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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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/***************************************************************************
* util.c -- Various utility 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 "sys_wrap.h"
#include "util.h"
#include "ncat.h"
#include "nbase.h"
#include "sockaddr_u.h"
#include <assert.h>
#include <stdio.h>
#ifdef WIN32
#include <iphlpapi.h>
#endif
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
/* safely add 2 size_t */
size_t sadd(size_t l, size_t r)
{
size_t t;
t = l + r;
if (t < l)
bye("integer overflow %lu + %lu.", (u_long)l, (u_long)r);
return t;
}
/* safely multiply 2 size_t */
size_t smul(size_t l, size_t r)
{
size_t t;
t = l * r;
if (l && t / l != r)
bye("integer overflow %lu * %lu.", (u_long)l, (u_long)r);
return t;
}
#ifdef WIN32
void windows_init()
{
WORD werd;
WSADATA data;
werd = MAKEWORD( 2, 2 );
if ( (WSAStartup(werd, &data)) !=0 )
bye("Failed to start WinSock.");
}
#endif
/* Use this to print debug or diagnostic messages to avoid polluting the user
stream. */
void loguser(const char *fmt, ...)
{
va_list ap;
fprintf(stderr, "%s: ", NCAT_NAME);
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
}
/* Log a user message without the "Ncat: " prefix, to allow building up a line
with a series of strings. */
void loguser_noprefix(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
}
void logdebug(const char *fmt, ...)
{
va_list ap;
fprintf(stderr, "NCAT DEBUG: ");
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
}
/* Exit status 2 indicates a program error other than a network error. */
void die(char *err)
{
perror(err);
exit(2);
}
/* adds newline for you */
void bye(const char *fmt, ...)
{
va_list ap;
fprintf(stderr, "%s: ", NCAT_NAME);
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, " QUITTING.\n");
exit(2);
}
/* zero out some mem, bzero() is deprecated */
void zmem(void *mem, size_t n)
{
memset(mem, 0, n);
}
/* Append n bytes starting at s to a malloc-allocated buffer. Reallocates the
buffer and updates the variables to make room if necessary. */
int strbuf_append(char **buf, size_t *size, size_t *offset, const char *s, size_t n)
{
assert(*offset <= *size);
if (n >= *size - *offset) {
*size += n + 1;
*buf = (char*) safe_realloc(*buf, *size);
}
memcpy(*buf + *offset, s, n);
*offset += n;
(*buf)[*offset] = '\0';
return n;
}
/* Append a '\0'-terminated string as with strbuf_append. */
int strbuf_append_str(char **buf, size_t *size, size_t *offset, const char *s)
{
return strbuf_append(buf, size, offset, s, strlen(s));
}
/* Do a sprintf at the given offset into a malloc-allocated buffer. Reallocates
the buffer and updates the variables to make room if necessary. */
int strbuf_sprintf(char **buf, size_t *size, size_t *offset, const char *fmt, ...)
