lei: less error-prone FD mapping

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

diff --git a/lib/PublicInbox/Spawn.pm b/lib/PublicInbox/Spawn.pm
index 7d0d95977c813c503a0f5fe20ed9f46b819eac21..1842899c6ac16929ae76aaa2d13b43831da6d094 100644 (file)
--- a/lib/PublicInbox/Spawn.pm
+++ b/lib/PublicInbox/Spawn.pm
@@ -209,20 +209,23 @@ my $fdpass = <<'FDPASS';
 #include <sys/socket.h>
 
 #if defined(CMSG_SPACE) && defined(CMSG_LEN)
-struct my_3fds { int fds[3]; };
+#define SEND_FD_CAPA 10
+#define SEND_FD_SPACE (SEND_FD_CAPA * sizeof(int))
 union my_cmsg {
        struct cmsghdr hdr;
-       char pad[sizeof(struct cmsghdr)+ 8 + sizeof(struct my_3fds) + 8];
+       char pad[sizeof(struct cmsghdr) + 16 + SEND_FD_SPACE];
 };
 
-int send_cmd4(PerlIO *s, int in, int out, int err, SV *data, int flags)
+SV *send_cmd4(PerlIO *s, SV *svfds, SV *data, int flags)
 {
        struct msghdr msg = { 0 };
-       struct iovec iov;
        union my_cmsg cmsg = { 0 };
-       int *fdp;
-       size_t i;
        STRLEN dlen = 0;
+       struct iovec iov;
+       ssize_t sent;
+       AV *fds = (AV *)SvRV(svfds);
+       I32 i, nfds = av_len(fds) + 1;
+       int *fdp;
 
        if (SvOK(data)) {
                iov.iov_base = SvPV(data, dlen);
@@ -234,17 +237,24 @@ int send_cmd4(PerlIO *s, int in, int out, int err, SV *data, int flags)
        }
        msg.msg_iov = &iov;
        msg.msg_iovlen = 1;
-       msg.msg_control = &cmsg.hdr;
-       msg.msg_controllen = CMSG_SPACE(sizeof(struct my_3fds));
-
-       cmsg.hdr.cmsg_level = SOL_SOCKET;
-       cmsg.hdr.cmsg_type = SCM_RIGHTS;
-       cmsg.hdr.cmsg_len = CMSG_LEN(sizeof(struct my_3fds));
-       fdp = (int *)CMSG_DATA(&cmsg.hdr);
-       *fdp++ = in;
-       *fdp++ = out;
-       *fdp++ = err;
-       return sendmsg(PerlIO_fileno(s), &msg, flags) >= 0;
+       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);
+               }
+       }
+       sent = sendmsg(PerlIO_fileno(s), &msg, flags);
+       return sent >= 0 ? newSViv(sent) : &PL_sv_undef;
 }
 
 void recv_cmd4(PerlIO *s, SV *buf, STRLEN n)
@@ -252,7 +262,7 @@ void recv_cmd4(PerlIO *s, SV *buf, STRLEN n)
        union my_cmsg cmsg = { 0 };
        struct msghdr msg = { 0 };
        struct iovec iov;
-       size_t i;
+       ssize_t i;
        Inline_Stack_Vars;
        Inline_Stack_Reset;
 
@@ -263,17 +273,18 @@ void recv_cmd4(PerlIO *s, SV *buf, STRLEN n)
        msg.msg_iov = &iov;
        msg.msg_iovlen = 1;
        msg.msg_control = &cmsg.hdr;
-       msg.msg_controllen = CMSG_SPACE(sizeof(struct my_3fds));
+       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);
+               Inline_Stack_Push(&PL_sv_undef);
+       else
+               SvCUR_set(buf, i);
        if (i > 0 && cmsg.hdr.cmsg_level == SOL_SOCKET &&
-                       cmsg.hdr.cmsg_type == SCM_RIGHTS &&
-                       cmsg.hdr.cmsg_len == CMSG_LEN(sizeof(struct my_3fds))) {
+                       cmsg.hdr.cmsg_type == SCM_RIGHTS) {
+               size_t len = cmsg.hdr.cmsg_len;
                int *fdp = (int *)CMSG_DATA(&cmsg.hdr);
-               for (i = 0; i < 3; i++)
+               for (i = 0; CMSG_LEN((i + 1) * sizeof(int)) <= len; i++)
                        Inline_Stack_Push(sv_2mortal(newSViv(*fdp++)));
        }
        Inline_Stack_Done;
@@ -332,7 +343,7 @@ undef $fdpass;
 sub which ($) {
        my ($file) = @_;
        return $file if index($file, '/') >= 0;
-       foreach my $p (split(':', $ENV{PATH})) {
+       for my $p (split(/:/, $ENV{PATH})) {
                $p .= "/$file";
                return $p if -x $p;
        }
@@ -341,8 +352,7 @@ sub which ($) {
 
 sub spawn ($;$$) {
        my ($cmd, $env, $opts) = @_;
-       my $f = which($cmd->[0]);
-       defined $f or die "$cmd->[0]: command not found\n";
+       my $f = which($cmd->[0]) // die "$cmd->[0]: command not found\n";
        my @env;
        $opts ||= {};
 
@@ -354,7 +364,7 @@ sub spawn ($;$$) {
        for my $child_fd (0..2) {
                my $parent_fd = $opts->{$child_fd};
                if (defined($parent_fd) && $parent_fd !~ /\A[0-9]+\z/) {
-                       defined(my $fd = fileno($parent_fd)) or
+                       my $fd = fileno($parent_fd) //
                                        die "$parent_fd not an IO GLOB? $!";
                        $parent_fd = $fd;
                }
@@ -363,7 +373,7 @@ sub spawn ($;$$) {
        my $rlim = [];
 
        foreach my $l (@RLIMITS) {
-               defined(my $v = $opts->{$l}) or next;
+               my $v = $opts->{$l} // next;
                my $r = eval "require BSD::Resource; BSD::Resource::$l();";
                unless (defined $r) {
                        warn "$l undefined by BSD::Resource: $@\n";