[src/trunk]: src/usr.bin/rsh Fix signal delivery to remote process; As descri...

[enami <enami%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/c656ded25c98
branches:  trunk
changeset: 329770:c656ded25c98
user:      enami <enami%NetBSD.org@localhost>
date:      Sun Jun 08 02:44:15 2014 +0000

description:
Fix signal delivery to remote process; As described in rcmd(3), a signal
is delivered to the remote process via the secondary channel.  So,
the backend driver, rcmd(1), is responsible to watch the file descriptor 2
and transfer the data to the remote process, rather than receiving signal
by itself.  Previously, signal generated by tty was sent since rcmd was
incorrectly generated the data, but, for example, signal sent to rsh command
by kill command was ignored.

diffstat:

 usr.bin/rsh/rsh.c |  44 +++++++++++++++++++++++++++++++++-----------
 1 files changed, 33 insertions(+), 11 deletions(-)

diffs (118 lines):

diff -r 2a2ebb509874 -r c656ded25c98 usr.bin/rsh/rsh.c
--- a/usr.bin/rsh/rsh.c Sun Jun 08 02:23:46 2014 +0000
+++ b/usr.bin/rsh/rsh.c Sun Jun 08 02:44:15 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rsh.c,v 1.35 2014/06/08 02:02:41 enami Exp $   */
+/*     $NetBSD: rsh.c,v 1.36 2014/06/08 02:44:15 enami Exp $   */
 
 /*-
  * Copyright (c) 1983, 1990, 1993, 1994
@@ -39,7 +39,7 @@
 #if 0
 static char sccsid[] = "@(#)rsh.c      8.4 (Berkeley) 4/29/95";
 #else
-__RCSID("$NetBSD: rsh.c,v 1.35 2014/06/08 02:02:41 enami Exp $");
+__RCSID("$NetBSD: rsh.c,v 1.36 2014/06/08 02:44:15 enami Exp $");
 #endif
 #endif /* not lint */
 
@@ -76,7 +76,9 @@
 static int sigs[] = { SIGINT, SIGTERM, SIGQUIT };
 
 static char   *copyargs(char **);
+#ifndef IN_RCMD
 static void    sendsig(int);
+#endif
 static int     checkfd(struct pollfd *, int);
 static void    talk(int, sigset_t *, pid_t, int);
 __dead static void     usage(void);
@@ -265,6 +267,7 @@
 
        (void)sigprocmask(SIG_BLOCK, &nset, &oset);
 
+#ifndef IN_RCMD
        for (i = 0; i < sizeof(sigs) / sizeof(sigs[0]); i++) {
                struct sigaction sa;
 
@@ -273,6 +276,7 @@
                        (void)sigaction(sigs[i], &sa, NULL);
                }
        }
+#endif
 
        if (!nflag) {
                pid = fork();
@@ -329,7 +333,7 @@
 talk(int nflag, sigset_t *oset, __pid_t pid, int rem)
 {
        int nr, nw, nfds;
-       struct pollfd fds[2], *fdp = &fds[0];
+       struct pollfd fds[3], *fdp = &fds[0];
        char *bp, buf[BUFSIZ];
 
        if (!nflag && pid == 0) {
@@ -385,31 +389,48 @@
                exit(0);
        }
 
+#ifdef IN_RCMD
+       fdp = &fds[0];
+       nfds = 3;
+       fds[0].events = POLLIN|POLLNVAL|POLLERR|POLLHUP;
+       fds[0].fd = 2;
+#else
        (void)sigprocmask(SIG_SETMASK, oset, NULL);
-       fds[0].events = fds[1].events = POLLIN|POLLNVAL|POLLERR|POLLHUP;
-       fds[0].fd = remerr;
-       fds[1].fd = rem;
-       fdp = &fds[0];
+       fdp = &fds[1];
        nfds = 2;
+       fds[0].events = 0;
+#endif
+       fds[1].events = fds[2].events = POLLIN|POLLNVAL|POLLERR|POLLHUP;
+       fds[1].fd = remerr;
+       fds[2].fd = rem;
        do {
                if (poll(fdp, nfds, INFTIM) == -1) {
                        if (errno != EINTR)
                                err(1, "poll");
                        continue;
                }
-               if (fds[0].events != 0 && checkfd(&fds[0], 2) == -1) {
+               if ((fds[1].events != 0 && checkfd(&fds[1], 2) == -1)
+#ifdef IN_RCMD
+                   || (fds[0].events != 0 && checkfd(&fds[0], remerr) == -1)
+#endif
+                   ) {
+                       nfds--;
+                       fds[1].events = 0;
+#ifdef IN_RCMD
                        nfds--;
                        fds[0].events = 0;
-                       fdp = &fds[1];
+#endif
+                       fdp = &fds[2];
                }
-               if (fds[1].events != 0 && checkfd(&fds[1], 1) == -1) {
+               if (fds[2].events != 0 && checkfd(&fds[2], 1) == -1) {
                        nfds--;
-                       fds[1].events = 0;
+                       fds[2].events = 0;
                }
        }
        while (nfds);
 }
 
+#ifndef IN_RCMD
 static void
 sendsig(int sig)
 {
@@ -418,6 +439,7 @@
        signo = sig;
        (void)write(remerr, &signo, 1);
 }
+#endif
 
 
 static char *