miniupnp/miniupnpd/upnpredirect.c

791 lines
21 KiB
C

/* $Id: upnpredirect.c,v 1.97 2020/06/06 17:55:24 nanard Exp $ */
/* vim: tabstop=4 shiftwidth=4 noexpandtab
* MiniUPnP project
* http://miniupnp.free.fr/ or https://miniupnp.tuxfamily.org/
* (c) 2006-2020 Thomas Bernard
* This software is subject to the conditions detailed
* in the LICENCE file provided within the distribution */
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <net/if.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <ctype.h>
#include <unistd.h>
#include "macros.h"
#include "config.h"
#include "upnpredirect.h"
#include "upnpglobalvars.h"
#include "upnpevents.h"
#include "portinuse.h"
#include "upnputils.h"
#if defined(USE_NETFILTER)
#include "netfilter/iptcrdr.h"
#endif
#if defined(USE_PF)
#include "pf/obsdrdr.h"
#endif
#if defined(USE_IPF)
#include "ipf/ipfrdr.h"
#endif
#if defined(USE_IPFW)
#include "ipfw/ipfwrdr.h"
#endif
#ifdef USE_MINIUPNPDCTL
#include <stdio.h>
#include <unistd.h>
#endif
#ifdef ENABLE_LEASEFILE
#include <sys/stat.h>
#endif
/* from <inttypes.h> */
#ifndef PRIu64
#define PRIu64 "llu"
#endif
/* proto_atoi()
* convert the string "UDP" or "TCP" to IPPROTO_UDP and IPPROTO_UDP */
static int
proto_atoi(const char * protocol)
{
int proto = IPPROTO_TCP;
if(strcasecmp(protocol, "UDP") == 0)
proto = IPPROTO_UDP;
#ifdef IPPROTO_UDPLITE
else if(strcasecmp(protocol, "UDPLITE") == 0)
proto = IPPROTO_UDPLITE;
#endif /* IPPROTO_UDPLITE */
return proto;
}
/* proto_itoa()
* convert IPPROTO_UDP, IPPROTO_UDP, etc. to "UDP", "TCP" */
static const char *
proto_itoa(int proto)
{
const char * protocol;
switch(proto) {
case IPPROTO_UDP:
protocol = "UDP";
break;
case IPPROTO_TCP:
protocol = "TCP";
break;
#ifdef IPPROTO_UDPLITE
case IPPROTO_UDPLITE:
protocol = "UDPLITE";
break;
#endif /* IPPROTO_UDPLITE */
default:
protocol = "*UNKNOWN*";
}
return protocol;
}
#ifdef ENABLE_LEASEFILE
static int
lease_file_add(unsigned short eport,
const char * iaddr,
unsigned short iport,
int proto,
const char * desc,
unsigned int timestamp)
{
FILE * fd;
if (lease_file == NULL) return 0;
fd = fopen( lease_file, "a");
if (fd==NULL) {
syslog(LOG_ERR, "could not open lease file: %s", lease_file);
return -1;
}
/* convert our time to unix time
* if LEASEFILE_USE_REMAINING_TIME is defined, only the remaining time is stored */
if (timestamp != 0) {
timestamp -= upnp_time();
#ifndef LEASEFILE_USE_REMAINING_TIME
timestamp += time(NULL);
#endif
}
fprintf(fd, "%s:%hu:%s:%hu:%u:%s\n",
proto_itoa(proto), eport, iaddr, iport,
timestamp, desc);
fclose(fd);
return 0;
}
static int
lease_file_remove(unsigned short eport, int proto)
{
FILE* fd, *fdt;
int tmp;
char buf[512];
char str[32];
char tmpfilename[128];
int str_size, buf_size;
if (lease_file == NULL) return 0;
if (strlen( lease_file) + 7 > sizeof(tmpfilename)) {
syslog(LOG_ERR, "Lease filename is too long");
return -1;
}
snprintf( tmpfilename, sizeof(tmpfilename), "%sXXXXXX", lease_file);
fd = fopen( lease_file, "r");
if (fd==NULL) {
return 0;
}
snprintf( str, sizeof(str), "%s:%u", proto_itoa(proto), eport);
str_size = strlen(str);
tmp = mkstemp(tmpfilename);
if (tmp==-1) {
fclose(fd);
syslog(LOG_ERR, "could not open temporary lease file");
return -1;
}
fchmod(tmp, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
fdt = fdopen(tmp, "a");
buf[sizeof(buf)-1] = 0;
while( fgets(buf, sizeof(buf)-1, fd) != NULL) {
buf_size = strlen(buf);
