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smb3: minor debugging clarifications in rfc1001 len processing

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I ran into some cases where server was returning the wrong length
on frames but I couldn't easily match them to the command in the
network trace (or server logs) since I need the command and/or
multiplex id to find the offending SMB2/SMB3 command.  Add these
two fields to the log message. In the case of padding too much
it may not be a problem in all cases but might have correlated
to a network disconnect case in some problems we have been
looking at. In the case of frame too short is even more important.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
This commit is contained in:
Steve French 2018-08-29 09:22:22 -05:00
parent 5e19697b56
commit 25f2573512
1 changed files with 9 additions and 5 deletions
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14
fs/cifs/smb2misc.c
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@ -248,16 +248,20 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *srvr)
* MacOS server pads after SMB2.1 write response with 3 bytes
* of junk. Other servers match RFC1001 len to actual
* SMB2/SMB3 frame length (header + smb2 response specific data)
* Some windows servers do too when compounding is used.
* Log the server error (once), but allow it and continue
* Some windows servers also pad up to 8 bytes when compounding.
* If pad is longer than eight bytes, log the server behavior
* (once), since may indicate a problem but allow it and continue
* since the frame is parseable.
*/
if (clc_len < len) {
printk_once(KERN_WARNING
"SMB2 server sent bad RFC1001 len %d not %d\n",
len, clc_len);
pr_warn_once(
"srv rsp padded more than expected. Length %d not %d for cmd:%d mid:%llu\n",
len, clc_len, command, mid);
return 0;
}
pr_warn_once(
"srv rsp too short, len %d not %d. cmd:%d mid:%llu\n",
len, clc_len, command, mid);
return 1;
}