1 files changed, 369 insertions, 0 deletions
diff --git a/appl/cmd/ip/ping.b b/appl/cmd/ip/ping.b
new file mode 100644
index 00000000..a148c1e6
--- /dev/null
+++ b/appl/cmd/ip/ping.b
@@ -0,0 +1,369 @@
+implement Ping;
+
+include "sys.m";
+	sys: Sys;
+
+include "draw.m";
+
+include "ip.m";
+	ip: IP;
+	IPaddr: import ip;
+
+include "timers.m";
+	timers: Timers;
+	Timer: import timers;
+
+include "rand.m";
+	rand: Rand;
+
+include "arg.m";
+
+Ping: module
+{
+	init:	fn(nil: ref Draw->Context, nil: list of string);
+};
+
+Icmp: adt
+{
+	ttl:	int;	# time to live
+	src:	IPaddr;
+	dst:	IPaddr;
+	ptype:	int;
+	code:	int;
+	seq:	int;
+	munged:	int;
+	time:	big;
+
+	unpack:	fn(b: array of byte): ref Icmp;
+};
+
+# packet types
+EchoReply: con 0;
+Unreachable: con 3;
+SrcQuench: con 4;
+EchoRequest: con 8;
+TimeExceed: con 11;
+Timestamp: con 13;
+TimestampReply: con 14;
+InfoRequest: con 15;
+InfoReply: con 16;
+
+Nmsg: con 32;
+Interval: con 1000;	# ms
+
+Req: adt
+{
+	seq:	int;	# sequence number
+	time:	big;	# time sent
+	rtt:	big;
+	ttl:	int;
+	replied:	int;
+};
+
+debug := 0;
+quiet := 0;
+lostonly := 0;
+lostmsgs := 0;
+rcvdmsgs := 0;
+sum := big 0;
+firstseq := 0;
+addresses := 0;
+
+init(nil: ref Draw->Context, args: list of string)
+{
+	sys = load Sys Sys->PATH;
+	rand = load Rand Rand->PATH;
+	timers = load Timers Timers->PATH;
+	ip = load IP IP->PATH;
+	ip->init();
+
+
+	msglen := interval := 0;
+	nmsg := Nmsg;
+
+	arg := load Arg Arg->PATH;
+	arg->init(args);
+	arg->setusage("ip/ping [-alq] [-s msgsize] [-i millisecs] [-n #pings] destination");
+	while((o := arg->opt()) != 0)
+		case o {
+		'l' =>
+			lostonly++;
+		'd' =>
+			debug++;
+		's' =>
+			msglen = int arg->earg();
+		'i' =>
+			interval = int arg->earg();
+		'n' =>
+			nmsg = int arg->earg();
+		'a' =>
+			addresses = 1;
+		'q' =>
+			quiet = 1;
+		}
+	if(msglen < 32)
+		msglen = 64;
+	if(msglen >= 65*1024)
+		msglen = 65*1024-1;
+	if(interval <= 0)
+		interval = Interval;
+
+	args = arg->argv();
+	if(args == nil)
+		arg->usage();
+	arg = nil;
+
+	sys->pctl(Sys->NEWPGRP|Sys->FORKFD, nil);
+	opentime();
+	rand->init(int(nsec()/big 1000));
+
+	addr := netmkaddr(hd args, "icmp", "1");
+	(ok, c) := sys->dial(addr, nil);
+	if(ok < 0){
+		sys->fprint(sys->fildes(2), "ip/ping: can't dial %s: %r\n", addr);
+		raise "fail:dial";
+	}
+
+	sys->print("sending %d %d byte messages %d ms apart\n", nmsg, msglen, interval);
