StunUsageIceReturn
stun_usage_ice_conncheck_create_reply (StunAgent *agent, StunMessage *req,
StunMessage *msg, uint8_t *buf, size_t *plen,
const struct sockaddr *src, socklen_t srclen,
bool *control, uint64_t tie,
StunUsageIceCompatibility compatibility)
{
const char *username = NULL;
uint16_t username_len;
size_t len = *plen;
uint64_t q;
StunMessageReturn val = STUN_MESSAGE_RETURN_SUCCESS;
StunUsageIceReturn ret = STUN_USAGE_ICE_RETURN_SUCCESS;
#define err( code ) \
stun_bind_error (agent, msg, buf, &len, req, code); \
*plen = len
*plen = 0;
stun_debug ("STUN Reply (buffer size = %u)...\n", (unsigned)len);
if (stun_message_get_class (req) != STUN_REQUEST)
{
stun_debug (" Unhandled non-request (class %u) message.\n",
stun_message_get_class (req));
return STUN_USAGE_ICE_RETURN_INVALID_REQUEST;
}
if (stun_message_get_method (req) != STUN_BINDING)
{
stun_debug (" Bad request (method %u) message.\n",
stun_message_get_method (req));
err (STUN_ERROR_BAD_REQUEST);
return STUN_USAGE_ICE_RETURN_INVALID_METHOD;
}
/* Role conflict handling */
assert (control != NULL);
if (stun_message_find64 (req, *control ? STUN_ATTRIBUTE_ICE_CONTROLLING
: STUN_ATTRIBUTE_ICE_CONTROLLED, &q) == STUN_MESSAGE_RETURN_SUCCESS)
{
stun_debug ("STUN Role Conflict detected:\n");
if (tie < q)
{
stun_debug (" switching role from \"controll%s\" to \"controll%s\"\n",
*control ? "ing" : "ed", *control ? "ed" : "ing");
*control = !*control;
ret = STUN_USAGE_ICE_RETURN_ROLE_CONFLICT;
}
else
{
stun_debug (" staying \"controll%s\" (sending error)\n",
*control ? "ing" : "ed");
err (STUN_ERROR_ROLE_CONFLICT);
return STUN_USAGE_ICE_RETURN_SUCCESS;
}
} else {
stun_debug ("STUN Role not specified by peer!\n");
}
if (stun_agent_init_response (agent, msg, buf, len, req) == FALSE) {
stun_debug ("Unable to create response\n");
goto failure;
}
if (compatibility == STUN_USAGE_ICE_COMPATIBILITY_MSN) {
StunTransactionId transid;
uint32_t magic_cookie;
stun_message_id (msg, transid);
magic_cookie = *((uint32_t *) transid);
val = stun_message_append_xor_addr_full (msg, STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS,
src, srclen, htonl (magic_cookie));
} else if (stun_message_has_cookie (msg)) {
val = stun_message_append_xor_addr (msg, STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS,
src, srclen);
} else {
val = stun_message_append_addr (msg, STUN_ATTRIBUTE_MAPPED_ADDRESS,
src, srclen);
}
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug (" Mapped address problem: %d\n", val);
goto failure;
}
username = (const char *)stun_message_find (req,
STUN_ATTRIBUTE_USERNAME, &username_len);
if (username) {
val = stun_message_append_bytes (msg, STUN_ATTRIBUTE_USERNAME,
username, username_len);
}
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug ("Error appending username: %d\n", val);
goto failure;
}
/* the stun agent will automatically use the password of the request */
len = stun_agent_finish_message (agent, msg, NULL, 0);
if (len == 0)
goto failure;
*plen = len;
stun_debug (" All done (response size: %u)\n", (unsigned)len);
return ret;
failure:
assert (*plen == 0);
stun_debug (" Fatal error formatting Response: %d\n", val);
switch (val)
{
case STUN_MESSAGE_RETURN_NOT_ENOUGH_SPACE:
return STUN_USAGE_ICE_RETURN_MEMORY_ERROR;
case STUN_MESSAGE_RETURN_INVALID:
case STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS:
return STUN_USAGE_ICE_RETURN_INVALID_ADDRESS;
default:
return STUN_USAGE_ICE_RETURN_ERROR;
}
}
StunUsageIceReturn
stun_usage_ice_conncheck_create_reply (StunAgent *agent, StunMessage *req,
StunMessage *msg, uint8_t *buf, size_t *plen,
const struct sockaddr_storage *src, socklen_t srclen,
bool *control, uint64_t tie,
StunUsageIceCompatibility compatibility)
{
const char *username = NULL;
uint16_t username_len;
size_t len = *plen;
uint64_t q;
StunMessageReturn val = STUN_MESSAGE_RETURN_SUCCESS;
StunUsageIceReturn ret = STUN_USAGE_ICE_RETURN_SUCCESS;
#define err( code ) \
stun_bind_error (agent, msg, buf, &len, req, code); \
*plen = len
*plen = 0;
stun_debug ("STUN Reply (buffer size = %u)...", (unsigned)len);
if (stun_message_get_class (req) != STUN_REQUEST)
{
stun_debug (" Unhandled non-request (class %u) message.",
stun_message_get_class (req));
return STUN_USAGE_ICE_RETURN_INVALID_REQUEST;
}
if (stun_message_get_method (req) != STUN_BINDING)
{
stun_debug (" Bad request (method %u) message.",
stun_message_get_method (req));
err (STUN_ERROR_BAD_REQUEST);
return STUN_USAGE_ICE_RETURN_INVALID_METHOD;
}
/* Role conflict handling */
assert (control != NULL);
if (stun_message_find64 (req, *control ? STUN_ATTRIBUTE_ICE_CONTROLLING
: STUN_ATTRIBUTE_ICE_CONTROLLED, &q) == STUN_MESSAGE_RETURN_SUCCESS)
{
/* we have the ice-controlling/controlled attribute,
* and there's a role conflict
*/
stun_debug ("STUN Role Conflict detected:");
/* According to ICE RFC 5245, section 7.2.1.1, we consider the four
* possible cases when a role conflict is detected: two cases are
* resolved by switching role locally, and the two other cases are
* handled by responding with a STUN error.