if (buf_size < str_size || strncmp(str, buf, str_size)!=0) {
fwrite(buf, buf_size, 1, fdt);
}
}
fclose(fdt);
fclose(fd);
if (rename(tmpfilename, lease_file) < 0) {
syslog(LOG_ERR, "could not rename temporary lease file to %s", lease_file);
remove(tmpfilename);
}
return 0;
}
/* reload_from_lease_file()
* read lease_file and add the rules contained
*/
int reload_from_lease_file()
{
FILE * fd;
char * p;
unsigned short eport, iport;
char * proto;
char * iaddr;
char * desc;
char * rhost;
unsigned int leaseduration;
unsigned int timestamp;
time_t current_time;
#ifndef LEASEFILE_USE_REMAINING_TIME
time_t current_unix_time;
#endif
char line[128];
int r;
if(!lease_file) return -1;
fd = fopen( lease_file, "r");
if (fd==NULL) {
syslog(LOG_ERR, "could not open lease file: %s", lease_file);
return -1;
}
if(unlink(lease_file) < 0) {
syslog(LOG_WARNING, "could not unlink file %s : %m", lease_file);
}
current_time = upnp_time();
#ifndef LEASEFILE_USE_REMAINING_TIME
current_unix_time = time(NULL);
#endif
while(fgets(line, sizeof(line), fd)) {
syslog(LOG_DEBUG, "parsing lease file line '%s'", line);
proto = line;
p = strchr(line, ':');
if(!p) {
syslog(LOG_ERR, "unrecognized data in lease file");
continue;
}
*(p++) = '\0';
iaddr = strchr(p, ':');
if(!iaddr) {
syslog(LOG_ERR, "unrecognized data in lease file");
continue;
}
*(iaddr++) = '\0';
eport = (unsigned short)atoi(p);
p = strchr(iaddr, ':');
if(!p) {
syslog(LOG_ERR, "unrecognized data in lease file");
continue;
}
*(p++) = '\0';
iport = (unsigned short)atoi(p);
p = strchr(p, ':');
if(!p) {
syslog(LOG_ERR, "unrecognized data in lease file");
continue;
}
*(p++) = '\0';
desc = strchr(p, ':');
if(!desc) {
syslog(LOG_ERR, "unrecognized data in lease file");
continue;
}
*(desc++) = '\0';
/*timestamp = (unsigned int)atoi(p);*/
timestamp = (unsigned int)strtoul(p, NULL, 10);
/* trim description */
while(isspace(*desc))
desc++;
p = desc;
while(*(p+1))
p++;
while(isspace(*p) && (p > desc))
*(p--) = '\0';
if(timestamp > 0) {
#ifdef LEASEFILE_USE_REMAINING_TIME
leaseduration = timestamp;
timestamp += current_time; /* convert to our time */
#else
if(timestamp <= (unsigned int)current_unix_time) {
syslog(LOG_NOTICE, "already expired lease in lease file");
continue;
} else {
leaseduration = timestamp - current_unix_time;
timestamp = leaseduration + current_time; /* convert to our time */
}
#endif
} else {
leaseduration = 0; /* default value */
}
rhost = NULL;
r = upnp_redirect(rhost, eport, iaddr, iport, proto, desc, leaseduration);
if(r == -1) {
syslog(LOG_ERR, "Failed to redirect %hu -> %s:%hu protocol %s",
eport, iaddr, iport, proto);
} else if(r == -2) {
/* Add the redirection again to the lease file */
lease_file_add(eport, iaddr, iport, proto_atoi(proto),
desc, timestamp);
}
}
fclose(fd);
return 0;
}
#ifdef LEASEFILE_USE_REMAINING_TIME
void lease_file_rewrite(void)
{
int index;
unsigned short eport, iport;
int proto;
char iaddr[32];
char desc[64];
char rhost[40];
unsigned int timestamp;
if (lease_file == NULL) return;
remove(lease_file);
for(index = 0; ; index++) {
if(get_redirect_rule_by_index(index, 0/*ifname*/, &eport, iaddr, sizeof(iaddr),
&iport, &proto, desc, sizeof(desc),
rhost, sizeof(rhost), &timestamp,
0, 0) < 0)
break;
if(lease_file_add(eport, iaddr, iport, proto, desc, timestamp) < 0)
break;
}
}
#endif
#endif
/* upnp_redirect()
* calls OS/fw dependent implementation of the redirection.
