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, ×tamp,
&packets, &bytes) >= 0)
{
if(packets == list->packets && bytes == list->bytes)
{
if(_upnp_delete_redir(list->eport, list->proto) >= 0)
n++;
}
}
tmp = list;
list = tmp->next;
free(tmp);
}
if(n>0)
syslog(LOG_NOTICE, "removed %d unused rules", n);
}
/* remove the next redirection that is expired
*/
int CleanExpiredNATPMP()
{
char desc[64];
unsigned timestamp;
unsigned short iport;
if(get_redirect_rule(ext_if_name, nextnatpmptoclean_eport,
nextnatpmptoclean_proto,
0, 0,
&iport, desc, sizeof(desc), ×tamp, 0, 0) < 0)
return ScanNATPMPforExpiration();
/* check desc - this is important since we keep expiration time as part
* of the desc.
* If the rule is renewed, timestamp and nextnatpmptoclean_timestamp
* can be different. In that case, the rule must not be removed ! */
if(sscanf(desc, "NAT-PMP %u", ×tamp) == 1) {
if(timestamp > nextnatpmptoclean_timestamp)
return ScanNATPMPforExpiration();
}
/* remove redirection then search for next one:) */
if(_upnp_delete_redir(nextnatpmptoclean_eport, nextnatpmptoclean_proto)<0)
return -1;
syslog(LOG_NOTICE, "Expired NAT-PMP mapping port %hu %s removed",
nextnatpmptoclean_eport,
nextnatpmptoclean_proto==IPPROTO_TCP?"TCP":"UDP");
return ScanNATPMPforExpiration();
}
/* upnp_redirect()
* calls OS/fw dependant 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
*/
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];
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) : %m", iaddr);
return -1;
}
if(!check_upnp_rule_against_permissions(upnppermlist, num_upnpperm,
eport, address, iport)) {
syslog(LOG_INFO, "redirection permission check failed for "
"%hu->%s:%hu %s", eport, iaddr, iport, protocol);
return -3;
}
r = get_redirect_rule(ext_if_name, eport, proto,
iaddr_old, sizeof(iaddr_old), &iport_old, 0, 0,
0, 0,
×tamp, 0, 0);
if(r == 0) {
/* if existing redirect rule matches redirect request return success
* xbox 360 does not keep track of the port it redirects and will
* redirect another port when receiving ConflictInMappingEntry */
if(strcmp(iaddr, iaddr_old)==0 && iport==iport_old) {
/* redirection allready exists */
syslog(LOG_INFO, "port %hu %s already redirected to %s:%hu, replacing", eport, (proto==IPPROTO_TCP)?"tcp":"udp", iaddr_old, iport_old);
/* remove and then add again */
if(_upnp_delete_redir(eport, proto) < 0) {
syslog(LOG_ERR, "failed to remove port mapping");
return 0;
}
} else {
syslog(LOG_INFO, "port %hu protocol %s already redirected to %s:%hu",
eport, protocol, 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 -2;
#endif /* CHECK_PORTINUSE */
}
timestamp = (leaseduration > 0) ? time(NULL) + 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);
}
/* 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 = time(NULL);
nextruletoclean_timestamp = 0;
while(get_redirect_rule_by_index(i, /*ifname*/0, &tmp->eport, 0, 0,
&iport, &proto, 0, 0, 0,0, ×tamp,
&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;
}
free(tmp);
/* remove the redirections that need to be removed */
for(p = &list, tmp = list; tmp; tmp = *p)
{
if(tmp->to_remove)
{
syslog(LOG_INFO, "remove port mapping %hu %s because it has expired",
tmp->eport, (tmp->proto==IPPROTO_TCP)?"TCP":"UDP");
_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;
}
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));
}
/** read the request from the socket, process it and then send the
* response back.
