tipc: move message validation function to msg.c

The function link_buf_validate() is in reality re-entrant and context
independent, and will in later commits be called from several locations.
Therefore, we move it to msg.c, make it outline and rename the it to
tipc_msg_validate().

We also redesign the function to make proper use of pskb_may_pull()

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 57 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 98609fdfb06a..944c8c663a2d 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1048,61 +1048,6 @@ static void link_retrieve_defq(struct tipc_link *link,
 }
 
 /**
- * link_recv_buf_validate - validate basic format of received message
- *
- * This routine ensures a TIPC message has an acceptable header, and at least
- * as much data as the header indicates it should.  The routine also ensures
- * that the entire message header is stored in the main fragment of the message
- * buffer, to simplify future access to message header fields.
- *
- * Note: Having extra info present in the message header or data areas is OK.
- * TIPC will ignore the excess, under the assumption that it is optional info
- * introduced by a later release of the protocol.
- */
-static int link_recv_buf_validate(struct sk_buff *buf)
-{
-        static u32 min_data_hdr_size[8] = {
-                SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE,
-                MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
-                };
-
-        struct tipc_msg *msg;
-        u32 tipc_hdr[2];
-        u32 size;
-        u32 hdr_size;
-        u32 min_hdr_size;
-
-        /* If this packet comes from the defer queue, the skb has already
-         * been validated
-         */
-        if (unlikely(TIPC_SKB_CB(buf)->deferred))
-                return 1;
-
-        if (unlikely(buf->len < MIN_H_SIZE))
-                return 0;
-
-        msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
-        if (msg == NULL)
-                return 0;
-
-        if (unlikely(msg_version(msg) != TIPC_VERSION))
-                return 0;
-
-        size = msg_size(msg);
-        hdr_size = msg_hdr_sz(msg);
-        min_hdr_size = msg_isdata(msg) ?
-                min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
-
-        if (unlikely((hdr_size < min_hdr_size) ||
-                     (size < hdr_size) ||
-                     (buf->len < size) ||
-                     (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
-                return 0;
-
-        return pskb_may_pull(buf, hdr_size);
-}
-
-/**
  * tipc_rcv - process TIPC packets/messages arriving from off-node
  * @net: the applicable net namespace
  * @skb: TIPC packet
@@ -1127,7 +1072,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
 
         while ((skb = __skb_dequeue(&head))) {
                 /* Ensure message is well-formed */
-                if (unlikely(!link_recv_buf_validate(skb)))
+                if (unlikely(!tipc_msg_validate(skb)))
                         goto discard;
 
                 /* Ensure message data is a single contiguous unit */
@@ -1398,7 +1343,6 @@ static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
 
         if (tipc_link_defer_pkt(&l_ptr->deferred_queue, buf)) {
                 l_ptr->stats.deferred_recv++;
-                TIPC_SKB_CB(buf)->deferred = true;
                 if ((skb_queue_len(&l_ptr->deferred_queue) % 16) == 1)
                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
         } else {