* protocol should be the string "TCP" or "UDP"
* returns: 0 on success
* -1 failed to redirect
* -2 already redirected
* -3 permission check failed
* -4 already redirected (other mechanism)
*/
int
upnp_redirect(const char * rhost, unsigned short eport,
const char * iaddr, unsigned short iport,
const char * protocol, const char * desc,
unsigned int leaseduration)
{
int proto, r;
char iaddr_old[32];
char rhost_old[32];
unsigned short iport_old;
struct in_addr address;
unsigned int timestamp;
proto = proto_atoi(protocol);
if(inet_aton(iaddr, &address) <= 0) {
syslog(LOG_ERR, "inet_aton(%s) FAILED", iaddr);
return -1;
}
if(!check_upnp_rule_against_permissions(upnppermlist, num_upnpperm,
eport, address, iport, desc)) {
syslog(LOG_INFO, "redirection permission check failed for "
"%hu->%s:%hu %s %s", eport, iaddr, iport, protocol, desc);
return -3;
}
if (desc == NULL)
desc = ""; /* assume empty description */
/* IGDv1 (WANIPConnection:1 Service Template Version 1.01 / Nov 12, 2001)
* - 2.2.20.PortMappingDescription :
* Overwriting Previous / Existing Port Mappings:
* If the RemoteHost, ExternalPort, PortMappingProtocol and InternalClient
* are exactly the same as an existing mapping, the existing mapping values
* for InternalPort, PortMappingDescription, PortMappingEnabled and
* PortMappingLeaseDuration are overwritten.
* Rejecting a New Port Mapping:
* In cases where the RemoteHost, ExternalPort and PortMappingProtocol
* are the same as an existing mapping, but the InternalClient is
* different, the action is rejected with an appropriate error.
* Add or Reject New Port Mapping behavior based on vendor implementation:
* In cases where the ExternalPort, PortMappingProtocol and InternalClient
* are the same, but RemoteHost is different, the vendor can choose to
* support both mappings simultaneously, or reject the second mapping
* with an appropriate error.
*
* - 2.4.16.AddPortMapping
* This action creates a new port mapping or overwrites an existing
* mapping with the same internal client. If the ExternalPort and
* PortMappingProtocol pair is already mapped to another internal client,
* an error is returned.
