Retry name resolving after temporary failure few times before giving up

This is a temporary fix to allow starting when resolv.conf is not ready yet
(e.g. when using NetworkManager). It may delay start up to 1022 seconds.
This commit is contained in:
Miroslav Lichvar 2008-11-10 14:42:41 +01:00
parent fd2641bcb9
commit 0148ecaea0
4 changed files with 32 additions and 5 deletions

View file

@ -61,7 +61,7 @@ CPS_ParseNTPSourceAdd(const char *line, CPS_NTP_Source *src)
ok = 0;
if (sscanf(line, "%" SMAXLEN "s%n", hostname, &n) == 1) {
src->ip_addr = DNS_Name2IPAddress(hostname);
src->ip_addr = DNS_Name2IPAddressRetry(hostname);
if (src->ip_addr != DNS_Failed_Address) {
ok = 1;
}

4
conf.c
View file

@ -584,7 +584,7 @@ parse_initstepslew(const char *line)
}
while (*p) {
if (sscanf(p, "%" SHOSTNAME_LEN "s%n", hostname, &n) == 1) {
ip_addr = DNS_Name2IPAddress(hostname);
ip_addr = DNS_Name2IPAddressRetry(hostname);
if (ip_addr != DNS_Failed_Address) {
init_srcs_ip[n_init_srcs] = ip_addr;
++n_init_srcs;
@ -746,7 +746,7 @@ parse_allow_deny(const char *line, AllowDeny *list, int allow)
}
} else {
ip_addr = DNS_Name2IPAddress(p);
ip_addr = DNS_Name2IPAddressRetry(p);
if (ip_addr != DNS_Failed_Address) {
new_node = MallocNew(AllowDeny);
new_node->allow = allow;

View file

@ -32,18 +32,28 @@
#include "sysincl.h"
#include "nameserv.h"
#include <resolv.h>
/* ================================================== */
unsigned long
DNS_Name2IPAddress(const char *name)
static unsigned int retries = 0;
static unsigned long
Name2IPAddress(const char *name, int retry)
{
struct hostent *host;
unsigned char *address0;
unsigned long result;
try_again:
host = gethostbyname(name);
if (host == NULL) {
if (retry && h_errno == TRY_AGAIN && retries < 10) {
sleep(2 << retries);
retries++;
res_init();
goto try_again;
}
result = DNS_Failed_Address;
} else {
address0 = host->h_addr_list[0];
@ -54,7 +64,22 @@ DNS_Name2IPAddress(const char *name)
}
return result;
}
/* ================================================== */
unsigned long
DNS_Name2IPAddress(const char *name)
{
return Name2IPAddress(name, 0);
}
/* ================================================== */
unsigned long
DNS_Name2IPAddressRetry(const char *name)
{
return Name2IPAddress(name, 1);
}
/* ================================================== */

View file

@ -36,6 +36,8 @@ static const unsigned long DNS_Failed_Address = 0x0UL;
extern unsigned long DNS_Name2IPAddress(const char *name);
extern unsigned long DNS_Name2IPAddressRetry(const char *name);
const char *DNS_IPAddress2Name(unsigned long ip_addr);
#endif /* GOT_NAMESERV_H */