ikiwiki.info.git/blobdiff - IkiWiki/Wrapper.pm
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[git.ikiwiki.info.git] / IkiWiki / Wrapper.pm
index 52a7ca2c70e4ab05b45e5b3c2b852e43e57731f0..b46bc6aa9794abdca46f68c8dc753e88daf7019b 100644 (file)
 #!/usr/bin/perl
 
+package IkiWiki;
+
 use warnings;
 use strict;
-use Cwd q{abs_path};
+use File::Spec;
 use Data::Dumper;
 use IkiWiki;
 
-package 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 () { #{{{
-       $config{srcdir}=abs_path($config{srcdir});
-       $config{destdir}=abs_path($config{destdir});
-       my $this=abs_path($0);
+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 $this) {
-               error("$this doesn't seem to be executable");
+               error(sprintf(gettext("%s doesn't seem to be executable"), $this));
        }
 
        if ($config{setup}) {
-               error("cannot create a wrapper that uses a setup file");
+               error(gettext("cannot create a wrapper that uses a setup file"));
        }
        my $wrapper=possibly_foolish_untaint($config{wrapper});
        if (! defined $wrapper || ! length $wrapper) {
-               error("wrapper filename not specified");
+               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} if $config{cgi};
+                      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"
+               $envsave.=<<"EOF";
        if ((s=getenv("$var")))
-               asprintf(&newenviron[i++], "%s=%s", "$var", s);
+               addenv("$var", s);
 EOF
        }
-       if ($config{rcs} eq "svn" && $config{notify}) {
-               # Support running directly as hooks/post-commit by passing
-               # $2 in REV in the environment.
-               $envsave.=<<"EOF"
-       if (argc == 3)
-               asprintf(&newenviron[i++], "REV=%s", argv[2]);
-       else if ((s=getenv("REV")))
-               asprintf(&newenviron[i++], "%s=%s", "REV", s);
+       
+       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;
+       $configstring=~s/\n/\\n/g;
        
-       open(OUT, ">$wrapper.c") || error("failed to write $wrapper.c: $!");;
-       print OUT <<"EOF";
+       writefile(basename("$wrapper.c"), dirname($wrapper), <<"EOF");
 /* A wrapper for ikiwiki, can be safely made suid. */
-#define _GNU_SOURCE
 #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;
+}
+
+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) {
-       /* Sanitize environment. */
+       int lockfd=-1;
        char *s;
-       char *newenviron[$#envsave+5];
-       int i=0;
+
+$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("failed to run $this");
+       perror("exec $this");
        exit(1);
+#endif
 }
 EOF
-       close OUT;
-       if (system("gcc", "$wrapper.c", "-o", $wrapper) != 0) {
-               error("failed to compile $wrapper.c");
+
+       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)) {
-               error("chmod $wrapper: $!");
+           ! chmod(oct($config{wrappermode}), "$wrapper.new")) {
+               error("chmod $wrapper.new: $!");
        }
-       print "successfully generated $wrapper\n";
-} #}}}
+       if (! rename("$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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