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miniupnp/miniupnpd/netfilter/iptcrdr.c

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/* $Id: iptcrdr.c,v 1.50 2012/10/03 14:49:08 nanard Exp $ */
/* MiniUPnP project
* http://miniupnp.free.fr/ or http://miniupnp.tuxfamily.org/
* (c) 2006-2011 Thomas Bernard
* This software is subject to the conditions detailed
* in the LICENCE file provided within the distribution */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <sys/errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <dlfcn.h>
#include <xtables.h>
#include <linux/netfilter/xt_DSCP.h>
#include <libiptc/libiptc.h>
#include <linux/version.h>
#if IPTABLES_143
/* IPTABLES API version >= 1.4.3 */
/* added in order to compile on gentoo :
* http://miniupnp.tuxfamily.org/forum/viewtopic.php?p=2183 */
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
#define __must_be_array(a) \
BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
#define LIST_POISON2 ((void *) 0x00200200 )
#if 0
#include <linux/netfilter/nf_nat.h>
#else
#include "tiny_nf_nat.h"
#endif
#define ip_nat_multi_range nf_nat_multi_range
#define ip_nat_range nf_nat_range
#define IPTC_HANDLE struct iptc_handle *
#else
/* IPTABLES API version < 1.4.3 */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
#include <linux/netfilter_ipv4/ip_nat.h>
#else
#if 0
#include <linux/netfilter/nf_nat.h>
#else
#include "tiny_nf_nat.h"
#endif
#endif
#define IPTC_HANDLE iptc_handle_t
#endif
/* IPT_ALIGN was renamed XT_ALIGN in iptables-1.4.11 */
#ifndef IPT_ALIGN
#define IPT_ALIGN XT_ALIGN
#endif
#include "../macros.h"
#include "../config.h"
#include "iptcrdr.h"
#include "../upnpglobalvars.h"
/* local functions declarations */
static int
addnatrule(int proto, unsigned short eport,
const char * iaddr, unsigned short iport,
const char * rhost);
static int
add_filter_rule(int proto, const char * rhost,
const char * iaddr, unsigned short iport);
static int
addpeernatrule(int proto,
const char * eaddr, unsigned short eport,
const char * iaddr, unsigned short iport,
const char * rhost, unsigned short rport);
static int
addpeerdscprule(int proto, unsigned char dscp,
const char * iaddr, unsigned short iport,
const char * rhost, unsigned short rport);
/* dummy init and shutdown functions */
int init_redirect(void)
{
return 0;
}
void shutdown_redirect(void)
{
return;
}
/* convert an ip address to string */
static int snprintip(char * dst, size_t size, uint32_t ip)
{
return snprintf(dst, size,
"%u.%u.%u.%u", ip >> 24, (ip >> 16) & 0xff,
(ip >> 8) & 0xff, ip & 0xff);
}
/* netfilter cannot store redirection descriptions, so we use our
* own structure to store them */
struct rdr_desc {
struct rdr_desc * next;
unsigned int timestamp;
unsigned short eport;
short proto;
char str[];
};
/* pointer to the chained list where descriptions are stored */
static struct rdr_desc * rdr_desc_list = 0;
/* add a description to the list of redirection descriptions */
static void
add_redirect_desc(unsigned short eport, int proto,
const char * desc, unsigned int timestamp)
{
struct rdr_desc * p;
size_t l;
/* set a default description if none given */
if(!desc)
desc = "miniupnpd";
l = strlen(desc) + 1;
p = malloc(sizeof(struct rdr_desc) + l);
if(p)
{
p->next = rdr_desc_list;
p->timestamp = timestamp;
p->eport = eport;
p->proto = (short)proto;
memcpy(p->str, desc, l);
rdr_desc_list = p;
}
}
/* delete a description from the list */
static void
del_redirect_desc(unsigned short eport, int proto)
{
struct rdr_desc * p, * last;
p = rdr_desc_list;
last = 0;
while(p)
{
if(p->eport == eport && p->proto == proto)
{
if(!last)
rdr_desc_list = p->next;
else
last->next = p->next;
free(p);
return;
}
last = p;
p = p->next;
}
}
/* go through the list to find the description */
static void
get_redirect_desc(unsigned short eport, int proto,
char * desc, int desclen,
unsigned int * timestamp)
{
struct rdr_desc * p;
for(p = rdr_desc_list; p; p = p->next)
{
if(p->eport == eport && p->proto == (short)proto)
{
if(desc)
strncpy(desc, p->str, desclen);
if(timestamp)
*timestamp = p->timestamp;
return;
}
}
/* if no description was found, return miniupnpd as default */
if(desc)
strncpy(desc, "miniupnpd", desclen);
if(timestamp)
*timestamp = 0;
}
#if USE_INDEX_FROM_DESC_LIST
static int
get_redirect_desc_by_index(int index, unsigned short * eport, int * proto,