+
+	done := chan of int;
+	reqs := chan of ref Req;
+
+	spawn sender(c.dfd, msglen, interval, nmsg, done, reqs);
+	spid := <-done;
+
+	pids := chan of int;
+	replies := chan [8] of ref Icmp;
+	spawn reader(c.dfd, msglen, replies, pids);
+	rpid := <-pids;
+
+	tpid := 0;
+	timeout := chan of int;
+	requests: list of ref Req;
+Work:
+	for(;;) alt{
+	r := <-reqs =>
+		requests = r :: requests;
+	ic := <-replies =>
+		if(ic == nil){
+			rpid = 0;
+			break Work;
+		}
+		if(ic.munged)
+			sys->print("corrupted reply\n");
+		if(ic.ptype != EchoReply || ic.code != 0){
+			sys->print("bad type/code %d/%d seq %d\n",
+				ic.ptype, ic.code, ic.seq);
+			continue;
+		}
+		requests = clean(requests, ic);
+		if(lostmsgs+rcvdmsgs == nmsg)
+			break Work;
+	<-done =>
+		spid = 0;
+		# must be at least one message outstanding; wait for it
+		tpid = timers->init(Timers->Sec);
+		timeout = Timer.start((nmsg-lostmsgs-rcvdmsgs)*interval+5*Timers->Sec).timeout;
+	<-timeout =>
+		break Work;
+	}
+	kill(rpid);
+	kill(spid);
+	kill(tpid);
+	
+	for(; requests != nil; requests = tl requests)
+		if((hd requests).replied == 0)
+			lostmsgs++;
+
+	if(lostmsgs){
+		sys->print("%d out of %d message(s) lost\n", lostmsgs, lostmsgs+rcvdmsgs);
+		raise "fail:lost messages";
+	}
+}
+
+kill(pid: int)
+{
+	if(pid)
+		sys->fprint(sys->open("#p/"+string pid+"/ctl", Sys->OWRITE), "kill");
+}
+
+SECOND: con big 1000000000;	# nanoseconds
+MINUTE: con big 60*SECOND;
+
+clean(l: list of ref Req, ip: ref Icmp): list of ref Req
+{
+	left: list of ref Req;
+	for(; l != nil; l = tl l){
+		r := hd l;
+		if(ip.seq == r.seq){
+			r.rtt = ip.time-r.time;
+			r.ttl = ip.ttl;
+			reply(r, ip);
+		}
+		if(ip.time-r.time > MINUTE){
+			r.rtt = ip.time-r.time;
+			r.ttl = ip.ttl;
+			if(!r.replied)
+				lost(r, ip);
+		}else
+			left = r :: left;
+	}
+	return left;
+}
+
+sender(fd: ref Sys->FD, msglen: int, interval: int, n: int, done: chan of int, reqs: chan of ref Req)
+{
+
+	done <-= sys->pctl(0, nil);
+
+	firstseq = rand->rand(65536) - n;	# -n to ensure we don't exceed 16 bits
+	if(firstseq < 0)
+		firstseq = 0;
+
+	buf := array[64*1024+512] of {* => byte 0};
+	for(i := Odata; i < msglen; i++)
+		buf[i] = byte i;
+	buf[Otype] = byte EchoRequest;
+	buf[Ocode] = byte 0;
+
+	seq := firstseq;
+	for(i = 0; i < n; i++){
+		if(i != 0)
+			sys->sleep(interval);
+		ip->put2(buf, Oseq, seq);	# order?
