Introduce a new DNS resolver function in utils/mount/network.c that uses
authorChuck Lever <chuck.lever@oracle.com>
Tue, 15 Jul 2008 16:02:42 +0000 (12:02 -0400)
committerSteve Dickson <steved@redhat.com>
Tue, 15 Jul 2008 16:02:42 +0000 (12:02 -0400)
getaddrinfo(3), which supports AF_INET6, to resolve host names.

Replace the guts of nfs_gethostbyname() with a call to the new function.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>
utils/mount/network.c
utils/mount/network.h

index ab7f6d0..30a4d40 100644 (file)
@@ -144,32 +144,72 @@ static const unsigned long probe_mnt3_first[] = {
 };
 
 /**
+ * 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 *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);
 }
 
 /*
index 99ecc1e..70a91af 100644 (file)
@@ -48,6 +48,8 @@ static const struct timeval RETRY_TIMEOUT = { 3, 0 };
 
 int probe_bothports(clnt_addr_t *, clnt_addr_t *);
 int nfs_gethostbyname(const char *, struct sockaddr_in *);
+int nfs_name_to_address(const char *, const sa_family_t,
+               struct sockaddr *, socklen_t *);
 int get_client_address(struct sockaddr_in *, struct sockaddr_in *);
 int nfs_call_umount(clnt_addr_t *, dirpath *);
 int clnt_ping(struct sockaddr_in *, const unsigned long,