freebsd-dev/sbin/ipfw/main.c
Andrey V. Elsukov aed0267989 Rework ipfw rules parsing and printing code.
Introduce show_state structure to keep information about printed opcodes.
Split show_static_rule() function into several smaller functions. Make
parsing and printing opcodes into several passes. Each printed opcode
is marked in show_state structure and will be skipped in next passes.
Now show_static_rule() function is simple, it just prints each part
of rule separately: action, modifiers, proto, src and dst addresses,
options. The main goal of this change is avoiding occurrence of wrong
result of `ifpw show` command, that can not be parsed by ipfw(8).
Also now it is possible to make some simple static optimizations
by reordering of opcodes in the rule.

PR:		222705
Discussed with:	melifaro
MFC after:	2 weeks
Sponsored by:	Yandex LLC
2018-03-28 12:44:28 +00:00

635 lines
16 KiB
C

/*-
* 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 = TIMESTAMP_STRING;
break;
case 'T':
co.do_time = TIMESTAMP_NUMERIC;
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;
}