diff options
Diffstat (limited to 'unix/tclUnixSock.c')
| -rw-r--r-- | unix/tclUnixSock.c | 359 |
1 files changed, 242 insertions, 117 deletions
diff --git a/unix/tclUnixSock.c b/unix/tclUnixSock.c index 49a6460..96700ce 100644 --- a/unix/tclUnixSock.c +++ b/unix/tclUnixSock.c @@ -55,6 +55,8 @@ struct TcpState { TcpFdList fds; /* The file descriptors of the sockets. */ int flags; /* ORed combination of the bitfields defined * below. */ + int interest; /* Event types of interest */ + /* * Only needed for server sockets */ @@ -73,7 +75,7 @@ struct TcpState { struct addrinfo *myaddr; /* Iterator over myaddrlist. */ int filehandlers; /* Caches FileHandlers that get set up while * an async socket is not yet connected. */ - int status; /* Cache status of async socket. */ + int connectError; /* Cache SO_ERROR of async socket. */ int cachedBlocking; /* Cache blocking mode of async socket. */ }; @@ -82,8 +84,13 @@ struct TcpState { * structure. */ -#define TCP_ASYNC_SOCKET (1<<0) /* Asynchronous socket. */ +#define TCP_NONBLOCKING (1<<0) /* Socket with non-blocking I/O */ #define TCP_ASYNC_CONNECT (1<<1) /* Async connect in progress. */ +#define TCP_ASYNC_PENDING (1<<4) /* TcpConnect was called to + * process an async connect. This + * flag indicates that reentry is + * still pending */ +#define TCP_ASYNC_FAILED (1<<5) /* An async connect finally failed */ /* * The following defines the maximum length of the listen queue. This is the @@ -110,7 +117,7 @@ struct TcpState { * Static routines for this file: */ -static int CreateClientSocket(Tcl_Interp *interp, +static int TcpConnect(Tcl_Interp *interp, TcpState *state); static void TcpAccept(ClientData data, int mask); static int TcpBlockModeProc(ClientData data, int mode); @@ -129,6 +136,7 @@ static int TcpOutputProc(ClientData instanceData, const char *buf, int toWrite, int *errorCode); static void TcpWatchProc(ClientData instanceData, int mask); static int WaitForConnect(TcpState *statePtr, int *errorCodePtr); +static void WrapNotify(ClientData clientData, int mask); /* * This structure describes the channel type structure for TCP socket @@ -163,6 +171,21 @@ static TclInitProcessGlobalValueProc InitializeHostName; static ProcessGlobalValue hostName = {0, 0, NULL, NULL, InitializeHostName, NULL, NULL}; +#if 0 +/* printf debugging */ +void printaddrinfo(struct addrinfo *addrlist, char *prefix) +{ + char host[NI_MAXHOST], port[NI_MAXSERV]; + struct addrinfo *ai; + for (ai = addrlist; ai != NULL; ai = ai->ai_next) { + getnameinfo(ai->ai_addr, ai->ai_addrlen, + host, sizeof(host), + port, sizeof(port), + NI_NUMERICHOST|NI_NUMERICSERV); + fprintf(stderr,"%s: %s:%s\n", prefix, host, port); + } +} +#endif /* *---------------------------------------------------------------------- * @@ -349,9 +372,9 @@ TcpBlockModeProc( TcpState *statePtr = instanceData; if (mode == TCL_MODE_BLOCKING) { - CLEAR_BITS(statePtr->flags, TCP_ASYNC_SOCKET); + CLEAR_BITS(statePtr->flags, TCP_NONBLOCKING); } else { - SET_BITS(statePtr->flags, TCP_ASYNC_SOCKET); + SET_BITS(statePtr->flags, TCP_NONBLOCKING); } if (statePtr->flags & TCP_ASYNC_CONNECT) { statePtr->cachedBlocking = mode; @@ -368,48 +391,80 @@ TcpBlockModeProc( * * WaitForConnect -- * - * Wait for a connection on an asynchronously opened socket to be - * completed. In nonblocking mode, just test if the connection - * has completed without blocking. + * Check the state of an async connect process. If a connection + * attempt terminated, process it, which may finalize it or may + * start the next attempt. If a connect error occures, it is saved + * in statePtr->connectError to be reported by 