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iptables.c
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iptables.c
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/* Code to take an iptables-style command line and do it. */
/*
* Author: Paul.Russell@rustcorp.com.au and mneuling@radlogic.com.au
*
* (C) 2000-2002 by the netfilter coreteam <coreteam@netfilter.org>:
* Paul 'Rusty' Russell <rusty@rustcorp.com.au>
* Marc Boucher <marc+nf@mbsi.ca>
* James Morris <jmorris@intercode.com.au>
* Harald Welte <laforge@gnumonks.org>
* Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <getopt.h>
#include <string.h>
#include <netdb.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <ctype.h>
#include <stdarg.h>
#include <limits.h>
#include <unistd.h>
#include <iptables.h>
#include <fcntl.h>
#include <sys/wait.h>
#include <sys/utsname.h>
#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif
#ifndef PROC_SYS_MODPROBE
#define PROC_SYS_MODPROBE "/proc/sys/kernel/modprobe"
#endif
#define FMT_NUMERIC 0x0001
#define FMT_NOCOUNTS 0x0002
#define FMT_KILOMEGAGIGA 0x0004
#define FMT_OPTIONS 0x0008
#define FMT_NOTABLE 0x0010
#define FMT_NOTARGET 0x0020
#define FMT_VIA 0x0040
#define FMT_NONEWLINE 0x0080
#define FMT_LINENUMBERS 0x0100
#define FMT_PRINT_RULE (FMT_NOCOUNTS | FMT_OPTIONS | FMT_VIA \
| FMT_NUMERIC | FMT_NOTABLE)
#define FMT(tab,notab) ((format) & FMT_NOTABLE ? (notab) : (tab))
#define CMD_NONE 0x0000U
#define CMD_INSERT 0x0001U
#define CMD_DELETE 0x0002U
#define CMD_DELETE_NUM 0x0004U
#define CMD_REPLACE 0x0008U
#define CMD_APPEND 0x0010U
#define CMD_LIST 0x0020U
#define CMD_FLUSH 0x0040U
#define CMD_ZERO 0x0080U
#define CMD_NEW_CHAIN 0x0100U
#define CMD_DELETE_CHAIN 0x0200U
#define CMD_SET_POLICY 0x0400U
#define CMD_RENAME_CHAIN 0x0800U
#define NUMBER_OF_CMD 13
static const char cmdflags[] = { 'I', 'D', 'D', 'R', 'A', 'L', 'F', 'Z',
'N', 'X', 'P', 'E' };
#define OPTION_OFFSET 256
#define OPT_NONE 0x00000U
#define OPT_NUMERIC 0x00001U
#define OPT_SOURCE 0x00002U
#define OPT_DESTINATION 0x00004U
#define OPT_PROTOCOL 0x00008U
#define OPT_JUMP 0x00010U
#define OPT_VERBOSE 0x00020U
#define OPT_EXPANDED 0x00040U
#define OPT_VIANAMEIN 0x00080U
#define OPT_VIANAMEOUT 0x00100U
#define OPT_FRAGMENT 0x00200U
#define OPT_LINENUMBERS 0x00400U
#define OPT_COUNTERS 0x00800U
#define NUMBER_OF_OPT 12
static const char optflags[NUMBER_OF_OPT]
= { 'n', 's', 'd', 'p', 'j', 'v', 'x', 'i', 'o', 'f', '0', 'c'};
static struct option original_opts[] = {
{ "append", 1, 0, 'A' },
{ "delete", 1, 0, 'D' },
{ "insert", 1, 0, 'I' },
{ "replace", 1, 0, 'R' },
{ "list", 2, 0, 'L' },
{ "flush", 2, 0, 'F' },
{ "zero", 2, 0, 'Z' },
{ "new-chain", 1, 0, 'N' },
{ "delete-chain", 2, 0, 'X' },
{ "rename-chain", 1, 0, 'E' },
{ "policy", 1, 0, 'P' },
{ "source", 1, 0, 's' },
{ "destination", 1, 0, 'd' },
{ "src", 1, 0, 's' }, /* synonym */
{ "dst", 1, 0, 'd' }, /* synonym */
{ "protocol", 1, 0, 'p' },
{ "in-interface", 1, 0, 'i' },
{ "jump", 1, 0, 'j' },
{ "table", 1, 0, 't' },
{ "match", 1, 0, 'm' },
{ "numeric", 0, 0, 'n' },
{ "out-interface", 1, 0, 'o' },
{ "verbose", 0, 0, 'v' },
{ "exact", 0, 0, 'x' },
{ "fragments", 0, 0, 'f' },
{ "version", 0, 0, 'V' },
{ "help", 2, 0, 'h' },
{ "line-numbers", 0, 0, '0' },
{ "modprobe", 1, 0, 'M' },
{ "set-counters", 1, 0, 'c' },
{ "goto", 1, 0, 'g' },
{ 0 }
};
/* we need this for iptables-restore. iptables-restore.c sets line to the
* current line of the input file, in order to give a more precise error
* message. iptables itself doesn't need this, so it is initialized to the
* magic number of -1 */
int line = -1;
static struct option *opts = original_opts;
static unsigned int global_option_offset = 0;
/* Table of legal combinations of commands and options. If any of the
* given commands make an option legal, that option is legal (applies to
* CMD_LIST and CMD_ZERO only).
