From 036f99c8019da762fa33ca81b9b5c8b5a480d1ac Mon Sep 17 00:00:00 2001
From: hniksic <devnull@localhost>
Date: Sun, 14 Apr 2002 19:21:38 -0700
Subject: [PATCH] [svn] Extend the timeout to DNS lookups. Published in
<sxsn0w57ldh.fsf@florida.arsdigita.de>.
---
src/ChangeLog | 6 ++++
src/host.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 96 insertions(+), 7 deletions(-)
diff --git a/src/ChangeLog b/src/ChangeLog
index f54dd7f4..e1f725b8 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2002-04-15 Hrvoje Niksic <hniksic@arsdigita.com>
+
+ * host.c (getaddrinfo_with_timeout): New function.
+ (gethostbyname_with_timeout): Ditto.
+ (lookup_host): Use them.
+
2002-04-14 Hrvoje Niksic <hniksic@arsdigita.com>
* utils.c (number_to_string): Handle the case when n < -INT_MAX.
diff --git a/src/host.c b/src/host.c
index 45455bf0..62485c6e 100644
--- a/src/host.c
+++ b/src/host.c
@@ -459,6 +459,85 @@ map_ip_to_ipv4 (ip_address *ip, ip4_address *ipv4)
return 1;
}
+/* Versions of gethostbyname and getaddrinfo that support timeout. */
+
+#ifndef INET6
+
+struct ghbnwt_context {
+ const char *host_name;
+ struct hostent *hptr;
+};
+
+static void
+gethostbyname_with_timeout_callback (void *arg)
+{
+ struct ghbnwt_context *ctx = (struct ghbnwt_context *)arg;
+ ctx->hptr = gethostbyname (ctx->host_name);
+}
+
+/* Just like gethostbyname, except it times out after TIMEOUT seconds.
+ In case of timeout, NULL is returned and errno is set to ETIMEDOUT.
+ The function makes sure that when NULL is returned for reasons
+ other than timeout, errno is reset. */
+
+static struct hostent *
+gethostbyname_with_timeout (const char *host_name, int timeout)
+{
+ struct ghbnwt_context ctx;
+ ctx.host_name = host_name;
+ if (run_with_timeout (timeout, gethostbyname_with_timeout_callback, &ctx))
+ {
+ h_errno = HOST_NOT_FOUND;
+ errno = ETIMEDOUT;
+ return NULL;
+ }
+ if (!ctx.hptr)
+ errno = 0;
+ return ctx.hptr;
+}
+
+#else /* INET6 */
+
+struct gaiwt_context {
+ const char *node;
+ const char *service;
+ const struct addrinfo *hints;
+ struct addrinfo **res;
+ int exit_code;
+};
+
+static void
+getaddrinfo_with_timeout_callback (void *arg)
+{
+ struct gaiwt_context *ctx = (struct gaiwt_context *)arg;
+ ctx->exit_code = getaddrinfo (ctx->node, ctx->service, ctx->hints, ctx->res);
+}
+
+/* Just like getaddrinfo, except it times out after TIMEOUT seconds.
+ In case of timeout, the EAI_SYSTEM error code is returned and errno
+ is set to ETIMEDOUT. */
+
+static int
+getaddrinfo_with_timeout (const char *node, const char *service,
+ const struct addrinfo *hints, struct addrinfo **res,
+ int timeout)
+{
+ struct gaiwt_context ctx;
+ ctx.node = node;
+ ctx.service = service;
+ ctx.hints = hints;
+ ctx.res = res;
+
+ if (run_with_timeout (timeout, getaddrinfo_with_timeout_callback, &ctx))
+ {
+ errno = ETIMEDOUT;
+ return EAI_SYSTEM;
+ }
+ return ctx.exit_code;
+}
+
+#endif /* INET6 */
+
/* Pretty-print ADDR. When compiled without IPv6, this is the same as
inet_ntoa. With IPv6, it either prints an IPv6 address or an IPv4
address. */
@@ -551,9 +630,7 @@ lookup_host (const char *host, int silent)
if (!silent)
logprintf (LOG_VERBOSE, _("Resolving %s... "), host);
- /* Host name lookup goes on below. #### We should implement
- getaddrinfo_with_timeout and gethostbyname_with_timeout the same
- way connect.c implements connect_with_timeout. */
+ /* Host name lookup goes on below. */
#ifdef INET6
{
@@ -566,12 +643,13 @@ lookup_host (const char *host, int silent)
else
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
- err = getaddrinfo (host, NULL, &hints, &ai);
+ err = getaddrinfo_with_timeout (host, NULL, &hints, &ai, opt.timeout);
if (err != 0 || ai == NULL)
{
if (!silent)
- logprintf (LOG_VERBOSE, _("failed: %s.\n"), gai_strerror (err));
+ logprintf (LOG_VERBOSE, _("failed: %s.\n"),
+ err != EAI_SYSTEM ? gai_strerror (err) : strerror (errno));
return NULL;
}
al = address_list_from_addrinfo (ai);
@@ -579,11 +657,16 @@ lookup_host (const char *host, int silent)
}
#else
{
- struct hostent *hptr = gethostbyname (host);
+ struct hostent *hptr = gethostbyname_with_timeout (host, opt.timeout);
if (!hptr)
{
if (!silent)
- logprintf (LOG_VERBOSE, _("failed: %s.\n"), herrmsg (h_errno));
+ {
+ if (errno != ETIMEDOUT)
+ logprintf (LOG_VERBOSE, _("failed: %s.\n"), herrmsg (h_errno));
+ else
+ logputs (LOG_VERBOSE, _("failed: timed out.\n"));
+ }
return NULL;
}
/* Do all systems have h_addr_list, or is it a newer thing? If