char * desc, int desclen, unsigned int * timestamp)
{
int i = 0;
struct rdr_desc * p;
if(!desc || (desclen == 0))
return -1;
for(p = rdr_desc_list; p; p = p->next, i++)
{
if(i == index)
{
*eport = p->eport;
*proto = (int)p->proto;
strncpy(desc, p->str, desclen);
if(timestamp)
*timestamp = p->timestamp;
return 0;
}
}
return -1;
}
#endif
/* add_redirect_rule2() */
int
add_redirect_rule2(const char * ifname,
const char * rhost, unsigned short eport,
const char * iaddr, unsigned short iport, int proto,
const char * desc, unsigned int timestamp)
{
int r;
UNUSED(ifname);
r = addnatrule(proto, eport, iaddr, iport, rhost);
if(r >= 0)
add_redirect_desc(eport, proto, desc, timestamp);
return r;
}
/* add_redirect_rule2() */
int
add_peer_redirect_rule2(const char * ifname,
const char * rhost, unsigned short rport,
const char * eaddr, unsigned short eport,
const char * iaddr, unsigned short iport, int proto,
const char * desc, unsigned int timestamp)
{
int r;
UNUSED(ifname);
r = addpeernatrule(proto, eaddr, eport, iaddr, iport, rhost, rport);
if(r >= 0)
add_redirect_desc(eport, proto, desc, timestamp);
return r;
}
int
add_peer_dscp_rule2(const char * ifname,
const char * rhost, unsigned short rport,
unsigned char dscp,
const char * iaddr, unsigned short iport, int proto,
const char * desc, unsigned int timestamp)
{
int r;
UNUSED(ifname);
UNUSED(desc);
UNUSED(timestamp);
r = addpeerdscprule(proto, dscp, iaddr, iport, rhost, rport);
/* if(r >= 0)
add_redirect_desc(dscp, proto, desc, timestamp); */
return r;
}
int
add_filter_rule2(const char * ifname,
const char * rhost, const char * iaddr,
unsigned short eport, unsigned short iport,
int proto, const char * desc)
{
UNUSED(ifname);
UNUSED(eport);
UNUSED(desc);
return add_filter_rule(proto, rhost, iaddr, iport);
}
/* get_redirect_rule()
* returns -1 if the rule is not found */
int
get_redirect_rule(const char * ifname, unsigned short eport, int proto,
char * iaddr, int iaddrlen, unsigned short * iport,
char * desc, int desclen,
char * rhost, int rhostlen,
unsigned int * timestamp,
u_int64_t * packets, u_int64_t * bytes)
{
return get_nat_redirect_rule(miniupnpd_nat_chain, ifname, eport, proto, iaddr, iaddrlen, iport,
desc, desclen, rhost, rhostlen,timestamp, packets, bytes);
}
int
get_nat_redirect_rule(const char * nat_chain_name, const char * ifname, unsigned short eport, int proto,
char * iaddr, int iaddrlen, unsigned short * iport,
char * desc, int desclen,
char * rhost, int rhostlen,
unsigned int * timestamp,
u_int64_t * packets, u_int64_t * bytes)
{
int r = -1;
IPTC_HANDLE h;
const struct ipt_entry * e;
const struct ipt_entry_target * target;
const struct ip_nat_multi_range * mr;
const struct ipt_entry_match *match;
UNUSED(ifname);
h = iptc_init("nat");
if(!h)
{
syslog(LOG_ERR, "get_redirect_rule() : "
"iptc_init() failed : %s",
iptc_strerror(errno));
return -1;
}
if(!iptc_is_chain(nat_chain_name, h))
{
syslog(LOG_ERR, "chain %s not found", nat_chain_name);
}
else
{
#ifdef IPTABLES_143
for(e = iptc_first_rule(nat_chain_name, h);
e;
e = iptc_next_rule(e, h))
#else
for(e = iptc_first_rule(nat_chain_name, &h);
e;
e = iptc_next_rule(e, &h))
#endif
{
if(proto==e->ip.proto)
{
match = (const struct ipt_entry_match *)&e->elems;
if(0 == strncmp(match->u.user.name, "tcp", IPT_FUNCTION_MAXNAMELEN))
{
const struct ipt_tcp * info;
info = (const struct ipt_tcp *)match->data;
if(eport != info->dpts[0])
continue;
}
else
{
const struct ipt_udp * info;
info = (const struct ipt_udp *)match->data;
if(eport != info->dpts[0])
continue;
}
target = (void *)e + e->target_offset;
/* target = ipt_get_target(e); */
mr = (const struct ip_nat_multi_range *)&target->data[0];
snprintip(iaddr, iaddrlen, ntohl(mr->range[0].min_ip));
*iport = ntohs(mr->range[0].min.all);
get_redirect_desc(eport, proto, desc, desclen, timestamp);
if(packets)
*packets = e->counters.pcnt;
if(bytes)
*bytes = e->counters.bcnt;
/* rhost */
if(e->ip.src.s_addr && rhost) {
snprintip(rhost, rhostlen, ntohl(e->ip.src.s_addr));
}
r = 0;
break;
}
}
}
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
return r;
}
/* get_redirect_rule_by_index()
* return -1 when the rule was not found */
int
get_redirect_rule_by_index(int index,
char * ifname, unsigned short * eport,
char * iaddr, int iaddrlen, unsigned short * iport,
int * proto, char * desc, int desclen,
char * rhost, int rhostlen,
unsigned int * timestamp,
