Parse v6 address correctly, first working version

build.zig

@@ -20,8 +20,8 @@ pub fn build(b: *std.Build) void {
         .root_source_file = b.path("src/main.zig"),
         .target = target,
         .optimize = optimize,
+        .link_libc = true,
     });
-    exe.addIncludePath(.{ .path = "lib" });
 
     // This declares intent for the executable to be installed into the
     // standard location when the user invokes the "install" step (the default
@@ -58,7 +58,6 @@ pub fn build(b: *std.Build) void {
         .target = target,
         .optimize = optimize,
     });
-    sockets_unit_tests.addIncludePath(.{ .path = "lib" });
 
     const run_sockets_unit_tests = b.addRunArtifact(sockets_unit_tests);
     run_sockets_unit_tests.has_side_effects = true; // needed so tests aren't cached
@@ -70,7 +69,6 @@ pub fn build(b: *std.Build) void {
         .target = target,
         .optimize = optimize,
     });
-    process_unit_tests.addIncludePath(.{ .path = "lib" });
 
     const run_process_unit_tests = b.addRunArtifact(process_unit_tests);
     run_process_unit_tests.has_side_effects = true; // needed so tests aren't cached
@@ -79,8 +77,8 @@ pub fn build(b: *std.Build) void {
         .root_source_file = b.path("src/main.zig"),
         .target = target,
         .optimize = optimize,
+        .link_libc = true,
     });
-    exe_unit_tests.addIncludePath(.{ .path = "lib" });
 
     const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
 

src/main.zig

@@ -1,6 +1,11 @@
 const std = @import("std");
 const sockets = @import("sockets.zig");
 const process = @import("process.zig");
+const c = @cImport({
+    @cInclude("pwd.h");
+    @cInclude("arpa/inet.h");
+    @cInclude("signal.h");
+});
 
 pub const std_options = .{ .log_level = .info };
 
@@ -14,19 +19,124 @@ pub fn main() !void {
 
     const alloc = gpa.allocator();
 
-    const clog_sockets = try sockets.parse(alloc, null);
+    const pids = try print_clogs(alloc, port);
-    defer alloc.free(clog_sockets);
+    defer alloc.free(pids);
 
-    for (clog_sockets) |clog_socket| {
+    if (pids.len == 0) {
-        if (clog_socket.port == port) {
+        return;
-            const p = try process.find_by_inode(alloc, clog_socket.inode, null);
+    }
-            defer p.deinit();
+
-            switch (clog_socket.protocol_data) {
+    const kill_pids = try choose_kill();
-                .tcp_v4 => |v4| std.log.info("Found process {any} clogging address {any}", .{ p, v4.addr }),
+
-                .udp_v4 => |v4| std.log.info("Found process {any} clogging address {any}", .{ p, v4.addr }),
+    kill(&[_]std.posix.pid_t{
-                .tcp_v6 => |v6| std.log.info("Found process {any} clogging address {any}", .{ p, v6.addr }),
+        pids[kill_pids[0]],
-                .udp_v6 => |v6| std.log.info("Found process {any} clogging address {any}", .{ p, v6.addr }),
+    });
+}
+
+fn kill(pids: []const std.posix.pid_t) void {
+    for (pids) |pid| {
+        if (c.kill(pid, c.SIGTERM) == 0) {
+            // Wait briefly for process to exit
+            std.time.sleep(100000000); // 100ms
+
+            // Check if process still exists
+            if (c.kill(pid, 0) == 0) {
+                _ = c.kill(pid, c.SIGKILL); // now try with force
             }
         }
     }
 }
+
+fn choose_kill() ![]usize {
+    var stdin = std.io.getStdIn().reader();
+    var stdout = std.io.getStdOut().writer();
+
+    try stdout.writeAll("Kill? ");
+
+    var buf: [2]u8 = undefined;
+    _ = try stdin.readUntilDelimiter(&buf, '\n');
+
+    var kills = [_]usize{
+        (try std.fmt.parseInt(usize, buf[0..1], 10)) - 1,
+    };
+
+    return &kills;
+}
+
+fn print_clogs(alloc: std.mem.Allocator, port: u16) ![]std.posix.pid_t {
+    var writer = std.io.getStdOut().writer();
+    var pids = std.ArrayList(std.posix.pid_t).init(alloc);
+    defer pids.deinit(); // noop after re-owning memory at end
+
+    const clog_sockets = try sockets.parse(alloc, null);
+    defer alloc.free(clog_sockets);
+
+    var any: bool = false;
+    for (clog_sockets) |cs| {
+        if (cs.port == port) any = true;
+    }
+    if (!any) {
+        try writer.print("Port {d} looks unclogged\n", .{port});
+        return &[_]std.posix.pid_t{};
+    }
+
+    try writer.print("{s: <3}{s: <10} {s: <30} {s: <12} {s: <15} {s: <10} {s: <6} {s: <5}\n", .{ "#", "Command", "Path", "Protocol", "Address", "User", "Inode", "Port" });
+    var idx: usize = 1;
+
+    for (clog_sockets) |cs| {
+        if (cs.port == port) {
+            const clogs = try process.find_by_inode(alloc, cs.inode, null);
+            defer clogs.deinit();
+
+            const user = c.getpwuid(cs.uid);
+
+            for (clogs.items) |clog| {
+                switch (cs.protocol_data) {
+                    // zig fmt: off
+                    .tcp_v4 => |proto| {
+                        var addr: [c.INET_ADDRSTRLEN:0]u8 = undefined;
+                        _ = c.inet_ntop(c.AF_INET, &proto.addr, &addr, c.INET_ADDRSTRLEN);
+                        try writer.print("{d: <3}{s: <10} {s: <30} {s: <12} {s: <15} {s: <10} {d: <6} {d: <5}\n", .{
+                            idx,
+                            clog.comm[0..@min(10, clog.comm.len)], clog.exe[0..@min(30, clog.exe.len)],
+                            "TCP/IPv4", std.mem.sliceTo(&addr, 0),
+                            user.*.pw_name, cs.inode, cs.port });
+                    },
+                    .tcp_v6 => |proto| {
+                        var addr: [c.INET6_ADDRSTRLEN:0]u8 = undefined;
+                        _ = c.inet_ntop(c.AF_INET6, &proto.addr, &addr, c.INET6_ADDRSTRLEN);
+                        try writer.print("{d: <3}{s: <10} {s: <30} {s: <12} {s: <15} {s: <10} {d: <6} {d: <5}\n", .{
+                            idx,
+                            clog.comm[0..@min(10, clog.comm.len)], clog.exe[0..@min(30, clog.exe.len)],
+                            "TCP/IPv6", std.mem.sliceTo(&addr, 0),
+                            user.*.pw_name, cs.inode, cs.port });
+                    },
+                    .udp_v4 => |proto| {
+                        var addr: [c.INET_ADDRSTRLEN:0]u8 = undefined;
+                        _ = c.inet_ntop(c.AF_INET, &proto.addr, &addr, c.INET_ADDRSTRLEN);
+                        try writer.print("{d: <3}{s: <10} {s: <30} {s: <12} {s: <15} {s: <10} {d: <6} {d: <5}\n", .{
+                            idx,
+                            clog.comm[0..@min(10, clog.comm.len)], clog.exe[0..@min(30, clog.exe.len)],
+                            "UDP/IPv4", std.mem.sliceTo(&addr, 0),
+                            user.*.pw_name, cs.inode, cs.port });
+                    },
+                    .udp_v6 => |proto| {
+                        var addr: [c.INET6_ADDRSTRLEN:0]u8 = undefined;
+                        _ = c.inet_ntop(c.AF_INET6, &proto.addr, &addr, c.INET6_ADDRSTRLEN);
+                        try writer.print("{d: <3}{s: <10} {s: <30} {s: <12} {s: <15} {s: <10} {d: <6} {d: <5}\n", .{
+                            idx,
+                            clog.comm[0..@min(10, clog.comm.len)], clog.exe[0..@min(30, clog.exe.len)],
+                            "UDP/IPv6", std.mem.sliceTo(&addr, 0),
+                            user.*.pw_name, cs.inode, cs.port });
+                    },
+                    // zig fmt: on
+                }
+
+                try pids.append(clog.pid);
+                idx += 1;
+            }
+        }
+    }
+
+    return pids.toOwnedSlice();
+}

