summaryrefslogtreecommitdiff
path: root/net/tipc/msg.c
diff options
context:
space:
mode:
authorJon Paul Maloy <jon.maloy@ericsson.com>2014-06-25 20:41:36 -0500
committerDavid S. Miller <davem@davemloft.net>2014-06-27 12:50:55 -0700
commit5a379074a7dd6d288ec9e6472769ba0e0c54dd85 (patch)
tree53ef118e4b5276de35a522202bcb739138ba4e83 /net/tipc/msg.c
parent8db1bae30b7cd3c3abc05f467d0f7c69b33b80e9 (diff)
tipc: introduce message evaluation function
When a message arrives in a node and finds no destination socket, we may need to drop it, reject it, or forward it after a secondary destination lookup. The latter two cases currently results in a code path that is perceived as complex, because it follows a deep call chain via obscure functions such as net_route_named_msg() and net_route_msg(). We now introduce a function, tipc_msg_eval(), that takes the decision about whether such a message should be rejected or forwarded, but leaves it to the caller to actually perform the indicated action. If the decision is 'reject', it is still the task of the recently introduced function tipc_msg_reverse() to take the final decision about whether the message is rejectable or not. In the latter case it drops the message. As a result of this change, we can finally eliminate the function net_route_named_msg(), and hence become independent of net_route_msg(). Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc/msg.c')
-rw-r--r--net/tipc/msg.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
index 6070dd0ec634..7bfc4422bf2c 100644
--- a/net/tipc/msg.c
+++ b/net/tipc/msg.c
@@ -36,6 +36,8 @@
#include "core.h"
#include "msg.h"
+#include "addr.h"
+#include "name_table.h"
#define MAX_FORWARD_SIZE 1024
@@ -370,3 +372,39 @@ exit:
kfree_skb(buf);
return false;
}
+
+/**
+ * tipc_msg_eval: determine fate of message that found no destination
+ * @buf: the buffer containing the message.
+ * @dnode: return value: next-hop node, if message to be forwarded
+ * @err: error code to use, if message to be rejected
+ *
+ * Does not consume buffer
+ * Returns 0 (TIPC_OK) if message ok and we can try again, -TIPC error
+ * code if message to be rejected
+ */
+int tipc_msg_eval(struct sk_buff *buf, u32 *dnode)
+{
+ struct tipc_msg *msg = buf_msg(buf);
+ u32 dport;
+
+ if (msg_type(msg) != TIPC_NAMED_MSG)
+ return -TIPC_ERR_NO_PORT;
+ if (skb_linearize(buf))
+ return -TIPC_ERR_NO_NAME;
+ if (msg_data_sz(msg) > MAX_FORWARD_SIZE)
+ return -TIPC_ERR_NO_NAME;
+ if (msg_reroute_cnt(msg) > 0)
+ return -TIPC_ERR_NO_NAME;
+
+ *dnode = addr_domain(msg_lookup_scope(msg));
+ dport = tipc_nametbl_translate(msg_nametype(msg),
+ msg_nameinst(msg),
+ dnode);
+ if (!dport)
+ return -TIPC_ERR_NO_NAME;
+ msg_incr_reroute_cnt(msg);
+ msg_set_destnode(msg, *dnode);
+ msg_set_destport(msg, dport);
+ return TIPC_OK;
+}