{
va_list va;
int n;
assert(*offset <= *size);
if (*buf == NULL) {
*size = 1;
*buf = (char*) safe_malloc(*size);
}
for (;;) {
va_start(va, fmt);
n = Vsnprintf(*buf + *offset, *size - *offset, fmt, va);
va_end(va);
if (n < 0)
*size = MAX(*size, 1) * 2;
else if (n >= *size - *offset)
*size += n + 1;
else
break;
*buf = (char*) safe_realloc(*buf, *size);
}
*offset += n;
return n;
}
/* Make a new allocated null-terminated string from the bytes [start, end). */
char *mkstr(const char *start, const char *end)
{
char *s;
assert(end >= start);
s = (char *) safe_malloc(end - start + 1);
memcpy(s, start, end - start);
s[end - start] = '\0';
return s;
}
/* Return true if the given address is a local one. */
int addr_is_local(const union sockaddr_u *su)
{
struct addrinfo hints = { 0 }, *addrs, *addr;
char hostname[128];
/* Check loopback addresses. */
if (su->storage.ss_family == AF_INET) {
if ((ntohl(su->in.sin_addr.s_addr) & 0xFF000000UL) == 0x7F000000UL)
return 1;
if (ntohl(su->in.sin_addr.s_addr) == 0x00000000UL)
return 1;
}
#ifdef HAVE_IPV6
else if (su->storage.ss_family == AF_INET6) {
if (memcmp(&su->in6.sin6_addr, &in6addr_any, sizeof(su->in6.sin6_addr)) == 0
|| memcmp(&su->in6.sin6_addr, &in6addr_loopback, sizeof(su->in6.sin6_addr)) == 0)
return 1;
}
#endif
/* Check addresses assigned to the local host name. */
if (gethostname(hostname, sizeof(hostname)) == -1)
return 0;
hints.ai_family = su->storage.ss_family;
if (getaddrinfo(hostname, NULL, &hints, &addrs) != 0)
return 0;
for (addr = addrs; addr != NULL; addr = addr->ai_next) {
union sockaddr_u addr_su;
if (addr->ai_family != su->storage.ss_family)
continue;
if (addr->ai_addrlen > sizeof(addr_su)) {
bye("getaddrinfo returned oversized address (%u > %u)",
addr->ai_addrlen, sizeof(addr_su));
}
memcpy(&addr_su, addr->ai_addr, addr->ai_addrlen);
if (su->storage.ss_family == AF_INET) {
if (su->in.sin_addr.s_addr == addr_su.in.sin_addr.s_addr)
break;
} else if (su->storage.ss_family == AF_INET6) {
if (memcmp(&su->in6.sin6_addr, &addr_su.in6.sin6_addr, sizeof(su->in6.sin6_addr)) == 0)
break;
}
}
if (addr != NULL) {
freeaddrinfo(addrs);
return 1;
} else {
return 0;
}
}
/* Converts an IP address given in a sockaddr_u to an IPv4 or
IPv6 IP address string. Since a static buffer is returned, this is
not thread-safe and can only be used once in calls like printf()
*/
const char *inet_socktop(const union sockaddr_u *su) {
static char buf[INET6_ADDRSTRLEN + 1];
void *addr;
if (su->storage.ss_family == AF_INET)
addr = (void *) &su->in.sin_addr;
#if HAVE_IPV6
else if (su->storage.ss_family == AF_INET6)
addr = (void *) &su->in6.sin6_addr;
#endif
else
addr = NULL;
if (inet_ntop(su->storage.ss_family, addr, buf, sizeof(buf)) == NULL) {
bye("Failed to convert address to presentation format! Error: %s.",
strerror(socket_errno()));
}
return buf;
}
/* Returns the port number in HOST BYTE ORDER based on the su's family */
unsigned short inet_port(const union sockaddr_u *su)
{
if (su->storage.ss_family == AF_INET)
return ntohs(su->in.sin_port);
#if HAVE_IPV6
else if (su->storage.ss_family == AF_INET6)
return ntohs(su->in6.sin6_port);
#endif
bye("Invalid address family passed to inet_port().");
return 0;
}
int do_listen(int type, int proto, const union sockaddr_u *srcaddr_u)
{
int sock = 0, option_on = 1;
size_t sa_len;
if (type != SOCK_STREAM && type != SOCK_DGRAM)
return -1;
/* We need a socket that can be inherited by child processes in
ncat_exec_win.c, for --exec and --sh-exec. inheritable_socket is from
nbase. */
sock = inheritable_socket(srcaddr_u->storage.ss_family, type, proto);
Setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &option_on, sizeof(int));
/* IPPROTO_IPV6 is defined in Visual C++ only when _WIN32_WINNT >= 0x501.
