X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Fnc.c;h=b208f46c638f78f04e6d27592398d00766b16a2a;hb=5740e15de55baa343955196c641baeaec8a73b5c;hp=9a353c94f81c7aa2c87652b7b6228e681bd6ebf4;hpb=c7bda1ce659294d6e22c06e087f6f265983c7578;p=oweals%2Fbusybox.git diff --git a/networking/nc.c b/networking/nc.c index 9a353c94f..b208f46c6 100644 --- a/networking/nc.c +++ b/networking/nc.c @@ -1,177 +1,292 @@ /* vi: set sw=4 ts=4: */ -/* nc: mini-netcat - built from the ground up for LRP - Copyright (C) 1998 Charles P. Wright - - 0.0.1 6K It works. - 0.0.2 5K Smaller and you can also check the exit condition if you wish. - 0.0.3 Uses select() - - 19980918 Busy Boxed! Dave Cinege - 19990512 Uses Select. Charles P. Wright - 19990513 Fixes stdin stupidity and uses buffers. Charles P. Wright - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - -*/ - -#include -#include -#include -#include - -#include -#include -#include -#include -#include -#include -#include -#include "busybox.h" - -#define GAPING_SECURITY_HOLE +/* + * 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. + +//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 + +#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) { - int do_listen = 0, lport = 0, delay = 0, tmpfd, opt, sfd, x; - char buf[BUFSIZ]; -#ifdef GAPING_SECURITY_HOLE - char * pr00gie = NULL; -#endif - - struct sockaddr_in address; - struct hostent *hostinfo; - - fd_set readfds, testfds; - - while ((opt = getopt(argc, argv, "lp:i:e:")) > 0) { - switch (opt) { - case 'l': - do_listen++; - break; - case 'p': - lport = bb_lookup_port(optarg, "tcp", 0); - break; - case 'i': - delay = atoi(optarg); - break; -#ifdef GAPING_SECURITY_HOLE - case 'e': - pr00gie = optarg; - break; -#endif - default: - bb_show_usage(); + /* 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++; } -#ifdef GAPING_SECURITY_HOLE - if (pr00gie) { - /* won't need stdin */ - close (fileno(stdin)); + if (wsecs) { + signal(SIGALRM, timeout); + alarm(wsecs); } -#endif /* GAPING_SECURITY_HOLE */ - - - if ((do_listen && optind != argc) || (!do_listen && optind + 2 != argc)) - bb_show_usage(); - if ((sfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) - bb_perror_msg_and_die("socket"); - x = 1; - if (setsockopt (sfd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof (x)) == -1) - bb_perror_msg_and_die ("reuseaddr failed"); - address.sin_family = AF_INET; - - if (lport != 0) { - memset(&address.sin_addr, 0, sizeof(address.sin_addr)); - address.sin_port = lport; - - if (bind(sfd, (struct sockaddr *) &address, sizeof(address)) < 0) - bb_perror_msg_and_die("bind"); + 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 (do_listen) { - socklen_t addrlen = sizeof(address); - - if (listen(sfd, 1) < 0) - bb_perror_msg_and_die("listen"); - - if ((tmpfd = accept(sfd, (struct sockaddr *) &address, &addrlen)) < 0) - bb_perror_msg_and_die("accept"); - - close(sfd); - sfd = tmpfd; - } 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"); + if (wsecs) { + alarm(0); + /* Non-ignored signals revert to SIG_DFL on exec anyway */ + /*signal(SIGALRM, SIG_DFL);*/ } -#ifdef GAPING_SECURITY_HOLE /* -e given? */ - if (pr00gie) { - dup2(sfd, 0); - close(sfd); - dup2 (0, 1); - dup2 (0, 2); - execl (pr00gie, pr00gie, NULL); - /* Don't print stuff or it will go over the wire.... */ - _exit(-1); + 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]);) } -#endif /* GAPING_SECURITY_HOLE */ + /* loop copying stdin to cfd, and cfd to stdout */ - FD_ZERO(&readfds); - FD_SET(sfd, &readfds); - FD_SET(STDIN_FILENO, &readfds); + pfds[0].fd = STDIN_FILENO; + pfds[0].events = POLLIN; + pfds[1].fd = cfd; + pfds[1].events = POLLIN; - while (1) { - int fd; +#define iobuf bb_common_bufsiz1 + setup_common_bufsiz(); + for (;;) { + 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)) { - if ((nread = safe_read(fd, buf, sizeof(buf))) < 0) - bb_perror_msg_and_die("read"); - - if (fd == sfd) { - if (nread == 0) - 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 == 0) - shutdown(sfd, 1); - ofd = sfd; + 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; } - - if (bb_full_write(ofd, buf, nread) < 0) - bb_perror_msg_and_die("write"); - if (delay > 0) { + xwrite(ofd, iobuf, nread); + if (delay > 0) sleep(delay); - } } + if (fdidx == 1) + break; + fdidx++; } } } +#endif