networking/nc.c - codeaurora/busybox - Gitiles

 /* vi: set sw=4 ts=4: */
 /* nc: mini-netcat - built from the ground up for LRP
  *
  * Copyright (C) 1998, 1999  Charles P. Wright
  * Copyright (C) 1998  Dave Cinege
  *
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 //config:config NC
 //config:	bool "nc"
 //config:	default y
 //config:	help
 //config:	  A simple Unix utility which reads and writes data across network
 //config:	  connections.
 //config:
 //config:config NC_SERVER
 //config:	bool "Netcat server options (-l)"
 //config:	default y
 //config:	depends on NC
 //config:	help
 //config:	  Allow netcat to act as a server.
 //config:
 //config:config NC_EXTRA
 //config:	bool "Netcat extensions (-eiw and -f FILE)"
 //config:	default y
 //config:	depends on NC
 //config:	help
 //config:	  Add -e (support for executing the rest of the command line after
 //config:	  making or receiving a successful connection), -i (delay interval for
 //config:	  lines sent), -w (timeout for initial connection).
 //config:
 //config:config NC_110_COMPAT
 //config:	bool "Netcat 1.10 compatibility (+2.5k)"
 //config:	default n  # off specially for Rob
 //config:	depends on NC
 //config:	help
 //config:	  This option makes nc closely follow original nc-1.10.
 //config:	  The code is about 2.5k bigger. It enables
 //config:	  -s ADDR, -n, -u, -v, -o FILE, -z options, but loses
 //config:	  busybox-specific extensions: -f FILE.

 //applet:IF_NC(APPLET(nc, BB_DIR_USR_BIN, BB_SUID_DROP))

 //kbuild:lib-$(CONFIG_NC) += nc.o

 #include "libbb.h"
 #include "common_bufsiz.h"
 #if ENABLE_NC_110_COMPAT
 # include "nc_bloaty.c"
 #else

 //usage:#if !ENABLE_NC_110_COMPAT
 //usage:
 //usage:#if ENABLE_NC_SERVER || ENABLE_NC_EXTRA
 //usage:#define NC_OPTIONS_STR "\n"
 //usage:#else
 //usage:#define NC_OPTIONS_STR
 //usage:#endif
 //usage:
 //usage:#define nc_trivial_usage
 //usage:	IF_NC_EXTRA("[-iN] [-wN] ")IF_NC_SERVER("[-l] [-p PORT] ")
 //usage:       "["IF_NC_EXTRA("-f FILE|")"IPADDR PORT]"IF_NC_EXTRA(" [-e PROG]")
 //usage:#define nc_full_usage "\n\n"
 //usage:       "Open a pipe to IP:PORT" IF_NC_EXTRA(" or FILE")
 //usage:	NC_OPTIONS_STR
 //usage:	IF_NC_SERVER(
 //usage:     "\n	-l	Listen mode, for inbound connects"
 //usage:	IF_NC_EXTRA(
 //usage:     "\n		(use -ll with -e for persistent server)"
 //usage:	)
 //usage:     "\n	-p PORT	Local port"
 //usage:	)
 //usage:	IF_NC_EXTRA(
 //usage:     "\n	-w SEC	Connect timeout"
 //usage:     "\n	-i SEC	Delay interval for lines sent"
 //usage:     "\n	-f FILE	Use file (ala /dev/ttyS0) instead of network"
 //usage:     "\n	-e PROG	Run PROG after connect"
 //usage:	)
 //usage:
 //usage:#define nc_notes_usage ""
 //usage:	IF_NC_EXTRA(
 //usage:       "To use netcat as a terminal emulator on a serial port:\n\n"
 //usage:       "$ stty 115200 -F /dev/ttyS0\n"
 //usage:       "$ stty raw -echo -ctlecho && nc -f /dev/ttyS0\n"
 //usage:	)
 //usage:
 //usage:#define nc_example_usage
 //usage:       "$ nc foobar.somedomain.com 25\n"
 //usage:       "220 foobar ESMTP Exim 3.12 #1 Sat, 15 Apr 2000 00:03:02 -0600\n"
 //usage:       "help\n"
 //usage:       "214-Commands supported:\n"
 //usage:       "214-    HELO EHLO MAIL RCPT DATA AUTH\n"
 //usage:       "214     NOOP QUIT RSET HELP\n"
 //usage:       "quit\n"
 //usage:       "221 foobar closing connection\n"
 //usage:
 //usage:#endif

