tests: attempt compatibility w/ busybox lsof

BusyBox lsof(1) ignores the `-p PID' argument and shows
the open files for every process it knows about.  BusyBox
lsof also lacks the `NODE' column of the non-BusyBox
implementation, so we'll rely on /proc/PID/fd/ in those
cases since the deleted file checks are Linux-only and
it's common to have procfs is mounted on /proc on Linux.

5 files changed, 43 insertions, 37 deletions

diff --git a/lib/PublicInbox/TestCommon.pm b/lib/PublicInbox/TestCommon.pm
index 27a758e4..9c413f43 100644
--- a/lib/PublicInbox/TestCommon.pm
+++ b/lib/PublicInbox/TestCommon.pm
@@ -29,7 +29,7 @@ BEGIN {
                 tcp_host_port test_lei lei lei_ok $lei_out $lei_err $lei_opt
                 test_httpd xbail require_cmd is_xdeeply tail_f
                 ignore_inline_c_missing no_pollerfd no_coredump cfg_new
-                strace strace_inject);
+                strace strace_inject lsof_pid);
         require Test::More;
         my @methods = grep(!/\W/, @Test::More::EXPORT);
         eval(join('', map { "*$_=\\&Test::More::$_;" } @methods));
@@ -951,6 +951,26 @@ sub test_httpd ($$;$$) {
         }
 };
 
+# TODO: support fstat(1) on OpenBSD, lsof already works on FreeBSD + Linux
+# don't use this for deleted file checks, we only check that on Linux atm
+# and we can readlink /proc/PID/fd/* directly
+sub lsof_pid ($;$) {
+        my ($pid, $rdr) = @_;
+        state $lsof = require_cmd('lsof', 1);
+        $lsof or skip 'lsof missing/broken', 1;
+        my @out = xqx([$lsof, '-p', $pid], undef, $rdr);
+        if ($?) {
+                undef $lsof;
+                skip "lsof -p PID broken \$?=$?", 1;
+        }
+        my @cols = split ' ', $out[0];
+        if (($cols[7] // '') eq 'NODE') { # normal lsof
+                @out;
+        } else { # busybox lsof ignores -p, so we DIY it
+                grep /\b$pid\b/, @out;
+        }
+}
+
 sub no_pollerfd ($) {
         my ($pid) = @_;
         my ($re, @cmd);
@@ -966,6 +986,7 @@ sub no_pollerfd ($) {
                 my @of = xqx(\@cmd, {}, {2 => \(my $e)});
                 my $err = $?;
                 skip "$bin broken? (\$?=$err) ($e)", 1 if $err;
+                @of = grep /\b$pid\b/, @of; # busybox lsof ignores -p
                 is(grep(/$re/, @of), 0, "no $re FDs") or diag explain(\@of);
         }
 }
diff --git a/t/ds-leak.t b/t/ds-leak.t
index 179997eb..f39985e0 100644
--- a/t/ds-leak.t
+++ b/t/ds-leak.t
@@ -29,11 +29,8 @@ if ('close-on-exec for epoll and kqueue') {
         is($l, undef, 'cloexec works and sleep(1) is running');
 
         SKIP: {
-                my $lsof = require_cmd('lsof', 1) or skip 'lsof missing', 1;
                 my $rdr = { 2 => \(my $null) };
-                my @of = grep(/$evfd_re/, xqx([$lsof, '-p', $pid], {}, $rdr));
-                my $err = $?;
-                skip "lsof broken ? (\$?=$err)", 1 if $err;
+                my @of = grep /$evfd_re/, lsof_pid $pid, $rdr;
                 is_deeply(\@of, [], 'no FDs leaked to subprocess');
         };
         if (defined $pid) {
diff --git a/t/httpd-corner.t b/t/httpd-corner.t
index da1c24b9..35c88600 100644
--- a/t/httpd-corner.t
+++ b/t/httpd-corner.t
@@ -639,30 +639,21 @@ SKIP: {
 };
 
 SKIP: {
-        skip 'only testing lsof(8) output on Linux', 1 if $^O ne 'linux';
-        my $lsof = require_cmd('lsof', 1) or skip 'no lsof in PATH', 1;
-        my $null_in = '';
-        my $rdr = { 2 => \(my $null_err), 0 => \$null_in };
-        my @lsof = xqx([$lsof, '-p', $td->{pid}], undef, $rdr);
-        my $d = [ grep(/\(deleted\)/, @lsof) ];
-        is_deeply($d, [], 'no lingering deleted inputs') or diag explain($d);
+        skip 'only testing /proc/PID/fd on Linux', 1 if $^O ne 'linux';
+        my $fd_dir = "/proc/$td->{pid}/fd";
+        -d $fd_dir or skip '/proc/$PID/fd missing', 1;
+        my @child = grep defined, map readlink, glob "$fd_dir/*";
+        my @d = grep /\(deleted\)/, @child;
+        is_deeply(\@d, [], 'no lingering deleted inputs') or diag explain(\@d);
 
