+/**
+ * nfs_name_to_address - resolve hostname to an IPv4 or IPv6 socket address
+ * @hostname: pointer to C string containing DNS hostname to resolve
+ * @sap: pointer to buffer to fill with socket address
+ * @len: IN: size of buffer to fill; OUT: size of socket address
+ *
+ * Returns 1 and places a socket address at @sap if successful;
+ * otherwise zero.
+ */
+int nfs_name_to_address(const char *hostname,
+ const sa_family_t af_hint,
+ struct sockaddr *sap, socklen_t *salen)
+{
+ struct addrinfo *gai_results;
+ struct addrinfo gai_hint = {
+ .ai_family = af_hint,
+ .ai_flags = AI_ADDRCONFIG,
+ };
+ socklen_t len = *salen;
+ int error, ret = 0;
+
+ if (af_hint == AF_INET6)
+ gai_hint.ai_flags |= AI_V4MAPPED|AI_ALL;
+
+ *salen = 0;
+
+ error = getaddrinfo(hostname, NULL, &gai_hint, &gai_results);
+ if (error) {
+ nfs_error(_("%s: DNS resolution failed for %s: %s"),
+ progname, hostname, (error == EAI_SYSTEM ?
+ strerror(errno) : gai_strerror(error)));
+ return ret;
+ }
+
+ switch (gai_results->ai_addr->sa_family) {
+ case AF_INET:
+ case AF_INET6:
+ if (len >= gai_results->ai_addrlen) {
+ *salen = gai_results->ai_addrlen;
+ memcpy(sap, gai_results->ai_addr, *salen);
+ ret = 1;
+ }
+ break;
+ default:
+ /* things are really broken if we get here, so warn */
+ nfs_error(_("%s: unrecognized DNS resolution results for %s"),
+ progname, hostname);
+ break;
+ }
+
+ freeaddrinfo(gai_results);
+ return ret;
+}
+
+/**
+ * nfs_gethostbyname - resolve a hostname to an IPv4 address
+ * @hostname: pointer to a C string containing a DNS hostname
+ * @saddr: returns an IPv4 address
+ *
+ * Returns 1 if successful, otherwise zero.
+ */
+int nfs_gethostbyname(const char *hostname, struct sockaddr_in *sin)
+{
+ socklen_t len = sizeof(*sin);
+
+ return nfs_name_to_address(hostname, AF_INET,
+ (struct sockaddr *)sin, &len);
+}
+
+/**
+ * nfs_string_to_sockaddr - convert string address to sockaddr
+ * @address: pointer to presentation format address to convert
+ * @addrlen: length of presentation address
+ * @sap: pointer to socket address buffer to fill in
+ * @salen: IN: length of address buffer
+ * OUT: length of converted socket address
+ *
+ * Convert a presentation format address string to a socket address.
+ * Similar to nfs_name_to_address(), but the DNS query is squelched,
+ * and won't make any noise if the getaddrinfo() call fails.
+ *
+ * Returns 1 and fills in @sap and @salen if successful; otherwise zero.
+ *
+ * See RFC 4038 section 5.1 or RFC 3513 section 2.2 for more details
+ * on presenting IPv6 addresses as text strings.
+ */
+int nfs_string_to_sockaddr(const char *address, const size_t addrlen,
+ struct sockaddr *sap, socklen_t *salen)
+{
+ struct addrinfo *gai_results;
+ struct addrinfo gai_hint = {
+ .ai_flags = AI_NUMERICHOST,
+ };
+ socklen_t len = *salen;
+ int ret = 0;
+
+ *salen = 0;
+
+ if (getaddrinfo(address, NULL, &gai_hint, &gai_results) == 0) {
+ switch (gai_results->ai_addr->sa_family) {
+ case AF_INET:
+ case AF_INET6:
+ if (len >= gai_results->ai_addrlen) {
+ *salen = gai_results->ai_addrlen;
+ memcpy(sap, gai_results->ai_addr, *salen);
+ ret = 1;