libipc-examples/zig/src/ipcd.zig

227 lines
9.0 KiB
Zig

const std = @import("std");
const net = std.net;
const fmt = std.fmt;
const os = std.os;
const ipc = @import("ipc");
const hexdump = ipc.hexdump;
const Message = ipc.Message;
// Import send_fd this way in order to produce docs for exchange-fd functions.
const exchange_fd = ipc.exchangefd;
const send_fd = exchange_fd.send_fd;
const builtin = @import("builtin");
const native_os = builtin.target.os.tag;
const print = std.debug.print;
const testing = std.testing;
const print_eq = ipc.util.print_eq;
const URI = ipc.util.URI;
// Standard library is unecessary complex regarding networking.
// libipc drops it and uses plain old file descriptors instead.
// API should completely obfuscate the inner structures.
// Only libipc structures should be necessary to write any networking code,
// users should only work with Context and Message, mostly.
// QUESTION: should libipc use std.fs.path and not simple [] const u8?
fn create_service() !void {
const config = .{.safety = true};
var gpa = std.heap.GeneralPurposeAllocator(config){};
defer _ = gpa.deinit();
const allocator = gpa.allocator();
var ctx = try ipc.Context.init(allocator);
defer ctx.deinit(); // There. Can't leak. Isn't Zig wonderful?
// SERVER SIDE: creating a service.
_ = try ctx.server_init("ipc");
// signal handler, to quit when asked
const S = struct {
var should_quit: bool = false;
fn handler(sig: i32, info: *const os.siginfo_t, _: ?*const anyopaque) callconv(.C) void {
print ("A signal has been received: {}\n", .{sig});
// Check that we received the correct signal.
switch (native_os) {
.netbsd => {
if (sig != os.SIG.HUP or sig != info.info.signo)
return;
},
else => {
if (sig != os.SIG.HUP and sig != info.signo)
return;
},
}
should_quit = true;
}
};
var sa = os.Sigaction{
.handler = .{ .sigaction = &S.handler },
.mask = os.empty_sigset, // Do not mask any signal.
.flags = os.SA.SIGINFO,
};
// Quit on SIGHUP (kill -1).
try os.sigaction(os.SIG.HUP, &sa, null);
var some_event: ipc.Event = undefined;
ctx.timer = 1000; // 1 second
var count: u32 = 0;
while(! S.should_quit) {
some_event = try ctx.wait_event();
switch (some_event.t) {
.TIMER => {
print("\rTimer! ({})", .{count});
count += 1;
},
.CONNECTION => {
print("New connection: {} so far!\n", .{ctx.pollfd.items.len});
},
.DISCONNECTION => {
print("User {} disconnected, {} remainaing.\n"
, .{some_event.origin, ctx.pollfd.items.len});
},
.EXTERNAL => {
print("Message received from a non IPC socket.\n", .{});
print("NOT IMPLEMENTED, YET. It's a suicide, then.\n", .{});
break;
},
.SWITCH_RX => {
print("Message has been received (SWITCH).\n", .{});
print("NOT IMPLEMENTED, YET. It's a suicide, then.\n", .{});
break;
},
.SWITCH_TX => {
print("Message has been sent (SWITCH).\n", .{});
print("NOT IMPLEMENTED, YET. It's a suicide, then.\n", .{});
break;
},
.MESSAGE_RX => {
print("Client asking for a service through ipcd.\n", .{});
defer ctx.close_fd (some_event.origin) catch {};
if (some_event.m) |m| {
print("{}\n", .{m});
defer m.deinit(); // Do not forget to free the message payload.
// 1. split message
var iterator = std.mem.split(u8, m.payload, ";");
var service_to_contact = iterator.first();
// print("service to contact: {s}\n", .{service_to_contact});
var final_destination: ?[]const u8 = null;
// 2. find relevant part of the message
while (iterator.next()) |next| {
// print("next part: {s}\n", .{next});
var iterator2 = std.mem.split(u8, next, " ");
var sname = iterator2.first();
var target = iterator2.next();
if (target) |t| {
// print ("sname: {s} - target: {s}\n", .{sname, t});
if (std.mem.eql(u8, service_to_contact, sname)) {
final_destination = t;
}
}
else {
print("ERROR: no target in: {s}\n", .{next});
}
}
// 3. connect whether asked to and send a message
if (final_destination) |dest| {
print("Connecting to {s} (service requested: {s})\n"
, .{dest, service_to_contact});
var uri = URI.read(dest);
// 1. in case there is no URI
if (std.mem.eql(u8, uri.protocol, dest)) {
var newfd = try ctx.connect_service (dest);
send_fd (some_event.origin, "ok", newfd);
try ctx.close_fd (newfd);
}
else if (std.mem.eql(u8, uri.protocol, "unix")) {
var newfd = try ctx.connect_service (uri.address);
send_fd (some_event.origin, "ok", newfd);
try ctx.close_fd (newfd);
}
// 2. else, contact <protocol>d or directly the dest in case there is none.
else {
var servicefd = try ctx.connect_service (uri.protocol);
defer ctx.close_fd (servicefd) catch {};
// TODO: make a simple protocol between IPCd and <protocol>d
// NEED inform about the connection (success or fail)
// FIRST DRAFT:
// - IPCd: send a message containing the destination
// - PROTOCOLd: send "ok" to inform the connection is established
// - PROTOCOLd: send "no" in case there was an error
var message = try Message.init(servicefd, allocator, dest);
defer message.deinit();
try ctx.write(message);
var response_from_service = try ctx.read_fd(servicefd);
if (response_from_service) |r| {
defer r.deinit();
if (std.mem.eql(u8, r.payload, "ok")) {
// OK
// print("service has established the connection\n", .{});
send_fd (some_event.origin, "ok", servicefd);
}
else if (std.mem.eql(u8, r.payload, "ne")) {
// PROBLEM
print("service cannot establish the connection\n", .{});
// TODO
}
else {
print("service isn't working properly, its response is: {s}\n", .{r.payload});
// TODO
}
}
else {
// No message = should be handled as a disconnection.
print("No response from service: let's drop everything\n", .{});
}
}
}
}
else {
// There is a problem: ipcd was contacted without providing
// a message, meaning there is nothing to do. This should be
// explicitely warned about.
var response = try Message.init(some_event.origin
, allocator
, "lookup message without data");
defer response.deinit();
try ctx.write(response);
}
},
.MESSAGE_TX => {
print("Message sent.\n", .{});
},
.ERROR => {
print("A problem occured, event: {}, let's suicide\n", .{some_event});
break;
},
}
}
print("Goodbye\n", .{});
}
pub fn main() !u8 {
try create_service();
return 0;
}