Hi,
I've attached an updated patch that does things a little more
efficiently. I didn't spot this easier solution at first.
Thanks,
Steven.
Treat DNS lookup caches as invalid when the IP address being looked up
changes.
--- a/ping.c
+++ b/ping.c
@@ -1244,10 +1244,13 @@
{
struct hostent *hp;
static char buf[4096] = "";
+ static __u32 last_addr = 0;
- if (*buf)
+ if (*buf && addr == last_addr)
return(buf);
+ last_addr = addr;
+
in_pr_addr = !setjmp(pr_addr_jmp);
if (exiting || (options & F_NUMERIC) ||
--- a/ping6.c
+++ b/ping6.c
@@ -1796,6 +1796,7 @@
{
static struct hostent *hp = NULL;
static char *s;
+ static struct in6_addr last_addr;
#ifdef USE_IDN
free(s);
@@ -1803,8 +1804,11 @@
in_pr_addr = !setjmp(pr_addr_jmp);
- if (!hp && !(exiting || options&F_NUMERIC))
+ if (!(hp && memcmp(addr, &last_addr, sizeof(struct in6_addr))) &&
+ !(exiting || options&F_NUMERIC)) {
hp = gethostbyaddr((__u8*)addr, sizeof(struct in6_addr), AF_INET6);
+ memcpy(&last_addr, addr, sizeof(struct in6_addr));
+ }
in_pr_addr = 0;