'fconfigure -error'. + * + * There are two modes of operation, defined by errorCodePtr: + * * non-NULL: Called by explicite read/write command. block if + * socket is blocking. + * May return two error codes: + * * EWOULDBLOCK: if connect is still in progress + * * ENOTCONN: if connect failed. This would be the error + * message of a rect or sendto syscall so this is + * emulated here. + * * NULL: Called by a backround operation. Do not block and + * don't return any error code. * * Results: * 0 if the connection has completed, -1 if still in progress * or there is an error. * + * Side effects: + * Processes socket events off the system queue. + * May process asynchroneous connect. + * *---------------------------------------------------------------------- */ static int WaitForConnect( TcpState *statePtr, /* State of the socket. */ - int *errorCodePtr) /* Where to store errors? */ + int *errorCodePtr) { - int timeOut; /* How long to wait. */ - int state; /* Of calling TclWaitForFile. */ + int timeout; /* - * If an asynchronous connect is in progress, attempt to wait for it to - * complete before reading. + * Check if an async connect failed already and error reporting is demanded, + * return the error ENOTCONN */ - if (statePtr->flags & TCP_ASYNC_CONNECT) { - if (statePtr->flags & TCP_ASYNC_SOCKET) { - timeOut = 0; - } else { - timeOut = -1; - } - errno = 0; - state = TclUnixWaitForFile(statePtr->fds.fd, - TCL_WRITABLE | TCL_EXCEPTION, timeOut); - if (state & TCL_EXCEPTION) { - return -1; - } - if (state & TCL_WRITABLE) { - CLEAR_BITS(statePtr->flags, TCP_ASYNC_CONNECT); - } else if (timeOut == 0) { - *errorCodePtr = errno = EWOULDBLOCK; - return -1; - } + if (errorCodePtr != NULL && (statePtr->flags & TCP_ASYNC_FAILED)) { + *errorCodePtr = ENOTCONN; + return -1; + } + + /* + * Check if an async connect is running. If not return ok + */ + + if (!(statePtr->flags & TCP_ASYNC_PENDING)) { + return 0; + } + + if (errorCodePtr == NULL || (statePtr->flags & TCP_NONBLOCKING)) { + timeout = 0; + } else { + timeout = -1; + } + do { + if (TclUnixWaitForFile(statePtr->fds.fd, + TCL_WRITABLE | TCL_EXCEPTION, timeout) != 0) { + TcpConnect(NULL, statePtr); + } + /* Do this only once in the nonblocking case and repeat it until the + * socket is final when blocking */ + } while (timeout == -1 && statePtr->flags & TCP_ASYNC_CONNECT); + + if (errorCodePtr != NULL) { + if (statePtr->flags & TCP_ASYNC_PENDING) { + *errorCodePtr = EAGAIN; + return -1; + } else if (statePtr->connectError != 0) { + *errorCodePtr = ENOTCONN; + return -1; + } } return 0; } @@ -503,6 +558,7 @@ TcpOutputProc( return -1; } written = send(statePtr->fds.fd, buf, (size_t) toWrite, 0); + if (written > -1) { return written; } @@ -726,6 +782,8 @@ TcpGetOptionProc( TcpState *statePtr = instanceData; size_t len = 0; + WaitForConnect(statePtr, NULL); + if (optionName != NULL) { len = strlen(optionName); } @@ -733,27 +791,33 @@ TcpGetOptionProc( if ((len > 1) && (optionName[1] == 'e') && (strncmp(optionName, "-error", len) == 0)) { socklen_t optlen = sizeof(int); - int err, ret; - if (statePtr->status == 0) { - ret = getsockopt(statePtr->fds.fd, SOL_SOCKET, SO_ERROR, - (char *) &err, &optlen); - if (statePtr->flags & TCP_ASYNC_CONNECT) { - statePtr->status = err; - } - if (ret < 0) { - err = errno; - } + if (statePtr->flags & TCP_ASYNC_CONNECT) { + /* Suppress errors as long as we are not done */ + errno = 0; + } else if (statePtr->connectError != 0) { + errno = statePtr->connectError; + statePtr->connectError = 0; } else { - err = statePtr->status; - statePtr->status = 0; + int err; + getsockopt(statePtr->fds.fd, SOL_SOCKET, SO_ERROR, + (char *) &err, &optlen); + errno = err; + } + if (errno != 0) { + Tcl_DStringAppend(dsPtr, Tcl_ErrnoMsg(errno), -1); } - if (err != 0) { - Tcl_DStringAppend(dsPtr, Tcl_ErrnoMsg(err), -1); - } return TCL_OK; } + if ((len > 1) && (optionName[1] == 'c') && + (strncmp(optionName, "-connecting", len) == 0)) { + + Tcl_DStringAppend(dsPtr, + (statePtr->flags & TCP_ASYNC_CONNECT) ? "1" : "0", -1); + return TCL_OK; + } + if ((len == 0) || ((len > 1) && (optionName[1] == 'p') && (strncmp(optionName, "-peername", len) == 0))) { address peername; @@ -845,6 +909,35 @@ TcpGetOptionProc( */ static void +WrapNotify( + ClientData clientData, + int mask) +{ + TcpState *statePtr = (TcpState *) clientData; + int newmask = mask & statePtr->interest; + + if (newmask == 0) { + /* + * There was no overlap between the states the channel is + * interested in notifications for, and the states that are + * reported present on the file descriptor by select(). The + * only way that can happen is when the channel is interested + * in a writable condition, and only a readable state is reported + * present (see TcpWatchProc() below). In that case, signal back + * to the caller the writable state, which is really an error + * condition. As an extra check on that assumption, check for + * a non-zero value of errno before reporting an artificial + * writable state. + */ + if (errno == 0) { + return; + } + newmask = TCL_WRITABLE; + } + Tcl_NotifyChannel(statePtr->channel, newmask); +} + +static void TcpWatchProc( ClientData instanceData, /* The socket state. */ int mask) /* Events of interest; an OR-ed combination of @@ -862,13 +955,35 @@ TcpWatchProc( return; } - if (statePtr->flags & TCP_ASYNC_CONNECT) { + if (statePtr->flags & TCP_ASYNC_PENDING) { /* Async sockets use a FileHandler internally while connecting, so we * need to cache this request until the connection has succeeded. */ statePtr->filehandlers = mask; } else if (mask) { - Tcl_CreateFileHandler(statePtr->fds.fd, mask, - (Tcl_FileProc *) Tcl_NotifyChannel, statePtr->channel); + + /* + * Whether it is a bug or feature or otherwise, it is a fact + * of life that on at least some Linux kernels select() fails + * to report that a socket file descriptor is writable when + * the other end of the socket is closed. This is in contrast + * to the guarantees Tcl makes that its channels become + * writable and fire writable events on an error conditon. + * This has caused a leak of file descriptors in a state of + * background flushing. See Tcl ticket 1758a0b603. + * + * As a workaround, when our caller indicates an interest in + * writable notifications, we must tell the notifier built + * around select() that we are interested in the readable state + * of the file descriptor as well, as that is the only reliable + * means to get notified of error conditions. Then it is the + * task of WrapNotify() above to untangle the meaning of these + * channel states and report the chan events as best it can. + * We save a copy of the mask passed in to assist with that. + */ + + statePtr->interest = mask; + Tcl_CreateFileHandler(statePtr->fds.fd, mask|TCL_READABLE, + (Tcl_FileProc *) WrapNotify, statePtr); } else { Tcl_DeleteFileHandler(statePtr->fds.fd); } @@ -910,7 +1025,7 @@ TcpGetHandleProc( * * TcpAsyncCallback -- * - * Called by the event handler that CreateClientSocket sets up + * Called by the event handler that TcpConnect sets up * internally for [socket -async] to get notified when the * asyncronous connection attempt has succeeded or failed. * @@ -923,13 +1038,13 @@ TcpAsyncCallback( * TCL_READABLE, TCL_WRITABLE and * TCL_EXCEPTION. */ { - CreateClientSocket(NULL, clientData); + TcpConnect(NULL, clientData); } /* *---------------------------------------------------------------------- * - * CreateClientSocket -- + * TcpConnect -- * * This function opens a new socket in client mode. * @@ -957,33 +1072,32 @@ TcpAsyncCallback( */ static int -CreateClientSocket( +TcpConnect( Tcl_Interp *interp, /* For error reporting; can be NULL. */ - TcpState *state) + TcpState *statePtr) { socklen_t optlen; - int async_callback = (state->addr != NULL); - int status; - int async = state->flags & TCP_ASYNC_CONNECT; + int async_callback = statePtr->flags & TCP_ASYNC_PENDING; + int ret = -1, error = errno; + int async = statePtr->flags & TCP_ASYNC_CONNECT; if (async_callback) { goto reenter; } - for (state->addr = state->addrlist; state->addr != NULL; - state->addr = state->addr->ai_next) { - status = -1; + for (statePtr->addr = statePtr->addrlist; statePtr->addr != NULL; + statePtr->addr = statePtr->addr->ai_next) { - for (state->myaddr = state->myaddrlist; state->myaddr != NULL; - state->myaddr = state->myaddr->ai_next) { - int reuseaddr; + for (statePtr->myaddr = statePtr->myaddrlist; statePtr->myaddr != NULL; + statePtr->myaddr = statePtr->myaddr->ai_next) { + int reuseaddr = 1; /* * No need to try combinations of local and remote addresses of * different families. */ - if (state->myaddr->ai_family != state->addr->ai_family) { + if (statePtr->myaddr->ai_family != statePtr->addr->ai_family) { continue; } @@ -992,13 +1106,14 @@ CreateClientSocket( * iteration. */ - if (state->fds.fd >= 0) { - close(state->fds.fd); - state->fds.fd = -1; + if (statePtr->fds.fd >= 0) { + close(statePtr->fds.fd); + statePtr->fds.fd = -1; + errno = 0; } - state->fds.fd = socket(state->addr->ai_family, SOCK_STREAM, 0); - if (state->fds.fd < 0) { + statePtr->fds.fd = socket(statePtr->addr->ai_family, SOCK_STREAM, 0); + if (statePtr->fds.fd < 0) { continue; } @@ -1007,28 +1122,31 @@ CreateClientSocket( * inherited by child processes. */ - fcntl(state->fds.fd, F_SETFD, FD_CLOEXEC); + fcntl(statePtr->fds.fd, F_SETFD, FD_CLOEXEC); /* * Set kernel space buffering */ - TclSockMinimumBuffers(INT2PTR(state->fds.fd), SOCKET_BUFSIZE); + TclSockMinimumBuffers(INT2PTR(statePtr->fds.fd), SOCKET_BUFSIZE); if (async) { - status = TclUnixSetBlockingMode(state->fds.fd, - TCL_MODE_NONBLOCKING); - if (status < 0) { + ret = TclUnixSetBlockingMode(statePtr->fds.fd,TCL_MODE_NONBLOCKING); + if (ret < 0) { continue; - } - } + } + } - reuseaddr = 1; - (void) setsockopt(state->fds.fd, SOL_SOCKET, SO_REUSEADDR, + /* Gotta reset the error variable here, before we use it for the + * first time in this iteration. */ + error = 0; + + (void) setsockopt(statePtr->fds.fd, SOL_SOCKET, SO_REUSEADDR, (char *) &reuseaddr, sizeof(reuseaddr)); - status = bind(state->fds.fd, state->myaddr->ai_addr, - state->myaddr->ai_addrlen); - if (status < 0) { + ret = bind(statePtr->fds.fd, statePtr->myaddr->ai_addr, + statePtr->myaddr->ai_addrlen); + if (ret < 0) { + error = errno; continue; } @@ -1039,15 +1157,19 @@ CreateClientSocket( * in being informed when the connect completes. */ - status = connect(state->fds.fd, state->addr->ai_addr, - state->addr->ai_addrlen); - if (status < 0 && errno == EINPROGRESS) { - Tcl_CreateFileHandler(state->fds.fd, - TCL_WRITABLE|TCL_EXCEPTION, TcpAsyncCallback, state); + ret = connect(statePtr->fds.fd, statePtr->addr->ai_addr, + statePtr->addr->ai_addrlen); + if (ret < 0) error = errno; + if (ret < 0 && errno == EINPROGRESS) { + Tcl_CreateFileHandler(statePtr->fds.fd, + TCL_WRITABLE|TCL_EXCEPTION, TcpAsyncCallback, statePtr); + errno = EWOULDBLOCK; + SET_BITS(statePtr->flags, TCP_ASYNC_PENDING); return TCL_OK; reenter: - Tcl_DeleteFileHandler(state->fds.fd); + CLEAR_BITS(statePtr->flags, TCP_ASYNC_PENDING); + Tcl_DeleteFileHandler(statePtr->fds.fd); /* * Read the error state from the socket to see if the async @@ -1058,31 +1180,30 @@ CreateClientSocket( optlen = sizeof(int); - if (state->status == 0) { - getsockopt(state->fds.fd, SOL_SOCKET, SO_ERROR, - (char *) &status, &optlen); - state->status = status; - } else { - status = state->status; - state->status = 0; - } + getsockopt(statePtr->fds.fd, SOL_SOCKET, SO_ERROR, + (char *) &error, &optlen); + errno = error; } - if (status == 0) { + if (error == 0) { goto out; } } } out: - - CLEAR_BITS(state->flags, TCP_ASYNC_CONNECT); + statePtr->connectError = error; + CLEAR_BITS(statePtr->flags, TCP_ASYNC_CONNECT); if (async_callback) { /* * An asynchonous connection has finally succeeded or failed. */ - TcpWatchProc(state, state->filehandlers); - TclUnixSetBlockingMode(state->fds.fd, state->cachedBlocking); + TcpWatchProc(statePtr, statePtr->filehandlers); + TclUnixSetBlockingMode(statePtr->fds.fd, statePtr->cachedBlocking); + + if (error != 0) { + SET_BITS(statePtr->flags, TCP_ASYNC_FAILED); + } /* * We need to forward the writable event that brought us here, bcasue @@ -1093,8 +1214,11 @@ out: * the event mechanism one roundtrip through select(). */ - Tcl_NotifyChannel(state->channel, TCL_WRITABLE); - } else if (status != 0) { + if (statePtr->cachedBlocking == TCL_MODE_NONBLOCKING) { + Tcl_NotifyChannel(statePtr->channel, TCL_WRITABLE); + } + } + if (error != 0) { /* * Failure for either a synchronous connection, or an async one that * failed before it could enter background mode, e.g. because an @@ -1102,6 +1226,7 @@ out: */ if (interp != NULL) { + errno = error; Tcl_SetObjResult(interp, Tcl_ObjPrintf( "couldn't open socket: %s", Tcl_PosixError(interp))); } @@ -1138,7 +1263,7 @@ Tcl_OpenTcpClient( * connect. Otherwise we do a blocking * connect. */ { - TcpState *state; + TcpState *statePtr; const char *errorMsg = NULL; struct addrinfo *addrlist = NULL, *myaddrlist = NULL; char channelName[SOCK_CHAN_LENGTH]; @@ -1163,32 +1288,32 @@ Tcl_OpenTcpClient( /* * Allocate a new TcpState for this socket. */ - state = ckalloc(sizeof(TcpState)); - memset(state, 0, sizeof(TcpState)); - state->flags = async ? TCP_ASYNC_CONNECT : 0; - state->cachedBlocking = TCL_MODE_BLOCKING; - state->addrlist = addrlist; - state->myaddrlist = myaddrlist; - state->fds.fd = -1; + statePtr = ckalloc(sizeof(TcpState)); + memset(statePtr, 0, sizeof(TcpState)); + statePtr->flags = async ? TCP_ASYNC_CONNECT : 0; + statePtr->cachedBlocking = TCL_MODE_BLOCKING; + statePtr->addrlist = addrlist; + statePtr->myaddrlist = myaddrlist; + statePtr->fds.fd = -1; /* * Create a new client socket and wrap it in a channel. */ - if (CreateClientSocket(interp, state) != TCL_OK) { - TcpCloseProc(state, NULL); + if (TcpConnect(interp, statePtr) != TCL_OK) { + TcpCloseProc(statePtr, NULL); return NULL; } - sprintf(channelName, SOCK_TEMPLATE, (long) state); + sprintf(channelName, SOCK_TEMPLATE, (long) statePtr); - state->channel = Tcl_CreateChannel(&tcpChannelType, channelName, state, + statePtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName, statePtr, (TCL_READABLE | TCL_WRITABLE)); - if (Tcl_SetChannelOption(interp, state->channel, "-translation", + if (Tcl_SetChannelOption(interp, statePtr->channel, "-translation", "auto crlf") == TCL_ERROR) { - Tcl_Close(NULL, state->channel); + Tcl_Close(NULL, statePtr->channel); return NULL; } - return state->channel; + return statePtr->channel; } /* |