From 02c164882396f4f8b3dfff6ea90e8d19c8b869bf Mon Sep 17 00:00:00 2001
From: "Jeffrey C. Ollie" <jeff@ocjtech.us>
Date: Sat, 22 Mar 2025 12:03:01 -0500
Subject: [PATCH] first
---
.gitignore | 4 ++
build.zig | 34 +++++++++++
build.zig.zon | 14 +++++
src/PipeReader.zig | 56 +++++++++++++++++
src/UnixSocketReader.zig | 129 +++++++++++++++++++++++++++++++++++++++
src/main.zig | 85 ++++++++++++++++++++++++++
6 files changed, 322 insertions(+)
create mode 100644 .gitignore
create mode 100644 build.zig
create mode 100644 build.zig.zon
create mode 100644 src/PipeReader.zig
create mode 100644 src/UnixSocketReader.zig
create mode 100644 src/main.zig
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..a4aa3da
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+/zig-out
+/.zig-cache
+/result*
+
diff --git a/build.zig b/build.zig
new file mode 100644
index 0000000..bae698b
--- /dev/null
+++ b/build.zig
@@ -0,0 +1,34 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+ const target = b.standardTargetOptions(.{});
+ const optimize = b.standardOptimizeOption(.{});
+
+ // We will also create a module for our other entry point, 'main.zig'.
+ const exe_mod = b.createModule(.{
+ .root_source_file = b.path("src/main.zig"),
+ .target = target,
+ .optimize = optimize,
+ });
+
+ const exe = b.addExecutable(.{
+ .name = "zig_logging_wrapper",
+ .root_module = exe_mod,
+ });
+ b.installArtifact(exe);
+ const run_cmd = b.addRunArtifact(exe);
+ run_cmd.step.dependOn(b.getInstallStep());
+ if (b.args) |args| {
+ run_cmd.addArgs(args);
+ }
+ const run_step = b.step("run", "Run the app");
+ run_step.dependOn(&run_cmd.step);
+
+ const exe_unit_tests = b.addTest(.{
+ .root_module = exe_mod,
+ });
+
+ const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
+ const test_step = b.step("test", "Run unit tests");
+ test_step.dependOn(&run_exe_unit_tests.step);
+}
diff --git a/build.zig.zon b/build.zig.zon
new file mode 100644
index 0000000..c80576f
--- /dev/null
+++ b/build.zig.zon
@@ -0,0 +1,14 @@
+.{
+ .name = .zig_logging_wrapper,
+
+ .version = "0.0.0",
+ .fingerprint = 0x259c6307f5768bcf, // Changing this has security and trust implications.
+ .minimum_zig_version = "0.14.0",
+ .dependencies = .{},
+
+ .paths = .{
+ "build.zig",
+ "build.zig.zon",
+ "src",
+ },
+}
diff --git a/src/PipeReader.zig b/src/PipeReader.zig
new file mode 100644
index 0000000..8c0ee0d
--- /dev/null
+++ b/src/PipeReader.zig
@@ -0,0 +1,56 @@
+const PipeReader = @This();
+
+const std = @import("std");
+
+const log = std.log.scoped(.pipe_reader);
+
+spawn_failed: *bool,
+exe: *std.process.Child,
+pipe: enum { stdout, stderr },
+sem: std.Thread.Semaphore = .{},
+thread: std.Thread = undefined,
+
+pub fn spawn(self: *PipeReader) !void {
+ self.thread = try std.Thread.spawn(.{}, reader, .{self});
+}
+
+pub fn wait(self: *PipeReader) void {
+ self.sem.wait();
+}
+
+pub fn join(self: *PipeReader) void {
+ self.thread.join();
+}
+
+fn reader(self: *PipeReader) void {
+ const fd: std.fs.File = fd: {
+ defer self.sem.post();
+ while (!self.spawn_failed.*) {
