From: Karel Zak <kzak@redhat.com>
Date: Thu, 8 Mar 2007 22:22:06 +0000 (+0100)
Subject: login: update 32bit utmp correctly on 64bit system
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=75d4dbb0d7d7937f0f5f464c3bd803d4191a6c0e;p=util-linux

login: update 32bit utmp correctly on 64bit system

On 64-bit platforms such as x86_64, glibc is usually built with 32-bit
compatibility for various structures. One of them is utmp.

What this means is that gettimeofday(&ut.ut_tv, NULL) on x86_64 will
end up overwriting the first parts of ut_addr_v6, leading to garbage
in the utmp file.

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/login-utils/login.c b/login-utils/login.c
index 1715015d..d5ec1fc0 100644
--- a/login-utils/login.c
+++ b/login-utils/login.c
@@ -256,6 +256,7 @@ consoletty(int fd) {
 static void
 logbtmp(const char *line, const char *username, const char *hostname) {
 	struct utmp ut;
+	struct timeval tv;
 
 	memset(&ut, 0, sizeof(ut));
 
@@ -266,7 +267,9 @@ logbtmp(const char *line, const char *username, const char *hostname) {
 	xstrncpy(ut.ut_line, line, sizeof(ut.ut_line));
 
 #if defined(_HAVE_UT_TV)	    /* in <utmpbits.h> included by <utmp.h> */
-	gettimeofday(&ut.ut_tv, NULL);
+	gettimeofday(&tv, NULL);
+	ut.ut_tv.tv_sec = tv.tv_sec;
+	ut.ut_tv.tv_usec = tv.tv_usec;
 #else
 	{
 		time_t t;
@@ -833,6 +836,7 @@ main(int argc, char **argv)
     {
 	struct utmp ut;
 	struct utmp *utp;
+	struct timeval tv;
 	
 	utmpname(_PATH_UTMP);
 	setutent();
@@ -872,7 +876,9 @@ Michael Riepe <michael@stud.uni-hannover.de>
 	strncpy(ut.ut_user, username, sizeof(ut.ut_user));
 	xstrncpy(ut.ut_line, tty_name, sizeof(ut.ut_line));
 #ifdef _HAVE_UT_TV		/* in <utmpbits.h> included by <utmp.h> */
-	gettimeofday(&ut.ut_tv, NULL);
+	gettimeofday(&tv, NULL);
+	ut.ut_tv.tv_sec = tv.tv_sec;
+	ut.ut_tv.tv_usec = tv.tv_usec;
 #else
 	{
 	    time_t t;