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freebsd-dev/sbin/ipfw/main.c
Andrey V. Elsukov d8caf56e9e Add ipfw_nat64 module that implements stateless and stateful NAT64. 
The module works together with ipfw(4) and implemented as its external
action module.

Stateless NAT64 registers external action with name nat64stl. This
keyword should be used to create NAT64 instance and to address this
instance in rules. Stateless NAT64 uses two lookup tables with mapped
IPv4->IPv6 and IPv6->IPv4 addresses to perform translation.

A configuration of instance should looks like this:
 1. Create lookup tables:
 # ipfw table T46 create type addr valtype ipv6
 # ipfw table T64 create type addr valtype ipv4
 2. Fill T46 and T64 tables.
 3. Add rule to allow neighbor solicitation and advertisement:
 # ipfw add allow icmp6 from any to any icmp6types 135,136
 4. Create NAT64 instance:
 # ipfw nat64stl NAT create table4 T46 table6 T64
 5. Add rules that matches the traffic:
 # ipfw add nat64stl NAT ip from any to table(T46)
 # ipfw add nat64stl NAT ip from table(T64) to 64:ff9b::/96
 6. Configure DNS64 for IPv6 clients and add route to 64:ff9b::/96
    via NAT64 host.

Stateful NAT64 registers external action with name nat64lsn. The only
one option required to create nat64lsn instance - prefix4. It defines
the pool of IPv4 addresses used for translation.

A configuration of instance should looks like this:
 1. Add rule to allow neighbor solicitation and advertisement:
 # ipfw add allow icmp6 from any to any icmp6types 135,136
 2. Create NAT64 instance:
 # ipfw nat64lsn NAT create prefix4 A.B.C.D/28
 3. Add rules that matches the traffic:
 # ipfw add nat64lsn NAT ip from any to A.B.C.D/28
 # ipfw add nat64lsn NAT ip6 from any to 64:ff9b::/96
 4. Configure DNS64 for IPv6 clients and add route to 64:ff9b::/96
    via NAT64 host.

Obtained from:	Yandex LLC
Relnotes:	yes
Sponsored by:	Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D6434
2016-08-13 16:09:49 +00:00

635 lines
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/*
* Copyright (c) 2002-2003,2010 Luigi Rizzo
* Copyright (c) 1996 Alex Nash, Paul Traina, Poul-Henning Kamp
* Copyright (c) 1994 Ugen J.S.Antsilevich
*
* Idea and grammar partially left from:
* Copyright (c) 1993 Daniel Boulet
*
* Redistribution and use in source forms, with and without modification,
* are permitted provided that this entire comment appears intact.
*
* Redistribution in binary form may occur without any restrictions.
* Obviously, it would be nice if you gave credit where credit is due
* but requiring it would be too onerous.
*
* This software is provided ``AS IS'' without any warranties of any kind.
*
* Command line interface for IP firewall facility
*
* $FreeBSD$
*/
#include <sys/wait.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
#include "ipfw2.h"
static void
help(void)
{
fprintf(stderr,
"ipfw syntax summary (but please do read the ipfw(8) manpage):\n\n"
"\tipfw [-abcdefhnNqStTv] <command>\n\n"
"where <command> is one of the following:\n\n"
"add [num] [set N] [prob x] RULE-BODY\n"
"{pipe|queue} N config PIPE-BODY\n"
"[pipe|queue] {zero|delete|show} [N{,N}]\n"
"nat N config {ip IPADDR|if IFNAME|log|deny_in|same_ports|unreg_only|reset|\n"
" reverse|proxy_only|redirect_addr linkspec|\n"
" redirect_port linkspec|redirect_proto linkspec}\n"
"set [disable N... enable N...] | move [rule] X to Y | swap X Y | show\n"
"set N {show|list|zero|resetlog|delete} [N{,N}] | flush\n"
"table N {add ip[/bits] [value] | delete ip[/bits] | flush | list}\n"
"table all {flush | list}\n"
"\n"
"RULE-BODY: check-state [PARAMS] | ACTION [PARAMS] ADDR [OPTION_LIST]\n"
"ACTION: check-state | allow | count | deny | unreach{,6} CODE |\n"