         # filter out pipes inherited from the parent
-        my @this = xqx([$lsof, '-p', $$], undef, $rdr);
-        my $bad;
-        my $extract_inodes = sub {
-                map {;
-                        my @f = split(' ', $_);
-                        my $inode = $f[-2];
-                        $bad = $_ if $inode !~ /\A[0-9]+\z/;
-                        $inode => 1;
-                } grep (/\bpipe\b/, @_);
-        };
-        my %child = $extract_inodes->(@lsof);
+        my @this = grep defined, map readlink, glob "/proc/$$/fd/*";
+        my $extract_inodes = sub { map { $_ => 1 } grep /\bpipe\b/, @_ };
+        my %child = $extract_inodes->(@child);
         my %parent = $extract_inodes->(@this);
-        skip("inode not in expected format: $bad", 1) if defined($bad);
         delete @child{(keys %parent)};
-        is_deeply([], [keys %child], 'no extra pipes with -W0');
+        is_deeply([], [keys %child], 'no extra pipes with -W0') or
+                diag explain([child => \%child, parent => \%parent]);
 };
 
 # ensure compatibility with other PSGI servers
diff --git a/t/nntpd.t b/t/nntpd.t
index ffe0fd8c..0f3ef596 100644
--- a/t/nntpd.t
+++ b/t/nntpd.t
@@ -14,7 +14,6 @@ use PublicInbox::DS;
 my $version = $ENV{PI_TEST_VERSION} || 1;
 require_git('2.6') if $version == 2;
 use_ok 'PublicInbox::Msgmap';
-my $lsof = require_cmd('lsof', 1);
 my $fast_idle = eval { require Linux::Inotify2; 1 } //
                 eval { require IO::KQueue; 1 };
 
@@ -332,9 +331,7 @@ Date: Fri, 02 Oct 1993 00:00:00 +0000
                                 ($ENV{TEST_RUN_MODE} // 2)) {
                         skip 'Xapian.pm pre-loaded (by xt/check-run.t?)', 1;
                 }
-                $lsof or skip 'lsof missing', 1;
-                my @of = xqx([$lsof, '-p', $td->{pid}], undef, $noerr);
-                skip('lsof broken', 1) if (!scalar(@of) || $?);
+                my @of = lsof_pid $td->{pid}, $noerr;
                 my @xap = grep m!\bXapian\b!, @of;
                 is_deeply(\@xap, [], 'Xapian not loaded in nntpd') or
                         diag explain(\@of);
@@ -364,12 +361,13 @@ Date: Fri, 02 Oct 1993 00:00:00 +0000
                 tick($fast_idle ? 0.1 : 2.1);
                 $art = $n->article($ex->header('Message-ID'));
                 ok($art, 'new article retrieved after compact');
-                $lsof or skip 'lsof missing', 1;
-                ($^O =~ /\A(?:linux)\z/) or
+                $^O eq 'linux' or
                         skip "lsof /(deleted)/ check untested on $^O", 1;
-                my @lsof = xqx([$lsof, '-p', $td->{pid}], undef, $noerr);
-                my $d = [ grep(/\(deleted\)/, grep(!/batch-command\.err/, @lsof)) ];
-                is_deeply($d, [], 'no deleted files') or diag explain($d);
+                my $fd = "/proc/$td->{pid}/fd";
+                -d $fd or skip '/proc/PID/fd missing', 1;
+                my @of = map readlink, glob "$fd/*";
+                my @d = grep /\(deleted\)/, grep !/batch-command\.err/, @of;
+                is_deeply(\@d, [], 'no deleted files') or diag explain(\@d);
         };
         SKIP: { test_watch($tmpdir, $host_port, $group) };
         {
diff --git a/t/v2reindex.t b/t/v2reindex.t
index 406c0517..8c49e154 100644
--- a/t/v2reindex.t
+++ b/t/v2reindex.t
@@ -1,4 +1,4 @@
-# Copyright (C) 2018-2021 all contributors <meta@public-inbox.org>
+# Copyright (C) all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 use strict; use v5.10.1; use PublicInbox::TestCommon;
 use PublicInbox::Eml;
@@ -549,9 +549,8 @@ is($err, '', 'no errors from --xapian-only');
 undef $for_destroy;
 SKIP: {
         skip 'only testing lsof(8) output on Linux', 1 if $^O ne 'linux';
-        my $lsof = require_cmd('lsof', 1) or skip 'no lsof in PATH', 1;
         my $rdr = { 2 => \(my $null_err) };
-        my @d = grep(m!/xap[0-9]+/!, xqx([$lsof, '-p', $$], undef, $rdr));
+        my @d = grep m!/xap[0-9]+/!, lsof_pid $$, $rdr;
         is_deeply(\@d, [], 'no deleted index files') or diag explain(\@d);
 }
 done_testing();