[PATCH] pop3d: support fcntl locks on NetBSD and OpenBSD

[Eric Wong <e@80x24.org>]

MboxLock already supported it since it locked the whole file,
but POP3D requires more fine-grained locking at file offsets.

I wonder if "struct flock" is old enough for it to be the same
across all the BSDs...
---
 devel/sysdefs-list       | 23 +++++++++++++++++++++++
 lib/PublicInbox/POP3D.pm |  3 ++-
 t/pop3d.t                |  3 ++-
 3 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/devel/sysdefs-list b/devel/sysdefs-list
index 9764cc29..0356cbc1 100755
--- a/devel/sysdefs-list
+++ b/devel/sysdefs-list
@@ -33,14 +33,29 @@ __DATA__
 #  define _GNU_SOURCE
 #endif
 #include <signal.h>
+#include <stddef.h>
 #include <sys/syscall.h>
 #include <sys/ioctl.h>
 #ifdef __linux__
 #include <linux/fs.h>
 #endif
 #include <sys/types.h>
+#include <fcntl.h>
 #include <unistd.h>
 #include <stdio.h>
+#include <string.h>
+
+#define STRUCT_BEGIN(t) do { t x; printf("\n"#t" => %zu bytes\n", sizeof(x))
+#define STRUCT_END } while (0)
+
+// prints the struct field name, @offset, and signed/unsigned bit size
+#define PR_NUM(f) do { \
+	memset(&x.f, 0xff, sizeof(x.f)); \
+	printf("\t.%s @%zu %s%zu""\n", #f, \
+		offsetof(typeof(x),f), \
+		x.f > 0 ? "u" : "s", \
+		sizeof(x.f) * 8); \
+} while (0)
 
 #define D(x) printf("$" #x " = %ld;\n", (long)x)
 
@@ -70,5 +85,13 @@ int main(void)
 	D(SIGWINCH);
 	MAYBE _SC_NPROCESSORS_ONLN
 
+	STRUCT_BEGIN(struct flock);
+		PR_NUM(l_start);
+		PR_NUM(l_len);
+		PR_NUM(l_pid);
+		PR_NUM(l_type);
+		PR_NUM(l_whence);
+	STRUCT_END;
+
 	return 0;
 }
diff --git a/lib/PublicInbox/POP3D.pm b/lib/PublicInbox/POP3D.pm
index 3fc85efc..580a26d3 100644
--- a/lib/PublicInbox/POP3D.pm
+++ b/lib/PublicInbox/POP3D.pm
@@ -14,6 +14,7 @@ use PublicInbox::Syscall;
 use File::Temp 0.19 (); # 0.19 for ->newdir
 use Fcntl qw(F_SETLK F_UNLCK F_WRLCK SEEK_SET);
 my @FLOCK;
+# are all BSDs the same "struct flock"? tested Free+Net+Open...
 if ($^O eq 'linux' || $^O =~ /bsd/) {
 	require Config;
 	my $off_t;
@@ -27,7 +28,7 @@ if ($^O eq 'linux' || $^O =~ /bsd/) {
 		if ($^O eq 'linux') {
 			@FLOCK = ("ss\@8$off_t$off_t\@32",
 				qw(l_type l_whence l_start l_len));
-		} elsif ($^O =~ /bsd/) {
+		} elsif ($^O =~ /bsd/) { # @32 may be enough
 			@FLOCK = ("${off_t}${off_t}lss\@256",
 				qw(l_start l_len l_pid l_type l_whence));
 		}
diff --git a/t/pop3d.t b/t/pop3d.t
index dc52b0cf..95875105 100644
--- a/t/pop3d.t
+++ b/t/pop3d.t
@@ -14,7 +14,8 @@ unless (-r $key && -r $cert) {
 # Net::POP3 is part of the standard library, but distros may split it off...
 require_mods(qw(DBD::SQLite Net::POP3 IO::Socket::SSL));
 require_git('2.6'); # for v2
-require_mods(qw(File::FcntlLock)) if $^O !~ /\A(?:linux|freebsd)\z/;
+$^O =~ /\A(?:linux|(?:free|net|open)bsd)\z/ or
+	require_mods(qw(File::FcntlLock));
 use_ok 'IO::Socket::SSL';
 use_ok 'PublicInbox::TLS';
 my ($tmpdir, $for_destroy) = tmpdir();