* Key:
* + compulsory
* x illegal
* optional
*/
static char commands_v_options[NUMBER_OF_CMD][NUMBER_OF_OPT] =
/* Well, it's better than "Re: Linux vs FreeBSD" */
{
/* -n -s -d -p -j -v -x -i -o -f --line -c */
/*INSERT*/ {'x',' ',' ',' ',' ',' ','x',' ',' ',' ','x',' '},
/*DELETE*/ {'x',' ',' ',' ',' ',' ','x',' ',' ',' ','x','x'},
/*DELETE_NUM*/{'x','x','x','x','x',' ','x','x','x','x','x','x'},
/*REPLACE*/ {'x',' ',' ',' ',' ',' ','x',' ',' ',' ','x',' '},
/*APPEND*/ {'x',' ',' ',' ',' ',' ','x',' ',' ',' ','x',' '},
/*LIST*/ {' ','x','x','x','x',' ',' ','x','x','x',' ','x'},
/*FLUSH*/ {'x','x','x','x','x',' ','x','x','x','x','x','x'},
/*ZERO*/ {'x','x','x','x','x',' ','x','x','x','x','x','x'},
/*NEW_CHAIN*/ {'x','x','x','x','x',' ','x','x','x','x','x','x'},
/*DEL_CHAIN*/ {'x','x','x','x','x',' ','x','x','x','x','x','x'},
/*SET_POLICY*/{'x','x','x','x','x',' ','x','x','x','x','x','x'},
/*RENAME*/ {'x','x','x','x','x',' ','x','x','x','x','x','x'}
};
static int inverse_for_options[NUMBER_OF_OPT] =
{
/* -n */ 0,
/* -s */ IPT_INV_SRCIP,
/* -d */ IPT_INV_DSTIP,
/* -p */ IPT_INV_PROTO,
/* -j */ 0,
/* -v */ 0,
/* -x */ 0,
/* -i */ IPT_INV_VIA_IN,
/* -o */ IPT_INV_VIA_OUT,
/* -f */ IPT_INV_FRAG,
/*--line*/ 0,
/* -c */ 0,
};
const char *program_version;
const char *program_name;
char *lib_dir;
int kernel_version;
/* the path to command to load kernel module */
const char *modprobe = NULL;
/* Keeping track of external matches and targets: linked lists. */
struct iptables_match *iptables_matches = NULL;
struct iptables_target *iptables_targets = NULL;
/* Extra debugging from libiptc */
extern void dump_entries(const iptc_handle_t handle);
/* A few hardcoded protocols for 'all' and in case the user has no
/etc/protocols */
struct pprot {
char *name;
u_int8_t num;
};
/* Primitive headers... */
/* defined in netinet/in.h */
#if 0
#ifndef IPPROTO_ESP
#define IPPROTO_ESP 50
#endif
#ifndef IPPROTO_AH
#define IPPROTO_AH 51
#endif
#endif
static const struct pprot chain_protos[] = {
{ "tcp", IPPROTO_TCP },
{ "udp", IPPROTO_UDP },
{ "udplite", IPPROTO_UDPLITE },
{ "icmp", IPPROTO_ICMP },
{ "esp", IPPROTO_ESP },
{ "ah", IPPROTO_AH },
{ "sctp", IPPROTO_SCTP },
{ "all", 0 },
};
static char *
proto_to_name(u_int8_t proto, int nolookup)
{
unsigned int i;
if (proto && !nolookup) {
struct protoent *pent = getprotobynumber(proto);
if (pent)
return pent->p_name;
}
for (i = 0; i < sizeof(chain_protos)/sizeof(struct pprot); i++)
if (chain_protos[i].num == proto)
