[CIFS] Handle legacy servers which return undefined time zone

Signed-off-by: Guenter Kukkukk <linux@kukkukk.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 27 insertions, 1 deletions

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index dcd7087a1ae8..99718591ea29 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -447,6 +447,7 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 #ifdef CONFIG_CIFS_WEAK_PW_HASH 
         } else if((pSMBr->hdr.WordCount == 13)
                         && (pSMBr->DialectIndex == LANMAN_PROT)) {
+                int tmp, adjust;
                 struct lanman_neg_rsp * rsp = (struct lanman_neg_rsp *)pSMBr;
 
                 if((secFlags & CIFSSEC_MAY_LANMAN) || 
@@ -473,11 +474,36 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
                         server->capabilities = CAP_MPX_MODE;
                 }
                 server->timeZone = le16_to_cpu(rsp->ServerTimeZone);
+                tmp = le16_to_cpu(rsp->ServerTimeZone);
+                if (tmp == (int)0xffff) {
+                        /* OS/2 often does not set timezone therefore
+                         * we must use server time to calc time zone.
+                         * Could deviate slightly from the right zone. Not easy
+                         * to adjust, since timezones are not always a multiple
+                         * of 60 (sometimes 30 minutes - are there smaller?)
+                         */
+                        struct timespec ts, utc;
+                        utc = CURRENT_TIME;
+                        ts = cnvrtDosUnixTm(le16_to_cpu(rsp->SrvTime.Date),
+                                                le16_to_cpu(rsp->SrvTime.Time));
+                        cFYI(1,("SrvTime: %d sec since 1970 (utc: %d) diff: %d",
+                                (int)ts.tv_sec, (int)utc.tv_sec, 
+                                (int)(utc.tv_sec - ts.tv_sec)));
+                        tmp = (int)(utc.tv_sec - ts.tv_sec);
+                        adjust = tmp < 0 ? -29 : 29;
+                        tmp = ((tmp + adjust) / 60) * 60;
+                        server->timeZone = tmp;
+                } else {
+                        server->timeZone = tmp * 60; /* also in seconds */
+                }
+                cFYI(1,("server->timeZone: %d seconds", server->timeZone));
+
 
                 /* BB get server time for time conversions and add
                 code to use it and timezone since this is not UTC */    
 
-                if (rsp->EncryptionKeyLength == cpu_to_le16(CIFS_CRYPTO_KEY_SIZE)) {
+                if (rsp->EncryptionKeyLength == 
+                                cpu_to_le16(CIFS_CRYPTO_KEY_SIZE)) {
                         memcpy(server->cryptKey, rsp->EncryptionKey,
                                 CIFS_CRYPTO_KEY_SIZE);
                 } else if (server->secMode & SECMODE_PW_ENCRYPT) {