" skipto N | {divert|tee} PORT | forward ADDR |\n"
" pipe N | queue N | nat N | setfib FIB | reass\n"
"PARAMS: [log [logamount LOGLIMIT]] [altq QUEUE_NAME]\n"
"ADDR: [ MAC dst src ether_type ] \n"
" [ ip from IPADDR [ PORT ] to IPADDR [ PORTLIST ] ]\n"
" [ ipv6|ip6 from IP6ADDR [ PORT ] to IP6ADDR [ PORTLIST ] ]\n"
"IPADDR: [not] { any | me | ip/bits{x,y,z} | table(t[,v]) | IPLIST }\n"
"IP6ADDR: [not] { any | me | me6 | ip6/bits | IP6LIST }\n"
"IP6LIST: { ip6 | ip6/bits }[,IP6LIST]\n"
"IPLIST: { ip | ip/bits | ip:mask }[,IPLIST]\n"
"OPTION_LIST: OPTION [OPTION_LIST]\n"
"OPTION: bridged | diverted | diverted-loopback | diverted-output |\n"
" {dst-ip|src-ip} IPADDR | {dst-ip6|src-ip6|dst-ipv6|src-ipv6} IP6ADDR |\n"
" {dst-port|src-port} LIST |\n"
" estab | frag | {gid|uid} N | icmptypes LIST | in | out | ipid LIST |\n"
" iplen LIST | ipoptions SPEC | ipprecedence | ipsec | iptos SPEC |\n"
" ipttl LIST | ipversion VER | keep-state | layer2 | limit ... |\n"
" icmp6types LIST | ext6hdr LIST | flow-id N[,N] | fib FIB |\n"
" mac ... | mac-type LIST | proto LIST | {recv|xmit|via} {IF|IPADDR} |\n"
" setup | {tcpack|tcpseq|tcpwin} NN | tcpflags SPEC | tcpoptions SPEC |\n"
" tcpdatalen LIST | verrevpath | versrcreach | antispoof\n"
);
exit(0);
}
/*
* Called with the arguments, including program name because getopt
* wants it to be present.
* Returns 0 if successful, 1 if empty command, errx() in case of errors.
* First thing we do is process parameters creating an argv[] array
* which includes the program name and a NULL entry at the end.
* If we are called with a single string, we split it on whitespace.
* Also, arguments with a trailing ',' are joined to the next one.
* The pointers (av[]) and data are in a single chunk of memory.
* av[0] points to the original program name, all other entries
* point into the allocated chunk.
*/
static int
ipfw_main(int oldac, char **oldav)
{
int ch, ac;
const char *errstr;
char **av, **save_av;
int do_acct = 0; /* Show packet/byte count */
int try_next = 0; /* set if pipe cmd not found */
int av_size; /* compute the av size */
char *av_p; /* used to build the av list */
#define WHITESP " \t\f\v\n\r"
if (oldac < 2)
return 1; /* need at least one argument */
if (oldac == 2) {
/*
* If we are called with one argument, try to split it into
* words for subsequent parsing. Spaces after a ',' are
* removed by copying the string in-place.
*/
char *arg = oldav[1]; /* The string is the first arg. */
int l = strlen(arg);
int copy = 0; /* 1 if we need to copy, 0 otherwise */
int i, j;
for (i = j = 0; i < l; i++) {
if (arg[i] == '#') /* comment marker */
break;
if (copy) {
arg[j++] = arg[i];
copy = !strchr("," WHITESP, arg[i]);
} else {
copy = !strchr(WHITESP, arg[i]);
if (copy)
arg[j++] = arg[i];
}
}
if (!copy && j > 0) /* last char was a 'blank', remove it */
j--;
l = j; /* the new argument length */
arg[j++] = '\0';
if (l == 0) /* empty string! */
return 1;
/*
* First, count number of arguments. Because of the previous
* processing, this is just the number of blanks plus 1.
*/
for (i = 0, ac = 1; i < l; i++)
if (strchr(WHITESP, arg[i]) != NULL)
ac++;
/*
* Allocate the argument list structure as a single block
* of memory, containing pointers and the argument
* strings. We include one entry for the program name
* because getopt expects it, and a NULL at the end
* to simplify further parsing.
*/
ac++; /* add 1 for the program name */
av_size = (ac+1) * sizeof(char *) + l + 1;
av = safe_calloc(av_size, 1);
/*
* Init the argument pointer to the end of the array
* and copy arguments from arg[] to av[]. For each one,
* j is the initial character, i is the one past the end.
