s3-nmbd: Fix netbios name truncation.

Try and cope with truncation more intelligently.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=10896

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

diff --git a/source3/nmbd/nmbd_nameregister.c b/source3/nmbd/nmbd_nameregister.c
index 71c4751d7c1d0cf27dcc2e37b5c58fd532a325cc..8b078e6859af3f92384c1625d5896b4158184576 100644 (file)
--- a/source3/nmbd/nmbd_nameregister.c
+++ b/source3/nmbd/nmbd_nameregister.c
@@ -482,17 +482,77 @@ void register_name(struct subnet_record *subrec,
 {
        struct nmb_name nmbname;
        nstring nname;
+       size_t converted_size;
 
        errno = 0;
-       push_ascii_nstring(nname, name);
-        if (errno == E2BIG) {
-               unstring tname;
-               pull_ascii_nstring(tname, sizeof(tname), nname);
-               DEBUG(0,("register_name: NetBIOS name %s is too long. Truncating to %s\n",
-                       name, tname));
-               make_nmb_name(&nmbname, tname, type);
-       } else {
+       converted_size = push_ascii_nstring(nname, name);
+       if (converted_size != (size_t)-1) {
+               /* Success. */
                make_nmb_name(&nmbname, name, type);
+       } else if (errno == E2BIG) {
+               /*
+                * Name converted to CH_DOS is too large.
+                * try to truncate.
+                */
+               char *converted_str_dos = NULL;
+               char *converted_str_unix = NULL;
+               bool ok;
+
+               converted_size = 0;
+
+               ok = convert_string_talloc(talloc_tos(),
+                               CH_UNIX,
+                               CH_DOS,
+                               name,
+                               strlen(name)+1,
+                               &converted_str_dos,
+                               &converted_size);
+               if (!ok) {
+                       DEBUG(0,("register_name: NetBIOS name %s cannot be "
+                               "converted. Failing to register name.\n",
+                               name));
+                       return;
+               }
+
+               /*
+                * As it's now CH_DOS codepage
+                * we truncate by writing '\0' at
+                * MAX_NETBIOSNAME_LEN-1 and then
+                * convert back to CH_UNIX which we
+                * need for the make_nmb_name() call.
+                */
+               if (converted_size >= MAX_NETBIOSNAME_LEN) {
+                       converted_str_dos[MAX_NETBIOSNAME_LEN-1] = '\0';
+               }
+
+               ok = convert_string_talloc(talloc_tos(),
+                               CH_DOS,
+                               CH_UNIX,
+                               converted_str_dos,
+                               strlen(converted_str_dos)+1,
+                               &converted_str_unix,
+                               &converted_size);
+               if (!ok) {
+                       DEBUG(0,("register_name: NetBIOS name %s cannot be "
+                               "converted back to CH_UNIX. "
+                               "Failing to register name.\n",
+                               converted_str_dos));
+                       TALLOC_FREE(converted_str_dos);
+                       return;
+               }
+
+               make_nmb_name(&nmbname, converted_str_unix, type);
+
+               TALLOC_FREE(converted_str_dos);
+               TALLOC_FREE(converted_str_unix);
+       } else {
+               /*
+                * Generic conversion error. Fail to register.
+                */
+               DEBUG(0,("register_name: NetBIOS name %s cannot be "
+                       "converted (%s). Failing to register name.\n",
+                       name, strerror(errno)));
+               return;
        }
 
        /* Always set the NB_ACTIVE flag on the name we are