Introduce a new DNS resolver function in utils/mount/network.c that uses

[nfs-utils.git] / utils / mount / network.c

diff --git a/utils/mount/network.c b/utils/mount/network.c
index ab7f6d01072b73ae918fcada746bf50583f69f28..30a4d40ef78c7216e149e6cd58a0dc7685d05bfb 100644 (file)
--- a/utils/mount/network.c
+++ b/utils/mount/network.c
@@ -143,6 +143,60 @@ static const unsigned long probe_mnt3_first[] = {
        0,
 };
 
+/**
+ * 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
@@ -150,26 +204,12 @@ static const unsigned long probe_mnt3_first[] = {
  *
  * Returns 1 if successful, otherwise zero.
  */
-int nfs_gethostbyname(const char *hostname, struct sockaddr_in *saddr)
+int nfs_gethostbyname(const char *hostname, struct sockaddr_in *sin)
 {
-       struct hostent *hp;
-
-       saddr->sin_family = AF_INET;
-       if (!inet_aton(hostname, &saddr->sin_addr)) {
-               if ((hp = gethostbyname(hostname)) == NULL) {
-                       nfs_error(_("%s: can't get address for %s\n"),
-                                       progname, hostname);
-                       return 0;
-               } else {
-                       if (hp->h_length > sizeof(*saddr)) {
-                               nfs_error(_("%s: got bad hp->h_length\n"),
-                                               progname);
-                               hp->h_length = sizeof(*saddr);
-                       }
-                       memcpy(&saddr->sin_addr, hp->h_addr, hp->h_length);
-               }
-       }
-       return 1;
+       socklen_t len = sizeof(*sin);
+
+       return nfs_name_to_address(hostname, AF_INET,
+                                       (struct sockaddr *)sin, &len);
 }
 
 /*