/*-
 * Copyright (c) 1980, 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * @(#)netstat.c	8.1 (Berkeley) 6/6/93
 * $FreeBSD: src/usr.bin/systat/netstat.c,v 1.13 1999/08/30 08:18:08 peter Exp $
 * $DragonFly: src/usr.bin/systat/netstat.c,v 1.11 2008/11/10 04:59:45 swildner Exp $
 */

/*
 * netstat
 */
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
#include <sys/sysctl.h>

#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/route.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#ifdef INET6
#include <netinet/ip6.h>
#endif
#include <netinet/in_pcb.h>
#include <netinet/ip_icmp.h>
#include <netinet/icmp_var.h>
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <netinet/tcpip.h>
#include <netinet/tcp_seq.h>
#define TCPSTATES
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcp_debug.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>

#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <stdlib.h>
#include <string.h>
#include <nlist.h>
#include <paths.h>
#include "systat.h"
#include "extern.h"

static void enter(struct inpcb *, struct xsocket *, int, const char *);
static char *inetname(struct in_addr);
static void inetprint(struct in_addr *, int, const char *);

#define	streq(a,b)	(strcmp(a,b)==0)
#define	YMAX(w)		((w)->_maxy-1)

WINDOW *
opennetstat(void)
{
	sethostent(1);
	setnetent(1);
	return (subwin(stdscr, LINES-5-1, 0, 5, 0));
}

struct netinfo {
	struct	netinfo *ni_forw, *ni_prev;
	short	ni_line;		/* line on screen */
	short	ni_seen;		/* 0 when not present in list */
	short	ni_flags;
#define	NIF_LACHG	0x1		/* local address changed */
#define	NIF_FACHG	0x2		/* foreign address changed */
	short	ni_state;		/* tcp state */
	const char *ni_proto;		/* protocol */
	struct	in_addr ni_laddr;	/* local address */
	long	ni_lport;		/* local port */
	struct	in_addr	ni_faddr;	/* foreign address */
	long	ni_fport;		/* foreign port */
	long	ni_rcvcc;		/* rcv buffer character count */
	long	ni_sndcc;		/* snd buffer character count */
};

static struct {
	struct	netinfo *ni_forw, *ni_prev;
} netcb;

static	int aflag = 0;
static	int nflag = 0;
static	int lastrow = 1;

void
closenetstat(WINDOW *w)
{
	struct netinfo *p;

	endhostent();
	endnetent();
	p = (struct netinfo *)netcb.ni_forw;
	while (p != (struct netinfo *)&netcb) {
		if (p->ni_line != -1)
			lastrow--;
		p->ni_line = -1;
		p = p->ni_forw;
	}
        if (w != NULL) {
		wclear(w);
		wrefresh(w);
		delwin(w);
	}
}

int
initnetstat(void)
{
	netcb.ni_forw = netcb.ni_prev = (struct netinfo *)&netcb;
	protos = TCP|UDP;
	return(1);
}

static void
enter_tcp(void *xig)
{
	struct xtcpcb *xtcp = (struct xtcpcb *)xig;
	struct xsocket *xso;
	int state;

	if (xtcp->xt_len < sizeof(*xtcp))
		return;
	xso = &xtcp->xt_socket;
	state = xtcp->xt_tp.t_state;
	enter(&xtcp->xt_inp, xso, state, "tcp");
}

static void
enter_udp(void *xig)
{
	struct xinpcb *xinp = (struct xinpcb *)xig;
	struct xsocket *xso;

	if (xinp->xi_len < sizeof(*xinp))
		return;
	xso = &xinp->xi_socket;
	enter(&xinp->xi_inp, xso, 0, "udp");
}

static void
fetchnetstat_proto(void (*enter_proto)(void *),
    const char *mibvar)
{
	char *buf, *buf2;
	size_t i, len, elem_len;

	if (sysctlbyname(mibvar, 0, &len, 0, 0) < 0) {
		if (errno != ENOENT)
			warn("sysctl: %s", mibvar);
		return;
	}
	if ((buf = malloc(len)) == NULL) {
		warn("malloc %lu bytes", (u_long)len);
		return;
	}
	if (sysctlbyname(mibvar, buf, &len, 0, 0) < 0) {
		warn("sysctl: %s", mibvar);
		free(buf);
		return;
	}