*/
void ProcessIncomingNATPMPPacket(int s)
{
unsigned char req[32]; /* request udp packet */
unsigned char resp[32]; /* response udp packet */
int resplen;
struct sockaddr_in senderaddr;
socklen_t senderaddrlen = sizeof(senderaddr);
int n;
char senderaddrstr[16];
n = recvfrom(s, req, sizeof(req), 0,
(struct sockaddr *)&senderaddr, &senderaddrlen);
if(n<0) {
/* EAGAIN, EWOULDBLOCK and EINTR : silently ignore (retry next time)
* other errors : log to LOG_ERR */
if(errno != EAGAIN &&
errno != EWOULDBLOCK &&
errno != EINTR) {
syslog(LOG_ERR, "recvfrom(natpmp): %m");
}
return;
}
if(!inet_ntop(AF_INET, &senderaddr.sin_addr,
senderaddrstr, sizeof(senderaddrstr))) {
syslog(LOG_ERR, "inet_ntop(natpmp): %m");
}
syslog(LOG_INFO, "NAT-PMP request received from %s:%hu %dbytes",
senderaddrstr, ntohs(senderaddr.sin_port), n);
if(n<2 || ((((req[1]-1)&~1)==0) && n<12)) {
syslog(LOG_WARNING, "discarding NAT-PMP request (too short) %dBytes",
n);
return;
}
if(req[1] & 128) {
/* discarding NAT-PMP responses silently */
return;
}
memset(resp, 0, sizeof(resp));
resplen = 8;
resp[1] = 128 + req[1]; /* response OPCODE is request OPCODE + 128 */
/* setting response TIME STAMP :
* time elapsed since its port mapping table was initialized on
* startup or reset for any other reason */
*((uint32_t *)(resp+4)) = htonl(time(NULL) - startup_time);
if(req[0] > 0) {
/* invalid version */
syslog(LOG_WARNING, "unsupported NAT-PMP version : %u",
(unsigned)req[0]);
resp[3] = 1; /* unsupported version */
} else switch(req[1]) {
case 0: /* Public address request */
syslog(LOG_INFO, "NAT-PMP public address request");
FillPublicAddressResponse(resp, senderaddr.sin_addr.s_addr);
resplen = 12;
break;
case 1: /* UDP port mapping request */
case 2: /* TCP port mapping request */
{
unsigned short iport; /* private port */
unsigned short eport; /* public port */
uint32_t lifetime; /* lifetime=0 => remove port mapping */
int r;
int proto;
char iaddr_old[16];
unsigned short iport_old;
unsigned int timestamp;
iport = ntohs(*((uint16_t *)(req+4)));
eport = ntohs(*((uint16_t *)(req+6)));
lifetime = ntohl(*((uint32_t *)(req+8)));
proto = (req[1]==1)?IPPROTO_UDP:IPPROTO_TCP;
syslog(LOG_INFO, "NAT-PMP port mapping request : "
"%hu->%s:%hu %s lifetime=%us",
eport, senderaddrstr, iport,
(req[1]==1)?"udp":"tcp", lifetime);
if(eport==0)
eport = iport;
/* TODO: accept port mapping if iport ok but eport not ok
* (and set eport correctly) */
if(lifetime == 0) {
/* remove the mapping */
if(iport == 0) {
/* remove all the mappings for this client */
int index = 0;
unsigned short eport2, iport2;
char iaddr2[16];
int proto2;
char desc[64];
while(get_redirect_rule_by_index(index, 0,
&eport2, iaddr2, sizeof(iaddr2),
&iport2, &proto2,
desc, sizeof(desc),
0, 0, ×tamp, 0, 0) >= 0) {
syslog(LOG_DEBUG, "%d %d %hu->'%s':%hu '%s'",
index, proto2, eport2, iaddr2, iport2, desc);
if(0 == strcmp(iaddr2, senderaddrstr)
&& 0 == memcmp(desc, "NAT-PMP", 7)) {
r = _upnp_delete_redir(eport2, proto2);