*/
av_p = (char *)&av[ac+1];
for (ac = 1, i = j = 0; i < l; i++) {
if (strchr(WHITESP, arg[i]) != NULL || i == l-1) {
if (i == l-1)
i++;
bcopy(arg+j, av_p, i-j);
av[ac] = av_p;
av_p += i-j; /* the length of the string */
*av_p++ = '\0';
ac++;
j = i + 1;
}
}
} else {
/*
* If an argument ends with ',' join with the next one.
*/
int first, i, l=0;
/*
* Allocate the argument list structure as a single block
* of memory, containing both pointers and the argument
* strings. We include some space for the program name
* because getopt expects it.
* We add an extra pointer to the end of the array,
* to make simpler further parsing.
*/
for (i=0; i<oldac; i++)
l += strlen(oldav[i]);
av_size = (oldac+1) * sizeof(char *) + l + oldac;
av = safe_calloc(av_size, 1);
/*
* Init the argument pointer to the end of the array
* and copy arguments from arg[] to av[]
*/
av_p = (char *)&av[oldac+1];
for (first = i = ac = 1, l = 0; i < oldac; i++) {
char *arg = oldav[i];
int k = strlen(arg);
l += k;
if (arg[k-1] != ',' || i == oldac-1) {
/* Time to copy. */
av[ac] = av_p;
for (l=0; first <= i; first++) {
strcat(av_p, oldav[first]);
av_p += strlen(oldav[first]);
}
*av_p++ = '\0';
ac++;
l = 0;
first = i+1;
}
}
}
/*
* set the progname pointer to the original string
* and terminate the array with null
*/
av[0] = oldav[0];
av[ac] = NULL;
/* Set the force flag for non-interactive processes */
if (!co.do_force)
co.do_force = !isatty(STDIN_FILENO);
#ifdef EMULATE_SYSCTL /* sysctl emulation */
if ( ac >= 2 && !strcmp(av[1], "sysctl")) {
char *s;
int i;
if (ac != 3) {
printf( "sysctl emulation usage:\n"
" ipfw sysctl name[=value]\n"
" ipfw sysctl -a\n");
return 0;
}
s = strchr(av[2], '=');
if (s == NULL) {
s = !strcmp(av[2], "-a") ? NULL : av[2];
sysctlbyname(s, NULL, NULL, NULL, 0);
} else { /* ipfw sysctl x.y.z=value */
/* assume an INT value, will extend later */
if (s[1] == '\0') {
printf("ipfw sysctl: missing value\n\n");
return 0;
}
*s = '\0';
i = strtol(s+1, NULL, 0);
sysctlbyname(av[2], NULL, NULL, &i, sizeof(int));
}
return 0;
}
#endif
/* Save arguments for final freeing of memory. */
save_av = av;
optind = optreset = 1; /* restart getopt() */
while ((ch = getopt(ac, av, "abcdefhinNp:qs:STtv")) != -1)
switch (ch) {
case 'a':
do_acct = 1;
break;
case 'b':
co.comment_only = 1;
co.do_compact = 1;
break;
case 'c':
co.do_compact = 1;
break;
case 'd':
co.do_dynamic = 1;
break;
case 'e':
co.do_expired = 1;
break;
case 'f':
co.do_force = 1;
break;
case 'h': /* help */
free(save_av);
help();
break; /* NOTREACHED */
case 'i':
co.do_value_as_ip = 1;
break;
case 'n':
co.test_only = 1;
break;
case 'N':
co.do_resolv = 1;
break;
case 'p':
errx(EX_USAGE, "An absolute pathname must be used "
"with -p option.");
/* NOTREACHED */
case 'q':
co.do_quiet = 1;
break;
case 's': /* sort */
co.do_sort = atoi(optarg);
break;
case 'S':
co.show_sets = 1;
break;
case 't':
co.do_time = 1;
break;
case 'T':
co.do_time = 2; /* numeric timestamp */
break;
case 'v': /* verbose */
co.verbose = 1;
break;
default:
free(save_av);
return 1;
}
ac -= optind;
av += optind;
NEED1("bad arguments, for usage summary ``ipfw''");
/*
* An undocumented behaviour of ipfw1 was to allow rule numbers first,
* e.g. "100 add allow ..." instead of "add 100 allow ...".
