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Diffstat (limited to '')
| -rw-r--r-- | src/connection.h | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/src/connection.h b/src/connection.h new file mode 100644 index 0000000..dad2e2f --- /dev/null +++ b/src/connection.h @@ -0,0 +1,258 @@ + +/* + * Copyright (c) 2019, Redis Labs + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * * Neither the name of Redis nor the names of its contributors may be used + * to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef __REDIS_CONNECTION_H +#define __REDIS_CONNECTION_H + +#include <errno.h> +#include <sys/uio.h> + +#define CONN_INFO_LEN 32 + +struct aeEventLoop; +typedef struct connection connection; + +typedef enum { + CONN_STATE_NONE = 0, + CONN_STATE_CONNECTING, + CONN_STATE_ACCEPTING, + CONN_STATE_CONNECTED, + CONN_STATE_CLOSED, + CONN_STATE_ERROR +} ConnectionState; + +#define CONN_FLAG_CLOSE_SCHEDULED (1<<0) /* Closed scheduled by a handler */ +#define CONN_FLAG_WRITE_BARRIER (1<<1) /* Write barrier requested */ + +#define CONN_TYPE_SOCKET 1 +#define CONN_TYPE_TLS 2 + +typedef void (*ConnectionCallbackFunc)(struct connection *conn); + +typedef struct ConnectionType { + void (*ae_handler)(struct aeEventLoop *el, int fd, void *clientData, int mask); + int (*connect)(struct connection *conn, const char *addr, int port, const char *source_addr, ConnectionCallbackFunc connect_handler); + int (*write)(struct connection *conn, const void *data, size_t data_len); + int (*writev)(struct connection *conn, const struct iovec *iov, int iovcnt); + int (*read)(struct connection *conn, void *buf, size_t buf_len); + void (*close)(struct connection *conn); + int (*accept)(struct connection *conn, ConnectionCallbackFunc accept_handler); + int (*set_write_handler)(struct connection *conn, ConnectionCallbackFunc handler, int barrier); + int (*set_read_handler)(struct connection *conn, ConnectionCallbackFunc handler); + const char *(*get_last_error)(struct connection *conn); + int (*blocking_connect)(struct connection *conn, const char *addr, int port, long long timeout); + ssize_t (*sync_write)(struct connection *conn, char *ptr, ssize_t size, long long timeout); + ssize_t (*sync_read)(struct connection *conn, char *ptr, ssize_t size, long long timeout); + ssize_t (*sync_readline)(struct connection *conn, char *ptr, ssize_t size, long long timeout); + int (*get_type)(struct connection *conn); +} ConnectionType; + +struct connection { + ConnectionType *type; + ConnectionState state; + short int flags; + short int refs; + int last_errno; + void *private_data; + ConnectionCallbackFunc conn_handler; + ConnectionCallbackFunc write_handler; + ConnectionCallbackFunc read_handler; + int fd; +}; + +/* The connection module does not deal with listening and accepting sockets, + * so we assume we have a socket when an incoming connection is created. + * + * The fd supplied should therefore be associated with an already accept()ed + * socket. + * + * connAccept() may directly call accept_handler(), or return and call it + * at a later time. This behavior is a bit awkward but aims to reduce the need + * to wait for the next event loop, if no additional handshake is required. + * + * IMPORTANT: accept_handler may decide to close the connection, calling connClose(). + * To make this safe, the connection is only marked with CONN_FLAG_CLOSE_SCHEDULED + * in this case, and connAccept() returns with an error. + * + * connAccept() callers must always check the return value and on error (C_ERR) + * a connClose() must be called. + */ + +static inline int connAccept(connection *conn, ConnectionCallbackFunc accept_handler) { + return conn->type->accept(conn, accept_handler); +} + +/* Establish a connection. The connect_handler will be called when the connection + * is established, or if an error has occurred. + * + * The connection handler will be responsible to set up any read/write handlers + * as needed. + * + * If C_ERR is returned, the operation failed and the connection handler shall + * not be expected. + */ +static inline int connConnect(connection *conn, const char *addr, int port, const char *src_addr, + ConnectionCallbackFunc connect_handler) { + return conn->type->connect(conn, addr, port, src_addr, connect_handler); +} + +/* Blocking connect. + * + * NOTE: This is implemented in order to simplify the transition to the abstract + * connections, but should probably be refactored out of cluster.c and replication.c, + * in favor of a pure async implementation. + */ +static inline int connBlockingConnect(connection *conn, const char *addr, int port, long long timeout) { + return conn->type->blocking_connect(conn, addr, port, timeout); +} + +/* Write to connection, behaves the same as write(2). + * + * Like write(2), a short write is possible. A -1 return indicates an error. + * + * The