/* TODO : check return value */
if(r<0) {
syslog(LOG_ERR, "failed to remove port mapping");
index++;
} else {
syslog(LOG_INFO, "NAT-PMP %s port %hu mapping removed",
proto2==IPPROTO_TCP?"TCP":"UDP", eport2);
}
} else {
index++;
}
}
} else {
/* To improve the interworking between nat-pmp and
* UPnP, we should check that we remove only NAT-PMP
* mappings */
r = _upnp_delete_redir(eport, proto);
/*syslog(LOG_DEBUG, "%hu %d r=%d", eport, proto, r);*/
if(r<0) {
//syslog(LOG_ERR, "Failed to remove NAT-PMP mapping eport %hu, protocol %s", eport, (proto==IPPROTO_TCP)?"TCP":"UDP");
resp[3] = 2; /* Not Authorized/Refused */
}
}
eport = 0; /* to indicate correct removing of port mapping */
} else if(iport==0
|| !check_upnp_rule_against_permissions(upnppermlist, num_upnpperm, eport, senderaddr.sin_addr, iport)) {
resp[3] = 2; /* Not Authorized/Refused */
} else do {
r = get_redirect_rule(ext_if_name, eport, proto,
iaddr_old, sizeof(iaddr_old),
&iport_old, 0, 0, 0, 0,
×tamp, 0, 0);
if(r==0) {
if(strcmp(senderaddrstr, iaddr_old)==0
&& iport==iport_old) {
/* redirection allready existing */
syslog(LOG_INFO, "port %hu %s already redirected to %s:%hu, replacing",
eport, (proto==IPPROTO_TCP)?"tcp":"udp", iaddr_old, iport_old);
/* remove and then add again */
if(_upnp_delete_redir(eport, proto) < 0) {
syslog(LOG_ERR, "failed to remove port mapping");
break;
}
} else {
eport++;
continue;
}
}
{ /* do the redirection */
char desc[64];
#if 0
timestamp = (unsigned)(time(NULL) - startup_time)
+ lifetime;
snprintf(desc, sizeof(desc), "NAT-PMP %u", timestamp);
#else
timestamp = time(NULL) + lifetime;
snprintf(desc, sizeof(desc), "NAT-PMP %hu %s",
eport, (proto==IPPROTO_TCP)?"tcp":"udp");
#endif
/* TODO : check return code */
if(upnp_redirect_internal(NULL, eport, senderaddrstr,
iport, proto, desc,
timestamp) < 0) {
syslog(LOG_ERR, "Failed to add NAT-PMP %hu %s->%s:%hu '%s'",
eport, (proto==IPPROTO_TCP)?"tcp":"udp", senderaddrstr, iport, desc);
resp[3] = 3; /* Failure */
#if 0
} else if( !nextnatpmptoclean_eport
|| timestamp < nextnatpmptoclean_timestamp) {
nextnatpmptoclean_timestamp = timestamp;
nextnatpmptoclean_eport = eport;
nextnatpmptoclean_proto = proto;
#endif
}
break;
}
} while(r==0);
*((uint16_t *)(resp+8)) = htons(iport); /* private port */
*((uint16_t *)(resp+10)) = htons(eport); /* public port */
*((uint32_t *)(resp+12)) = htonl(lifetime); /* Port Mapping lifetime */
}
resplen = 16;
break;
default:
resp[3] = 5; /* Unsupported OPCODE */
}
n = sendto(s, resp, resplen, 0,
(struct sockaddr *)&senderaddr, sizeof(senderaddr));
if(n<0) {
syslog(LOG_ERR, "sendto(natpmp): %m");
} else if(n<resplen) {
syslog(LOG_ERR, "sendto(natpmp): sent only %d bytes out of %d",
n, resplen);
}
}
int
upnp_delete_redirection(unsigned short eport, const char * protocol)
{
NP_UPNP_DEBUG("removing redirect rule port %hu %s\n", eport, protocol);
return _upnp_delete_redir(eport, proto_atoi(protocol));
}
/** read the request from the socket, process it and then send the
* response back.