*
* IGDv2 (WANIPConnection:2 Service Standardized DCP (SDCP) Sep 10, 2010)
* Protocol ExternalPort RemoteHost InternalClient Result
* = = ≠ ≠ Failure
* = = ≠ = Failure or success
* (vendor specific)
* = = = ≠ Failure
* = = = = Success (overwrite)
*/
rhost_old[0] = '\0';
r = get_redirect_rule(ext_if_name, eport, proto,
iaddr_old, sizeof(iaddr_old), &iport_old, 0, 0,
rhost_old, sizeof(rhost_old),
&timestamp, 0, 0);
if(r == 0) {
if(strcmp(iaddr, iaddr_old)==0 &&
((rhost == NULL && rhost_old[0]=='\0') ||
(rhost && (strcmp(rhost, "*") == 0) && rhost_old[0]=='\0') ||
(rhost && (strcmp(rhost, rhost_old) == 0)))) {
syslog(LOG_INFO, "updating existing port mapping %hu %s (rhost '%s') => %s:%hu",
eport, protocol, rhost_old, iaddr_old, iport_old);
timestamp = (leaseduration > 0) ? upnp_time() + leaseduration : 0;
if(iport != iport_old) {
r = update_portmapping(ext_if_name, eport, proto, iport, desc, timestamp);
} else {
r = update_portmapping_desc_timestamp(ext_if_name, eport, proto, desc, timestamp);
}
#ifdef ENABLE_LEASEFILE
if(r == 0) {
lease_file_remove(eport, proto);
lease_file_add(eport, iaddr, iport, proto, desc, timestamp);
}
#endif /* ENABLE_LEASEFILE */
return r;
} else {
syslog(LOG_INFO, "port %hu %s (rhost '%s') already redirected to %s:%hu",
eport, protocol, rhost_old, iaddr_old, iport_old);
return -2;
}
#ifdef CHECK_PORTINUSE
} else if (port_in_use(ext_if_name, eport, proto, iaddr, iport) > 0) {
syslog(LOG_INFO, "port %hu protocol %s already in use",
eport, protocol);
return -4;
#endif /* CHECK_PORTINUSE */
} else {
timestamp = (leaseduration > 0) ? upnp_time() + leaseduration : 0;
syslog(LOG_INFO, "redirecting port %hu to %s:%hu protocol %s for: %s",
eport, iaddr, iport, protocol, desc);
return upnp_redirect_internal(rhost, eport, iaddr, iport, proto,
desc, timestamp);
}
}
int
upnp_redirect_internal(const char * rhost, unsigned short eport,
const char * iaddr, unsigned short iport,
int proto, const char * desc,
unsigned int timestamp)
{
/*syslog(LOG_INFO, "redirecting port %hu to %s:%hu protocol %s for: %s",
eport, iaddr, iport, protocol, desc); */
if(disable_port_forwarding)
return -1;
if(add_redirect_rule2(ext_if_name, rhost, eport, iaddr, iport, proto,
desc, timestamp) < 0) {
return -1;
}
#ifdef ENABLE_LEASEFILE
lease_file_add( eport, iaddr, iport, proto, desc, timestamp);
#endif
/* syslog(LOG_INFO, "creating pass rule to %s:%hu protocol %s for: %s",
iaddr, iport, protocol, desc);*/
if(add_filter_rule2(ext_if_name, rhost, iaddr, eport, iport, proto, desc) < 0) {
/* clean up the redirect rule */
#if !defined(__linux__)
delete_redirect_rule(ext_if_name, eport, proto);
#endif
return -1;
}
if(timestamp > 0) {
if(!nextruletoclean_timestamp || (timestamp < nextruletoclean_timestamp))
nextruletoclean_timestamp = timestamp;
}
#ifdef ENABLE_EVENTS
/* the number of port mappings changed, we must
* inform the subscribers */
upnp_event_var_change_notify(EWanIPC);
#endif
return 0;
}
/* Firewall independent code which call the FW dependent code. */
int
upnp_get_redirection_infos(unsigned short eport, const char * protocol,
unsigned short * iport,
char * iaddr, int iaddrlen,
char * desc, int desclen,
char * rhost, int rhostlen,
unsigned int * leaseduration)
{
int r;
unsigned int timestamp;
time_t current_time;
if(desc && (desclen > 0))
desc[0] = '\0';
if(rhost && (rhostlen > 0))
