pppd: linux: use monotonic time if possible

gettimeofday() suffers from time jumps due ntp or any manual change,
so duration measurements and scheduling can not be accurate.
let's use monotonic time source instead, if available.

it's known glibc (< 2.3.4) & old uclibc don't provide CLOCK_MONOTONIC
denine, but kernel may have it supported. so, use clock_gettime()
with fallback to gettimeofday() if first call has failed.

several gettimeofday()/time() calls still have to be preserved for
debug, pseudoterminal timestamping and string formatting. all the
rest calls are replaced to new get_time() call.

solaris kept with gettimeofday() as before, corresponding get_time()
system implementation can be updated/added in any future.

Signed-off-by: Vladislav Grishenko <themiron@mail.ru>

diff --git a/pppd/Makefile.linux b/pppd/Makefile.linux
index 8d5ce99d92202c4326730393c0d9e56d327fbefe..2a05bc42492b4b2973653b05cc2007e9eb963238 100644 (file)
--- a/pppd/Makefile.linux
+++ b/pppd/Makefile.linux
@@ -33,7 +33,7 @@ endif
 # CC = gcc
 #
 COPTS = -O2 -pipe -Wall -g
-LIBS =
+LIBS = -lrt
 
 # Uncomment the next line to include support for Microsoft's
 # MS-CHAP authentication protocol.  Also, edit plugins/radius/Makefile.linux.

diff --git a/pppd/main.c b/pppd/main.c
index e09b6ffcce32bd06389d91da6276f24c1e009007..dccd78b28d07aacdf45a1da146ecbf439f99bf9e 100644 (file)
--- a/pppd/main.c
+++ b/pppd/main.c
@@ -522,7 +522,7 @@ main(argc, argv)
            info("Starting link");
        }
 
-       gettimeofday(&start_time, NULL);
+       get_time(&start_time);
        script_unsetenv("CONNECT_TIME");
        script_unsetenv("BYTES_SENT");
        script_unsetenv("BYTES_RCVD");
@@ -1216,7 +1216,7 @@ reset_link_stats(u)
 {
     if (!get_ppp_stats(u, &old_link_stats))
        return;
-    gettimeofday(&start_time, NULL);
+    get_time(&start_time);
 }
 
 /*
@@ -1230,7 +1230,7 @@ update_link_stats(u)
     char numbuf[32];
 
     if (!get_ppp_stats(u, &link_stats)
-       || gettimeofday(&now, NULL) < 0)
+       || get_time(&now) < 0)
        return;
     link_connect_time = now.tv_sec - start_time.tv_sec;
     link_stats_valid = 1;
@@ -1277,7 +1277,7 @@ timeout(func, arg, secs, usecs)
        fatal("Out of memory in timeout()!");
     newp->c_arg = arg;
     newp->c_func = func;
-    gettimeofday(&timenow, NULL);
+    get_time(&timenow);
     newp->c_time.tv_sec = timenow.tv_sec + secs;
     newp->c_time.tv_usec = timenow.tv_usec + usecs;
     if (newp->c_time.tv_usec >= 1000000) {
@@ -1331,7 +1331,7 @@ calltimeout()
     while (callout != NULL) {
        p = callout;
 
-       if (gettimeofday(&timenow, NULL) < 0)
+       if (get_time(&timenow) < 0)
            fatal("Failed to get time of day: %m");
        if (!(p->c_time.tv_sec < timenow.tv_sec
              || (p->c_time.tv_sec == timenow.tv_sec
@@ -1356,7 +1356,7 @@ timeleft(tvp)
     if (callout == NULL)
        return NULL;
 