 /* Lots of small differences in features
  * when compared to "standard" nc
  */

 static void timeout(int signum UNUSED_PARAM)
 {
 	bb_error_msg_and_die("timed out");
 }

 int nc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int nc_main(int argc, char **argv)
 {
 	/* sfd sits _here_ only because of "repeat" option (-l -l). */
 	int sfd = sfd; /* for gcc */
 	int cfd = 0;
 	unsigned lport = 0;
 	IF_NOT_NC_SERVER(const) unsigned do_listen = 0;
 	IF_NOT_NC_EXTRA (const) unsigned wsecs = 0;
 	IF_NOT_NC_EXTRA (const) unsigned delay = 0;
 	IF_NOT_NC_EXTRA (const int execparam = 0;)
 	IF_NC_EXTRA     (char **execparam = NULL;)
 	struct pollfd pfds[2];
 	int opt; /* must be signed (getopt returns -1) */

 	if (ENABLE_NC_SERVER || ENABLE_NC_EXTRA) {
 		/* getopt32 is _almost_ usable:
 		** it cannot handle "... -e PROG -prog-opt" */
 		while ((opt = getopt(argc, argv,
 			"" IF_NC_SERVER("lp:") IF_NC_EXTRA("w:i:f:e:") )) > 0
 		) {
 			if (ENABLE_NC_SERVER && opt == 'l')
 				IF_NC_SERVER(do_listen++);
 			else if (ENABLE_NC_SERVER && opt == 'p')
 				IF_NC_SERVER(lport = bb_lookup_port(optarg, "tcp", 0));
 			else if (ENABLE_NC_EXTRA && opt == 'w')
 				IF_NC_EXTRA( wsecs = xatou(optarg));
 			else if (ENABLE_NC_EXTRA && opt == 'i')
 				IF_NC_EXTRA( delay = xatou(optarg));
 			else if (ENABLE_NC_EXTRA && opt == 'f')
 				IF_NC_EXTRA( cfd = xopen(optarg, O_RDWR));
 			else if (ENABLE_NC_EXTRA && opt == 'e' && optind <= argc) {
 				/* We cannot just 'break'. We should let getopt finish.
 				** Or else we won't be able to find where
 				** 'host' and 'port' params are
 				** (think "nc -w 60 host port -e PROG"). */
 				IF_NC_EXTRA(
 					char **p;
 					// +2: one for progname (optarg) and one for NULL
 					execparam = xzalloc(sizeof(char*) * (argc - optind + 2));
 					p = execparam;
 					*p++ = optarg;
 					while (optind < argc) {
 						*p++ = argv[optind++];
 					}
 				)
 				/* optind points to argv[argc] (NULL) now.
 				** FIXME: we assume that getopt will not count options
 				** possibly present on "-e PROG ARGS" and will not
 				** include them into final value of optind
 				** which is to be used ...  */
 			} else bb_show_usage();
 		}
 		argv += optind; /* ... here! */
 		argc -= optind;
 		// -l and -f don't mix
 		if (do_listen && cfd) bb_show_usage();
 		// File mode needs need zero arguments, listen mode needs zero or one,
 		// client mode needs one or two
 		if (cfd) {
 			if (argc) bb_show_usage();
 		} else if (do_listen) {
 			if (argc > 1) bb_show_usage();
 		} else {
 			if (!argc || argc > 2) bb_show_usage();
 		}
 	} else {
 		if (argc != 3) bb_show_usage();
 		argc--;
 		argv++;
 	}

 	if (wsecs) {
 		signal(SIGALRM, timeout);
 		alarm(wsecs);
 	}

 	if (!cfd) {
 		if (do_listen) {
 			sfd = create_and_bind_stream_or_die(argv[0], lport);
 			xlisten(sfd, do_listen); /* can be > 1 */
 #if 0  /* nc-1.10 does not do this (without -v) */
 			/* If we didn't specify a port number,
 			 * query and print it after listen() */
 			if (!lport) {
 				len_and_sockaddr lsa;
 				lsa.len = LSA_SIZEOF_SA;
 				getsockname(sfd, &lsa.u.sa, &lsa.len);
 				lport = get_nport(&lsa.u.sa);
 				fdprintf(2, "%d\n", ntohs(lport));
 			}
 #endif
 			close_on_exec_on(sfd);
  accept_again:
 			cfd = accept(sfd, NULL, 0);
 			if (cfd < 0)
 				bb_perror_msg_and_die("accept");
 			if (!execparam)
 				close(sfd);
 		} else {
 			cfd = create_and_connect_stream_or_die(argv[0],
 				argv[1] ? bb_lookup_port(argv[1], "tcp", 0) : 0);
 		}
 	}

 	if (wsecs) {
 		alarm(0);
 		/* Non-ignored signals revert to SIG_DFL on exec anyway */
 		/*signal(SIGALRM, SIG_DFL);*/
 	}

