cifs: rename cifs_strlcpy_to_host and make it use new functions

Rename cifs_strlcpy_to_host to cifs_strndup since that better describes
what this function really does. Then, convert it to use the new string
conversion and measurement functions that work in units of bytes rather
than wide chars.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>

3 files changed, 52 insertions, 43 deletions

diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c
index 6145125..2a879cf 100644
--- a/fs/cifs/cifs_unicode.c
+++ b/fs/cifs/cifs_unicode.c
@@ -243,3 +243,41 @@ cifs_strtoUCS(__le16 *to, const char *from, int len,
 	return i;
 }
 
+/*
+ * cifs_strndup - copy a string from wire format to the local codepage
+ * @src - source string
+ * @maxlen - don't walk past this many bytes in the source string
+ * @is_unicode - is this a unicode string?
+ * @codepage - destination codepage
+ *
+ * Take a string given by the server, convert it to the local codepage and
+ * put it in a new buffer. Returns a pointer to the new string or NULL on
+ * error.
+ */
+char *
+cifs_strndup(const char *src, const int maxlen, const bool is_unicode,
+	     const struct nls_table *codepage)
+{
+	int len;
+	char *dst;
+
+	if (is_unicode) {
+		len = cifs_ucs2_bytes((__le16 *) src, maxlen, codepage);
+		len += nls_nullsize(codepage);
+		dst = kmalloc(len, GFP_KERNEL);
+		if (!dst)
+			return NULL;
+		cifs_from_ucs2(dst, (__le16 *) src, len, maxlen, codepage,
+			       false);
+	} else {
+		len = strnlen(src, maxlen);
+		len++;
+		dst = kmalloc(len, GFP_KERNEL);
+		if (!dst)
+			return NULL;
+		strlcpy(dst, src, len);
+	}
+
+	return dst;
+}
+
diff --git a/fs/cifs/cifs_unicode.h b/fs/cifs/cifs_unicode.h
index 1857f5f..e620f0b 100644
--- a/fs/cifs/cifs_unicode.h
+++ b/fs/cifs/cifs_unicode.h
@@ -78,6 +78,8 @@ int cifs_ucs2_bytes(const __le16 *from, int maxbytes,
 		    const struct nls_table *codepage);
 int cifs_strfromUCS_le(char *, const __le16 *, int, const struct nls_table *);
 int cifs_strtoUCS(__le16 *, const char *, int, const struct nls_table *);
+char *cifs_strndup(const char *src, const int maxlen, const bool is_unicode,
+		   const struct nls_table *codepage);
 #endif
 
 /*
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index cadacae..f158483 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -81,41 +81,6 @@ static struct {
 #endif /* CONFIG_CIFS_WEAK_PW_HASH */
 #endif /* CIFS_POSIX */
 
-/* Allocates buffer into dst and copies smb string from src to it.
- * caller is responsible for freeing dst if function returned 0.
- * returns:
- * 	on success - 0
- *	on failure - errno
- */
-static int
-cifs_strlcpy_to_host(char **dst, const char *src, const int maxlen,
-		 const bool is_unicode, const struct nls_table *nls_codepage)
-{
-	int plen;
-
-	if (is_unicode) {
-		plen = UniStrnlen((wchar_t *)src, maxlen);
-		*dst = kmalloc((4 * plen) + 2, GFP_KERNEL);
-		if (!*dst)
-			goto cifs_strlcpy_to_host_ErrExit;
-		cifs_strfromUCS_le(*dst, (__le16 *)src, plen, nls_codepage);
-		(*dst)[plen] = 0;
-		(*dst)[plen+1] = 0; /* needed for Unicode */
-	} else {
-		plen = strnlen(src, maxlen);
-		*dst = kmalloc(plen + 2, GFP_KERNEL);
-		if (!*dst)
-			goto cifs_strlcpy_to_host_ErrExit;
-		strlcpy(*dst, src, plen);
-	}
-	return 0;
-
-cifs_strlcpy_to_host_ErrExit:
-	cERROR(1, ("Failed to allocate buffer for string\n"));
-	return -ENOMEM;
-}
-
-
 /* Mark as invalid, all open files on tree connections since they
    were closed when session to server was lost */
 static void mark_open_files_invalid(struct cifsTconInfo *pTcon)
@@ -4008,20 +3973,24 @@ parse_DFS_referrals(TRANSACTION2_GET_DFS_REFER_RSP *pSMBr,
 		/* copy DfsPath */
 		temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
 		max_len = data_end - temp;
-		rc = cifs_strlcpy_to_host(&(node->path_name), temp,
-					max_len, is_unicode, nls_codepage);
-		if (rc)
+		node->path_name = cifs_strndup(temp, max_len, is_unicode,
+					       nls_codepage);
+		if (IS_ERR(node->path_name)) {
+			rc = PTR_ERR(node->path_name);
+			node->path_name = NULL;
 			goto parse_DFS_referrals_exit;
+		}
 
 		/* copy link target UNC */
 		temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
 		max_len = data_end - temp;
-		rc = cifs_strlcpy_to_host(&(node->node_name), temp,
-					max_len, is_unicode, nls_codepage);
-		if (rc)
+		node->node_name = cifs_strndup(temp, max_len, is_unicode,
+					       nls_codepage);
+		if (IS_ERR(node->node_name)) {
+			rc = PTR_ERR(node->node_name);
+			node->node_name = NULL;
 			goto parse_DFS_referrals_exit;
-
-		ref += le16_to_cpu(ref->Size);
+		}
 	}
 
 parse_DFS_referrals_exit: