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nmap/ncat/ncat_main.c
david ed2ba4e168 Copy nping, nsock, nbase, zenmap, ncat from their homes in /. 
If you have trouble updating after this revision you need to follow
these instructions. You have probably just seen an error like this:

svn: URL 'svn://svn.insecure.org/nping' of existing directory 'nping'
does not match expected URL 'svn://svn.insecure.org/nmap/nping'

This is caused by the replacement of SVN externals.

Here's what you need to do. First, save any local changes you might have
in the nping, nsock, nbase, ncat, and zenmap directories. (For example
by running "cd nping; svn diff > ../nping.diff".) If you don't have any
local changes you can skip this step.

Then run these commands:

rm -rf nping/ nsock/ nbase/ ncat/ zenmap/
svn update
svn cleanup

If all else fails, you can just delete your whole working directory and
check out anew:

svn co --username guest --password "" svn://svn.insecure.org/nmap

There may be further discussion in the mailing list thread at
http://seclists.org/nmap-dev/2011/q4/303.
2011-11-16 21:49:44 +00:00

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/***************************************************************************
* ncat_main.c -- main function: option parsing and checking, dispatching *
* to mode-specific functions. *
***********************IMPORTANT NMAP LICENSE TERMS************************
* *
* The Nmap Security Scanner is (C) 1996-2011 Insecure.Com LLC. Nmap is *
* also a registered trademark of Insecure.Com LLC. This program is free *
* software; you may redistribute and/or modify it under the terms of the *
* GNU General Public License as published by the Free Software *
* Foundation; Version 2 with the clarifications and exceptions described *
* below. This guarantees your right to use, modify, and redistribute *
* this software under certain conditions. If you wish to embed Nmap *
* technology into proprietary software, we sell alternative licenses *
* (contact sales@insecure.com). Dozens of software vendors already *
* license Nmap technology such as host discovery, port scanning, OS *
* detection, and version detection. *
* *
* Note that the GPL places important restrictions on "derived works", yet *
* it does not provide a detailed definition of that term. To avoid *
* misunderstandings, we consider an application to constitute a *
* "derivative work" for the purpose of this license if it does any of the *
* following: *
* o Integrates source code from Nmap *
* o Reads or includes Nmap copyrighted data files, such as *
* nmap-os-db or nmap-service-probes. *
* o Executes Nmap and parses the results (as opposed to typical shell or *
* execution-menu apps, which simply display raw Nmap output and so are *
* not derivative works.) *
* o Integrates/includes/aggregates Nmap into a proprietary executable *
* installer, such as those produced by InstallShield. *
* o Links to a library or executes a program that does any of the above *
* *
* The term "Nmap" should be taken to also include any portions or derived *
* works of Nmap. This list is not exclusive, but is meant to clarify our *
* interpretation of derived works with some common examples. Our *
* interpretation applies only to Nmap--we don't speak for other people's *
* GPL works. *
* *
* If you have any questions about the GPL licensing restrictions on using *
* Nmap in non-GPL works, we would be happy to help. As mentioned above, *
* we also offer alternative license to integrate Nmap into proprietary *
* applications and appliances. These contracts have been sold to dozens *
* of software vendors, and generally include a perpetual license as well *
* as providing for priority support and updates as well as helping to *
* fund the continued development of Nmap technology. Please email *
* sales@insecure.com for further information. *
* *
* As a special exception to the GPL terms, Insecure.Com LLC grants *
