nc: Add -p option

With this change we support the well-known and shorter way to
create a listener on all interfaces:

`nc -lvp 1337`

instead of:

`nc -lv 0.0.0.0 1337`
This commit is contained in:
Fabian Dellwing 2023-04-18 08:07:27 +02:00 committed by Andrew Kaster
parent eff3f52bda
commit 7cfa108fad
2 changed files with 26 additions and 4 deletions

View file

@ -5,7 +5,7 @@ nc
## Synopsis
```sh
$ nc [--length ] [--listen] [-N] [--udp] [--verbose] <target> <port>
$ nc [--length ] [--listen] [-N] [--udp] [-p port] [--verbose] [target] [port]
```
## Description
@ -18,6 +18,7 @@ Network cat: Connect to network sockets as if it were a file.
* `-l`, `--listen`: Listen instead of connecting
* `-N`: Close connection after reading stdin to the end
* `-u`, `--udp`: UDP mode
* `-p port`: Local port for remote connections
* `-v`, `--verbose`: Log everything that's happening
## Arguments

View file

@ -1,5 +1,6 @@
/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2023, Fabian Dellwing <fabian@dellwing.net>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
@ -51,6 +52,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
bool udp_mode = false;
DeprecatedString target;
int port = 0;
int local_port = 0;
int maximum_tcp_receive_buffer_size_input = -1;
Core::ArgsParser args_parser;
@ -59,9 +61,10 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
args_parser.add_option(should_listen, "Listen instead of connecting", "listen", 'l');
args_parser.add_option(should_close, "Close connection after reading stdin to the end", nullptr, 'N');
args_parser.add_option(udp_mode, "UDP mode", "udp", 'u');
args_parser.add_option(local_port, "Local port for remote connections", nullptr, 'p', "port");
args_parser.add_option(verbose, "Log everything that's happening", "verbose", 'v');
args_parser.add_positional_argument(target, "Address to listen on, or the address or hostname to connect to", "target");
args_parser.add_positional_argument(port, "Port to connect to or listen on", "port");
args_parser.add_positional_argument(target, "Address to listen on, or the address or hostname to connect to", "target", Core::ArgsParser::Required::No);
args_parser.add_positional_argument(port, "Port to connect to or listen on", "port", Core::ArgsParser::Required::No);
args_parser.parse(arguments);
if (udp_mode) {
@ -90,11 +93,22 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
int listen_fd = -1;
if (should_listen) {
if ((!target.is_empty() && local_port > 0) || (!target.is_empty() && port == 0)) {
args_parser.print_usage(stderr, arguments.strings[0]);
return 1;
}
listen_fd = TRY(Core::System::socket(AF_INET, SOCK_STREAM, 0));
sockaddr_in sa {};
sa.sin_family = AF_INET;
sa.sin_port = htons(port);
if (local_port > 0) {
sa.sin_port = htons(local_port);
} else if (port > 0) {
sa.sin_port = htons(port);
}
sa.sin_addr.s_addr = htonl(INADDR_ANY);
if (!target.is_empty()) {
if (inet_pton(AF_INET, target.characters(), &sa.sin_addr) <= 0) {
@ -117,6 +131,11 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
warnln("waiting for a connection on {}:{}", inet_ntop(sin.sin_family, &sin.sin_addr, addr_str, sizeof(addr_str)), ntohs(sin.sin_port));
} else {
if (target.is_empty() || port == 0) {
args_parser.print_usage(stderr, arguments.strings[0]);
return 1;
}
fd = TRY(Core::System::socket(AF_INET, SOCK_STREAM, 0));
struct timeval timeout {
@ -136,6 +155,8 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
dst_addr.sin_port = htons(port);
dst_addr.sin_addr.s_addr = *(in_addr_t const*)hostent->h_addr_list[0];
// FIXME: Actually use the local_port for the outgoing connection once we have a working implementation of bind and connect
if (verbose) {
char addr_str[INET_ADDRSTRLEN];
warnln("connecting to {}:{}", inet_ntop(dst_addr.sin_family, &dst_addr.sin_addr, addr_str, sizeof(addr_str)), ntohs(dst_addr.sin_port));