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/*
* Copyright (C) 2006-2009 Red Hat, Inc.
*
* Author: Steven Dake <sdake@redhat.com>,
* Angus Salkeld <asalkeld@redhat.com>
*
* This file is part of libqb.
*
* libqb 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.
*
* libqb 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 libqb. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef QB_IPCS_H_DEFINED
#define QB_IPCS_H_DEFINED
/* *INDENT-OFF* */
#ifdef __cplusplus
extern "C" {
#endif
/* *INDENT-ON* */
#include <sys/types.h> /* size_t, ssize_t */
#include <sys/uio.h> /* iovec */
#include <qb/qbipc_common.h> /* qb_ipc_type */
#include <qb/qbloop.h> /* qb_loop_priority */
/**
* @file qbipcs.h
*
* Server IPC API.
*
* @example ipcserver.c
*/
/**
* Rates to be passed to #qb_ipcs_request_rate_limit. The exact interpretation
* depends on how the event loop implementation understands the concept of
* priorities, see the discussion at #qb_ipcs_poll_handlers structure -- an
* integration point between IPC server instance and the underlying event loop.
*/
enum qb_ipcs_rate_limit {
QB_IPCS_RATE_FAST,
QB_IPCS_RATE_NORMAL,
QB_IPCS_RATE_SLOW,
QB_IPCS_RATE_OFF,
QB_IPCS_RATE_OFF_2,
};
struct qb_ipcs_connection;
typedef struct qb_ipcs_connection qb_ipcs_connection_t;
struct qb_ipcs_service;
typedef struct qb_ipcs_service qb_ipcs_service_t;
struct qb_ipcs_stats {
uint32_t active_connections;
uint32_t closed_connections;
};
struct qb_ipcs_connection_stats {
int32_t client_pid;
uint64_t requests;
uint64_t responses;
uint64_t events;
uint64_t send_retries;
uint64_t recv_retries;
int32_t flow_control_state;
uint64_t flow_control_count;
};
struct qb_ipcs_connection_stats_2 {
int32_t client_pid;
uint64_t requests;
uint64_t responses;
uint64_t events;
uint64_t send_retries;
uint64_t recv_retries;
int32_t flow_control_state;
uint64_t flow_control_count;
uint32_t event_q_length;
};
typedef int32_t (*qb_ipcs_dispatch_fn_t) (int32_t fd, int32_t revents,
void *data);
typedef int32_t (*qb_ipcs_dispatch_add_fn)(enum qb_loop_priority p,
int32_t fd,
int32_t events,
void *data,
qb_ipcs_dispatch_fn_t fn);
typedef int32_t (*qb_ipcs_dispatch_mod_fn)(enum qb_loop_priority p,
int32_t fd,
int32_t events,
void *data,
qb_ipcs_dispatch_fn_t fn);
typedef int32_t (*qb_ipcs_dispatch_del_fn)(int32_t fd);
typedef int32_t (*qb_ipcs_job_add_fn)(enum qb_loop_priority p,
void *data,
qb_loop_job_dispatch_fn dispatch_fn);
/**
* A set of callbacks that need to be provided (only #job_add can be #NULL)
* whenever the IPC server is to be run (by the means of #qb_ipcs_run).
* It is possible to use accordingly named functions defined in qbloop.h module
* or integrate with other existing (like GLib's event loop) or entirely new
* code -- see the subtle distinction amongst the possible event loops pointed
* out in the introductory comment at qbloop.h.
*
* At that occasion, please note the correlation of #QB_IPCS_RATE_FAST etc.
* symbolic names with said advisory effect of the priorities in the native
* implementation. This correspondence will not be this intuitively seemless
* if some other event loop implementation is hooked in given that it abids
* them strictly as mentioned (e.g. GLib's event loop over poll'able sources).
* Differences between the two paradigms should also be accounted for when
* the requirement to swap the event loop implementations arises.
*/
struct qb_ipcs_poll_handlers {
qb_ipcs_job_add_fn job_add;
qb_ipcs_dispatch_add_fn dispatch_add;
qb_ipcs_dispatch_mod_fn dispatch_mod;
qb_ipcs_dispatch_del_fn dispatch_del;
};
/**
* This callback is to check whether you want to accept a new connection.
*
* The type of checks you should do are authentication, service availability
* or process resource constraints.
* @return 0 to accept or -errno to indicate a failure (sent back to the client)
*
* @note If connection state data is allocated as a result of this callback
* being invoked, that data must be freed in the destroy callback. Just because
* the accept callback returns 0, that does not guarantee the
* create and closed callback functions will follow.
* @note you can call qb_ipcs_connection_auth_set() within this function.
*/
typedef int32_t (*qb_ipcs_connection_accept_fn) (qb_ipcs_connection_t *c,
uid_t uid, gid_t gid);
/**
* This is called after a new connection has been created.
*
* @note A client connection is not considered connected until
* this callback is invoked.