u_int64_t * packets, u_int64_t * bytes)
{
int r = -1;
#if USE_INDEX_FROM_DESC_LIST
r = get_redirect_desc_by_index(index, eport, proto,
desc, desclen, timestamp);
if (r==0)
{
r = get_redirect_rule(ifname, *eport, *proto, iaddr, iaddrlen, iport,
0, 0, packets, bytes);
}
#else
int i = 0;
IPTC_HANDLE h;
const struct ipt_entry * e;
const struct ipt_entry_target * target;
const struct ip_nat_multi_range * mr;
const struct ipt_entry_match *match;
UNUSED(ifname);
h = iptc_init("nat");
if(!h)
{
syslog(LOG_ERR, "get_redirect_rule_by_index() : "
"iptc_init() failed : %s",
iptc_strerror(errno));
return -1;
}
if(!iptc_is_chain(miniupnpd_nat_chain, h))
{
syslog(LOG_ERR, "chain %s not found", miniupnpd_nat_chain);
}
else
{
#ifdef IPTABLES_143
for(e = iptc_first_rule(miniupnpd_nat_chain, h);
e;
e = iptc_next_rule(e, h))
#else
for(e = iptc_first_rule(miniupnpd_nat_chain, &h);
e;
e = iptc_next_rule(e, &h))
#endif
{
if(i==index)
{
*proto = e->ip.proto;
match = (const struct ipt_entry_match *)&e->elems;
if(0 == strncmp(match->u.user.name, "tcp", IPT_FUNCTION_MAXNAMELEN))
{
const struct ipt_tcp * info;
info = (const struct ipt_tcp *)match->data;
*eport = info->dpts[0];
}
else
{
const struct ipt_udp * info;
info = (const struct ipt_udp *)match->data;
*eport = info->dpts[0];
}
target = (void *)e + e->target_offset;
mr = (const struct ip_nat_multi_range *)&target->data[0];
snprintip(iaddr, iaddrlen, ntohl(mr->range[0].min_ip));
*iport = ntohs(mr->range[0].min.all);
get_redirect_desc(*eport, *proto, desc, desclen, timestamp);
if(packets)
*packets = e->counters.pcnt;
if(bytes)
*bytes = e->counters.bcnt;
/* rhost */
if(rhost && rhostlen > 0) {
if(e->ip.src.s_addr) {
snprintip(rhost, rhostlen, ntohl(e->ip.src.s_addr));
} else {
rhost[0] = '\0';
}
}
r = 0;
break;
}
i++;
}
}
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
#endif
return r;
}
/* get_peer_rule_by_index()
* return -1 when the rule was not found */
int
get_peer_rule_by_index(int index,
char * ifname, unsigned short * eport,
char * iaddr, int iaddrlen, unsigned short * iport,
int * proto, char * desc, int desclen,
char * rhost, int rhostlen, unsigned short * rport,
unsigned int * timestamp,
u_int64_t * packets, u_int64_t * bytes)
{
int r = -1;
#if USE_INDEX_FROM_DESC_LIST && 0
r = get_redirect_desc_by_index(index, eport, proto,
desc, desclen, timestamp);
if (r==0)
{
r = get_redirect_rule(ifname, *eport, *proto, iaddr, iaddrlen, iport,
0, 0, packets, bytes);
}
#else
int i = 0;
IPTC_HANDLE h;
const struct ipt_entry * e;
const struct ipt_entry_target * target;
const struct ip_nat_multi_range * mr;
const struct ipt_entry_match *match;
UNUSED(ifname);
h = iptc_init("nat");
if(!h)
{
syslog(LOG_ERR, "get_peer_rule_by_index() : "
"iptc_init() failed : %s",
iptc_strerror(errno));
return -1;
}
if(!iptc_is_chain(miniupnpd_peer_chain, h))
{
syslog(LOG_ERR, "chain %s not found", miniupnpd_peer_chain);
}
else
{
#ifdef IPTABLES_143
for(e = iptc_first_rule(miniupnpd_peer_chain, h);
e;
e = iptc_next_rule(e, h))
#else
for(e = iptc_first_rule(miniupnpd_peer_chain, &h);
e;
e = iptc_next_rule(e, &h))
#endif
{
if(i==index)
{
*proto = e->ip.proto;
match = (const struct ipt_entry_match *)&e->elems;
if(0 == strncmp(match->u.user.name, "tcp", IPT_FUNCTION_MAXNAMELEN))
{
const struct ipt_tcp * info;
info = (const struct ipt_tcp *)match->data;
if (rport)
*rport = info->dpts[0];
if (iport)
*iport = info->spts[0];
}
else
{
const struct ipt_udp * info;
info = (const struct ipt_udp *)match->data;
if (rport)
*rport = info->dpts[0];
if (iport)
*iport = info->spts[0];
}
target = (void *)e + e->target_offset;
mr = (const struct ip_nat_multi_range *)&target->data[0];
*eport = ntohs(mr->range[0].min.all);
get_redirect_desc(*eport, *proto, desc, desclen, timestamp);
if(packets)
*packets = e->counters.pcnt;
if(bytes)
*bytes = e->counters.bcnt;
/* rhost */
if(rhost && rhostlen > 0) {
if(e->ip.dst.s_addr) {
snprintip(rhost, rhostlen, ntohl(e->ip.dst.s_addr));
} else {
rhost[0] = '\0';
}
}
if(iaddr && iaddrlen > 0) {
if(e->ip.src.s_addr) {
snprintip(iaddr, iaddrlen, ntohl(e->ip.src.s_addr));
} else {
rhost[0] = '\0';
}
}
r = 0;
break;
}
i++;
}
}
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
#endif
return r;
}
/* delete_rule_and_commit() :
* subfunction used in delete_redirect_and_filter_rules() */
static int
delete_rule_and_commit(unsigned int index, IPTC_HANDLE h,
