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stubs: don't call DNS_Name2IPAddress handler directly

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Instead of calling the handler directly schedule a timeout with zero
delay for resolving to make the function behave similarly to the real
asynchronous resolver. This should prevent problems with code that
inadvertently depends on this behavior and which would break only when
compiled without support for asynchronous resolving.
This commit is contained in:
Miroslav Lichvar 2015-09-29 17:39:27 +02:00
parent 60721d2cc1
commit 967e358dbc
2 changed files with 31 additions and 7 deletions
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3
nameserv_async.h
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@ -34,8 +34,7 @@
typedef void (*DNS_NameResolveHandler)(DNS_Status status, int n_addrs, IPAddr *ip_addrs, void *anything);
/* Request resolving of a name to IP address. The handler will be
called when the result is available, but it may be also called
directly from this function call. */
called when the result is available. */
extern void DNS_Name2IPAddressAsync(const char *name, DNS_NameResolveHandler handler, void *anything);
#endif

35
stubs.c
View file

@ -32,12 +32,14 @@
#include "keys.h"
#include "logging.h"
#include "manual.h"
#include "memory.h"
#include "nameserv.h"
#include "nameserv_async.h"
#include "ntp_core.h"
#include "ntp_io.h"
#include "ntp_sources.h"
#include "refclock.h"
#include "sched.h"
#ifndef FEAT_ASYNCDNS
@ -45,20 +47,43 @@
/* This is a blocking implementation used when asynchronous resolving is not available */
void
DNS_Name2IPAddressAsync(const char *name, DNS_NameResolveHandler handler, void *anything)
struct DNS_Async_Instance {
const char *name;
DNS_NameResolveHandler handler;
void *arg;
};
static void
resolve_name(void *anything)
{
struct DNS_Async_Instance *inst;
IPAddr addrs[MAX_ADDRESSES];
DNS_Status status;
int i;
status = DNS_Name2IPAddress(name, addrs, MAX_ADDRESSES);
inst = (struct DNS_Async_Instance *)anything;
status = DNS_Name2IPAddress(inst->name, addrs, MAX_ADDRESSES);
for (i = 0; status == DNS_Success && i < MAX_ADDRESSES &&
addrs[i].family != IPADDR_UNSPEC; i++)
addrs[i].family != IPADDR_UNSPEC; i++)
;
(handler)(status, i, addrs, anything);
(inst->handler)(status, i, addrs, inst->arg);
Free(inst);
}
void
DNS_Name2IPAddressAsync(const char *name, DNS_NameResolveHandler handler, void *anything)
{
struct DNS_Async_Instance *inst;
inst = MallocNew(struct DNS_Async_Instance);
inst->name = name;
inst->handler = handler;
inst->arg = anything;
SCH_AddTimeoutByDelay(0.0, resolve_name, inst);
}
#endif /* !FEAT_ASYNCDNS */