[libvirt PATCH v2 2/2] nwfilter: Fix timeout data type reported by coverity

[Erik Skultety]

Coverity reports:
    virNWFilterSnoopIPLeaseUpdate(virNWFilterSnoopIPLease *ipl,
                                  time_t timeout)
    {
        if (timeout < ipl->timeout)
            return;  /* no take-backs */

        virNWFilterSnoopIPLeaseTimerDel(ipl);
 >>> CID 396747:  High impact quality  (Y2K38_SAFETY)
 >>> A "time_t" value is stored in an integer with too few bits
     to accommodate it. The expression "timeout" is cast to
     "unsigned int".
        ipl->timeout = timeout;
        virNWFilterSnoopIPLeaseTimerAdd(ipl);
    }

Given that it doesn't make sense for a timeout to be negative, let's
store it as unsigned long long and typecast all affected time_t
occurrences accordingly. Since the affected places only ever get the
current time which is not going to be negative (unless it's year 2038
and a 32bit architecture) we can safely cast them.

Signed-off-by: Erik Skultety <eskultet at redhat.com>
---
 src/nwfilter/nwfilter_dhcpsnoop.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/nwfilter/nwfilter_dhcpsnoop.c b/src/nwfilter/nwfilter_dhcpsnoop.c
index 18812c0b20..0977951be1 100644
--- a/src/nwfilter/nwfilter_dhcpsnoop.c
+++ b/src/nwfilter/nwfilter_dhcpsnoop.c
@@ -146,7 +146,7 @@ struct _virNWFilterSnoopIPLease {
     virSocketAddr              ipAddress;
     virSocketAddr              ipServer;
     virNWFilterSnoopReq *    snoopReq;
-    unsigned int               timeout;
+    unsigned long long timeout;
     /* timer list */
     virNWFilterSnoopIPLease *prev;
     virNWFilterSnoopIPLease *next;
@@ -415,7 +415,8 @@ virNWFilterSnoopIPLeaseInstallRule(virNWFilterSnoopIPLease *ipl,
  * virNWFilterSnoopIPLeaseUpdate - update the timeout on an IP lease
  */
 static void
-virNWFilterSnoopIPLeaseUpdate(virNWFilterSnoopIPLease *ipl, time_t timeout)
+virNWFilterSnoopIPLeaseUpdate(virNWFilterSnoopIPLease *ipl,
+                              unsigned long long timeout)
 {
     if (timeout < ipl->timeout)
         return;  /* no take-backs */
@@ -447,7 +448,7 @@ virNWFilterSnoopIPLeaseGetByIP(virNWFilterSnoopIPLease *start,
 static unsigned int
 virNWFilterSnoopReqLeaseTimerRun(virNWFilterSnoopReq *req)
 {
-    time_t now = time(0);
+    unsigned long long now = time(0);
     bool is_last = false;
 
     /* protect req->start */
@@ -1580,7 +1581,8 @@ virNWFilterSnoopLeaseFileWrite(int lfd, const char *ifkey,
         return -1;
 
     /* time intf ip dhcpserver */
-    lbuf = g_strdup_printf("%u %s %s %s\n", ipl->timeout, ifkey, ipstr, dhcpstr);
+    lbuf = g_strdup_printf("%llu %s %s %s\n",
+                           ipl->timeout, ifkey, ipstr, dhcpstr);
     len = strlen(lbuf);
 
     if (safewrite(lfd, lbuf, len) != len) {
@@ -1737,7 +1739,7 @@ virNWFilterSnoopLeaseFileLoad(void)
         }
         ln++;
         /* key len 54 = "VMUUID"+'-'+"MAC" */
-        if (sscanf(line, "%u %54s %15s %15s", &ipl.timeout,
+        if (sscanf(line, "%llu %54s %15s %15s", &ipl.timeout,
                    ifkey, ipstr, srvstr) < 4) {
             virReportError(VIR_ERR_INTERNAL_ERROR,
                            _("virNWFilterSnoopLeaseFileLoad lease file "
-- 
2.37.2