diff options
| -rw-r--r-- | net/tipc/link.c | 89 |
1 files changed, 77 insertions, 12 deletions
diff --git a/net/tipc/link.c b/net/tipc/link.c index 087379366d3c..2a26a16e269f 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -1785,6 +1785,56 @@ static struct sk_buff *link_insert_deferred_queue(struct link *l_ptr, return buf; } +/** + * 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, LONG_H_SIZE, DIR_MSG_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 (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); +} + void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr) { read_lock_bh(&tipc_net_lock); @@ -1794,9 +1844,9 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr) struct link *l_ptr; struct sk_buff *crs; struct sk_buff *buf = head; - struct tipc_msg *msg = buf_msg(buf); - u32 seq_no = msg_seqno(msg); - u32 ackd = msg_ack(msg); + struct tipc_msg *msg; + u32 seq_no; + u32 ackd; u32 released = 0; int type; @@ -1804,12 +1854,11 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr) TIPC_SKB_CB(buf)->handle = b_ptr; head = head->next; - if (unlikely(msg_version(msg) != TIPC_VERSION)) + + /* Ensure message is well-formed */ + + if (unlikely(!link_recv_buf_validate(buf))) goto cont; -#if 0 - if (msg_user(msg) != LINK_PROTOCOL) -#endif - msg_dbg(msg,"<REC<"); /* Ensure message data is a single contiguous unit */ @@ -1817,6 +1866,10 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr) goto cont; } + /* Handle arrival of a non-unicast link message */ + + msg = buf_msg(buf); + if (unlikely(msg_non_seq(msg))) { link_recv_non_seq(buf); continue; @@ -1826,19 +1879,26 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr) (msg_destnode(msg) != tipc_own_addr))) goto cont; + /* Locate unicast link endpoint that should handle message */ + n_ptr = tipc_node_find(msg_prevnode(msg)); if (unlikely(!n_ptr)) goto cont; - tipc_node_lock(n_ptr); + l_ptr = n_ptr->links[b_ptr->identity]; if (unlikely(!l_ptr)) { tipc_node_unlock(n_ptr); goto cont; } - /* - * Release acked messages - */ + + /* Validate message sequence number info */ + + seq_no = msg_seqno(msg); + ackd = msg_ack(msg); + + /* Release acked messages */ + if (less(n_ptr->bclink.acked, msg_bcast_ack(msg))) { if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported) tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg)); @@ -1857,6 +1917,9 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr) l_ptr->first_out = crs; l_ptr->out_queue_size -= released; } + + /* Try sending any messages link endpoint has pending */ + if (unlikely(l_ptr->next_out)) tipc_link_push_queue(l_ptr); if (unlikely(!list_empty(&l_ptr->waiting_ports))) @@ -1866,6 +1929,8 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr) tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0); } + /* Now (finally!) process the incoming message */ + protocol_check: if (likely(link_working_working(l_ptr))) { if (likely(seq_no == mod(l_ptr->next_in_no))) { |