*/
void ProcessIncomingNATPMPPacket(int s, unsigned char *msg_buff, int len,
struct sockaddr_in *senderaddr)
{
unsigned char *req=msg_buff; /* request udp packet */
unsigned char resp[32]; /* response udp packet */
int resplen;
int n = len;
char senderaddrstr[16];
if(!inet_ntop(AF_INET, &senderaddr->sin_addr,
senderaddrstr, sizeof(senderaddrstr))) {
syslog(LOG_ERR, "inet_ntop(natpmp): %m");
}
syslog(LOG_INFO, "NAT-PMP request received from %s:%hu %dbytes",
senderaddrstr, ntohs(senderaddr->sin_port), n);
if(n<2 || ((((req[1]-1)&~1)==0) && n<12)) {
syslog(LOG_WARNING, "discarding NAT-PMP request (too short) %dBytes",
n);
return;
}
if(req[1] & 128) {
/* discarding NAT-PMP responses silently */
return;
}
memset(resp, 0, sizeof(resp));
resplen = 8;
resp[1] = 128 + req[1]; /* response OPCODE is request OPCODE + 128 */
/* setting response TIME STAMP :
* time elapsed since its port mapping table was initialized on
* startup or reset for any other reason */
WRITENU32(resp+4, time(NULL) - startup_time);
if(req[0] > 0) {
/* invalid version */
syslog(LOG_WARNING, "unsupported NAT-PMP version : %u",
(unsigned)req[0]);
resp[3] = 1; /* unsupported version */
} else switch(req[1]) {
case 0: /* Public address request */
syslog(LOG_INFO, "NAT-PMP public address request");
FillPublicAddressResponse(resp, senderaddr->sin_addr.s_addr);
resplen = 12;
break;
case 1: /* UDP port mapping request */
case 2: /* TCP port mapping request */
{
unsigned short iport; /* private port */
unsigned short eport; /* public port */
uint32_t lifetime; /* lifetime=0 => remove port mapping */
int r;
int proto;
char iaddr_old[16];
unsigned short iport_old;
unsigned int timestamp;
iport = READNU16(req+4);
eport = READNU16(req+6);
lifetime = READNU32(req+8);
proto = (req[1]==1)?IPPROTO_UDP:IPPROTO_TCP;
syslog(LOG_INFO, "NAT-PMP port mapping request : "
"%hu->%s:%hu %s lifetime=%us",
eport, senderaddrstr, iport,
(req[1]==1)?"udp":"tcp", lifetime);
/* TODO: accept port mapping if iport ok but eport not ok
* (and set eport correctly) */
if(lifetime == 0) {
/* remove the mapping */
/* RFC6886 :
* A client MAY also send an explicit packet to request deletion of a
* mapping that is no longer needed. A client requests explicit
* deletion of a mapping by sending a message to the NAT gateway
* requesting the mapping, with the Requested Lifetime in Seconds set to
* zero. The Suggested External Port MUST be set to zero by the client
* on sending, and MUST be ignored by the gateway on reception. */
int index = 0;
unsigned short eport2, iport2;
char iaddr2[16];
int proto2;
char desc[64];
eport = 0; /* to indicate correct removing of port mapping */
while(get_redirect_rule_by_index(index, 0,
&eport2, iaddr2, sizeof(iaddr2),
&iport2, &proto2,
desc, sizeof(desc),
0, 0, ×tamp, 0, 0) >= 0) {
syslog(LOG_DEBUG, "%d %d %hu->'%s':%hu '%s'",
index, proto2, eport2, iaddr2, iport2, desc);
if(0 == strcmp(iaddr2, senderaddrstr)
&& 0 == memcmp(desc, "NAT-PMP", 7)) {
/* (iport == 0) => remove all the mappings for this client */
if((iport == 0) || ((iport == iport2) && (proto == proto2))) {
r = _upnp_delete_redir(eport2, proto2);
if(r < 0) {
syslog(LOG_ERR, "Failed to remove NAT-PMP mapping eport %hu, protocol %s",
eport2, (proto2==IPPROTO_TCP)?"TCP":"UDP");
