mirror of https://github.com/hak5/openwrt.git
95 lines
2.3 KiB
Diff
95 lines
2.3 KiB
Diff
pppd: Watch out for time warps
|
|
|
|
On many embedded systems there is no battery backed RTC and a proper system
|
|
time only becomes available through NTP after establishing a connection.
|
|
|
|
When the clock suddenly jumps forward, the internal accounting (connect time)
|
|
is confused resulting in unreliable data.
|
|
|
|
This patch implements periodic clock checking to look for time warps, if one
|
|
is detected, the internal counters are adjusted accordingly.
|
|
|
|
Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>
|
|
|
|
--- a/pppd/main.c
|
|
+++ b/pppd/main.c
|
|
@@ -90,6 +90,7 @@
|
|
#include <sys/socket.h>
|
|
#include <netinet/in.h>
|
|
#include <arpa/inet.h>
|
|
+#include <sys/sysinfo.h>
|
|
|
|
#include "pppd.h"
|
|
#include "magic.h"
|
|
@@ -228,6 +229,7 @@ static struct subprocess *children;
|
|
|
|
/* Prototypes for procedures local to this file. */
|
|
|
|
+static void check_time(void);
|
|
static void setup_signals __P((void));
|
|
static void create_pidfile __P((int pid));
|
|
static void create_linkpidfile __P((int pid));
|
|
@@ -535,6 +537,7 @@ main(argc, argv)
|
|
info("Starting link");
|
|
}
|
|
|
|
+ check_time();
|
|
gettimeofday(&start_time, NULL);
|
|
script_unsetenv("CONNECT_TIME");
|
|
script_unsetenv("BYTES_SENT");
|
|
@@ -1267,6 +1270,36 @@ struct callout {
|
|
|
|
static struct callout *callout = NULL; /* Callout list */
|
|
static struct timeval timenow; /* Current time */
|
|
+static long uptime_diff = 0;
|
|
+static int uptime_diff_set = 0;
|
|
+
|
|
+static void check_time(void)
|
|
+{
|
|
+ long new_diff;
|
|
+ struct timeval t;
|
|
+ struct sysinfo i;
|
|
+ struct callout *p;
|
|
+
|
|
+ gettimeofday(&t, NULL);
|
|
+ sysinfo(&i);
|
|
+ new_diff = t.tv_sec - i.uptime;
|
|
+
|
|
+ if (!uptime_diff_set) {
|
|
+ uptime_diff = new_diff;
|
|
+ uptime_diff_set = 1;
|
|
+ return;
|
|
+ }
|
|
+
|
|
+ if ((new_diff - 5 > uptime_diff) || (new_diff + 5 < uptime_diff)) {
|
|
+ /* system time has changed, update counters and timeouts */
|
|
+ info("System time change detected.");
|
|
+ start_time.tv_sec += new_diff - uptime_diff;
|
|
+
|
|
+ for (p = callout; p != NULL; p = p->c_next)
|
|
+ p->c_time.tv_sec += new_diff - uptime_diff;
|
|
+ }
|
|
+ uptime_diff = new_diff;
|
|
+}
|
|
|
|
/*
|
|
* timeout - Schedule a timeout.
|
|
@@ -1337,6 +1370,8 @@ calltimeout()
|
|
{
|
|
struct callout *p;
|
|
|
|
+ check_time();
|
|
+
|
|
while (callout != NULL) {
|
|
p = callout;
|
|
|
|
@@ -1364,6 +1399,8 @@ timeleft(tvp)
|
|
{
|
|
if (callout == NULL)
|
|
return NULL;
|
|
+
|
|
+ check_time();
|
|
|
|
gettimeofday(&timenow, NULL);
|
|
tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
|