X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fsocket-util.c;h=3fcd5a1e8e79f73210c0d2ec70feeb33b370a1dd;hb=1a487cec005de9f77cb9d1a2492681af293f73fb;hp=e5b86e42773a4105c9cac09a1b5b99523ff5124c;hpb=e3fdfed11b8c56aa6a8deffe11a552fed7e7adbc;p=openvswitch

diff --git a/lib/socket-util.c b/lib/socket-util.c
index e5b86e42..3fcd5a1e 100644
--- a/lib/socket-util.c
+++ b/lib/socket-util.c
@@ -73,25 +73,16 @@ get_max_fds(void)
     return max_fds;
 }
 
-/* Translates 'host_name', which may be a DNS name or an IP address, into a
- * numeric IP address in '*addr'.  Returns 0 if successful, otherwise a
- * positive errno value. */
+/* Translates 'host_name', which must be a string representation of an IP
+ * address, into a numeric IP address in '*addr'.  Returns 0 if successful,
+ * otherwise a positive errno value. */
 int
 lookup_ip(const char *host_name, struct in_addr *addr) 
 {
     if (!inet_aton(host_name, addr)) {
-        struct hostent *he = gethostbyname(host_name);
-        if (he == NULL) {
-            struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
-            VLOG_ERR_RL(&rl, "gethostbyname(%s): %s", host_name,
-                        (h_errno == HOST_NOT_FOUND ? "host not found"
-                         : h_errno == TRY_AGAIN ? "try again"
-                         : h_errno == NO_RECOVERY ? "non-recoverable error"
-                         : h_errno == NO_ADDRESS ? "no address"
-                         : "unknown error"));
-            return ENOENT;
-        }
-        addr->s_addr = *(uint32_t *) he->h_addr;
+        struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
+        VLOG_ERR_RL(&rl, "\"%s\" is not a valid IP address", host_name);
+        return ENOENT;
     }
     return 0;
 }
@@ -466,6 +457,24 @@ exit:
     return error ? -error : fd;
 }
 
+/* Returns a readable and writable fd for /dev/null, if successful, otherwise
+ * a negative errno value.  The caller must not close the returned fd (because
+ * the same fd will be handed out to subsequent callers). */
+int
+get_null_fd(void)
+{
+    static int null_fd = -1;
+    if (null_fd < 0) {
+        null_fd = open("/dev/null", O_RDWR);
+        if (null_fd < 0) {
+            int error = errno;
+            VLOG_ERR("could not open /dev/null: %s", strerror(error));
+            return -error;
+        }
+    }
+    return null_fd;
+}
+
 int
 read_fully(int fd, void *p_, size_t size, size_t *bytes_read)
 {