/* 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 tarball for details.
+/*
+ * 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 (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 "busybox.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))
-static void timeout(int signum)
+//kbuild:lib-$(CONFIG_NC) += nc.o
+//kbuild:lib-$(CONFIG_NETCAT) += 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");
+ bb_error_msg_and_die("timed out");
}
+int nc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int nc_main(int argc, char **argv)
{
- int do_listen = 0, lport = 0, delay = 0, wsecs = 0, execflag = 0, opt,
- sfd = 0, cfd;
- struct sockaddr_in address;
- struct hostent *hostinfo;
- fd_set readfds, testfds;
- char *infile = NULL;
-
- memset(&address, 0, sizeof(address));
-
- if (ENABLE_NC_SERVER || ENABLE_NC_EXTRA) {
- while ((opt = getopt(argc, argv, "lp:" USE_NC_EXTRA("i:ew:f:"))) > 0) {
- if (ENABLE_NC_SERVER && opt=='l') do_listen++;
- else if (ENABLE_NC_SERVER && opt=='p')
- lport = bb_lookup_port(optarg, "tcp", 0);
- else if (ENABLE_NC_EXTRA && opt=='w') wsecs = atoi(optarg);
- else if (ENABLE_NC_EXTRA && opt=='i') delay = atoi(optarg);
- else if (ENABLE_NC_EXTRA && opt=='f') infile = optarg;
- else if (ENABLE_NC_EXTRA && opt=='e' && optind!=argc) {
- execflag++;
- break;
+ /* 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++;
}
-
- // For listen or file we need zero arguments, dialout is 2.
- // For exec we need at least one more argument at the end, more ok
-
- opt = (do_listen || infile) ? 0 : 2 + execflag;
- if (execflag ? argc-optind < opt : argc-optind!=opt ||
- (infile && do_listen))
- bb_show_usage();
-
if (wsecs) {
signal(SIGALRM, timeout);
alarm(wsecs);
}
-
- if (infile) cfd = xopen(infile, O_RDWR);
- else {
- opt = 1;
- sfd = xsocket(AF_INET, SOCK_STREAM, 0);
- fcntl(sfd, F_SETFD, FD_CLOEXEC);
- setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof (opt));
- address.sin_family = AF_INET;
-
- // Set local port.
-
- if (lport != 0) {
- address.sin_port = lport;
-
- xbind(sfd, (struct sockaddr *) &address, sizeof(address));
- }
+ if (!cfd) {
if (do_listen) {
- socklen_t addrlen = sizeof(address);
-
- xlisten(sfd, do_listen);
-
- // If we didn't specify a port number, query and print it to stderr.
-
+ 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 len = sizeof(address);
- getsockname(sfd, &address, &len);
- fdprintf(2, "%d\n", SWAP_BE16(address.sin_port));
+ 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));
}
-repeatyness:
- if ((cfd = accept(sfd, (struct sockaddr *) &address, &addrlen)) < 0)
+#endif
+ close_on_exec_on(sfd);
+ accept_again:
+ cfd = accept(sfd, NULL, 0);
+ if (cfd < 0)
bb_perror_msg_and_die("accept");
-
- if (!execflag) close(sfd);
+ if (!execparam)
+ close(sfd);
} else {
- hostinfo = xgethostbyname(argv[optind]);
-
- address.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
- address.sin_port = bb_lookup_port(argv[optind+1], "tcp", 0);
-
- if (connect(sfd, (struct sockaddr *) &address, sizeof(address)) < 0)
- bb_perror_msg_and_die("connect");
- cfd = sfd;
+ cfd = create_and_connect_stream_or_die(argv[0],
+ argv[1] ? bb_lookup_port(argv[1], "tcp", 0) : 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 (execflag) {
- if(cfd) {
+ 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);
- dup2(cfd, 0);
close(cfd);
+ goto accept_again;
}
- dup2(0, 1);
- dup2(0, 2);
-
- // With more than one -l, repeatedly act as server.
-
- if (do_listen>1 && vfork()) {
- // 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.
- close(0);
- close(1);
- close(2);
-
- goto repeatyness;
- }
- execvp(argv[optind], argv+optind);
- /* 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.
-
- FD_ZERO(&readfds);
- FD_SET(cfd, &readfds);
- FD_SET(STDIN_FILENO, &readfds);
+ /* 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 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");
- for (fd = 0; fd < FD_SETSIZE; fd++) {
- if (FD_ISSET(fd, &testfds)) {
- nread = safe_read(fd, bb_common_bufsiz1,
- sizeof(bb_common_bufsiz1));
-
- if (fd == cfd) {
- if (nread<1) exit(0);
+ 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, 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, bb_common_bufsiz1, nread);
- if (delay > 0) sleep(delay);
+ xwrite(ofd, iobuf, nread);
+ if (delay > 0)
+ sleep(delay);
}
+ if (fdidx == 1)
+ break;
+ fdidx++;
}
}
}
+#endif
projects / oweals / busybox.git / blobdiff