/** * @file net.cpp * @brief Cross-platform routines for sending and receiving packets. * * $LicenseInfo:firstyear=2000&license=viewergpl$ * * Copyright (c) 2000-2009, Linden Research, Inc. * * Second Life Viewer Source Code * The source code in this file ("Source Code") is provided by Linden Lab * to you under the terms of the GNU General Public License, version 2.0 * ("GPL"), unless you have obtained a separate licensing agreement * ("Other License"), formally executed by you and Linden Lab. Terms of * the GPL can be found in doc/GPL-license.txt in this distribution, or * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2 * * There are special exceptions to the terms and conditions of the GPL as * it is applied to this Source Code. View the full text of the exception * in the file doc/FLOSS-exception.txt in this software distribution, or * online at * http://secondlifegrid.net/programs/open_source/licensing/flossexception * * By copying, modifying or distributing this software, you acknowledge * that you have read and understood your obligations described above, * and agree to abide by those obligations. * * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY, * COMPLETENESS OR PERFORMANCE. * $/LicenseInfo$ */ #include "linden_common.h" #include "net.h" // system library includes #include <stdexcept> #if LL_WINDOWS #define WIN32_LEAN_AND_MEAN #include <winsock2.h> #include <windows.h> #else #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <fcntl.h> #include <errno.h> #endif // linden library includes #include "llerror.h" #include "llhost.h" #include "lltimer.h" #include "indra_constants.h" // Globals #if LL_WINDOWS SOCKADDR_IN stDstAddr; SOCKADDR_IN stSrcAddr; SOCKADDR_IN stLclAddr; static WSADATA stWSAData; #else struct sockaddr_in stDstAddr; struct sockaddr_in stSrcAddr; struct sockaddr_in stLclAddr; #if LL_DARWIN #ifndef _SOCKLEN_T #define _SOCKLEN_T typedef int socklen_t; #endif #endif #endif static U32 gsnReceivingIFAddr = INVALID_HOST_IP_ADDRESS; // Address to which datagram was sent const char* LOOPBACK_ADDRESS_STRING = "127.0.0.1"; const char* BROADCAST_ADDRESS_STRING = "255.255.255.255"; #if LL_DARWIN // Mac OS X returns an error when trying to set these to 400000. Smaller values succeed. const int SEND_BUFFER_SIZE = 200000; const int RECEIVE_BUFFER_SIZE = 200000; #else // LL_DARWIN const int SEND_BUFFER_SIZE = 400000; const int RECEIVE_BUFFER_SIZE = 400000; #endif // LL_DARWIN // universal functions (cross-platform) LLHost get_sender() { return LLHost(stSrcAddr.sin_addr.s_addr, ntohs(stSrcAddr.sin_port)); } U32 get_sender_ip(void) { return stSrcAddr.sin_addr.s_addr; } U32 get_sender_port() { return ntohs(stSrcAddr.sin_port); } LLHost get_receiving_interface() { return LLHost(gsnReceivingIFAddr, INVALID_PORT); } U32 get_receiving_interface_ip(void) { return gsnReceivingIFAddr; } const char* u32_to_ip_string(U32 ip) { static char buffer[MAXADDRSTR]; /* Flawfinder: ignore */ // Convert the IP address into a string in_addr in; in.s_addr = ip; char* result = inet_ntoa(in); // NULL indicates error in conversion if (result != NULL) { strncpy( buffer, result, MAXADDRSTR ); /* Flawfinder: ignore */ buffer[MAXADDRSTR-1] = '\0'; return buffer; } else { return "(bad IP addr)"; } } // Returns ip_string if successful, NULL if not. Copies into ip_string char *u32_to_ip_string(U32 ip, char *ip_string) { char *result; in_addr in; // Convert the IP address into a string in.s_addr = ip; result = inet_ntoa(in); // NULL indicates error in conversion if (result != NULL) { //the function signature needs to change to pass in the lengfth of first and last. strcpy(ip_string, result); /*Flawfinder: ignore*/ return ip_string; } else { return NULL; } } // Wrapper for inet_addr() U32 ip_string_to_u32(const char* ip_string) { // *NOTE: Windows doesn't support inet_aton(), so we are using // inet_addr(). Unfortunately, INADDR_NONE == INADDR_BROADCAST, so // we have to check whether the input is a broadcast address before // deciding that @ip_string is invalid. // // Also, our definition of INVALID_HOST_IP_ADDRESS doesn't allow us to // use wildcard addresses. -Ambroff U32 ip = inet_addr(ip_string); if (ip == INADDR_NONE && strncmp(ip_string, BROADCAST_ADDRESS_STRING, MAXADDRSTR) != 0) { llwarns << "ip_string_to_u32() failed, Error: Invalid IP string '" << ip_string << "'" << llendl; return INVALID_HOST_IP_ADDRESS; } return ip; } ////////////////////////////////////////////////////////////////////////////////////////// // Windows Versions ////////////////////////////////////////////////////////////////////////////////////////// #if LL_WINDOWS S32 start_net(S32& socket_out, int& nPort) { // Create socket, make non-blocking // Init WinSock int nRet; int hSocket; int snd_size = SEND_BUFFER_SIZE; int rec_size = RECEIVE_BUFFER_SIZE; int buff_size = 4; // Initialize windows specific stuff if(WSAStartup(0x0202, &stWSAData)) { S32 err = WSAGetLastError(); WSACleanup(); LL_WARNS("AppInit") << "Windows Sockets initialization failed, err " << err << LL_ENDL; return 1; } // Get a datagram socket hSocket = (int)socket(AF_INET, SOCK_DGRAM, 0); if (hSocket == INVALID_SOCKET) { S32 err = WSAGetLastError(); WSACleanup(); LL_WARNS("AppInit") << "socket() failed, err " << err << LL_ENDL; return 2; } // Name the socket (assign the local port number to receive on) stLclAddr.sin_family = AF_INET; stLclAddr.sin_addr.s_addr = htonl(INADDR_ANY); stLclAddr.sin_port = htons(nPort); S32 attempt_port = nPort; LL_DEBUGS("AppInit") << "attempting to connect on port " << attempt_port << LL_ENDL; nRet = bind(hSocket, (struct sockaddr*) &stLclAddr, sizeof(stLclAddr)); if (nRet == SOCKET_ERROR) { // If we got an address in use error... if (WSAGetLastError() == WSAEADDRINUSE) { // Try all ports from PORT_DISCOVERY_RANGE_MIN to PORT_DISCOVERY_RANGE_MAX for(attempt_port = PORT_DISCOVERY_RANGE_MIN; attempt_port <= PORT_DISCOVERY_RANGE_MAX; attempt_port++) { stLclAddr.sin_port = htons(attempt_port); LL_DEBUGS("AppInit") << "trying port " << attempt_port << LL_ENDL; nRet = bind(hSocket, (struct sockaddr*) &stLclAddr, sizeof(stLclAddr)); if (!(nRet == SOCKET_ERROR && WSAGetLastError() == WSAEADDRINUSE)) { break; } } if (nRet == SOCKET_ERROR) { LL_WARNS("AppInit") << "startNet() : Couldn't find available network port." << LL_ENDL; // Fail gracefully here in release return 3; } } else // Some other socket error { LL_WARNS("AppInit") << llformat("bind() port: %d failed, Err: %d\n", nPort, WSAGetLastError()) << LL_ENDL; // Fail gracefully in release. return 4; } } sockaddr_in socket_address; S32 socket_address_size = sizeof(socket_address); getsockname(hSocket, (SOCKADDR*) &socket_address, &socket_address_size); attempt_port = ntohs(socket_address.sin_port); LL_INFOS("AppInit") << "connected