rhost[0] = '\0';
r = get_redirect_rule(ext_if_name, eport, proto_atoi(protocol),
iaddr, iaddrlen, iport, desc, desclen,
rhost, rhostlen, &timestamp,
0, 0);
if(r == 0 &&
timestamp > 0 &&
timestamp > (unsigned int)(current_time = upnp_time())) {
*leaseduration = timestamp - current_time;
} else {
*leaseduration = 0;
}
return r;
}
int
upnp_get_redirection_infos_by_index(int index,
unsigned short * eport, char * protocol,
unsigned short * iport,
char * iaddr, int iaddrlen,
char * desc, int desclen,
char * rhost, int rhostlen,
unsigned int * leaseduration)
{
/*char ifname[IFNAMSIZ];*/
int proto = 0;
unsigned int timestamp;
time_t current_time;
if(desc && (desclen > 0))
desc[0] = '\0';
if(rhost && (rhostlen > 0))
rhost[0] = '\0';
if(get_redirect_rule_by_index(index, 0/*ifname*/, eport, iaddr, iaddrlen,
iport, &proto, desc, desclen,
rhost, rhostlen, &timestamp,
0, 0) < 0)
return -1;
else
{
current_time = upnp_time();
*leaseduration = (timestamp > (unsigned int)current_time)
? (timestamp - current_time)
: 0;
if(proto == IPPROTO_TCP)
memcpy(protocol, "TCP", 4);
#ifdef IPPROTO_UDPLITE
else if(proto == IPPROTO_UDPLITE)
memcpy(protocol, "UDPLITE", 8);
#endif /* IPPROTO_UDPLITE */
else
memcpy(protocol, "UDP", 4);
return 0;
}
}
/* called from natpmp.c too */
int
_upnp_delete_redir(unsigned short eport, int proto)
{
int r;
#if defined(__linux__)
r = delete_redirect_and_filter_rules(eport, proto);
#elif defined(USE_PF)
r = delete_redirect_and_filter_rules(ext_if_name, eport, proto);
#else
r = delete_redirect_rule(ext_if_name, eport, proto);
delete_filter_rule(ext_if_name, eport, proto);
#endif
#ifdef ENABLE_LEASEFILE
lease_file_remove( eport, proto);
#endif
#ifdef ENABLE_EVENTS
upnp_event_var_change_notify(EWanIPC);
#endif
return r;
}
int
upnp_delete_redirection(unsigned short eport, const char * protocol)
{
syslog(LOG_INFO, "removing redirect rule port %hu %s", eport, protocol);
return _upnp_delete_redir(eport, proto_atoi(protocol));
}
/* upnp_get_portmapping_number_of_entries() */
int
upnp_get_portmapping_number_of_entries()
{
#if defined(USE_PF) || defined(USE_NFTABLES)
return get_redirect_rule_count(ext_if_name);
#else
int n = 0, r = 0;
unsigned short eport, iport;
char protocol[8], iaddr[32], desc[64], rhost[32];
unsigned int leaseduration;
do {
protocol[0] = '\0'; iaddr[0] = '\0'; desc[0] = '\0';
r = upnp_get_redirection_infos_by_index(n, &eport, protocol, &iport,
iaddr, sizeof(iaddr),
desc, sizeof(desc),
rhost, sizeof(rhost),
&leaseduration);
n++;
} while(r==0);
return (n-1);
#endif
}
/* functions used to remove unused rules
* As a side effect, delete expired rules (based on LeaseDuration) */
struct rule_state *
get_upnp_rules_state_list(int max_rules_number_target)
{
/*char ifname[IFNAMSIZ];*/
int proto;
unsigned short iport;
unsigned int timestamp;
struct rule_state * tmp;
struct rule_state * list = 0;
struct rule_state * * p;
int i = 0;
time_t current_time;
/*ifname[0] = '\0';*/
tmp = malloc(sizeof(struct rule_state));
if(!tmp)
return 0;
current_time = upnp_time();
nextruletoclean_timestamp = 0;
while(get_redirect_rule_by_index(i, /*ifname*/0, &tmp->eport, 0, 0,
&iport, &proto, 0, 0, 0,0, &timestamp,
&tmp->packets, &tmp->bytes) >= 0)
{
tmp->to_remove = 0;
if(timestamp > 0) {
/* need to remove this port mapping ? */
if(timestamp <= (unsigned int)current_time)
tmp->to_remove = 1;