* permission to link the code of this program with any version of the *
* OpenSSL library which is distributed under a license identical to that *
* listed in the included docs/licenses/OpenSSL.txt file, and distribute *
* linked combinations including the two. You must obey the GNU GPL in all *
* respects for all of the code used other than OpenSSL. If you modify *
* this file, you may extend this exception to your version of the file, *
* but you are not obligated to do so. *
* *
* If you received these files with a written license agreement or *
* contract stating terms other than the terms above, then that *
* alternative license agreement takes precedence over these comments. *
* *
* Source is provided to this software because we believe users have a *
* right to know exactly what a program is going to do before they run it. *
* This also allows you to audit the software for security holes (none *
* have been found so far). *
* *
* Source code also allows you to port Nmap to new platforms, fix bugs, *
* and add new features. You are highly encouraged to send your changes *
* to nmap-dev@insecure.org for possible incorporation into the main *
* distribution. By sending these changes to Fyodor or one of the *
* Insecure.Org development mailing lists, it is assumed that you are *
* offering the Nmap Project (Insecure.Com LLC) the unlimited, *
* non-exclusive right to reuse, modify, and relicense the code. Nmap *
* will always be available Open Source, but this is important because the *
* inability to relicense code has caused devastating problems for other *
* Free Software projects (such as KDE and NASM). We also occasionally *
* relicense the code to third parties as discussed above. If you wish to *
* specify special license conditions of your contributions, just say so *
* when you send them. *
* *
* This program is distributed in the hope that it will be useful, but *
* WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* General Public License v2.0 for more details at *
* http://www.gnu.org/licenses/gpl-2.0.html , or in the COPYING file *
* included with Nmap. *
* *
***************************************************************************/
/* $Id$ */
#include "nsock.h"
#include "ncat.h"
#include "util.h"
#include "sys_wrap.h"
#include <getopt.h>
#ifndef WIN32
#include <unistd.h>
#endif
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#ifndef WIN32
#include <netdb.h>
#endif
#include <fcntl.h>
#ifdef HAVE_OPENSSL
#include <openssl/ssl.h>
#include <openssl/err.h>
#endif
static int ncat_connect_mode(void);
static int ncat_listen_mode(void);
/* Determines if it's parsing HTTP or SOCKS by looking at defport */
static void parseproxy(char *str, struct sockaddr_storage *ss, unsigned short defport)
{
char *c = strrchr(str, ':'), *ptr;
int httpproxy = (defport == DEFAULT_PROXY_PORT);
unsigned short portno;
size_t sslen;
ptr = str;
if (c)
*c = 0;
if (c && strlen((c + 1)))
portno = (unsigned short) atoi(c + 1);
else
portno = defport;
if (!resolve(ptr, portno, ss, &sslen, o.af)) {
loguser("Could not resolve proxy \"%s\".\n", ptr);
if (o.af == AF_INET6 && httpproxy)
loguser("Did you specify the port number? It's required for IPv6.\n");
exit(EXIT_FAILURE);
}
}
/* These functions implement a simple linked list to hold allow/deny
specifications until the end of option parsing. */
struct host_list_node {
/* If false, then spec is the name of a file containing host patterns. */
int is_filename;
char *spec;
struct host_list_node *next;
};
static void host_list_add_spec(struct host_list_node **list, char *spec)
{
struct host_list_node *node = (struct host_list_node *) safe_malloc(sizeof(*node));
node->is_filename = 0;
node->spec = spec;
node->next = *list;
*list = node;
}
static void host_list_add_filename(struct host_list_node **list, char *filename)
{
struct host_list_node *node = (struct host_list_node *) safe_malloc(sizeof(*node));
node->is_filename = 1;
node->spec = filename;
node->next = *list;
*list = node;
}
