/*
 * Copyright (c) 2010-2015 Reyk Floeter <reyk@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.
 */

/* imsg */
struct imsgev {
	struct imsgbuf		 ibuf;
	void			(*handler)(int, short, void *);
	struct event		 ev;
	struct privsep_proc	*proc;
	void			*data;
	short			 events;
};

#define IMSG_SIZE_CHECK(imsg, p) do {					\
	if (IMSG_DATA_SIZE(imsg) < sizeof(*p))				\
		fatalx("bad length imsg received (%s)",	#p);		\
} while (0)
#define IMSG_DATA_SIZE(imsg)	((imsg)->hdr.len - IMSG_HEADER_SIZE)

/* privsep */
enum privsep_procid {
	PROC_PARENT,
	PROC_PROXY,
	PROC_MAX,
};

#define CONFIG_RELOAD		0x00
#define CONFIG_SOCKS		0x01
#define CONFIG_ALL		0xff

struct privsep_pipes {
	int				*pp_pipes[PROC_MAX];
};

struct privsep {
	struct privsep_pipes		*ps_pipes[PROC_MAX];
	struct privsep_pipes		*ps_pp;

	struct imsgev			*ps_ievs[PROC_MAX];
	const char			*ps_title[PROC_MAX];
	uint8_t				 ps_what[PROC_MAX];

	struct passwd			*ps_pw;
	int				 ps_noaction;

	unsigned int			 ps_instances[PROC_MAX];
	unsigned int			 ps_instance;

	/* Event and signal handlers */
	struct event			 ps_evsigint;
	struct event			 ps_evsigterm;
	struct event			 ps_evsigchld;
	struct event			 ps_evsighup;

	void				*ps_env;
};

struct privsep_proc {
	const char		*p_title;
	enum privsep_procid	 p_id;
	int			(*p_cb)(int, struct privsep_proc *,
				    struct imsg *);
	void			(*p_init)(struct privsep *,
				    struct privsep_proc *);
	void			(*p_shutdown)(void);
	const char		*p_chroot;
	struct passwd		*p_pw;
	struct privsep		*p_ps;
};

struct privsep_fd {
	enum privsep_procid		 pf_procid;
	unsigned int			 pf_instance;
};

/* proc.c */
void	 proc_init(struct privsep *, struct privsep_proc *, unsigned int,
	    int, int, char **, enum privsep_procid);
void	 proc_kill(struct privsep *);
void	 proc_connect(struct privsep *ps);
void	 proc_dispatch(int, short event, void *);
void	 proc_range(struct privsep *, enum privsep_procid, int *, int *);
void	 proc_run(struct privsep *, struct privsep_proc *,
	    struct privsep_proc *, unsigned int,
	    void (*)(struct privsep *, struct privsep_proc *, void *), void *);
void	 imsg_event_add(struct imsgev *);
int	 imsg_compose_event(struct imsgev *, uint16_t, uint32_t,
	    pid_t, int, void *, uint16_t);
int	 imsg_composev_event(struct imsgev *, uint16_t, uint32_t,
	    pid_t, int, const struct iovec *, int);
int	 proc_compose_imsg(struct privsep *, enum privsep_procid, int,
	    uint16_t, uint32_t, int, void *, uint16_t);
int	 proc_compose(struct privsep *, enum privsep_procid,
	    uint16_t, void *data, uint16_t);
int	 proc_composev_imsg(struct privsep *, enum privsep_procid, int,
	    uint16_t, uint32_t, int, const struct iovec *, int);
int	 proc_composev(struct privsep *, enum privsep_procid,
	    uint16_t, const struct iovec *, int);
int	 proc_forward_imsg(struct privsep *, struct imsg *,
	    enum privsep_procid, int);
struct imsgbuf *
	 proc_ibuf(struct privsep *, enum privsep_procid, int);
struct imsgev *
	 proc_iev(struct privsep *, enum privsep_procid, int);
enum privsep_procid
	 proc_getid(struct privsep_proc *, unsigned int, const char *);
int	 proc_flush_imsg(struct privsep *, enum privsep_procid, int);