# This is a fork of the (for now) unmaintained Sys::Syscall 0.25, # specifically the Debian libsys-syscall-perl 0.25-6 version to # fix upstream regressions in 0.25. # # This license differs from the rest of public-inbox # # This module is Copyright (c) 2005 Six Apart, Ltd. # Copyright (C) 2019 all contributors # # All rights reserved. # # You may distribute under the terms of either the GNU General Public # License or the Artistic License, as specified in the Perl README file. package PublicInbox::Syscall; use strict; use POSIX qw(ENOSYS SEEK_CUR); use Config; require Exporter; use vars qw(@ISA @EXPORT_OK %EXPORT_TAGS $VERSION); $VERSION = "0.25"; @ISA = qw(Exporter); @EXPORT_OK = qw(sendfile epoll_ctl epoll_create epoll_wait EPOLLIN EPOLLOUT EPOLLERR EPOLLHUP EPOLLRDBAND EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD EPOLLEXCLUSIVE); %EXPORT_TAGS = (epoll => [qw(epoll_ctl epoll_create epoll_wait EPOLLIN EPOLLOUT EPOLLERR EPOLLHUP EPOLLRDBAND EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD EPOLLEXCLUSIVE)], sendfile => [qw(sendfile)], ); use constant EPOLLIN => 1; use constant EPOLLOUT => 4; use constant EPOLLERR => 8; use constant EPOLLHUP => 16; use constant EPOLLRDBAND => 128; use constant EPOLLEXCLUSIVE => (1 << 28); use constant EPOLL_CTL_ADD => 1; use constant EPOLL_CTL_DEL => 2; use constant EPOLL_CTL_MOD => 3; our $loaded_syscall = 0; sub _load_syscall { # props to Gaal for this! return if $loaded_syscall++; my $clean = sub { delete @INC{qw}; }; $clean->(); # don't trust modules before us my $rv = eval { require 'syscall.ph'; 1 } || eval { require 'sys/syscall.ph'; 1 }; $clean->(); # don't require modules after us trust us return $rv; } our ($sysname, $nodename, $release, $version, $machine) = POSIX::uname(); our ( $SYS_epoll_create, $SYS_epoll_ctl, $SYS_epoll_wait, $SYS_sendfile, $SYS_readahead, ); our $no_deprecated = 0; if ($^O eq "linux") { # whether the machine requires 64-bit numbers to be on 8-byte # boundaries. my $u64_mod_8 = 0; # if we're running on an x86_64 kernel, but a 32-bit process, # we need to use the i386 syscall numbers. if ($machine eq "x86_64" && $Config{ptrsize} == 4) { $machine = "i386"; } # Similarly for mips64 vs mips if ($machine eq "mips64" && $Config{ptrsize} == 4) { $machine = "mips"; } if ($machine =~ m/^i[3456]86$/) { $SYS_epoll_create = 254; $SYS_epoll_ctl = 255; $SYS_epoll_wait = 256; $SYS_sendfile = 187; # or 64: 239 $SYS_readahead = 225; } elsif ($machine eq "x86_64") { $SYS_epoll_create = 213; $SYS_epoll_ctl = 233; $SYS_epoll_wait = 232; $SYS_sendfile = 40; $SYS_readahead = 187; } elsif ($machine =~ m/^parisc/) { $SYS_epoll_create = 224; $SYS_epoll_ctl = 225; $SYS_epoll_wait = 226; $SYS_sendfile = 122; # sys_sendfile64=209 $SYS_readahead = 207; $u64_mod_8 = 1; } elsif ($machine =~ m/^ppc64/) { $SYS_epoll_create = 236; $SYS_epoll_ctl = 237; $SYS_epoll_wait = 238; $SYS_sendfile = 186; # (sys32_sendfile). sys32_sendfile64=226 (64 bit processes: sys_sendfile64=186) $SYS_readahead = 191; # both 32-bit and 64-bit vesions $u64_mod_8 = 1; } elsif ($machine eq "ppc") { $SYS_epoll_create = 236; $SYS_epoll_ctl = 237; $SYS_epoll_wait = 238; $SYS_sendfile = 186; # sys_sendfile64=226 $SYS_readahead = 191; $u64_mod_8 = 1; } elsif ($machine =~ m/^s390/) { $SYS_epoll_create = 249; $SYS_epoll_ctl = 250; $SYS_epoll_wait = 251; $SYS_sendfile = 187; # sys_sendfile64=223 $SYS_readahead = 222; $u64_mod_8 = 1; } elsif ($machine eq "ia64") { $SYS_epoll_create = 1243; $SYS_epoll_ctl = 1244; $SYS_epoll_wait = 1245; $SYS_sendfile = 1187; $SYS_readahead = 1216; $u64_mod_8 = 1; } elsif ($machine eq "alpha") { # natural alignment, ints are 32-bits $SYS_sendfile = 370; # (sys_sendfile64) $SYS_epoll_create = 407; $SYS_epoll_ctl = 408; $SYS_epoll_wait = 409; $SYS_readahead = 379; $u64_mod_8 = 1; } elsif ($machine eq "aarch64") { $SYS_epoll_create = 20; # (sys_epoll_create1) $SYS_epoll_ctl = 21; $SYS_epoll_wait = 22; # (sys_epoll_pwait) $SYS_sendfile = 71; # (sys_sendfile64) $SYS_readahead = 213; $u64_mod_8 = 1; $no_deprecated = 1; } elsif ($machine =~ m/arm(v\d+)?.