| /* netcat.c - Forward stdin/stdout to a file or network connection. |
| * |
| * Copyright 2007 Rob Landley <rob@landley.net> |
| * |
| * TODO: udp, ipv6, genericize for telnet/microcom/tail-f |
| * fix -t, xconnect |
| * netcat -L zombies |
| |
| USE_NETCAT(OLDTOY(nc, netcat, TOYFLAG_USR|TOYFLAG_BIN)) |
| USE_NETCAT(NEWTOY(netcat, USE_NETCAT_LISTEN("^tlL")"w#<1W#<1p#<1>65535q#<1s:f:46uU"USE_NETCAT_LISTEN("[!tlL][!Lw]")"[!46U]", TOYFLAG_BIN)) |
| |
| config NETCAT |
| bool "netcat" |
| default y |
| help |
| usage: netcat [-46U] [-u] [-wpq #] [-s addr] {IPADDR PORTNUM|-f FILENAME} |
| |
| Forward stdin/stdout to a file or network connection. |
| |
| -4 Force IPv4 |
| -6 Force IPv6 |
| -f Use FILENAME (ala /dev/ttyS0) instead of network |
| -p Local port number |
| -q Quit SECONDS after EOF on stdin, even if stdout hasn't closed yet |
| -s Local source address |
| -u Use UDP |
| -U Use a UNIX domain socket |
| -w SECONDS timeout to establish connection |
| -W SECONDS timeout for more data on an idle connection |
| |
| Use "stty 115200 -F /dev/ttyS0 && stty raw -echo -ctlecho" with |
| netcat -f to connect to a serial port. |
| |
| config NETCAT_LISTEN |
| bool "netcat server options (-let)" |
| default y |
| depends on NETCAT |
| help |
| usage: netcat [-t] [-lL COMMAND...] |
| |
| -l Listen for one incoming connection |
| -L Listen for multiple incoming connections (server mode) |
| -t Allocate tty (must come before -l or -L) |
| |
| The command line after -l or -L is executed (as a child process) to handle |
| each incoming connection. If blank -l waits for a connection and forwards |
| it to stdin/stdout. If no -p specified, -l prints port it bound to and |
| backgrounds itself (returning immediately). |
| |
| For a quick-and-dirty server, try something like: |
| netcat -s 127.0.0.1 -p 1234 -tL /bin/bash -l |
| */ |
| |
| #define FOR_netcat |
| #include "toys.h" |
| |
| GLOBALS( |
| char *f, *s; |
| long q, p, W, w; |
| ) |
| |
| static void timeout(int signum) |
| { |
| if (TT.w) error_exit("Timeout"); |
| xexit(); |
| } |
| |
| static void set_alarm(int seconds) |
| { |
| xsignal(SIGALRM, seconds ? timeout : SIG_DFL); |
| alarm(seconds); |
| } |
| |
| void netcat_main(void) |
| { |
| int sockfd = -1, in1 = 0, in2 = 0, out1 = 1, out2 = 1; |
| int family = AF_UNSPEC, type = SOCK_STREAM; |
| pid_t child; |
| |
| // Addjust idle and quit_delay to ms or -1 for no timeout |
| TT.W = TT.W ? TT.W*1000 : -1; |
| TT.q = TT.q ? TT.q*1000 : -1; |
| |
| set_alarm(TT.w); |
| |
| // The argument parsing logic can't make "<2" conditional on other |
| // arguments like -f and -l, so do it by hand here. |
| if ((toys.optflags&FLAG_f) ? toys.optc : |
| (!(toys.optflags&(FLAG_l|FLAG_L)) && |
| toys.optc!=(toys.optflags&FLAG_U?1:2))) |
| help_exit("bad argument count"); |
| |
| if (toys.optflags&FLAG_4) family = AF_INET; |
| else if (toys.optflags&FLAG_6) family = AF_INET6; |
| else if (toys.optflags&FLAG_U) family = AF_UNIX; |
| |
| if (toys.optflags&FLAG_u) type = SOCK_DGRAM; |
| |
| if (TT.f) in1 = out2 = xopen(TT.f, O_RDWR); |
| else { |
| // Setup socket |
| if (!(toys.optflags&(FLAG_L|FLAG_l))) { |
| if (toys.optflags&FLAG_U) { |
| struct sockaddr_un sockaddr; |
| |