* In case, swap first and second argument to get the normal form.
*/
if (ac > 1 && isdigit(*av[0])) {
char *p = av[0];
av[0] = av[1];
av[1] = p;
}
/*
* Optional: pipe, queue or nat.
*/
co.do_nat = 0;
co.do_pipe = 0;
co.use_set = 0;
if (!strncmp(*av, "nat", strlen(*av)))
co.do_nat = 1;
else if (!strncmp(*av, "pipe", strlen(*av)))
co.do_pipe = 1;
else if (_substrcmp(*av, "queue") == 0)
co.do_pipe = 2;
else if (_substrcmp(*av, "flowset") == 0)
co.do_pipe = 2;
else if (_substrcmp(*av, "sched") == 0)
co.do_pipe = 3;
else if (!strncmp(*av, "set", strlen(*av))) {
if (ac > 1 && isdigit(av[1][0])) {
co.use_set = strtonum(av[1], 0, resvd_set_number,
&errstr);
if (errstr)
errx(EX_DATAERR,
"invalid set number %s\n", av[1]);
ac -= 2; av += 2; co.use_set++;
}
}
if (co.do_pipe || co.do_nat) {
ac--;
av++;
}
NEED1("missing command");
/*
* For pipes, queues and nats we normally say 'nat|pipe NN config'
* but the code is easier to parse as 'nat|pipe config NN'
* so we swap the two arguments.
*/
if ((co.do_pipe || co.do_nat) && ac > 1 && isdigit(*av[0])) {
char *p = av[0];
av[0] = av[1];
av[1] = p;
}
if (co.use_set == 0) {
if (_substrcmp(*av, "add") == 0)
ipfw_add(av);
else if (co.do_nat && _substrcmp(*av, "show") == 0)
ipfw_show_nat(ac, av);
else if (co.do_pipe && _substrcmp(*av, "config") == 0)
ipfw_config_pipe(ac, av);
else if (co.do_nat && _substrcmp(*av, "config") == 0)
ipfw_config_nat(ac, av);
else if (_substrcmp(*av, "set") == 0)
ipfw_sets_handler(av);
else if (_substrcmp(*av, "table") == 0)
ipfw_table_handler(ac, av);
else if (_substrcmp(*av, "enable") == 0)
ipfw_sysctl_handler(av, 1);
else if (_substrcmp(*av, "disable") == 0)
ipfw_sysctl_handler(av, 0);
else
try_next = 1;
}
if (co.use_set || try_next) {
if (_substrcmp(*av, "delete") == 0)
ipfw_delete(av);
else if (!strncmp(*av, "nat64stl", strlen(*av)))
ipfw_nat64stl_handler(ac, av);
else if (!strncmp(*av, "nat64lsn", strlen(*av)))
ipfw_nat64lsn_handler(ac, av);
else if (!strncmp(*av, "nptv6", strlen(*av)))
ipfw_nptv6_handler(ac, av);
else if (_substrcmp(*av, "flush") == 0)
ipfw_flush(co.do_force);
else if (_substrcmp(*av, "zero") == 0)
ipfw_zero(ac, av, 0 /* IP_FW_ZERO */);
else if (_substrcmp(*av, "resetlog") == 0)
ipfw_zero(ac, av, 1 /* IP_FW_RESETLOG */);
else if (_substrcmp(*av, "print") == 0 ||
_substrcmp(*av, "list") == 0)
ipfw_list(ac, av, do_acct);
else if (_substrcmp(*av, "show") == 0)
ipfw_list(ac, av, 1 /* show counters */);
else if (_substrcmp(*av, "table") == 0)
ipfw_table_handler(ac, av);
else if (_substrcmp(*av, "internal") == 0)
ipfw_internal_handler(ac, av);
else
errx(EX_USAGE, "bad command `%s'", *av);
}
/* Free memory allocated in the argument parsing. */
free(save_av);
return 0;
}
static void
ipfw_readfile(int ac, char *av[])
{
#define MAX_ARGS 32
char buf[4096];
char *progname = av[0]; /* original program name */
const char *cmd = NULL; /* preprocessor name, if any */
const char *filename = av[ac-1]; /* file to read */
int c, lineno=0;
FILE *f = NULL;
pid_t preproc = 0;
while ((c = getopt(ac, av, "cfNnp:qS")) != -1) {
switch(c) {
case 'c':
co.do_compact = 1;
break;
case 'f':
co.do_force = 1;
break;
case 'N':
co.do_resolv = 1;
break;
case 'n':
co.test_only = 1;
break;
case 'p':
/*
* ipfw -p cmd [args] filename
*
* We are done with getopt(). All arguments
* except the filename go to the preprocessor,
* so we need to do the following:
* - check that a filename is actually present;
* - advance av by optind-1 to skip arguments
* already processed;
* - decrease ac by optind, to remove the args
* already processed and the final filename;
* - set the last entry in av[] to NULL so
* popen() can detect the end of the array;
* - set optind=ac to let getopt() terminate.