*/
typedef void (*qb_ipcs_connection_created_fn) (qb_ipcs_connection_t *c);
/**
* This is called after a connection has been disconnected.
*
* @note This callback will only be invoked if the connection is
* successfully created.
* @note if you return anything but 0 this function will be
* repeatedly called (until 0 is returned).
*/
typedef int32_t (*qb_ipcs_connection_closed_fn) (qb_ipcs_connection_t *c);
/**
* This is called just before a connection is freed.
*/
typedef void (*qb_ipcs_connection_destroyed_fn) (qb_ipcs_connection_t *c);
/**
* This is the message processing calback.
* It is called with the message data.
*/
typedef int32_t (*qb_ipcs_msg_process_fn) (qb_ipcs_connection_t *c,
void *data, size_t size);
struct qb_ipcs_service_handlers {
qb_ipcs_connection_accept_fn connection_accept;
qb_ipcs_connection_created_fn connection_created;
qb_ipcs_msg_process_fn msg_process;
qb_ipcs_connection_closed_fn connection_closed;
qb_ipcs_connection_destroyed_fn connection_destroyed;
};
/**
* Create a new IPC server.
*
* @param name for clients to connect to.
* @param service_id an integer to associate with the service
* @param type transport type.
* @param handlers callbacks.
* @return the new service instance.
*/
qb_ipcs_service_t* qb_ipcs_create(const char *name,
int32_t service_id,
enum qb_ipc_type type,
struct qb_ipcs_service_handlers *handlers);
/**
* Increase the reference counter on the service object.
*
* @param s service instance
*/
void qb_ipcs_ref(qb_ipcs_service_t *s);
/**
* Decrease the reference counter on the service object.
*
* @param s service instance
*/
void qb_ipcs_unref(qb_ipcs_service_t *s);
/**
* Set your poll callbacks.
*
* @param s service instance
* @param handlers the handlers that you want ipcs to use.
*/
void qb_ipcs_poll_handlers_set(qb_ipcs_service_t* s,
struct qb_ipcs_poll_handlers *handlers);
/**
* Associate a "user" pointer with this service.
*
* @param s service instance
* @param context the pointer to associate with this service.
* @see qb_ipcs_service_context_get()
*/
void qb_ipcs_service_context_set(qb_ipcs_service_t* s,
void *context);
/**
* Get the context (set previously)
*
* @param s service instance
* @return the context
* @see qb_ipcs_service_context_set()
*/
void *qb_ipcs_service_context_get(qb_ipcs_service_t* s);
/**
* run the new IPC server.
* @param s service instance
* @return 0 == ok; -errno to indicate a failure. Service is destroyed on failure.
*/
int32_t qb_ipcs_run(qb_ipcs_service_t* s);
/**
* Destroy the IPC server.
*
* @param s service instance to destroy
*/
void qb_ipcs_destroy(qb_ipcs_service_t* s);
/**
* Limit the incoming request rate.
* @param s service instance
* @param rl the new rate
*/
void qb_ipcs_request_rate_limit(qb_ipcs_service_t* s,
enum qb_ipcs_rate_limit rl);
/**
* Send a response to a incoming request.
*
* @param c connection instance
* @param data the message to send
* @param size the size of the message
* @return size sent or -errno for errors
*
* @note the data must include a qb_ipc_response_header at
* the top of the message. The client will read the size field
* to determine how much to recv.
*/
ssize_t qb_ipcs_response_send(qb_ipcs_connection_t *c, const void *data,
size_t size);
/**
* Send a response to a incoming request.
*
* @param c connection instance
* @param iov the iovec struct that points to the message to send
* @param iov_len the number of iovecs.
* @return size sent or -errno for errors
*
* @note the iov[0] must be a qb_ipc_response_header. The client will
* read the size field to determine how much to recv.
*
* @note When send returns -EMSGSIZE, this means the msg is too
* large and will never succeed. To determine the max msg size
* a client can be sent, use qb_ipcs_connection_get_buffer_size()
*/
ssize_t qb_ipcs_response_sendv(qb_ipcs_connection_t *c,
const struct iovec * iov, size_t iov_len);
/**
* Send an asynchronous event message to the client.
*
* @param c connection instance
* @param data the message to send
* @param size the size of the message
* @return size sent or -errno for errors
*
* @note the data must include a qb_ipc_response_header at
* the top of the message. The client will read the size field
* to determine how much to recv.
*
* @note When send returns -EMSGSIZE, this means the msg is too
* large and will never succeed. To determine the max msg size
* a client can be sent, use qb_ipcs_connection_get_buffer_size()
*/
ssize_t qb_ipcs_event_send(qb_ipcs_connection_t *c, const void *data,
size_t size);
/**
* Send an asynchronous event message to the client.
*
* @param c connection instance
* @param iov the iovec struct that points to the message to send
* @param iov_len the number of iovecs.
