/* * tclUnixSock.c -- * * This file contains Unix-specific socket related code. * * Copyright (c) 1995 Sun Microsystems, Inc. * * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. */ #include "tclInt.h" /* * Helper macros to make parts of this file clearer. The macros do exactly * what they say on the tin. :-) They also only ever refer to their arguments * once, and so can be used without regard to side effects. */ #define SET_BITS(var, bits) ((var) |= (bits)) #define CLEAR_BITS(var, bits) ((var) &= ~(bits)) /* "sock" + a pointer in hex + \0 */ #define SOCK_CHAN_LENGTH (4 + sizeof(void *) * 2 + 1) #define SOCK_TEMPLATE "sock%lx" #undef SOCKET /* Possible conflict with win32 SOCKET */ /* * This is needed to comply with the strict aliasing rules of GCC, but it also * simplifies casting between the different sockaddr types. */ typedef union { struct sockaddr sa; struct sockaddr_in sa4; struct sockaddr_in6 sa6; struct sockaddr_storage sas; } address; /* * This structure describes per-instance state of a tcp based channel. */ typedef struct TcpState TcpState; typedef struct TcpFdList { TcpState *statePtr; int fd; struct TcpFdList *next; } TcpFdList; struct TcpState { Tcl_Channel channel; /* Channel associated with this file. */ int testFlags; /* bit field for tests. Is set by testsocket * test procedure */ 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 */ Tcl_TcpAcceptProc *acceptProc; /* Proc to call on accept. */ ClientData acceptProcData; /* The data for the accept proc. */ /* * Only needed for client sockets */ struct addrinfo *addrlist; /* Addresses to connect to. */ struct addrinfo *addr; /* Iterator over addrlist. */ struct addrinfo *myaddrlist;/* Local address. */ struct addrinfo *myaddr; /* Iterator over myaddrlist. */ int filehandlers; /* Caches FileHandlers that get set up while * an async socket is not yet connected. */ int connectError; /* Cache SO_ERROR of async socket. */ int cachedBlocking; /* Cache blocking mode of async socket. */ }; /* * These bits may be ORed together into the "flags" field of a TcpState * structure. */ #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 */ /* * These bits may be ORed together into the "testFlags" field of a TcpState * structure. */ #define TCP_ASYNC_TEST_MODE (1<<0) /* Async testing activated * Do not automatically continue connection * process */ /* * The following defines the maximum length of the listen queue. This is the * number of outstanding yet-to-be-serviced requests for a connection on a * server socket, more than this number of outstanding requests and the * connection request will fail. */ #ifndef SOMAXCONN # define SOMAXCONN 100 #elif (SOMAXCONN < 100) # undef SOMAXCONN # define SOMAXCONN 100 #endif /* SOMAXCONN < 100 */ /* * The following defines how much buffer space the kernel should maintain for * a socket. */ #define SOCKET_BUFSIZE 4096 /* * Static routines for this file: */ static int TcpConnect(Tcl_Interp *interp, TcpState *state); static void TcpAccept(ClientData data, int mask); static int TcpBlockModeProc(ClientData data, int mode); static int TcpCloseProc(ClientData instanceData, Tcl_Interp *interp); static int TcpClose2Proc(ClientData instanceData, Tcl_Interp *interp, int flags); static int TcpGetHandleProc(ClientData instanceData, int direction, ClientData *handlePtr); static int TcpGetOptionProc(ClientData instanceData, Tcl_Interp *interp, const char *optionName, Tcl_DString *dsPtr); static int TcpInputProc(ClientData instanceData, char *buf, int toRead, int *errorCode); 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 * based IO: */ static const Tcl_ChannelType tcpChannelType = { "tcp", /* Type name. */ TCL_CHANNEL_VERSION_5, /* v5 channel */ TcpCloseProc, /* Close proc. */ TcpInputProc, /* Input proc. */ TcpOutputProc, /* Output proc. */ NULL, /* Seek proc. */ NULL, /* Set option proc. */ TcpGetOptionProc, /* Get option proc. */ TcpWatchProc, /* Initialize notifier. */ TcpGetHandleProc, /* Get OS handles out of channel. */ TcpClose2Proc, /* Close2 proc. */ TcpBlockModeProc, /* Set blocking or non-blocking mode.