This is equivalent to lookup_ip() except that it accepts DNS names also.
---
lib/socket-util.c | 31 +++++++++++++++++++++++++++++++
lib/socket-util.h | 4 ++++
2 files changed, 35 insertions(+), 0 deletions(-)
diff --git a/lib/socket-util.c b/lib/socket-util.c
index 07687ba..c436724 100644
--- a/lib/socket-util.c
+++ b/lib/socket-util.c
@@ -145,6 +145,37 @@ lookup_ipv6(const char *host_name, struct in6_addr *addr)
return 0;
}
+/* Translates 'host_name', which must be a host name or a string representation
+ * of an IP address, into a numeric IP address in '*addr'. Returns 0 if
+ * successful, otherwise a positive errno value.
+ *
+ * Most Open vSwitch code should not use this because it causes deadlocks:
+ * gethostbyname() sends out a DNS request but that starts a new flow for which
+ * OVS must set up a flow, but it can't because it's waiting for a DNS reply.
+ * The synchronous lookup also delays other activty. (Of course we can solve
+ * this but it doesn't seem worthwhile quite yet.) */
+int
+lookup_hostname(const char *host_name, struct in_addr *addr)
+{
+ struct hostent *h;
+
+ if (inet_aton(host_name, addr)) {
+ return 0;
+ }
+
+ h = gethostbyname(host_name);
+ if (h) {
+ *addr = *(struct in_addr *) h->h_addr;
+ return 0;
+ }
+
+ return (h_errno == HOST_NOT_FOUND ? ENOENT
+ : h_errno == TRY_AGAIN ? EAGAIN
+ : h_errno == NO_RECOVERY ? EIO
+ : h_errno == NO_ADDRESS ? ENXIO
+ : EINVAL);
+}
+
/* Returns the error condition associated with socket 'fd' and resets the
* socket's error status. */
int
diff --git a/lib/socket-util.h b/lib/socket-util.h
index 10f821e..ce7cd5b 100644
--- a/lib/socket-util.h
+++ b/lib/socket-util.h
@@ -24,8 +24,12 @@
int set_nonblocking(int fd);
int get_max_fds(void);
+
int lookup_ip(const char *host_name, struct in_addr *address);
int lookup_ipv6(const char *host_name, struct in6_addr *address);
+
+int lookup_hostname(const char *host_name, struct in_addr *);
+
int get_socket_error(int sock);
int check_connection_completion(int fd);
int drain_rcvbuf(int fd);
--
1.7.4.4
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