 	/* -e given? */
 	if (execparam) {
 		pid_t pid;
 		/* With more than one -l, repeatedly act as server */
 		if (do_listen > 1 && (pid = xvfork()) != 0) {
 			/* parent */
 			/* prevent zombies */
 			signal(SIGCHLD, SIG_IGN);
 			close(cfd);
 			goto accept_again;
 		}
 		/* child, or main thread if only one -l */
 		xmove_fd(cfd, 0);
 		xdup2(0, 1);
 		/*xdup2(0, 2); - original nc 1.10 does this, we don't */
 		IF_NC_EXTRA(BB_EXECVP(execparam[0], execparam);)
 		IF_NC_EXTRA(bb_perror_msg_and_die("can't execute '%s'", execparam[0]);)
 	}

 	/* loop copying stdin to cfd, and cfd to stdout */

 	pfds[0].fd = STDIN_FILENO;
 	pfds[0].events = POLLIN;
 	pfds[1].fd = cfd;
 	pfds[1].events = POLLIN;

 #define iobuf bb_common_bufsiz1
 	setup_common_bufsiz();
 	for (;;) {
 		int fdidx;
 		int ofd;
 		int nread;

 		if (safe_poll(pfds, 2, -1) < 0)
 			bb_perror_msg_and_die("poll");

 		fdidx = 0;
 		while (1) {
 			if (pfds[fdidx].revents) {
 				nread = safe_read(pfds[fdidx].fd, iobuf, COMMON_BUFSIZE);
 				if (fdidx != 0) {
 					if (nread < 1)
 						exit(EXIT_SUCCESS);
 					ofd = STDOUT_FILENO;
 				} else {
 					if (nread < 1) {
 						/* Close outgoing half-connection so they get EOF,
 						 * but leave incoming alone so we can see response */
 						shutdown(cfd, SHUT_WR);
 						pfds[0].fd = -1;
 					}
 					ofd = cfd;
 				}
 				xwrite(ofd, iobuf, nread);
 				if (delay > 0)
 					sleep(delay);
 			}
 			if (fdidx == 1)
 				break;
 			fdidx++;
 		}
 	}
 }
 #endif
	/* vi: set sw=4 ts=4: */
	/* nc: mini-netcat - built from the ground up for LRP
	*
	* Copyright (C) 1998, 1999 Charles P. Wright
	* Copyright (C) 1998 Dave Cinege
	*
	* Licensed under GPLv2 or later, see file LICENSE in this source tree.
	*/
	//config:config NC
	//config: bool "nc"
	//config: default y
	//config: help
	//config: A simple Unix utility which reads and writes data across network
	//config: connections.
	//config:
	//config:config NC_SERVER
	//config: bool "Netcat server options (-l)"
	//config: default y
	//config: depends on NC
	//config: help
	//config: Allow netcat to act as a server.
	//config:
	//config:config NC_EXTRA
	//config: bool "Netcat extensions (-eiw and -f FILE)"
	//config: default y
	//config: depends on NC
	//config: help
	//config: Add -e (support for executing the rest of the command line after
	//config: making or receiving a successful connection), -i (delay interval for
	//config: lines sent), -w (timeout for initial connection).
	//config:
	//config:config NC_110_COMPAT
	//config: bool "Netcat 1.10 compatibility (+2.5k)"
	//config: default n # off specially for Rob
	//config: depends on NC
	//config: help
	//config: This option makes nc closely follow original nc-1.10.
	//config: The code is about 2.5k bigger. It enables
	//config: -s ADDR, -n, -u, -v, -o FILE, -z options, but loses
	//config: busybox-specific extensions: -f FILE.