*/ NULL, /* flush proc. */ NULL, /* handler proc. */ NULL, /* wide seek proc. */ NULL, /* thread action proc. */ NULL /* truncate proc. */ }; /* * The following variable holds the network name of this host. */ 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 /* *---------------------------------------------------------------------- * * InitializeHostName -- * * This routine sets the process global value of the name of the local * host on which the process is running. * * Results: * None. * *---------------------------------------------------------------------- */ static void InitializeHostName( char **valuePtr, int *lengthPtr, Tcl_Encoding *encodingPtr) { const char *native = NULL; #ifndef NO_UNAME struct utsname u; struct hostent *hp; memset(&u, (int) 0, sizeof(struct utsname)); if (uname(&u) > -1) { /* INTL: Native. */ hp = TclpGetHostByName(u.nodename); /* INTL: Native. */ if (hp == NULL) { /* * Sometimes the nodename is fully qualified, but gets truncated * as it exceeds SYS_NMLN. See if we can just get the immediate * nodename and get a proper answer that way. */ char *dot = strchr(u.nodename, '.'); if (dot != NULL) { char *node = ckalloc(dot - u.nodename + 1); memcpy(node, u.nodename, (size_t) (dot - u.nodename)); node[dot - u.nodename] = '\0'; hp = TclpGetHostByName(node); ckfree(node); } } if (hp != NULL) { native = hp->h_name; } else { native = u.nodename; } } if (native == NULL) { native = tclEmptyStringRep; } #else /* !NO_UNAME */ /* * Uname doesn't exist; try gethostname instead. * * There is no portable macro for the maximum length of host names * returned by gethostbyname(). We should only trust SYS_NMLN if it is at * least 255 + 1 bytes to comply with DNS host name limits. * * Note: SYS_NMLN is a restriction on "uname" not on gethostbyname! * * For example HP-UX 10.20 has SYS_NMLN == 9, while gethostbyname() can * return a fully qualified name from DNS of up to 255 bytes. * * Fix suggested by Viktor Dukhovni (viktor@esm.com) */ # if defined(SYS_NMLN) && (SYS_NMLEN >= 256) char buffer[SYS_NMLEN]; # else char buffer[256]; # endif if (gethostname(buffer, sizeof(buffer)) > -1) { /* INTL: Native. */ native = buffer; } #endif /* NO_UNAME */ *encodingPtr = Tcl_GetEncoding(NULL, NULL); *lengthPtr = strlen(native); *valuePtr = ckalloc((*lengthPtr) + 1); memcpy(*valuePtr, native, (size_t)(*lengthPtr)+1); } /* *---------------------------------------------------------------------- * * Tcl_GetHostName -- * * Returns the name of the local host. * * Results: * A string containing the network name for this machine, or an empty * string if we can't figure out the name. The caller must not modify or * free this string. * * Side effects: * Caches the name to return for future calls. * *---------------------------------------------------------------------- */ const char * Tcl_GetHostName(void) { return Tcl_GetString(TclGetProcessGlobalValue(&hostName)); } /* *---------------------------------------------------------------------- * * TclpHasSockets -- * * Detect if sockets are available on this platform. * * Results: * Returns TCL_OK. * * Side effects: * None. * *---------------------------------------------------------------------- */ int TclpHasSockets( Tcl_Interp *interp) /* Not used. */ { return TCL_OK; } /* *---------------------------------------------------------------------- * * TclpFinalizeSockets -- * * Performs per-thread socket subsystem finalization. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ void TclpFinalizeSockets(void) { return; } /* *---------------------------------------------------------------------- * * TcpBlockModeProc -- * * This function is invoked by the generic IO level to set blocking and * nonblocking mode on a TCP socket based channel. * * Results: * 0 if successful, errno when failed. * * Side effects: * Sets the device into blocking or nonblocking mode. * *---------------------------------------------------------------------- */ /* ARGSUSED */ static int TcpBlockModeProc( ClientData instanceData, /* Socket state. */ int mode) /* The mode to set. Can be one of * TCL_MODE_BLOCKING or * TCL_MODE_NONBLOCKING. */ { TcpState *statePtr = instanceData; if (mode == TCL_MODE_BLOCKING) { CLEAR_BITS(statePtr->flags, TCP_NONBLOCKING); } else { SET_BITS(statePtr->flags, TCP_NONBLOCKING); } if (statePtr->flags & TCP_ASYNC_CONNECT) { statePtr->cachedBlocking = mode; return 0; } if (TclUnixSetBlockingMode(statePtr->fds.fd, mode) < 0) { return errno; } return 0; } /* *---------------------------------------------------------------------- * * WaitForConnect -- * * 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) { int timeout; /* * Check if an async connect failed already and error reporting is demanded, * return the error ENOTCONN */ 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; } /* * In socket test mode do not continue with the connect * Exceptions are: * - Call by recv/send and blocking socket * (errorCodePtr != NULL && ! flags & TCP_NONBLOCKING) */ if ( (statePtr->testFlags & TCP_ASYNC_TEST_MODE) && ! (errorCodePtr != NULL && ! (statePtr->flags & TCP_NONBLOCKING))) { *errorCodePtr = EWOULDBLOCK; return -1; } 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; } /* *---------------------------------------------------------------------- * * TcpInputProc -- * * This function is invoked by the generic IO level to read input from a * TCP socket based channel. * * NOTE: We cannot share code with FilePipeInputProc because here we must * use recv to obtain the input from the channel, not read. * * Results: * The number of bytes read is returned or -1 on error. An output * argument contains the POSIX error code on error, or zero if no error * occurred. * * Side effects: * Reads input from the input device of the channel. * *---------------------------------------------------------------------- */ /* ARGSUSED */ static int TcpInputProc( ClientData instanceData, /* Socket state. */ char *buf, /* Where to store data read. */ int bufSize, /* How much space is available in the * buffer? */ int *errorCodePtr) /* Where to store error code. */ { TcpState *statePtr = instanceData; int bytesRead; *errorCodePtr = 0; if (WaitForConnect(statePtr, errorCodePtr) != 0) { return -1; } bytesRead = recv(statePtr->fds.fd, buf, (size_t) bufSize, 0); if (bytesRead > -1) { return bytesRead; } if (errno == ECONNRESET) { /* * Turn ECONNRESET into a soft EOF condition. */ return 0; } *errorCodePtr = errno; return -1; } /* *---------------------------------------------------------------------- * * TcpOutputProc -- * * This function is invoked by the generic IO level to write output to a * TCP socket based channel. * * NOTE: We cannot share code with FilePipeOutputProc because here we * must use send, not write, to get reliable error reporting. * * Results: * The number of bytes written is returned. An output argument is set to * a POSIX error code if an error occurred, or zero. * * Side effects: * Writes output on the output device of the channel. * *---------------------------------------------------------------------- */ static int TcpOutputProc( ClientData instanceData, /* Socket state. */ const char *buf, /* The data buffer. */ int toWrite, /* How many bytes to write? */ int *errorCodePtr) /* Where to store error code. */ { TcpState *statePtr = instanceData; int written; *errorCodePtr = 0; if (WaitForConnect(statePtr, errorCodePtr) != 0) { return -1; } written = send(statePtr->fds.fd, buf, (size_t) toWrite, 0); if (written > -1) { return written; } *errorCodePtr = errno; return -1; } /* *---------------------------------------------------------------------- * * TcpCloseProc -- * * This function is invoked by the generic IO level to perform * channel-type-specific cleanup when a TCP socket based channel is * closed. * * Results: * 0 if successful, the value of errno if failed. * * Side effects: * Closes the socket of the channel. * *---------------------------------------------------------------------- */ /* ARGSUSED */ static int TcpCloseProc( ClientData instanceData, /* The socket to close. */ Tcl_Interp *interp) /* For error reporting - unused. */ { TcpState *statePtr = instanceData; int errorCode = 0; TcpFdList *fds; /* * Delete a file handler that may be active for this socket if this is a * server socket - the file handler was created automatically by Tcl as * part of the mechanism to accept new client connections. Channel * handlers are already deleted in the generic IO channel closing code * that called this function, so we do not have to delete them here. */ for (fds = &statePtr->fds; fds != NULL; fds = fds->next) { if (fds->fd < 0) { continue; } Tcl_DeleteFileHandler(fds->fd); if (close(fds->fd) < 0) { errorCode = errno; } } fds = statePtr->fds.next; while (fds != NULL) { TcpFdList *next = fds->next; ckfree(fds); fds = next; } if (statePtr->addrlist != NULL) { freeaddrinfo(statePtr->addrlist); } if (statePtr->myaddrlist != NULL) { freeaddrinfo(statePtr->myaddrlist); } ckfree(statePtr); return errorCode; } /* *---------------------------------------------------------------------- * * TcpClose2Proc -- * * This function is called by the generic IO level to perform the channel * type specific part of a half-close: namely, a shutdown() on a socket. * * Results: * 0 if successful, the value of errno if failed. * * Side effects: * Shuts down one side of the socket. * *---------------------------------------------------------------------- */ static int TcpClose2Proc( ClientData instanceData, /* The socket to close. */ Tcl_Interp *interp, /* For error reporting. */ int flags) /* Flags that indicate which side to close. */ { TcpState *statePtr = instanceData; int errorCode = 0; int sd; /* * Shutdown the OS socket handle. */ switch(flags) { case TCL_CLOSE_READ: sd = SHUT_RD; break; case TCL_CLOSE_WRITE: sd = SHUT_WR; break; default: if (interp) { Tcl_SetObjResult(interp, Tcl_NewStringObj( "socket close2proc called bidirectionally", -1)); } return TCL_ERROR; } if (shutdown(statePtr->fds.fd,sd) < 0) { errorCode = errno; } return errorCode; } /* *---------------------------------------------------------------------- * * TcpHostPortList -- * * This function is called by the -gethostname and -getpeername * switches of TcpGetOptionProc() to add three list elements * with the textual representation of the given address to the * given DString. * * Results: * None. * * Side effects: * Adds three elements do dsPtr * *---------------------------------------------------------------------- */ static void TcpHostPortList( Tcl_Interp *interp, Tcl_DString *dsPtr, address addr, socklen_t salen) { #define SUPPRESS_RDNS_VAR "::tcl::unsupported::noReverseDNS" char host[NI_MAXHOST], nhost[NI_MAXHOST], nport[NI_MAXSERV]; int flags = 0; getnameinfo(&addr.sa, salen, nhost, sizeof(nhost), nport, sizeof(nport), NI_NUMERICHOST | NI_NUMERICSERV); Tcl_DStringAppendElement(dsPtr, nhost); /* * We don't want to resolve INADDR_ANY and sin6addr_any; they * can sometimes cause problems (and never have a name). */ if (addr.sa.sa_family == AF_INET) { if (addr.sa4.sin_addr.s_addr == INADDR_ANY) { flags |= NI_NUMERICHOST; } #ifndef NEED_FAKE_RFC2553 } else if (addr.sa.sa_family == AF_INET6) { if ((IN6_ARE_ADDR_EQUAL(&addr.sa6.sin6_addr, &in6addr_any)) || (IN6_IS_ADDR_V4MAPPED(&addr.sa6.sin6_addr) && addr.sa6.sin6_addr.s6_addr[12] == 0 && addr.sa6.sin6_addr.s6_addr[13] == 0 && addr.sa6.sin6_addr.s6_addr[14] == 0 && addr.sa6.sin6_addr.s6_addr[15] == 0)) { flags |= NI_NUMERICHOST; } #endif /* NEED_FAKE_RFC2553 */ } /* Check if reverse DNS has been switched off globally */ if (interp != NULL && Tcl_GetVar(interp, SUPPRESS_RDNS_VAR, 0) != NULL) { flags |= NI_NUMERICHOST; } if (getnameinfo(&addr.sa, salen, host, sizeof(host), NULL, 0, flags) == 0) { /* Reverse mapping worked */ Tcl_DStringAppendElement(dsPtr, host); } else { /* Reverse mappong failed - use the numeric rep once more */ Tcl_DStringAppendElement(dsPtr, nhost); } Tcl_DStringAppendElement(dsPtr, nport); } /* *---------------------------------------------------------------------- * * TcpGetOptionProc -- * * Computes an option value for a TCP socket based channel, or a list of * all options and their values. * * Note: This code is based on code contributed by John Haxby. * * Results: * A standard Tcl result. The value of the specified option or a list of * all options and their values is returned in the supplied DString. Sets * Error message if needed. * * Side effects: * None. * *---------------------------------------------------------------------- */ static int TcpGetOptionProc( ClientData instanceData, /* Socket state. */ Tcl_Interp *interp, /* For error reporting - can be NULL. */ const char *optionName, /* Name of the option to retrieve the value * for, or NULL to get all options and their * values. */ Tcl_DString *dsPtr) /* Where to store the computed value; * initialized by caller. */ { TcpState *statePtr = instanceData; size_t len = 0; WaitForConnect(statePtr, NULL); if (optionName != NULL) { len = strlen(optionName); } if ((len > 1) && (optionName[1] == 'e') && (strncmp(optionName, "-error", len) == 0)) { socklen_t optlen = sizeof(int); 