udpstunner: don't open code header fields, reference and follow (old) RFC

This commit is contained in:
sehraf 2020-02-05 19:46:29 +01:00
parent 4095d82a67
commit e91d877af2
No known key found for this signature in database
GPG Key ID: DF09F6EAE356B2C6
2 changed files with 37 additions and 23 deletions

View File

@ -47,6 +47,12 @@ const uint32_t TOU_STUN_MAX_RECV_RATE = 25; /* every 25 seconds */
const int32_t TOU_STUN_DEFAULT_TARGET_RATE = 15; /* 20 secs is minimum to keep a NAT UDP port open */ const int32_t TOU_STUN_DEFAULT_TARGET_RATE = 15; /* 20 secs is minimum to keep a NAT UDP port open */
const double TOU_SUCCESS_LPF_FACTOR = 0.90; const double TOU_SUCCESS_LPF_FACTOR = 0.90;
/*
* based on RFC 3489
*/
const uint16_t STUN_BINDING_REQUEST = 0x0001;
const uint16_t STUN_BINDING_RESPONSE = 0x0101;
#define EXCLUSIVE_MODE_TIMEOUT 300 #define EXCLUSIVE_MODE_TIMEOUT 300
UdpStunner::UdpStunner(UdpPublisher *pub) UdpStunner::UdpStunner(UdpPublisher *pub)
@ -187,7 +193,6 @@ int UdpStunner::releaseExclusiveMode(std::string holder, bool forceStun)
return 0; return 0;
} }
rstime_t now = time(NULL);
mExclusiveMode = false; mExclusiveMode = false;
if (forceStun) if (forceStun)
{ {
@ -217,6 +222,7 @@ int UdpStunner::releaseExclusiveMode(std::string holder, bool forceStun)
} }
#ifdef DEBUG_UDP_STUNNER_FILTER #ifdef DEBUG_UDP_STUNNER_FILTER
rstime_t now = time(NULL);
std::cerr << "UdpStunner::cancelExclusiveMode() Canceled. Was in ExclusiveMode for: " << now - mExclusiveModeTS; std::cerr << "UdpStunner::cancelExclusiveMode() Canceled. Was in ExclusiveMode for: " << now - mExclusiveModeTS;
std::cerr << " secs"; std::cerr << " secs";
std::cerr << std::endl; std::cerr << std::endl;
@ -326,7 +332,7 @@ bool UdpStunner::locked_handleStunPkt(void *data, int size, struct sockaddr_in &
#endif #endif
/* generate a response */ /* generate a response */
int len; int len;
void *pkt = UdpStun_generate_stun_reply(&from, &len); void *pkt = UdpStun_generate_stun_reply(&from, &len, data);
if (!pkt) if (!pkt)
return false; return false;
@ -485,7 +491,7 @@ bool UdpStun_response(void *stun_pkt, int size, struct sockaddr_in &addr)
return false; return false;
} }
if (htons(((uint16_t *) stun_pkt)[0]) != 0x0101) if (htons(((uint16_t *) stun_pkt)[0]) != STUN_BINDING_RESPONSE)
{ {
/* not a response */ /* not a response */
return false; return false;
@ -517,19 +523,27 @@ bool UdpStun_generate_stun_pkt(void *stun_pkt, int *len)
} }
/* just the header */ /* just the header */
((uint16_t *) stun_pkt)[0] = (uint16_t) htons(0x0001); ((uint16_t *) stun_pkt)[0] = (uint16_t) htons(STUN_BINDING_REQUEST);
((uint16_t *) stun_pkt)[1] = (uint16_t) htons(20); /* only header */ ((uint16_t *) stun_pkt)[1] = (uint16_t) htons(20); /* only header */
/* transaction id - should be random */ /* RFC 3489
((uint32_t *) stun_pkt)[1] = (uint32_t) htonl(0x0020); * The transaction ID is used to correlate requests and responses.
((uint32_t *) stun_pkt)[2] = (uint32_t) htonl(0x0121); *
((uint32_t *) stun_pkt)[3] = (uint32_t) htonl(0x0111); * RFC 5389 introduces a mmgic cokie at the location where preciously the transaction ID was located:
((uint32_t *) stun_pkt)[4] = (uint32_t) htonl(0x1010); * In RFC 3489 [RFC3489], this field was part of
* the transaction ID; placing the magic cookie in this location allows