-    gettimeofday(&timenow, NULL);
+    get_time(&timenow);
     tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
     tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
     if (tvp->tv_usec < 0) {

diff --git a/pppd/plugins/radius/buildreq.c b/pppd/plugins/radius/buildreq.c
index 955b05234b8e408513a3d04eb4d04a28da900475..3edd5ea92e1c0e0a864975670f5fa57b8aa87aa0 100644 (file)
--- a/pppd/plugins/radius/buildreq.c
+++ b/pppd/plugins/radius/buildreq.c
@@ -293,7 +293,7 @@ int rc_acct_using_server(SERVER *acctserver,
        SEND_DATA       data;
        VALUE_PAIR      *adt_vp;
        int             result;
-       time_t          start_time, dtime;
+       struct timeval  start_time, dtime;
        char            msg[4096];
        int             i;
        int             timeout = rc_conf_int("radius_timeout");
@@ -320,11 +320,11 @@ int rc_acct_using_server(SERVER *acctserver,
         * Fill in Acct-Delay-Time
         */
 
-       dtime = 0;
-       if ((adt_vp = rc_avpair_add(&(data.send_pairs), PW_ACCT_DELAY_TIME, &dtime, 0, VENDOR_NONE)) == NULL)
+       dtime.tv_sec = 0;
+       if ((adt_vp = rc_avpair_add(&(data.send_pairs), PW_ACCT_DELAY_TIME, &dtime.tv_sec, 0, VENDOR_NONE)) == NULL)
                return (ERROR_RC);
 
-       start_time = time(NULL);
+       get_time(&start_time);
        result = ERROR_RC;
        for(i=0; (i<acctserver->max) && (result != OK_RC) && (result != BADRESP_RC)
                ; i++)
@@ -336,8 +336,9 @@ int rc_acct_using_server(SERVER *acctserver,
                rc_buildreq(&data, PW_ACCOUNTING_REQUEST, acctserver->name[i],
                            acctserver->port[i], timeout, retries);
 
-               dtime = time(NULL) - start_time;
-               rc_avpair_assign(adt_vp, &dtime, 0);
+               get_time(&dtime);
+               dtime.tv_sec -= start_time.tv_sec;
+               rc_avpair_assign(adt_vp, &dtime.tv_sec, 0);
 
                result = rc_send_server (&data, msg, NULL);
        }

diff --git a/pppd/plugins/rp-pppoe/discovery.c b/pppd/plugins/rp-pppoe/discovery.c
index 2aebcd1c13ac1205511e32bade4d9d22442668b7..a4e4cec93ce1c21ebd8841813b6ee33cdc67d13f 100644 (file)
--- a/pppd/plugins/rp-pppoe/discovery.c
+++ b/pppd/plugins/rp-pppoe/discovery.c
@@ -45,8 +45,8 @@ static int time_left(struct timeval *diff, struct timeval *exp)
 {
     struct timeval now;
 
-    if (gettimeofday(&now, NULL) < 0) {
-       error("gettimeofday: %m");
+    if (get_time(&now) < 0) {
+       error("get_time: %m");
        return 0;
     }
 
@@ -353,8 +353,8 @@ waitForPADO(PPPoEConnection *conn, int timeout)
     conn->seenMaxPayload = 0;
     conn->error = 0;
 
-    if (gettimeofday(&expire_at, NULL) < 0) {
-       error("gettimeofday (waitForPADO): %m");
+    if (get_time(&expire_at) < 0) {
+       error("get_time (waitForPADO): %m");
        return;
     }
     expire_at.tv_sec += timeout;
@@ -533,8 +533,8 @@ waitForPADS(PPPoEConnection *conn, int timeout)
     PPPoEPacket packet;
     int len;
 
-    if (gettimeofday(&expire_at, NULL) < 0) {
-       error("gettimeofday (waitForPADS): %m");
+    if (get_time(&expire_at) < 0) {
+       error("get_time (waitForPADS): %m");
        return;
     }
     expire_at.tv_sec += timeout;

diff --git a/pppd/pppd.h b/pppd/pppd.h
index 6e3743fd9c97de74caf9638e717aa60525bebabb..9214aaeb6ff1c778032c922af3cc62bc6de10b5b 100644 (file)
--- a/pppd/pppd.h
+++ b/pppd/pppd.h
@@ -705,6 +705,8 @@ int  cipxfaddr __P((int));
 #endif
 int  get_if_hwaddr __P((u_char *addr, char *name));
 char *get_first_ethernet __P((void));
+int get_time __P((struct timeval *));
+                               /* Get current time, monotonic if possible. */
 
