// Constructor for a source-independent multicast group
Groupsock::Groupsock(UsageEnvironment& env, struct in_addr const& groupAddr,
Port port, u_int8_t ttl)
: OutputSocket(env, port),
deleteIfNoMembers(False), isSlave(False),
fIncomingGroupEId(groupAddr, port.num(), ttl), fDests(NULL), fTTL(ttl) {
addDestination(groupAddr, port);
// printf("Groupsock: grpaddr %s\n", inet_ntoa(groupAddr)); //jay
if (!socketJoinGroup(env, socketNum(), groupAddr.s_addr)) {
if (DebugLevel >= 1) {
env << *this << ": failed to join group: "
<< env.getResultMsg() << "\n";
}
}
// Make sure we can get our source address:
if (ourIPAddress(env) == 0) {
if (DebugLevel >= 0) { // this is a fatal error
env << "Unable to determine our source address: "
<< env.getResultMsg() << "\n";
}
}
if (DebugLevel >= 2) env << *this << ": created\n";
}
// Constructor for a source-specific multicast group
Groupsock::Groupsock(UsageEnvironment& env, struct in_addr const& groupAddr,
struct in_addr const& sourceFilterAddr,
Port port)
: OutputSocket(env, port),
deleteIfNoMembers(False), isSlave(False),
fIncomingGroupEId(groupAddr, sourceFilterAddr, port.num()),
fDests(NULL), fTTL(255) {
addDestination(groupAddr, port);
// First try a SSM join. If that fails, try a regular join:
if (!socketJoinGroupSSM(env, socketNum(), groupAddr.s_addr,
sourceFilterAddr.s_addr)) {
if (DebugLevel >= 3) {
env << *this << ": SSM join failed: "
<< env.getResultMsg();
env << " - trying regular join instead\n";
}
if (!socketJoinGroup(env, socketNum(), groupAddr.s_addr)) {
if (DebugLevel >= 1) {
env << *this << ": failed to join group: "
<< env.getResultMsg() << "\n";
}
}
}
if (DebugLevel >= 2) env << *this << ": created\n";
}
void
Groupsock::changeDestinationParameters(struct in_addr const& newDestAddr,
Port newDestPort, int newDestTTL, unsigned sessionId) {
destRecord* dest;
for (dest = fDests; dest != NULL && dest->fSessionId != sessionId; dest = dest->fNext) {}
if (dest == NULL) { // There's no existing 'destRecord' for this "sessionId"; add a new one:
fDests = createNewDestRecord(newDestAddr, newDestPort, newDestTTL, sessionId, fDests);
return;
}
// "dest" is an existing 'destRecord' for this "sessionId"; change its values to the new ones:
struct in_addr destAddr = dest->fGroupEId.groupAddress();
if (newDestAddr.s_addr != 0) {
if (newDestAddr.s_addr != destAddr.s_addr
&& IsMulticastAddress(newDestAddr.s_addr)) {
// If the new destination is a multicast address, then we assume that
// we want to join it also. (If this is not in fact the case, then
// call "multicastSendOnly()" afterwards.)
socketLeaveGroup(env(), socketNum(), destAddr.s_addr);
socketJoinGroup(env(), socketNum(), newDestAddr.s_addr);
}
destAddr.s_addr = newDestAddr.s_addr;
}
portNumBits destPortNum = dest->fGroupEId.portNum();
if (newDestPort.num() != 0) {
if (newDestPort.num() != destPortNum
&& IsMulticastAddress(destAddr.s_addr)) {
// Also bind to the new port number:
changePort(newDestPort);
// And rejoin the multicast group:
socketJoinGroup(env(), socketNum(), destAddr.s_addr);
}
destPortNum = newDestPort.num();
}
u_int8_t destTTL = ttl();
if (newDestTTL != ~0) destTTL = (u_int8_t)newDestTTL;
dest->fGroupEId = GroupEId(destAddr, destPortNum, destTTL);
// Finally, remove any other 'destRecord's that might also have this "sessionId":
removeDestinationFrom(dest->fNext, sessionId);
}
void
Groupsock::changeDestinationParameters(struct in_addr const& newDestAddr,
Port newDestPort, int newDestTTL) {
if (fDests == NULL) return;
printf("changeDestinationParameters: %s:%d\n", inet_ntoa(newDestAddr), ntohs(newDestPort.num())); //jay
struct in_addr destAddr = fDests->fGroupEId.groupAddress();
if (newDestAddr.s_addr != 0) {
if (newDestAddr.s_addr != destAddr.s_addr
&& IsMulticastAddress(newDestAddr.s_addr)) {
// If the new destination is a multicast address, then we assume that
// we want to join it also. (If this is not in fact the case, then
// call "multicastSendOnly()" afterwards.)
