From: Todd C. Miller <Todd.Miller@courtesan.com>
Date: Sun, 20 Sep 2009 13:51:51 +0000 (+0000)
Subject: Go back to dropping out of the select() loop when the process dies; Linux
X-Git-Tag: SUDO_1_7_3~269
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7bb38284b05fa4edaa62cca20b183801e420542d;p=sudo

Go back to dropping out of the select() loop when the process dies; Linux
ptys apparently don't behave the same as BSD in regards to select().
No need to flush remaining output to the transcript, only to stdout.
Add back code to check the master pty for additional data when we exit
the main select loop.
---

diff --git a/script.c b/script.c
index 89faa8fbf..13a96d2b1 100644
--- a/script.c
+++ b/script.c
@@ -386,7 +386,7 @@ script_execv(path, argv)
 	sizeof(fd_mask));
     zero_bytes(&input, sizeof(input));
     zero_bytes(&output, sizeof(output));
-    for (;;) {
+    while (alive) {
 	if (input.off == input.len)
 	    input.off = input.len = 0;
 	if (output.off == output.len)
@@ -394,16 +394,14 @@ script_execv(path, argv)
 
 	zero_bytes(fdsw, howmany(script_fds[SFD_MASTER] + 1, NFDBITS) * sizeof(fd_mask));
 	zero_bytes(fdsr, howmany(script_fds[SFD_MASTER] + 1, NFDBITS) * sizeof(fd_mask));
+	if (input.len != sizeof(input.buf))
+	    FD_SET(STDIN_FILENO, fdsr);
 	if (output.len != sizeof(output.buf))
 	    FD_SET(script_fds[SFD_MASTER], fdsr);
 	if (output.len > output.off)
 	    FD_SET(STDOUT_FILENO, fdsw);
-	if (alive) {
-	    if (input.len != sizeof(input.buf))
-		FD_SET(STDIN_FILENO, fdsr);
-	    if (input.len > input.off)
-		FD_SET(script_fds[SFD_MASTER], fdsw);
-	}
+	if (input.len > input.off)
+	    FD_SET(script_fds[SFD_MASTER], fdsw);
 
 	nready = select(script_fds[SFD_MASTER] + 1, fdsr, fdsw, NULL, NULL);
 	if (nready == -1) {
@@ -469,14 +467,28 @@ script_execv(path, argv)
 	}
     }
 
-    /* Flush any remaining output. */
+    /* Flush any remaining output to stdout (already updated output file). */
     n = fcntl(STDOUT_FILENO, F_GETFL, 0);
     if (n != -1) {
 	n &= ~O_NONBLOCK;
 	(void) fcntl(STDOUT_FILENO, F_SETFL, n);
     }
-    if (output.len > output.off) {
-	log_output(&output, output.len - output.off, &then, &now, ofile, tfile);
+    do {
+	n = write(STDOUT_FILENO, output.buf + output.off,
+	    output.len - output.off);
+	if (n <= 0)
+	    break;
+	output.off += n;
+    } while (output.len > output.off);
+
+    /* Make sure there is no output remaining on the master pty. */
+    for (;;) {
+	n = read(script_fds[SFD_MASTER], output.buf, sizeof(output.buf));
+	if (n <= 0)
+	    break;
+	output.off = 0;
+	output.len = n;
+	log_output(&output, output.len, &then, &now, ofile, tfile);
 	do {
 	    n = write(STDOUT_FILENO, output.buf + output.off,
 		output.len - output.off);
@@ -485,6 +497,7 @@ script_execv(path, argv)
 	    output.off += n;
 	} while (output.len > output.off);
     }
+
     term_restore(STDIN_FILENO);
 
     if (WIFEXITED(child_status))