cifs: handle hostnames that resolve to same ip in failover

[linux-2.6-microblaze.git] / fs / cifs / misc.c

diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 550ce90..1ec6a55 100644 (file)
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -32,6 +32,9 @@
 #include "cifs_unicode.h"
 #include "smb2pdu.h"
 #include "cifsfs.h"
+#ifdef CONFIG_CIFS_DFS_UPCALL
+#include "dns_resolve.h"
+#endif
 
 extern mempool_t *cifs_sm_req_poolp;
 extern mempool_t *cifs_req_poolp;
@@ -1083,6 +1086,51 @@ void cifs_put_tcp_super(struct super_block *sb)
 }
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
+int match_target_ip(struct TCP_Server_Info *server,
+                   const char *share, size_t share_len,
+                   bool *result)
+{
+       int rc;
+       char *target, *tip = NULL;
+       struct sockaddr tipaddr;
+
+       *result = false;
+
+       target = kzalloc(share_len + 3, GFP_KERNEL);
+       if (!target) {
+               rc = -ENOMEM;
+               goto out;
+       }
+
+       scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share);
+
+       cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2);
+
+       rc = dns_resolve_server_name_to_ip(target, &tip);
+       if (rc < 0)
+               goto out;
+
+       cifs_dbg(FYI, "%s: target ip: %s\n", __func__, tip);
+
+       if (!cifs_convert_address(&tipaddr, tip, strlen(tip))) {
+               cifs_dbg(VFS, "%s: failed to convert target ip address\n",
+                        __func__);
+               rc = -EINVAL;
+               goto out;
+       }
+
+       *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr,
+                                   &tipaddr);
+       cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);
+       rc = 0;
+
+out:
+       kfree(target);
+       kfree(tip);
+
+       return rc;
+}
+
 static void tcon_super_cb(struct super_block *sb, void *arg)
 {
        struct super_cb_data *sd = arg;