src/sockets.zig

@@ -124,15 +124,38 @@ fn parse_internal(path: []const u8, protocol: Protocol, buf: *std.ArrayList(Clog
             .uid = try std.fmt.parseInt(std.posix.uid_t, uid, 10),
             .protocol_data = switch (protocol) {
                 .tcp_v4 => .{ .tcp_v4 = .{ .addr = try std.fmt.parseInt(u32, local_address[0..8], 16) } },
-                .tcp_v6 => .{ .tcp_v6 = .{ .addr = try std.fmt.parseInt(u128, local_address[0..32], 16) } },
+                .tcp_v6 => .{ .tcp_v6 = .{ .addr = try parse_v6_address(local_address[0..32]) } },
 
                 .udp_v4 => .{ .udp_v4 = .{ .addr = try std.fmt.parseInt(u32, local_address[0..8], 16) } },
-                .udp_v6 => .{ .udp_v6 = .{ .addr = try std.fmt.parseInt(u128, local_address[0..32], 16) } },
+                .udp_v6 => .{ .udp_v6 = .{ .addr = try parse_v6_address(local_address[0..32]) } },
             },
         });
     }
 }
 
+// v6 addresses in /proc/net are not actually one big number, but an array of 4
+// 32-bit (4 byte) numbers, each in base-16 little-endian (or just host byte order
+// probably)
+fn parse_v6_address(data: []const u8) !u128 {
+    var buf: [4]u32 = undefined;
+
+    buf[0] = try std.fmt.parseInt(u32, data[0..8], 16);
+    buf[1] = try std.fmt.parseInt(u32, data[8..16], 16);
+    buf[2] = try std.fmt.parseInt(u32, data[16..24], 16);
+    buf[3] = try std.fmt.parseInt(u32, data[24..32], 16);
+
+    // now do the fun stuff, just re-interpret the array as u128
+    return std.mem.bytesToValue(u128, &buf);
+}
+
+test "parse_v6" {
+    std.testing.log_level = .info;
+
+    const data = "00000000000000000000000001000000";
+    const r = try parse_v6_address(data);
+    std.log.info("Got {d}", .{r});
+}
+
 test "parse" {
     var alloc = std.testing.allocator;