	/*
	 * XXX this is better with a single PCB type
	 */
	if (len == 0) {
		free(buf);
		return;
	}
	if (len < sizeof(size_t)) {
		warnx("sysctl: short read");
		free(buf);
		return;
	}
	elem_len = *(size_t *)buf;
	len /= elem_len;
	buf2 = buf;
	for (i = 0; i < len; i++, buf2 += elem_len) {
		if (*(size_t *)(buf2) != elem_len) {
			warn("sysctl: inconsistent PCB len");
			free(buf);
			return;
		}
		enter_proto(buf2);
	}
	free(buf);
}

void
fetchnetstat(void)
{
	struct netinfo *p;

	for (p = netcb.ni_forw; p != (struct netinfo *)&netcb; p = p->ni_forw)
		p->ni_seen = 0;
	if (protos & TCP)
		fetchnetstat_proto(enter_tcp, "net.inet.tcp.pcblist");
	if (protos & UDP)
		fetchnetstat_proto(enter_udp, "net.inet.udp.pcblist");
}

static void
enter(struct inpcb *inp, struct xsocket *so, int state, const char *proto)
{
	struct netinfo *p;

	if (!aflag && inet_lnaof(inp->inp_laddr) == INADDR_ANY)
		return;
	if (nhosts && !checkhost(inp))
		return;
	if (nports && !checkport(inp))
		return;
	/*
	 * pcblist may return non-ipv4 sockets, but at the moment
	 * -netstat code doesn't support other than ipv4.
	 */
	if ((inp->inp_vflag & INP_IPV4) == 0)
		return;
	/*
	 * Only take exact matches, any sockets with
	 * previously unbound addresses will be deleted
	 * below in the display routine because they
	 * will appear as ``not seen'' in the kernel
	 * data structures.
	 */
	for (p = netcb.ni_forw; p != (struct netinfo *)&netcb; p = p->ni_forw) {
		if (!streq(proto, p->ni_proto))
			continue;
		if (p->ni_lport != inp->inp_lport ||
		    p->ni_laddr.s_addr != inp->inp_laddr.s_addr)
			continue;
		if (p->ni_faddr.s_addr == inp->inp_faddr.s_addr &&
		    p->ni_fport == inp->inp_fport)
			break;
	}
	if (p == (struct netinfo *)&netcb) {
		if ((p = malloc(sizeof(*p))) == NULL) {
			error("Out of memory");
			return;
		}
		p->ni_prev = (struct netinfo *)&netcb;
		p->ni_forw = netcb.ni_forw;
		netcb.ni_forw->ni_prev = p;
		netcb.ni_forw = p;
		p->ni_line = -1;
		p->ni_laddr = inp->inp_laddr;
		p->ni_lport = inp->inp_lport;
		p->ni_faddr = inp->inp_faddr;
		p->ni_fport = inp->inp_fport;
		p->ni_proto = proto;
		p->ni_flags = NIF_LACHG|NIF_FACHG;
	}
	p->ni_rcvcc = so->so_rcv.sb_cc;
	p->ni_sndcc = so->so_snd.sb_cc;
	p->ni_state = state;
	p->ni_seen = 1;
}

/* column locations */
#define	LADDR	0
#define	FADDR	LADDR+22
#define	CPUID	FADDR+22
#define	PROTO	CPUID+4
#define	RCVCC	PROTO+6
#define	SNDCC	RCVCC+7
#define	STATE	SNDCC+7


void
labelnetstat(void)
{
	wmove(wnd, 0, 0); wclrtobot(wnd);
	mvwaddstr(wnd, 0, LADDR, "Local Address");
	mvwaddstr(wnd, 0, FADDR, "Foreign Address");
	mvwaddstr(wnd, 0, PROTO, "Proto");
	mvwaddstr(wnd, 0, RCVCC, "Recv-Q");
	mvwaddstr(wnd, 0, SNDCC, "Send-Q");
	mvwaddstr(wnd, 0, STATE, "(state)");
}

void
shownetstat(void)
{
	struct netinfo *p, *q;

