/* ICMP-related user commands */
#include <stdio.h>
#include "global.h"
#include "icmp.h"
#include "mbuf.h"
#include "netuser.h"
#include "internet.h"
#include "timer.h"
#include "socket.h"
#include "proc.h"
#include "session.h"
#include "cmdparse.h"
#include "commands.h"

static int doicmpec __ARGS((int argc, char *argv[],void *p));
static int doicmpstat __ARGS((int argc, char *argv[],void *p));
static int doicmptr __ARGS((int argc, char *argv[],void *p));
static void pingtx __ARGS((int s,void *ping1,void *p));
static int pingem __ARGS((int s,int32 target,int16 seq,int16 id,int16 len));

static struct cmds Icmpcmds[] = {
	"echo",		doicmpec,	0, 0, NULLCHAR,
	"status",	doicmpstat,	0, 0, NULLCHAR,
	"trace",	doicmptr,	0, 0, NULLCHAR,
	NULLCHAR
};

int Icmp_trace;
static int Icmp_echo = 1;

int
doicmp(argc,argv,p)
int argc;
char *argv[];
void *p;
{
	return subcmd(Icmpcmds,argc,argv,p);
}

static int
doicmpstat(argc,argv,p)
int argc;
char *argv[];
void *p;
{
	register int i;
	int lim;

	/* Note that the ICMP variables are shown in column order, because
	 * that lines up the In and Out variables on the same line
	 */
	lim = NUMICMPMIB/2;
	for(i=1;i<=lim;i++){
		tprintf("(%2u)%-20s%10lu",i,Icmp_mib[i].name,
		 Icmp_mib[i].value.integer);
		tprintf("     (%2u)%-20s%10lu\n",i+lim,Icmp_mib[i+lim].name,
		 Icmp_mib[i+lim].value.integer);
	}
	return 0;
}
static int
doicmptr(argc,argv,p)
int argc;
char *argv[];
void *p;
{
	return setbool(&Icmp_trace,"ICMP tracing",argc,argv);
}
static int
doicmpec(argc,argv,p)
int argc;
char *argv[];
void *p;
{
	return setbool(&Icmp_echo,"ICMP echo response accept",argc,argv);
}

/* Send ICMP Echo Request packets */
int
doping(argc,argv,p)
int argc;
char *argv[];
void *p;
{
	struct proc *pinger = NULLPROC;	/* Transmit process */
	struct sockaddr_in from;
	struct icmp icmp;
	struct mbuf *bp;
	int32 timestamp,rtt,abserr;
	int s,fromlen;
	struct ping ping;
	struct session *sp;

	memset((char *)&ping,0,sizeof(ping));
	/* Allocate a session descriptor */
	if((sp = ping.sp = newsession(argv[1],PING)) == NULLSESSION){
		tprintf("Too many sessions\n");
		freeargs(argc,argv);
		return 1;
	}
	if((sp->s = s = socket(AF_INET,SOCK_RAW,IPPROTO_ICMP)) == -1){
		tprintf("Can't create socket\n");
		freeargs(argc,argv);
		keywait(NULLCHAR,1);
		freesession(sp);
		return 1;
	}
	tprintf("Resolving %s... ",sp->name);
	if((ping.target = resolve(sp->name)) == 0){
		tprintf("Host %s unknown\n",sp->name);
		freeargs(argc,argv);
		keywait(NULLCHAR,1);
		freesession(sp);
		return 1;
	}
	if(argc > 2)
		ping.len = atoi(argv[2]);

	if(argc > 3)
		ping.interval = atol(argv[3]);

	/* This is a hack. If the specified interval is less than one tick,
	 * assume it to be in seconds. Otherwise assume milliseconds.
	 */
	if(ping.interval < MSPTICK)
		ping.interval *= (1000 / MSPTICK);
	else
		ping.interval /= MSPTICK;

