diff options
Diffstat (limited to 'unix/tclUnixSock.c')
| -rw-r--r-- | unix/tclUnixSock.c | 1496 |
1 files changed, 1487 insertions, 9 deletions
diff --git a/unix/tclUnixSock.c b/unix/tclUnixSock.c index a2b4015..ca8d677 100644 --- a/unix/tclUnixSock.c +++ b/unix/tclUnixSock.c @@ -12,14 +12,180 @@ #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. */ + 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 */ + +/* + * 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 /* *---------------------------------------------------------------------- * @@ -40,7 +206,7 @@ InitializeHostName( int *lengthPtr, Tcl_Encoding *encodingPtr) { - CONST char *native = NULL; + const char *native = NULL; #ifndef NO_UNAME struct utsname u; @@ -59,7 +225,7 @@ InitializeHostName( char *dot = strchr(u.nodename, '.'); if (dot != NULL) { - char *node = ckalloc((unsigned) (dot - u.nodename + 1)); + char *node = ckalloc(dot - u.nodename + 1); memcpy(node, u.nodename, (size_t) (dot - u.nodename)); node[dot - u.nodename] = '\0'; @@ -76,7 +242,7 @@ InitializeHostName( if (native == NULL) { native = tclEmptyStringRep; } -#else +#else /* !NO_UNAME */ /* * Uname doesn't exist; try gethostname instead. * @@ -92,7 +258,7 @@ InitializeHostName( * Fix suggested by Viktor Dukhovni (viktor@esm.com) */ -# if defined(SYS_NMLN) && SYS_NMLEN >= 256 +# if defined(SYS_NMLN) && (SYS_NMLEN >= 256) char buffer[SYS_NMLEN]; # else char buffer[256]; @@ -101,12 +267,12 @@ InitializeHostName( if (gethostname(buffer, sizeof(buffer)) > -1) { /* INTL: Native. */ native = buffer; } -#endif +#endif /* NO_UNAME */ *encodingPtr = Tcl_GetEncoding(NULL, NULL); *lengthPtr = strlen(native); - *valuePtr = ckalloc((unsigned int) (*lengthPtr)+1); - memcpy(*valuePtr, (void *) native, (size_t)(*lengthPtr)+1); + *valuePtr = ckalloc((*lengthPtr) + 1); + memcpy(*valuePtr, native, (size_t)(*lengthPtr)+1); } /* @@ -127,7 +293,7 @@ InitializeHostName( *---------------------------------------------------------------------- */ -CONST char * +const char * Tcl_GetHostName(void) { return Tcl_GetString(TclGetProcessGlobalValue(&hostName)); @@ -179,9 +345,1321 @@ TclpFinalizeSockets(void) } /* + *---------------------------------------------------------------------- + * + * 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; + } + + 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 ( (statePtr->flags & TCP_ASYNC_CONNECT) ) { + /* + * In async connect output an empty string + */ + if (len == 0) { + Tcl_DStringAppendElement(dsPtr, "-peername"); + Tcl_DStringAppendElement(dsPtr, ""); + } else { + return TCL_OK; + } + } else if (getpeername(statePtr->fds.fd, &peername.sa, &size) >= 0) { + /* + * Peername fetch succeeded - output list + */ + 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); + } + if ( (statePtr->flags & TCP_ASYNC_CONNECT) ) { + /* + * In async connect output an empty string + */ + found = 1; + } else { + 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, "connecting 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 = EHOSTUNREACH; + 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: */ |