difos/package/network/services/ppp/patches/206-compensate_time_change.patch
DENG Qingfang 983605e61f pppd: update to 2.4.8
78cd384 Update README and patchlevel.h for 2.4.8 release
5d03403 pppd: Avoid use of strnlen (and strlen) in vslprintf
a1e950a pppd: Fix IPv6 default route code for Solaris
ca5e61b plugins/rp-pppoe: Make tag parsing loop condition more accurate
c10c3c7 pppd: Make sure word read from options file is null-terminated
b311e98 pppd: Limit memory accessed by string formats with max length specified
3ea9de9 pppd: Eliminate some more compiler warnings
57edb1a pppd: Include time.h header before using time_t
09f695f pppd: Don't free static string
03104ba pppd.h: Add missing headers
388597e pppd: Add defaultroute6 and related options
66ce4ba pppd: Avoid declarations within statements in main.c
5637180 pppd: Fix `ifname` option in case of multilink (#105)
d00f8a0 pppd: Fix variable reference syntax in Makefile.linux
b6b4d28 pppd: Check tdb pointer before closing

Signed-off-by: DENG Qingfang <dengqf6@mail2.sysu.edu.cn>
2020-01-05 19:36:45 +01:00

94 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 <jo@mein.io>
--- a/pppd/main.c
+++ b/pppd/main.c
@@ -89,6 +89,7 @@
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
+#include <sys/sysinfo.h>
#include "pppd.h"
#include "magic.h"
@@ -226,6 +227,7 @@ 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));
@@ -525,6 +527,7 @@ main(argc, argv)
info("Starting link");
}
+ check_time();
gettimeofday(&start_time, NULL);
script_unsetenv("CONNECT_TIME");
script_unsetenv("BYTES_SENT");
@@ -1274,6 +1277,36 @@ 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.
@@ -1344,6 +1377,8 @@ calltimeout()
{
struct callout *p;
+ check_time();
+
while (callout != NULL) {
p = callout;
@@ -1371,6 +1406,8 @@ timeleft(tvp)
{
if (callout == NULL)
return NULL;
+
+ check_time();
gettimeofday(&timenow, NULL);
tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;