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TCPd: code simplification & (most important) error management.

This commit is contained in:
Philippe Pittoli 2023-01-12 21:02:05 +01:00
parent 614e972b95
commit aca3f2183d

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@ -19,23 +19,16 @@ const print_eq = @import("./util.zig").print_eq;
const URI = @import("./util.zig").URI;
fn init_tcp_server(allocator: std.mem.Allocator, server: *net.StreamServer) !i32 {
var buffer: [1000]u8 = undefined;
var fbs = std.io.fixedBufferStream(&buffer);
var writer = fbs.writer();
var address = std.process.getEnvVarOwned(allocator, "ADDRESS") catch |err| switch(err) {
error.EnvironmentVariableNotFound => blk: {
print("no ADDRESS envvar: TCPd will listen on 127.0.0.1:9000\n", .{});
print ("no ADDRESS envvar: TCPd will listen on 127.0.0.1:9000\n", .{});
break :blk try allocator.dupe(u8, "127.0.0.1:9000");
},
else => { return err; },
};
defer allocator.free(address);
try writer.print("{s}", .{address});
var tcp_address = fbs.getWritten();
var iterator = std.mem.split(u8, tcp_address, ":");
var iterator = std.mem.split(u8, address, ":");
var real_tcp_address = iterator.first();
var real_tcp_port = try std.fmt.parseUnsigned(u16, iterator.rest(), 10);
@ -61,7 +54,7 @@ fn create_service() !void {
// SERVER SIDE: creating a service.
var service_name = std.process.getEnvVarOwned(allocator, "IPC_SERVICE_NAME") catch |err| switch(err) {
error.EnvironmentVariableNotFound => blk: {
print("no IPC_SERVICE_NAME envvar: TCPd will be named 'tcp'\n", .{});
print ("no IPC_SERVICE_NAME envvar: TCPd will be named 'tcp'\n", .{});
break :blk try allocator.dupe(u8, "tcp");
},
else => { return err; },
@ -100,10 +93,8 @@ fn create_service() !void {
// Quit on SIGHUP (kill -1).
try os.sigaction(os.SIG.HUP, &sa, null);
// TODO: create a TCP socket.
var server: net.StreamServer = undefined;
var serverfd = try init_tcp_server(allocator, &server);
// TODO: add the socket to the list of ctx FDs.
try ctx.add_external (serverfd);
var some_event: ipc.Event = undefined;
@ -113,57 +104,66 @@ fn create_service() !void {
some_event = try ctx.wait_event();
switch (some_event.t) {
.TIMER => {
print("\rTimer! ({})", .{count});
print ("\rTimer! ({})", .{count});
count += 1;
},
.CONNECTION => {
print("New connection: {} so far!\n", .{ctx.pollfd.items.len});
print ("New connection: {} so far!\n", .{ctx.pollfd.items.len});
},
.DISCONNECTION => {
print("User {} disconnected, {} remainaing.\n"
print ("User {} disconnected, {} remaining.\n"
, .{some_event.origin, ctx.pollfd.items.len});
},
.EXTERNAL => {
print("Message received from a non IPC socket.\n", .{});
print ("Message received from a non IPC socket.\n", .{});
var client = try server.accept(); // net.StreamServer.Connection
errdefer client.stream.close();
// Receiving a new client from the EXTERNAL socket.
// New client = new switch from a distant TCP connection to a
// local libipc service.
var buffer: [1000]u8 = undefined;
var buffer: [10000]u8 = undefined;
var size = try client.stream.read(&buffer);
print ("Asking to connect to service [{s}]\n", .{buffer[0..size]});
var servicefd = try ctx.connect_service (buffer[0..size]);
// Send a message to inform remote TCPd that the connection is established.
var service_to_contact = buffer[0..size];
print ("Ask to connect to service [{s}].\n", .{service_to_contact});
var servicefd = try ctx.connect_service (service_to_contact);
errdefer ctx.close_fd (servicefd) catch {};
print ("Send a message to inform remote TCPd that the connection is established.\n", .{});
_ = try client.stream.write("ok");
print("add current client as external connection (for now)\n", .{});
print ("Add current client as external connection (for now).\n", .{});
try ctx.add_external (client.stream.handle);
print ("Message sent, switching.\n", .{});
try ctx.add_switch(client.stream.handle, servicefd);
print ("DONE.\n", .{});
// Some protocols will require to change the default functions
// to read and to write on the client socket.