+ switch (self.pipe) {
+ .stdout => if (self.exe.stdout) |fd| break :fd fd,
+ .stderr => if (self.exe.stderr) |fd| break :fd fd,
+ }
+ std.time.sleep(10 * std.time.ns_per_ms);
+ }
+ self.sem.post();
+ return;
+ };
+
+ const rdr = fd.reader();
+
+ while (true) {
+ var buf: [2048]u8 = undefined;
+ const line = rdr.readUntilDelimiter(&buf, '\n') catch |err| switch (err) {
+ error.EndOfStream => return,
+ error.NotOpenForReading => return,
+ else => {
+ log.err("{s}: {}", .{ @tagName(self.pipe), err });
+
+ return;
+ },
+ };
+ const ts = std.time.nanoTimestamp();
+ if (line.len == 0) break;
+ log.info("{s}: {d} {s}", .{ @tagName(self.pipe), ts, line });
+ }
+}
diff --git a/src/UnixSocketReader.zig b/src/UnixSocketReader.zig
new file mode 100644
index 0000000..d4ed6e8
--- /dev/null
+++ b/src/UnixSocketReader.zig
@@ -0,0 +1,129 @@
+const UnixSocketReader = @This();
+
+const std = @import("std");
+
+const log = std.log.scoped(.socket_reader);
+
+sock: std.posix.socket_t = undefined,
+thread: std.Thread = undefined,
+
+pub fn init(self: *UnixSocketReader) !void {
+ const path: []const u8 = "/tmp/wrapper";
+
+ var dir = try std.fs.openDirAbsolute(std.fs.path.dirname(path) orelse return error.BadPath, .{});
+ defer dir.close();
+ dir.deleteFile(std.fs.path.basename(path)) catch {};
+
+ var addr = std.mem.zeroes(std.posix.sockaddr.un);
+ addr.family = std.posix.AF.UNIX;
+ @memcpy(addr.path[0..path.len], path);
+
+ self.sock = try std.posix.socket(std.posix.AF.UNIX, std.posix.SOCK.DGRAM, 0);
+ try std.posix.bind(self.sock, @ptrCast(&addr), @sizeOf(std.posix.sockaddr.un));
+}
+
+pub fn spawn(self: *UnixSocketReader) !void {
+ self.thread = try std.Thread.spawn(.{}, reader, .{self});
+ self.thread.detach();
+}
+
+const Severity = enum(u8) {
+ EMERG = 0,
+ ALERT = 1,
+ CRIT = 2,
+ ERR = 3,
+ WARNING = 4,
+ NOTICE = 5,
+ INFO = 6,
+ DEBUG = 7,
+};
+
+const Facility = enum(u8) {
+ KERN = (0 << 3),
+ USER = (1 << 3),
+ MAIL = (2 << 3),
+ DAEMON = (3 << 3),
+ AUTH = (4 << 3),
+ SYSLOG = (5 << 3),
+ LPR = (6 << 3),
+ NEWS = (7 << 3),
+ UUCP = (8 << 3),
+ CRON = (9 << 3),
+ AUTHPRIV = (10 << 3),
+ FTP = (11 << 3),
+ NTP = (12 << 3),
+ AUDIT = (13 << 3),
+ ALERT = (14 << 3),
+ CLOCK = (15 << 3),
+ LOCAL0 = (16 << 3),
+ LOCAL1 = (17 << 3),
+ LOCAL2 = (18 << 3),
+ LOCAL3 = (19 << 3),
+ LOCAL4 = (20 << 3),
+ LOCAL5 = (21 << 3),
+ LOCAL6 = (22 << 3),
+ LOCAL7 = (23 << 3),
+};
+
+pub fn reader(self: *UnixSocketReader) void {
+ while (true) {
+ var buf: [4096]u8 = undefined;
+ var addr: std.posix.sockaddr = undefined;
+ var addrlen: std.posix.socklen_t = @sizeOf(std.posix.sockaddr);
+ const len = std.posix.recvfrom(self.sock, &buf, 0, &addr, &addrlen) catch |err| {
+ log.info("socket reader: {}", .{err});
+ return;
+ };
+ const line = buf[0..len];
+ syslog: {
+ if (line.len < 3) {
+ log.warn("data too short to be syslog", .{});
+ break :syslog;
+ }
+ const pri_start_char = std.mem.indexOfScalar(u8, line, '<') orelse {
+ log.warn("syslog: can't find '<'", .{});
+ break :syslog;
+ };
+ if (pri_start_char != 0) {
+ log.warn("syslog does not start with '<'", .{});