resp[3] = 2; /* Not Authorized/Refused */
break;
} else {
syslog(LOG_INFO, "NAT-PMP %s port %hu mapping removed",
proto2==IPPROTO_TCP?"TCP":"UDP", eport2);
index--;
}
}
}
index++;
}
} else if(iport==0) {
resp[3] = 2; /* Not Authorized/Refused */
} else { /* iport > 0 && lifetime > 0 */
unsigned short eport_first = 0;
int any_eport_allowed = 0;
char desc[64];
if(eport==0) /* if no suggested external port, use same a internal port */
eport = iport;
while(resp[3] == 0) {
if(eport_first == 0) { /* first time in loop */
eport_first = eport;
} else if(eport == eport_first) { /* no eport available */
if(any_eport_allowed == 0) { /* all eports rejected by permissions */
syslog(LOG_ERR, "No allowed eport for NAT-PMP %hu %s->%s:%hu",
eport, (proto==IPPROTO_TCP)?"tcp":"udp", senderaddrstr, iport);
resp[3] = 2; /* Not Authorized/Refused */
} else { /* at least one eport allowed (but none available) */
syslog(LOG_ERR, "Failed to find available eport for NAT-PMP %hu %s->%s:%hu",
eport, (proto==IPPROTO_TCP)?"tcp":"udp", senderaddrstr, iport);
resp[3] = 4; /* Out of resources */
}
break;
}
if(!check_upnp_rule_against_permissions(upnppermlist, num_upnpperm, eport, senderaddr->sin_addr, iport)) {
eport++;
if(eport == 0) eport++; /* skip port zero */
continue;
}
any_eport_allowed = 1; /* at lease one eport is allowed */
#ifdef CHECK_PORTINUSE
if (port_in_use(ext_if_name, eport, proto, senderaddrstr, iport) > 0) {
syslog(LOG_INFO, "port %hu protocol %s already in use",
eport, (proto==IPPROTO_TCP)?"tcp":"udp");
eport++;
if(eport == 0) eport++; /* skip port zero */
continue;
}
#endif
r = get_redirect_rule(ext_if_name, eport, proto,
iaddr_old, sizeof(iaddr_old),
&iport_old, 0, 0, 0, 0,
×tamp, 0, 0);
if(r==0) {
if(strcmp(senderaddrstr, iaddr_old)==0
&& iport==iport_old) {
/* redirection already existing */
syslog(LOG_INFO, "port %hu %s already redirected to %s:%hu, replacing",
eport, (proto==IPPROTO_TCP)?"tcp":"udp", iaddr_old, iport_old);
/* remove and then add again */
if(_upnp_delete_redir(eport, proto) < 0) {
syslog(LOG_ERR, "failed to remove port mapping");
break;
}
} else {
eport++;
if(eport == 0) eport++; /* skip port zero */
continue;
}
}
/* do the redirection */
#if 0
timestamp = (unsigned)(time(NULL) - startup_time)
+ lifetime;
snprintf(desc, sizeof(desc), "NAT-PMP %u", timestamp);
#else
timestamp = time(NULL) + lifetime;
snprintf(desc, sizeof(desc), "NAT-PMP %hu %s",
eport, (proto==IPPROTO_TCP)?"tcp":"udp");
#endif
/* TODO : check return code */
if(upnp_redirect_internal(NULL, eport, senderaddrstr,
iport, proto, desc,
timestamp) < 0) {
syslog(LOG_ERR, "Failed to add NAT-PMP %hu %s->%s:%hu '%s'",
eport, (proto==IPPROTO_TCP)?"tcp":"udp", senderaddrstr, iport, desc);
resp[3] = 3; /* Failure */
}
break;
}
}
WRITENU16(resp+8, iport); /* private port */
WRITENU16(resp+10, eport); /* public port */
WRITENU32(resp+12, lifetime); /* Port Mapping lifetime */
}
resplen = 16;
break;
default:
resp[3] = 5; /* Unsupported OPCODE */
}
n = sendto_or_schedule(s, resp, resplen, 0,
(struct sockaddr *)senderaddr, sizeof(*senderaddr));
if(n<0) {
syslog(LOG_ERR, "sendto(natpmp): %m");
} else if(n<resplen) {
syslog(LOG_ERR, "sendto(natpmp): sent only %d bytes out of %d",
n, resplen);
}
}