return chain_protos[i].name;
return NULL;
}
int
service_to_port(const char *name, const char *proto)
{
struct servent *service;
if ((service = getservbyname(name, proto)) != NULL)
return ntohs((unsigned short) service->s_port);
return -1;
}
u_int16_t
parse_port(const char *port, const char *proto)
{
unsigned int portnum;
if ((string_to_number(port, 0, 65535, &portnum)) != -1 ||
(portnum = service_to_port(port, proto)) != -1)
return (u_int16_t)portnum;
exit_error(PARAMETER_PROBLEM,
"invalid port/service `%s' specified", port);
}
enum {
IPT_DOTTED_ADDR = 0,
IPT_DOTTED_MASK
};
static struct in_addr *
__dotted_to_addr(const char *dotted, int type)
{
static struct in_addr addr;
unsigned char *addrp;
char *p, *q;
unsigned int onebyte;
int i;
char buf[20];
/* copy dotted string, because we need to modify it */
strncpy(buf, dotted, sizeof(buf) - 1);
buf[sizeof(buf) - 1] = '\0';
addrp = (unsigned char *) &(addr.s_addr);
p = buf;
for (i = 0; i < 3; i++) {
if ((q = strchr(p, '.')) == NULL) {
if (type == IPT_DOTTED_ADDR) {
/* autocomplete, this is a network address */
if (string_to_number(p, 0, 255, &onebyte) == -1)
return (struct in_addr *) NULL;
addrp[i] = (unsigned char) onebyte;
while (i < 3)
addrp[++i] = 0;
return &addr;
} else
return (struct in_addr *) NULL;
}
*q = '\0';
if (string_to_number(p, 0, 255, &onebyte) == -1)
return (struct in_addr *) NULL;
addrp[i] = (unsigned char) onebyte;
p = q + 1;
}
/* we've checked 3 bytes, now we check the last one */
if (string_to_number(p, 0, 255, &onebyte) == -1)
return (struct in_addr *) NULL;
addrp[3] = (unsigned char) onebyte;
return &addr;
}
struct in_addr *
dotted_to_addr(const char *dotted)
{
return __dotted_to_addr(dotted, IPT_DOTTED_ADDR);
}
struct in_addr *
dotted_to_mask(const char *dotted)
{
return __dotted_to_addr(dotted, IPT_DOTTED_MASK);
}
static struct in_addr *
network_to_addr(const char *name)
{
struct netent *net;
static struct in_addr addr;
if ((net = getnetbyname(name)) != NULL) {
if (net->n_addrtype != AF_INET)
return (struct in_addr *) NULL;
addr.s_addr = htonl((unsigned long) net->n_net);
return &addr;
}
return (struct in_addr *) NULL;
}
static void
inaddrcpy(struct in_addr *dst, struct in_addr *src)
{
/* memcpy(dst, src, sizeof(struct in_addr)); */
dst->s_addr = src->s_addr;
}
static void free_opts(int reset_offset)
{
if (opts != original_opts) {
free(opts);
opts = original_opts;
if (reset_offset)
global_option_offset = 0;
}
}
void
exit_error(enum exittype status, char *msg, ...)