static void host_list_free(struct host_list_node *list)
{
struct host_list_node *next;
for ( ; list != NULL; list = next) {
next = list->next;
free(list);
}
}
static void host_list_to_set(struct addrset *set, struct host_list_node *list)
{
struct host_list_node *node;
for (node = list; node != NULL; node = node->next) {
if (node->is_filename) {
FILE *fd;
fd = fopen(node->spec, "r");
if (fd == NULL)
bye("can't open %s: %s.", node->spec, strerror(errno));
if (!addrset_add_file(set, fd, o.af, !o.nodns))
bye("error in hosts file %s.", node->spec);
fclose(fd);
} else {
char *spec, *commalist;
commalist = node->spec;
while ((spec = strtok(commalist, ",")) != NULL) {
commalist = NULL;
if (!addrset_add_spec(set, spec, o.af, !o.nodns))
bye("error in host specification \"%s\".", node->spec);
}
}
}
}
static void print_banner(void)
{
loguser("Version %s ( %s )\n", NCAT_VERSION, NCAT_URL);
}
int main(int argc, char *argv[])
{
/* We have to buffer the lists of hosts to allow and deny until after option
parsing is done. Adding hosts to an addrset can require name resolution,
which may differ as a result of options like -n and -6. */
struct host_list_node *allow_host_list = NULL;
struct host_list_node *deny_host_list = NULL;
int srcport = -1;
char *source = NULL;
char *proxyaddr = NULL;
struct option long_options[] = {
{"4", no_argument, NULL, '4'},
{"6", no_argument, NULL, '6'},
{"crlf", no_argument, NULL, 'C'},
{"g", required_argument, NULL, 'g'},
{"G", required_argument, NULL, 'G'},
{"exec", required_argument, NULL, 'e'},
{"sh-exec", required_argument, NULL, 'c'},
{"max-conns", required_argument, NULL, 'm'},
{"help", no_argument, NULL, 'h'},
{"delay", required_argument, NULL, 'd'},
{"listen", no_argument, NULL, 'l'},
{"output", required_argument, NULL, 'o'},
{"hex-dump", required_argument, NULL, 'x'},
{"append-output", no_argument, NULL, 0},
{"idle-timeout", required_argument, NULL, 'i'},
{"keep-open", no_argument, NULL, 'k'},
{"recv-only", no_argument, &o.recvonly, 1},
{"source-port", required_argument, NULL, 'p'},
{"source", required_argument, NULL, 's'},
{"send-only", no_argument, &o.sendonly, 1},
{"broker", no_argument, NULL, 0},
{"chat", no_argument, NULL, 0},
{"talk", no_argument, NULL, 0},
{"deny", required_argument, NULL, 0},
{"denyfile", required_argument, NULL, 0},
{"allow", required_argument, NULL, 0},
{"allowfile", required_argument, NULL, 0},
{"telnet", no_argument, NULL, 't'},
{"udp", no_argument, NULL, 'u'},
{"sctp", no_argument, &o.sctp, 1},
{"version", no_argument, NULL, 0},
{"verbose", no_argument, NULL, 'v'},
{"wait", required_argument, NULL, 'w'},
{"nodns", no_argument, NULL, 'n'},
{"proxy", required_argument, NULL, 0},
{"proxy-type", required_argument, NULL, 0},
{"proxy-auth", required_argument, NULL, 0},
#ifdef HAVE_OPENSSL
{"ssl", no_argument, &o.ssl, 1},
{"ssl-cert", required_argument, NULL, 0},
{"ssl-key", required_argument, NULL, 0},
{"ssl-verify", no_argument, NULL, 0},
{"ssl-trustfile", required_argument, NULL, 0},
#endif
{0, 0, 0, 0}
};
gettimeofday(&start_time, NULL);
/* Set default options. */
options_init();
#ifdef WIN32
windows_init();
#endif
while (1) {
/* handle command line arguments */
int option_index;
int c = getopt_long(argc, argv, "46Cc:e:g:G:i:km:hp:d:lo:x:ts:uvw:n",
long_options, &option_index);
/* That's the end of the options. */
if (c == -1)
break;
switch (c) {
case '4':
o.af = AF_INET;
break;
case '6':
#ifdef HAVE_IPV6
o.af = AF_INET6;
#else
bye("-6 chosen when IPv6 wasn't compiled in.");
#endif
break;
case 'C':
o.crlf = 1;
break;
case 'c':
o.cmdexec = optarg;
o.shellexec = 1;
break;
case 'e':
o.cmdexec = optarg;
break;
case 'g': {
char *a = strtok(optarg, ",");
do {
union sockaddr_u addr;
size_t sslen;
if (!resolve(a, 0, &addr.storage, &sslen, AF_INET))
bye("Sorry, could not resolve source route hop %s.", a);
o.srcrtes[o.numsrcrtes] = addr.in.sin_addr;
} while (o.numsrcrtes++ <= 8 && (a = strtok(NULL, ",")));
if (o.numsrcrtes > 8)
bye("Sorry, you gave too many source route hops.");
break;
}
case 'G':