const char * miniupnpd_chain,
const char * logcaller)
{
int r = 0;
#ifdef IPTABLES_143
if(!iptc_delete_num_entry(miniupnpd_chain, index, h))
#else
if(!iptc_delete_num_entry(miniupnpd_chain, index, &h))
#endif
{
syslog(LOG_ERR, "%s() : iptc_delete_num_entry(): %s\n",
logcaller, iptc_strerror(errno));
r = -1;
}
#ifdef IPTABLES_143
else if(!iptc_commit(h))
#else
else if(!iptc_commit(&h))
#endif
{
syslog(LOG_ERR, "%s() : iptc_commit(): %s\n",
logcaller, iptc_strerror(errno));
r = -1;
}
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
return r;
}
/* delete_redirect_and_filter_rules()
*/
int
delete_redirect_and_filter_rules(unsigned short eport, int proto)
{
int r = -1, r2 = -1;
unsigned index = 0;
unsigned i = 0;
IPTC_HANDLE h;
const struct ipt_entry * e;
const struct ipt_entry_target * target;
const struct ip_nat_multi_range * mr;
const struct ipt_entry_match *match;
unsigned short iport = 0;
uint32_t iaddr = 0;
h = iptc_init("nat");
if(!h)
{
syslog(LOG_ERR, "delete_redirect_and_filter_rules() : "
"iptc_init() failed : %s",
iptc_strerror(errno));
return -1;
}
/* First step : find the right nat rule */
if(!iptc_is_chain(miniupnpd_nat_chain, h))
{
syslog(LOG_ERR, "chain %s not found", miniupnpd_nat_chain);
}
else
{
#ifdef IPTABLES_143
for(e = iptc_first_rule(miniupnpd_nat_chain, h);
e;
e = iptc_next_rule(e, h), i++)
#else
for(e = iptc_first_rule(miniupnpd_nat_chain, &h);
e;
e = iptc_next_rule(e, &h), i++)
#endif
{
if(proto==e->ip.proto)
{
match = (const struct ipt_entry_match *)&e->elems;
if(0 == strncmp(match->u.user.name, "tcp", IPT_FUNCTION_MAXNAMELEN))
{
const struct ipt_tcp * info;
info = (const struct ipt_tcp *)match->data;
if(eport != info->dpts[0])
continue;
}
else
{
const struct ipt_udp * info;
info = (const struct ipt_udp *)match->data;
if(eport != info->dpts[0])
continue;
}
/* get the index, the internal address and the internal port
* of the rule */
index = i;
target = (void *)e + e->target_offset;
mr = (const struct ip_nat_multi_range *)&target->data[0];
iaddr = mr->range[0].min_ip;
iport = ntohs(mr->range[0].min.all);
r = 0;
break;
}
}
}
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
if(r == 0)
{
syslog(LOG_INFO, "Trying to delete nat rule at index %u", index);
/* Now delete both rules */
/* first delete the nat rule */
h = iptc_init("nat");
if(h)
{
r = delete_rule_and_commit(index, h, miniupnpd_nat_chain, "delete_redirect_rule");
}
if((r == 0) && (h = iptc_init("filter")))
{
i = 0;
/* we must find the right index for the filter rule */
#ifdef IPTABLES_143
for(e = iptc_first_rule(miniupnpd_forward_chain, h);
e;
e = iptc_next_rule(e, h), i++)
#else
for(e = iptc_first_rule(miniupnpd_forward_chain, &h);
e;
e = iptc_next_rule(e, &h), i++)
#endif
{
if(proto==e->ip.proto)
{
match = (const struct ipt_entry_match *)&e->elems;
/*syslog(LOG_DEBUG, "filter rule #%u: %s %s",
i, match->u.user.name, inet_ntoa(e->ip.dst));*/
if(0 == strncmp(match->u.user.name, "tcp", IPT_FUNCTION_MAXNAMELEN))
{
const struct ipt_tcp * info;
info = (const struct ipt_tcp *)match->data;
if(iport != info->dpts[0])
continue;
}
else
{
const struct ipt_udp * info;
info = (const struct ipt_udp *)match->data;
if(iport != info->dpts[0])
continue;
}
if(iaddr != e->ip.dst.s_addr)
continue;
index = i;
syslog(LOG_INFO, "Trying to delete filter rule at index %u", index);
r = delete_rule_and_commit(index, h, miniupnpd_forward_chain, "delete_filter_rule");
h = NULL;
break;
}
}
}
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
}
/*delete PEER rule*/
if((h = iptc_init("nat")))
{
i = 0;
/* we must find the right index for the filter rule */
#ifdef IPTABLES_143
for(e = iptc_first_rule(miniupnpd_peer_chain, h);
e;
e = iptc_next_rule(e, h), i++)
#else
for(e = iptc_first_rule(miniupnpd_peer_chain, &h);
e;
e = iptc_next_rule(e, &h), i++)
#endif
{
if(proto==e->ip.proto)
{
target = (void *)e + e->target_offset;
mr = (const struct ip_nat_multi_range *)&target->data[0];
if (eport != ntohs(mr->range[0].min.all)) {
continue;
}
iaddr = e->ip.src.s_addr;
match = (const struct ipt_entry_match *)&e->elems;
if(0 == strncmp(match->u.user.name, "tcp", IPT_FUNCTION_MAXNAMELEN))
{
const struct ipt_tcp * info;
info = (const struct ipt_tcp *)match->data;
iport = info->spts[0];
}
else
{
const struct ipt_udp * info;
info = (const struct ipt_udp *)match->data;
iport = info->dpts[0];
}
index = i;
syslog(LOG_INFO, "Trying to delete peer rule at index %u", index);