on port " << attempt_port << LL_ENDL; nPort = attempt_port; // Set socket to be non-blocking unsigned long argp = 1; nRet = ioctlsocket (hSocket, FIONBIO, &argp); if (nRet == SOCKET_ERROR) { printf("Failed to set socket non-blocking, Err: %d\n", WSAGetLastError()); } // set a large receive buffer nRet = setsockopt(hSocket, SOL_SOCKET, SO_RCVBUF, (char *)&rec_size, buff_size); if (nRet) { LL_INFOS("AppInit") << "Can't set receive buffer size!" << LL_ENDL; } nRet = setsockopt(hSocket, SOL_SOCKET, SO_SNDBUF, (char *)&snd_size, buff_size); if (nRet) { LL_INFOS("AppInit") << "Can't set send buffer size!" << LL_ENDL; } getsockopt(hSocket, SOL_SOCKET, SO_RCVBUF, (char *)&rec_size, &buff_size); getsockopt(hSocket, SOL_SOCKET, SO_SNDBUF, (char *)&snd_size, &buff_size); LL_DEBUGS("AppInit") << "startNet - receive buffer size : " << rec_size << LL_ENDL; LL_DEBUGS("AppInit") << "startNet - send buffer size : " << snd_size << LL_ENDL; // Setup a destination address stDstAddr.sin_family = AF_INET; stDstAddr.sin_addr.s_addr = INVALID_HOST_IP_ADDRESS; stDstAddr.sin_port = htons(nPort); socket_out = hSocket; return 0; } void end_net(S32& socket_out) { if (socket_out >= 0) { shutdown(socket_out, SD_BOTH); closesocket(socket_out); } WSACleanup(); } S32 receive_packet(int hSocket, char * receiveBuffer) { // Receives data asynchronously from the socket set by initNet(). // Returns the number of bytes received into dataReceived, or zero // if there is no data received. int nRet; int addr_size = sizeof(struct sockaddr_in); nRet = recvfrom(hSocket, receiveBuffer, NET_BUFFER_SIZE, 0, (struct sockaddr*)&stSrcAddr, &addr_size); if (nRet == SOCKET_ERROR ) { if (WSAEWOULDBLOCK == WSAGetLastError()) return 0; if (WSAECONNRESET == WSAGetLastError()) return 0; llinfos << "receivePacket() failed, Error: " << WSAGetLastError() << llendl; } return nRet; } // Returns TRUE on success. BOOL send_packet(int hSocket, const char *sendBuffer, int size, U32 recipient, int nPort) { // Sends a packet to the address set in initNet // int nRet = 0; U32 last_error = 0; stDstAddr.sin_addr.s_addr = recipient; stDstAddr.sin_port = htons(nPort); do { nRet = sendto(hSocket, sendBuffer, size, 0, (struct sockaddr*)&stDstAddr, sizeof(stDstAddr)); if (nRet == SOCKET_ERROR ) { last_error = WSAGetLastError(); if (last_error != WSAEWOULDBLOCK) { // WSAECONNRESET - I think this is caused by an ICMP "connection refused" // message being sent back from a Linux box... I'm not finding helpful // documentation or web pages on this. The question is whether the packet // actually got sent or not. Based on the structure of this code, I would // assume it is. JNC 2002.01.18 if (WSAECONNRESET == WSAGetLastError()) { return TRUE; } llinfos << "sendto() failed to " << u32_to_ip_string(recipient) << ":" << nPort << ", Error " << last_error << llendl; } } } while ( (nRet == SOCKET_ERROR) &&(last_error == WSAEWOULDBLOCK)); return (nRet != SOCKET_ERROR); } ////////////////////////////////////////////////////////////////////////////////////////// // Linux Versions ////////////////////////////////////////////////////////////////////////////////////////// #else // Create socket, make non-blocking S32 start_net(S32& socket_out, int& nPort) { int hSocket, nRet; int snd_size = SEND_BUFFER_SIZE; int rec_size = RECEIVE_BUFFER_SIZE; socklen_t buff_size = 4; // Create socket hSocket = socket(AF_INET, SOCK_DGRAM, 0); if (hSocket < 0) { llwarns << "socket() failed" << llendl; return 1; } if (NET_USE_OS_ASSIGNED_PORT == nPort) { // Although bind is not required it will tell us which port we were // assigned to. stLclAddr.sin_family = AF_INET; stLclAddr.sin_addr.s_addr = htonl(INADDR_ANY); stLclAddr.sin_port = htons(0); llinfos << "attempting to connect on OS assigned port" << llendl; nRet = bind(hSocket, (struct sockaddr*) &stLclAddr, sizeof(stLclAddr)); if (nRet < 0) { llwarns << "Failed to bind on an OS assigned port error: " << nRet << llendl; } else { sockaddr_in socket_info; socklen_t len = sizeof(sockaddr_in); int err = getsockname(hSocket, (sockaddr*)&socket_info, &len); llinfos << "Get socket returned: " << err << " length " << len << llendl; nPort = ntohs(socket_info.sin_port); llinfos << "Assigned port: " << nPort << llendl; } } else { // Name the socket (assign the local port number to receive on) stLclAddr.sin_family = AF_INET; stLclAddr.sin_addr.s_addr = htonl(INADDR_ANY); stLclAddr.sin_port = htons(nPort); U32 attempt_port = nPort; llinfos << "attempting to connect on port " << attempt_port << llendl; nRet = bind(hSocket, (struct sockaddr*) &stLclAddr, sizeof(stLclAddr)); if (nRet < 0) { // If we got an address in use error... if (errno == EADDRINUSE) { // Try all ports from PORT_DISCOVERY_RANGE_MIN to PORT_DISCOVERY_RANGE_MAX for(attempt_port = PORT_DISCOVERY_RANGE_MIN; attempt_port <= PORT_DISCOVERY_RANGE_MAX; attempt_port++) { stLclAddr.sin_port = htons(attempt_port); llinfos << "trying port " << attempt_port << llendl; nRet = bind(hSocket, (struct sockaddr*) &stLclAddr, sizeof(stLclAddr)); if (!((nRet < 0) && (errno == EADDRINUSE))) { break; } } if (nRet < 0) { llwarns << "startNet() : Couldn't find available network port." << llendl; // Fail gracefully in release. return 3; } } // Some other socket error else { llwarns << llformat ("bind() port: %d failed, Err: %s\n", nPort, strerror(errno)) << llendl; // Fail gracefully in release. return 4; } } llinfos << "connected on port " << attempt_port << llendl; nPort = attempt_port; } // Set socket to be non-blocking fcntl(hSocket, F_SETFL, O_NONBLOCK); // set a large receive buffer nRet = setsockopt(hSocket, SOL_SOCKET, SO_RCVBUF, (char *)&rec_size, buff_size); if (nRet) { llinfos << "Can't set receive size!" << llendl; } nRet = setsockopt(hSocket, SOL_SOCKET, SO_SNDBUF, (char *)&snd_size, buff_size); if (nRet) { llinfos << "Can't set send size!" << llendl; } getsockopt(hSocket, SOL_SOCKET, SO_RCVBUF, (char *)&rec_size, &buff_size); getsockopt(hSocket, SOL_SOCKET, SO_SNDBUF, (char *)&snd_size, &buff_size); llinfos << "startNet - receive buffer size : " << rec_size << llendl; llinfos << "startNet - send buffer size : " << snd_size << llendl; #if LL_LINUX // Turn on recipient address tracking { int use_pktinfo = 1; if( setsockopt( hSocket, SOL_IP, IP_PKTINFO, &use_pktinfo, sizeof(use_pktinfo) ) == -1 ) { llwarns << "No IP_PKTINFO available" << llendl; } else { llinfos << "IP_PKKTINFO enabled" << llendl; } } #endif // Setup a destination address char achMCAddr[MAXADDRSTR] = "127.0.0.1"; /* Flawfinder: ignore */ stDstAddr.sin_family = AF_INET; stDstAddr.sin_addr.s_addr = ip_string_to_u32(achMCAddr); stDstAddr.sin_port = htons(nPort); socket_out = hSocket; return 0; } void end_net(S32& socket_out) { if (socket_out >= 0) { close(socket_out); } } #if