pax_global_header00006660000000000000000000000064130112171760014511gustar00rootroot0000000000000052 comment=1282b14067cd13bfc7d25985ca9ab52e803d8908 netcat-openbsd-1.130/000077500000000000000000000000001301121717600144235ustar00rootroot00000000000000netcat-openbsd-1.130/Makefile000066400000000000000000000001771301121717600160700ustar00rootroot00000000000000# $OpenBSD: Makefile,v 1.6 2001/09/02 18:45:41 jakob Exp $ PROG= nc SRCS= netcat.c atomicio.c socks.c .include netcat-openbsd-1.130/atomicio.c000066400000000000000000000042651301121717600164020ustar00rootroot00000000000000/* $OpenBSD: atomicio.c,v 1.11 2012/12/04 02:24:47 deraadt Exp $ */ /* * Copyright (c) 2006 Damien Miller. All rights reserved. * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved. * Copyright (c) 1995,1999 Theo de Raadt. All rights reserved. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include "atomicio.h" /* * ensure all of data on socket comes through. f==read || f==vwrite */ size_t atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) { char *s = _s; size_t pos = 0; ssize_t res; struct pollfd pfd; pfd.fd = fd; pfd.events = f == read ? POLLIN : POLLOUT; while (n > pos) { res = (f) (fd, s + pos, n - pos); switch (res) { case -1: if (errno == EINTR) continue; if ((errno == EAGAIN) || (errno == ENOBUFS)) { (void)poll(&pfd, 1, -1); continue; } return 0; case 0: errno = EPIPE; return pos; default: pos += (size_t)res; } } return (pos); } netcat-openbsd-1.130/atomicio.h000066400000000000000000000033161301121717600164030ustar00rootroot00000000000000/* $OpenBSD: atomicio.h,v 1.2 2007/09/07 14:50:44 tobias Exp $ */ /* * Copyright (c) 2006 Damien Miller. All rights reserved. * Copyright (c) 1995,1999 Theo de Raadt. All rights reserved. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef _ATOMICIO_H #define _ATOMICIO_H /* * Ensure all of data on socket comes through. f==read || f==vwrite */ size_t atomicio(ssize_t (*)(int, void *, size_t), int, void *, size_t); #define vwrite (ssize_t (*)(int, void *, size_t))write #endif /* _ATOMICIO_H */ netcat-openbsd-1.130/nc.1000066400000000000000000000306501301121717600151110ustar00rootroot00000000000000.\" $OpenBSD: nc.1,v 1.68 2015/03/26 10:35:04 tobias Exp $ .\" .\" Copyright (c) 1996 David Sacerdote .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. The name of the author may not be used to endorse or promote products .\" derived from this software without specific prior written permission .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. .\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: March 26 2015 $ .Dt NC 1 .Os .Sh NAME .Nm nc .Nd arbitrary TCP and UDP connections and listens .Sh SYNOPSIS .Nm nc .Bk -words .Op Fl 46DdFhklNnrStUuvz .Op Fl I Ar length .Op Fl i Ar interval .Op Fl O Ar length .Op Fl P Ar proxy_username .Op Fl p Ar source_port .Op Fl s Ar source .Op Fl T Ar toskeyword .Op Fl V Ar rtable .Op Fl w Ar timeout .Op Fl X Ar proxy_protocol .Oo Xo .Fl x Ar proxy_address Ns Oo : Ns .Ar port Oc .Xc Oc .Op Ar destination .Op Ar port .Ek .Sh DESCRIPTION The .Nm (or .Nm netcat ) utility is used for just about anything under the sun involving TCP, UDP, or .Ux Ns -domain sockets. It can open TCP connections, send UDP packets, listen on arbitrary TCP and UDP ports, do port scanning, and deal with both IPv4 and IPv6. Unlike .Xr telnet 1 , .Nm scripts nicely, and separates error messages onto standard error instead of sending them to standard output, as .Xr telnet 1 does with some. .Pp Common uses include: .Pp .Bl -bullet -offset indent -compact .It simple TCP proxies .It shell-script based HTTP clients and servers .It network daemon testing .It a SOCKS or HTTP ProxyCommand for .Xr ssh 1 .It and much, much more .El .Pp The options are as follows: .Bl -tag -width Ds .It Fl 4 Forces .Nm to use IPv4 addresses only. .It Fl 6 Forces .Nm to use IPv6 addresses only. .It Fl D Enable debugging on the socket. .It Fl d Do not attempt to read from stdin. .It Fl F Pass the first connected socket using .Xr sendmsg 2 to stdout and exit. This is useful in conjunction with .Fl X to have .Nm perform connection setup with a proxy but then leave the rest of the connection to another program (e.g.\& .Xr ssh 1 using the .Xr ssh_config 5 .Cm ProxyUseFdpass option). .It Fl h Prints out .Nm help. .It Fl I Ar length Specifies the size of the TCP receive buffer. .It Fl i Ar interval Specifies a delay time interval between lines of text sent and received. Also causes a delay time between connections to multiple ports. .It Fl k Forces .Nm to stay listening for another connection after its current connection is completed. It is an error to use this option without the .Fl l option. When used together with the .Fl u option, the server socket is not connected and it can receive UDP datagrams from multiple hosts. .It Fl l Used to specify that .Nm should listen for an incoming connection rather than initiate a connection to a remote host. It is an error to use this option in conjunction with the .Fl p , .Fl s , or .Fl z options. Additionally, any timeouts specified with the .Fl w option are ignored. .It Fl N .Xr shutdown 2 the network socket after EOF on the input. Some servers require this to finish their work. .It Fl n Do not do any DNS or service lookups on any specified addresses, hostnames or ports. .It Fl O Ar length Specifies the size of the TCP send buffer. .It Fl P Ar proxy_username Specifies a username to present to a proxy server that requires authentication. If no username is specified then authentication will not be attempted. Proxy authentication is only supported for HTTP CONNECT proxies at present. .It Fl p Ar source_port Specifies the source port .Nm should use, subject to privilege restrictions and availability. It is an error to use this option in conjunction with the .Fl l option. .It Fl r Specifies that source and/or destination ports should be chosen randomly instead of sequentially