mirror of
https://github.com/samhocevar/rinetd.git
synced 2025-03-14 20:00:11 +08:00
Improve UDP connection handling.
Send a zero-sized UDP packet when first accessing the server; this makes TCP→UDP→TCP redirects work in both directions. Properly close UDP connections when the other end disconnects (TCP) or timeouts (UDP).
This commit is contained in:
Sam Hocevar
parent
b833d456dd
commit
37437a5c5b
@ -1,6 +1,6 @@
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# Process this file with autoconf to produce a configure script.
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AC_PREREQ(2.52)
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AC_INIT(rinetd, 0.63, sam@hocevar.net)
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AC_INIT(rinetd, 0.63.test, sam@hocevar.net)
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AC_CONFIG_AUX_DIR(.auto)
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AC_CONFIG_SRCDIR([getopt.h])
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AC_CONFIG_HEADER([config.h])
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83
rinetd.c
83
rinetd.c
@ -67,6 +67,9 @@ int const maxfd = 0;
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int maxfd = 0;
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#endif
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/* Global static buffer for UDP data. */
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static char globalUdpBuffer[65536];
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char *logFileName = NULL;
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char *pidLogFileName = NULL;
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int logFormatCommon = 0;
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@ -107,6 +110,7 @@ RinetdOptions options = {
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static void selectPass(void);
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static void handleWrite(ConnectionInfo *cnx, Socket *socket, Socket *other_socket);
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static void handleRead(ConnectionInfo *cnx, Socket *socket, Socket *other_socket);
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static void handleUdpRead(ConnectionInfo *cnx, char const *buffer, int bytes);
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static void handleClose(ConnectionInfo *cnx, Socket *socket, Socket *other_socket);
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static void handleAccept(ServerInfo const *srv);
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static ConnectionInfo *findAvailableConnection(void);
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@ -246,7 +250,8 @@ static void readConfiguration(char const *file) {
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void addServer(char *bindAddress, int bindPort, int bindProto,
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char *connectAddress, int connectPort, int connectProto,
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int serverTimeout) {
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int serverTimeout)
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{
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/* Turn all of this stuff into reasonable addresses */
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struct in_addr iaddr;
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if (getAddress(bindAddress, &iaddr) < 0) {
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@ -271,8 +276,7 @@ void addServer(char *bindAddress, int bindPort, int bindProto,
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setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
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(const char *) &tmp, sizeof(tmp));
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if (bind(fd, (struct sockaddr *)
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&saddr, sizeof(saddr)) == SOCKET_ERROR)
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{
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&saddr, sizeof(saddr)) == SOCKET_ERROR) {
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/* Warn -- don't exit. */
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syslog(LOG_ERR, "couldn't bind to "
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"address %s port %d (%m)\n",
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@ -290,6 +294,8 @@ void addServer(char *bindAddress, int bindPort, int bindProto,
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closesocket(fd);
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}
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/* Make socket nonblocking in TCP mode only, otherwise
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we may miss some data. */
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setSocketDefaults(fd);
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}
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@ -535,6 +541,18 @@ static void handleRead(ConnectionInfo *cnx, Socket *socket, Socket *other_socket
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socket->recvPos += got;
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}
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static void handleUdpRead(ConnectionInfo *cnx, char const *buffer, int bytes)
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{
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Socket *socket = &cnx->remote;
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int got = bytes < RINETD_BUFFER_SIZE - socket->recvPos
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? bytes : RINETD_BUFFER_SIZE - socket->recvPos;
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if (got > 0) {
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memcpy(socket->buffer + socket->recvPos, buffer, got);
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socket->recvBytes += got;
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socket->recvPos += got;
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}
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}
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static void handleWrite(ConnectionInfo *cnx, Socket *socket, Socket *other_socket)
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{
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if (cnx->coClosing && (socket->sentPos == other_socket->recvPos)) {
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@ -583,17 +601,25 @@ static void handleClose(ConnectionInfo *cnx, Socket *socket, Socket *other_socke
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/* Nothing to do in UDP mode */
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}
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socket->fd = INVALID_SOCKET;
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if (other_socket->fd != INVALID_SOCKET) {
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#if !defined __linux__ && !defined _WIN32
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/* Now set up the other end for a polite closing */
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/* Request a low-water mark equal to the entire
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output buffer, so the next write notification
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tells us for sure that we can close the socket. */
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int arg = 1024;
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setsockopt(other_socket->fd, SOL_SOCKET, SO_SNDLOWAT,
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&arg, sizeof(arg));
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if (other_socket->fd != INVALID_SOCKET) {
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if (other_socket->proto == protoTcp) {
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#if !defined __linux__ && !defined _WIN32
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/* Now set up the other end for a polite closing */
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/* Request a low-water mark equal to the entire
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output buffer, so the next write notification
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tells us for sure that we can close the socket. */
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int arg = 1024;
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setsockopt(other_socket->fd, SOL_SOCKET, SO_SNDLOWAT,
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&arg, sizeof(arg));
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#endif
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} else /* if (other_socket->proto == protoUdp) */ {
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if (other_socket == &cnx->local)
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closesocket(other_socket->fd);
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other_socket->fd = INVALID_SOCKET;
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}
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cnx->coLog = socket == &cnx->local ?
