View file File name : mpath_cmd.h Content :/* * Copyright (C) 2015 Red Hat, Inc. * * This file is part of the device-mapper multipath userspace tools. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 2.1 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #ifndef LIB_MPATH_CMD_H #define LIB_MPATH_CMD_H /* * This should be sufficient for json output for >10000 maps, * and >60000 paths. */ #define MAX_REPLY_LEN (32 * 1024 * 1024) #ifdef __cplusplus extern "C" { #endif #define DEFAULT_SOCKET "/org/kernel/linux/storage/multipathd" #define DEFAULT_REPLY_TIMEOUT 4000 /* * DESCRIPTION: * Same as mpath_connect() (see below) except for the "nonblocking" * parameter. * If "nonblocking" is set, connects in non-blocking mode. This is * useful to avoid blocking if the listening socket's backlog is * exceeded. In this case, errno will be set to EAGAIN. * In case of success, the returned file descriptor is in in blocking * mode, even if "nonblocking" was true. * * RETURNS: * A file descriptor on success. -1 on failure (with errno set). */ int __mpath_connect(int nonblocking); /* * DESCRIPTION: * Connect to the running multipathd daemon. On systems with the * multipathd.socket systemd unit file installed, this command will * start multipathd if it is not already running. This function * must be run before any of the others in this library * * RETURNS: * A file descriptor on success. -1 on failure (with errno set). */ int mpath_connect(void); /* * DESCRIPTION: * Disconnect from the multipathd daemon. This function must be * run after after processing all the multipath commands. * * RETURNS: * 0 on success. -1 on failure (with errno set). */ int mpath_disconnect(int fd); /* * DESCRIPTION * Send multipathd a command and return the reply. This function * does the same as calling mpath_send_cmd() and then * mpath_recv_reply() * * RETURNS: * 0 on successs, and reply will either be NULL (if there was no * reply data), or point to the reply string, which must be freed by * the caller. -1 on failure (with errno set). */ int mpath_process_cmd(int fd, const char *cmd, char **reply, unsigned int timeout); /* * DESCRIPTION: * Send a command to multipathd * * RETURNS: * 0 on success. -1 on failure (with errno set) */ int mpath_send_cmd(int fd, const char *cmd); /* * DESCRIPTION: * Return a reply from multipathd for a previously sent command. * This is equivalent to calling mpath_recv_reply_len(), allocating * a buffer of the appropriate size, and then calling * mpath_recv_reply_data() with that buffer. * * RETURNS: * 0 on success, and reply will either be NULL (if there was no * reply data), or point to the reply string, which must be freed by * the caller, -1 on failure (with errno set). */ int mpath_recv_reply(int fd, char **reply, unsigned int timeout); /* * DESCRIPTION: * Return the size of the upcoming reply data from the sent multipath * command. This must be called before calling mpath_recv_reply_data(). * * RETURNS: * The required size of the reply data buffer on success. -1 on * failure (with errno set). */ ssize_t mpath_recv_reply_len(int fd, unsigned int timeout); /* * DESCRIPTION: * Return the reply data from the sent multipath command. * mpath_recv_reply_len must be called first. reply must point to a * buffer of len size. * * RETURNS: * 0 on success, and reply will contain the reply data string. -1 * on failure (with errno set). */ int mpath_recv_reply_data(int fd, char *reply, size_t len, unsigned int timeout); #ifdef __cplusplus } #endif #endif /* LIB_MPATH_CMD_H */