within a range or in the order that the system assigns them. .It Fl S Enables the RFC 2385 TCP MD5 signature option. .It Fl s Ar source Specifies the IP of the interface which is used to send the packets. For .Ux Ns -domain datagram sockets, specifies the local temporary socket file to create and use so that datagrams can be received. It is an error to use this option in conjunction with the .Fl l option. .It Fl T Ar toskeyword Change IPv4 TOS value. .Ar toskeyword may be one of .Ar critical , .Ar inetcontrol , .Ar lowdelay , .Ar netcontrol , .Ar throughput , .Ar reliability , or one of the DiffServ Code Points: .Ar ef , .Ar af11 ... af43 , .Ar cs0 ... cs7 ; or a number in either hex or decimal. .It Fl t Causes .Nm to send RFC 854 DON'T and WON'T responses to RFC 854 DO and WILL requests. This makes it possible to use .Nm to script telnet sessions. .It Fl U Specifies to use .Ux Ns -domain sockets. .It Fl u Use UDP instead of the default option of TCP. For .Ux Ns -domain sockets, use a datagram socket instead of a stream socket. If a .Ux Ns -domain socket is used, a temporary receiving socket is created in .Pa /tmp unless the .Fl s flag is given. .It Fl V Ar rtable Set the routing table to be used. .It Fl v Have .Nm give more verbose output. .It Fl w Ar timeout Connections which cannot be established or are idle timeout after .Ar timeout seconds. The .Fl w flag has no effect on the .Fl l option, i.e.\& .Nm will listen forever for a connection, with or without the .Fl w flag. The default is no timeout. .It Fl X Ar proxy_protocol Requests that .Nm should use the specified protocol when talking to the proxy server. Supported protocols are .Dq 4 (SOCKS v.4), .Dq 5 (SOCKS v.5) and .Dq connect (HTTPS proxy). If the protocol is not specified, SOCKS version 5 is used. .It Xo .Fl x Ar proxy_address Ns Oo : Ns .Ar port Oc .Xc Requests that .Nm should connect to .Ar destination using a proxy at .Ar proxy_address and .Ar port . If .Ar port is not specified, the well-known port for the proxy protocol is used (1080 for SOCKS, 3128 for HTTPS). .It Fl z Specifies that .Nm should just scan for listening daemons, without sending any data to them. It is an error to use this option in conjunction with the .Fl l option. .El .Pp .Ar destination can be a numerical IP address or a symbolic hostname (unless the .Fl n option is given). In general, a destination must be specified, unless the .Fl l option is given (in which case the local host is used). For .Ux Ns -domain sockets, a destination is required and is the socket path to connect to (or listen on if the .Fl l option is given). .Pp .Ar port can be a single integer or a range of ports. Ranges are in the form nn-mm. In general, a destination port must be specified, unless the .Fl U option is given. .Sh CLIENT/SERVER MODEL It is quite simple to build a very basic client/server model using .Nm . On one console, start .Nm listening on a specific port for a connection. For example: .Pp .Dl $ nc -l 1234 .Pp .Nm is now listening on port 1234 for a connection. On a second console .Pq or a second machine , connect to the machine and port being listened on: .Pp .Dl $ nc 127.0.0.1 1234 .Pp There should now be a connection between the ports. Anything typed at the second console will be concatenated to the first, and vice-versa. After the connection has been set up, .Nm does not really care which side is being used as a .Sq server and which side is being used as a .Sq client . The connection may be terminated using an .Dv EOF .Pq Sq ^D . .Sh DATA TRANSFER The example in the previous section can be expanded to build a basic data transfer model. Any information input into one end of the connection will be output to the other end, and input and output can be easily captured in order to emulate file transfer. .Pp Start by using .Nm to listen on a specific port, with output captured into a file: .Pp .Dl $ nc -l 1234 \*(Gt filename.out .Pp Using a second machine, connect to the listening .Nm process, feeding it the file which is to be transferred: .Pp .Dl $ nc -N host.example.com 1234 \*(Lt filename.in .Pp After the file has been transferred, the connection will close automatically. .Sh TALKING TO SERVERS It is sometimes useful to talk to servers .Dq by hand rather than through a user interface. It can aid in troubleshooting, when it might be necessary to verify what data a server is sending in response to commands issued by the client. For example, to retrieve the home page of a web site: .Bd -literal -offset indent $ printf "GET / HTTP/1.0\er\en\er\en" | nc host.example.com 80 .Ed .Pp Note that this also displays the headers sent by the web server. They can be filtered, using a tool such as .Xr sed 1 , if necessary. .Pp More complicated examples can be built up when the user knows the format of requests required by the server. As another example, an email may be submitted to an SMTP server using: .Bd -literal -offset indent $ nc localhost 25 \*(Lt\*(Lt EOF HELO host.example.com MAIL FROM:\*(Ltuser@host.example.com\*(Gt RCPT TO:\*(Ltuser2@host.example.com\*(Gt DATA Body of email. \&. QUIT EOF .Ed .Sh PORT SCANNING It may be useful to know which ports are open and running services on a target machine. The .Fl z flag can be used to tell .Nm to report open ports, rather than initiate a connection. For example: .Bd -literal -offset indent $ nc -z host.example.com 20-30 Connection to host.example.com 22 port [tcp/ssh] succeeded! Connection to host.example.com 25 port [tcp/smtp] succeeded! .Ed .Pp The port range was specified to limit the search to ports 20 \- 30. .Pp Alternatively, it might be useful to know which server software is running, and which versions. This information is often contained within the greeting banners. In order to retrieve these, it is necessary to first make a connection, and then break the connection when the banner has been retrieved. This can be accomplished by specifying a small timeout with the .Fl w flag, or perhaps by issuing a .Qq Dv QUIT command to the server: .Bd -literal -offset indent $ echo "QUIT" | nc host.example.com 20-30 SSH-1.99-OpenSSH_3.6.1p2 Protocol mismatch. 