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 { 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); } 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; socklen_t size = sizeof(peername); if (getpeername(statePtr->fds.fd, &peername.sa, &size) >= 0) { if (len == 0) { Tcl_DStringAppendElement(dsPtr, "-peername"); Tcl_DStringStartSublist(dsPtr); } TcpHostPortList(interp, dsPtr, peername, size); if (len) { return TCL_OK; } Tcl_DStringEndSublist(dsPtr); } else { /* * getpeername failed - but if we were asked for all the options * (len==0), don't flag an error at that point because it could be * an fconfigure request on a server socket (which have no peer). * Same must be done on win&mac. */ if (len) { if (interp) { Tcl_SetObjResult(interp, Tcl_ObjPrintf( "can't get peername: %s", Tcl_PosixError(interp))); } return TCL_ERROR; } } } if ((len == 0) || ((len > 1) && (optionName[1] == 's') && (strncmp(optionName, "-sockname", len) == 0))) { TcpFdList *fds; address sockname; socklen_t size; int found = 0; if (len == 0) { Tcl_DStringAppendElement(dsPtr, "-sockname"); Tcl_DStringStartSublist(dsPtr); } for (fds = &statePtr->fds; fds != NULL; fds = fds->next) { size = sizeof(sockname); if (getsockname(fds->fd, &(sockname.sa), &size) >= 0) { found = 1; TcpHostPortList(interp, dsPtr, sockname, size); } } if (found) { if (len) { return TCL_OK; } Tcl_DStringEndSublist(dsPtr); } else { if (interp) { Tcl_SetObjResult(interp, Tcl_ObjPrintf( "can't get sockname: %s", Tcl_PosixError(interp))); } return TCL_ERROR; } } if (len > 0) { return Tcl_BadChannelOption(interp, optionName, "peername sockname"); } return TCL_OK; } /* *---------------------------------------------------------------------- * * TcpWatchProc -- * * Initialize the notifier to watch the fd from this channel. * * Results: * None. * * Side effects: * Sets up the notifier so that a future event on the channel will be * seen by Tcl. * *---------------------------------------------------------------------- */ 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 * TCL_READABLE, TCL_WRITABLE and * TCL_EXCEPTION. */ { TcpState *statePtr = instanceData; if (statePtr->acceptProc != NULL) { /* * Make sure we don't mess with server sockets since they will never * be readable or writable at the Tcl level. This keeps Tcl scripts * from interfering with the -accept behavior (bug #3394732). */ return; } 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) { /* * 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); } } /* *---------------------------------------------------------------------- * * TcpGetHandleProc -- * * Called from Tcl_GetChannelHandle to retrieve OS handles from inside a * TCP socket based channel. * * Results: * Returns TCL_OK with the fd in handlePtr, or TCL_ERROR if there is no * handle for the specified direction. * * Side effects: * None. * *---------------------------------------------------------------------- */ /* ARGSUSED */ static int TcpGetHandleProc( ClientData instanceData, /* The socket state. */ int direction, /* Not used. */ ClientData *handlePtr) /* Where to store the handle. */ { TcpState *statePtr = instanceData; *handlePtr = INT2PTR(statePtr->fds.fd); return TCL_OK; } /* *---------------------------------------------------------------------- * * TcpAsyncCallback -- * * 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. * *---------------------------------------------------------------------- */ static void TcpAsyncCallback( ClientData clientData, /* The socket state. */ int mask) /* Events of interest; an OR-ed combination of * TCL_READABLE, TCL_WRITABLE and * TCL_EXCEPTION. */ { TcpConnect(NULL, clientData); } /* *---------------------------------------------------------------------- * * TcpConnect -- * * This function opens a new socket in client mode. * * Results: * TCL_OK, if the socket was successfully connected or an asynchronous * connection is in progress. If an error occurs, TCL_ERROR is returned * and an error message is left in interp. * * Side effects: * Opens a socket. * * Remarks: * A single host name may resolve to more than one IP address, e.g. for * an IPv4/IPv6 dual stack host. For handling asyncronously connecting * sockets in the background for such hosts, this function can act as a * coroutine. On the first call, it