2 * Copyright (C) 2015 Red Hat, Inc.
4 * This file is part of the device-mapper multipath userspace tools.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public License
8 * as published by the Free Software Foundation; either version 2.1
9 * of the License, or (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #ifndef LIB_MPATH_CMD_H
21 #define LIB_MPATH_CMD_H
24 * This should be sufficient for json output for >10000 maps,
27 #define MAX_REPLY_LEN (32 * 1024 * 1024)
33 #define DEFAULT_SOCKET "/org/kernel/linux/storage/multipathd"
34 #define DEFAULT_REPLY_TIMEOUT 4000
39 * Same as mpath_connect() (see below) except for the "nonblocking"
41 * If "nonblocking" is set, connects in non-blocking mode. This is
42 * useful to avoid blocking if the listening socket's backlog is
43 * exceeded. In this case, errno will be set to EAGAIN.
44 * In case of success, the returned file descriptor is in in blocking
45 * mode, even if "nonblocking" was true.
48 * A file descriptor on success. -1 on failure (with errno set).
50 int __mpath_connect(int nonblocking);
54 * Connect to the running multipathd daemon. On systems with the
55 * multipathd.socket systemd unit file installed, this command will
56 * start multipathd if it is not already running. This function
57 * must be run before any of the others in this library
60 * A file descriptor on success. -1 on failure (with errno set).
62 int mpath_connect(void);
67 * Disconnect from the multipathd daemon. This function must be
68 * run after processing all the multipath commands.
71 * 0 on success. -1 on failure (with errno set).
73 int mpath_disconnect(int fd);
78 * Send multipathd a command and return the reply. This function
79 * does the same as calling mpath_send_cmd() and then
83 * 0 on success, and reply will either be NULL (if there was no
84 * reply data), or point to the reply string, which must be freed by
85 * the caller. -1 on failure (with errno set).
87 int mpath_process_cmd(int fd, const char *cmd, char **reply,
88 unsigned int timeout);
93 * Send a command to multipathd
96 * 0 on success. -1 on failure (with errno set)
98 int mpath_send_cmd(int fd, const char *cmd);
103 * Return a reply from multipathd for a previously sent command.
104 * This is equivalent to calling mpath_recv_reply_len(), allocating
105 * a buffer of the appropriate size, and then calling
106 * mpath_recv_reply_data() with that buffer.
109 * 0 on success, and reply will either be NULL (if there was no
110 * reply data), or point to the reply string, which must be freed by
111 * the caller, -1 on failure (with errno set).
113 int mpath_recv_reply(int fd, char **reply, unsigned int timeout);
118 * Return the size of the upcoming reply data from the sent multipath
119 * command. This must be called before calling mpath_recv_reply_data().
122 * The required size of the reply data buffer on success. -1 on
123 * failure (with errno set).
125 ssize_t mpath_recv_reply_len(int fd, unsigned int timeout);
130 * Return the reply data from the sent multipath command.
131 * mpath_recv_reply_len must be called first. reply must point to a
132 * buffer of len size.
135 * 0 on success, and reply will contain the reply data string. -1
136 * on failure (with errno set).
138 int mpath_recv_reply_data(int fd, char *reply, size_t len,
139 unsigned int timeout);
144 #endif /* LIB_MPATH_CMD_H */