+		r := ref Req;
+		r.seq = seq;
+		r.replied = 0;
+		r.time = nsec();
+		reqs <-= r;
+		if(sys->write(fd, buf, msglen) < msglen){
+			sys->fprint(sys->fildes(2), "ping: write failed: %r\n");
+			break;
+		}
+		seq++;
+	}
+	done <-= 1;
+}
+
+reader(fd: ref Sys->FD, msglen: int, out: chan of ref Icmp, pid: chan of int)
+{
+	pid <-= sys->pctl(0, nil);
+	buf := array[64*1024+512] of byte;
+	while((n := sys->read(fd, buf, len buf)) > 0){
+		now := nsec();
+		if(n < msglen){
+			sys->print("bad len %d/%d\n", n, msglen);
+			continue;
+		}
+		ic := Icmp.unpack(buf[0:n]);
+		ic.munged = 0;
+		for(i := Odata; i < msglen; i++)
+			if(buf[i] != byte i)
+				ic.munged++;
+		ic.time = now;
+		out <-= ic;
+	}
+	sys->print("read: %r\n");
+	out <-= nil;
+}
+
+reply(r: ref Req, ic: ref Icmp)
+{
+	rcvdmsgs++;
+	r.rtt /= big 1000;
+	sum += r.rtt;
+	if(!quiet && !lostonly){
+		if(addresses)
+			sys->print("%ud: %s->%s rtt %bd µs, avg rtt %bd µs, ttl = %d\n",
+				r.seq-firstseq,
+				ic.src.text(), ic.dst.text(),
+				r.rtt, sum/big rcvdmsgs, r.ttl);
+		else
+			sys->print("%ud: rtt %bd µs, avg rtt %bd µs, ttl = %d\n",
+				r.seq-firstseq,
+				r.rtt, sum/big rcvdmsgs, r.ttl);
+	}
+	r.replied = 1;	# TO DO: duplicates might be interesting
+}
+
+lost(r: ref Req, ic: ref Icmp)
+{
+	if(!quiet){
+		if(addresses)
+			sys->print("lost %ud: %s->%s avg rtt %bd µs\n",
+				r.seq-firstseq,
+				ic.src.text(), ic.dst.text(),
+				sum/big rcvdmsgs);
+		else
+			sys->print("lost %ud: avg rtt %bd µs\n",
+				r.seq-firstseq,
+				sum/big rcvdmsgs);
+	}
+	lostmsgs++;
+}
+
+Ovihl: con 0;
+Otos: con 1;
+Olength: con 2;
+Oid: con Olength+2;
+Ofrag: con Oid+2;
+Ottl: con Ofrag+2;
+Oproto: con Ottl+1;
+Oipcksum: con Oproto+1;
+Osrc: con Oipcksum+2;
+Odst: con Osrc+4;
+Otype: con Odst+4;
+Ocode: con Otype+1;
+Ocksum: con Ocode+1;
+Oicmpid: con Ocksum+2;
+Oseq: con Oicmpid+2;
+Odata: con Oseq+2;
+
+Icmp.unpack(b: array of byte): ref Icmp
+{
+	ic := ref Icmp;
+	ic.ttl = int b[Ottl];
+	ic.src = IPaddr.newv4(b[Osrc:]);
+	ic.dst = IPaddr.newv4(b[Odst:]);
+	ic.ptype = int b[Otype];
+	ic.code = int b[Ocode];
+	ic.seq = ip->get2(b, Oseq);
+	ic.munged = 0;
+	ic.time = big 0;
+	return ic;
+}
+
+netmkaddr(addr, net, svc: string): string
+{
+	if(net == nil)
+		net = "net";
+	(n, l) := sys->tokenize(addr, "!");
+	if(n <= 1){
+		if(svc== nil)
+			return sys->sprint("%s!%s", net, addr);
+		return sys->sprint("%s!%s!%s", net, addr, svc);
+	}
+	if(svc == nil || n > 2)
+		return addr;
+	return sys->sprint("%s!%s", addr, svc);
+}
+
+timefd: ref Sys->FD;
+
+opentime()
+{
+	timefd = sys->open("/dev/time", Sys->OREAD);
+	if(timefd == nil){
+		sys->fprint(sys->fildes(2), "ping: can't open /dev/time: %r\n");
+		raise "fail:no time";
+	}
+}
+
+nsec(): big
+{
+	buf := array[64] of byte;
+	n := sys->pread(timefd, buf, len buf, big 0);
+	if(n <= 0)
+		return big 0;
+	return big string buf[0:n] * big 1000;
+}