sets up the control variables for the * two nested loops over the local and remote addresses. Once the first * connection attempt is in progress, it sets up itself as a writable * event handler for that socket, and returns. When the callback occurs, * control is transferred to the "reenter" label, right after the initial * return and the loops resume as if they had never been interrupted. * For syncronously connecting sockets, the loops work the usual way. * *---------------------------------------------------------------------- */ static int TcpConnect( Tcl_Interp *interp, /* For error reporting; can be NULL. */ TcpState *statePtr) { socklen_t optlen; 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 (statePtr->addr = statePtr->addrlist; statePtr->addr != NULL; statePtr->addr = statePtr->addr->ai_next) { 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 (statePtr->myaddr->ai_family != statePtr->addr->ai_family) { continue; } /* * Close the socket if it is still open from the last unsuccessful * iteration. */ if (statePtr->fds.fd >= 0) { close(statePtr->fds.fd); statePtr->fds.fd = -1; errno = 0; } statePtr->fds.fd = socket(statePtr->addr->ai_family, SOCK_STREAM, 0); if (statePtr->fds.fd < 0) { continue; } /* * Set the close-on-exec flag so that the socket will not get * inherited by child processes. */ fcntl(statePtr->fds.fd, F_SETFD, FD_CLOEXEC); /* * Set kernel space buffering */ TclSockMinimumBuffers(INT2PTR(statePtr->fds.fd), SOCKET_BUFSIZE); if (async) { ret = TclUnixSetBlockingMode(statePtr->fds.fd,TCL_MODE_NONBLOCKING); if (ret < 0) { continue; } } /* 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)); ret = bind(statePtr->fds.fd, statePtr->myaddr->ai_addr, statePtr->myaddr->ai_addrlen); if (ret < 0) { error = errno; continue; } /* * Attempt to connect. The connect may fail at present with an * EINPROGRESS but at a later time it will complete. The caller * will set up a file handler on the socket if she is interested * in being informed when the connect completes. */ 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: CLEAR_BITS(statePtr->flags, TCP_ASYNC_PENDING); Tcl_DeleteFileHandler(statePtr->fds.fd); /* * Read the error state from the socket to see if the async * connection has succeeded or failed. As this clears the * error condition, we cache the status in the socket state * struct for later retrieval by [fconfigure -error]. */ optlen = sizeof(int); getsockopt(statePtr->fds.fd, SOL_SOCKET, SO_ERROR, (char *) &error, &optlen); errno = error; } if (error == 0) { goto out; } } } out: statePtr->connectError = error; CLEAR_BITS(statePtr->flags, TCP_ASYNC_CONNECT); if (async_callback) { /* * An asynchonous connection has finally succeeded or failed. */ 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 * upon reading of getsockopt(SO_ERROR), at least some OSes clear the * writable state from the socket, and so a subsequent select() on * behalf of a script level [fileevent] would not fire. It doesn't * hurt that this is also called in the successful case and will save * the event mechanism one roundtrip through select(). */ 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 * invalid -myaddr was given. */ if (interp != NULL) { errno = error; Tcl_SetObjResult(interp, Tcl_ObjPrintf( "couldn't open socket: %s", Tcl_PosixError(interp))); } return TCL_ERROR; } return TCL_OK; } /* *---------------------------------------------------------------------- * * Tcl_OpenTcpClient -- * * Opens a TCP client socket and creates a channel around it. * * Results: * The channel or NULL if failed. An error message is returned in the * interpreter on failure. * * Side effects: * Opens a client socket and creates a new channel. * *---------------------------------------------------------------------- */ Tcl_Channel Tcl_OpenTcpClient( Tcl_Interp *interp, /* For error reporting; can be NULL. */ int port, /* Port number to open. */ const char *host, /* Host on which to open port. */ const char *myaddr, /* Client-side address */ int myport, /* Client-side port */ int async) /* If nonzero, attempt to do an asynchronous * connect. Otherwise we do a blocking * connect. */ { TcpState *statePtr; const char *errorMsg = NULL; struct addrinfo *addrlist = NULL, *myaddrlist = NULL; char channelName[SOCK_CHAN_LENGTH]; /* * Do the