	//applet:IF_NC(APPLET(nc, BB_DIR_USR_BIN, BB_SUID_DROP))

	//kbuild:lib-$(CONFIG_NC) += nc.o

	#include "libbb.h"
	#include "common_bufsiz.h"
	#if ENABLE_NC_110_COMPAT
	# include "nc_bloaty.c"
	#else

	//usage:#if !ENABLE_NC_110_COMPAT
	//usage:
	//usage:#if ENABLE_NC_SERVER \|\| ENABLE_NC_EXTRA
	//usage:#define NC_OPTIONS_STR "\n"
	//usage:#else
	//usage:#define NC_OPTIONS_STR
	//usage:#endif
	//usage:
	//usage:#define nc_trivial_usage
	//usage: IF_NC_EXTRA("[-iN] [-wN] ")IF_NC_SERVER("[-l] [-p PORT] ")
	//usage: "["IF_NC_EXTRA("-f FILE\|")"IPADDR PORT]"IF_NC_EXTRA(" [-e PROG]")
	//usage:#define nc_full_usage "\n\n"
	//usage: "Open a pipe to IP:PORT" IF_NC_EXTRA(" or FILE")
	//usage: NC_OPTIONS_STR
	//usage: IF_NC_SERVER(
	//usage: "\n -l Listen mode, for inbound connects"
	//usage: IF_NC_EXTRA(
	//usage: "\n (use -ll with -e for persistent server)"
	//usage: )
	//usage: "\n -p PORT Local port"
	//usage: )
	//usage: IF_NC_EXTRA(
	//usage: "\n -w SEC Connect timeout"
	//usage: "\n -i SEC Delay interval for lines sent"
	//usage: "\n -f FILE Use file (ala /dev/ttyS0) instead of network"
	//usage: "\n -e PROG Run PROG after connect"
	//usage: )
	//usage:
	//usage:#define nc_notes_usage ""
	//usage: IF_NC_EXTRA(
	//usage: "To use netcat as a terminal emulator on a serial port:\n\n"
	//usage: "$ stty 115200 -F /dev/ttyS0\n"
	//usage: "$ stty raw -echo -ctlecho && nc -f /dev/ttyS0\n"
	//usage: )
	//usage:
	//usage:#define nc_example_usage
	//usage: "$ nc foobar.somedomain.com 25\n"
	//usage: "220 foobar ESMTP Exim 3.12 #1 Sat, 15 Apr 2000 00:03:02 -0600\n"
	//usage: "help\n"
	//usage: "214-Commands supported:\n"
	//usage: "214- HELO EHLO MAIL RCPT DATA AUTH\n"
	//usage: "214 NOOP QUIT RSET HELP\n"
	//usage: "quit\n"
	//usage: "221 foobar closing connection\n"
	//usage:
	//usage:#endif

	/* Lots of small differences in features
	* when compared to "standard" nc
	*/

	static void timeout(int signum UNUSED_PARAM)
	{
	bb_error_msg_and_die("timed out");
	}

	int nc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
	int nc_main(int argc, char **argv)
	{
	/* sfd sits _here_ only because of "repeat" option (-l -l). */
	int sfd = sfd; /* for gcc */
	int cfd = 0;
	unsigned lport = 0;
	IF_NOT_NC_SERVER(const) unsigned do_listen = 0;
	IF_NOT_NC_EXTRA (const) unsigned wsecs = 0;
	IF_NOT_NC_EXTRA (const) unsigned delay = 0;
	IF_NOT_NC_EXTRA (const int execparam = 0;)
	IF_NC_EXTRA (char **execparam = NULL;)
	struct pollfd pfds[2];
	int opt; /* must be signed (getopt returns -1) */

	if (ENABLE_NC_SERVER \|\| ENABLE_NC_EXTRA) {
	/* getopt32 is _almost_ usable:
	** it cannot handle "... -e PROG -prog-opt" */
	while ((opt = getopt(argc, argv,
	"" IF_NC_SERVER("lp:") IF_NC_EXTRA("w:i:f:e:") )) > 0
	) {
	if (ENABLE_NC_SERVER && opt == 'l')
	IF_NC_SERVER(do_listen++);
	else if (ENABLE_NC_SERVER && opt == 'p')
	IF_NC_SERVER(lport = bb_lookup_port(optarg, "tcp", 0));
	else if (ENABLE_NC_EXTRA && opt == 'w')
	IF_NC_EXTRA( wsecs = xatou(optarg));
	else if (ENABLE_NC_EXTRA && opt == 'i')
	IF_NC_EXTRA( delay = xatou(optarg));
	else if (ENABLE_NC_EXTRA && opt == 'f')
	IF_NC_EXTRA( cfd = xopen(optarg, O_RDWR));
	else if (ENABLE_NC_EXTRA && opt == 'e' && optind <= argc) {
	/* We cannot just 'break'. We should let getopt finish.
	** Or else we won't be able to find where
	** 'host' and 'port' params are
	** (think "nc -w 60 host port -e PROG"). */
	IF_NC_EXTRA(
	char **p;
	// +2: one for progname (optarg) and one for NULL
	execparam = xzalloc(sizeof(char) (argc - optind + 2));
	p = execparam;
	*p++ = optarg;
	while (optind < argc) {
	*p++ = argv[optind++];
	}
	)
	/* optind points to argv[argc] (NULL) now.
	** FIXME: we assume that getopt will not count options
	** possibly present on "-e PROG ARGS" and will not
	** include them into final value of optind
	** which is to be used ... */
	} else bb_show_usage();
	}
	argv += optind; /* ... here! */
	argc -= optind;
	// -l and -f don't mix
	if (do_listen && cfd) bb_show_usage();
	// File mode needs need zero arguments, listen mode needs zero or one,
	// client mode needs one or two
	if (cfd) {
	if (argc) bb_show_usage();
	} else if (do_listen) {
	if (argc > 1) bb_show_usage();
	} else {
	if (!argc \|\| argc > 2) bb_show_usage();
	}
	} else {
	if (argc != 3) bb_show_usage();
	argc--;
	argv++;
	}

