shithub: riscv

Info  •  Files  •  Log  •  Branches

listen(1): implement one-shot mode flag for listen1 (thanks kivik)

--- a/sys/man/8/listen

+++ b/sys/man/8/listen

@@ -18,7 +18,7 @@

 .PP

 .B aux/listen1

 [

-.B -tv

+.B -1tv

 ]

 .RB [ -p

 .IR maxprocs ]

@@ -237,7 +237,7 @@

 .\" write out this way so automatic programs

 .\" don't try to make it into a real man page reference.

 \fIlisten\fR(1).

-announces on

+It announces on

 .IR address ,

 running

 .I cmd

@@ -254,6 +254,10 @@

 is to become

 .B none

 before listening.

+Option

+.B -1

+arms a one-shot listener; it terminates listen1

+upon receiving a single call.

 Option

 .B -v

 causes verbose logging on standard output.

--- a/sys/src/cmd/aux/listen1.c

+++ b/sys/src/cmd/aux/listen1.c

@@ -5,12 +5,13 @@

 int maxprocs;

 int verbose;

 int trusted;

+int oneshot;

 char *nsfile;

 void

 usage(void)

 {

-	fprint(2, "usage: listen1 [-tv] [-p maxprocs] [-n namespace] address cmd args...\n");

+	fprint(2, "usage: listen1 [-1tv] [-p maxprocs] [-n namespace] address cmd args...\n");

 	exits("usage");

 }

@@ -61,6 +62,9 @@

 	ARGBEGIN{

 	default:

 		usage();

+	case '1':

+		oneshot = 1;

+		break;

 	case 't':

 		trusted = 1;

 		break;

@@ -122,41 +126,47 @@

 		if(nctl < 0)

 			sysfatal("listen %s: %r", argv[0]);

+		if(!oneshot)

 		switch(rfork(RFFDG|RFPROC|RFMEM|RFENVG|RFNAMEG|RFNOTEG|RFREND|nowait)){

+		case 0:

+			break;

 		case -1:

 			reject(nctl, ndir, "host overloaded");

 			close(nctl);

 			continue;

-		case 0:

-			fd = accept(nctl, ndir);

-			if(fd < 0){

-				fprint(2, "accept %s: can't open  %s/data: %r\n",

-					argv[0], ndir);

-				_exits(0);

-			}

-			print("incoming call for %s from %s in %s\n", argv[0],

-				remoteaddr(ndir), ndir);

-			fprint(nctl, "keepalive");

-			close(ctl);

-			close(nctl);

-			if(wfd >= 0)

-				close(wfd);

-			putenv("net", ndir);

-			snprint(data, sizeof data, "%s/data", ndir);

-			bind(data, "/dev/cons", MREPL);

-			dup(fd, 0);

-			dup(fd, 1);

-			/* dup(fd, 2); keep stderr */

-			close(fd);

-			exec(argv[1], argv+1);

-			if(argv[1][0] != '/')

-				exec(smprint("/bin/%s", argv[1]), argv+1);

-			fprint(2, "%s: exec: %r\n", argv0);

-			exits(nil);

 		default:

 			close(nctl);

 			procs++;

-			break;

+			continue;

 		}

+

+		fd = accept(nctl, ndir);

+		if(fd < 0){

+			fprint(2, "accept %s: can't open  %s/data: %r\n", argv[0], ndir);

+			if(oneshot){

+				close(nctl);

+				continue;

+			}

+			exits("accept");

+		}

+

+		print("incoming call for %s from %s in %s\n", argv[0], remoteaddr(ndir), ndir);

+		fprint(nctl, "keepalive");

+		close(ctl);

+		close(nctl);

+		if(wfd >= 0)

+			close(wfd);

+		putenv("net", ndir);

+		snprint(data, sizeof data, "%s/data", ndir);

+		bind(data, "/dev/cons", MREPL);

+		dup(fd, 0);

+		dup(fd, 1);

+		/* dup(fd, 2); keep stderr */

+		close(fd);

+		exec(argv[1], argv+1);

+		if(argv[1][0] != '/')

+			exec(smprint("/bin/%s", argv[1]), argv+1);

+		fprint(2, "%s: exec: %r\n", argv0);

+		exits("exec");

 	}

 }