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1659 lines
40 KiB
1659 lines
40 KiB
/* $OpenBSD: netcat.c,v 1.126 2014/10/30 16:08:31 tedu Exp $ */ |
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/* |
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* Copyright (c) 2001 Eric Jackson <ericj@monkey.org> |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 3. The name of the author may not be used to endorse or promote products |
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* derived from this software without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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*/ |
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|
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/* |
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* Re-written nc(1) for OpenBSD. Original implementation by |
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* *Hobbit* <hobbit@avian.org>. |
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*/ |
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|
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#include "includes.h" |
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|
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#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <sys/time.h> |
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#include <sys/uio.h> |
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#include <sys/un.h> |
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|
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#include <netinet/in.h> |
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#include <netinet/tcp.h> |
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#include <netinet/ip.h> |
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|
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#include <errno.h> |
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#include <netdb.h> |
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#include <stdarg.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <unistd.h> |
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#include <fcntl.h> |
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#include <limits.h> |
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#include "atomicio.h" |
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|
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#ifdef HAVE_POLL_H |
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#include <poll.h> |
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#else |
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# ifdef HAVE_SYS_POLL_H |
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# include <sys/poll.h> |
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# endif |
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#endif |
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#ifdef HAVE_ERR_H |
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# include <err.h> |
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#endif |
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|
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/* Telnet options from arpa/telnet.h */ |
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#define IAC 255 |
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#define DONT 254 |
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#define DO 253 |
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#define WONT 252 |
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#define WILL 251 |
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|
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#ifndef SUN_LEN |
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#define SUN_LEN(su) \ |
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(sizeof(*(su)) - sizeof((su)->sun_path) + strlen((su)->sun_path)) |
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#endif |
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|
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#define PORT_MAX 65535 |
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#define PORT_MAX_LEN 6 |
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#define UNIX_DG_TMP_SOCKET_SIZE 19 |
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|
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#define POLL_STDIN 0 |
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#define POLL_NETOUT 1 |
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#define POLL_NETIN 2 |
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#define POLL_STDOUT 3 |
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#define BUFSIZE 16384 |
|
|
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/* Command Line Options */ |
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int dflag; /* detached, no stdin */ |
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int Fflag; /* fdpass sock to stdout */ |
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unsigned int iflag; /* Interval Flag */ |
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int kflag; /* More than one connect */ |
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int lflag; /* Bind to local port */ |
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int Nflag; /* shutdown() network socket */ |
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int nflag; /* Don't do name look up */ |
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char *Pflag; /* Proxy username */ |
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char *pflag; /* Localport flag */ |
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int rflag; /* Random ports flag */ |
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char *sflag; /* Source Address */ |
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int tflag; /* Telnet Emulation */ |
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int uflag; /* UDP - Default to TCP */ |
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int vflag; /* Verbosity */ |
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int xflag; /* Socks proxy */ |
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int zflag; /* Port Scan Flag */ |
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int Dflag; /* sodebug */ |
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int Iflag; /* TCP receive buffer size */ |
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int Oflag; /* TCP send buffer size */ |
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int Sflag; /* TCP MD5 signature option */ |
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int Tflag = -1; /* IP Type of Service */ |
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int rtableid = -1; |
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|
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int timeout = -1; |
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int family = AF_UNSPEC; |
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char *portlist[PORT_MAX+1]; |
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char *unix_dg_tmp_socket; |
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|
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void atelnet(int, unsigned char *, unsigned int); |
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void build_ports(char *); |
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void help(void); |
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int local_listen(char *, char *, struct addrinfo); |
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void readwrite(int); |
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void fdpass(int nfd) __attribute__((noreturn)); |
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int remote_connect(const char *, const char *, struct addrinfo); |
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int timeout_connect(int, const struct sockaddr *, socklen_t); |
