tipc: add SYN bit to connection setup messages

Messages intended for intitating a connection are currently
indistinguishable from regular datagram messages. The TIPC
protocol specification defines bit 17 in word 0 as a SYN bit
to allow sanity check of such messages in the listening socket,
but this has so far never been implemented.

We do that in this commit.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jon Maloy 2018-09-28 20:23:21 +02:00 committed by David S. Miller
parent 39fdc9c71f
commit 25b9221b95
3 changed files with 22 additions and 5 deletions

View File

@ -216,6 +216,16 @@ static inline void msg_set_non_seq(struct tipc_msg *m, u32 n)
msg_set_bits(m, 0, 20, 1, n);
}
static inline int msg_is_syn(struct tipc_msg *m)
{
return msg_bits(m, 0, 17, 1);
}
static inline void msg_set_syn(struct tipc_msg *m, u32 d)
{
msg_set_bits(m, 0, 17, 1, d);
}
static inline int msg_dest_droppable(struct tipc_msg *m)
{
return msg_bits(m, 0, 19, 1);

View File

@ -45,6 +45,7 @@
/* Optional capabilities supported by this code version
*/
enum {
TIPC_SYN_BIT = (1),
TIPC_BCAST_SYNCH = (1 << 1),
TIPC_BCAST_STATE_NACK = (1 << 2),
TIPC_BLOCK_FLOWCTL = (1 << 3),
@ -53,7 +54,8 @@ enum {
TIPC_LINK_PROTO_SEQNO = (1 << 6)
};
#define TIPC_NODE_CAPABILITIES (TIPC_BCAST_SYNCH | \
#define TIPC_NODE_CAPABILITIES (TIPC_SYN_BIT | \
TIPC_BCAST_SYNCH | \
TIPC_BCAST_STATE_NACK | \
TIPC_BCAST_RCAST | \
TIPC_BLOCK_FLOWCTL | \

View File

@ -1319,6 +1319,7 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
tsk->conn_type = dest->addr.name.name.type;
tsk->conn_instance = dest->addr.name.name.instance;
}
msg_set_syn(hdr, 1);
}
seq = &dest->addr.nameseq;
@ -1478,6 +1479,7 @@ static void tipc_sk_finish_conn(struct tipc_sock *tsk, u32 peer_port,
struct net *net = sock_net(sk);
struct tipc_msg *msg = &tsk->phdr;
msg_set_syn(msg, 0);
msg_set_destnode(msg, peer_node);
msg_set_destport(msg, peer_port);
msg_set_type(msg, TIPC_CONN_MSG);
@ -2006,6 +2008,9 @@ static bool tipc_sk_filter_connect(struct tipc_sock *tsk, struct sk_buff *skb)
return false;
case TIPC_LISTEN:
/* Accept only SYN message */
if (!msg_is_syn(hdr) &&
tipc_node_get_capabilities(net, onode) & TIPC_SYN_BIT)
return false;
if (!con_msg && !err)
return true;
return false;