{
va_list args;
va_start(args, msg);
fprintf(stderr, "%s v%s: ", program_name, program_version);
vfprintf(stderr, msg, args);
va_end(args);
fprintf(stderr, "\n");
if (status == PARAMETER_PROBLEM)
exit_tryhelp(status);
if (status == VERSION_PROBLEM)
fprintf(stderr,
"Perhaps iptables or your kernel needs to be upgraded.\n");
/* On error paths, make sure that we don't leak memory */
free_opts(1);
exit(status);
}
void
exit_tryhelp(int status)
{
if (line != -1)
fprintf(stderr, "Error occurred at line: %d\n", line);
fprintf(stderr, "Try `%s -h' or '%s --help' for more information.\n",
program_name, program_name );
free_opts(1);
exit(status);
}
void
exit_printhelp(struct iptables_rule_match *matches)
{
struct iptables_rule_match *matchp = NULL;
struct iptables_target *t = NULL;
printf("%s v%s\n\n"
"Usage: %s -[AD] chain rule-specification [options]\n"
" %s -[RI] chain rulenum rule-specification [options]\n"
" %s -D chain rulenum [options]\n"
" %s -[LFZ] [chain] [options]\n"
" %s -[NX] chain\n"
" %s -E old-chain-name new-chain-name\n"
" %s -P chain target [options]\n"
" %s -h (print this help information)\n\n",
program_name, program_version, program_name, program_name,
program_name, program_name, program_name, program_name,
program_name, program_name);
printf(
"Commands:\n"
"Either long or short options are allowed.\n"
" --append -A chain Append to chain\n"
" --delete -D chain Delete matching rule from chain\n"
" --delete -D chain rulenum\n"
" Delete rule rulenum (1 = first) from chain\n"
" --insert -I chain [rulenum]\n"
" Insert in chain as rulenum (default 1=first)\n"
" --replace -R chain rulenum\n"
" Replace rule rulenum (1 = first) in chain\n"
" --list -L [chain] List the rules in a chain or all chains\n"
" --flush -F [chain] Delete all rules in chain or all chains\n"
" --zero -Z [chain] Zero counters in chain or all chains\n"
" --new -N chain Create a new user-defined chain\n"
" --delete-chain\n"
" -X [chain] Delete a user-defined chain\n"
" --policy -P chain target\n"
" Change policy on chain to target\n"
" --rename-chain\n"
" -E old-chain new-chain\n"
" Change chain name, (moving any references)\n"
"Options:\n"
" --proto -p [!] proto protocol: by number or name, eg. `tcp'\n"
" --source -s [!] address[/mask]\n"
" source specification\n"
" --destination -d [!] address[/mask]\n"
" destination specification\n"
" --in-interface -i [!] input name[+]\n"
" network interface name ([+] for wildcard)\n"
" --jump -j target\n"
" target for rule (may load target extension)\n"
#ifdef IPT_F_GOTO
" --goto -g chain\n"
" jump to chain with no return\n"
#endif
" --match -m match\n"
" extended match (may load extension)\n"
" --numeric -n numeric output of addresses and ports\n"
" --out-interface -o [!] output name[+]\n"
" network interface name ([+] for wildcard)\n"
" --table -t table table to manipulate (default: `filter')\n"
" --verbose -v verbose mode\n"
" --line-numbers print line numbers when listing\n"
" --exact -x expand numbers (display exact values)\n"
"[!] --fragment -f match second or further fragments only\n"
" --modprobe=<command> try to insert modules using this command\n"
" --set-counters PKTS BYTES set the counter during insert/append\n"
"[!] --version -V print package version.\n");
/* Print out any special helps. A user might like to be able
to add a --help to the commandline, and see expected
results. So we call help for all specified matches & targets */
for (t = iptables_targets; t ;t = t->next) {
if (t->used) {
printf("\n");
t->help();
}
}
for (matchp = matches; matchp; matchp = matchp->next) {
printf("\n");
matchp->match->help();
}
exit(0);
}
static void
generic_opt_check(int command, int options)
{
int i, j, legal = 0;
/* Check that commands are valid with options. Complicated by the
* fact that if an option is legal with *any* command given, it is
* legal overall (ie. -z and -l).