o.srcrteptr = atoi(optarg);
if (o.srcrteptr < 4 || (o.srcrteptr % 4) || o.srcrteptr > 28)
bye("Invalid source-route hop pointer %d.", o.srcrteptr);
break;
case 'k':
o.keepopen = 1;
break;
case 'm':
o.conn_limit = atoi(optarg);
break;
case 'd':
o.linedelay = tval2msecs(optarg);
if (o.linedelay <= 0)
bye("Invalid -d delay (must be greater than 0).", optarg);
if (o.linedelay >= 100 * 1000 && tval_unit(optarg) == NULL)
bye("Since April 2010, the default unit for -d is seconds, so your time of \"%s\" is %.1f minutes. Use \"%sms\" for %g milliseconds.", optarg, o.linedelay / 1000.0 / 60, optarg, o.linedelay / 1000.0);
break;
case 'o':
o.normlog = optarg;
break;
case 'x':
o.hexlog = optarg;
break;
case 'p':
srcport = atoi(optarg);
if (srcport < 0 || srcport > 0xffff)
bye("Invalid source port %d.", srcport);
break;
case 'i':
o.idletimeout = tval2msecs(optarg);
if (o.idletimeout <= 0)
bye("Invalid -i timeout (must be greater than 0).");
if (o.linedelay >= 100 * 1000 && tval_unit(optarg) == NULL)
bye("Since April 2010, the default unit for -i is seconds, so your time of \"%s\" is %.1f minutes. Use \"%sms\" for %g milliseconds.", optarg, o.linedelay / 1000.0 / 60, optarg, o.linedelay / 1000.0);
break;
case 's':
source = optarg;
break;
case 'l':
o.listen = 1;
break;
case 'u':
o.udp = 1;
break;
case 'v':
/* One -v activites verbose, after that it's debugging. */
if (o.verbose == 0)
o.verbose++;
else
o.debug++;
break;
case 'n':
o.nodns = 1;
break;
case 'w':
o.conntimeout = tval2msecs(optarg);
if (o.conntimeout <= 0)
bye("Invalid -w timeout (must be greater than 0).");
if (o.linedelay >= 100 * 1000 && tval_unit(optarg) == NULL)
bye("Since April 2010, the default unit for -w is seconds, so your time of \"%s\" is %.1f minutes. Use \"%sms\" for %g milliseconds.", optarg, o.linedelay / 1000.0 / 60, optarg, o.linedelay / 1000.0);
break;
case 't':
o.telnet = 1;
break;
case 0:
if (strcmp(long_options[option_index].name, "version") == 0) {
print_banner();
exit(EXIT_SUCCESS);
}
else if (strcmp(long_options[option_index].name, "proxy") == 0)
{
if (proxyaddr)
bye("You can't specify more than one --proxy.");
proxyaddr = Strdup(optarg);
}
else if (strcmp(long_options[option_index].name, "proxy-type") == 0)
{
if (o.proxytype)
bye("You can't specify more than one --proxy-type.");
o.proxytype = Strdup(optarg);
}
else if (strcmp(long_options[option_index].name, "proxy-auth") == 0)
{
if (o.proxy_auth)
bye("You can't specify more than one --proxy-auth.");
o.proxy_auth = Strdup(optarg);
}
else if (strcmp(long_options[option_index].name, "broker") == 0)
{
o.broker = 1;
/* --broker implies --listen. */
o.listen = 1;
}
else if (strcmp(long_options[option_index].name, "chat") == 0
|| strcmp(long_options[option_index].name, "talk") == 0)
{
/* --talk is an older name for --chat. */
o.chat = 1;
/* --chat implies --broker. */
o.broker = 1;
}
else if (strcmp(long_options[option_index].name, "allow") == 0)
{
o.allow = 1;
host_list_add_spec(&allow_host_list, optarg);
}
else if (strcmp(long_options[option_index].name, "allowfile") == 0)
{
o.allow = 1;
host_list_add_filename(&allow_host_list, optarg);
}
else if (strcmp(long_options[option_index].name, "deny") == 0)
{
host_list_add_spec(&deny_host_list, optarg);
}
else if (strcmp(long_options[option_index].name, "denyfile") == 0)
{
host_list_add_filename(&deny_host_list, optarg);
}
else if (strcmp(long_options[option_index].name, "append-output") == 0)
{
o.append = 1;
}
#ifdef HAVE_OPENSSL
else if (strcmp(long_options[option_index].name, "ssl-cert") == 0)
{
o.ssl = 1;
o.sslcert = Strdup(optarg);
}
else if (strcmp(long_options[option_index].name, "ssl-key") == 0)
{
o.ssl = 1;
o.sslkey = Strdup(optarg);
}
else if (strcmp(long_options[option_index].name, "ssl-verify") == 0)
{
o.sslverify = 1;
o.ssl = 1;
}
else if (strcmp(long_options[option_index].name, "ssl-trustfile") == 0)
{
o.ssl = 1;
if (o.ssltrustfile != NULL)
bye("The --ssl-trustfile option may be given only once.");
o.ssltrustfile = Strdup(optarg);
