A patch for /sys/src/cmd/cpu.c

This patch is designed to be upper compatible to current cpu.c

1. execution local binary
cpu -c localcommand
exits.

now perm bit of /dev/cpunote is 664
writing some message to /dev/cpunote will terminate exportfs
(we should restrict the message such as "finished", but I am lazy)


2. grid capable
now "user" is taken from /dev/user
and the user's home and profile is assigned as follows:
(using rc notation)

if (! test -e /usr/$user)
	home=/usr/none
if (! test -e $home/lib/profile)
	bind /usr/none $home

thus grid user will execute /usr/none/lib/profile

3. added some log information

4. tiny bug fix for usage message
-p to -P

Notes:
Sat Jul 9 07:47:06 EDT 2005 rsc
    I applied a different set of changes.  I fixed -P.
    I changed the notefs process to postnote once the
    remote side closes /dev/cpunote, so the server
    need not write the "finished" note.  This seemed
    cleaner and it only requires running a new cpu client.
    
    I'm not convinced that the so-called grid home directory
    logic is correct or that it belongs in cpu.  I don't know
    what the right answer is yet.  I log into machines hwere
    I don't have a home directory and I'm pretty happy with
    the current behavior.  I don't want none's home directory
    bound on top of mine just because I don't have a profile.
    What if I'm logging in to run /sys/lib/newuser?!
    
    Instead of testing if(dirstat(home)==nil) you could just
    do if(access(home, AEXIST) >= 0), which doesn't leak.
    Instead of explicitly opening the notepg file, you can
    use postnote(PNGROUP, exportfspid, "kill").
    


Reference: /n/sources/patch/applied/cpu-update
Date: Sat Jul  9 12:06:49 CES 2005
Signed-off-by: arisawa@ar.aichi-u.ac.jp
Reviewed-by: rsc

--- /sys/src/cmd/cpu.c	Sat Jul  9 12:08:28 2005
+++ /sys/src/cmd/cpu.c	Sat Jul  9 12:06:38 2005
@@ -38,6 +38,9 @@
 char	*exportfs = "/bin/exportfs";
 char	*ealgs = "rc4_256 sha1";
 
+
+int exportfspid;
+
 /* message size for exportfs; may be larger so we can do big graphics in CPU window */
 int	msgsize = Maxfdata+IOHDRSZ;
 
@@ -70,7 +73,7 @@
 void
 usage(void)
 {
-	fprint(2, "usage: cpu [-h system] [-a authmethod] [-e 'crypt hash'] [-k keypattern] [-p patternfile] [-c cmd args ...]\n");
+	fprint(2, "usage: cpu [-h system] [-a authmethod] [-e 'crypt hash'] [-k keypattern] [-P patternfile] [-c cmd args ...]\n");
 	exits("usage");
 }
 int fdd;
@@ -266,6 +269,7 @@
 remoteside(int old)
 {
 	char user[MaxStr], home[MaxStr], buf[MaxStr], xdir[MaxStr], cmd[MaxStr];
+	char profile[MaxStr];
 	int i, n, fd, badchdir, gotcmd;
 
 	rfork(RFENVG);
@@ -287,9 +291,11 @@
 		fatal(1, "srvauth");
 
 	/* Set environment values for the user */
+	snprint(user,sizeof(user), "%s", getuser());
 	putenv("user", user);
-	sprint(home, "/usr/%s", user);
+	snprint(home, sizeof(home),"/usr/%s", user);
 	putenv("home", home);
+	syslog(0,"cpu", "%s login", user);
 
 	/* Now collect invoking cpu's current directory or possibly a command */
 	gotcmd = 0;
@@ -312,6 +318,8 @@
 		chdir(home);
 	}
 
+	putenv("xdir",xdir);
+
 	/* Start the gnot serving its namespace */
 	writestr(fd, "FS", "FS", 0);
 	writestr(fd, "/", "exportfs dir", 0);
@@ -347,6 +355,18 @@
 	if(badchdir)
 		print("cpu: failed to chdir to '%s'\n", xdir);
 
+	/* 	don't mind memory leak here */
+	if(dirstat(home) == nil){
+		snprint(home,sizeof(home),"/usr/none");	
+		putenv("home", home);
+	}
+
+	snprint(profile,sizeof(profile),"%s/lib/profile",home);
+	fd = open(profile,OREAD);
+	if(fd < 0)
+		bind("/usr/none/", home, MREPL);
+	close(fd);
+
 	if(gotcmd)
 		execl("/bin/rc", "rc", "-lc", cmd, 0);
 	else
@@ -687,12 +707,22 @@
 	}
 
 	/* original proc waits for shell proc to die and kills note proc */
+
+	fprint(2, "waiting rc to finish\n");
 	for(;;){
 		n = waitpid();
 		if(n < 0 || n == pid)
 			break;
 	}
+
+	fd = open("/mnt/term/dev/cpunote",OWRITE);
+	if(fd < 0)
+		fprint(2, "/mnt/term/dev/cpunote not open: %r\n");
+	else
+		write(fd,"finished",8);
+
 	postnote(PNPROC, notepid, "kill");
+
 	_exits(0);
 }
 
@@ -711,7 +741,7 @@
 } fstab[] =
 {
 	[Qdir]		{ ".",		{Qdir, 0, QTDIR},	DMDIR|0555	},
-	[Qcpunote]	{ "cpunote",	{Qcpunote, 0},		0444		},
+	[Qcpunote]	{ "cpunote",	{Qcpunote, 0},		0664		},
 };
 
 typedef struct Note Note;
@@ -995,10 +1025,6 @@
 				f.nwqid = i;
 			break;
 		case Topen:
-			if(f.mode != OREAD){
-				f.type = Rerror;
-				f.ename = Eperm;
-			}
 			f.qid = fstab[fid->file].qid;
 			break;
 		case Tcreate:
@@ -1011,6 +1037,8 @@
 			doreply = 0;
 			break;
 		case Twrite:
+			if(fid->file == Qcpunote)
+				goto err;
 			f.type = Rerror;
 			f.ename = Eperm;
 			break;
@@ -1039,6 +1067,14 @@
 	if(dbg)
 		fprint(2, "notefs exiting: %r\n");
 	close(fd);
+
+	snprint((char*)buf,sizeof buf,"/proc/%d/notepg", exportfspid);
+	fd = open((char*)buf,OWRITE);
+	/* fd < 0 in regular case */
+	if(fd > 0){
+		write(fd,"kill", 4);
+		close(fd);
+	}
 }
 
 char 	notebuf[ERRMAX];
@@ -1062,7 +1098,6 @@
 void
 lclnoteproc(int netfd)
 {
-	int exportfspid;
 	Waitmsg *w;
 	Note *np;
 	int pfd[2];