emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

rdate: make it do something remotely sane, facing 32-bit time overflow

Browse Source 
function                                             old     new   delta
rdate_main                                           251     254      +3
packed_usage                                       31029   31023      -6

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2017-01-20 16:03:48 +01:00
parent 19e695ebad
commit 179e88bec9
2 changed files with 27 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
networking/inetd.c
View File

@ -1677,7 +1677,7 @@ static uint32_t machtime(void)
struct timeval tv; struct timeval tv;
gettimeofday(&tv, NULL); gettimeofday(&tv, NULL);
return htonl((uint32_t)(tv.tv_sec + 2208988800)); return htonl((uint32_t)(tv.tv_sec + 2208988800U));
} }
/* ARGSUSED */ /* ARGSUSED */
static void FAST_FUNC machtime_stream(int s, servtab_t *sep UNUSED_PARAM) static void FAST_FUNC machtime_stream(int s, servtab_t *sep UNUSED_PARAM)

31
util-linux/rdate.c
View File

@ -21,11 +21,11 @@
//kbuild:lib-$(CONFIG_RDATE) += rdate.o //kbuild:lib-$(CONFIG_RDATE) += rdate.o
//usage:#define rdate_trivial_usage //usage:#define rdate_trivial_usage
//usage: "[-sp] HOST" //usage: "[-s/-p] HOST"
//usage:#define rdate_full_usage "\n\n" //usage:#define rdate_full_usage "\n\n"
//usage: "Get and possibly set system time from a remote HOST\n" //usage: "Set and print time from HOST using RFC 868\n"
//usage: "\n -s Set system time (default)" //usage: "\n -s Only set system time"
//usage: "\n -p Print time" //usage: "\n -p Only print time"
#include "libbb.h" #include "libbb.h"
@ -58,8 +58,22 @@ static time_t askremotedate(const char *host)
* the RFC 868 time 2,208,988,800 corresponds to 00:00 1 Jan 1970 GMT * the RFC 868 time 2,208,988,800 corresponds to 00:00 1 Jan 1970 GMT
* Subtract the RFC 868 time to get Linux epoch. * Subtract the RFC 868 time to get Linux epoch.
*/ */
nett = ntohl(nett) - RFC_868_BIAS;
return ntohl(nett) - RFC_868_BIAS; if (sizeof(time_t) > 4) {
/* Now we have 32-bit lsb of a wider time_t
* Imagine that nett = 0x00000001,
* current time cur = 0x123ffffffff.
* Assuming our time is not some 40 years off,
* remote time must be 0x12400000001.
* Need to adjust out time by (int32_t)(nett - cur).
*/
time_t cur = time(NULL);
int32_t adjust = (int32_t)(nett - (uint32_t)cur);
return cur + adjust;
}
/* This is not going to work, but what can we do */
return (time_t)nett;
} }
int rdate_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int rdate_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@ -73,6 +87,13 @@ int rdate_main(int argc UNUSED_PARAM, char **argv)
remote_time = askremotedate(argv[optind]); remote_time = askremotedate(argv[optind]);
/* Manpages of various Unixes are confusing. What happens is:
* (no opts) set and print time
* -s: set time ("do not print the time")
* -p: print time ("do not set, just print the remote time")
* -sp: print time (that's what we do, not sure this is right)
*/
if (!(flags & 2)) { /* no -p (-s may be present) */ if (!(flags & 2)) { /* no -p (-s may be present) */
time_t current_time; time_t current_time;