	/*
	 * First, delete any connections that have gone
	 * away and adjust the position of connections
	 * below to reflect the deleted line.
	 */
	p = netcb.ni_forw;
	while (p != (struct netinfo *)&netcb) {
		if (p->ni_line == -1 || p->ni_seen) {
			p = p->ni_forw;
			continue;
		}
		wmove(wnd, p->ni_line, 0); wdeleteln(wnd);
		q = netcb.ni_forw;
		for (; q != (struct netinfo *)&netcb; q = q->ni_forw)
			if (q != p && q->ni_line > p->ni_line) {
				q->ni_line--;
				/* this shouldn't be necessary */
				q->ni_flags |= NIF_LACHG|NIF_FACHG;
			}
		lastrow--;
		q = p->ni_forw;
		p->ni_prev->ni_forw = p->ni_forw;
		p->ni_forw->ni_prev = p->ni_prev;
		free(p);
		p = q;
	}
	/*
	 * Update existing connections and add new ones.
	 */
	for (p = netcb.ni_forw; p != (struct netinfo *)&netcb; p = p->ni_forw) {
		if (p->ni_line == -1) {
			/*
			 * Add a new entry if possible.
			 */
			if (lastrow > YMAX(wnd))
				continue;
			p->ni_line = lastrow++;
			p->ni_flags |= NIF_LACHG|NIF_FACHG;
		}
		if (p->ni_flags & NIF_LACHG) {
			wmove(wnd, p->ni_line, LADDR);
			inetprint(&p->ni_laddr, p->ni_lport, p->ni_proto);
			p->ni_flags &= ~NIF_LACHG;
		}
		if (p->ni_flags & NIF_FACHG) {
			wmove(wnd, p->ni_line, FADDR);
			inetprint(&p->ni_faddr, p->ni_fport, p->ni_proto);
			p->ni_flags &= ~NIF_FACHG;
		}
		mvwaddstr(wnd, p->ni_line, PROTO, p->ni_proto);
		mvwprintw(wnd, p->ni_line, RCVCC, "%6d", p->ni_rcvcc);
		mvwprintw(wnd, p->ni_line, SNDCC, "%6d", p->ni_sndcc);
		if (streq(p->ni_proto, "tcp")) {
			if (p->ni_state < 0 || p->ni_state >= TCP_NSTATES)
				mvwprintw(wnd, p->ni_line, STATE, "%d",
				    p->ni_state);
			else
				mvwaddstr(wnd, p->ni_line, STATE,
				    tcpstates[p->ni_state]);
		}
		wclrtoeol(wnd);
	}
	if (lastrow < YMAX(wnd)) {
		wmove(wnd, lastrow, 0); wclrtobot(wnd);
		wmove(wnd, YMAX(wnd), 0); wdeleteln(wnd);	/* XXX */
	}
}

/*
 * Pretty print an Internet address (net address + port).
 * If the nflag was specified, use numbers instead of names.
 */
static void
inetprint(struct in_addr *in, int port, const char *proto)
{
	struct servent *sp = 0;
	char line[80], *cp;

	snprintf(line, sizeof(line), "%.*s.", 16, inetname(*in));
	cp = strchr(line, '\0');
	if (!nflag && port)
		sp = getservbyport(port, proto);
	if (sp || port == 0)
		snprintf(cp, sizeof(line) - (cp - line), "%.8s", 
		    sp ? sp->s_name : "*");
	else
		snprintf(cp, sizeof(line) - (cp - line), "%d", 
		    ntohs((u_short)port));
	/* pad to full column to clear any garbage */
	cp = strchr(line, '\0');
	while (cp - line < 22)
		*cp++ = ' ';
	line[22] = '\0';
	waddstr(wnd, line);
}

/*
 * Construct an Internet address representation.
 * If the nflag has been supplied, give
 * numeric value, otherwise try for symbolic name.
 */
static char *
inetname(struct in_addr in)
{
	char *cp = 0;
	static char line[50];
	struct hostent *hp;
	struct netent *np;

	if (!nflag && in.s_addr != INADDR_ANY) {
		int net = inet_netof(in);
		int lna = inet_lnaof(in);

		if (lna == INADDR_ANY) {
			np = getnetbyaddr(net, AF_INET);
			if (np)
				cp = np->n_name;
		}
		if (cp == 0) {
			hp = gethostbyaddr(&in, sizeof (in), AF_INET);
			if (hp)
				cp = hp->h_name;
		}
	}
	if (in.s_addr == INADDR_ANY)
		strcpy(line, "*");
	else if (cp)
		snprintf(line, sizeof(line), "%s", cp);
	else {
		in.s_addr = ntohl(in.s_addr);
#define C(x)	((x) & 0xff)
		snprintf(line, sizeof(line), "%u.%u.%u.%u", C(in.s_addr >> 24),
			C(in.s_addr >> 16), C(in.s_addr >> 8), C(in.s_addr));
	}
	return (line);
}

int
cmdnetstat(const char *cmd, char *args)
{
	struct netinfo *p;

	if (prefix(cmd, "all")) {
		aflag = !aflag;
		goto fixup;
	}
	if  (prefix(cmd, "numbers") || prefix(cmd, "names")) {
		int new;

		new = prefix(cmd, "numbers");
		if (new == nflag)
			return (1);
		p = netcb.ni_forw;
		for (; p != (struct netinfo *)&netcb; p = p->ni_forw) {
			if (p->ni_line == -1)
				continue;
			p->ni_flags |= NIF_LACHG|NIF_FACHG;
		}
		nflag = new;
		goto redisplay;
	}
	if (!netcmd(cmd, args))
		return (0);
fixup:
	fetchnetstat();
redisplay:
	shownetstat();
	refresh();
	return (1);
}