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int socks_connect(const char *, const char *, struct addrinfo, |
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const char *, const char *, struct addrinfo, int, const char *); |
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int udptest(int); |
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int unix_bind(char *); |
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int unix_connect(char *); |
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int unix_listen(char *); |
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void set_common_sockopts(int); |
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int map_tos(char *, int *); |
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void report_connect(const struct sockaddr *, socklen_t); |
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void usage(int); |
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ssize_t drainbuf(int, unsigned char *, size_t *); |
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ssize_t fillbuf(int, unsigned char *, size_t *); |
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|
|
|
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int |
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main(int argc, char *argv[]) |
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{ |
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int ch, s, ret, socksv; |
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char *host, *uport; |
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struct addrinfo hints; |
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struct servent *sv; |
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socklen_t len; |
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struct sockaddr_storage cliaddr; |
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char *proxy = NULL; |
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const char *errstr, *proxyhost = "", *proxyport = NULL; |
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struct addrinfo proxyhints; |
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char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; |
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|
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ret = 1; |
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s = 0; |
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socksv = 5; |
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host = NULL; |
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uport = NULL; |
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sv = NULL; |
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|
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while ((ch = getopt(argc, argv, |
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"46DdFhI:i:klNnO:P:p:rSs:tT:UuV:vw:X:x:z")) != -1) { |
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switch (ch) { |
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case '4': |
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family = AF_INET; |
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break; |
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case '6': |
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family = AF_INET6; |
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break; |
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case 'U': |
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family = AF_UNIX; |
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break; |
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case 'X': |
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if (strcasecmp(optarg, "connect") == 0) |
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socksv = -1; /* HTTP proxy CONNECT */ |
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else if (strcmp(optarg, "4") == 0) |
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socksv = 4; /* SOCKS v.4 */ |
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else if (strcmp(optarg, "5") == 0) |
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socksv = 5; /* SOCKS v.5 */ |
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else |
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errx(1, "unsupported proxy protocol"); |
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break; |
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case 'd': |
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dflag = 1; |
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break; |
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case 'F': |
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Fflag = 1; |
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break; |
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case 'h': |
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help(); |
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break; |
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case 'i': |
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iflag = strtonum(optarg, 0, UINT_MAX, &errstr); |
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if (errstr) |
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errx(1, "interval %s: %s", errstr, optarg); |
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break; |
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case 'k': |
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kflag = 1; |
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break; |
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case 'l': |
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lflag = 1; |
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break; |
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case 'N': |
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Nflag = 1; |
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break; |
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case 'n': |
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nflag = 1; |
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break; |
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case 'P': |
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Pflag = optarg; |
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break; |
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case 'p': |
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pflag = optarg; |
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break; |
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case 'r': |
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rflag = 1; |
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break; |
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case 's': |
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sflag = optarg; |
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break; |
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case 't': |
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tflag = 1; |
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break; |
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case 'u': |
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uflag = 1; |
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break; |
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#ifdef SO_RTABLE |
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case 'V': |
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rtableid = (int)strtonum(optarg, 0, |
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RT_TABLEID_MAX, &errstr); |
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if (errstr) |
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errx(1, "rtable %s: %s", errstr, optarg); |
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break; |
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#endif |
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case 'v': |
