text-based mount: Replace nfs_lookup() with getaddrinfo(3)

Originally I thought it would be best to share the DNS query code
between the legacy mount code and the new text-based code, hence
the introduction of nfs_lookup().  However, it now appears we want
the text-based code to do a little more than take the first address
returned by the query.

So, let's invoke getaddrinfo(3) directly in stropts.c, and save
the returned addrinfo struct until the end of processing.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
index 74224ffdad2a0e477b65b05748384c2d3d51f279..4ffee485f0d0c29f42ffd9eddd1f689d0cba3725 100644 (file)
--- a/utils/mount/stropts.c
+++ b/utils/mount/stropts.c
@@ -49,6 +49,10 @@
 #include "parse_dev.h"
 #include "conffile.h"
 
+#ifndef HAVE_DECL_AI_ADDRCONFIG
+#define AI_ADDRCONFIG  0
+#endif
+
 #ifndef NFS_PROGRAM
 #define NFS_PROGRAM    (100003)
 #endif
@@ -83,8 +87,7 @@ struct nfsmount_info {
                                *node,          /* mounted-on dir */
                                *type;          /* "nfs" or "nfs4" */
        char                    *hostname;      /* server's hostname */
-       union nfs_sockaddr      address;
-       socklen_t               salen;          /* size of server's address */
+       struct addrinfo         *address;       /* server's addresses */
 
        struct mount_options    *options;       /* parsed mount options */
        char                    **extra_opts;   /* string for /etc/mtab */
@@ -333,17 +336,27 @@ static int nfs_set_version(struct nfsmount_info *mi)
  */
 static int nfs_validate_options(struct nfsmount_info *mi)
 {
-       struct sockaddr *sap = &mi->address.sa;
+       struct addrinfo hint = {
+               .ai_protocol    = (int)IPPROTO_UDP,
+               .ai_flags       = AI_ADDRCONFIG,
+       };
        sa_family_t family;
+       int error;
 
        if (!nfs_parse_devname(mi->spec, &mi->hostname, NULL))
                return 0;
 
        if (!nfs_nfs_proto_family(mi->options, &family))
                return 0;
-       mi->salen = sizeof(mi->address);
-       if (!nfs_lookup(mi->hostname, family, sap, &mi->salen))
+
+       hint.ai_family = (int)family;
+       error = getaddrinfo(mi->hostname, NULL, &hint, &mi->address);
+       if (error != 0) {
+               nfs_error(_("%s: Failed to resolve server %s: %s"),
+                       progname, mi->hostname, gai_strerror(error));
+               mi->address = NULL;
                return 0;
+       }
 
        if (!nfs_set_version(mi))
                return 0;
@@ -351,7 +364,8 @@ static int nfs_validate_options(struct nfsmount_info *mi)
        if (!nfs_append_sloppy_option(mi->options))
                return 0;
 
-       if (!nfs_append_addr_option(sap, mi->salen, mi->options))
+       if (!nfs_append_addr_option(mi->address->ai_addr,
+                                       mi->address->ai_addrlen, mi->options))
                return 0;
 
        return 1;
@@ -614,7 +628,7 @@ out_fail:
  */
 static int nfs_try_mount_v4(struct nfsmount_info *mi)
 {
-       struct sockaddr *sap = &mi->address.sa;
+       struct addrinfo *ai = mi->address;
        struct mount_options *options = po_dup(mi->options);
        int result = 0;
 
@@ -642,7 +656,7 @@ static int nfs_try_mount_v4(struct nfsmount_info *mi)
                }
        }
 
-       if (!nfs_append_clientaddr_option(sap, mi->salen, options)) {
+       if (!nfs_append_clientaddr_option(ai->ai_addr, ai->ai_addrlen, options)) {
                errno = EINVAL;
                goto out_fail;
        }
@@ -882,6 +896,7 @@ int nfsmount_string(const char *spec, const char *node, const char *type,
        struct nfsmount_info mi = {
                .spec           = spec,
                .node           = node,
+               .address        = NULL,
                .type           = type,
                .extra_opts     = extra_opts,
                .flags          = flags,
@@ -897,6 +912,7 @@ int nfsmount_string(const char *spec, const char *node, const char *type,
        } else
                nfs_error(_("%s: internal option parsing error"), progname);
 
+       freeaddrinfo(mi.address);
        free(mi.hostname);
        return retval;
 }