[src/trunk]: src/lib/libc/gen keep track if we have the file opened as readon...

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

details:   https://anonhg.NetBSD.org/src/rev/c3ac0c5f19aa
branches:  trunk
changeset: 543497:c3ac0c5f19aa
user:      christos <christos%NetBSD.org@localhost>
date:      Wed Feb 26 19:23:25 2003 +0000

description:
keep track if we have the file opened as readonly or readwrite, so that
we don't need to call update_utmp, if our euid has changed, but we still
have a write reference to the file. Solves problem with chrooting processes.

diffstat:

 lib/libc/gen/utmpx.c |  22 +++++++++++++++-------
 1 files changed, 15 insertions(+), 7 deletions(-)

diffs (73 lines):

diff -r 5b3b468d3d27 -r c3ac0c5f19aa lib/libc/gen/utmpx.c
--- a/lib/libc/gen/utmpx.c      Wed Feb 26 19:10:28 2003 +0000
+++ b/lib/libc/gen/utmpx.c      Wed Feb 26 19:23:25 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: utmpx.c,v 1.16 2002/11/26 16:52:07 christos Exp $       */
+/*     $NetBSD: utmpx.c,v 1.17 2003/02/26 19:23:25 christos Exp $       */
 
 /*-
  * Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -38,7 +38,7 @@
 #include <sys/cdefs.h>
 
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: utmpx.c,v 1.16 2002/11/26 16:52:07 christos Exp $");
+__RCSID("$NetBSD: utmpx.c,v 1.17 2003/02/26 19:23:25 christos Exp $");
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/types.h>
@@ -61,6 +61,7 @@
 #include <db.h>
 
 static FILE *fp;
+static int readonly = 0;
 static struct utmpx ut;
 static char utfile[MAXPATHLEN] = _PATH_UTMPX;
 static char llfile[MAXPATHLEN] = _PATH_LASTLOGX;
@@ -88,6 +89,7 @@
        if (fp != NULL) {
                (void)fclose(fp);
                fp = NULL;
+               readonly = 0;
        }
 }
 
@@ -100,9 +102,13 @@
                struct stat st;
 
                if ((fp = fopen(utfile, "r+")) == NULL)
-                       if ((fp = fopen(utfile, "w+")) == NULL)
+                       if ((fp = fopen(utfile, "w+")) == NULL) {
                                if ((fp = fopen(utfile, "r")) == NULL)
                                        goto fail;
+                               else
+                                       readonly = 1;
+                       }
+                                       
 
                /* get file size in order to check if new file */
                if (fstat(fileno(fp), &st) == -1)
@@ -216,17 +222,19 @@
 
        _DIAGASSERT(utx != NULL);
 
-       if (strcmp(_PATH_UTMPX, utfile) == 0 && geteuid() != 0)
-               return utmp_update(utx);
-
        if (utx == NULL)
                return NULL;
 
+       if (strcmp(_PATH_UTMPX, utfile) == 0)
+               if ((fp != NULL && readonly) || (fp == NULL && geteuid() != 0))
+                       return utmp_update(utx);
+
+
        (void)memcpy(&temp, utx, sizeof(temp));
 
        if (fp == NULL) {
                (void)getutxent();
-               if (fp == NULL)
+               if (fp == NULL || readonly)
                        return NULL;
        }