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logLocalClosedFirst : logRemoteClosedFirst;
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}
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@ -601,6 +627,8 @@ static void handleClose(ConnectionInfo *cnx, Socket *socket, Socket *other_socke
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static void handleAccept(ServerInfo const *srv)
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{
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int udpBytes = 0;
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struct sockaddr addr;
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SOCKLEN_T addrlen = sizeof(addr);
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@ -617,10 +645,12 @@ static void handleAccept(ServerInfo const *srv)
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setSocketDefaults(nfd);
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} else /* if (srv->fromProto == protoUdp) */ {
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/* In UDP mode, get remote address using recvfrom() and check
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for an existing connection from this client. */
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for an existing connection from this client. We need
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to read a lot of data otherwise the datagram contents
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may be lost later. */
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nfd = srv->fd;
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ssize_t ret = recvfrom(srv->fd, NULL, 0, MSG_PEEK,
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&addr, &addrlen);
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ssize_t ret = recvfrom(nfd, globalUdpBuffer,
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sizeof(globalUdpBuffer), 0, &addr, &addrlen);
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if (ret < 0) {
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if (GetLastError() == WSAEWOULDBLOCK) {
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return;
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@ -633,6 +663,8 @@ static void handleAccept(ServerInfo const *srv)
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return;
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}
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udpBytes = (int)ret;
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for (int i = 0; i < coTotal; ++i) {
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ConnectionInfo *cnx = &coInfo[i];
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struct sockaddr_in *addr_in = (struct sockaddr_in *)&addr;
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@ -641,7 +673,7 @@ static void handleAccept(ServerInfo const *srv)
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&& cnx->remoteAddress.sin_port == addr_in->sin_port
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&& cnx->remoteAddress.sin_addr.s_addr == addr_in->sin_addr.s_addr) {
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cnx->remoteTimeout = time(NULL) + srv->serverTimeout;
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handleRead(cnx, &cnx->remote, &cnx->local);
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handleUdpRead(cnx, globalUdpBuffer, udpBytes);
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return;
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}
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}
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@ -696,6 +728,9 @@ static void handleAccept(ServerInfo const *srv)
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return;
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}
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if (srv->toProto == protoTcp)
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setSocketDefaults(cnx->local.fd);
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#if 0 // You don't need bind(2) on a socket you'll use for connect(2).
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/* Bind the local socket */
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saddr.sin_family = AF_INET;
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@ -717,9 +752,6 @@ static void handleAccept(ServerInfo const *srv)
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memcpy(&saddr.sin_addr, &srv->localAddr, sizeof(struct in_addr));
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saddr.sin_port = srv->localPort;
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if (srv->toProto == protoTcp)
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setSocketDefaults(cnx->local.fd);
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if (connect(cnx->local.fd, (struct sockaddr *)&saddr,
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sizeof(struct sockaddr_in)) == SOCKET_ERROR)
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{
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@ -737,6 +769,19 @@ static void handleAccept(ServerInfo const *srv)
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}
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}
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/* Send a zero-size UDP packet to simulate a connection */
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if (srv->toProto == protoUdp) {
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int got = sendto(cnx->local.fd, NULL, 0, 0,
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&saddr, (SOCKLEN_T)sizeof(saddr));
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/* FIXME: we ignore errors here... is it safe? */
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(void)got;
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}
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/* Send UDP data to the other socket */
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if (srv->fromProto == protoUdp) {
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handleUdpRead(cnx, globalUdpBuffer, udpBytes);
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}
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#ifndef _WIN32
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if (cnx->local.fd > maxfd) {
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maxfd = cnx->local.fd;
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