name lookups for the local and remote addresses. */ if (!TclCreateSocketAddress(interp, &addrlist, host, port, 0, &errorMsg) || !TclCreateSocketAddress(interp, &myaddrlist, myaddr, myport, 1, &errorMsg)) { if (addrlist != NULL) { freeaddrinfo(addrlist); } if (interp != NULL) { Tcl_SetObjResult(interp, Tcl_ObjPrintf( "couldn't open socket: %s", errorMsg)); } return NULL; } /* * Allocate a new TcpState for this socket. */ 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 (TcpConnect(interp, statePtr) != TCL_OK) { TcpCloseProc(statePtr, NULL); return NULL; } sprintf(channelName, SOCK_TEMPLATE, (long) statePtr); statePtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName, statePtr, (TCL_READABLE | TCL_WRITABLE)); if (Tcl_SetChannelOption(interp, statePtr->channel, "-translation", "auto crlf") == TCL_ERROR) { Tcl_Close(NULL, statePtr->channel); return NULL; } return statePtr->channel; } /* *---------------------------------------------------------------------- * * Tcl_MakeTcpClientChannel -- * * Creates a Tcl_Channel from an existing client TCP socket. * * Results: * The Tcl_Channel wrapped around the preexisting TCP socket. * * Side effects: * None. * *---------------------------------------------------------------------- */ Tcl_Channel Tcl_MakeTcpClientChannel( ClientData sock) /* The socket to wrap up into a channel. */ { return (Tcl_Channel) TclpMakeTcpClientChannelMode(sock, (TCL_READABLE | TCL_WRITABLE)); } /* *---------------------------------------------------------------------- * * TclpMakeTcpClientChannelMode -- * * Creates a Tcl_Channel from an existing client TCP socket * with given mode. * * Results: * The Tcl_Channel wrapped around the preexisting TCP socket. * * Side effects: * None. * *---------------------------------------------------------------------- */ void * TclpMakeTcpClientChannelMode( void *sock, /* The socket to wrap up into a channel. */ int mode) /* ORed combination of TCL_READABLE and * TCL_WRITABLE to indicate file mode. */ { TcpState *statePtr; char channelName[SOCK_CHAN_LENGTH]; statePtr = ckalloc(sizeof(TcpState)); memset(statePtr, 0, sizeof(TcpState)); statePtr->fds.fd = PTR2INT(sock); statePtr->flags = 0; sprintf(channelName, SOCK_TEMPLATE, (long)statePtr); statePtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName, statePtr, mode); if (Tcl_SetChannelOption(NULL, statePtr->channel, "-translation", "auto crlf") == TCL_ERROR) { Tcl_Close(NULL, statePtr->channel); return NULL; } return statePtr->channel; } /* *---------------------------------------------------------------------- * * Tcl_OpenTcpServer -- * * Opens a TCP server socket and creates a channel around it. * * Results: * The channel or NULL if failed. If an error occurred, an error message * is left in the interp's result if interp is not NULL. * * Side effects: * Opens a server socket and creates a new channel. * *---------------------------------------------------------------------- */ Tcl_Channel Tcl_OpenTcpServer( Tcl_Interp *interp, /* For error reporting - may be NULL. */ int port, /* Port number to open. */ const char *myHost, /* Name of local host. */ Tcl_TcpAcceptProc *acceptProc, /* Callback for accepting connections from new * clients. */ ClientData acceptProcData) /* Data for the callback. */ { int status = 0, sock = -1, reuseaddr = 1, chosenport = 0; struct addrinfo *addrlist = NULL, *addrPtr; /* socket address */ TcpState *statePtr = NULL; char channelName[SOCK_CHAN_LENGTH]; const char *errorMsg = NULL; TcpFdList *fds = NULL, *newfds; /* * Try to record and return the most meaningful error message, i.e. the * one from the first socket that went the farthest before it failed. */ enum { LOOKUP, SOCKET, BIND, LISTEN } howfar = LOOKUP; int my_errno = 0; if (!TclCreateSocketAddress(interp, &addrlist, myHost, port, 1, &errorMsg)) { my_errno = errno; goto error; } for (addrPtr = addrlist; addrPtr != NULL; addrPtr = addrPtr->ai_next) { sock = socket(addrPtr->ai_family, addrPtr->ai_socktype, addrPtr->ai_protocol); if (sock == -1) { if (howfar < SOCKET) { howfar = SOCKET; my_errno = errno; } continue; } /* * Set the close-on-exec flag so that the socket will not get * inherited by child processes. */ fcntl(sock, F_SETFD, FD_CLOEXEC); /* * Set kernel space buffering */ TclSockMinimumBuffers(INT2PTR(sock), SOCKET_BUFSIZE); /* * Set