* @return size sent or -errno for errors
*
* @note the iov[0] must be a qb_ipc_response_header. The client will
* read the size field to determine how much to recv.
*
* @note When send returns -EMSGSIZE, this means the msg is too
* large and will never succeed. To determine the max msg size
* a client can be sent, use qb_ipcs_connection_get_buffer_size()
*/
ssize_t qb_ipcs_event_sendv(qb_ipcs_connection_t *c, const struct iovec * iov,
size_t iov_len);
/**
* Increment the connection's reference counter.
*
* @param c connection instance
*/
void qb_ipcs_connection_ref(qb_ipcs_connection_t *c);
/**
* Decrement the connection's reference counter.
*
* @param c connection instance
*/
void qb_ipcs_connection_unref(qb_ipcs_connection_t *c);
/**
* Disconnect from this client.
*
* @param c connection instance
*/
void qb_ipcs_disconnect(qb_ipcs_connection_t *c);
/**
* Get the service id related to this connection's service.
* (as passed into qb_ipcs_create()
*
* @return service id.
*/
int32_t qb_ipcs_service_id_get(qb_ipcs_connection_t *c);
/**
* Associate a "user" pointer with this connection.
*
* @param context the point to associate with this connection.
* @param c connection instance
* @see qb_ipcs_context_get()
*/
void qb_ipcs_context_set(qb_ipcs_connection_t *c, void *context);
/**
* Get the context (set previously)
*
* @param c connection instance
* @return the context
* @see qb_ipcs_context_set()
*/
void *qb_ipcs_context_get(qb_ipcs_connection_t *c);
/**
* Get the context previously set on the service backing this connection
*
* @param c connection instance
* @return the context
* @see qb_ipcs_service_context_set
*/
void *qb_ipcs_connection_service_context_get(qb_ipcs_connection_t *c);
/**
* Get the connection statistics.
*
* @deprecated from v0.13.0 onwards, use qb_ipcs_connection_stats_get_2
* @param stats (out) the statistics structure
* @param clear_after_read clear stats after copying them into stats
* @param c connection instance
* @return 0 == ok; -errno to indicate a failure
*/
int32_t qb_ipcs_connection_stats_get(qb_ipcs_connection_t *c,
struct qb_ipcs_connection_stats* stats,
int32_t clear_after_read);
/**
* Get (and allocate) the connection statistics.
*
* @param clear_after_read clear stats after copying them into stats
* @param c connection instance
* @retval NULL if no memory or invalid connection
* @retval allocated statistics structure (user must free it).
*/
struct qb_ipcs_connection_stats_2*
qb_ipcs_connection_stats_get_2(qb_ipcs_connection_t *c,
int32_t clear_after_read);
/**
* Get the service statistics.
*
* @param stats (out) the statistics structure
* @param clear_after_read clear stats after copying them into stats
* @param pt service instance
* @return 0 == ok; -errno to indicate a failure
*/
int32_t qb_ipcs_stats_get(qb_ipcs_service_t* pt,
struct qb_ipcs_stats* stats,
int32_t clear_after_read);
/**
* Get the first connection.
*
* @note call qb_ipcs_connection_unref() after using the connection.
*
* @param pt service instance
* @return first connection
*/
qb_ipcs_connection_t * qb_ipcs_connection_first_get(qb_ipcs_service_t* pt);
/**
* Get the next connection.
*
* @note call qb_ipcs_connection_unref() after using the connection.
*
* @param pt service instance
* @param current current connection
* @return next connection
*/
qb_ipcs_connection_t * qb_ipcs_connection_next_get(qb_ipcs_service_t* pt,
qb_ipcs_connection_t *current);
/**
* Set the permissions on and shared memory files so that both processes can
* read and write to them.
*
* @param conn connection instance
* @param uid the user id to set.
* @param gid the group id to set.
* @param mode the mode to set.
*
* @see chmod() chown()
* @note this must be called within the qb_ipcs_connection_accept_fn()
* callback.
*/
void qb_ipcs_connection_auth_set(qb_ipcs_connection_t *conn, uid_t uid,
gid_t gid, mode_t mode);
/**
* Retrieve the connection ipc buffer size. This reflects the
* largest size msg that can be sent or received.
*
* @param conn connection instance
* @return msg size in bytes, negative value on error.
*/
int32_t qb_ipcs_connection_get_buffer_size(qb_ipcs_connection_t *conn);
/**
* Enforce the max buffer size clients must use from the server side.
*
* @note Setting this will force client connections to use at least
* max_buf_size bytes as their buffer size. If this value is not set
* on the server, the clients enforce their own buffer sizes.
*
* @param s ipc server instance
* @param max_buf_size represented in bytes
*/
void qb_ipcs_enforce_buffer_size(qb_ipcs_service_t *s, uint32_t max_buf_size);
/* *INDENT-OFF* */
#ifdef __cplusplus
}
#endif
/* *INDENT-ON* */
#endif /* QB_IPCS_H_DEFINED */

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