s3:smb2_server: split out a smb2_validate_sequence_number() function

metze
(similar to commit 984fdaf9149d96d0d28600443981d87d13eb355c)

diff --git a/source3/smbd/smb2_server.c b/source3/smbd/smb2_server.c
index de4b93abc374318a117c44693f41ba6fbe6e5a1c..bbb342b018f97a249c4d4a31e9b2d81dd32fe508 100644 (file)
--- a/source3/smbd/smb2_server.c
+++ b/source3/smbd/smb2_server.c
@@ -298,30 +298,83 @@ static NTSTATUS smbd_smb2_request_create(struct smbd_server_connection *sconn,
        return NT_STATUS_OK;
 }
 
+static bool smb2_validate_sequence_number(struct smbd_server_connection *sconn,
+                                         uint64_t message_id, uint64_t seq_id)
+{
+       struct bitmap *credits_bm = sconn->smb2.credits_bitmap;
+       unsigned int offset;
+
+       if (seq_id < sconn->smb2.seqnum_low) {
+               DEBUG(0,("smb2_validate_sequence_number: bad message_id "
+                       "%llu (sequence id %llu) (low = %llu, max = %lu)\n",
+                       (unsigned long long)message_id,
+                       (unsigned long long)seq_id,
+                       (unsigned long long)sconn->smb2.seqnum_low,
+                       (unsigned long)sconn->smb2.max_credits));
+               return false;
+       }
+
+       if (seq_id > (sconn->smb2.seqnum_low + sconn->smb2.max_credits)) {
+               DEBUG(0,("smb2_validate_sequence_number: bad message_id "
+                       "%llu (sequence id %llu) (low = %llu, max = %lu)\n",
+                       (unsigned long long)message_id,
+                       (unsigned long long)seq_id,
+                       (unsigned long long)sconn->smb2.seqnum_low,
+                       (unsigned long)sconn->smb2.max_credits));
+               return false;
+       }
+
+       offset = seq_id % sconn->smb2.max_credits;
+
+       if (bitmap_query(credits_bm, offset)) {
+               DEBUG(0,("smb2_validate_sequence_number: duplicate message_id "
+                       "%llu (sequence id %llu) (low = %llu, max = %lu) "
+                       "(bm offset %u)\n",
+                       (unsigned long long)message_id,
+                       (unsigned long long)seq_id,
+                       (unsigned long long)sconn->smb2.seqnum_low,
+                       (unsigned long)sconn->smb2.max_credits,
+                       offset));
+               return false;
+       }
+
+       /* Mark the message_ids as seen in the bitmap. */
+       bitmap_set(credits_bm, offset);
+
+       if (seq_id != sconn->smb2.seqnum_low) {
+               return true;
+       }
+
+       /*
+        * Move the window forward by all the message_id's
+        * already seen.
+        */
+       while (bitmap_query(credits_bm, offset)) {
+               DEBUG(10,("smb2_validate_sequence_number: clearing "
+                         "id %llu (position %u) from bitmap\n",
+                         (unsigned long long)(sconn->smb2.seqnum_low),
+                         offset));
+               bitmap_clear(credits_bm, offset);
+
+               sconn->smb2.seqnum_low += 1;
+               offset = sconn->smb2.seqnum_low % sconn->smb2.max_credits;
+       }
+
+       return true;
+}
+
 static bool smb2_validate_message_id(struct smbd_server_connection *sconn,
                                const uint8_t *inhdr)
 {
        uint64_t message_id = BVAL(inhdr, SMB2_HDR_MESSAGE_ID);
-       struct bitmap *credits_bm = sconn->smb2.credits_bitmap;
        uint16_t opcode = IVAL(inhdr, SMB2_HDR_OPCODE);
-       unsigned int bitmap_offset;
+       bool ok;
 
        if (opcode == SMB2_OP_CANCEL) {
                /* SMB2_CANCEL requests by definition resend messageids. */
                return true;
        }
 
-       if (message_id < sconn->smb2.seqnum_low ||
-                       message_id > (sconn->smb2.seqnum_low +
-                       (sconn->smb2.max_credits))) {
-               DEBUG(0,("smb2_validate_message_id: bad message_id "
-                       "%llu (low = %llu, max = %lu)\n",
-                       (unsigned long long)message_id,
-                       (unsigned long long)sconn->smb2.seqnum_low,
-                       (unsigned long)sconn->smb2.max_credits ));
-               return false;
-       }
-
        if (sconn->smb2.credits_granted == 0) {
                DEBUG(0,("smb2_validate_message_id: client used more "
                         "credits than granted message_id (%llu)\n",
@@ -329,34 +382,20 @@ static bool smb2_validate_message_id(struct smbd_server_connection *sconn,
                return false;
        }
 
-       /* client just used a credit. */
-       sconn->smb2.credits_granted -= 1;
+       DEBUG(11, ("smb2_validate_message_id: mid %llu, credits_granted %llu, "
+                  "max_credits %llu, seqnum_low: %llu\n",
+                  (unsigned long long) message_id,
+                  (unsigned long long) sconn->smb2.credits_granted,
+                  (unsigned long long) sconn->smb2.max_credits,
+                  (unsigned long long) sconn->smb2.seqnum_low));
 
-       /* Mark the message_id as seen in the bitmap. */
-       bitmap_offset = message_id % sconn->smb2.max_credits;
-       if (bitmap_query(credits_bm, bitmap_offset)) {
-               DEBUG(0,("smb2_validate_message_id: duplicate message_id "
-                       "%llu (bm offset %u)\n",
-                       (unsigned long long)message_id,
-                       bitmap_offset));
+       ok = smb2_validate_sequence_number(sconn, message_id, message_id);
+       if (!ok) {
                return false;
        }
-       bitmap_set(credits_bm, bitmap_offset);
 
-       if (message_id == sconn->smb2.seqnum_low) {
-               /* Move the window forward by all the message_id's
-                  already seen. */
-               while (bitmap_query(credits_bm, bitmap_offset)) {
-                       DEBUG(10,("smb2_validate_message_id: clearing "
-                               "id %llu (position %u) from bitmap\n",
-                               (unsigned long long)(sconn->smb2.seqnum_low),
-                               bitmap_offset ));
-                       bitmap_clear(credits_bm, bitmap_offset);
-                       sconn->smb2.seqnum_low += 1;
-                       bitmap_offset = sconn->smb2.seqnum_low %
-                               sconn->smb2.max_credits;
-               }
-       }
+       /* substract used credits */
+       sconn->smb2.credits_granted -= 1;
 
        return true;
 }