/*      $OpenBSD: imsg.h,v 1.3 2013/12/26 17:32:33 eric Exp $   */

/*
 * Copyright (c) 2006, 2007 Pierre-Yves Ritschard <pyr@openbsd.org>
 * Copyright (c) 2006, 2007, 2008 Reyk Floeter <reyk@openbsd.org>
 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef _IMSG_H_
#define _IMSG_H_

#define IBUF_READ_SIZE          65535
#define IMSG_HEADER_SIZE        sizeof(struct imsg_hdr)
#define MAX_IMSGSIZE            16384

struct ibuf {
        TAILQ_ENTRY(ibuf)        entry;
        u_char                  *buf;
        size_t                   size;
        size_t                   max;
        size_t                   wpos;
        size_t                   rpos;
        int                      fd;
};

struct msgbuf {
        TAILQ_HEAD(, ibuf)       bufs;
        u_int32_t                queued;
        int                      fd;
};

struct ibuf_read {
        u_char                   buf[IBUF_READ_SIZE];
        u_char                  *rptr;
        size_t                   wpos;
};

struct imsg_fd {
        TAILQ_ENTRY(imsg_fd)    entry;
        int                     fd;
};

struct imsgbuf {
        TAILQ_HEAD(, imsg_fd)    fds;
        struct ibuf_read         r;
        struct msgbuf            w;
        int                      fd;
        pid_t                    pid;
};

#define IMSGF_HASFD     1

struct imsg_hdr {
        u_int32_t        type;
        u_int16_t        len;
        u_int16_t        flags;
        u_int32_t        peerid;
        u_int32_t        pid;
};

struct imsg {
        struct imsg_hdr  hdr;
        int              fd;
        void            *data;
};


/* buffer.c */
struct ibuf     *ibuf_open(size_t);
struct ibuf     *ibuf_dynamic(size_t, size_t);
int              ibuf_add(struct ibuf *, const void *, size_t);
void            *ibuf_reserve(struct ibuf *, size_t);
void            *ibuf_seek(struct ibuf *, size_t, size_t);
size_t           ibuf_size(struct ibuf *);
size_t           ibuf_left(struct ibuf *);
void             ibuf_close(struct msgbuf *, struct ibuf *);
int              ibuf_write(struct msgbuf *);
void             ibuf_free(struct ibuf *);
void             msgbuf_init(struct msgbuf *);
void             msgbuf_clear(struct msgbuf *);
int              msgbuf_write(struct msgbuf *);
void             msgbuf_drain(struct msgbuf *, size_t);

/* imsg.c */
void     imsg_init(struct imsgbuf *, int);
ssize_t  imsg_read(struct imsgbuf *);
ssize_t  imsg_get(struct imsgbuf *, struct imsg *);
int      imsg_compose(struct imsgbuf *, u_int32_t, u_int32_t, pid_t,
            int, const void *, u_int16_t);
int      imsg_composev(struct imsgbuf *, u_int32_t, u_int32_t,  pid_t,
            int, const struct iovec *, int);
struct ibuf *imsg_create(struct imsgbuf *, u_int32_t, u_int32_t, pid_t,
            u_int16_t);
int      imsg_add(struct ibuf *, const void *, u_int16_t);
void     imsg_close(struct imsgbuf *, struct ibuf *);
void     imsg_free(struct imsg *);
int      imsg_flush(struct imsgbuf *);
void     imsg_clear(struct imsgbuf *);

#endif