r2 = delete_rule_and_commit(index, h, miniupnpd_peer_chain, "delete_peer_rule");
h = NULL;
break;
}
}
}
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
/*delete DSCP rule*/
if((r2==0)&&(h = iptc_init("mangle")))
{
i = 0;
index = -1;
/* we must find the right index for the filter rule */
#ifdef IPTABLES_143
for(e = iptc_first_rule(miniupnpd_nat_chain, h);
e;
e = iptc_next_rule(e, h), i++)
#else
for(e = iptc_first_rule(miniupnpd_nat_chain, &h);
e;
e = iptc_next_rule(e, &h), i++)
#endif
{
if(proto==e->ip.proto)
{
match = (const struct ipt_entry_match *)&e->elems;
/*syslog(LOG_DEBUG, "filter rule #%u: %s %s",
i, match->u.user.name, inet_ntoa(e->ip.dst));*/
if(0 == strncmp(match->u.user.name, "tcp", IPT_FUNCTION_MAXNAMELEN))
{
const struct ipt_tcp * info;
info = (const struct ipt_tcp *)match->data;
if(iport != info->spts[0])
continue;
}
else
{
const struct ipt_udp * info;
info = (const struct ipt_udp *)match->data;
if(iport != info->spts[0])
continue;
}
if(iaddr != e->ip.src.s_addr)
continue;
index = i;
syslog(LOG_INFO, "Trying to delete dscp rule at index %u", index);
r2 = delete_rule_and_commit(index, h, miniupnpd_nat_chain, "delete_dscp_rule");
h = NULL;
break;
}
}
if (h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
}
del_redirect_desc(eport, proto);
return r*r2;
}
/* ==================================== */
/* TODO : add the -m state --state NEW,ESTABLISHED,RELATED
* only for the filter rule */
static struct ipt_entry_match *
get_tcp_match(unsigned short dport, unsigned short sport)
{
struct ipt_entry_match *match;
struct ipt_tcp * tcpinfo;
size_t size;
size = IPT_ALIGN(sizeof(struct ipt_entry_match))
+ IPT_ALIGN(sizeof(struct ipt_tcp));
match = calloc(1, size);
match->u.match_size = size;
strncpy(match->u.user.name, "tcp", sizeof(match->u.user.name));
tcpinfo = (struct ipt_tcp *)match->data;
if (sport == 0) {
tcpinfo->spts[0] = 0; /* all source ports */
tcpinfo->spts[1] = 0xFFFF;
} else {
tcpinfo->spts[0] = sport; /* specified source port */
tcpinfo->spts[1] = sport;
}
if (dport == 0) {
tcpinfo->dpts[0] = 0; /* all destination ports */
tcpinfo->dpts[1] = 0xFFFF;
} else {
tcpinfo->dpts[0] = dport; /* specified destination port */
tcpinfo->dpts[1] = dport;
}
return match;
}
static struct ipt_entry_match *
get_udp_match(unsigned short dport, unsigned short sport)
{
struct ipt_entry_match *match;
struct ipt_udp * udpinfo;
size_t size;
size = IPT_ALIGN(sizeof(struct ipt_entry_match))
+ IPT_ALIGN(sizeof(struct ipt_udp));
match = calloc(1, size);
match->u.match_size = size;
strncpy(match->u.user.name, "udp", sizeof(match->u.user.name));
udpinfo = (struct ipt_udp *)match->data;
if (sport == 0) {
udpinfo->spts[0] = 0; /* all source ports */
udpinfo->spts[1] = 0xFFFF;
} else {
udpinfo->spts[0] = sport; /* specified source port */
udpinfo->spts[1] = sport;
}
if (dport == 0) {
udpinfo->dpts[0] = 0; /* all destination ports */
udpinfo->dpts[1] = 0xFFFF;
} else {
udpinfo->dpts[0] = dport; /* specified destination port */
udpinfo->dpts[1] = dport;
}
return match;
}
static struct ipt_entry_target *
get_dnat_target(const char * daddr, unsigned short dport)
{
struct ipt_entry_target * target;
struct ip_nat_multi_range * mr;
struct ip_nat_range * range;
size_t size;
size = IPT_ALIGN(sizeof(struct ipt_entry_target))
+ IPT_ALIGN(sizeof(struct ip_nat_multi_range));
target = calloc(1, size);
target->u.target_size = size;
strncpy(target->u.user.name, "DNAT", sizeof(target->u.user.name));
/* one ip_nat_range already included in ip_nat_multi_range */
mr = (struct ip_nat_multi_range *)&target->data[0];
mr->rangesize = 1;
range = &mr->range[0];
range->min_ip = range->max_ip = inet_addr(daddr);
range->flags |= IP_NAT_RANGE_MAP_IPS;
range->min.all = range->max.all = htons(dport);
range->flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
return target;
}
static struct ipt_entry_target *
get_snat_target(const char * saddr, unsigned short sport)
{
struct ipt_entry_target * target;
struct ip_nat_multi_range * mr;
struct ip_nat_range * range;
size_t size;
size = IPT_ALIGN(sizeof(struct ipt_entry_target))
+ IPT_ALIGN(sizeof(struct ip_nat_multi_range));
target = calloc(1, size);
target->u.target_size = size;
strncpy(target->u.user.name, "SNAT", sizeof(target->u.user.name));
/* one ip_nat_range already included in ip_nat_multi_range */
mr = (struct ip_nat_multi_range *)&target->data[0];
