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-rw-r--r--fs/cifs/dns_resolve.c62
1 files changed, 52 insertions, 10 deletions
diff --git a/fs/cifs/dns_resolve.c b/fs/cifs/dns_resolve.c
index 7cc86c41818..939e256f849 100644
--- a/fs/cifs/dns_resolve.c
+++ b/fs/cifs/dns_resolve.c
@@ -55,6 +55,32 @@ struct key_type key_type_dns_resolver = {
.match = user_match,
};
+/* Checks if supplied name is IP address
+ * returns:
+ * 1 - name is IP
+ * 0 - name is not IP
+ */
+static int is_ip(const char *name)
+{
+ int rc;
+ struct sockaddr_in sin_server;
+ struct sockaddr_in6 sin_server6;
+
+ rc = cifs_inet_pton(AF_INET, name,
+ &sin_server.sin_addr.s_addr);
+
+ if (rc <= 0) {
+ /* not ipv4 address, try ipv6 */
+ rc = cifs_inet_pton(AF_INET6, name,
+ &sin_server6.sin6_addr.in6_u);
+ if (rc > 0)
+ return 1;
+ } else {
+ return 1;
+ }
+ /* we failed translating address */
+ return 0;
+}
/* Resolves server name to ip address.
* input:
@@ -67,8 +93,9 @@ int
dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
{
int rc = -EAGAIN;
- struct key *rkey;
+ struct key *rkey = ERR_PTR(-EAGAIN);
char *name;
+ char *data = NULL;
int len;
if (!ip_addr || !unc)
@@ -97,26 +124,41 @@ dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
memcpy(name, unc+2, len);
name[len] = 0;
+ if (is_ip(name)) {
+ cFYI(1, ("%s: it is IP, skipping dns upcall: %s",
+ __func__, name));
+ data = name;
+ goto skip_upcall;
+ }
+
rkey = request_key(&key_type_dns_resolver, name, "");
if (!IS_ERR(rkey)) {
- len = strlen(rkey->payload.data);
- *ip_addr = kmalloc(len+1, GFP_KERNEL);
- if (*ip_addr) {
- memcpy(*ip_addr, rkey->payload.data, len);
- (*ip_addr)[len] = '\0';
- cFYI(1, ("%s: resolved: %s to %s", __func__,
+ data = rkey->payload.data;
+ cFYI(1, ("%s: resolved: %s to %s", __func__,
rkey->description,
*ip_addr
));
+ } else {
+ cERROR(1, ("%s: unable to resolve: %s", __func__, name));
+ goto out;
+ }
+
+skip_upcall:
+ if (data) {
+ len = strlen(data);
+ *ip_addr = kmalloc(len+1, GFP_KERNEL);
+ if (*ip_addr) {
+ memcpy(*ip_addr, data, len);
+ (*ip_addr)[len] = '\0';
rc = 0;
} else {
rc = -ENOMEM;
}
- key_put(rkey);
- } else {
- cERROR(1, ("%s: unable to resolve: %s", __func__, name));
+ if (!IS_ERR(rkey))
+ key_put(rkey);
}
+out:
kfree(name);
return rc;
}