*/
for (i = 0; i < NUMBER_OF_OPT; i++) {
legal = 0; /* -1 => illegal, 1 => legal, 0 => undecided. */
for (j = 0; j < NUMBER_OF_CMD; j++) {
if (!(command & (1<<j)))
continue;
if (!(options & (1<<i))) {
if (commands_v_options[j][i] == '+')
exit_error(PARAMETER_PROBLEM,
"You need to supply the `-%c' "
"option for this command\n",
optflags[i]);
} else {
if (commands_v_options[j][i] != 'x')
legal = 1;
else if (legal == 0)
legal = -1;
}
}
if (legal == -1)
exit_error(PARAMETER_PROBLEM,
"Illegal option `-%c' with this command\n",
optflags[i]);
}
}
static char
opt2char(int option)
{
const char *ptr;
for (ptr = optflags; option > 1; option >>= 1, ptr++);
return *ptr;
}
static char
cmd2char(int option)
{
const char *ptr;
for (ptr = cmdflags; option > 1; option >>= 1, ptr++);
return *ptr;
}
static void
add_command(unsigned int *cmd, const int newcmd, const int othercmds,
int invert)
{
if (invert)
exit_error(PARAMETER_PROBLEM, "unexpected ! flag");
if (*cmd & (~othercmds))
exit_error(PARAMETER_PROBLEM, "Can't use -%c with -%c\n",
cmd2char(newcmd), cmd2char(*cmd & (~othercmds)));
*cmd |= newcmd;
}
int
check_inverse(const char option[], int *invert, int *optind, int argc)
{
if (option && strcmp(option, "!") == 0) {
if (*invert)
exit_error(PARAMETER_PROBLEM,
"Multiple `!' flags not allowed");
*invert = TRUE;
if (optind) {
*optind = *optind+1;
if (argc && *optind > argc)
exit_error(PARAMETER_PROBLEM,
"no argument following `!'");
}
return TRUE;
}
return FALSE;
}
static void *
fw_calloc(size_t count, size_t size)
{
void *p;
if ((p = calloc(count, size)) == NULL) {
perror("iptables: calloc failed");
exit(1);
}
return p;
}
static void *
fw_malloc(size_t size)
{
void *p;
if ((p = malloc(size)) == NULL) {
perror("iptables: malloc failed");
exit(1);
}
return p;
}
static struct in_addr *
host_to_addr(const char *name, unsigned int *naddr)
{
struct hostent *host;
struct in_addr *addr;
unsigned int i;
*naddr = 0;
if ((host = gethostbyname(name)) != NULL) {
if (host->h_addrtype != AF_INET ||
host->h_length != sizeof(struct in_addr))
return (struct in_addr *) NULL;
while (host->h_addr_list[*naddr] != (char *) NULL)
(*naddr)++;
addr = fw_calloc(*naddr, sizeof(struct in_addr) * *naddr);
for (i = 0; i < *naddr; i++)
inaddrcpy(&(addr[i]),
(struct in_addr *) host->h_addr_list[i]);
return addr;
}
return (struct in_addr *) NULL;
}
static char *
addr_to_host(const struct in_addr *addr)
{
struct hostent *host;
if ((host = gethostbyaddr((char *) addr,
sizeof(struct in_addr), AF_INET)) != NULL)
return (char *) host->h_name;
return (char *) NULL;
}
/*
* All functions starting with "parse" should succeed, otherwise
* the program fails.
* Most routines return pointers to static data that may change
* between calls to the same or other routines with a few exceptions:
* "host_to_addr", "parse_hostnetwork", and "parse_hostnetworkmask"
* return global static data.
*/
static struct in_addr *
parse_hostnetwork(const char *name, unsigned int *naddrs)
{
struct in_addr *addrp, *addrptmp;
if ((addrptmp = dotted_to_addr(name)) != NULL ||
(addrptmp = network_to_addr(name)) != NULL) {
addrp = fw_malloc(sizeof(struct in_addr));
inaddrcpy(addrp, addrptmp);
*naddrs = 1;
return addrp;
}
if ((addrp = host_to_addr(name, naddrs)) != NULL)
return addrp;
exit_error(PARAMETER_PROBLEM, "host/network `%s' not found", name);
}
static struct in_addr *
parse_mask(char *mask)
{
static struct in_addr maskaddr;
struct in_addr *addrp;
unsigned int bits;
if (mask == NULL) {
/* no mask at all defaults to 32 bits */
maskaddr.s_addr = 0xFFFFFFFF;
return &maskaddr;
}
if ((addrp = dotted_to_mask(mask)) != NULL)