socketLeaveGroup(env(), socketNum(), destAddr.s_addr);
socketJoinGroup(env(), socketNum(), newDestAddr.s_addr);
}
destAddr.s_addr = newDestAddr.s_addr;
}
portNumBits destPortNum = fDests->fGroupEId.portNum();
if (newDestPort.num() != 0) {
if (newDestPort.num() != destPortNum
&& IsMulticastAddress(destAddr.s_addr)) {
// Also bind to the new port number:
changePort(newDestPort);
// And rejoin the multicast group:
socketJoinGroup(env(), socketNum(), destAddr.s_addr);
}
destPortNum = newDestPort.num();
fDests->fPort = newDestPort;
}
u_int8_t destTTL = ttl();
if (newDestTTL != ~0) destTTL = (u_int8_t)newDestTTL;
fDests->fGroupEId = GroupEId(destAddr, destPortNum, destTTL);
}
netAddressBits ourIPAddress(UsageEnvironment& env) {
static netAddressBits ourAddress = 0;
int sock = -1;
struct in_addr testAddr;
if (ourAddress == 0) {
// We need to find our source address
struct sockaddr_in fromAddr;
fromAddr.sin_addr.s_addr = 0;
// Get our address by sending a (0-TTL) multicast packet,
// receiving it, and looking at the source address used.
// (This is kinda bogus, but it provides the best guarantee
// that other nodes will think our address is the same as we do.)
do {
loopbackWorks = 0; // until we learn otherwise
testAddr.s_addr = our_inet_addr("228.67.43.91"); // arbitrary
Port testPort(15947); // ditto
sock = setupDatagramSocket(env, testPort);
if (sock < 0) break;
if (!socketJoinGroup(env, sock, testAddr.s_addr)) break;
unsigned char testString[] = "hostIdTest";
unsigned testStringLength = sizeof testString;
if (!writeSocket(env, sock, testAddr, testPort, 0,
testString, testStringLength)) break;
unsigned char readBuffer[20];
struct timeval timeout;
timeout.tv_sec = 5;
timeout.tv_usec = 0;
int bytesRead = readSocket(env, sock,
readBuffer, sizeof readBuffer,
fromAddr, &timeout);
if (bytesRead == 0 // timeout occurred
|| bytesRead != (int)testStringLength
|| strncmp((char*)readBuffer, (char*)testString,
testStringLength) != 0) {
break;
}
loopbackWorks = 1;
} while (0);
if (!loopbackWorks) do {
// We couldn't find our address using multicast loopback
// so try instead to look it up directly.
char hostname[100];
hostname[0] = '\0';
#ifndef CRIS
gethostname(hostname, sizeof hostname);
#endif
if (hostname[0] == '\0') {
env.setResultErrMsg("initial gethostname() failed");
break;
}
#if defined(VXWORKS)
#include <hostLib.h>
if (ERROR == (ourAddress = hostGetByName( hostname ))) break;
#else
struct hostent* hstent
= (struct hostent*)gethostbyname(hostname);
if (hstent == NULL || hstent->h_length != 4) {
env.setResultErrMsg("initial gethostbyname() failed");
break;
}
// Take the first address that's not bad
// (This code, like many others, won't handle IPv6)
netAddressBits addr = 0;
for (unsigned i = 0; ; ++i) {
char* addrPtr = hstent->h_addr_list[i];
if (addrPtr == NULL) break;
netAddressBits a = *(netAddressBits*)addrPtr;
if (!badAddress(a)) {
addr = a;
break;
}
}
if (addr != 0) {
fromAddr.sin_addr.s_addr = addr;
} else {
env.setResultMsg("no address");
break;
}
} while (0);
// Make sure we have a good address:
netAddressBits from = fromAddr.sin_addr.s_addr;
if (badAddress(from)) {
char tmp[100];
sprintf(tmp,
"This computer has an invalid IP address: 0x%x",
(netAddressBits)(ntohl(from)));
env.setResultMsg(tmp);
from = 0;
}
ourAddress = from;
#endif
if (sock >= 0) {
socketLeaveGroup(env, sock, testAddr.s_addr);
closeSocket(sock);
}
// Use our newly-discovered IP address, and the current time,
// to initialize the random number generator's seed:
struct timeval timeNow;
gettimeofday(&timeNow, NULL);
unsigned seed = ourAddress^timeNow.tv_sec^timeNow.tv_usec;
our_srandom(seed);
}
return ourAddress;
}
void Groupsock::joinGroup(netAddressBits groupAddress)
{
socketJoinGroup(env(), socketNum(), groupAddress);
}
netAddressBits ourIPAddress(UsageEnvironment& env) {
static netAddressBits ourAddress = 0;
int sock = -1;
struct in_addr testAddr;
if (ReceivingInterfaceAddr != INADDR_ANY) {
// Hack: If we were told to receive on a specific interface address, then
// define this to be our ip address:
ourAddress = ReceivingInterfaceAddr;
}
if (ourAddress == 0) {
// We need to find our source address
struct sockaddr_in fromAddr;
fromAddr.sin_addr.s_addr = 0;
// Get our address by sending a (0-TTL) multicast packet,
// receiving it, and looking at the source address used.