	if (wsecs) {
	signal(SIGALRM, timeout);
	alarm(wsecs);
	}

	if (!cfd) {
	if (do_listen) {
	sfd = create_and_bind_stream_or_die(argv[0], lport);
	xlisten(sfd, do_listen); /* can be > 1 */
	#if 0 /* nc-1.10 does not do this (without -v) */
	/* If we didn't specify a port number,
	* query and print it after listen() */
	if (!lport) {
	len_and_sockaddr lsa;
	lsa.len = LSA_SIZEOF_SA;
	getsockname(sfd, &lsa.u.sa, &lsa.len);
	lport = get_nport(&lsa.u.sa);
	fdprintf(2, "%d\n", ntohs(lport));
	}
	#endif
	close_on_exec_on(sfd);
	accept_again:
	cfd = accept(sfd, NULL, 0);
	if (cfd < 0)
	bb_perror_msg_and_die("accept");
	if (!execparam)
	close(sfd);
	} else {
	cfd = create_and_connect_stream_or_die(argv[0],
	argv[1] ? bb_lookup_port(argv[1], "tcp", 0) : 0);
	}
	}

	if (wsecs) {
	alarm(0);
	/* Non-ignored signals revert to SIG_DFL on exec anyway */
	/signal(SIGALRM, SIG_DFL);/
	}

	/* -e given? */
	if (execparam) {
	pid_t pid;
	/* With more than one -l, repeatedly act as server */
	if (do_listen > 1 && (pid = xvfork()) != 0) {
	/* parent */
	/* prevent zombies */
	signal(SIGCHLD, SIG_IGN);
	close(cfd);
	goto accept_again;
	}
	/* child, or main thread if only one -l */
	xmove_fd(cfd, 0);
	xdup2(0, 1);
	/xdup2(0, 2); - original nc 1.10 does this, we don't /
	IF_NC_EXTRA(BB_EXECVP(execparam[0], execparam);)
	IF_NC_EXTRA(bb_perror_msg_and_die("can't execute '%s'", execparam[0]);)
	}

	/* loop copying stdin to cfd, and cfd to stdout */

	pfds[0].fd = STDIN_FILENO;
	pfds[0].events = POLLIN;
	pfds[1].fd = cfd;
	pfds[1].events = POLLIN;

	#define iobuf bb_common_bufsiz1
	setup_common_bufsiz();
	for (;;) {
	int fdidx;
	int ofd;
	int nread;

	if (safe_poll(pfds, 2, -1) < 0)
	bb_perror_msg_and_die("poll");

	fdidx = 0;
	while (1) {
	if (pfds[fdidx].revents) {
	nread = safe_read(pfds[fdidx].fd, iobuf, COMMON_BUFSIZE);
	if (fdidx != 0) {
	if (nread < 1)
	exit(EXIT_SUCCESS);
	ofd = STDOUT_FILENO;
	} else {
	if (nread < 1) {
	/* Close outgoing half-connection so they get EOF,
	* but leave incoming alone so we can see response */
	shutdown(cfd, SHUT_WR);
	pfds[0].fd = -1;
	}
	ofd = cfd;
	}
	xwrite(ofd, iobuf, nread);
	if (delay > 0)
	sleep(delay);
	}
	if (fdidx == 1)
	break;
	fdidx++;
	}
	}
	}
	#endif