mr->rangesize = 1;
range = &mr->range[0];
range->min_ip = range->max_ip = inet_addr(saddr);
range->flags |= IP_NAT_RANGE_MAP_IPS;
range->min.all = range->max.all = htons(sport);
range->flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
return target;
}
static struct ipt_entry_target *
get_dscp_target(unsigned char dscp)
{
struct ipt_entry_target * target;
struct xt_DSCP_info * di;
size_t size;
size = IPT_ALIGN(sizeof(struct ipt_entry_target))
+ IPT_ALIGN(sizeof(struct xt_DSCP_info));
target = calloc(1, size);
target->u.target_size = size;
strncpy(target->u.user.name, "DSCP", sizeof(target->u.user.name));
/* one ip_nat_range already included in ip_nat_multi_range */
di = (struct xt_DSCP_info *)&target->data[0];
di->dscp=dscp;
return target;
}
/* iptc_init_verify_and_append()
* return 0 on success, -1 on failure */
static int
iptc_init_verify_and_append(const char * table,
const char * miniupnpd_chain,
struct ipt_entry * e,
const char * logcaller)
{
IPTC_HANDLE h;
h = iptc_init(table);
if(!h)
{
syslog(LOG_ERR, "%s : iptc_init() error : %s\n",
logcaller, iptc_strerror(errno));
return -1;
}
if(!iptc_is_chain(miniupnpd_chain, h))
{
syslog(LOG_ERR, "%s : chain %s not found",
logcaller, miniupnpd_chain);
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
return -1;
}
/* iptc_insert_entry(miniupnpd_chain, e, n, h/&h) could also be used */
#ifdef IPTABLES_143
if(!iptc_append_entry(miniupnpd_chain, e, h))
#else
if(!iptc_append_entry(miniupnpd_chain, e, &h))
#endif
{
syslog(LOG_ERR, "%s : iptc_append_entry() error : %s\n",
logcaller, iptc_strerror(errno));
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
return -1;
}
#ifdef IPTABLES_143
if(!iptc_commit(h))
#else
if(!iptc_commit(&h))
#endif
{
syslog(LOG_ERR, "%s : iptc_commit() error : %s\n",
logcaller, iptc_strerror(errno));
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
return -1;
}
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
return 0;
}
/* add nat rule
* iptables -t nat -A MINIUPNPD -p proto --dport eport -j DNAT --to iaddr:iport
* */
static int
addnatrule(int proto, unsigned short eport,
const char * iaddr, unsigned short iport,
const char * rhost)
{
int r = 0;
struct ipt_entry * e;
struct ipt_entry_match *match = NULL;
struct ipt_entry_target *target = NULL;
e = calloc(1, sizeof(struct ipt_entry));
e->ip.proto = proto;
if(proto == IPPROTO_TCP)
{
match = get_tcp_match(eport, 0);
}
else
{
match = get_udp_match(eport, 0);
}
e->nfcache = NFC_IP_DST_PT;
target = get_dnat_target(iaddr, iport);
e->nfcache |= NFC_UNKNOWN;
e = realloc(e, sizeof(struct ipt_entry)
+ match->u.match_size
+ target->u.target_size);
memcpy(e->elems, match, match->u.match_size);
memcpy(e->elems + match->u.match_size, target, target->u.target_size);
e->target_offset = sizeof(struct ipt_entry)
+ match->u.match_size;
e->next_offset = sizeof(struct ipt_entry)
+ match->u.match_size
+ target->u.target_size;
/* remote host */
if(rhost && (rhost[0] != '\0') && (0 != strcmp(rhost, "*")))
{
e->ip.src.s_addr = inet_addr(rhost);
e->ip.smsk.s_addr = INADDR_NONE;
}
r = iptc_init_verify_and_append("nat", miniupnpd_nat_chain, e, "addnatrule()");
free(target);
free(match);
free(e);
return r;
}
/* iptables -t nat -A MINIUPNPD-PCP-PEER -s iaddr -d rhost
* -p proto --sport iport --dport rport -j SNAT
* --to-source ext_ip:eport */
static int
addpeernatrule(int proto,
const char * eaddr, unsigned short eport,
const char * iaddr, unsigned short iport,
const char * rhost, unsigned short rport)
{
int r = 0;
struct ipt_entry * e;
struct ipt_entry_match *match = NULL;
struct ipt_entry_target *target = NULL;
e = calloc(1, sizeof(struct ipt_entry));
e->ip.proto = proto;
/* TODO: Fill port matches and SNAT */
if(proto == IPPROTO_TCP)
{
match = get_tcp_match(rport, iport);
}
else
{
match = get_udp_match(rport, iport);
}
e->nfcache = NFC_IP_DST_PT | NFC_IP_SRC_PT;
target = get_snat_target(eaddr, eport);
e->nfcache |= NFC_UNKNOWN;
e = realloc(e, sizeof(struct ipt_entry)
+ match->u.match_size
+ target->u.target_size);
memcpy(e->elems, match, match->u.match_size);
memcpy(e->elems + match->u.match_size, target, target->u.target_size);
e->target_offset = sizeof(struct ipt_entry)
+ match->u.match_size;
e->next_offset = sizeof(struct ipt_entry)
+ match->u.match_size
+ target->u.target_size;
/* internal host */
if(iaddr && (iaddr[0] != '\0') && (0 != strcmp(iaddr, "*")))
