Date: Sun, 10 Oct 1999 20:21:53 +0100 (BST) From: iedowse@maths.tcd.ie To: FreeBSD-gnats-submit@freebsd.org Subject: bin/14250: restore(8) can loop if tty goes away or with -y option Message-ID: <199910102021.aa25552@walton.maths.tcd.ie>
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>Number: 14250
>Category: bin
>Synopsis: restore(8) can loop if tty goes away or with -y option
>Confidential: no
>Severity: serious
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sun Oct 10 12:30:01 PDT 1999
>Closed-Date:
>Last-Modified:
>Originator: Ian Dowse
>Release: FreeBSD 3.3-STABLE i386
>Organization:
School of Mathematics,
Trinity College Dublin
>Environment:
All versions of FreeBSD.
>Description:
restore(8) can get stuck in a loop under certain conditions:
- If run in the background, and the user logs out while it is
still running, restore may start looping at the point where it
asks if the permissions on "." should be set. It does check for
tty EOF conditions with feof(3), but some types of tty errors
generate an EIO error rather than an end-of-file condition.
As well as looping, restore also fails to set permissions on
most of the directories it has extracted.
- If the '-y' option is specified, or an end-of-file or error
condition occurs on the tty, a truncated pipe input will
result in an infinite loop of 'Changing volumes on pipe input?'
messages. This problem is related to that in PR bin/4176.
>How-To-Repeat:
- Run the command:
cat dumpfile | restore xf - &
and then log out (I used tcsh - but this may not be important).
The restore process will loop when it gets to the end, and not
set all permissions correctly.
- Truncate a dump file, and run the command:
cat dumpfile | restore xyf -
>Fix:
Apply the following patches in src/sbin/restore:
--- tape.c 1999/08/28 00:14:08 1.16
+++ tape.c 1999/10/10 18:36:34
@@ -305,8 +305,12 @@
gettingfile = 0;
}
if (pipein) {
- if (nextvol != 1)
+ if (nextvol != 1) {
panic("Changing volumes on pipe input?\n");
+ /* Avoid looping if we weren't asking a tty */
+ if (yflag || ferror(terminal) || feof(terminal))
+ done(1);
+ }
if (volno == 1)
return;
goto gethdr;
@@ -343,10 +347,9 @@
do {
fprintf(stderr, "Specify next volume #: ");
(void) fflush(stderr);
- (void) fgets(buf, BUFSIZ, terminal);
- } while (!feof(terminal) && buf[0] == '\n');
- if (feof(terminal))
- done(1);
+ if (fgets(buf, BUFSIZ, terminal) == NULL)
+ done(1);
+ } while (buf[0] == '\n');
newvol = atoi(buf);
if (newvol <= 0) {
fprintf(stderr,
@@ -362,8 +365,7 @@
fprintf(stderr, "Enter ``none'' if there are no more tapes\n");
fprintf(stderr, "otherwise enter tape name (default: %s) ", magtape);
(void) fflush(stderr);
- (void) fgets(buf, BUFSIZ, terminal);
- if (feof(terminal))
+ if (fgets(buf, BUFSIZ, terminal) == NULL)
done(1);
if (!strcmp(buf, "none\n")) {
terminateinput();
--- utilities.c 1999/08/28 00:14:09 1.8
+++ utilities.c 1999/10/10 18:06:01
@@ -405,14 +405,14 @@
reply(question)
char *question;
{
- char c;
+ int c;
do {
fprintf(stderr, "%s? [yn] ", question);
(void) fflush(stderr);
c = getc(terminal);
while (c != '\n' && getc(terminal) != '\n')
- if (feof(terminal))
+ if (c == EOF)
return (FAIL);
} while (c != 'y' && c != 'n');
if (c == 'y')
--- interactive.c 1999/08/28 00:14:05 1.8
+++ interactive.c 1999/10/10 18:34:29
@@ -325,12 +325,11 @@
do {
fprintf(stderr, "restore > ");
(void) fflush(stderr);
- (void) fgets(input, BUFSIZ, terminal);
- } while (!feof(terminal) && input[0] == '\n');
- if (feof(terminal)) {
- (void) strcpy(cmd, "quit");
- return;
- }
+ if (fgets(input, BUFSIZ, terminal) == NULL) {
+ (void) strcpy(cmd, "quit");
+ return;
+ }
+ } while (input[0] == '\n');
for (cp = &input[strlen(input) - 2]; *cp == ' ' || *cp == '\t'; cp--)
/* trim off trailing white space and newline */;
*++cp = '\0';
>Release-Note:
>Audit-Trail:
>Unformatted:
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