/*	$OpenBSD: snmpctl.c,v 1.4 2007/12/28 17:22:32 reyk Exp $	*/

/*
 * Copyright (c) 2007 Reyk Floeter <reyk@vantronix.net>
 * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
 * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org>
 * Copyright (c) 2003 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.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/queue.h>
#include <sys/un.h>
#include <sys/tree.h>

#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <net/if_media.h>
#include <net/if_types.h>

#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <event.h>

#include "snmpd.h"
#include "parser.h"
#include "mib.h"

__dead void	 usage(void);

struct imsgname {
	int type;
	char *name;
	void (*func)(struct imsg *);
};

void		 show_mib(void);
struct imsgname *monitor_lookup(u_int8_t);
void		 monitor_host_status(struct imsg *);
void		 monitor_id(struct imsg *);
int		 monitor(struct imsg *);

struct imsgname imsgs[] = {
	{ 0,				NULL,			NULL }
};
struct imsgname imsgunknown = {
	-1,				"<unknown>",		NULL
};

struct imsgbuf	*ibuf;
struct snmpd	*env;
struct oid	 mib_tree[] = MIB_TREE;

__dead void
usage(void)
{
	extern char *__progname;

	fprintf(stderr, "usage: %s <command> [arg [...]]\n", __progname);
	exit(1);
}

/* dummy function so that snmpctl does not need libevent */
void
imsg_event_add(struct imsgbuf *i)
{
	/* nothing */
}

int
main(int argc, char *argv[])
{
	struct sockaddr_un	 sun;
	struct parse_result	*res;
	struct imsg		 imsg;
	int			 ctl_sock;
	int			 done = 0;
	int			 n;

	if ((env = calloc(1, sizeof(struct snmpd *))) == NULL)
		err(1, "calloc");
	gettimeofday(&env->sc_starttime, NULL);
	smi_init();

	/* parse options */
	if ((res = parse(argc - 1, argv + 1)) == NULL)
		exit(1);

	switch (res->action) {
	case NONE:
		usage();
		break;
	case SHOW_MIB:
		show_mib();
		break;
	default:
		goto connect;
	}

	free(env);
	return (0);

 connect:
	/* connect to snmpd control socket */
	if ((ctl_sock = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
		err(1, "socket");

	bzero(&sun, sizeof(sun));
	sun.sun_family = AF_UNIX;
	strlcpy(sun.sun_path, SNMPD_SOCKET, sizeof(sun.sun_path));
 reconnect:
	if (connect(ctl_sock, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
		/* Keep retrying if running in monitor mode */
		if (res->action == MONITOR &&
		    (errno == ENOENT || errno == ECONNREFUSED)) {
			usleep(100);
			goto reconnect;
		}
		err(1, "connect: %s", SNMPD_SOCKET);
	}

	if ((ibuf = malloc(sizeof(struct imsgbuf))) == NULL)
		err(1, "malloc");
	imsg_init(ibuf, ctl_sock, NULL);
	done = 0;

	/* process user request */
	switch (res->action) {
	case MONITOR:
		imsg_compose(ibuf, IMSG_CTL_NOTIFY, 0, 0, -1, NULL, 0);
		break;
	case NONE:
	case SHOW_MIB:
		break;
	}

	while (ibuf->w.queued)
		if (msgbuf_write(&ibuf->w) < 0)
			err(1, "write error");

	while (!done) {
		if ((n = imsg_read(ibuf)) == -1)
			errx(1, "imsg_read error");
		if (n == 0)
			errx(1, "pipe closed");

		while (!done) {
			if ((n = imsg_get(ibuf, &imsg)) == -1)
				errx(1, "imsg_get error");
			if (n == 0)
				break;
			switch (res->action) {
			case MONITOR:
				done = monitor(&imsg);
				break;
			case NONE:
			case SHOW_MIB:
				break;
			}
			imsg_free(&imsg);
		}
	}
	close(ctl_sock);
	free(ibuf);

	return (0);
}

void
mib_init(void)
{
	/*
	 * MIB declarations (to register the OID names)
	 */
	smi_mibtree(mib_tree);
}

void
show_mib(void)
{
	struct oid	*oid;

	for (oid = NULL; (oid = smi_foreach(oid, 0)) != NULL;) {
		char	 buf[BUFSIZ];
		smi_oidstring(&oid->o_id, buf, sizeof(buf));
		printf("%s\n", buf);
	}
}

struct imsgname *
monitor_lookup(u_int8_t type)
{
	int i;

	for (i = 0; imsgs[i].name != NULL; i++)
		if (imsgs[i].type == type)
			return (&imsgs[i]);
	return (&imsgunknown);
}

int
monitor(struct imsg *imsg)
{
	time_t			 now;
	int			 done = 0;
	struct imsgname		*imn;

	now = time(NULL);

	imn = monitor_lookup(imsg->hdr.type);
	printf("%s: imsg type %u len %u peerid %u pid %d\n", imn->name,
	    imsg->hdr.type, imsg->hdr.len, imsg->hdr.peerid, imsg->hdr.pid);
	printf("\ttimestamp: %u, %s", now, ctime(&now));
	if (imn->type == -1)
		done = 1;
	if (imn->func != NULL)
		(*imn->func)(imsg);

	return (done);
}