	/* Optionally ping a range of IP addresses */
	if(argc > 4)
		ping.incflag = 1;

	freeargs(argc,argv);
	if(ping.interval != 0){
		pinger = newproc("pingtx",300,pingtx,s,&ping,NULL);
	} else {
		/* One shot ping; let echo_proc hook handle response.
		 * An ID of MAXINT16 will not be confused with a legal socket
		 * number, which is used to identify repeated pings
		 */
		pingem(s,ping.target,0,MAXINT16,ping.len);
		freesession(sp);
		return 0;
	}
	/* Now collect the replies */
	for(;;){
		fromlen = sizeof(from);
		if(recv_mbuf(s,&bp,0,(char *)&from,&fromlen) == -1)
			break;
		ntohicmp(&icmp,&bp);
		if(icmp.type != ICMP_ECHO_REPLY
		 || icmp.args.echo.id != s){
			/* Ignore other people's responses */
			free_p(bp);
			continue;
		}
		ping.responses++;
		/* Get stamp */
		if(pullup(&bp,(char *)&timestamp,sizeof(timestamp))
		 != sizeof(timestamp)){
			/* The timestamp is missing! */
			free_p(bp);	/* Probably not necessary */
			continue;
		}
		free_p(bp);

		/* Compute round trip time, update smoothed estimates */
		rtt = (Clock - timestamp) * MSPTICK;
		if(ping.incflag){
			tprintf("%s: rtt %lu\n",inet_ntoa(from.sin_addr.s_addr),
			 rtt);
			continue;
		}
		abserr = rtt > ping.srtt ? rtt - ping.srtt : ping.srtt - rtt;

		if(ping.responses == 1){
			/* First response, base entire SRTT on it */
			ping.srtt = rtt;
		} else {
			ping.srtt = (7*ping.srtt + rtt + 4) >> 3;
		}
		ping.mdev = (3*ping.mdev + abserr + 2) >> 2;

	}
	if(pinger != NULLPROC)
		killproc(pinger);
	freesession(sp);
	return 0;
}
void
echo_proc(source,dest,icmp,bp)
int32 source;
int32 dest;
struct icmp *icmp;
struct mbuf *bp;
{
	int32 timestamp,rtt;

	if(Icmp_echo && icmp->args.echo.id == MAXINT16
	 && pullup(&bp,(char *)&timestamp,sizeof(timestamp))
	 == sizeof(timestamp)){
		/* Compute round trip time */
		rtt = (Clock - timestamp) * MSPTICK;
		tprintf("%s: rtt %lu\n",inet_ntoa(source),rtt);
	}
	free_p(bp);
}
/* Ping transmit process. Runs until killed */
static void
pingtx(s,ping1,p)
int s;		/* Socket to use */
void *ping1;
void *p;
{
	struct ping *ping;

	ping = (struct ping *)ping1;
	ping->sent = 0;
	if(ping->incflag){
		for(;;){
			tprintf("pinging %s\n",inet_ntoa(ping->target));
			pingem(s,ping->target++,0,(int16)s,ping->len);
			pause(ping->interval);
		}
	} else {
		for(;;){
			tprintf("pinging %s: sent %lu rcvd %lu avg rtt %lu mdev %lu\n",
			 ping->sp->name,ping->sent,ping->responses,ping->srtt,
			 ping->mdev);
			pingem(s,ping->target,(int16)ping->sent++,(int16)s,ping->len);
			pause(ping->interval);
		}
	}
}


/* Send ICMP Echo Request packet */
static int
pingem(s,target,seq,id,len)
int s;		/* Raw socket on which to send ping */
int32 target;	/* Site to be pinged */
int16 seq;	/* ICMP Echo Request sequence number */
int16 id;	/* ICMP Echo Request ID */
int16 len;	/* Length of optional data field */
{
	struct mbuf *data;
	struct mbuf *bp;
	struct icmp icmp;
	struct sockaddr_in to;

	if((data = alloc_mbuf((int16)(len+sizeof(Clock)))) == NULLBUF)
		return -1;
	data->cnt = len+sizeof(Clock);
	/* Set optional data field, if any, to all 55's */
	if(len != 0)
		memset(data->data+sizeof(Clock),0x55,len);

	/* Insert timestamp and build ICMP header */
	memcpy(data->data,(char *)&Clock,sizeof(Clock));
	icmpOutEchos++;
	icmpOutMsgs++;
	icmp.type = ICMP_ECHO;
	icmp.code = 0;
	icmp.args.echo.seq = seq;
	icmp.args.echo.id = id;
	if((bp = htonicmp(&icmp,data)) == NULLBUF){
		free_p(data);
		return 0;
	}
	to.sin_family = AF_INET;
	to.sin_addr.s_addr = target;
	send_mbuf(s,bp,0,(char *)&to,sizeof(to));
	return 0;
}