/*-
 * 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. 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 $
 */

/*
 * 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_ISIPV4(inp))
                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 = NULL;
        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 = NULL;
        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 == NULL) {
                        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);
}