220 host.example.com IMS SMTP Receiver Version 0.84 Ready .Ed .Sh EXAMPLES Open a TCP connection to port 42 of host.example.com, using port 31337 as the source port, with a timeout of 5 seconds: .Pp .Dl $ nc -p 31337 -w 5 host.example.com 42 .Pp Open a UDP connection to port 53 of host.example.com: .Pp .Dl $ nc -u host.example.com 53 .Pp Open a TCP connection to port 42 of host.example.com using 10.1.2.3 as the IP for the local end of the connection: .Pp .Dl $ nc -s 10.1.2.3 host.example.com 42 .Pp Create and listen on a .Ux Ns -domain stream socket: .Pp .Dl $ nc -lU /var/tmp/dsocket .Pp Connect to port 42 of host.example.com via an HTTP proxy at 10.2.3.4, port 8080. This example could also be used by .Xr ssh 1 ; see the .Cm ProxyCommand directive in .Xr ssh_config 5 for more information. .Pp .Dl $ nc -x10.2.3.4:8080 -Xconnect host.example.com 42 .Pp The same example again, this time enabling proxy authentication with username .Dq ruser if the proxy requires it: .Pp .Dl $ nc -x10.2.3.4:8080 -Xconnect -Pruser host.example.com 42 .Sh SEE ALSO .Xr cat 1 , .Xr ssh 1 .Sh AUTHORS Original implementation by *Hobbit* .Aq Mt hobbit@avian.org . .br Rewritten with IPv6 support by .An Eric Jackson Aq Mt ericj@monkey.org . .Sh CAVEATS UDP port scans using the .Fl uz combination of flags will always report success irrespective of the target machine's state. However, in conjunction with a traffic sniffer either on the target machine or an intermediary device, the .Fl uz combination could be useful for communications diagnostics. Note that the amount of UDP traffic generated may be limited either due to hardware resources and/or configuration settings. netcat-openbsd-1.130/netcat.c000066400000000000000000000732471301121717600160620ustar00rootroot00000000000000/* $OpenBSD: netcat.c,v 1.130 2015/07/26 19:12:28 chl Exp $ */ /* * Copyright (c) 2001 Eric Jackson * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * Re-written nc(1) for OpenBSD. Original implementation by * *Hobbit* . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "atomicio.h" #ifndef SUN_LEN #define SUN_LEN(su) \ (sizeof(*(su)) - sizeof((su)->sun_path) + strlen((su)->sun_path)) #endif #define PORT_MAX 65535 #define PORT_MAX_LEN 6 #define UNIX_DG_TMP_SOCKET_SIZE 19 #define POLL_STDIN 0 #define POLL_NETOUT 1 #define POLL_NETIN 2 #define POLL_STDOUT 3 #define BUFSIZE 16384 /* Command Line Options */ int dflag; /* detached, no stdin */ int Fflag; /* fdpass sock to stdout */ unsigned int iflag; /* Interval Flag */ int kflag; /* More than one connect */ int lflag; /* Bind to local port */ int Nflag; /* shutdown() network socket */ int nflag; /* Don't do name look up */ char *Pflag; /* Proxy username */ char *pflag; /* Localport flag */ int rflag; /* Random ports flag */ char *sflag; /* Source Address */ int tflag; /* Telnet Emulation */ int uflag; /* UDP - Default to TCP */ int vflag; /* Verbosity */ int xflag; /* Socks proxy */ int zflag; /* Port Scan Flag */ int Dflag; /* sodebug */ int Iflag; /* TCP receive buffer size */ int Oflag; /* TCP send buffer size */ int Sflag; /* TCP MD5 signature option */ int Tflag = -1; /* IP Type of Service */ int rtableid = -1; int timeout = -1; int family = AF_UNSPEC; char *portlist[PORT_MAX+1]; char *unix_dg_tmp_socket; void atelnet(int, unsigned char *, unsigned int); void build_ports(char *); void help(void); int local_listen(char *, char *, struct addrinfo); void readwrite(int); void fdpass(int nfd) __attribute__((noreturn)); int remote_connect(const char *, const char *, struct addrinfo); int timeout_connect(int, const struct sockaddr *, socklen_t); int socks_connect(const char *, const char *, struct addrinfo, const char *, const char *, struct addrinfo, int, const char *); int udptest(int); int unix_bind(char *); int unix_connect(char *); int unix_listen(char *); void set_common_sockopts(int, int); int map_tos(char *, int *); void report_connect(const struct sockaddr *, socklen_t); void usage(int); ssize_t drainbuf(int, unsigned char *, size_t *); ssize_t fillbuf(int, unsigned char *, size_t *); int main(int argc, char *argv[]) { int ch, s, ret, socksv; char *host, *uport; struct addrinfo hints; struct servent *sv; socklen_t len; struct sockaddr_storage cliaddr; char *proxy; const char *errstr, *proxyhost = "", *proxyport = NULL; struct addrinfo proxyhints; char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; ret = 1; s = 0; socksv = 5; host = NULL; uport = NULL; sv = NULL; signal(SIGPIPE, SIG_IGN); while ((ch = getopt(argc, argv, "46DdFhI:i:klNnO:P:p:rSs:tT:UuV:vw:X:x:z")) != -1) { switch (ch) { case '4': family = AF_INET; break; case '6': family = AF_INET6; break; case 'U': family = AF_UNIX; break; case 'X': if (strcasecmp(optarg, "connect") == 0) socksv = -1; /* HTTP proxy CONNECT */ else if (strcmp(optarg, "4") == 0) socksv = 4; /* SOCKS v.4 */ else if (strcmp(optarg, "5") == 0) socksv = 5; /* SOCKS v.5 */ else errx(1, "unsupported proxy protocol"); break; case 'd': dflag = 1; break; case 'F': Fflag = 1; break; case 'h': help(); break; case 'i': iflag = strtonum(optarg, 0, UINT_MAX, &errstr); if (errstr) errx(1, "interval %s: %s", errstr, optarg); break; case 'k': kflag = 1; break; case 'l': lflag = 1; break; case 'N': Nflag = 1; break; case 'n': nflag = 1; break; case 'P': Pflag = optarg; break; case 'p': pflag = optarg; break; case 'r': rflag = 1; break; case 's': sflag = optarg; break; case 't': tflag = 1; break; case 'u': uflag = 1; break; case 'V': rtableid = (int)strtonum(optarg, 0, RT_TABLEID_MAX, &errstr); if (errstr) errx(1, "rtable %s: %s", errstr, optarg); break; case 'v': vflag = 1; break; case 'w': timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); if (errstr) errx(1, "timeout %s: %s", errstr, optarg); timeout *= 1000; break; case 'x': xflag = 1; if ((proxy = strdup(optarg)) == NULL) err(1, NULL); break; case 'z': zflag = 1; break; case 'D': Dflag = 1; break; case 'I': Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); if (errstr != NULL) errx(1, "TCP receive window %s: %s", errstr, optarg); break; case 'O': Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); if (errstr != NULL) errx(1, "TCP send window %s: %s", errstr, optarg); break; case 'S': Sflag = 1; break; case 'T': errstr = NULL; errno = 0; if (map_tos(optarg, &Tflag)) break; if (strlen(optarg) > 1 && optarg[0] == '0' && optarg[1] == 'x') Tflag = (int)strtol(optarg, NULL, 16); else Tflag = (int)strtonum(optarg, 0, 255, &errstr); if (Tflag < 0 || Tflag > 255 || errstr || errno) errx(1, "illegal tos value %s", optarg); break; default: usage(1); } } argc -= optind; argv += optind; /* Cruft to make sure options are clean, and used properly. */ if (argv[0] && !argv[1] && family == AF_UNIX) { host = argv[0]; uport = NULL; } else if (argv[0] && !argv[1]) { if (!lflag) usage(1); uport = argv[0]; host = NULL; } else if (argv[0] && argv[1]) { host = argv[0]; uport = argv[1]; } else usage(1); if (lflag && sflag) errx(1, "cannot use -s and -l"); if (lflag && pflag) errx(1, "cannot use -p and -l"); if (lflag && zflag) errx(1, "cannot use -z and -l"); if (!lflag && kflag) errx(1, "must use -l with -k"); /* Get name of temporary socket for unix datagram client */ if ((family == AF_UNIX) && uflag && !lflag) { if (sflag) { unix_dg_tmp_socket = sflag; } else { strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", UNIX_DG_TMP_SOCKET_SIZE); if (mktemp(unix_dg_tmp_socket_buf) == NULL) err(1, "mktemp"); unix_dg_tmp_socket = unix_dg_tmp_socket_buf; } } /* Initialize addrinfo structure. */ if (family != AF_UNIX) { memset(&hints, 0, sizeof(struct addrinfo)); hints.ai_family = family; hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; if (nflag) hints.ai_flags |= AI_NUMERICHOST; } if (xflag) { if (uflag) errx(1, "no proxy support for UDP mode"); if (lflag) errx(1, "no proxy support for listen"); if (family == AF_UNIX) errx(1, "no proxy support for unix sockets"); /* XXX IPv6 transport to proxy would probably work */ if (family == AF_INET6) errx(1, "no proxy support for IPv6"); if (sflag) errx(1, "no proxy support for local source address"); proxyhost = strsep(&proxy, ":"); proxyport = proxy; memset(&proxyhints, 0, sizeof(struct addrinfo)); proxyhints.ai_family = family; proxyhints.ai_socktype = SOCK_STREAM; proxyhints.ai_protocol = IPPROTO_TCP; if (nflag) proxyhints.ai_flags |= AI_NUMERICHOST; } if (lflag) { int connfd; ret = 0; if (family == AF_UNIX) { if (uflag) s = unix_bind(host); else s = unix_listen(host); } /* Allow only one connection at a time, but stay alive. */ for (;;) { if (family != AF_UNIX) s = local_listen(host, uport, hints); if (s < 0) err(1, NULL); /* * For UDP and -k, don't connect the socket, let it * receive datagrams from multiple socket pairs. */ if (uflag && kflag) readwrite(s); /* * For UDP and not -k, we will use recvfrom() initially * to wait for a caller, then use the regular functions * to talk to the caller. */ else if (uflag && !kflag) { int rv, plen; char buf[16384]; struct sockaddr_storage z; len = sizeof(z); plen = 2048; rv = recvfrom(s, buf, plen, MSG_PEEK, (struct sockaddr *)&z, &len); if (rv < 0) err(1, "recvfrom"); rv = connect(s, (struct sockaddr *)&z, len); if (rv < 0) err(1, "connect"); if (vflag) report_connect((struct sockaddr *)&z, len); readwrite(s); } else { len = sizeof(cliaddr); connfd = accept(s, (struct sockaddr *)&cliaddr, &len); if (connfd == -1) { /* For now, all errnos are fatal */ err(1, "accept"); } if (vflag) report_connect((struct sockaddr *)&cliaddr, len); readwrite(connfd); close(connfd); } if (family != AF_UNIX) close(s); else if (uflag) { if (connect(s, NULL, 0) < 0) err(1, "connect"); } if (!kflag) break; } } else if (family == AF_UNIX) { ret = 0; if ((s = unix_connect(host)) > 0 && !zflag) { readwrite(s); close(s); } else ret = 1; if (uflag) unlink(unix_dg_tmp_socket); exit(ret); } else { int i = 0; /* Construct the portlist[] array. */ build_ports(uport); /* Cycle through portlist, connecting to each port. */ for (i = 0; portlist[i] != NULL; i++) { if (s) close(s); if (xflag) s = socks_connect(host, portlist[i], hints, proxyhost, proxyport, proxyhints, socksv, Pflag); else s = remote_connect(host, portlist[i], hints); if (s < 0) continue; ret = 0; if (vflag || zflag) { /* For UDP, make sure we are connected. */ if (uflag) { if (udptest(s) == -1) { ret = 1; continue; } } /* Don't look up port if -n. */ if (nflag) sv = NULL; else { sv = getservbyport( ntohs(atoi(portlist[i])), uflag ? "udp" : "tcp"); } fprintf(stderr, "Connection to %s %s port [%s/%s] " "succeeded!\n", host, portlist[i], uflag ? "udp" : "tcp", sv ? sv->s_name : "*"); } if (Fflag) fdpass(s); else if (!zflag) readwrite(s); } } if (s) close(s); exit(ret); } /* * unix_bind() * Returns a unix socket bound to the given path */ int unix_bind(char *path) { struct sockaddr_un sun; int s; /* Create unix domain socket. */ if ((s = socket(AF_UNIX, uflag ? SOCK_DGRAM : SOCK_STREAM, 0)) < 0) return (-1); memset(&sun, 0, sizeof(struct sockaddr_un)); sun.sun_family = AF_UNIX; if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) { close(s); errno = ENAMETOOLONG; return (-1); } if (bind(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) { close(s); return (-1); } return (s); } /* * unix_connect() * Returns a socket connected to a local unix socket. Returns -1 on failure. */ int unix_connect(char *path) { struct sockaddr_un sun; int s; if (uflag) { if ((s = unix_bind(unix_dg_tmp_socket)) < 0) return (-1); } else { if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) return (-1); } (void)fcntl(s, F_SETFD, FD_CLOEXEC); memset(&sun, 0, sizeof(struct sockaddr_un)); sun.sun_family = AF_UNIX; if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) { close(s); errno = ENAMETOOLONG; return (-1); } if (connect(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) { close(s); return (-1); } return (s); } /* * unix_listen() * Create a unix domain socket, and listen on it. */ int unix_listen(char *path) { int s; if ((s = unix_bind(path)) < 0) return (-1); if (listen(s, 5) < 0) { close(s); return (-1); } return (s); } /* * remote_connect() * Returns a socket connected to a remote host. Properly binds to a local * port or source address if needed. Returns -1 on failure. */ int remote_connect(const char *host, const char *port, struct addrinfo hints) { struct addrinfo *res, *res0; int s, error, on = 1; if ((error = getaddrinfo(host, port, &hints, &res))) errx(1, "getaddrinfo: %s", gai_strerror(error)); res0 = res; do { if ((s = socket(res0->ai_family, res0->ai_socktype, res0->ai_protocol)) < 0) continue; if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_RTABLE, &rtableid, sizeof(rtableid)) == -1)) err(1, "setsockopt SO_RTABLE"); /* Bind to a local port or source address if specified. */ if (sflag || pflag) { struct addrinfo ahints, *ares; /* try SO_BINDANY, but don't insist */ setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); memset(&ahints, 0, sizeof(struct addrinfo)); ahints.ai_family = res0->ai_family; ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; ahints.ai_flags = AI_PASSIVE; if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) errx(1, "getaddrinfo: %s", gai_strerror(error)); if (bind(s, (struct sockaddr *)ares->ai_addr, ares->ai_addrlen) < 0) err(1, "bind failed"); freeaddrinfo(ares); } set_common_sockopts(s, res0->ai_family); if (timeout_connect(s, res0->ai_addr, res0->ai_addrlen) == 0) break; else if (vflag) warn("connect to %s port %s (%s) failed", host, port, uflag ? "udp" : "tcp"); close(s); s = -1; } while ((res0 = res0->ai_next) != NULL); freeaddrinfo(res); return (s); } int timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) { struct pollfd pfd; socklen_t optlen; int flags, optval; int ret; if (timeout != -1) { flags = fcntl(s, F_GETFL, 0); if (fcntl(s, F_SETFL, flags | O_NONBLOCK) == -1) err(1, "set non-blocking mode"); } if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { pfd.fd = s; pfd.events = POLLOUT; if ((ret = poll(&pfd, 1, timeout)) == 1) { optlen = sizeof(optval); if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, &optval, &optlen)) == 0) { errno = optval; ret = optval == 0 ? 0 : -1; } } else if (ret == 0) { errno = ETIMEDOUT; ret = -1; } else err(1, "poll failed"); } if (timeout != -1 && fcntl(s, F_SETFL, flags) == -1) err(1, "restoring flags"); return (ret); } /* * local_listen() * Returns a socket listening on a local port, binds to specified source * address. Returns -1 on failure. */ int local_listen(char *host, char *port, struct addrinfo hints) { struct addrinfo *res, *res0; int s, ret, x = 1; int error; /* Allow nodename to be null. */ hints.ai_flags |= AI_PASSIVE; /* * In the case of binding to a wildcard address * default to binding to an ipv4 address. */ if (host == NULL && hints.ai_family == AF_UNSPEC) hints.ai_family = AF_INET; if ((error = getaddrinfo(host, port, &hints, &res))) errx(1, "getaddrinfo: %s", gai_strerror(error)); res0 = res; do { if ((s = socket(res0->ai_family, res0->ai_socktype, res0->ai_protocol)) < 0) continue; if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_RTABLE, &rtableid, sizeof(rtableid)) == -1)) err(1, "setsockopt SO_RTABLE"); ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); if (ret == -1) err(1, NULL); set_common_sockopts(s, res0->ai_family); if (bind(s, (struct sockaddr *)res0->ai_addr, res0->ai_addrlen) == 0) break; close(s); s = -1; } while ((res0 = res0->ai_next) != NULL); if (!uflag && s != -1) { if (listen(s, 1) < 0) err(1, "listen"); } freeaddrinfo(res); return (s); } /* * readwrite() * Loop that polls on the network file descriptor and stdin. */ void readwrite(int net_fd) { struct pollfd pfd[4]; int stdin_fd = STDIN_FILENO; int stdout_fd = STDOUT_FILENO; unsigned char netinbuf[BUFSIZE]; size_t netinbufpos = 0; unsigned char stdinbuf[BUFSIZE]; size_t stdinbufpos = 0; int n, num_fds; ssize_t ret; /* don't read from stdin if requested */ if (dflag) stdin_fd = -1; /* stdin */ pfd[POLL_STDIN].fd = stdin_fd; pfd[POLL_STDIN].events = POLLIN; /* network out */ pfd[POLL_NETOUT].fd = net_fd; pfd[POLL_NETOUT].events = 0; /* network in */ pfd[POLL_NETIN].fd = net_fd; pfd[POLL_NETIN].events = POLLIN; /* stdout */ pfd[POLL_STDOUT].fd = stdout_fd; pfd[POLL_STDOUT].events = 0; while (1) { /* both inputs are gone, buffers are empty, we are done */ if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && stdinbufpos == 0 && netinbufpos == 0) { close(net_fd); return; } /* both outputs are gone, we can't continue */ if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { close(net_fd); return; } /* listen and net in gone, queues empty, done */ if (lflag && pfd[POLL_NETIN].fd == -1 && stdinbufpos == 0 && netinbufpos == 0) { close(net_fd); return; } /* help says -i is for "wait between lines sent". We read and * write arbitrary amounts of data, and we don't want to start * scanning for newlines, so this is as good as it gets */ if (iflag) sleep(iflag); /* poll */ num_fds = poll(pfd, 4, timeout); /* treat poll errors */ if (num_fds == -1) { close(net_fd); err(1, "polling error"); } /* timeout happened */ if (num_fds == 0) return; /* treat socket error conditions */ for (n = 0; n < 4; n++) { if (pfd[n].revents & (POLLERR|POLLNVAL)) { pfd[n].fd = -1; } } /* reading is possible after HUP */ if (pfd[POLL_STDIN].events & POLLIN && pfd[POLL_STDIN].revents & POLLHUP && ! (pfd[POLL_STDIN].revents & POLLIN)) pfd[POLL_STDIN].fd = -1; if (pfd[POLL_NETIN].events & POLLIN && pfd[POLL_NETIN].revents & POLLHUP && ! (pfd[POLL_NETIN].revents & POLLIN)) pfd[POLL_NETIN].fd = -1; if (pfd[POLL_NETOUT].revents & POLLHUP) { if (Nflag) shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); pfd[POLL_NETOUT].fd = -1; } /* if HUP, stop watching stdout */ if (pfd[POLL_STDOUT].revents & POLLHUP) pfd[POLL_STDOUT].fd = -1; /* if no net out, stop watching stdin */ if (pfd[POLL_NETOUT].fd == -1) pfd[POLL_STDIN].fd = -1; /* if no stdout, stop watching net in */ if (pfd[POLL_STDOUT].fd == -1) { if (pfd[POLL_NETIN].fd != -1) shutdown(pfd[POLL_NETIN].fd, SHUT_RD); pfd[POLL_NETIN].fd = -1; } /* try to read from stdin */ if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, &stdinbufpos); /* error or eof on stdin - remove from pfd */ if (ret == 0 || ret == -1) pfd[POLL_STDIN].fd = -1; /* read something - poll net out */ if (stdinbufpos > 0) pfd[POLL_NETOUT].events = POLLOUT; /* filled buffer - remove self from polling */ if (stdinbufpos == BUFSIZE) pfd[POLL_STDIN].events = 0; } /* try to write to network */ if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, &stdinbufpos); if (ret == -1) pfd[POLL_NETOUT].fd = -1; /* buffer empty - remove self from polling */ if (stdinbufpos == 0) pfd[POLL_NETOUT].events = 0; /* buffer no longer full - poll stdin again */ if (stdinbufpos < BUFSIZE) pfd[POLL_STDIN].events = POLLIN; } /* try to read from network */ if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, &netinbufpos); if (ret == -1) pfd[POLL_NETIN].fd = -1; /* eof on net in - remove from pfd */ if (ret == 0) { shutdown(pfd[POLL_NETIN].fd, SHUT_RD); pfd[POLL_NETIN].fd = -1; } /* read something - poll stdout */ if (netinbufpos > 0) pfd[POLL_STDOUT].events = POLLOUT; /* filled buffer - remove self from polling */ if (netinbufpos == BUFSIZE) pfd[POLL_NETIN].events = 0; /* handle telnet */ if (tflag) atelnet(pfd[POLL_NETIN].fd, netinbuf, netinbufpos); } /* try to write to stdout */ if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, &netinbufpos); if (ret == -1) pfd[POLL_STDOUT].fd = -1; /* buffer empty - remove self from polling */ if (netinbufpos == 0) pfd[POLL_STDOUT].events = 0; /* buffer no longer full - poll net in again */ if (netinbufpos < BUFSIZE) pfd[POLL_NETIN].events = POLLIN; } /* stdin gone and queue empty? */ if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { if (pfd[POLL_NETOUT].fd != -1 && Nflag) shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); pfd[POLL_NETOUT].fd = -1; } /* net in gone and queue empty? */ if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { pfd[POLL_STDOUT].fd = -1; } } } ssize_t drainbuf(int fd, unsigned char *buf, size_t *bufpos) { ssize_t n; ssize_t adjust; n = write(fd, buf, *bufpos); /* don't treat EAGAIN, EINTR as error */ if (n == -1 && (errno == EAGAIN || errno == EINTR)) n = -2; if (n <= 0) return n; /* adjust buffer */ adjust = *bufpos - n; if (adjust > 0) memmove(buf, buf + n, adjust); *bufpos -= n; return n; } ssize_t fillbuf(int fd, unsigned char *buf, size_t *bufpos) { size_t num = BUFSIZE - *bufpos; ssize_t n; n = read(fd, buf + *bufpos, num); /* don't treat EAGAIN, EINTR as error */ if (n == -1 && (errno == EAGAIN || errno == EINTR)) n = -2; if (n <= 0) return n; *bufpos += n; return n; } /* * fdpass() * Pass the connected file descriptor to stdout and exit. */ void fdpass(int nfd) { struct msghdr mh; union { struct cmsghdr hdr; char buf[CMSG_SPACE(sizeof(int))]; } cmsgbuf; struct cmsghdr *cmsg; struct iovec iov; char c = '\0'; ssize_t r; struct pollfd pfd; /* Avoid obvious stupidity */ if (isatty(STDOUT_FILENO)) errx(1, "Cannot pass file descriptor to tty"); bzero(&mh, sizeof(mh)); bzero(&cmsgbuf, sizeof(cmsgbuf)); bzero(&iov, sizeof(iov)); mh.msg_control = (caddr_t)&cmsgbuf.buf; mh.msg_controllen = sizeof(cmsgbuf.buf); cmsg = CMSG_FIRSTHDR(&mh); cmsg->cmsg_len = CMSG_LEN(sizeof(int)); cmsg->cmsg_level = SOL_SOCKET; cmsg->cmsg_type = SCM_RIGHTS; *(int *)CMSG_DATA(cmsg) = nfd; iov.iov_base = &c; iov.iov_len = 1; mh.msg_iov = &iov; mh.msg_iovlen = 1; bzero(&pfd, sizeof(pfd)); pfd.fd = STDOUT_FILENO; pfd.events = POLLOUT; for (;;) { r = sendmsg(STDOUT_FILENO, &mh, 0); if (r == -1) { if (errno == EAGAIN || errno == EINTR) { if (poll(&pfd, 1, -1) == -1) err(1, "poll"); continue; } err(1, "sendmsg"); } else if (r != 1) errx(1, "sendmsg: unexpected return value %zd", r); else break; } exit(0); } /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ void atelnet(int nfd, unsigned char *buf, unsigned int size) { unsigned char *p, *end; unsigned char obuf[4]; if (size < 3) return; end = buf + size - 2; for (p = buf; p < end; p++) { if (*p != IAC) continue; obuf[0] = IAC; p++; if ((*p == WILL) || (*p == WONT)) obuf[1] = DONT; else if ((*p == DO) || (*p == DONT)) obuf[1] = WONT; else continue; p++; obuf[2] = *p; if (atomicio(vwrite, nfd, obuf, 3) != 3) warn("Write Error!"); } } /* * build_ports() * Build an array of ports in portlist[], listing each port * that we should try to connect to. */ void build_ports(char *p) { const char *errstr; char *n; int hi, lo, cp; int x = 0; if ((n = strchr(p, '-')) != NULL) { *n = '\0'; n++; /* Make sure the ports are in order: lowest->highest. */ hi = strtonum(n, 1, PORT_MAX, &errstr); if (errstr) errx(1, "port number %s: %s", errstr, n); lo = strtonum(p, 1, PORT_MAX, &errstr); if (errstr) errx(1, "port number %s: %s", errstr, p); if (lo > hi) { cp = hi; hi = lo; lo = cp; } /* Load ports sequentially. */ for (cp = lo; cp <= hi; cp++) { portlist[x] = calloc(1, PORT_MAX_LEN); if (portlist[x] == NULL) err(1, NULL); snprintf(portlist[x], PORT_MAX_LEN, "%d", cp); x++; } /* Randomly swap ports. */ if (rflag) { int y; char *c; for (x = 0; x <= (hi - lo); x++) { y = (arc4random() & 0xFFFF) % (hi - lo); c = portlist[x]; portlist[x] = portlist[y]; portlist[y] = c; } } } else { hi = strtonum(p, 1, PORT_MAX, &errstr); if (errstr) errx(1, "port number %s: %s", errstr, p); portlist[0] = strdup(p); if (portlist[0] == NULL) err(1, NULL); } } /* * udptest() * Do a few writes to see if the UDP port is there. * Fails once PF state table is full. */ int udptest(int s) { int