else if((nextruletoclean_timestamp <= (unsigned int)current_time)
|| (timestamp < nextruletoclean_timestamp))
nextruletoclean_timestamp = timestamp;
}
tmp->proto = (short)proto;
/* add tmp to list */
tmp->next = list;
list = tmp;
/* prepare next iteration */
i++;
tmp = malloc(sizeof(struct rule_state));
if(!tmp)
break;
}
#ifdef PCP_PEER
i=0;
while(get_peer_rule_by_index(i, /*ifname*/0, &tmp->eport, 0, 0,
&iport, &proto, 0, 0, 0,0,0, &timestamp,
&tmp->packets, &tmp->bytes) >= 0)
{
tmp->to_remove = 0;
if(timestamp > 0) {
/* need to remove this port mapping ? */
if(timestamp <= (unsigned int)current_time)
tmp->to_remove = 1;
else if((nextruletoclean_timestamp <= (unsigned int)current_time)
|| (timestamp < nextruletoclean_timestamp))
nextruletoclean_timestamp = timestamp;
}
tmp->proto = (short)proto;
/* add tmp to list */
tmp->next = list;
list = tmp;
/* prepare next iteration */
i++;
tmp = malloc(sizeof(struct rule_state));
if(!tmp)
break;
}
#endif
free(tmp);
/* remove the redirections that need to be removed */
for(p = &list, tmp = list; tmp; tmp = *p)
{
if(tmp->to_remove)
{
syslog(LOG_NOTICE, "remove port mapping %hu %s because it has expired",
tmp->eport, proto_itoa(tmp->proto));
_upnp_delete_redir(tmp->eport, tmp->proto);
*p = tmp->next;
free(tmp);
i--;
} else {
p = &(tmp->next);
}
}
/* return empty list if not enough redirections */
if(i<=max_rules_number_target)
while(list)
{
tmp = list;
list = tmp->next;
free(tmp);
}
/* return list */
return list;
}
void
remove_unused_rules(struct rule_state * list)
{
char ifname[IFNAMSIZ];
unsigned short iport;
struct rule_state * tmp;
u_int64_t packets;
u_int64_t bytes;
unsigned int timestamp;
int n = 0;
while(list)
{
/* remove the rule if no traffic has used it */
if(get_redirect_rule(ifname, list->eport, list->proto,
0, 0, &iport, 0, 0, 0, 0, &timestamp,
&packets, &bytes) >= 0)
{
if(packets == list->packets && bytes == list->bytes)
{
syslog(LOG_DEBUG, "removing unused mapping %hu %s : still "
"%" PRIu64 "packets %" PRIu64 "bytes",
list->eport, proto_itoa(list->proto),
packets, bytes);
_upnp_delete_redir(list->eport, list->proto);
n++;
}
}
tmp = list;
list = tmp->next;
free(tmp);
}
if(n>0)
syslog(LOG_NOTICE, "removed %d unused rules", n);
}
/* upnp_get_portmappings_in_range()
* return a list of all "external" ports for which a port
* mapping exists */
unsigned short *
upnp_get_portmappings_in_range(unsigned short startport,
unsigned short endport,
const char * protocol,
unsigned int * number)
{
int proto;
proto = proto_atoi(protocol);
if(!number)
return NULL;
return get_portmappings_in_range(startport, endport, proto, number);
}
/* stuff for miniupnpdctl */
#ifdef USE_MINIUPNPDCTL
void
write_ruleset_details(int s)
{
int proto = 0;
unsigned short eport, iport;
char desc[64];
char iaddr[32];
char rhost[32];
unsigned int timestamp;
u_int64_t packets;
u_int64_t bytes;
int i = 0;
char buffer[256];
int n;
write(s, "Ruleset :\n", 10);
while(get_redirect_rule_by_index(i, 0/*ifname*/, &eport, iaddr, sizeof(iaddr),
&iport, &proto, desc, sizeof(desc),
rhost, sizeof(rhost),
&timestamp,
&packets, &bytes) >= 0)
{
n = snprintf(buffer, sizeof(buffer),
"%2d %s %s:%hu->%s:%hu "
"'%s' %u %" PRIu64 " %" PRIu64 "\n",
/*"'%s' %llu %llu\n",*/
i, proto_itoa(proto), rhost,
eport, iaddr, iport, desc, timestamp, packets, bytes);
write(s, buffer, n);
i++;
}
}
#endif