+ break :syslog;
+ }
+ const pri_end_char = std.mem.indexOfScalarPos(u8, line, 1, '>') orelse {
+ log.warn("syslog: can't find '>'", .{});
+ break :syslog;
+ };
+ const pri = line[pri_start_char + 1 .. pri_end_char];
+ if (pri.len < 1) {
+ log.warn("pri is too short", .{});
+ break :syslog;
+ }
+ if (pri.len > 3) {
+ log.warn("pri is too long", .{});
+ break :syslog;
+ }
+ for (pri) |ch| if (!std.ascii.isDigit(ch)) {
+ log.warn("invalid digit in pri", .{});
+ break :syslog;
+ };
+ const prival = std.fmt.parseUnsigned(u8, pri, 10) catch |err| {
+ log.warn("unable to convert pri to an integer: {}", .{err});
+ break :syslog;
+ };
+ if (prival > 191) {
+ log.warn("prival out of range", .{});
+ break :syslog;
+ }
+ log.info("pri: \'{s}\'", .{pri});
+ const severity = std.meta.intToEnum(Severity, prival & 0b00000111) catch {
+ log.warn("unable to convert severity", .{});
+ break :syslog;
+ };
+ const facility = std.meta.intToEnum(Facility, prival & 0b11111000) catch {
+ log.warn("unable to convert facility", .{});
+ break :syslog;
+ };
+ log.info("severity: {s} facility: {s}", .{ @tagName(severity), @tagName(facility) });
+ }
+ log.info("{s}", .{line});
+ }
+}
diff --git a/src/main.zig b/src/main.zig
new file mode 100644
index 0000000..eaf2cad
--- /dev/null
+++ b/src/main.zig
@@ -0,0 +1,85 @@
+const std = @import("std");
+const builtin = @import("builtin");
+
+const log = std.log.scoped(.wrapper);
+
+const PipeReader = @import("PipeReader.zig");
+const SocketReader = @import("SocketReader.zig");
+
+var debug_allocator: std.heap.DebugAllocator(.{}) = .init;
+
+pub fn main() !void {
+ const alloc, const is_debug = switch (builtin.mode) {
+ .Debug, .ReleaseSafe => .{ debug_allocator.allocator(), true },
+ .ReleaseFast, .ReleaseSmall => .{ std.heap.smp_allocator, false },
+ };
+ defer if (is_debug) {
+ _ = debug_allocator.deinit();
+ };
+
+ var socket: SocketReader = .{};
+ try socket.init();
+ try socket.spawn();
+
+ var exe = std.process.Child.init(
+ &.{
+ "logger",
+ "--stderr",
+ "--unix=/tmp/wrapper",
+ "hello",
+ },
+ alloc,
+ );
+
+ exe.stdin_behavior = .Ignore;
+ exe.stdout_behavior = .Pipe;
+ exe.stderr_behavior = .Pipe;
+
+ var spawn_failed: bool = false;
+
+ var stdout: PipeReader = .{
+ .spawn_failed = &spawn_failed,
+ .exe = &exe,
+ .pipe = .stdout,
+ };
+ try stdout.spawn();
+ defer stdout.join();
+
+ var stderr: PipeReader = .{
+ .spawn_failed = &spawn_failed,
+ .exe = &exe,
+ .pipe = .stderr,
+ };
+ try stderr.spawn();
+ defer stderr.join();
+
+ exe.spawn() catch |err| {
+ log.err("err: {}", .{err});
+ spawn_failed = true;
+ return;
+ };
+
+ stdout.wait();
+ stderr.wait();
+
+ const rc = try exe.wait();
+
+ switch (rc) {
+ .Exited => |code| {
+ if (code != 0) {
+ log.warn("exited with error code {d}", .{code});
+ }
+ },
+ .Signal => |signal| {
+ log.warn("terminated with signal {}", .{signal});
+ },
+ .Stopped => |signal| {
+ log.warn("stopped with signal {}", .{signal});
+ },
+ .Unknown => |code| {
+ log.warn("unknown error {}", .{code});
+ },
+ }
+
+ log.info("finished!", .{});
+}