net.cpp
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上传日期:2021-03-01
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- /**
- * @file net.cpp
- * @brief Cross-platform routines for sending and receiving packets.
- *
- * $LicenseInfo:firstyear=2000&license=viewergpl$
- *
- * Copyright (c) 2000-2010, 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] = ' ';
- 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: %dn", 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: %dn",
- 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: %sn", 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