/* If they list a trustfile assume they want certificate
verification. */
o.sslverify = 1;
}
#endif
break;
case 'h':
printf("%s %s ( %s )\n", NCAT_NAME, NCAT_VERSION, NCAT_URL);
printf(
"Usage: ncat [options] [hostname] [port]\n"
"\n"
"Options taking a time assume seconds. Append 'ms' for milliseconds,\n"
"'s' for seconds, 'm' for minutes, or 'h' for hours (e.g. 500ms).\n"
" -4 Use IPv4 only\n"
" -6 Use IPv6 only\n"
" -C, --crlf Use CRLF for EOL sequence\n"
" -c, --sh-exec <command> Executes the given command via /bin/sh\n"
" -e, --exec <command> Executes the given command\n"
" -g hop1[,hop2,...] Loose source routing hop points (8 max)\n"
" -G <n> Loose source routing hop pointer (4, 8, 12, ...)\n"
" -m, --max-conns <n> Maximum <n> simultaneous connections\n"
" -h, --help Display this help screen\n"
" -d, --delay <time> Wait between read/writes\n"
" -o, --output <filename> Dump session data to a file\n"
" -x, --hex-dump <filename> Dump session data as hex to a file\n"
" -i, --idle-timeout <time> Idle read/write timeout\n"
" -p, --source-port port Specify source port to use\n"
" -s, --source addr Specify source address to use (doesn't affect -l)\n"
" -l, --listen Bind and listen for incoming connections\n"
" -k, --keep-open Accept multiple connections in listen mode\n"
" -n, --nodns Do not resolve hostnames via DNS\n"
" -t, --telnet Answer Telnet negotiations\n"
" -u, --udp Use UDP instead of default TCP\n"
" --sctp Use SCTP instead of default TCP\n"
" -v, --verbose Set verbosity level (can be used up to 3 times)\n"
" -w, --wait <time> Connect timeout\n"
" --append-output Append rather than clobber specified output files\n"
" --send-only Only send data, ignoring received; quit on EOF\n"
" --recv-only Only receive data, never send anything\n"
" --allow Allow only given hosts to connect to Ncat\n"
" --allowfile A file of hosts allowed to connect to Ncat\n"
" --deny Deny given hosts from connecting to Ncat\n"
" --denyfile A file of hosts denied from connecting to Ncat\n"
" --broker Enable Ncat's connection brokering mode\n"
" --chat Start a simple Ncat chat server\n"
" --proxy <addr[:port]> Specify address of host to proxy through\n"
" --proxy-type <type> Specify proxy type (\"http\" or \"socks4\")\n"
" --proxy-auth <auth> Authenticate with HTTP or SOCKS proxy server\n"
#ifdef HAVE_OPENSSL
" --ssl Connect or listen with SSL\n"
" --ssl-cert Specify SSL certificate file (PEM) for listening\n"
" --ssl-key Specify SSL private key (PEM) for listening\n"
" --ssl-verify Verify trust and domain name of certificates\n"
" --ssl-trustfile PEM file containing trusted SSL certificates\n"
#endif
" --version Display Ncat's version information and exit\n"
"\n"
"See the ncat(1) manpage for full options, descriptions and usage examples\n"
);
exit(EXIT_SUCCESS);
case '?':
/* Consider unrecognised parameters/arguments as fatal. */
bye("Try `--help' or man(1) ncat for more information, usage options and help.");
default:
/* We consider an unrecognised option fatal. */
bye("Unrecognised option.");
}
}
if (o.normlog)
o.normlogfd = ncat_openlog(o.normlog, o.append);
if (o.hexlog)
o.hexlogfd = ncat_openlog(o.hexlog, o.append);
if (o.verbose)
print_banner();
if (o.debug)
nbase_set_log(loguser, logdebug);
else
nbase_set_log(loguser, NULL);
/* Will be AF_INET or AF_INET6 when valid */
memset(&targetss.storage, 0, sizeof(targetss.storage));
targetss.storage.ss_family = AF_UNSPEC;
httpconnect.storage = socksconnect.storage = srcaddr.storage = targetss.storage;
/* Clear the listenaddrs array */
int i;
for (i = 0; i < NUM_LISTEN_ADDRS; i++) {
listenaddrs[i].storage = targetss.storage;
}
if (proxyaddr) {
if (!o.proxytype)
o.proxytype = Strdup("http");
if (!strcmp(o.proxytype, "http")) {
/* Parse HTTP proxy address and temporarily store it in httpconnect. If
* the proxy server is given as an IPv6 address (not hostname), the port
* number MUST be specified as well or parsing will break (due to the
* colons in the IPv6 address and host:port separator).