// (This is kinda bogus, but it provides the best guarantee
// that other nodes will think our address is the same as we do.)
do {
loopbackWorks = 0; // until we learn otherwise
testAddr.s_addr = our_inet_addr("228.67.43.91"); // arbitrary
Port testPort(15947); // ditto
sock = setupDatagramSocket(env, testPort);
if (sock < 0) break;
if (!socketJoinGroup(env, sock, testAddr.s_addr)) break;
unsigned char testString[] = "hostIdTest";
unsigned testStringLength = sizeof testString;
if (!writeSocket(env, sock, testAddr, testPort.num(), 0,
testString, testStringLength)) break;
// Block until the socket is readable (with a 5-second timeout):
fd_set rd_set;
FD_ZERO(&rd_set);
FD_SET((unsigned)sock, &rd_set);
const unsigned numFds = sock+1;
struct timeval timeout;
timeout.tv_sec = 5;
timeout.tv_usec = 0;
int result = select(numFds, &rd_set, NULL, NULL, &timeout);
if (result <= 0) break;
unsigned char readBuffer[20];
int bytesRead = readSocket(env, sock,
readBuffer, sizeof readBuffer,
fromAddr);
if (bytesRead != (int)testStringLength
|| strncmp((char*)readBuffer, (char*)testString, testStringLength) != 0) {
break;
}
// We use this packet's source address, if it's good:
loopbackWorks = !badAddressForUs(fromAddr.sin_addr.s_addr);
} while (0);
if (sock >= 0) {
socketLeaveGroup(env, sock, testAddr.s_addr);
closeSocket(sock);
}
if (!loopbackWorks) do {
// We couldn't find our address using multicast loopback,
// so try instead to look it up directly - by first getting our host name, and then resolving this host name
char hostname[100];
hostname[0] = '\0';
int result = gethostname(hostname, sizeof hostname);
if (result != 0 || hostname[0] == '\0') {
env.setResultErrMsg("initial gethostname() failed");
break;
}
// Try to resolve "hostname" to an IP address:
NetAddressList addresses(hostname);
NetAddressList::Iterator iter(addresses);
NetAddress const* address;
// Take the first address that's not bad:
netAddressBits addr = 0;
while ((address = iter.nextAddress()) != NULL) {
netAddressBits a = *(netAddressBits*)(address->data());
if (!badAddressForUs(a)) {
addr = a;
break;
}
}
// Assign the address that we found to "fromAddr" (as if the 'loopback' method had worked), to simplify the code below:
fromAddr.sin_addr.s_addr = addr;
} while (0);
// Make sure we have a good address:
netAddressBits from = fromAddr.sin_addr.s_addr;
if (badAddressForUs(from)) {
char tmp[100];
sprintf(tmp, "This computer has an invalid IP address: %s", AddressString(from).val());
env.setResultMsg(tmp);
from = 0;
}
ourAddress = from;
// Use our newly-discovered IP address, and the current time,
// to initialize the random number generator's seed:
struct timeval timeNow;
gettimeofday(&timeNow, NULL);
unsigned seed = ourAddress^timeNow.tv_sec^timeNow.tv_usec;
our_srandom(seed);
}
return ourAddress;
}
