/* vi: set sw=4 ts=4: */
-/* nc: mini-netcat - built from the ground up for LRP
+/*
+ * nc: mini-netcat - built from the ground up for LRP
*
- * Copyright (C) 1998, 1999 Charles P. Wright
- * Copyright (C) 1998 Dave Cinege
+ * Copyright (C) 1998, 1999 Charles P. Wright
+ * Copyright (C) 1998 Dave Cinege
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
+//config:config NC
+//config: bool "nc (11 kb)"
+//config: default y
+//config: help
+//config: A simple Unix utility which reads and writes data across network
+//config: connections.
+//config:
+//config:config NETCAT
+//config: bool "netcat (11 kb)"
+//config: default n
+//config: help
+//config: Alias to nc.
+//config:
+//config:config NC_SERVER
+//config: bool "Netcat server options (-l)"
+//config: default y
+//config: depends on NC || NETCAT
+//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 || NETCAT
+//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 y
+//config: depends on NC || NETCAT
+//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.
-#include "libbb.h"
+//applet:IF_NC(APPLET(nc, BB_DIR_USR_BIN, BB_SUID_DROP))
+// APPLET_ODDNAME:name main location suid_type help
+//applet:IF_NETCAT(APPLET_ODDNAME(netcat, nc, BB_DIR_USR_BIN, BB_SUID_DROP, nc))
+
+//kbuild:lib-$(CONFIG_NC) += nc.o
+//kbuild:lib-$(CONFIG_NETCAT) += nc.o
-#if ENABLE_DESKTOP
-#include "nc_bloaty.c"
+#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)
+static void timeout(int signum UNUSED_PARAM)
{
bb_error_msg_and_die("timed out");
}
-int nc_main(int argc, char **argv);
+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;
- SKIP_NC_SERVER(const) unsigned do_listen = 0;
- SKIP_NC_EXTRA (const) unsigned wsecs = 0;
- SKIP_NC_EXTRA (const) unsigned delay = 0;
- SKIP_NC_EXTRA (const int execparam = 0;)
- USE_NC_EXTRA (char **execparam = NULL;)
- len_and_sockaddr *lsa;
- fd_set readfds, testfds;
+ 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" */
+ ** it cannot handle "... -e PROG -prog-opt" */
while ((opt = getopt(argc, argv,
- "" USE_NC_SERVER("lp:") USE_NC_EXTRA("w:i:f:e:") )) > 0
+ "" IF_NC_SERVER("lp:") IF_NC_EXTRA("w:i:f:e:") )) > 0
) {
- if (ENABLE_NC_SERVER && opt=='l') USE_NC_SERVER(do_listen++);
- else if (ENABLE_NC_SERVER && opt=='p') {
- USE_NC_SERVER(lport = bb_lookup_port(optarg, "tcp", 0));
- }
- else if (ENABLE_NC_EXTRA && opt=='w') USE_NC_EXTRA( wsecs = xatou(optarg));
- else if (ENABLE_NC_EXTRA && opt=='i') USE_NC_EXTRA( delay = xatou(optarg));
- else if (ENABLE_NC_EXTRA && opt=='f') USE_NC_EXTRA( cfd = xopen(optarg, O_RDWR));
- else if (ENABLE_NC_EXTRA && opt=='e' && optind<=argc) {
+ 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"). */
- USE_NC_EXTRA(
+ ** (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++ = argv[optind++];
}
)
- /* optind points to argv[arvc] (NULL) now.
+ /* 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
+ ** 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();
argc -= optind;
// -l and -f don't mix
if (do_listen && cfd) bb_show_usage();
- // Listen or file modes need zero arguments, client mode needs 2
- if (do_listen || cfd) {
+ // 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();
}
if (!cfd) {
if (do_listen) {
- /* create_and_bind_stream_or_die(NULL, lport)
- * would've work wonderfully, but we need
- * to know lsa */
- sfd = xsocket_stream(&lsa);
- if (lport)
- set_nport(lsa, htons(lport));
- setsockopt_reuseaddr(sfd);
- xbind(sfd, &lsa->sa, lsa->len);
+ 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) {
- socklen_t addrlen = lsa->len;
- getsockname(sfd, &lsa->sa, &addrlen);
- lport = get_nport(&lsa->sa);
+ 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));
}
- fcntl(sfd, F_SETFD, FD_CLOEXEC);
+#endif
+ close_on_exec_on(sfd);
accept_again:
cfd = accept(sfd, NULL, 0);
if (cfd < 0)
if (wsecs) {
alarm(0);
- signal(SIGALRM, SIG_DFL);
+ /* Non-ignored signals revert to SIG_DFL on exec anyway */
+ /*signal(SIGALRM, SIG_DFL);*/
}
/* -e given? */
if (execparam) {
- signal(SIGCHLD, SIG_IGN);
- // With more than one -l, repeatedly act as server.
- if (do_listen > 1 && vfork()) {
+ pid_t pid;
+ /* With more than one -l, repeatedly act as server */
+ if (do_listen > 1 && (pid = xvfork()) != 0) {
/* parent */
- // This is a bit weird as cleanup goes, since we wind up with no
- // stdin/stdout/stderr. But it's small and shouldn't hurt anything.
- // We check for cfd == 0 above.
- logmode = LOGMODE_NONE;
- close(0);
- close(1);
- close(2);
- goto accept_again;
- }
- /* child (or main thread if no multiple -l) */
- if (cfd) {
- dup2(cfd, 0);
+ /* prevent zombies */
+ signal(SIGCHLD, SIG_IGN);
close(cfd);
+ goto accept_again;
}
- dup2(0, 1);
- dup2(0, 2);
- USE_NC_EXTRA(BB_EXECVP(execparam[0], execparam);)
- /* Don't print stuff or it will go over the wire.... */
- _exit(127);
+ /* 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]);)
}
- // Select loop copying stdin to cfd, and cfd to stdout.
+ /* loop copying stdin to cfd, and cfd to stdout */
- FD_ZERO(&readfds);
- FD_SET(cfd, &readfds);
- FD_SET(STDIN_FILENO, &readfds);
+ 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 fd;
+ int fdidx;
int ofd;
int nread;
- testfds = readfds;
-
- if (select(FD_SETSIZE, &testfds, NULL, NULL, NULL) < 0)
- bb_perror_msg_and_die("select");
+ if (safe_poll(pfds, 2, -1) < 0)
+ bb_perror_msg_and_die("poll");
-#define iobuf bb_common_bufsiz1
- for (fd = 0; fd < FD_SETSIZE; fd++) {
- if (FD_ISSET(fd, &testfds)) {
- nread = safe_read(fd, iobuf, sizeof(iobuf));
- if (fd == cfd) {
+ fdidx = 0;
+ while (1) {
+ if (pfds[fdidx].revents) {
+ nread = safe_read(pfds[fdidx].fd, iobuf, COMMON_BUFSIZE);
+ if (fdidx != 0) {
if (nread < 1)
- exit(0);
+ 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, 1);
- FD_CLR(STDIN_FILENO, &readfds);
+ 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 (delay > 0)
+ sleep(delay);
}
+ if (fdidx == 1)
+ break;
+ fdidx++;
}
}
}
projects / oweals / busybox.git / blobdiff