Nbase's nbase_winunix.h defines _WIN32_WINNT to a lower value for
compatibility with older versions of Windows. This code disables IPv6 sockets
that also receive IPv4 connections. This is the default on Windows anyway so
it doesn't make a difference.
http://support.microsoft.com/kb/950688
http://msdn.microsoft.com/en-us/library/bb513665
*/
#ifdef IPPROTO_IPV6
if (srcaddr_u->storage.ss_family == AF_INET6) {
int set = 1;
/* Tell it to not try and bind to IPV4 */
if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &set, sizeof(set))== -1)
die("Unable to set IPV6 socket to bind only to IPV6");
}
#endif
#ifdef HAVE_SOCKADDR_SA_LEN
sa_len = srcaddr_u->sockaddr.sa_len;
#else
sa_len = sizeof(*srcaddr_u);
#endif
if (bind(sock, &srcaddr_u->sockaddr, sa_len) < 0) {
bye("bind to %s:%hu: %s.", inet_socktop(srcaddr_u),
inet_port(srcaddr_u), socket_strerror(socket_errno()));
}
if (type == SOCK_STREAM)
Listen(sock, BACKLOG);
if (o.verbose)
loguser("Listening on %s:%hu\n", inet_socktop(srcaddr_u), inet_port(srcaddr_u));
return sock;
}
int do_connect(int type)
{
int sock = 0;
if (type != SOCK_STREAM && type != SOCK_DGRAM)
return -1;
/* We need a socket that can be inherited by child processes in
ncat_exec_win.c, for --exec and --sh-exec. inheritable_socket is from
nbase. */
sock = inheritable_socket(targetss.storage.ss_family, type, 0);
if (srcaddr.storage.ss_family != AF_UNSPEC) {
size_t sa_len;
#ifdef HAVE_SOCKADDR_SA_LEN
sa_len = srcaddr.sockaddr.sa_len;
#else
sa_len = sizeof(srcaddr);
#endif
if (bind(sock, &srcaddr.sockaddr, sa_len) < 0) {
bye("bind to %s:%hu: %s.", inet_socktop(&srcaddr),
inet_port(&srcaddr), socket_strerror(socket_errno()));
}
}
if (sock != -1) {
if (connect(sock, &targetss.sockaddr, (int) targetsslen)!= -1)
return sock;
else if (socket_errno()==EINPROGRESS||socket_errno()==EAGAIN)
return sock;
}
return -1 ;
}
unsigned char *buildsrcrte(struct in_addr dstaddr, struct in_addr routes[],
int numroutes, int ptr, size_t *len)
{
int x;
unsigned char *opts, *p;
*len = (numroutes + 1) * sizeof(struct in_addr) + 4;
if (numroutes > 8)
bye("Bad number of routes passed to buildsrcrte().");
opts = (unsigned char *) safe_malloc(*len);
p = opts;
zmem(opts, *len);
*p++ = 0x01; /* IPOPT_NOP, for alignment */
*p++ = 0x83; /* IPOPT_LSRR */
*p++ = (char) (*len - 1); /* subtract nop */
*p++ = (char) ptr;
for (x = 0; x < numroutes; x++) {
memcpy(p, &routes[x], sizeof(routes[x]));
p += sizeof(routes[x]);
}
memcpy(p, &dstaddr, sizeof(dstaddr));
return opts;
}
int allow_access(const union sockaddr_u *su)
{
/* A host not in the allow set is denied, but only if the --allow or
--allowfile option was given. */
if (o.allow && !addrset_contains(&o.allowset, &su->sockaddr))
return 0;
if (addrset_contains(&o.denyset, &su->sockaddr))
return 0;
return 1;
}
/*
* ugly code to maintain our list of fds so we can have proper fdmax for
* select(). really this should be generic list code, not this silly bit of
* stupidity. -sean
*/
/* add an fdinfo to our list */
int add_fdinfo(fd_list_t *fdl, struct fdinfo *s)
{
if (fdl->nfds >= fdl->maxfds)
return -1;
fdl->fds[fdl->nfds] = *s;
fdl->nfds++;
if (s->fd > fdl->fdmax)
fdl->fdmax = s->fd;
if (o.debug > 1)