up to reuse server addresses automatically and bind to the * specified port. */ (void) setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *) &reuseaddr, sizeof(reuseaddr)); /* * Make sure we use the same port number when opening two server * sockets for IPv4 and IPv6 on a random port. * * As sockaddr_in6 uses the same offset and size for the port member * as sockaddr_in, we can handle both through the IPv4 API. */ if (port == 0 && chosenport != 0) { ((struct sockaddr_in *) addrPtr->ai_addr)->sin_port = htons(chosenport); } #ifdef IPV6_V6ONLY /* Missing on: Solaris 2.8 */ if (addrPtr->ai_family == AF_INET6) { int v6only = 1; (void) setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &v6only, sizeof(v6only)); } #endif /* IPV6_V6ONLY */ status = bind(sock, addrPtr->ai_addr, addrPtr->ai_addrlen); if (status == -1) { if (howfar < BIND) { howfar = BIND; my_errno = errno; } close(sock); sock = -1; continue; } if (port == 0 && chosenport == 0) { address sockname; socklen_t namelen = sizeof(sockname); /* * Synchronize port numbers when binding to port 0 of multiple * addresses. */ if (getsockname(sock, &sockname.sa, &namelen) >= 0) { chosenport = ntohs(sockname.sa4.sin_port); } } status = listen(sock, SOMAXCONN); if (status < 0) { if (howfar < LISTEN) { howfar = LISTEN; my_errno = errno; } close(sock); sock = -1; continue; } if (statePtr == NULL) { /* * Allocate a new TcpState for this socket. */ statePtr = ckalloc(sizeof(TcpState)); memset(statePtr, 0, sizeof(TcpState)); statePtr->acceptProc = acceptProc; statePtr->acceptProcData = acceptProcData; sprintf(channelName, SOCK_TEMPLATE, (long) statePtr); newfds = &statePtr->fds; } else { newfds = ckalloc(sizeof(TcpFdList)); memset(newfds, (int) 0, sizeof(TcpFdList)); fds->next = newfds; } newfds->fd = sock; newfds->statePtr = statePtr; fds = newfds; /* * Set up the callback mechanism for accepting connections from new * clients. */ Tcl_CreateFileHandler(sock, TCL_READABLE, TcpAccept, fds); } error: if (addrlist != NULL) { freeaddrinfo(addrlist); } if (statePtr != NULL) { statePtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName, statePtr, 0); return statePtr->channel; } if (interp != NULL) { Tcl_Obj *errorObj = Tcl_NewStringObj("couldn't open socket: ", -1); if (errorMsg == NULL) { errno = my_errno; Tcl_AppendToObj(errorObj, Tcl_PosixError(interp), -1); } else { Tcl_AppendToObj(errorObj, errorMsg, -1); } Tcl_SetObjResult(interp, errorObj); } if (sock != -1) { close(sock); } return NULL; } /* *---------------------------------------------------------------------- * * TcpAccept -- * Accept a TCP socket connection. This is called by the event loop. * * Results: * None. * * Side effects: * Creates a new connection socket. Calls the registered callback for the * connection acceptance mechanism. * *---------------------------------------------------------------------- */ /* ARGSUSED */ static void TcpAccept( ClientData data, /* Callback token. */ int mask) /* Not used. */ { TcpFdList *fds = data; /* Client data of server socket. */ int newsock; /* The new client socket */ TcpState *newSockState; /* State for new socket. */ address addr; /* The remote address */ socklen_t len; /* For accept interface */ char channelName[SOCK_CHAN_LENGTH]; char host[NI_MAXHOST], port[NI_MAXSERV]; len = sizeof(addr); newsock = accept(fds->fd, &addr.sa, &len); if (newsock < 0) { return; } /* * Set close-on-exec flag to prevent the newly accepted socket from being * inherited by child processes. */ (void) fcntl(newsock, F_SETFD, FD_CLOEXEC); newSockState = ckalloc(sizeof(TcpState)); memset(newSockState, 0, sizeof(TcpState)); newSockState->flags = 0; newSockState->fds.fd = newsock; sprintf(channelName, SOCK_TEMPLATE, (long) newSockState); newSockState->channel = Tcl_CreateChannel(&tcpChannelType, channelName, newSockState, (TCL_READABLE | TCL_WRITABLE)); Tcl_SetChannelOption(NULL, newSockState->channel, "-translation", "auto crlf"); if (fds->statePtr->acceptProc != NULL) { getnameinfo(&addr.sa, len, host, sizeof(host), port, sizeof(port), NI_NUMERICHOST|NI_NUMERICSERV); fds->statePtr->acceptProc(fds->statePtr->acceptProcData, newSockState->channel, host, atoi(port)); } } /* * Local Variables: * mode: c * c-basic-offset: 4 * fill-column: 78 * tab-width: 8 * indent-tabs-mode: nil * End: */