/* dotted_to_addr already returns a network byte order addr */
return addrp;
if (string_to_number(mask, 0, 32, &bits) == -1)
exit_error(PARAMETER_PROBLEM,
"invalid mask `%s' specified", mask);
if (bits != 0) {
maskaddr.s_addr = htonl(0xFFFFFFFF << (32 - bits));
return &maskaddr;
}
maskaddr.s_addr = 0L;
return &maskaddr;
}
void
parse_hostnetworkmask(const char *name, struct in_addr **addrpp,
struct in_addr *maskp, unsigned int *naddrs)
{
struct in_addr *addrp;
char buf[256];
char *p;
int i, j, k, n;
strncpy(buf, name, sizeof(buf) - 1);
buf[sizeof(buf) - 1] = '\0';
if ((p = strrchr(buf, '/')) != NULL) {
*p = '\0';
addrp = parse_mask(p + 1);
} else
addrp = parse_mask(NULL);
inaddrcpy(maskp, addrp);
/* if a null mask is given, the name is ignored, like in "any/0" */
if (maskp->s_addr == 0L)
strcpy(buf, "0.0.0.0");
addrp = *addrpp = parse_hostnetwork(buf, naddrs);
n = *naddrs;
for (i = 0, j = 0; i < n; i++) {
addrp[j++].s_addr &= maskp->s_addr;
for (k = 0; k < j - 1; k++) {
if (addrp[k].s_addr == addrp[j - 1].s_addr) {
(*naddrs)--;
j--;
break;
}
}
}
}
struct iptables_match *
find_match(const char *name, enum ipt_tryload tryload, struct iptables_rule_match **matches)
{
struct iptables_match *ptr;
for (ptr = iptables_matches; ptr; ptr = ptr->next) {
if (strcmp(name, ptr->name) == 0) {
struct iptables_match *clone;
/* First match of this type: */
if (ptr->m == NULL)
break;
/* Second and subsequent clones */
clone = fw_malloc(sizeof(struct iptables_match));
memcpy(clone, ptr, sizeof(struct iptables_match));
clone->mflags = 0;
/* This is a clone: */
clone->next = clone;
ptr = clone;
break;
}
}
#ifndef NO_SHARED_LIBS
if (!ptr && tryload != DONT_LOAD && tryload != DURING_LOAD) {
char path[strlen(lib_dir) + sizeof("/libipt_.so")
+ strlen(name)];
#if 1 // for easier testing zzz
char s[256];
sprintf(s, "%s/libipt_%s.so", "/etc/iptext/", name);
if (dlopen(s, RTLD_NOW)) goto OPENED;
#endif
sprintf(path, "%s/libipt_%s.so", lib_dir, name);
if (dlopen(path, RTLD_NOW)) {
OPENED:
/* Found library. If it didn't register itself,
maybe they specified target as match. */
ptr = find_match(name, DONT_LOAD, NULL);
if (!ptr)
exit_error(PARAMETER_PROBLEM,
"Couldn't load match `%s'\n",
name);
} else if (tryload == LOAD_MUST_SUCCEED)
exit_error(PARAMETER_PROBLEM,
"Couldn't load match `%s':%s\n",
name, dlerror());
}
#else
if (ptr && !ptr->loaded) {
if (tryload != DONT_LOAD)
ptr->loaded = 1;
else
ptr = NULL;
}
if(!ptr && (tryload == LOAD_MUST_SUCCEED)) {
exit_error(PARAMETER_PROBLEM,
"Couldn't find match `%s'\n", name);
}
#endif
if (ptr && matches) {
struct iptables_rule_match **i;
struct iptables_rule_match *newentry;
newentry = fw_malloc(sizeof(struct iptables_rule_match));
for (i = matches; *i; i = &(*i)->next) {
if (strcmp(name, (*i)->match->name) == 0)
(*i)->completed = 1;
}
newentry->match = ptr;
newentry->completed = 0;
newentry->next = NULL;
*i = newentry;
}
return ptr;
}
/* Christophe Burki wants `-p 6' to imply `-m tcp'. */
static struct iptables_match *
find_proto(const char *pname, enum ipt_tryload tryload, int nolookup, struct iptables_rule_match **matches)
{
unsigned int proto;
if (string_to_number(pname, 0, 255, &proto) != -1) {
char *protoname = proto_to_name(proto, nolookup);
if (protoname)
return find_match(protoname, tryload, matches);
} else
return find_match(pname, tryload, matches);
return NULL;
}
u_int16_t
parse_protocol(const char *s)
{
unsigned int proto;
if (string_to_number(s, 0, 255, &proto) == -1) {
struct protoent *pent;
/* first deal with the special case of 'all' to prevent
* people from being able to redefine 'all' in nsswitch
* and/or provoke expensive [not working] ldap/nis/...