* a server to detect if the client will understand certain attributes
* that were added in this revised specification.
*/
((uint32_t *) stun_pkt)[1] = htonl(RsRandom::random_u32());
((uint32_t *) stun_pkt)[2] = htonl(RsRandom::random_u32());
((uint32_t *) stun_pkt)[3] = htonl(RsRandom::random_u32());
((uint32_t *) stun_pkt)[4] = htonl(RsRandom::random_u32());
*len = 20; *len = 20;
return true; return true;
} }
void *UdpStun_generate_stun_reply(struct sockaddr_in *stun_addr, int *len) void *UdpStun_generate_stun_reply(struct sockaddr_in *stun_addr, int *len, const void *data)
{ {
/* just the header */ /* just the header */
void *stun_pkt = rs_malloc(28); void *stun_pkt = rs_malloc(28);
@ -537,13 +551,13 @@ void *UdpStun_generate_stun_reply(struct sockaddr_in *stun_addr, int *len)
if(!stun_pkt) if(!stun_pkt)
return NULL ; return NULL ;
((uint16_t *) stun_pkt)[0] = (uint16_t) htons(0x0101); ((uint16_t *) stun_pkt)[0] = (uint16_t) htons(STUN_BINDING_RESPONSE);
((uint16_t *) stun_pkt)[1] = (uint16_t) htons(28); /* only header + 8 byte addr */ ((uint16_t *) stun_pkt)[1] = (uint16_t) htons(28); /* only header + 8 byte addr */
/* transaction id - should be random */ /* RFC 3489
((uint32_t *) stun_pkt)[1] = (uint32_t) htonl(0x0f20); * The Binding Response MUST contain the same transaction ID contained in the Binding Request.
((uint32_t *) stun_pkt)[2] = (uint32_t) htonl(0x0f21); */
((uint32_t *) stun_pkt)[3] = (uint32_t) htonl(0x0f11); memcpy(&((uint32_t *) stun_pkt)[1], &((uint32_t *) data)[1], 4 * sizeof (uint32_t));
((uint32_t *) stun_pkt)[4] = (uint32_t) htonl(0x1010);
/* now add address /* now add address
* 0 1 2 3 * 0 1 2 3
* <INET> <port> * <INET> <port>
@ -586,20 +600,20 @@ bool UdpStun_isStunPacket(void *data, int size)
return false; return false;
} }
if ((size == 20) && (0x0001 == ntohs(((uint16_t *) data)[0]))) if ((size == 20) && (STUN_BINDING_REQUEST == ntohs(((uint16_t *) data)[0])))
{ {
#ifdef DEBUG_UDP_STUNNER_FILTER #ifdef DEBUG_UDP_STUNNER_FILTER
std::cerr << "UdpStunner::isStunPacket() (size=20 & data[0]=0x0001) -> true"; std::cerr << "UdpStunner::isStunPacket() (size=20 & data[0]=STUN_BINDING_REQUEST) -> true";
std::cerr << std::endl; std::cerr << std::endl;
#endif #endif
/* request */ /* request */
return true; return true;
} }
if ((size == 28) && (0x0101 == ntohs(((uint16_t *) data)[0]))) if ((size == 28) && (STUN_BINDING_RESPONSE == ntohs(((uint16_t *) data)[0])))
{ {
#ifdef DEBUG_UDP_STUNNER_FILTER #ifdef DEBUG_UDP_STUNNER_FILTER
std::cerr << "UdpStunner::isStunPacket() (size=28 & data[0]=0x0101) -> true"; std::cerr << "UdpStunner::isStunPacket() (size=28 & data[0]=STUN_BINDING_RESPONSE) -> true";
std::cerr << std::endl; std::cerr << std::endl;
#endif #endif
/* response */ /* response */

View File

@ -170,7 +170,7 @@ bool locked_checkExternalAddress();
bool UdpStun_isStunPacket(void *data, int size); bool UdpStun_isStunPacket(void *data, int size);
bool UdpStun_response(void *stun_pkt, int size, struct sockaddr_in &addr); bool UdpStun_response(void *stun_pkt, int size, struct sockaddr_in &addr);
void *UdpStun_generate_stun_reply(struct sockaddr_in *stun_addr, int *len); void *UdpStun_generate_stun_reply(struct sockaddr_in *stun_addr, int *len, const void* data);
bool UdpStun_generate_stun_pkt(void *stun_pkt, int *len); bool UdpStun_generate_stun_pkt(void *stun_pkt, int *len);
#endif #endif