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vflag = 1; |
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break; |
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case 'w': |
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timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); |
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if (errstr) |
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errx(1, "timeout %s: %s", errstr, optarg); |
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timeout *= 1000; |
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break; |
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case 'x': |
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xflag = 1; |
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if ((proxy = strdup(optarg)) == NULL) |
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errx(1, "strdup"); |
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break; |
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case 'z': |
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zflag = 1; |
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break; |
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case 'D': |
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Dflag = 1; |
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break; |
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case 'I': |
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Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); |
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if (errstr != NULL) |
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errx(1, "TCP receive window %s: %s", |
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errstr, optarg); |
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break; |
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case 'O': |
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Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); |
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if (errstr != NULL) |
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errx(1, "TCP send window %s: %s", |
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errstr, optarg); |
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break; |
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case 'S': |
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Sflag = 1; |
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break; |
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case 'T': |
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errstr = NULL; |
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errno = 0; |
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if (map_tos(optarg, &Tflag)) |
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break; |
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if (strlen(optarg) > 1 && optarg[0] == '0' && |
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optarg[1] == 'x') |
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Tflag = (int)strtol(optarg, NULL, 16); |
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else |
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Tflag = (int)strtonum(optarg, 0, 255, |
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&errstr); |
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if (Tflag < 0 || Tflag > 255 || errstr || errno) |
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errx(1, "illegal tos value %s", optarg); |
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break; |
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default: |
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usage(1); |
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} |
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} |
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argc -= optind; |
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argv += optind; |
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|
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/* Cruft to make sure options are clean, and used properly. */ |
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if (argv[0] && !argv[1] && family == AF_UNIX) { |
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host = argv[0]; |
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uport = NULL; |
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} else if (argv[0] && !argv[1]) { |
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if (!lflag) |
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usage(1); |
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uport = argv[0]; |
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host = NULL; |
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} else if (argv[0] && argv[1]) { |
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host = argv[0]; |
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uport = argv[1]; |
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} else |
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usage(1); |
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|
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if (lflag && sflag) |
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errx(1, "cannot use -s and -l"); |
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if (lflag && pflag) |
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errx(1, "cannot use -p and -l"); |
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if (lflag && zflag) |
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errx(1, "cannot use -z and -l"); |
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if (!lflag && kflag) |
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errx(1, "must use -l with -k"); |
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|
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/* Get name of temporary socket for unix datagram client */ |
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if ((family == AF_UNIX) && uflag && !lflag) { |
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if (sflag) { |
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unix_dg_tmp_socket = sflag; |
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} else { |
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strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", |
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UNIX_DG_TMP_SOCKET_SIZE); |
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if (mktemp(unix_dg_tmp_socket_buf) == NULL) |
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err(1, "mktemp"); |
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unix_dg_tmp_socket = unix_dg_tmp_socket_buf; |
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} |
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} |
|
|
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/* Initialize addrinfo structure. */ |
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if (family != AF_UNIX) { |
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memset(&hints, 0, sizeof(struct addrinfo)); |
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hints.ai_family = family; |
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hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; |
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hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; |
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if (nflag) |
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hints.ai_flags |= AI_NUMERICHOST; |
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} |
|
|
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if (xflag) { |
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if (uflag) |
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errx(1, "no proxy support for UDP mode"); |
|
|
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if (lflag) |