*l/) { # ARM OABI $SYS_epoll_create = 250; $SYS_epoll_ctl = 251; $SYS_epoll_wait = 252; $SYS_sendfile = 187; $SYS_readahead = 225; $u64_mod_8 = 1; } elsif ($machine =~ m/^mips64/) { $SYS_sendfile = 5039; $SYS_epoll_create = 5207; $SYS_epoll_ctl = 5208; $SYS_epoll_wait = 5209; $SYS_readahead = 5179; $u64_mod_8 = 1; } elsif ($machine =~ m/^mips/) { $SYS_sendfile = 4207; $SYS_epoll_create = 4248; $SYS_epoll_ctl = 4249; $SYS_epoll_wait = 4250; $SYS_readahead = 4223; $u64_mod_8 = 1; } else { # as a last resort, try using the *.ph files which may not # exist or may be wrong _load_syscall(); $SYS_epoll_create = eval { &SYS_epoll_create; } || 0; $SYS_epoll_ctl = eval { &SYS_epoll_ctl; } || 0; $SYS_epoll_wait = eval { &SYS_epoll_wait; } || 0; $SYS_readahead = eval { &SYS_readahead; } || 0; } if ($u64_mod_8) { *epoll_wait = \&epoll_wait_mod8; *epoll_ctl = \&epoll_ctl_mod8; } else { *epoll_wait = \&epoll_wait_mod4; *epoll_ctl = \&epoll_ctl_mod4; } } elsif ($^O eq "freebsd") { if ($ENV{FREEBSD_SENDFILE}) { # this is still buggy and in development $SYS_sendfile = 393; # old is 336 } } ############################################################################ # sendfile functions ############################################################################ unless ($SYS_sendfile) { _load_syscall(); $SYS_sendfile = eval { &SYS_sendfile; } || 0; } sub sendfile_defined { return $SYS_sendfile ? 1 : 0; } if ($^O eq "linux" && $SYS_sendfile) { *sendfile = \&sendfile_linux; } elsif ($^O eq "freebsd" && $SYS_sendfile) { *sendfile = \&sendfile_freebsd; } else { *sendfile = \&sendfile_noimpl; } sub sendfile_noimpl { $! = ENOSYS; return -1; } # C: ssize_t sendfile(int out_fd, int in_fd, off_t *offset, size_t count) # Perl: sendfile($write_fd, $read_fd, $max_count) --> $actually_sent sub sendfile_linux { return syscall( $SYS_sendfile, $_[0] + 0, # fd $_[1] + 0, # fd 0, # don't keep track of offset. callers can lseek and keep track. $_[2] + 0 # count ); } sub sendfile_freebsd { my $offset = POSIX::lseek($_[1]+0, 0, SEEK_CUR) + 0; my $ct = $_[2] + 0; my $sbytes_buf = "\0" x 8; my $rv = syscall( $SYS_sendfile, $_[1] + 0, # fd (from) $_[0] + 0, # socket (to) $offset, $ct, 0, # struct sf_hdtr *hdtr $sbytes_buf, # off_t *sbytes 0); # flags return $rv if $rv < 0; my $set = unpack("L", $sbytes_buf); POSIX::lseek($_[1]+0, SEEK_CUR, $set); return $set; } ############################################################################ # epoll functions ############################################################################ sub epoll_defined { return $SYS_epoll_create ? 1 : 0; } # ARGS: (size) -- but in modern Linux 2.6, the # size doesn't even matter (radix tree now, not hash) sub epoll_create { return -1 unless defined $SYS_epoll_create; my $epfd = eval { syscall($SYS_epoll_create, $no_deprecated ? 0 : ($_[0]||100)+0) }; return -1 if $@; return $epfd; } # epoll_ctl wrapper # ARGS: (epfd, op, fd, events_mask) sub epoll_ctl_mod4 { syscall($SYS_epoll_ctl, $_[0]+0, $_[1]+0, $_[2]+0, pack("LLL", $_[3], $_[2], 0)); } sub epoll_ctl_mod8 { syscall($SYS_epoll_ctl, $_[0]+0, $_[1]+0, $_[2]+0, pack("LLLL", $_[3], 0, $_[2], 0)); } # epoll_wait wrapper # ARGS: (epfd, maxevents, timeout (milliseconds), arrayref) # arrayref: values modified to be [$fd, $event] our $epoll_wait_events; our $epoll_wait_size = 0; sub epoll_wait_mod4 { # resize our static buffer if requested size is bigger than we've ever done if ($_[1] > $epoll_wait_size) { $epoll_wait_size = $_[1]; $epoll_wait_events = "\0" x 12 x $epoll_wait_size; } my $ct = syscall($SYS_epoll_wait, $_[0]+0, $epoll_wait_events, $_[1]+0, $_[2]+0); for (0..$ct-1) { @{$_[3]->[$_]}[1,0] = unpack("LL", substr($epoll_wait_events, 12*$_, 8)); } return $ct; } sub epoll_wait_mod8 { # resize our static buffer if requested size is bigger than we've ever done if ($_[1] > $epoll_wait_size) { $epoll_wait_size = $_[1]; $epoll_wait_events = "\0" x 16 x $epoll_wait_size; } my $ct; if ($no_deprecated) { $ct = syscall($SYS_epoll_wait, $_[0]+0, $epoll_wait_events, $_[1]+0, $_[2]+0, undef); } else { $ct = syscall($SYS_epoll_wait, $_[0]+0, $epoll_wait_events, $_[1]+0, $_[2]+0); } for (0..$ct-1) { # 16 byte epoll_event structs, with format: # 4 byte mask [idx 1] # 4 byte padding (we put it into idx 2, useless) # 8 byte data (first 4 bytes are fd, into idx 0) @{$_[3]->[$_]}[1,2,0] = unpack("LLL", substr($epoll_wait_events, 16*$_, 12)); } return $ct; } 1; =head1 WARRANTY This is free software. IT COMES WITHOUT WARRANTY OF ANY KIND. =head1 AUTHORS Brad Fitzpatrick