*/
if ((tie < q && *control) || (tie >= q && !*control))
{
stun_debug (" switching role from \"controll%s\" to \"controll%s\"",
*control ? "ing" : "ed", *control ? "ed" : "ing");
*control = !*control;
ret = STUN_USAGE_ICE_RETURN_ROLE_CONFLICT;
}
else
{
stun_debug (" staying \"controll%s\" (sending error)",
*control ? "ing" : "ed");
err (STUN_ERROR_ROLE_CONFLICT);
return STUN_USAGE_ICE_RETURN_ROLE_CONFLICT;
}
} else {
if (stun_message_find64 (req, *control ? STUN_ATTRIBUTE_ICE_CONTROLLED
: STUN_ATTRIBUTE_ICE_CONTROLLING, &q) != STUN_MESSAGE_RETURN_SUCCESS)
{
/* we don't have the expected ice-controlling/controlled
* attribute
*/
if (compatibility == STUN_USAGE_ICE_COMPATIBILITY_RFC5245 ||
compatibility == STUN_USAGE_ICE_COMPATIBILITY_MSICE2)
{
stun_debug ("STUN Role not specified by peer!");
}
}
}
if (stun_agent_init_response (agent, msg, buf, len, req) == FALSE) {
stun_debug ("Unable to create response");
goto failure;
}
if (compatibility == STUN_USAGE_ICE_COMPATIBILITY_MSN) {
union {
StunTransactionId transid;
uint32_t magic_cookie;
} conv;
stun_message_id (msg, conv.transid);
val = stun_message_append_xor_addr_full (msg, STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS,
src, srclen, htonl (conv.magic_cookie));
} else if (stun_message_has_cookie (msg) &&
compatibility != STUN_USAGE_ICE_COMPATIBILITY_GOOGLE) {
val = stun_message_append_xor_addr (msg, STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS,
src, srclen);
} else {
val = stun_message_append_addr (msg, STUN_ATTRIBUTE_MAPPED_ADDRESS,
(struct sockaddr *) src, srclen);
}
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug (" Mapped address problem: %d", val);
goto failure;
}
username = (const char *)stun_message_find (req,
STUN_ATTRIBUTE_USERNAME, &username_len);
if (username) {
val = stun_message_append_bytes (msg, STUN_ATTRIBUTE_USERNAME,
username, username_len);
}
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug ("Error appending username: %d", val);
goto failure;
}
if (compatibility == STUN_USAGE_ICE_COMPATIBILITY_MSICE2) {
val = stun_message_append32 (msg,
STUN_ATTRIBUTE_MS_IMPLEMENTATION_VERSION, 2);
if (val != STUN_MESSAGE_RETURN_SUCCESS) {
stun_debug ("Error appending implementation version: %d", val);
goto failure;
}
}
/* the stun agent will automatically use the password of the request */
len = stun_agent_finish_message (agent, msg, NULL, 0);
if (len == 0)
goto failure;
*plen = len;
stun_debug (" All done (response size: %u)", (unsigned)len);
return ret;
failure:
assert (*plen == 0);
stun_debug (" Fatal error formatting Response: %d", val);
switch (val)
{
case STUN_MESSAGE_RETURN_NOT_ENOUGH_SPACE:
return STUN_USAGE_ICE_RETURN_MEMORY_ERROR;
case STUN_MESSAGE_RETURN_INVALID:
case STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS:
return STUN_USAGE_ICE_RETURN_INVALID_ADDRESS;
case STUN_MESSAGE_RETURN_SUCCESS:
assert (0); /* shouldn’t be reached */
case STUN_MESSAGE_RETURN_NOT_FOUND:
default:
return STUN_USAGE_ICE_RETURN_ERROR;
}
}