* lookups */
if (!strcmp(s, "all"))
return 0;
if ((pent = getprotobyname(s)))
proto = pent->p_proto;
else {
unsigned int i;
for (i = 0;
i < sizeof(chain_protos)/sizeof(struct pprot);
i++) {
if (strcmp(s, chain_protos[i].name) == 0) {
proto = chain_protos[i].num;
break;
}
}
if (i == sizeof(chain_protos)/sizeof(struct pprot))
exit_error(PARAMETER_PROBLEM,
"unknown protocol `%s' specified",
s);
}
}
return (u_int16_t)proto;
}
void parse_interface(const char *arg, char *vianame, unsigned char *mask)
{
int vialen = strlen(arg);
unsigned int i;
memset(mask, 0, IFNAMSIZ);
memset(vianame, 0, IFNAMSIZ);
if (vialen + 1 > IFNAMSIZ)
exit_error(PARAMETER_PROBLEM,
"interface name `%s' must be shorter than IFNAMSIZ"
" (%i)", arg, IFNAMSIZ-1);
strcpy(vianame, arg);
if ((vialen == 0) || (vialen == 1 && vianame[0] == '+'))
memset(mask, 0, IFNAMSIZ);
else if (vianame[vialen - 1] == '+') {
memset(mask, 0xFF, vialen - 1);
memset(mask + vialen - 1, 0, IFNAMSIZ - vialen + 1);
/* Don't remove `+' here! -HW */
} else {
/* Include nul-terminator in match */
memset(mask, 0xFF, vialen + 1);
memset(mask + vialen + 1, 0, IFNAMSIZ - vialen - 1);
for (i = 0; vianame[i]; i++) {
if (vianame[i] == ':' ||
vianame[i] == '!' ||
vianame[i] == '*') {
printf("Warning: weird character in interface"
" `%s' (No aliases, :, ! or *).\n",
vianame);
break;
}
}
}
}
/* Can't be zero. */
static int
parse_rulenumber(const char *rule)
{
unsigned int rulenum;
if (string_to_number(rule, 1, INT_MAX, &rulenum) == -1)
exit_error(PARAMETER_PROBLEM,
"Invalid rule number `%s'", rule);
return rulenum;
}
static const char *
parse_target(const char *targetname)
{
const char *ptr;
if (strlen(targetname) < 1)
exit_error(PARAMETER_PROBLEM,
"Invalid target name (too short)");
if (strlen(targetname)+1 > sizeof(ipt_chainlabel))
exit_error(PARAMETER_PROBLEM,
"Invalid target name `%s' (%u chars max)",
targetname, (unsigned int)sizeof(ipt_chainlabel)-1);
for (ptr = targetname; *ptr; ptr++)
if (isspace(*ptr))
exit_error(PARAMETER_PROBLEM,
"Invalid target name `%s'", targetname);
return targetname;
}
static char *
addr_to_network(const struct in_addr *addr)
{
struct netent *net;
if ((net = getnetbyaddr((long) ntohl(addr->s_addr), AF_INET)) != NULL)
return (char *) net->n_name;
return (char *) NULL;
}
char *
addr_to_dotted(const struct in_addr *addrp)
{
static char buf[20];
const unsigned char *bytep;
bytep = (const unsigned char *) &(addrp->s_addr);
sprintf(buf, "%d.%d.%d.%d", bytep[0], bytep[1], bytep[2], bytep[3]);
return buf;
}
char *
addr_to_anyname(const struct in_addr *addr)
{
char *name;
if ((name = addr_to_host(addr)) != NULL ||
(name = addr_to_network(addr)) != NULL)
return name;
return addr_to_dotted(addr);
}
char *
mask_to_dotted(const struct in_addr *mask)
{
int i;
static char buf[20];
u_int32_t maskaddr, bits;
maskaddr = ntohl(mask->s_addr);
if (maskaddr == 0xFFFFFFFFL)
/* we don't want to see "/32" */
return "";
i = 32;
bits = 0xFFFFFFFEL;
while (--i >= 0 && maskaddr != bits)
bits <<= 1;
if (i >= 0)
sprintf(buf, "/%d", i);
else
/* mask was not a decent combination of 1's and 0's */
sprintf(buf, "/%s", addr_to_dotted(mask));
return buf;
}
int