i, ret; for (i = 0; i <= 3; i++) { if (write(s, "X", 1) == 1) ret = 1; else ret = -1; } return (ret); } void set_common_sockopts(int s, int af) { int x = 1; if (Sflag) { if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, &x, sizeof(x)) == -1) err(1, NULL); } if (Dflag) { if (setsockopt(s, SOL_SOCKET, SO_DEBUG, &x, sizeof(x)) == -1) err(1, NULL); } if (Tflag != -1) { int proto, option; if (af == AF_INET6) { proto = IPPROTO_IPV6; option = IPV6_TCLASS; } else { proto = IPPROTO_IP; option = IP_TOS; } if (setsockopt(s, proto, option, &Tflag, sizeof(Tflag)) == -1) err(1, "set IP ToS"); } if (Iflag) { if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, &Iflag, sizeof(Iflag)) == -1) err(1, "set TCP receive buffer size"); } if (Oflag) { if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &Oflag, sizeof(Oflag)) == -1) err(1, "set TCP send buffer size"); } } int map_tos(char *s, int *val) { /* DiffServ Codepoints and other TOS mappings */ const struct toskeywords { const char *keyword; int val; } *t, toskeywords[] = { { "af11", IPTOS_DSCP_AF11 }, { "af12", IPTOS_DSCP_AF12 }, { "af13", IPTOS_DSCP_AF13 }, { "af21", IPTOS_DSCP_AF21 }, { "af22", IPTOS_DSCP_AF22 }, { "af23", IPTOS_DSCP_AF23 }, { "af31", IPTOS_DSCP_AF31 }, { "af32", IPTOS_DSCP_AF32 }, { "af33", IPTOS_DSCP_AF33 }, { "af41", IPTOS_DSCP_AF41 }, { "af42", IPTOS_DSCP_AF42 }, { "af43", IPTOS_DSCP_AF43 }, { "critical", IPTOS_PREC_CRITIC_ECP }, { "cs0", IPTOS_DSCP_CS0 }, { "cs1", IPTOS_DSCP_CS1 }, { "cs2", IPTOS_DSCP_CS2 }, { "cs3", IPTOS_DSCP_CS3 }, { "cs4", IPTOS_DSCP_CS4 }, { "cs5", IPTOS_DSCP_CS5 }, { "cs6", IPTOS_DSCP_CS6 }, { "cs7", IPTOS_DSCP_CS7 }, { "ef", IPTOS_DSCP_EF }, { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, { "lowdelay", IPTOS_LOWDELAY }, { "netcontrol", IPTOS_PREC_NETCONTROL }, { "reliability", IPTOS_RELIABILITY }, { "throughput", IPTOS_THROUGHPUT }, { NULL, -1 }, }; for (t = toskeywords; t->keyword != NULL; t++) { if (strcmp(s, t->keyword) == 0) { *val = t->val; return (1); } } return (0); } void report_connect(const struct sockaddr *sa, socklen_t salen) { char remote_host[NI_MAXHOST]; char remote_port[NI_MAXSERV]; int herr; int flags = NI_NUMERICSERV; if (nflag) flags |= NI_NUMERICHOST; if ((herr = getnameinfo(sa, salen, remote_host, sizeof(remote_host), remote_port, sizeof(remote_port), flags)) != 0) { if (herr == EAI_SYSTEM) err(1, "getnameinfo"); else errx(1, "getnameinfo: %s", gai_strerror(herr)); } fprintf(stderr, "Connection from %s %s " "received!\n", remote_host, remote_port); } void help(void) { usage(0); fprintf(stderr, "\tCommand Summary:\n\ \t-4 Use IPv4\n\ \t-6 Use IPv6\n\ \t-D Enable the debug socket option\n\ \t-d Detach from stdin\n\ \t-F Pass socket fd\n\ \t-h This help text\n\ \t-I length TCP receive buffer length\n\ \t-i secs\t Delay interval for lines sent, ports scanned\n\ \t-k Keep inbound sockets open for multiple connects\n\ \t-l Listen mode, for inbound connects\n\ \t-N Shutdown the network socket after EOF on stdin\n\ \t-n Suppress name/port resolutions\n\ \t-O length TCP send buffer length\n\ \t-P proxyuser\tUsername for proxy authentication\n\ \t-p port\t Specify local port for remote connects\n\ \t-r Randomize remote ports\n\ \t-S Enable the TCP MD5 signature option\n\ \t-s addr\t Local source address\n\ \t-T toskeyword\tSet IP Type of Service\n\ \t-t Answer TELNET negotiation\n\ \t-U Use UNIX domain socket\n\ \t-u UDP mode\n\ \t-V rtable Specify alternate routing table\n\ \t-v Verbose\n\ \t-w secs\t Timeout for connects and final net reads\n\ \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ \t-x addr[:port]\tSpecify proxy address and port\n\ \t-z Zero-I/O mode [used for scanning]\n\ Port numbers can be individual or ranges: lo-hi [inclusive]\n"); exit(1); } void usage(int ret) { fprintf(stderr, "usage: nc [-46DdFhklNnrStUuvz] [-I length] [-i interval] [-O length]\n" "\t [-P proxy_username] [-p source_port] [-s source] [-T ToS]\n" "\t [-V rtable] [-w timeout] [-X proxy_protocol]\n" "\t [-x proxy_address[:port]] [destination] [port]\n"); if (ret) exit(1); } netcat-openbsd-1.130/socks.c000066400000000000000000000231441301121717600157150ustar00rootroot00000000000000/* $OpenBSD: socks.c,v 1.21 2015/03/26 21:19:51 tobias Exp $ */ /* * Copyright (c) 1999 Niklas Hallqvist. All rights reserved. * Copyright (c) 2004, 2005 Damien Miller. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "atomicio.h" #define SOCKS_PORT "1080" #define HTTP_PROXY_PORT "3128" #define HTTP_MAXHDRS 64 #define SOCKS_V5 5 #define SOCKS_V4 4 #define SOCKS_NOAUTH 0 #define SOCKS_NOMETHOD 0xff #define SOCKS_CONNECT 1 #define SOCKS_IPV4 1 #define SOCKS_DOMAIN 3 #define SOCKS_IPV6 4 int remote_connect(const char *, const char *, struct addrinfo); int socks_connect(const char *, const char *, struct addrinfo, const char *, const char *, struct addrinfo, int, const char *); static int decode_addrport(const char *h, const char *p, struct sockaddr *addr, socklen_t addrlen, int v4only, int numeric) { int r; struct addrinfo hints, *res; bzero(&hints, sizeof(hints)); hints.ai_family = v4only ? PF_INET : PF_UNSPEC; hints.ai_flags = numeric ? AI_NUMERICHOST : 0; hints.ai_socktype = SOCK_STREAM; r = getaddrinfo(h, p, &hints, &res); /* Don't fatal when attempting to convert a numeric address */ if (r != 0) { if (!numeric) { errx(1, "getaddrinfo(\"%.64s\", \"%.64s\"): %s", h, p, gai_strerror(r)); } return (-1); } if (addrlen < res->ai_addrlen) { freeaddrinfo(res); errx(1, "internal error: addrlen < res->ai_addrlen"); } memcpy(addr, res->ai_addr, res->ai_addrlen); freeaddrinfo(res); return (0); } static int proxy_read_line(int fd, char *buf, size_t bufsz) { size_t off; for(off = 0;;) { if (off >= bufsz) errx(1, "proxy read too long"); if (atomicio(read, fd, buf + off, 1) != 1) err(1, "proxy read"); /* Skip CR */ if (buf[off] == '\r') continue; if (buf[off] == '\n') { buf[off] = '\0'; break; } off++; } return (off); } static const char * getproxypass(const char *proxyuser, const char *proxyhost) { char prompt[512]; static char pw[256]; snprintf(prompt, sizeof(prompt), "Proxy password for %s@%s: ", proxyuser, proxyhost); if (readpassphrase(prompt, pw, sizeof(pw), RPP_REQUIRE_TTY) == NULL) errx(1, "Unable to read proxy passphrase"); return (pw); } int socks_connect(const char *host, const char *port, struct addrinfo hints __attribute__ ((__unused__)), const char *proxyhost, const char *proxyport, struct addrinfo proxyhints, int socksv, const char *proxyuser) { int proxyfd, r, authretry = 0; size_t hlen, wlen; unsigned char buf[1024]; size_t cnt; struct sockaddr_storage addr; struct sockaddr_in *in4 = (struct sockaddr_in *)&addr; struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&addr; in_port_t serverport; const char *proxypass = NULL; if (proxyport == NULL) proxyport = (socksv == -1) ? HTTP_PROXY_PORT : SOCKS_PORT; /* Abuse API to lookup port */ if (decode_addrport("0.0.0.0", port, (struct sockaddr *)&addr, sizeof(addr), 1, 1) == -1) errx(1, "unknown port \"%.64s\"", port); serverport = in4->sin_port; again: if (authretry++ > 3) errx(1, "Too many authentication failures"); proxyfd = remote_connect(proxyhost, proxyport, proxyhints); if (proxyfd < 0) return (-1); if (socksv == 5) { if (decode_addrport(host, port, (struct sockaddr *)&addr, sizeof(addr), 0, 1) == -1) addr.ss_family = 0; /* used in switch below */ /* Version 5, one method: no authentication */ buf[0] = SOCKS_V5; buf[1] = 1; buf[2] = SOCKS_NOAUTH; cnt = atomicio(vwrite, proxyfd, buf, 3); if (cnt != 3) err(1, "write failed (%zu/3)", cnt); cnt = atomicio(read, proxyfd, buf, 2); if (cnt != 2) err(1, "read failed (%zu/3)", cnt); if (buf[1] == SOCKS_NOMETHOD) errx(1, "authentication method negotiation failed"); switch (addr.ss_family) { case 0: /* Version 5, connect: domain name */ /* Max domain name length is 255 bytes */ hlen = strlen(host); if (hlen > 255) errx(1, "host name too long for SOCKS5"); buf[0] = SOCKS_V5; buf[1] = SOCKS_CONNECT; buf[2] = 0; buf[3] = SOCKS_DOMAIN; buf[4] = hlen; memcpy(buf + 5, host, hlen); memcpy(buf + 5 + hlen, &serverport, sizeof serverport); wlen = 7 + hlen; break; case AF_INET: /* Version 5, connect: IPv4 address */ buf[0] = SOCKS_V5; buf[1] = SOCKS_CONNECT; buf[2] = 0; buf[3] = SOCKS_IPV4; memcpy(buf + 4, &in4->sin_addr, sizeof in4->sin_addr); memcpy(buf + 8, &in4->sin_port, sizeof in4->sin_port); wlen = 10; break; case AF_INET6: /* Version 5, connect: IPv6 address */ buf[0] = SOCKS_V5; buf[1] = SOCKS_CONNECT; buf[2] = 0; buf[3] = SOCKS_IPV6; memcpy(buf + 4, &in6->sin6_addr, sizeof in6->sin6_addr); memcpy(buf + 20, &in6->sin6_port, sizeof in6->sin6_port); wlen = 22; break; default: errx(1, "internal error: silly AF"); } cnt = atomicio(vwrite, proxyfd, buf, wlen); if (cnt != wlen) err(1, "write failed (%zu/%zu)", cnt, wlen); cnt = atomicio(read, proxyfd, buf, 4); if (cnt != 4) err(1, "read failed (%zu/4)", cnt); if (buf[1] != 0) errx(1, "connection failed, SOCKS error %d", buf[1]); switch (buf[3]) { case SOCKS_IPV4: cnt = atomicio(read, proxyfd, buf + 4, 6); if (cnt != 6) err(1, "read failed (%zu/6)", cnt); break; case SOCKS_IPV6: cnt = atomicio(read, proxyfd, buf + 4, 18); if (cnt != 18) err(1, "read failed (%zu/18)", cnt); break; default: errx(1, "connection failed, unsupported address type"); } } else if (socksv == 4) { /* This will exit on lookup failure */ decode_addrport(host, port, (struct sockaddr *)&addr, sizeof(addr), 1, 0); /* Version 4 */ buf[0] = SOCKS_V4; buf[1] = SOCKS_CONNECT; /* connect */ memcpy(buf + 2, &in4->sin_port, sizeof in4->sin_port); memcpy(buf + 4, &in4->sin_addr, sizeof in4->sin_addr); buf[8] = 0; /* empty username */ wlen = 9; cnt = atomicio(vwrite, proxyfd, buf, wlen); if (cnt != wlen) err(1, "write failed (%zu/%zu)", cnt, wlen); cnt = atomicio(read, proxyfd, buf, 8); if (cnt != 8) err(1, "read failed (%zu/8)", cnt); if (buf[1] != 90) errx(1, "connection failed, SOCKS error %d", buf[1]); } else if (socksv == -1) { /* HTTP proxy CONNECT */ /* Disallow bad chars in hostname */ if (strcspn(host, "\r\n\t []:") != strlen(host)) errx(1, "Invalid hostname"); /* Try to be sane about numeric IPv6 addresses */ if (strchr(host, ':') != NULL) { r = snprintf(buf, sizeof(buf), "CONNECT [%s]:%d HTTP/1.0\r\n", host, ntohs(serverport)); } else { r = snprintf(buf, sizeof(buf), "CONNECT %s:%d HTTP/1.0\r\n", host, ntohs(serverport)); } if (r == -1 || (size_t)r >= sizeof(buf)) errx(1, "hostname too long"); r = strlen(buf); cnt = atomicio(vwrite, proxyfd, buf, r); if (cnt != r) err(1, "write failed (%zu/%d)", cnt, r); if (authretry > 1) { char resp[1024]; proxypass = getproxypass(proxyuser, proxyhost); r = snprintf(buf, sizeof(buf), "%s:%s", proxyuser, proxypass); if (r == -1 || (size_t)r >= sizeof(buf) || b64_ntop(buf, strlen(buf), resp, sizeof(resp)) == -1) errx(1, "Proxy username/password too long"); r = snprintf(buf, sizeof(buf), "Proxy-Authorization: " "Basic %s\r\n", resp); if (r == -1 || (size_t)r >= sizeof(buf)) errx(1, "Proxy auth response too long"); r = strlen(buf); if ((cnt = atomicio(vwrite, proxyfd, buf, r)) != r) err(1, "write failed (%zu/%d)", cnt, r); } /* Terminate headers */ if ((cnt = atomicio(vwrite, proxyfd, "\r\n", 2)) != 2) err(1, "write failed (%zu/2)", cnt); /* Read status reply */ proxy_read_line(proxyfd, buf, sizeof(buf)); if (proxyuser != NULL && strncmp(buf, "HTTP/1.0 407 ", 12) == 0) { if (authretry > 1) { fprintf(stderr, "Proxy authentication " "failed\n"); } close(proxyfd); goto again; } else if (strncmp(buf, "HTTP/1.0 200 ", 12) != 0 && strncmp(buf, "HTTP/1.1 200 ", 12) != 0) errx(1, "Proxy error: \"%s\"", buf); /* Headers continue until we hit an empty line */ for (r = 0; r < HTTP_MAXHDRS; r++) { proxy_read_line(proxyfd, buf, sizeof(buf)); if (*buf == '\0') break; } if (*buf != '\0') errx(1, "Too many proxy headers received"); } else errx(1, "Unknown proxy protocol %d", socksv); return (proxyfd); }