/*      $OpenBSD: imsg.h,v 1.24 2025/06/05 08:55:07 tb Exp $    */

/*
 * Copyright (c) 2023 Claudio Jeker <claudio@openbsd.org>
 * 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_

#include <sys/types.h>
#include <sys/queue.h>
#include <stddef.h>
#include <stdint.h>

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

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

struct ibufqueue;
struct msgbuf;

struct imsgbuf {
        struct msgbuf           *w;
        pid_t                    pid;
        uint32_t                 maxsize;
        int                      fd;
        int                      flags;
};

struct imsg_hdr {
        uint32_t         type;
        uint32_t         len;
        uint32_t         peerid;
        uint32_t         pid;
};

struct imsg {
        struct imsg_hdr  hdr;
        void            *data;
        struct ibuf     *buf;
};

struct iovec;

/* imsg-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);
int              ibuf_add_ibuf(struct ibuf *, const struct ibuf *);
int              ibuf_add_zero(struct ibuf *, size_t);
int              ibuf_add_n8(struct ibuf *, uint64_t);
int              ibuf_add_n16(struct ibuf *, uint64_t);
int              ibuf_add_n32(struct ibuf *, uint64_t);
int              ibuf_add_n64(struct ibuf *, uint64_t);
int              ibuf_add_h16(struct ibuf *, uint64_t);
int              ibuf_add_h32(struct ibuf *, uint64_t);
int              ibuf_add_h64(struct ibuf *, uint64_t);
int              ibuf_add_strbuf(struct ibuf *, const char *, size_t);
void            *ibuf_reserve(struct ibuf *, size_t);
void            *ibuf_seek(struct ibuf *, size_t, size_t);
int              ibuf_set(struct ibuf *, size_t, const void *, size_t);
int              ibuf_set_n8(struct ibuf *, size_t, uint64_t);
int              ibuf_set_n16(struct ibuf *, size_t, uint64_t);
int              ibuf_set_n32(struct ibuf *, size_t, uint64_t);
int              ibuf_set_n64(struct ibuf *, size_t, uint64_t);
int              ibuf_set_h16(struct ibuf *, size_t, uint64_t);
int              ibuf_set_h32(struct ibuf *, size_t, uint64_t);
int              ibuf_set_h64(struct ibuf *, size_t, uint64_t);
int              ibuf_set_maxsize(struct ibuf *, size_t);
void            *ibuf_data(const struct ibuf *);
size_t           ibuf_size(const struct ibuf *);
size_t           ibuf_left(const struct ibuf *);
int              ibuf_truncate(struct ibuf *, size_t);
void             ibuf_rewind(struct ibuf *);
void             ibuf_close(struct msgbuf *, struct ibuf *);
void             ibuf_from_buffer(struct ibuf *, void *, size_t);
void             ibuf_from_ibuf(struct ibuf *, const struct ibuf *);
int              ibuf_get(struct ibuf *, void *, size_t);
int              ibuf_get_ibuf(struct ibuf *, size_t, struct ibuf *);
int              ibuf_get_n8(struct ibuf *, uint8_t *);
int              ibuf_get_n16(struct ibuf *, uint16_t *);
int              ibuf_get_n32(struct ibuf *, uint32_t *);
int              ibuf_get_n64(struct ibuf *, uint64_t *);
int              ibuf_get_h16(struct ibuf *, uint16_t *);
int              ibuf_get_h32(struct ibuf *, uint32_t *);
int              ibuf_get_h64(struct ibuf *, uint64_t *);
char            *ibuf_get_string(struct ibuf *, size_t);
int              ibuf_get_strbuf(struct ibuf *, char *, size_t);
int              ibuf_skip(struct ibuf *, size_t);
void             ibuf_free(struct ibuf *);
int              ibuf_fd_avail(struct ibuf *);
int              ibuf_fd_get(struct ibuf *);
void             ibuf_fd_set(struct ibuf *, int);
struct msgbuf   *msgbuf_new(void);
struct msgbuf   *msgbuf_new_reader(size_t,
                    struct ibuf *(*)(struct ibuf *, void *, int *), void *);
void             msgbuf_free(struct msgbuf *);
void             msgbuf_clear(struct msgbuf *);
void             msgbuf_concat(struct msgbuf *, struct ibufqueue *);
uint32_t         msgbuf_queuelen(struct msgbuf *);
int              ibuf_write(int, struct msgbuf *);
int              msgbuf_write(int, struct msgbuf *);
int              ibuf_read(int, struct msgbuf *);
int              msgbuf_read(int, struct msgbuf *);
struct ibuf     *msgbuf_get(struct msgbuf *);

struct ibufqueue        *ibufq_new(void);
void             ibufq_free(struct ibufqueue *);
struct ibuf     *ibufq_pop(struct ibufqueue *bufq);
void             ibufq_push(struct ibufqueue *, struct ibuf *);
uint32_t         ibufq_queuelen(struct ibufqueue *);
void             ibufq_concat(struct ibufqueue *, struct ibufqueue *);
void             ibufq_flush(struct ibufqueue *);

/* imsg.c */
int      imsgbuf_init(struct imsgbuf *, int);
void     imsgbuf_allow_fdpass(struct imsgbuf *imsgbuf);
int      imsgbuf_set_maxsize(struct imsgbuf *, uint32_t);
int      imsgbuf_read(struct imsgbuf *);
int      imsgbuf_write(struct imsgbuf *);
int      imsgbuf_flush(struct imsgbuf *);
void     imsgbuf_clear(struct imsgbuf *);
uint32_t imsgbuf_queuelen(struct imsgbuf *);
int      imsgbuf_get(struct imsgbuf *, struct imsg *);
ssize_t  imsg_get(struct imsgbuf *, struct imsg *);
int      imsg_ibufq_pop(struct ibufqueue *, struct imsg *);
void     imsg_ibufq_push(struct ibufqueue *, struct imsg *);
int      imsg_get_ibuf(struct imsg *, struct ibuf *);
int      imsg_get_data(struct imsg *, void *, size_t);
int      imsg_get_buf(struct imsg *, void *, size_t);
int      imsg_get_strbuf(struct imsg *, char *, size_t);
int      imsg_get_fd(struct imsg *);
uint32_t imsg_get_id(struct imsg *);
size_t   imsg_get_len(struct imsg *);
pid_t    imsg_get_pid(struct imsg *);
uint32_t imsg_get_type(struct imsg *);
int      imsg_forward(struct imsgbuf *, struct imsg *);
int      imsg_compose(struct imsgbuf *, uint32_t, uint32_t, pid_t, int,
            const void *, size_t);
int      imsg_composev(struct imsgbuf *, uint32_t, uint32_t,  pid_t, int,
            const struct iovec *, int);
int      imsg_compose_ibuf(struct imsgbuf *, uint32_t, uint32_t, pid_t,
            struct ibuf *);
struct ibuf *imsg_create(struct imsgbuf *, uint32_t, uint32_t, pid_t, size_t);
int      imsg_add(struct ibuf *, const void *, size_t);
void     imsg_close(struct imsgbuf *, struct ibuf *);
void     imsg_free(struct imsg *);
int      imsg_set_maxsize(struct ibuf *, size_t);

#endif