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-rw-r--r--resolv/res_send.c58
1 files changed, 47 insertions, 11 deletions
diff --git a/resolv/res_send.c b/resolv/res_send.c
index ac5cc0b..ce4c11f 100644
--- a/resolv/res_send.c
+++ b/resolv/res_send.c
@@ -95,6 +95,7 @@ static const char rcsid[] = "$BINDId: res_send.c,v 8.38 2000/03/30 20:16:51 vixi
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#include <kernel-features.h>
#if PACKETSZ > 65536
#define MAXPACKET PACKETSZ
@@ -103,6 +104,13 @@ static const char rcsid[] = "$BINDId: res_send.c,v 8.38 2000/03/30 20:16:51 vixi
#endif
+#ifndef __ASSUME_O_CLOEXEC
+static int __have_o_nonblock;
+#else
+# define __have_o_nonblock 0
+#endif
+
+
/* From ev_streams.c. */
static inline void
@@ -920,8 +928,20 @@ send_dg(res_state statp,
if (EXT(statp).nssocks[ns] == -1) {
/* only try IPv6 if IPv6 NS and if not failed before */
if ((EXT(statp).nscount6 > 0) && !statp->ipv6_unavail) {
- EXT(statp).nssocks[ns] =
- socket(PF_INET6, SOCK_DGRAM, 0);
+ if (__have_o_nonblock >= 0) {
+ EXT(statp).nssocks[ns] =
+ socket(PF_INET6, SOCK_DGRAM|SOCK_NONBLOCK,
+ 0);
+#ifndef __ASSUME_O_CLOEXEC
+ if (__have_o_nonblock == 0)
+ __have_o_nonblock
+ = (EXT(statp).nssocks[ns] == -1
+ && errno == EINVAL ? -1 : 1);
+#endif
+ }
+ if (__have_o_nonblock < 0)
+ EXT(statp).nssocks[ns] =
+ socket(PF_INET6, SOCK_DGRAM, 0);
if (EXT(statp).nssocks[ns] < 0)
statp->ipv6_unavail = errno == EAFNOSUPPORT;
/* If IPv6 socket and nsap is IPv4, make it
@@ -929,8 +949,22 @@ send_dg(res_state statp,
else if (nsap->sin6_family == AF_INET)
convaddr4to6(nsap);
}
- if (EXT(statp).nssocks[ns] < 0)
- EXT(statp).nssocks[ns] = socket(PF_INET, SOCK_DGRAM, 0);
+ if (EXT(statp).nssocks[ns] < 0) {
+ if (__have_o_nonblock >= 0) {
+ EXT(statp).nssocks[ns]
+ = socket(PF_INET, SOCK_DGRAM|SOCK_NONBLOCK,
+ 0);
+#ifndef __ASSUME_O_CLOEXEC
+ if (__have_o_nonblock == 0)
+ __have_o_nonblock
+ = (EXT(statp).nssocks[ns] == -1
+ && errno == EINVAL ? -1 : 1);
+#endif
+ }
+ if (__have_o_nonblock < 0)
+ EXT(statp).nssocks[ns]
+ = socket(PF_INET, SOCK_DGRAM, 0);
+ }
if (EXT(statp).nssocks[ns] < 0) {
*terrno = errno;
Perror(statp, stderr, "socket(dg)", errno);
@@ -955,13 +989,15 @@ send_dg(res_state statp,
__res_iclose(statp, false);
return (0);
}
- /* Make socket non-blocking. */
- int fl = __fcntl (EXT(statp).nssocks[ns], F_GETFL);
- if (fl != -1)
- __fcntl (EXT(statp).nssocks[ns], F_SETFL,
- fl | O_NONBLOCK);
- Dprint(statp->options & RES_DEBUG,
- (stdout, ";; new DG socket\n"))
+ if (__have_o_nonblock < 0) {
+ /* Make socket non-blocking. */
+ int fl = __fcntl (EXT(statp).nssocks[ns], F_GETFL);
+ if (fl != -1)
+ __fcntl (EXT(statp).nssocks[ns], F_SETFL,
+ fl | O_NONBLOCK);
+ Dprint(statp->options & RES_DEBUG,
+ (stdout, ";; new DG socket\n"))
+ }
}
/*