*/
parseproxy(proxyaddr, &httpconnect.storage, DEFAULT_PROXY_PORT);
} else if (!strcmp(o.proxytype, "socks4") || !strcmp(o.proxytype, "4")) {
/* Parse SOCKS proxy address and temporarily store it in socksconnect */
parseproxy(proxyaddr, &socksconnect.storage, DEFAULT_SOCKS4_PORT);
} else {
bye("Invalid proxy type \"%s\".", o.proxytype);
}
free(o.proxytype);
free(proxyaddr);
} else {
if (o.proxytype) {
if (!o.listen)
bye("Proxy type (--proxy-type) specified without proxy address (--proxy).");
if (strcmp(o.proxytype, "http"))
bye("Invalid proxy type \"%s\".", o.proxytype);
}
}
/* Default port */
o.portno = DEFAULT_NCAT_PORT;
/* Resolve the given source address */
if (source) {
if (o.listen)
bye("-l and -s are incompatible. Specify the address and port to bind to like you would a host to connect to.");
if (!resolve(source, 0, &srcaddr.storage, &srcaddrlen, o.af))
bye("Could not resolve source address %s.", source);
}
host_list_to_set(&o.allowset, allow_host_list);
host_list_free(allow_host_list);
host_list_to_set(&o.denyset, deny_host_list);
host_list_free(deny_host_list);
if (optind == argc) {
/* Listen defaults to any address and DEFAULT_NCAT_PORT */
if (!o.listen)
bye("You must specify a host to connect to.");
} else {
/* Resolve hostname if we're given one */
if (strspn(argv[optind], "0123456789") != strlen(argv[optind])) {
o.target = argv[optind];
/* resolve hostname */
if (!resolve(o.target, 0, &targetss.storage, &targetsslen, o.af))
bye("Could not resolve hostname %s.", o.target);
optind++;
} else {
if (!o.listen)
bye("You must specify a host to connect to.");
}
}
/* Whatever's left is the port number; there should be at most one. */
if (optind + 1 < argc || (o.listen && srcport != -1 && optind + 1 == argc)) {
loguser("Got more than one port specification:");
if (o.listen && srcport != -1)
loguser_noprefix(" %d", srcport);
for (; optind < argc; optind++)
loguser_noprefix(" %s", argv[optind]);
loguser_noprefix(". QUITTING.\n");
exit(2);
} else if (optind + 1 == argc) {
long long_port;
errno = 0;
long_port = strtol(argv[optind], NULL, 10);
if (errno != 0 || long_port <= 0 || long_port > 65535)
bye("Invalid port number \"%s\".", argv[optind]);
o.portno = (unsigned short) long_port;
}
if (o.af == AF_INET)
targetss.in.sin_port = htons(o.portno);
#ifdef HAVE_IPV6
else
targetss.in6.sin6_port = htons(o.portno);
#endif
if (srcport != -1) {
if (o.listen) {
/* Treat "ncat -l -p <port>" the same as "ncat -l <port>" for nc
compatibility. */
o.portno = srcport;
} else {
if (srcaddr.storage.ss_family == AF_UNSPEC) {
/* We have a source port but not an explicit source address;
fill in an unspecified address of the same family as the
target. */
srcaddr.storage.ss_family = targetss.storage.ss_family;
if (srcaddr.storage.ss_family == AF_INET)
srcaddr.in.sin_addr.s_addr = INADDR_ANY;
else if (srcaddr.storage.ss_family == AF_INET6)
srcaddr.in6.sin6_addr = in6addr_any;
}
if (srcaddr.storage.ss_family == AF_INET)
srcaddr.in.sin_port = htons(srcport);
#ifdef HAVE_IPV6
else
srcaddr.in6.sin6_port = htons(srcport);
#endif
}
}
/* Since the host we're actually *connecting* to is the proxy server, we
* need to reverse these address structures to avoid any further confusion
*/
if (httpconnect.storage.ss_family != AF_UNSPEC) {
union sockaddr_u tmp = targetss;
targetss = httpconnect;
httpconnect = tmp;
} else if (socksconnect.storage.ss_family != AF_UNSPEC) {
union sockaddr_u tmp = targetss;
targetss = socksconnect;