logdebug("Added fd %d to list, nfds %d, maxfd %d\n", s->fd, fdl->nfds, fdl->fdmax);
return 0;
}
/* Add a descriptor to the list. Use this when you are only adding to the list
* for the side effect of increasing fdmax, and don't care about fdinfo
* members. */
int add_fd(fd_list_t *fdl, int fd)
{
struct fdinfo info = { 0 };
info.fd = fd;
return add_fdinfo(fdl, &info);
}
/* remove a descriptor from our list */
int rm_fd(fd_list_t *fdl, int fd)
{
int x = 0, last = fdl->nfds;
/* make sure we have a list */
if (last == 0)
bye("Program bug: Trying to remove fd from list with no fds.");
/* find the fd in the list */
for (x = 0; x < last; x++)
if (fdl->fds[x].fd == fd)
break;
/* make sure we found it */
if (x == last)
bye("Program bug: fd (%d) not on list.", fd);
/* remove it, does nothing if (last == 1) */
if (o.debug > 1)
logdebug("Swapping fd[%d] (%d) with fd[%d] (%d)\n",
x, fdl->fds[x].fd, last - 1, fdl->fds[last - 1].fd);
fdl->fds[x] = fdl->fds[last - 1];
fdl->nfds--;
/* was it the max */
if (fd == fdl->fdmax)
fdl->fdmax = get_maxfd(fdl);
if (o.debug > 1)
logdebug("Removed fd %d from list, nfds %d, maxfd %d\n", fd, fdl->nfds, fdl->fdmax);
return 0;
}
/* find the max descriptor in our list */
int get_maxfd(fd_list_t *fdl)
{
int x = 0, max = -1, nfds = fdl->nfds;
for (x = 0; x < nfds; x++)
if (fdl->fds[x].fd > max)
max = fdl->fds[x].fd;
return max;
}
struct fdinfo *get_fdinfo(const fd_list_t *fdl, int fd)
{
int x;
for (x = 0; x < fdl->nfds; x++)
if (fdl->fds[x].fd == fd)
return &fdl->fds[x];
return NULL;
}
void init_fdlist(fd_list_t *fdl, int maxfds)
{
fdl->fds = (struct fdinfo *) Calloc(maxfds, sizeof(struct fdinfo));
fdl->nfds = 0;
fdl->fdmax = -1;
fdl->maxfds = maxfds;
if (o.debug > 1)
logdebug("Initialized fdlist with %d maxfds\n", maxfds);
}
void free_fdlist(fd_list_t *fdl)
{
free(fdl->fds);
fdl->nfds = 0;
fdl->fdmax = -1;
}
/* If any changes need to be made to EOL sequences to comply with --crlf
* then dst will be populated with the modified src, len will be adjusted
* accordingly and the return will be non-zero.
*
* state is used to keep track of line endings that span more than one call to
* this function. On the first call, state should be a pointer to a int
* containing 0. Thereafter, keep passing the same pointer. Separate logical
* streams should use separate state pointers.
*
* Returns 0 if changes were not made - len and dst will remain untouched.
*/
int fix_line_endings(char *src, int *len, char **dst, int *state)
{
int fix_count;
int i,j;
int num_bytes = *len;
int prev_state = *state;
/* *state is true iff the last byte of the previous block was \r. */
if (num_bytes > 0)
*state = (src[num_bytes - 1] == '\r');
/* get count of \n without matching \r */
fix_count = 0;
for (i = 0; i < num_bytes; i++) {
if (src[i] == '\n' && ((i == 0) ? !prev_state : src[i-1] != '\r'))
fix_count++;
}
if (fix_count <= 0 ) return 0;
/* now insert matching \r */
*dst = (char *) safe_malloc(num_bytes + fix_count);
j = 0;
for (i = 0; i < num_bytes; i++) {
if (src[i] == '\n' && ((i == 0) ? !prev_state : src[i-1] != '\r')) {
memcpy(*dst + j, "\r\n", 2);
j += 2;
} else {
memcpy(*dst + j, src + i, 1);
j++;
}
}
*len += fix_count;
return 1;
}
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