ipc: start supporting sending/receiving more than 3 FDs

[public-inbox.git] / lib / PublicInbox / Spawn.pm

diff --git a/lib/PublicInbox/Spawn.pm b/lib/PublicInbox/Spawn.pm
index 1ee40503c33f0b014bb6814295d890e3335133e2..b35bf54c111265cc26e24fc1cd6c7d381816822b 100644 (file)
--- a/lib/PublicInbox/Spawn.pm
+++ b/lib/PublicInbox/Spawn.pm
@@ -201,12 +201,100 @@ void nodatacow_dir(const char *dir)
 }
 SET_NODATACOW
 
+# last choice for script/lei, 1st choice for lei internals
+# compatible with PublicInbox::CmdIPC4
+my $fdpass = <<'FDPASS';
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/socket.h>
+
+#if defined(CMSG_SPACE) && defined(CMSG_LEN)
+#define SEND_FD_CAPA 3
+#define SEND_FD_SPACE (SEND_FD_CAPA * sizeof(int))
+union my_cmsg {
+       struct cmsghdr hdr;
+       char pad[sizeof(struct cmsghdr) + 16 + SEND_FD_SPACE];
+};
+
+int send_cmd4(PerlIO *s, SV *svfds, SV *data, int flags)
+{
+       struct msghdr msg = { 0 };
+       union my_cmsg cmsg = { 0 };
+       STRLEN dlen = 0;
+       struct iovec iov;
+       AV *fds = (AV *)SvRV(svfds);
+       I32 i, nfds = av_len(fds) + 1;
+       int *fdp;
+
+       if (SvOK(data)) {
+               iov.iov_base = SvPV(data, dlen);
+               iov.iov_len = dlen;
+       }
+       if (!dlen) { /* must be non-zero */
+               iov.iov_base = &msg.msg_namelen; /* whatever */
+               iov.iov_len = 1;
+       }
+       msg.msg_iov = &iov;
+       msg.msg_iovlen = 1;
+       if (nfds) {
+               if (nfds > SEND_FD_CAPA) {
+                       fprintf(stderr, "FIXME: bump SEND_FD_CAPA=%d\n", nfds);
+                       nfds = SEND_FD_CAPA;
+               }
+               msg.msg_control = &cmsg.hdr;
+               msg.msg_controllen = CMSG_SPACE(nfds * sizeof(int));
+               cmsg.hdr.cmsg_level = SOL_SOCKET;
+               cmsg.hdr.cmsg_type = SCM_RIGHTS;
+               cmsg.hdr.cmsg_len = CMSG_LEN(nfds * sizeof(int));
+               fdp = (int *)CMSG_DATA(&cmsg.hdr);
+               for (i = 0; i < nfds; i++) {
+                       SV **fd = av_fetch(fds, i, 0);
+                       *fdp++ = SvIV(*fd);
+               }
+       }
+       return sendmsg(PerlIO_fileno(s), &msg, flags) >= 0;
+}
+
+void recv_cmd4(PerlIO *s, SV *buf, STRLEN n)
+{
+       union my_cmsg cmsg = { 0 };
+       struct msghdr msg = { 0 };
+       struct iovec iov;
+       size_t i;
+       Inline_Stack_Vars;
+       Inline_Stack_Reset;
+
+       if (!SvOK(buf))
+               sv_setpvn(buf, "", 0);
+       iov.iov_base = SvGROW(buf, n + 1);
+       iov.iov_len = n;
+       msg.msg_iov = &iov;
+       msg.msg_iovlen = 1;
+       msg.msg_control = &cmsg.hdr;
+       msg.msg_controllen = CMSG_SPACE(SEND_FD_SPACE);
+
+       i = recvmsg(PerlIO_fileno(s), &msg, 0);
+       if (i < 0)
+               croak("recvmsg: %s", strerror(errno));
+       SvCUR_set(buf, i);
+       if (i > 0 && cmsg.hdr.cmsg_level == SOL_SOCKET &&
+                       cmsg.hdr.cmsg_type == SCM_RIGHTS) {
+               size_t len = cmsg.hdr.cmsg_len;
+               int *fdp = (int *)CMSG_DATA(&cmsg.hdr);
+               for (i = 0; CMSG_LEN((i + 1) * sizeof(int)) <= len; i++)
+                       Inline_Stack_Push(sv_2mortal(newSViv(*fdp++)));
+       }
+       Inline_Stack_Done;
+}
+#endif /* defined(CMSG_SPACE) && defined(CMSG_LEN) */
+FDPASS
+
 my $inline_dir = $ENV{PERL_INLINE_DIRECTORY} //= (
                $ENV{XDG_CACHE_HOME} //
                ( ($ENV{HOME} // '/nonexistent').'/.cache' )
        ).'/public-inbox/inline-c';
 
-$set_nodatacow = $vfork_spawn = undef unless -d $inline_dir && -w _;
+$set_nodatacow = $vfork_spawn = $fdpass = undef unless -d $inline_dir && -w _;
 if (defined $vfork_spawn) {
        # Inline 0.64 or later has locking in multi-process env,
        # but we support 0.5 on Debian wheezy
@@ -215,13 +303,14 @@ if (defined $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 . $set_nodatacow';
+               eval 'use Inline C => $vfork_spawn.$fdpass.$set_nodatacow';
+                       # . ', BUILD_NOISY => 1';
                my $err = $@;
                my $ndc_err;
                if ($err && $set_nodatacow) { # missing Linux kernel headers
                        $ndc_err = $err;
                        undef $set_nodatacow;
-                       eval 'use Inline C => $vfork_spawn';
+                       eval 'use Inline C => $vfork_spawn . $fdpass';
                }
                flock($fh, LOCK_UN) or die "LOCK_UN failed on $f: $!\n";
                die $err if $err;
@@ -229,7 +318,7 @@ if (defined $vfork_spawn) {
        };
        if ($@) {
                warn "Inline::C failed for vfork: $@\n";
-               $set_nodatacow = $vfork_spawn = undef;
+               $set_nodatacow = $vfork_spawn = $fdpass = undef;
        }
 }
 
@@ -243,8 +332,10 @@ unless ($set_nodatacow) {
        *nodatacow_fd = \&PublicInbox::NDC_PP::nodatacow_fd;
        *nodatacow_dir = \&PublicInbox::NDC_PP::nodatacow_dir;
 }
+
 undef $set_nodatacow;
 undef $vfork_spawn;
+undef $fdpass;
 
 sub which ($) {
        my ($file) = @_;
@@ -295,14 +386,14 @@ sub spawn ($;$$) {
 }
 
 sub popen_rd {
-       my ($cmd, $env, $opts) = @_;
+       my ($cmd, $env, $opt) = @_;
        pipe(my ($r, $w)) or die "pipe: $!\n";
-       $opts ||= {};
-       $opts->{1} = fileno($w);
-       my $pid = spawn($cmd, $env, $opts);
+       $opt ||= {};
+       $opt->{1} = fileno($w);
+       my $pid = spawn($cmd, $env, $opt);
        return ($r, $pid) if wantarray;
        my $ret = gensym;
-       tie *$ret, 'PublicInbox::ProcessPipe', $pid, $r;
+       tie *$ret, 'PublicInbox::ProcessPipe', $pid, $r, @$opt{qw(cb arg)};
        $ret;
 }