// Function to call: ctx.set_switch_callbacks(clientfd, infn, outfn);
},
.SWITCH_RX => {
print("Message has been received (SWITCH fd {}).\n", .{some_event.origin});
print ("Message has been received (SWITCH fd {}).\n", .{some_event.origin});
},
.SWITCH_TX => {
print("Message has been sent (SWITCH fd {}).\n", .{some_event.origin});
print ("Message has been sent (SWITCH fd {}).\n", .{some_event.origin});
},
.MESSAGE => {
print("Client asking for a service through TCPd.\n", .{});
print ("Client asking for a service through TCPd.\n", .{});
errdefer ctx.close (some_event.index) catch {};
if (some_event.m) |m| {
print("{}\n", .{m});
defer m.deinit(); // Do not forget to free the message payload.
print ("URI to work with is {s}\n", .{m.payload});
print ("URI to contact {s}\n", .{m.payload});
var uri = URI.read(m.payload);
print ("proto [{s}] address [{s}] path [{s}]\n"
, .{uri.protocol, uri.address, uri.path});
@ -171,33 +171,34 @@ fn create_service() !void {
var iterator = std.mem.split(u8, uri.address, ":");
var real_tcp_address = iterator.first();
var real_tcp_port = try std.fmt.parseUnsigned(u16, iterator.rest(), 10);
var socket_addr = try net.Address.parseIp(real_tcp_address, real_tcp_port);
var stream = try net.tcpConnectToAddress(socket_addr);
errdefer stream.close();
print("Writing URI PATH: {s}\n", .{uri.path});
print ("Writing URI PATH: {s}\n", .{uri.path});
_ = try stream.write(uri.path);
print("Writing URI PATH - written, waiting for the final 'ok'\n", .{});
var buffer: [1000]u8 = undefined;
print ("Writing URI PATH - written, waiting for the final 'ok'.\n", .{});
var buffer: [10000]u8 = undefined;
var size = try stream.read(&buffer);
if (! std.mem.eql(u8, buffer[0..size], "ok")) {
print("didn't receive 'ok', let's kill the connection\n", .{});
print ("didn't receive 'ok', let's kill the connection\n", .{});
stream.close();
try ctx.close_fd(some_event.origin);
try ctx.close(some_event.index);
continue;
}
print("final 'ok' received, sending 'ok' to IPCd\n", .{});
print ("Final 'ok' received, sending 'ok' to IPCd.\n", .{});
// Connection is established, inform IPCd.
var response = try Message.init(some_event.origin, allocator, "ok");
defer response.deinit();
try ctx.write(response);
print("add current client as external connection (for now)\n", .{});
print ("Add current client as external connection (for now).\n", .{});
try ctx.add_external (stream.handle);
print("Finally, add switching\n", .{});
// Let's switch the connections!
print ("Finally, add switching\n", .{});
try ctx.add_switch(some_event.origin, stream.handle);
// Could invoke ctx.set_switch_callbacks but TCP sockets are
// working pretty well with default functions.
@ -212,17 +213,17 @@ fn create_service() !void {
},
.TX => {
print("Message sent.\n", .{});
print ("Message sent.\n", .{});
},
.ERROR => {
print("A problem occured, event: {}, let's suicide\n", .{some_event});
print ("A problem occured, event: {}, let's suicide.\n", .{some_event});
break;
},
}
}
print("Goodbye\n", .{});
print ("Goodbye\n", .{});
}
pub fn main() !u8 {