{
e->ip.src.s_addr = inet_addr(iaddr);
e->ip.smsk.s_addr = INADDR_NONE;
}
/* remote host */
if(rhost && (rhost[0] != '\0') && (0 != strcmp(rhost, "*")))
{
e->ip.dst.s_addr = inet_addr(rhost);
e->ip.dmsk.s_addr = INADDR_NONE;
}
r = iptc_init_verify_and_append("nat", miniupnpd_peer_chain, e, "addpeernatrule()");
free(target);
free(match);
free(e);
return r;
}
/* iptables -t mangle -A MINIUPNPD -s iaddr -d rhost
* -p proto --sport iport --dport rport -j DSCP
* --set-dscp 0xXXXX */
static int
addpeerdscprule(int proto, unsigned char dscp,
const char * iaddr, unsigned short iport,
const char * rhost, unsigned short rport)
{
int r = 0;
struct ipt_entry * e;
struct ipt_entry_match *match = NULL;
struct ipt_entry_target *target = NULL;
e = calloc(1, sizeof(struct ipt_entry));
e->ip.proto = proto;
/* TODO: Fill port matches and SNAT */
if(proto == IPPROTO_TCP)
{
match = get_tcp_match(rport, iport);
}
else
{
match = get_udp_match(rport, iport);
}
e->nfcache = NFC_IP_DST_PT | NFC_IP_SRC_PT;
target = get_dscp_target(dscp);
e->nfcache |= NFC_UNKNOWN;
e = realloc(e, sizeof(struct ipt_entry)
+ match->u.match_size
+ target->u.target_size);
memcpy(e->elems, match, match->u.match_size);
memcpy(e->elems + match->u.match_size, target, target->u.target_size);
e->target_offset = sizeof(struct ipt_entry)
+ match->u.match_size;
e->next_offset = sizeof(struct ipt_entry)
+ match->u.match_size
+ target->u.target_size;
/* internal host */
if(iaddr && (iaddr[0] != '\0') && (0 != strcmp(iaddr, "*")))
{
e->ip.src.s_addr = inet_addr(iaddr);
e->ip.smsk.s_addr = INADDR_NONE;
}
/* remote host */
if(rhost && (rhost[0] != '\0') && (0 != strcmp(rhost, "*")))
{
e->ip.dst.s_addr = inet_addr(rhost);
e->ip.dmsk.s_addr = INADDR_NONE;
}
r = iptc_init_verify_and_append("mangle", miniupnpd_nat_chain, e,
"addpeerDSCPrule()");
free(target);
free(match);
free(e);
return r;
}
/* ================================= */
static struct ipt_entry_target *
get_accept_target(void)
{
struct ipt_entry_target * target = NULL;
size_t size;
size = IPT_ALIGN(sizeof(struct ipt_entry_target))
+ IPT_ALIGN(sizeof(int));
target = calloc(1, size);
target->u.user.target_size = size;
strncpy(target->u.user.name, "ACCEPT", sizeof(target->u.user.name));
return target;
}
/* add_filter_rule()
* */
static int
add_filter_rule(int proto, const char * rhost,
const char * iaddr, unsigned short iport)
{
int r = 0;
struct ipt_entry * e;
struct ipt_entry_match *match = NULL;
struct ipt_entry_target *target = NULL;
e = calloc(1, sizeof(struct ipt_entry));
e->ip.proto = proto;
if(proto == IPPROTO_TCP)
{
match = get_tcp_match(iport,0);
}
else
{
match = get_udp_match(iport,0);
}
e->nfcache = NFC_IP_DST_PT;
e->ip.dst.s_addr = inet_addr(iaddr);
e->ip.dmsk.s_addr = INADDR_NONE;
target = get_accept_target();
e->nfcache |= NFC_UNKNOWN;
e = realloc(e, sizeof(struct ipt_entry)
+ match->u.match_size
+ target->u.target_size);
memcpy(e->elems, match, match->u.match_size);
memcpy(e->elems + match->u.match_size, target, target->u.target_size);
e->target_offset = sizeof(struct ipt_entry)
+ match->u.match_size;
e->next_offset = sizeof(struct ipt_entry)
+ match->u.match_size
+ target->u.target_size;
/* remote host */
if(rhost && (rhost[0] != '\0') && (0 != strcmp(rhost, "*")))
{
e->ip.src.s_addr = inet_addr(rhost);
e->ip.smsk.s_addr = INADDR_NONE;
}
r = iptc_init_verify_and_append("filter", miniupnpd_forward_chain, e, "add_filter_rule()");
free(target);
free(match);
free(e);
return r;
}
/* return an (malloc'ed) array of "external" port for which there is
* a port mapping. number is the size of the array */
unsigned short *
get_portmappings_in_range(unsigned short startport, unsigned short endport,
int proto, unsigned int * number)
{
unsigned short * array;
unsigned int capacity;
unsigned short eport;
IPTC_HANDLE h;
const struct ipt_entry * e;
const struct ipt_entry_match *match;
*number = 0;
capacity = 128;
array = calloc(capacity, sizeof(unsigned short));
if(!array)
{
syslog(LOG_ERR, "get_portmappings_in_range() : calloc error");
return NULL;
}
h = iptc_init("nat");
if(!h)
{
syslog(LOG_ERR, "get_redirect_rule_by_index() : "
"iptc_init() failed : %s",
iptc_strerror(errno));
free(array);
return NULL;
}
if(!iptc_is_chain(miniupnpd_nat_chain, h))
{
syslog(LOG_ERR, "chain %s not found", miniupnpd_nat_chain);
free(array);
array = NULL;
}
else
{
#ifdef IPTABLES_143