*/
if (optind == ac)
errx(EX_USAGE, "no filename argument");
cmd = optarg;
av[ac-1] = NULL;
av += optind - 1;
ac -= optind;
optind = ac;
break;
case 'q':
co.do_quiet = 1;
break;
case 'S':
co.show_sets = 1;
break;
default:
errx(EX_USAGE, "bad arguments, for usage"
" summary ``ipfw''");
}
}
if (cmd == NULL && ac != optind + 1)
errx(EX_USAGE, "extraneous filename arguments %s", av[ac-1]);
if ((f = fopen(filename, "r")) == NULL)
err(EX_UNAVAILABLE, "fopen: %s", filename);
if (cmd != NULL) { /* pipe through preprocessor */
int pipedes[2];
if (pipe(pipedes) == -1)
err(EX_OSERR, "cannot create pipe");
preproc = fork();
if (preproc == -1)
err(EX_OSERR, "cannot fork");
if (preproc == 0) {
/*
* Child, will run the preprocessor with the
* file on stdin and the pipe on stdout.
*/
if (dup2(fileno(f), 0) == -1
|| dup2(pipedes[1], 1) == -1)
err(EX_OSERR, "dup2()");
fclose(f);
close(pipedes[1]);
close(pipedes[0]);
execvp(cmd, av);
err(EX_OSERR, "execvp(%s) failed", cmd);
} else { /* parent, will reopen f as the pipe */
fclose(f);
close(pipedes[1]);
if ((f = fdopen(pipedes[0], "r")) == NULL) {
int savederrno = errno;
(void)kill(preproc, SIGTERM);
errno = savederrno;
err(EX_OSERR, "fdopen()");
}
}
}
while (fgets(buf, sizeof(buf), f)) { /* read commands */
char linename[20];
char *args[2];
lineno++;
snprintf(linename, sizeof(linename), "Line %d", lineno);
setprogname(linename); /* XXX */
args[0] = progname;
args[1] = buf;
ipfw_main(2, args);
}
fclose(f);
if (cmd != NULL) {
int status;
if (waitpid(preproc, &status, 0) == -1)
errx(EX_OSERR, "waitpid()");
if (WIFEXITED(status) && WEXITSTATUS(status) != EX_OK)
errx(EX_UNAVAILABLE,
"preprocessor exited with status %d",
WEXITSTATUS(status));
else if (WIFSIGNALED(status))
errx(EX_UNAVAILABLE,
"preprocessor exited with signal %d",
WTERMSIG(status));
}
}
int
main(int ac, char *av[])
{
#if defined(_WIN32) && defined(TCC)
{
WSADATA wsaData;
int ret=0;
unsigned short wVersionRequested = MAKEWORD(2, 2);
ret = WSAStartup(wVersionRequested, &wsaData);
if (ret != 0) {
/* Tell the user that we could not find a usable */
/* Winsock DLL. */
printf("WSAStartup failed with error: %d\n", ret);
return 1;
}
}
#endif
/*
* If the last argument is an absolute pathname, interpret it
* as a file to be preprocessed.
*/
if (ac > 1 && av[ac - 1][0] == '/') {
if (access(av[ac - 1], R_OK) == 0)
ipfw_readfile(ac, av);
else
err(EX_USAGE, "pathname: %s", av[ac - 1]);
} else {
if (ipfw_main(ac, av)) {
errx(EX_USAGE,
"usage: ipfw [options]\n"
"do \"ipfw -h\" or \"man ipfw\" for details");
}
}
return EX_OK;
}
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