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 4ca94b9f43ff45033345c16b6d236b9f02e3da1b..b35bf54c111265cc26e24fc1cd6c7d381816822b 100644 (file)
--- a/lib/PublicInbox/Spawn.pm
+++ b/lib/PublicInbox/Spawn.pm
@@ -201,62 +201,90 @@ 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)+8+sizeof(int)+8];
+       char pad[sizeof(struct cmsghdr) + 16 + SEND_FD_SPACE];
 };
 
-int send_fd(int sockfd, int fd)
+int send_cmd4(PerlIO *s, SV *svfds, SV *data, int flags)
 {
        struct msghdr msg = { 0 };
-       struct iovec iov;
        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;
 
-       iov.iov_base = &msg.msg_namelen;
-       iov.iov_len = 1;
+       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;
-       msg.msg_control = &cmsg.hdr;
-       msg.msg_controllen = CMSG_SPACE(sizeof(int));
-
-       cmsg.hdr.cmsg_level = SOL_SOCKET;
-       cmsg.hdr.cmsg_type = SCM_RIGHTS;
-       cmsg.hdr.cmsg_len = CMSG_LEN(sizeof(int));
-       *(int *)CMSG_DATA(&cmsg.hdr) = fd;
-
-       return sendmsg(sockfd, &msg, 0) >= 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);
+               }
+       }
+       return sendmsg(PerlIO_fileno(s), &msg, flags) >= 0;
 }
 
-int recv_fd(int sockfd)
+void recv_cmd4(PerlIO *s, SV *buf, STRLEN n)
 {
        union my_cmsg cmsg = { 0 };
        struct msghdr msg = { 0 };
        struct iovec iov;
-       int fd = -1;
-
-       iov.iov_base = &msg.msg_namelen;
-       iov.iov_len = 1;
+       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(sizeof(int));
-
-       if (recvmsg(sockfd, &msg, 0) <= 0)
-               return -1;
-
-       errno = EDOM;
-       if (cmsg.hdr.cmsg_level == SOL_SOCKET &&
-                       cmsg.hdr.cmsg_type == SCM_RIGHTS &&
-                       cmsg.hdr.cmsg_len == CMSG_LEN(sizeof(int)))
-               fd = *(int *)CMSG_DATA(&cmsg.hdr);
-
-       return fd;
+       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
@@ -275,7 +303,8 @@ 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 . $fdpass . $set_nodatacow';
+               eval 'use Inline C => $vfork_spawn.$fdpass.$set_nodatacow';
+                       # . ', BUILD_NOISY => 1';
                my $err = $@;
                my $ndc_err;
                if ($err && $set_nodatacow) { # missing Linux kernel headers
@@ -303,14 +332,6 @@ unless ($set_nodatacow) {
        *nodatacow_fd = \&PublicInbox::NDC_PP::nodatacow_fd;
        *nodatacow_dir = \&PublicInbox::NDC_PP::nodatacow_dir;
 }
-unless (__PACKAGE__->can('recv_fd')) {
-       eval { # try the XS IO::FDPass package
-               require IO::FDPass;
-               no warnings 'once';
-               *recv_fd = \&IO::FDPass::recv;
-               *send_fd = \&IO::FDPass::send;
-       };
-}
 
 undef $set_nodatacow;
 undef $vfork_spawn;