socksconnect = tmp;
}
if (o.udp) {
/* Don't allow a false sense of security if someone tries SSL over UDP. */
if (o.ssl)
bye("UDP mode does not support SSL.");
if (o.keepopen && o.cmdexec == NULL)
bye("UDP mode does not support the -k or --keep-open options, except with --exec or --sh-exec.");
if (o.broker)
bye("UDP mode does not support connection brokering.\n\
If this feature is important to you, write nmap-dev@insecure.org with a\n\
description of how you intend to use it, as an aid to deciding how UDP\n\
connection brokering should work.");
}
/* Do whatever is necessary to receive \n for line endings on input from
the console. A no-op on Unix. */
set_lf_mode();
if (o.listen)
return ncat_listen_mode();
else
return ncat_connect_mode();
}
/* connect error handling and operations. */
static int ncat_connect_mode(void) {
/*
* allow/deny commands with connect make no sense. If you don't want to
* connect to a host, don't try to.
*/
if (o.allow || o.deny)
bye("Invalid option combination: allow/deny with connect.");
/* o.conn_limit with 'connect' doesn't make any sense. */
if (o.conn_limit != -1)
bye("Invalid option combination: `--max-conns' with connect.");
if (o.chat)
bye("Invalid option combination: `--chat' with connect.");
if (o.keepopen)
bye("Invalid option combination: `--keep-open' with connect.");
return ncat_connect();
}
static int ncat_listen_mode(void) {
/* Can't 'listen' AND 'connect' to a proxy server at the same time. */
if (httpconnect.storage.ss_family != AF_UNSPEC || socksconnect.storage.ss_family != AF_UNSPEC)
bye("Invalid option combination: --proxy and -l.");
if (o.idletimeout != 0)
bye("An idle timeout only works in connect mode.");
if (o.broker && o.cmdexec != NULL)
bye("Invalid option combination: --broker and -e.");
if (o.proxytype != NULL && o.telnet)
bye("Invalid option combination: --telnet has no effect with --proxy-type.");
if (o.conn_limit != -1 && !(o.keepopen || o.broker))
loguser("Warning: Maximum connections ignored, since it does not take "
"effect without -k or --broker.\n");
/* Set the default maximum simultaneous TCP connection limit. */
if (o.conn_limit == -1)
o.conn_limit = DEFAULT_MAX_CONNS;
#ifndef WIN32
/* See if the shell is executable before we get deep into this */
if (o.shellexec && access("/bin/sh", X_OK) == -1)
bye("/bin/sh is not executable, so `-c' won't work.");
#endif
if (targetss.storage.ss_family != AF_UNSPEC) {
listenaddrs[num_listenaddrs++] = targetss;
} else {
size_t ss_len;
int rc;
/* No command-line address. Listen on IPv4 or IPv6 or both. */
/* Try to bind to IPv6 first; on AIX a bound IPv4 socket blocks an IPv6
socket on the same port, despite IPV6_V6ONLY. */
#ifdef HAVE_IPV6
if (o.af == AF_INET6 || o.af == AF_UNSPEC) {
ss_len = sizeof(listenaddrs[num_listenaddrs]);
rc = resolve("::", o.portno, &listenaddrs[num_listenaddrs].storage, &ss_len, AF_INET6);
if (!rc)
bye("Failed to resolve default IPv6 address.");
num_listenaddrs++;
}
#endif
if (o.af == AF_INET || o.af == AF_UNSPEC) {
ss_len = sizeof(listenaddrs[num_listenaddrs]);
rc = resolve("0.0.0.0", o.portno, &listenaddrs[num_listenaddrs].storage, &ss_len, AF_INET);
if (!rc)
bye("Failed to resolve default IPv4 address.");
num_listenaddrs++;
}
}
if (o.proxytype) {
if (strcmp(o.proxytype, "http") == 0)
o.httpserver = 1;
}
/* Fire the listen/select dispatcher for bog-standard listen operations. */
return ncat_listen();
}
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