File names with trailing period or space need special case conversion

POSIX allows files with trailing spaces or a trailing period but
SMB3 does not, so convert these using the normal Services For Mac
mapping as we do for other reserved characters such as
	: < > | ? *
This is similar to what Macs do for the same problem over SMB3.

CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <steve.french@primarydata.com>
Acked-by: Pavel Shilovsky <pshilovsky@samba.org>

2 files changed, 31 insertions, 4 deletions

diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c
index 5a53ac6b1e02..02b071bf3732 100644
--- a/fs/cifs/cifs_unicode.c
+++ b/fs/cifs/cifs_unicode.c
@@ -101,6 +101,12 @@ convert_sfm_char(const __u16 src_char, char *target)
         case SFM_SLASH:
                 *target = '\\';
                 break;
+        case SFM_SPACE:
+                *target = ' ';
+                break;
+        case SFM_PERIOD:
+                *target = '.';
+                break;
         default:
                 return false;
         }
@@ -404,7 +410,7 @@ static __le16 convert_to_sfu_char(char src_char)
         return dest_char;
 }
 
-static __le16 convert_to_sfm_char(char src_char)
+static __le16 convert_to_sfm_char(char src_char, bool end_of_string)
 {
         __le16 dest_char;
 
@@ -427,6 +433,18 @@ static __le16 convert_to_sfm_char(char src_char)
         case '|':
                 dest_char = cpu_to_le16(SFM_PIPE);
                 break;
+        case '.':
+                if (end_of_string)
+                        dest_char = cpu_to_le16(SFM_PERIOD);
+                else
+                        dest_char = 0;
+                break;
+        case ' ':
+                if (end_of_string)
+                        dest_char = cpu_to_le16(SFM_SPACE);
+                else
+                        dest_char = 0;
+                break;
         default:
                 dest_char = 0;
         }
@@ -469,9 +487,16 @@ cifsConvertToUTF16(__le16 *target, const char *source, int srclen,
                 /* see if we must remap this char */
                 if (map_chars == SFU_MAP_UNI_RSVD)
                         dst_char = convert_to_sfu_char(src_char);
-                else if (map_chars == SFM_MAP_UNI_RSVD)
-                        dst_char = convert_to_sfm_char(src_char);
-                else
+                else if (map_chars == SFM_MAP_UNI_RSVD) {
+                        bool end_of_string;
+
+                        if (i == srclen - 1)
+                                end_of_string = true;
+                        else
+                                end_of_string = false;
+
+                        dst_char = convert_to_sfm_char(src_char, end_of_string);
+                } else
                         dst_char = 0;
                 /*
                  * FIXME: We can not handle remapping backslash (UNI_SLASH)
diff --git a/fs/cifs/cifs_unicode.h b/fs/cifs/cifs_unicode.h
index bdc52cb9a676..479bc0a941f3 100644
--- a/fs/cifs/cifs_unicode.h
+++ b/fs/cifs/cifs_unicode.h
@@ -64,6 +64,8 @@
 #define SFM_LESSTHAN    ((__u16) 0xF023)
 #define SFM_PIPE        ((__u16) 0xF027)
 #define SFM_SLASH       ((__u16) 0xF026)
+#define SFM_PERIOD      ((__u16) 0xF028)
+#define SFM_SPACE       ((__u16) 0xF029)
 
 /*
  * Mapping mechanism to use when one of the seven reserved characters is