| memset(&sockaddr, 0, sizeof(struct sockaddr_un)); |
| |
| if (strlen(toys.optargs[0]) + 1 > sizeof(sockaddr.sun_path)) |
| error_exit("socket path too long %s", toys.optargs[0]); |
| strcpy(sockaddr.sun_path, toys.optargs[0]); |
| sockaddr.sun_family = AF_UNIX; |
| |
| sockfd = xsocket(AF_UNIX, type | SOCK_CLOEXEC, 0); |
| if (connect(sockfd, (struct sockaddr*)&sockaddr, |
| sizeof(sockaddr)) != 0) { |
| perror_exit("could not bind to unix domain socket"); |
| } |
| |
| } else { |
| struct addrinfo *addr = xgetaddrinfo(toys.optargs[0], toys.optargs[1], |
| family, type, 0, 0); |
| |
| sockfd = xconnect(addr); |
| } |
| |
| // We have a connection. Disarm timeout. |
| set_alarm(0); |
| |
| in1 = out2 = sockfd; |
| |
| pollinate(in1, in2, out1, out2, TT.W, TT.q); |
| } else { |
| // Listen for incoming connections |
| if (toys.optflags&FLAG_U) { |
| struct sockaddr_un sockaddr; |
| |
| memset(&sockaddr, 0, sizeof(struct sockaddr_un)); |
| |
| if (!(toys.optflags&FLAG_s)) |
| error_exit("-s must be provided if using -U with -L/-l"); |
| |
| if (strlen(TT.s) + 1 > sizeof(sockaddr.sun_path)) |
| error_exit("socket path too long %s", TT.s); |
| strcpy(sockaddr.sun_path, TT.s); |
| sockaddr.sun_family = AF_UNIX; |
| |
| sockfd = xsocket(AF_UNIX, type | SOCK_CLOEXEC, 0); |
| if (bind(sockfd, (struct sockaddr*)&sockaddr, |
| sizeof(struct sockaddr_un)) != 0) { |
| perror_exit("unable to bind to UNIX domain socket"); |
| } |
| } else { |
| sprintf(toybuf, "%ld", TT.p); |
| sockfd = xbind(xgetaddrinfo(TT.s, toybuf, family, type, 0, 0)); |
| } |
| |
| if (listen(sockfd, 5)) error_exit("listen"); |
| if (!TT.p && !(toys.optflags&FLAG_U)) { |
| struct sockaddr* address = (void*)toybuf; |
| socklen_t len = sizeof(struct sockaddr_storage); |
| short port_be; |
| |
| getsockname(sockfd, address, &len); |
| if (address->sa_family == AF_INET) |
| port_be = ((struct sockaddr_in*)address)->sin_port; |
| else if (address->sa_family == AF_INET6) |
| port_be = ((struct sockaddr_in6*)address)->sin6_port; |
| else |
| perror_exit("getsockname: bad family"); |
| |
| printf("%d\n", SWAP_BE16(port_be)); |
| fflush(stdout); |
| // Return immediately if no -p and -Ll has arguments, so wrapper |
| // script can use port number. |
| if (CFG_TOYBOX_FORK && toys.optc && xfork()) goto cleanup; |
| } |
| |
| do { |
| child = 0; |
| in1 = out2 = accept(sockfd, NULL, NULL); |
| if (in1<0) perror_exit("accept"); |
| |
| // We have a connection. Disarm timeout. |
| set_alarm(0); |
| |
| if (toys.optc) { |
| // Do we need a tty? |
| |
| // TODO nommu, and -t only affects server mode...? Only do -t with optc |
| // if (CFG_TOYBOX_FORK && (toys.optflags&FLAG_t)) |
| // child = forkpty(&fdout, NULL, NULL, NULL); |
| // else |
| |
| // Do we need to fork and/or redirect for exec? |
| |
| if (toys.optflags&FLAG_L) NOEXIT(child = XVFORK()); |
| if (child) { |
| close(in1); |
| continue; |
| } |
| dup2(in1, 0); |
| dup2(in1, 1); |
| if (toys.optflags&FLAG_L) dup2(in1, 2); |
| if (in1>2) close(in1); |
| xexec(toys.optargs); |
| } |
| |
| pollinate(in1, in2, out1, out2, TT.W, TT.q); |
| close(in1); |
| } while (!(toys.optflags&FLAG_l)); |
| } |
| } |
| |
| cleanup: |
| if (CFG_TOYBOX_FREE) { |
| close(in1); |
| close(sockfd); |
| } |
| } |