caller should NOT rely on errno. Testing for an EAGAIN-like condition, use + * connGetState() to see if the connection state is still CONN_STATE_CONNECTED. + */ +static inline int connWrite(connection *conn, const void *data, size_t data_len) { + return conn->type->write(conn, data, data_len); +} + +/* Gather output data from the iovcnt buffers specified by the members of the iov + * array: iov[0], iov[1], ..., iov[iovcnt-1] and write to connection, behaves the same as writev(3). + * + * Like writev(3), a short write is possible. A -1 return indicates an error. + * + * The caller should NOT rely on errno. Testing for an EAGAIN-like condition, use + * connGetState() to see if the connection state is still CONN_STATE_CONNECTED. + */ +static inline int connWritev(connection *conn, const struct iovec *iov, int iovcnt) { + return conn->type->writev(conn, iov, iovcnt); +} + +/* Read from the connection, behaves the same as read(2). + * + * Like read(2), a short read is possible. A return value of 0 will indicate the + * connection was closed, and -1 will indicate an error. + * + * The caller should NOT rely on errno. Testing for an EAGAIN-like condition, use + * connGetState() to see if the connection state is still CONN_STATE_CONNECTED. + */ +static inline int connRead(connection *conn, void *buf, size_t buf_len) { + int ret = conn->type->read(conn, buf, buf_len); + return ret; +} + +/* Register a write handler, to be called when the connection is writable. + * If NULL, the existing handler is removed. + */ +static inline int connSetWriteHandler(connection *conn, ConnectionCallbackFunc func) { + return conn->type->set_write_handler(conn, func, 0); +} + +/* Register a read handler, to be called when the connection is readable. + * If NULL, the existing handler is removed. + */ +static inline int connSetReadHandler(connection *conn, ConnectionCallbackFunc func) { + return conn->type->set_read_handler(conn, func); +} + +/* Set a write handler, and possibly enable a write barrier, this flag is + * cleared when write handler is changed or removed. + * With barrier enabled, we never fire the event if the read handler already + * fired in the same event loop iteration. Useful when you want to persist + * things to disk before sending replies, and want to do that in a group fashion. */ +static inline int connSetWriteHandlerWithBarrier(connection *conn, ConnectionCallbackFunc func, int barrier) { + return conn->type->set_write_handler(conn, func, barrier); +} + +static inline void connClose(connection *conn) { + conn->type->close(conn); +} + +/* Returns the last error encountered by the connection, as a string. If no error, + * a NULL is returned. + */ +static inline const char *connGetLastError(connection *conn) { + return conn->type->get_last_error(conn); +} + +static inline ssize_t connSyncWrite(connection *conn, char *ptr, ssize_t size, long long timeout) { + return conn->type->sync_write(conn, ptr, size, timeout); +} + +static inline ssize_t connSyncRead(connection *conn, char *ptr, ssize_t size, long long timeout) { + return conn->type->sync_read(conn, ptr, size, timeout); +} + +static inline ssize_t connSyncReadLine(connection *conn, char *ptr, ssize_t size, long long timeout) { + return conn->type->sync_readline(conn, ptr, size, timeout); +} + +/* Return CONN_TYPE_* for the specified connection */ +static inline int connGetType(connection *conn) { + return conn->type->get_type(conn); +} + +static inline int connLastErrorRetryable(connection *conn) { + return conn->last_errno == EINTR; +} + +connection *connCreateSocket(); +connection *connCreateAcceptedSocket(int fd); + +connection *connCreateTLS(); +connection *connCreateAcceptedTLS(int fd, int require_auth); + +void connSetPrivateData(connection *conn, void *data); +void *connGetPrivateData(connection *conn); +int connGetState(connection *conn); +int connHasWriteHandler(connection *conn); +int connHasReadHandler(connection *conn); +int connGetSocketError(connection *conn); + +/* anet-style wrappers to conns */ +int connBlock(connection *conn); +int connNonBlock(connection *conn); +int connEnableTcpNoDelay(connection *conn); +int connDisableTcpNoDelay(connection *conn); +int connKeepAlive(connection *conn, int interval); +int connSendTimeout(connection *conn, long long ms); +int connRecvTimeout(connection *conn, long long ms); +int connPeerToString(connection *conn, char *ip, size_t ip_len, int *port); +int connFormatFdAddr(connection *conn, char *buf, size_t buf_len, int fd_to_str_type); +int connSockName(connection *conn, char *ip, size_t ip_len, int *port); +const char *connGetInfo(connection *conn, char *buf, size_t buf_len); + +/* Helpers for tls special considerations */ +sds connTLSGetPeerCert(connection *conn); +int tlsHasPendingData(); +int tlsProcessPendingData(); + +#endif /* __REDIS_CONNECTION_H */ |