 /* Procedures exported from options.c */
 int setipaddr __P((char *, char **, int)); /* Set local/remote ip addresses */

diff --git a/pppd/sys-linux.c b/pppd/sys-linux.c
index 761aafc88f92530b27264d4bfa87215b66ff194c..b3959915938c19b758c38b0d267e0d2a95abce6a 100644 (file)
--- a/pppd/sys-linux.c
+++ b/pppd/sys-linux.c
@@ -2966,3 +2966,38 @@ ether_to_eui64(eui64_t *p_eui64)
     return 1;
 }
 #endif
+
+/********************************************************************
+ *
+ * get_time - Get current time, monotonic if possible.
+ */
+int
+get_time(struct timeval *tv)
+{
+/* Old glibc (< 2.3.4) does define CLOCK_MONOTONIC, but kernel may have it.
+ * Runtime checking makes it safe. */
+#ifndef CLOCK_MONOTONIC
+#define CLOCK_MONOTONIC 1
+#endif
+    static int monotonic = -1;
+    struct timespec ts;
+    int ret;
+
+    if (monotonic) {
+       ret = clock_gettime(CLOCK_MONOTONIC, &ts);
+       if (ret == 0) {
+           monotonic = 1;
+           if (tv) {
+               tv->tv_sec = ts.tv_sec;
+               tv->tv_usec = ts.tv_nsec / 1000;
+           }
+           return ret;
+       } else if (monotonic > 0)
+           return ret;
+
+       monotonic = 0;
+       warn("Couldn't use monotonic clock source: %m");
+    }
+
+    return gettimeofday(tv, NULL);
+}

diff --git a/pppd/sys-solaris.c b/pppd/sys-solaris.c
index 93d90332e0d4f2116b17800970e082cf193640dd..83b1815080cd60be33e0e02aa283ed6bbb73b4be 100644 (file)
--- a/pppd/sys-solaris.c
+++ b/pppd/sys-solaris.c
@@ -114,6 +114,7 @@
 #include <sys/dlpi.h>
 #include <sys/stat.h>
 #include <sys/mkdev.h>
+#include <sys/time.h>
 #include <net/if.h>
 #include <net/if_arp.h>
 #include <net/route.h>
@@ -2783,3 +2784,13 @@ get_pty(master_fdp, slave_fdp, slave_name, uid)
 
     return 1;
 }
+
+/********************************************************************
+ *
+ * get_time - Get current time, monotonic if possible.
+ */
+int
+get_time(struct timeval *tv)
+{
+    return gettimeofday(tv, NULL);
+}

diff --git a/pppd/tty.c b/pppd/tty.c
index c9a0b33715bc829a7dae446f5f5e1b29d1d78e26..485a44d8102cf665b878c384279896217789eb5f 100644 (file)
--- a/pppd/tty.c
+++ b/pppd/tty.c
@@ -1072,7 +1072,7 @@ charshunt(ifd, ofd, record_file)
     pty_readable = stdin_readable = 1;
 
     ilevel = olevel = 0;
-    gettimeofday(&levelt, NULL);
+    get_time(&levelt);
     if (max_data_rate) {
        max_level = max_data_rate / 10;
        if (max_level < 100)
@@ -1121,7 +1121,7 @@ charshunt(ifd, ofd, record_file)
            int nbt;
            struct timeval now;
 
-           gettimeofday(&now, NULL);
+           get_time(&now);
            dt = (now.tv_sec - levelt.tv_sec
                  + (now.tv_usec - levelt.tv_usec) / 1e6);
            nbt = (int)(dt * max_data_rate);