-# Copyright (C) 2016 all contributors <meta@public-inbox.org>
+# Copyright (C) 2016-2019 all contributors <meta@public-inbox.org>
# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
#
# This allows vfork to be used for spawning subprocesses if
use warnings;
use base qw(Exporter);
use Symbol qw(gensym);
-use IO::Handle;
use PublicInbox::ProcessPipe;
our @EXPORT_OK = qw/which spawn popen_rd/;
+sub RLIMITS () { qw(RLIMIT_CPU RLIMIT_CORE RLIMIT_DATA) }
my $vfork_spawn = <<'VFORK_SPAWN';
#include <sys/types.h>
#include <sys/uio.h>
+#include <sys/time.h>
+#include <sys/resource.h>
#include <unistd.h>
-#include <alloca.h>
+#include <stdlib.h>
-#define AV_ALLOCA(av, max) alloca((max = (av_len((av)) + 1)) * sizeof(char *))
+/* some platforms need alloca.h, but some don't */
+#if defined(__GNUC__) && !defined(alloca)
+# define alloca(sz) __builtin_alloca(sz)
+#endif
-static void av2c_copy(char **dst, AV *src, I32 max)
-{
- I32 i;
-
- for (i = 0; i < max; i++) {
- SV **sv = av_fetch(src, i, 0);
- dst[i] = sv ? SvPV_nolen(*sv) : 0;
- }
- dst[max] = 0;
-}
+#include <signal.h>
+#include <assert.h>
-static void *deconst(const char *s)
-{
- union { const char *in; void *out; } u;
- u.in = s;
- return u.out;
-}
+/*
+ * From the av_len apidoc:
+ * Note that, unlike what the name implies, it returns
+ * the highest index in the array, so to get the size of
+ * the array you need to use "av_len(av) + 1".
+ * This is unlike "sv_len", which returns what you would expect.
+ */
+#define AV2C_COPY(dst, src) do { \
+ I32 i; \
+ I32 top_index = av_len(src); \
+ I32 real_len = top_index + 1; \
+ I32 capa = real_len + 1; \
+ dst = alloca(capa * sizeof(char *)); \
+ for (i = 0; i < real_len; i++) { \
+ SV **sv = av_fetch(src, i, 0); \
+ dst[i] = SvPV_nolen(*sv); \
+ } \
+ dst[real_len] = 0; \
+} while (0)
/* needs to be safe inside a vfork'ed process */
-static void xerr(const char *msg)
+static void exit_err(int *cerrnum)
{
- struct iovec iov[3];
- const char *err = strerror(errno); /* should be safe in practice */
-
- iov[0].iov_base = deconst(msg);
- iov[0].iov_len = strlen(msg);
- iov[1].iov_base = deconst(err);
- iov[1].iov_len = strlen(err);
- iov[2].iov_base = deconst("\n");
- iov[2].iov_len = 1;
- writev(2, iov, 3);
+ *cerrnum = errno;
_exit(1);
}
-#define REDIR(var,fd) do { \
- if (var != fd && dup2(var, fd) < 0) \
- xerr("error redirecting std"#var ": "); \
-} while (0)
-
/*
- * unstable internal API. This was easy to implement but does not
- * support arbitrary redirects. It'll be updated depending on
+ * unstable internal API. It'll be updated depending on
* whatever we'll need in the future.
* Be sure to update PublicInbox::SpawnPP if this changes
*/
-int public_inbox_fork_exec(int in, int out, int err,
- SV *file, SV *cmdref, SV *envref)
+int pi_fork_exec(SV *redirref, SV *file, SV *cmdref, SV *envref, SV *rlimref,
+ const char *cd)
{
+ AV *redir = (AV *)SvRV(redirref);
AV *cmd = (AV *)SvRV(cmdref);
AV *env = (AV *)SvRV(envref);
+ AV *rlim = (AV *)SvRV(rlimref);
const char *filename = SvPV_nolen(file);
pid_t pid;
char **argv, **envp;
- I32 max;
-
- argv = AV_ALLOCA(cmd, max);
- av2c_copy(argv, cmd, max);
+ sigset_t set, old;
+ int ret, perrnum, cerrnum = 0;
- envp = AV_ALLOCA(env, max);
- av2c_copy(envp, env, max);
+ AV2C_COPY(argv, cmd);
+ AV2C_COPY(envp, env);
+ ret = sigfillset(&set);
+ assert(ret == 0 && "BUG calling sigfillset");
+ ret = sigprocmask(SIG_SETMASK, &set, &old);
+ assert(ret == 0 && "BUG calling sigprocmask to block");
pid = vfork();
if (pid == 0) {
- REDIR(in, 0);