for(e = iptc_first_rule(miniupnpd_nat_chain, h);
e;
e = iptc_next_rule(e, h))
#else
for(e = iptc_first_rule(miniupnpd_nat_chain, &h);
e;
e = iptc_next_rule(e, &h))
#endif
{
if(proto == e->ip.proto)
{
match = (const struct ipt_entry_match *)&e->elems;
if(0 == strncmp(match->u.user.name, "tcp", IPT_FUNCTION_MAXNAMELEN))
{
const struct ipt_tcp * info;
info = (const struct ipt_tcp *)match->data;
eport = info->dpts[0];
}
else
{
const struct ipt_udp * info;
info = (const struct ipt_udp *)match->data;
eport = info->dpts[0];
}
if(startport <= eport && eport <= endport)
{
if(*number >= capacity)
{
/* need to increase the capacity of the array */
array = realloc(array, sizeof(unsigned short)*capacity);
if(!array)
{
syslog(LOG_ERR, "get_portmappings_in_range() : realloc(%u) error",
(unsigned)sizeof(unsigned short)*capacity);
*number = 0;
break;
}
array[*number] = eport;
(*number)++;
}
}
}
}
}
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
return array;
}
/* ================================ */
#ifdef DEBUG
static int
print_match(const struct ipt_entry_match *match)
{
printf("match %s\n", match->u.user.name);
if(0 == strncmp(match->u.user.name, "tcp", IPT_FUNCTION_MAXNAMELEN))
{
struct ipt_tcp * tcpinfo;
tcpinfo = (struct ipt_tcp *)match->data;
printf("srcport = %hu:%hu dstport = %hu:%hu\n",
tcpinfo->spts[0], tcpinfo->spts[1],
tcpinfo->dpts[0], tcpinfo->dpts[1]);
}
else if(0 == strncmp(match->u.user.name, "udp", IPT_FUNCTION_MAXNAMELEN))
{
struct ipt_udp * udpinfo;
udpinfo = (struct ipt_udp *)match->data;
printf("srcport = %hu:%hu dstport = %hu:%hu\n",
udpinfo->spts[0], udpinfo->spts[1],
udpinfo->dpts[0], udpinfo->dpts[1]);
}
return 0;
}
static void
print_iface(const char * iface, const unsigned char * mask, int invert)
{
unsigned i;
if(mask[0] == 0)
return;
if(invert)
printf("! ");
for(i=0; i<IFNAMSIZ; i++)
{
if(mask[i])
{
if(iface[i])
putchar(iface[i]);
}
else
{
if(iface[i-1])
putchar('+');
break;
}
}
}
static void
printip(uint32_t ip)
{
printf("%u.%u.%u.%u", ip >> 24, (ip >> 16) & 0xff,
(ip >> 8) & 0xff, ip & 0xff);
}
/* for debug */
/* read the "filter" and "nat" tables */
int
list_redirect_rule(const char * ifname)
{
IPTC_HANDLE h;
const struct ipt_entry * e;
const struct ipt_entry_target * target;
const struct ip_nat_multi_range * mr;
const char * target_str;
char addr[16], mask[16];
(void)ifname;
h = iptc_init("nat");
if(!h)
{
printf("iptc_init() error : %s\n", iptc_strerror(errno));
return -1;
}
if(!iptc_is_chain(miniupnpd_nat_chain, h))
{
printf("chain %s not found\n", miniupnpd_nat_chain);
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
return -1;
}
#ifdef IPTABLES_143
for(e = iptc_first_rule(miniupnpd_nat_chain, h);
e;
e = iptc_next_rule(e, h))
{
target_str = iptc_get_target(e, h);
#else
for(e = iptc_first_rule(miniupnpd_nat_chain, &h);
e;
e = iptc_next_rule(e, &h))
{
target_str = iptc_get_target(e, &h);
#endif
printf("===\n");
inet_ntop(AF_INET, &e->ip.src, addr, sizeof(addr));
inet_ntop(AF_INET, &e->ip.smsk, mask, sizeof(mask));
printf("src = %s%s/%s\n", (e->ip.invflags & IPT_INV_SRCIP)?"! ":"",
/*inet_ntoa(e->ip.src), inet_ntoa(e->ip.smsk)*/
addr, mask);
inet_ntop(AF_INET, &e->ip.dst, addr, sizeof(addr));
inet_ntop(AF_INET, &e->ip.dmsk, mask, sizeof(mask));
printf("dst = %s%s/%s\n", (e->ip.invflags & IPT_INV_DSTIP)?"! ":"",
/*inet_ntoa(e->ip.dst), inet_ntoa(e->ip.dmsk)*/
addr, mask);
/*printf("in_if = %s out_if = %s\n", e->ip.iniface, e->ip.outiface);*/
printf("in_if = ");
print_iface(e->ip.iniface, e->ip.iniface_mask,
e->ip.invflags & IPT_INV_VIA_IN);
printf(" out_if = ");
print_iface(e->ip.outiface, e->ip.outiface_mask,
e->ip.invflags & IPT_INV_VIA_OUT);
printf("\n");
printf("ip.proto = %s%d\n", (e->ip.invflags & IPT_INV_PROTO)?"! ":"",
e->ip.proto);
/* display matches stuff */
if(e->target_offset)
{
IPT_MATCH_ITERATE(e, print_match);
/*printf("\n");*/
}
printf("target = %s\n", target_str);
target = (void *)e + e->target_offset;
mr = (const struct ip_nat_multi_range *)&target->data[0];
printf("ips ");
printip(ntohl(mr->range[0].min_ip));
printf(" ");
printip(ntohl(mr->range[0].max_ip));
printf("\nports %hu %hu\n", ntohs(mr->range[0].min.all),
ntohs(mr->range[0].max.all));
printf("flags = %x\n", mr->range[0].flags);
}
if(h)
#ifdef IPTABLES_143
iptc_free(h);
#else
iptc_free(&h);
#endif
return 0;
}
#endif
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