upstream: notify user immediately when underlying ssh process dies;

patch from Thomas Kuthan in bz2719; ok dtucker@

OpenBSD-Commit-ID: 78fac88c2f08054d1fc5162c43c24162b131cf78

1 files changed, 20 insertions, 1 deletions

diff --git a/sftp.c b/sftp.c
index 279f7d46e..da81897e4 100644
--- a/sftp.c
+++ b/sftp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp.c,v 1.183 2018/04/10 00:10:49 djm Exp $ */
+/* $OpenBSD: sftp.c,v 1.184 2018/04/13 05:04:12 djm Exp $ */
 /*
  * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
  *
@@ -253,6 +253,23 @@ cmd_interrupt(int signo)
         errno = olderrno;
 }
 
+/*ARGSUSED*/
+static void
+sigchld_handler(int sig)
+{
+        int save_errno = errno;
+        pid_t pid;
+        const char msg[] = "\rConnection closed.  \n";
+
+        /* Report if ssh transport process dies. */
+        while ((pid = waitpid(sshpid, NULL, WNOHANG)) == -1 && errno == EINTR)
+                continue;
+        if (pid == sshpid)
+                (void)write(STDERR_FILENO, msg, sizeof(msg) - 1);
+
+        errno = save_errno;
+}
+
 static void
 help(void)
 {
@@ -2227,6 +2244,7 @@ interactive_loop(struct sftp_conn *conn, char *file1, char *file2)
                 if (err != 0)
                         break;
         }
+        signal(SIGCHLD, SIG_DFL);
         free(remote_path);
         free(startdir);
         free(conn);
@@ -2296,6 +2314,7 @@ connect_to_server(char *path, char **args, int *in, int *out)
         signal(SIGTSTP, suspchild);
         signal(SIGTTIN, suspchild);
         signal(SIGTTOU, suspchild);
+        signal(SIGCHLD, sigchld_handler);
         close(c_in);
         close(c_out);
 }