- REDIR(out, 1);
- REDIR(err, 2);
+ int sig;
+ I32 i, child_fd, max = av_len(redir);
+
+ for (child_fd = 0; child_fd <= max; child_fd++) {
+ SV **parent = av_fetch(redir, child_fd, 0);
+ int parent_fd = SvIV(*parent);
+ if (parent_fd == child_fd)
+ continue;
+ if (dup2(parent_fd, child_fd) < 0)
+ exit_err(&cerrnum);
+ }
+ for (sig = 1; sig < NSIG; sig++)
+ signal(sig, SIG_DFL); /* ignore errors on signals */
+ if (*cd && chdir(cd) < 0)
+ exit_err(&cerrnum);
+
+ max = av_len(rlim);
+ for (i = 0; i < max; i += 3) {
+ struct rlimit rl;
+ SV **res = av_fetch(rlim, i, 0);
+ SV **soft = av_fetch(rlim, i + 1, 0);
+ SV **hard = av_fetch(rlim, i + 2, 0);
+
+ rl.rlim_cur = SvIV(*soft);
+ rl.rlim_max = SvIV(*hard);
+ if (setrlimit(SvIV(*res), &rl) < 0)
+ exit_err(&cerrnum);
+ }
+
+ /*
+ * don't bother unblocking, we don't want signals
+ * to the group taking out a subprocess
+ */
execve(filename, argv, envp);
- xerr("execve failed");
+ exit_err(&cerrnum);
+ }
+ perrnum = errno;
+ ret = sigprocmask(SIG_SETMASK, &old, NULL);
+ assert(ret == 0 && "BUG calling sigprocmask to restore");
+ if (cerrnum) {
+ if (pid > 0)
+ waitpid(pid, NULL, 0);
+ pid = -1;
+ errno = cerrnum;
+ } else if (perrnum) {
+ errno = perrnum;
}
-
return (int)pid;
}
VFORK_SPAWN
my $f = "$inline_dir/.public-inbox.lock";
open my $fh, '>', $f or die "failed to open $f: $!\n";
flock($fh, LOCK_EX) or die "LOCK_EX failed on $f: $!\n";
- eval 'use Inline C => $vfork_spawn';
+ eval 'use Inline C => $vfork_spawn'; #, BUILD_NOISY => 1';
my $err = $@;
flock($fh, LOCK_UN) or die "LOCK_UN failed on $f: $!\n";
die $err if $err;
unless (defined $vfork_spawn) {
require PublicInbox::SpawnPP;
- no warnings 'once';
- *public_inbox_fork_exec = *PublicInbox::SpawnPP::public_inbox_fork_exec
+ *pi_fork_exec = \&PublicInbox::SpawnPP::pi_fork_exec
}
sub which ($) {
my ($file) = @_;
+ return $file if index($file, '/') >= 0;
foreach my $p (split(':', $ENV{PATH})) {
$p .= "/$file";
return $p if -x $p;
my @env;
$opts ||= {};
- my %env = $opts->{-env} ? () : %ENV;
- if ($env) {
- foreach my $k (keys %$env) {
- my $v = $env->{$k};
- if (defined $v) {
- $env{$k} = $v;
- } else {
- delete $env{$k};
- }
- }
- }
+ my %env = $env ? (%ENV, %$env) : %ENV;
while (my ($k, $v) = each %env) {
push @env, "$k=$v";
}
- my $in = $opts->{0} || 0;
- my $out = $opts->{1} || 1;
- my $err = $opts->{2} || 2;
- public_inbox_fork_exec($in, $out, $err, $f, $cmd, \@env);
+ my $redir = [];
+ for my $child_fd (0..2) {
+ my $parent_fd = $opts->{$child_fd};
+ if (defined($parent_fd) && $parent_fd !~ /\A[0-9]+\z/) {
+ defined(my $fd = fileno($parent_fd)) or
+ die "$parent_fd not an IO GLOB? $!";
+ $parent_fd = $fd;
+ }
+ $redir->[$child_fd] = $parent_fd // $child_fd;
+ }
+ my $rlim = [];
+
+ foreach my $l (RLIMITS()) {
+ defined(my $v = $opts->{$l}) or next;
+ my $r = eval "require BSD::Resource; BSD::Resource::$l();";
+ unless (defined $r) {
+ warn "$l undefined by BSD::Resource: $@\n";
+ next;
+ }
+ push @$rlim, $r, @$v;
+ }
+ my $cd = $opts->{'-C'} // ''; # undef => NULL mapping doesn't work?
+ my $pid = pi_fork_exec($redir, $f, $cmd, \@env, $rlim, $cd);
+ $pid < 0 ? undef : $pid;
}
sub popen_rd {
my ($cmd, $env, $opts) = @_;
pipe(my ($r, $w)) or die "pipe: $!\n";
$opts ||= {};
- my $blocking = $opts->{Blocking};
- IO::Handle::blocking($r, $blocking) if defined $blocking;
$opts->{1} = fileno($w);
my $pid = spawn($cmd, $env, $opts);
+ return unless defined $pid;
return ($r, $pid) if wantarray;
my $ret = gensym;
tie *$ret, 'PublicInbox::ProcessPipe', $pid, $r;