X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Fnc.c;h=1b32e3aa334893b7eba4fe937a260bf0fcc5d3d4;hb=d38ca03946000f0837e9a0e04937499509db54c4;hp=1bdecaf5eb8018092deeddf1a773aabe8abce445;hpb=1d76f439da81d3a05f0e0fdde3f81ec56fb20836;p=oweals%2Fbusybox.git diff --git a/networking/nc.c b/networking/nc.c index 1bdecaf5e..1b32e3aa3 100644 --- a/networking/nc.c +++ b/networking/nc.c @@ -1,58 +1,143 @@ /* 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. */ -#include "busybox.h" +#include "libbb.h" + +//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 filename)" +//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 and -ll. + +#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_EXTRA( +//usage: "\n -e PROG Run PROG after connect" +//usage: IF_NC_SERVER( +//usage: "\n -l Listen mode, for inbound connects" +//usage: IF_NC_EXTRA( +//usage: "\n (use -l twice with -e for persistent server)") +//usage: "\n -p PORT Local port" +//usage: ) +//usage: "\n -w SEC Timeout for connect" +//usage: "\n -i SEC Delay interval for lines sent" +//usage: "\n -f FILE Use file (ala /dev/ttyS0) instead of network" +//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; + 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;) fd_set readfds, testfds; 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)); @@ -64,7 +149,7 @@ int nc_main(int argc, char **argv) ) /* optind points to argv[arvc] (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(); @@ -73,9 +158,12 @@ int nc_main(int argc, char **argv) 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(); } @@ -92,24 +180,20 @@ int nc_main(int argc, char **argv) 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); + 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) @@ -124,37 +208,31 @@ int nc_main(int argc, char **argv) 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.... */ + /* child, or main thread if only one -l */ + xmove_fd(cfd, 0); + xdup2(0, 1); + xdup2(0, 2); + IF_NC_EXTRA(BB_EXECVP(execparam[0], execparam);) + /* Don't print stuff or it will go over the wire... */ _exit(127); } - // Select loop copying stdin to cfd, and cfd to stdout. + /* Select loop copying stdin to cfd, and cfd to stdout */ FD_ZERO(&readfds); FD_SET(cfd, &readfds); @@ -167,31 +245,35 @@ int nc_main(int argc, char **argv) testfds = readfds; - if (select(FD_SETSIZE, &testfds, NULL, NULL, NULL) < 0) + if (select(cfd + 1, &testfds, NULL, NULL, NULL) < 0) bb_perror_msg_and_die("select"); - for (fd = 0; fd < FD_SETSIZE; fd++) { +#define iobuf bb_common_bufsiz1 + fd = STDIN_FILENO; + while (1) { if (FD_ISSET(fd, &testfds)) { - nread = safe_read(fd, bb_common_bufsiz1, - sizeof(bb_common_bufsiz1)); - + nread = safe_read(fd, iobuf, sizeof(iobuf)); if (fd == cfd) { 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. + 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); } ofd = cfd; } - - xwrite(ofd, bb_common_bufsiz1, nread); - if (delay > 0) sleep(delay); + xwrite(ofd, iobuf, nread); + if (delay > 0) + sleep(delay); } + if (fd == cfd) + break; + fd = cfd; } } } +#endif