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errx(1, "no proxy support for listen"); |
|
|
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if (family == AF_UNIX) |
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errx(1, "no proxy support for unix sockets"); |
|
|
|
/* XXX IPv6 transport to proxy would probably work */ |
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if (family == AF_INET6) |
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errx(1, "no proxy support for IPv6"); |
|
|
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if (sflag) |
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errx(1, "no proxy support for local source address"); |
|
|
|
proxyhost = strsep(&proxy, ":"); |
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proxyport = proxy; |
|
|
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memset(&proxyhints, 0, sizeof(struct addrinfo)); |
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proxyhints.ai_family = family; |
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proxyhints.ai_socktype = SOCK_STREAM; |
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proxyhints.ai_protocol = IPPROTO_TCP; |
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if (nflag) |
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proxyhints.ai_flags |= AI_NUMERICHOST; |
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} |
|
|
|
if (lflag) { |
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int connfd; |
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ret = 0; |
|
|
|
if (family == AF_UNIX) { |
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if (uflag) |
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s = unix_bind(host); |
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else |
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s = unix_listen(host); |
|
} |
|
|
|
/* Allow only one connection at a time, but stay alive. */ |
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for (;;) { |
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if (family != AF_UNIX) |
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s = local_listen(host, uport, hints); |
|
if (s < 0) |
|
err(1, "local_listen"); |
|
/* |
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* For UDP and -k, don't connect the socket, let it |
|
* receive datagrams from multiple socket pairs. |
|
*/ |
|
if (uflag && kflag) |
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readwrite(s); |
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/* |
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* 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; |
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char buf[16384]; |
|
struct sockaddr_storage z; |
|
|
|
len = sizeof(z); |
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plen = 2048; |
|
rv = recvfrom(s, buf, plen, MSG_PEEK, |
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(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_sa; |
|
int s; |
|
|
|
/* Create unix domain socket. */ |
|
if ((s = socket(AF_UNIX, uflag ? SOCK_DGRAM : SOCK_STREAM, |
|
0)) < 0) |
|
return (-1); |
|
|
|
memset(&sun_sa, 0, sizeof(struct sockaddr_un)); |
|
sun_sa.sun_family = AF_UNIX; |
|
|
|
if (strlcpy(sun_sa.sun_path, path, sizeof(sun_sa.sun_path)) >= |
|
sizeof(sun_sa.sun_path)) { |
|
close(s); |
|
errno = ENAMETOOLONG; |
|
return (-1); |
|
} |
|
|
|
if (bind(s, (struct sockaddr *)&sun_sa, SUN_LEN(&sun_sa)) < 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_sa; |
|
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_sa, 0, sizeof(struct sockaddr_un)); |
|
sun_sa.sun_family = AF_UNIX; |
|
|
|
if (strlcpy(sun_sa.sun_path, path, sizeof(sun_sa.sun_path)) >= |
|
sizeof(sun_sa.sun_path)) { |
|
close(s); |
|
errno = ENAMETOOLONG; |
|
return (-1); |
|
} |
|
if (connect(s, (struct sockaddr *)&sun_sa, SUN_LEN(&sun_sa)) < 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; |
|
#if defined(SO_RTABLE) || defined(SO_BINDANY) |
|
int on = 1; |
|
#endif |
|
|
|
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; |
|
|
|
#ifdef SO_RTABLE |
|
if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_RTABLE, |
|
&rtableid, sizeof(rtableid)) == -1)) |
|
err(1, "setsockopt SO_RTABLE"); |
|
#endif |
|
/* Bind to a local port or source address if specified. */ |
|
if (sflag || pflag) { |
|
struct addrinfo ahints, *ares; |
|
|
|
#ifdef SO_BINDANY |
|
/* try SO_BINDANY, but don't insist */ |
|
setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); |
|
#endif |
|
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); |
|
|
|
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 = 0, 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; |
|
|
|
#ifdef SO_RTABLE |
|
if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_RTABLE, |
|
&rtableid, sizeof(rtableid)) == -1)) |
|
err(1, "setsockopt SO_RTABLE"); |
|
#endif |
|
#ifdef SO_REUSEPORT |
|
ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); |
|
if (ret == -1) |
|
err(1, "setsockopt"); |
|
#endif |
|
set_common_sockopts(s); |
|
|
|
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) |
|
{ |
|
#if defined(HAVE_SENDMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)) |
|
struct msghdr msg; |
|
#ifndef HAVE_ACCRIGHTS_IN_MSGHDR |
|
union { |
|
struct cmsghdr hdr; |
|
char buf[CMSG_SPACE(sizeof(int))]; |
|
} cmsgbuf; |
|
struct cmsghdr *cmsg; |
|
#endif |
|
struct iovec vec; |
|
char ch = '\0'; |
|
struct pollfd pfd; |
|
ssize_t r; |
|
|
|
memset(&msg, 0, sizeof(msg)); |
|
#ifdef HAVE_ACCRIGHTS_IN_MSGHDR |
|
msg.msg_accrights = (caddr_t)&nfd; |
|
msg.msg_accrightslen = sizeof(nfd); |
|
#else |
|
memset(&cmsgbuf, 0, sizeof(cmsgbuf)); |
|
msg.msg_control = (caddr_t)&cmsgbuf.buf; |
|
msg.msg_controllen = sizeof(cmsgbuf.buf); |
|
cmsg = CMSG_FIRSTHDR(&msg); |
|
cmsg->cmsg_len = CMSG_LEN(sizeof(int)); |
|
cmsg->cmsg_level = SOL_SOCKET; |
|
cmsg->cmsg_type = SCM_RIGHTS; |
|
*(int *)CMSG_DATA(cmsg) = nfd; |
|
#endif |
|
|
|
vec.iov_base = &ch; |
|
vec.iov_len = 1; |
|
msg.msg_iov = &vec; |
|
msg.msg_iovlen = 1; |
|
|
|
bzero(&pfd, sizeof(pfd)); |
|
pfd.fd = STDOUT_FILENO; |
|
for (;;) { |
|
r = sendmsg(STDOUT_FILENO, &msg, 0); |
|
if (r == -1) { |
|
if (errno == EAGAIN || errno == EINTR) { |
|
pfd.events = POLLOUT; |
|
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); |
|
#else |
|
errx(1, "%s: file descriptor passing not supported", __func__); |
|
#endif |
|
} |
|
|
|
/* 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) |
|
errx(1, "calloc"); |
|
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) |
|
errx(1, "strdup"); |
|
} |
|
} |
|
|
|
/* |
|
* 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 x = 1; |
|
|
|
#ifdef TCP_MD5SIG |
|
if (Sflag) { |
|
if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, |
|
&x, sizeof(x)) == -1) |
|
err(1, "setsockopt"); |
|
} |
|
#endif |
|
if (Dflag) { |
|
if (setsockopt(s, SOL_SOCKET, SO_DEBUG, |
|
&x, sizeof(x)) == -1) |
|
err(1, "setsockopt"); |
|
} |
|
if (Tflag != -1) { |
|
if (setsockopt(s, IPPROTO_IP, IP_TOS, |
|
&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); |
|
} |
|
|
|
/* *** src/usr.bin/nc/socks.c *** */ |
|
|
|
|
|
/* $OpenBSD: socks.c,v 1.20 2012/03/08 09:56:28 espie 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 <sys/types.h> |
|
#include <sys/socket.h> |
|
#include <netinet/in.h> |
|
#include <arpa/inet.h> |
|
|
|
#include <errno.h> |
|
#include <netdb.h> |
|
#include <stdio.h> |
|
#include <stdlib.h> |
|
#include <string.h> |
|
#include <unistd.h> |
|
#include <resolv.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 = 0; |
|
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 != (size_t)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)) != (size_t)r) |
|
err(1, "write failed (%zu/%d)", cnt, r); |
|
} |
|
|
|
/* Terminate headers */ |
|
if ((r = atomicio(vwrite, proxyfd, "\r\n", 2)) != 2) |
|
err(1, "write failed (2/%d)", r); |
|
|
|
/* 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); |
|
} |
|
|
|
|