LL_LINUX static int recvfrom_destip( int socket, void *buf, int len, struct sockaddr *from, socklen_t *fromlen, U32 *dstip ) { int size; struct iovec iov[1]; char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo))]; struct cmsghdr *cmsgptr; struct msghdr msg = {0}; iov[0].iov_base = buf; iov[0].iov_len = len; memset( &msg, 0, sizeof msg ); msg.msg_name = from; msg.msg_namelen = *fromlen; msg.msg_iov = iov; msg.msg_iovlen = 1; msg.msg_control = &cmsg; msg.msg_controllen = sizeof(cmsg); size = recvmsg( socket, &msg, 0 ); if( size == -1 ) { return -1; } for( cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL; cmsgptr = CMSG_NXTHDR( &msg, cmsgptr ) ) { if( cmsgptr->cmsg_level == SOL_IP && cmsgptr->cmsg_type == IP_PKTINFO ) { in_pktinfo *pktinfo = (in_pktinfo *)CMSG_DATA(cmsgptr); if( pktinfo ) { // Two choices. routed and specified. ipi_addr is routed, ipi_spec_dst is // routed. We should stay with specified until we go to multiple // interfaces *dstip = pktinfo->ipi_spec_dst.s_addr; } } } return size; } #endif int receive_packet(int hSocket, char * receiveBuffer) { // Receives data asynchronously from the socket set by initNet(). // Returns the number of bytes received into dataReceived, or zero // if there is no data received. // or -1 if an error occured! int nRet; socklen_t addr_size = sizeof(struct sockaddr_in); gsnReceivingIFAddr = INVALID_HOST_IP_ADDRESS; #if LL_LINUX nRet = recvfrom_destip(hSocket, receiveBuffer, NET_BUFFER_SIZE, (struct sockaddr*)&stSrcAddr, &addr_size, &gsnReceivingIFAddr); #else int recv_flags = 0; nRet = recvfrom(hSocket, receiveBuffer, NET_BUFFER_SIZE, recv_flags, (struct sockaddr*)&stSrcAddr, &addr_size); #endif if (nRet == -1) { // To maintain consistency with the Windows implementation, return a zero for size on error. return 0; } // Uncomment for testing if/when implementing for Mac or Windows: // llinfos << "Received datagram to in addr " << u32_to_ip_string(get_receiving_interface_ip()) << llendl; return nRet; } BOOL send_packet(int hSocket, const char * sendBuffer, int size, U32 recipient, int nPort) { int ret; BOOL success; BOOL resend; S32 send_attempts = 0; stDstAddr.sin_addr.s_addr = recipient; stDstAddr.sin_port = htons(nPort); do { ret = sendto(hSocket, sendBuffer, size, 0, (struct sockaddr*)&stDstAddr, sizeof(stDstAddr)); send_attempts++; if (ret >= 0) { // successful send success = TRUE; resend = FALSE; } else { // send failed, check to see if we should resend success = FALSE; if (errno == EAGAIN) { // say nothing, just repeat send llinfos << "sendto() reported buffer full, resending (attempt " << send_attempts << ")" << llendl; llinfos << inet_ntoa(stDstAddr.sin_addr) << ":" << nPort << llendl; resend = TRUE; } else if (errno == ECONNREFUSED) { // response to ICMP connection refused message on earlier send llinfos << "sendto() reported connection refused, resending (attempt " << send_attempts << ")" << llendl; llinfos << inet_ntoa(stDstAddr.sin_addr) << ":" << nPort << llendl; resend = TRUE; } else { // some other error llinfos << "sendto() failed: " << errno << ", " << strerror(errno) << llendl; llinfos << inet_ntoa(stDstAddr.sin_addr) << ":" << nPort << llendl; resend = FALSE; } } } while ( resend && send_attempts < 3); if (send_attempts >= 3) { llinfos << "sendPacket() bailed out of send!" << llendl; return FALSE; } return success; } #endif //EOF