cifs: break out decoding of security blob into separate function

...cleanup.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 60 insertions, 49 deletions

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index c1c2006376a1..9b4aea85b15c 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -367,6 +367,56 @@ vt2_err:
         return -EINVAL;
 }
 
+static int
+decode_ext_sec_blob(struct TCP_Server_Info *server, NEGOTIATE_RSP *pSMBr)
+{
+        int     rc = 0;
+        u16     count;
+        char    *guid = pSMBr->u.extended_response.GUID;
+
+        count = get_bcc(&pSMBr->hdr);
+        if (count < SMB1_CLIENT_GUID_SIZE)
+                return -EIO;
+
+        spin_lock(&cifs_tcp_ses_lock);
+        if (server->srv_count > 1) {
+                spin_unlock(&cifs_tcp_ses_lock);
+                if (memcmp(server->server_GUID, guid, SMB1_CLIENT_GUID_SIZE) != 0) {
+                        cifs_dbg(FYI, "server UID changed\n");
+                        memcpy(server->server_GUID, guid, SMB1_CLIENT_GUID_SIZE);
+                }
+        } else {
+                spin_unlock(&cifs_tcp_ses_lock);
+                memcpy(server->server_GUID, guid, SMB1_CLIENT_GUID_SIZE);
+        }
+
+        if (count == SMB1_CLIENT_GUID_SIZE) {
+                server->secType = RawNTLMSSP;
+        } else {
+                count -= SMB1_CLIENT_GUID_SIZE;
+                rc = decode_negTokenInit(
+                        pSMBr->u.extended_response.SecurityBlob, count, server);
+                if (rc != 1)
+                        return -EINVAL;
+
+                /* Make sure server supports what we want to use */
+                switch(server->secType) {
+                case Kerberos:
+                        if (!server->sec_kerberos && !server->sec_mskerberos)
+                                return -EOPNOTSUPP;
+                        break;
+                case RawNTLMSSP:
+                        if (!server->sec_ntlmssp)
+                                return -EOPNOTSUPP;
+                        break;
+                default:
+                        return -EOPNOTSUPP;
+                }
+        }
+
+        return 0;
+}
+
 int
 CIFSSMBNegotiate(const unsigned int xid, struct cifs_ses *ses)
 {
@@ -568,61 +618,22 @@ CIFSSMBNegotiate(const unsigned int xid, struct cifs_ses *ses)
         server->capabilities = le32_to_cpu(pSMBr->Capabilities);
         server->timeAdj = (int)(__s16)le16_to_cpu(pSMBr->ServerTimeZone);
         server->timeAdj *= 60;
-        if (pSMBr->EncryptionKeyLength == CIFS_CRYPTO_KEY_SIZE) {
+
+        if (pSMBr->EncryptionKeyLength == CIFS_CRYPTO_KEY_SIZE)
                 memcpy(ses->server->cryptkey, pSMBr->u.EncryptionKey,
                        CIFS_CRYPTO_KEY_SIZE);
-        } else if ((pSMBr->hdr.Flags2 & SMBFLG2_EXT_SEC ||
+        else if ((pSMBr->hdr.Flags2 & SMBFLG2_EXT_SEC ||
                         server->capabilities & CAP_EXTENDED_SECURITY) &&
-                                (pSMBr->EncryptionKeyLength == 0)) {
-                /* decode security blob */
-                count = get_bcc(&pSMBr->hdr);
-                if (count < 16) {
-                        rc = -EIO;
-                        goto neg_err_exit;
-                }
-                spin_lock(&cifs_tcp_ses_lock);
-                if (server->srv_count > 1) {
-                        spin_unlock(&cifs_tcp_ses_lock);
-                        if (memcmp(server->server_GUID,
-                                   pSMBr->u.extended_response.
-                                   GUID, 16) != 0) {
-                                cifs_dbg(FYI, "server UID changed\n");
-                                memcpy(server->server_GUID,
-                                        pSMBr->u.extended_response.GUID,
-                                        16);
-                        }
-                } else {
-                        spin_unlock(&cifs_tcp_ses_lock);
-                        memcpy(server->server_GUID,
-                               pSMBr->u.extended_response.GUID, 16);
-                }
-
-                if (count == 16) {
-                        server->secType = RawNTLMSSP;
-                } else {
-                        rc = decode_negTokenInit(pSMBr->u.extended_response.
-                                                 SecurityBlob, count - 16,
-                                                 server);
-                        if (rc == 1)
-                                rc = 0;
-                        else
-                                rc = -EINVAL;
-                        if (server->secType == Kerberos) {
-                                if (!server->sec_kerberos &&
-                                                !server->sec_mskerberos)
-                                        rc = -EOPNOTSUPP;
-                        } else if (server->secType == RawNTLMSSP) {
-                                if (!server->sec_ntlmssp)
-                                        rc = -EOPNOTSUPP;
-                        } else
-                                        rc = -EOPNOTSUPP;
-                }
-        } else if (server->sec_mode & SECMODE_PW_ENCRYPT) {
+                                (pSMBr->EncryptionKeyLength == 0))
+                rc = decode_ext_sec_blob(server, pSMBr);
+        else if (server->sec_mode & SECMODE_PW_ENCRYPT)
                 rc = -EIO; /* no crypt key only if plain text pwd */
-                goto neg_err_exit;
-        } else
+        else
                 server->capabilities &= ~CAP_EXTENDED_SECURITY;
 
+        if (rc)
+                goto neg_err_exit;
+
 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 signing_check:
 #endif