include/ipc: Simplify IPC endpoint API

The current API of the ipc module expects the user to create an ipc_msg
and send that using the ipc_endpoint_send() function, however there is
nothing useful that can be done with an ipc_msg besides sending it, so
it makes no sense to have the user create the ipc_msg themselves.
Further, the ipc_endpoint_recv() function will return any received
ipc_msg to the user, including invalid or unauthenticated messages.
This commit changes the IPC endpoint API so that the user can pass the
data they intend to send right to ipc_endpoint_send() without having
to call ipc_msg_new(). Since ipc_msg_new() is not intended to be used
by the user directly, it is removed from the public API of the ipc
module.
Further, the ipc_endpoint_recv() function is modified to return only
valid, authenticated messages to the caller.

diff --git a/include/ipc.sh b/include/ipc.sh
index a48e8c129d55ba0443f29e92be74abb12e75104d..c289a9104e4e368caa51e7975fd4c1571db79722 100644 (file)
--- a/include/ipc.sh
+++ b/include/ipc.sh
@@ -209,7 +209,7 @@ EOF
        return 0
 }
 
-ipc_msg_new() {
+_ipc_msg_new() {
        local source="$1"
        local destination="$2"
        local data_raw="$3"
@@ -410,10 +410,17 @@ _ipc_endpoint_get() {
 }
 
 ipc_endpoint_send() {
-       local endpoint="$1"
-       local msg="$2"
+       local source="$1"
+       local destination="$2"
+       local data="$3"
+
+       local msg
+
+       if ! msg=$(_ipc_msg_new "$source" "$destination" "$data"); then
+               return 1
+       fi
 
-       if ! _ipc_endpoint_put "$endpoint" "$msg"; then
+       if ! _ipc_endpoint_put "$destination" "$msg"; then
                return 1
        fi
 
@@ -424,12 +431,53 @@ ipc_endpoint_recv() {
        local endpoint="$1"
        local -i timeout="$2"
 
-       local msg
+       local -i start
 
-       if ! msg=$(_ipc_endpoint_get "$endpoint" "$timeout"); then
-               return 1
+       if (( $# < 2 )); then
+               timeout=-1
        fi
 
-       echo "$msg"
-       return 0
+       if ! start=$(date +"%s"); then
+               return 2
+       fi
+
+       while true; do
+               local msg
+               local -i elapsed
+               local -i remaining
+
+               remaining="$timeout"
+
+               if (( timeout > 0 )); then
+                       local now
+
+                       if ! now=$(date +"%s"); then
+                               return 2
+                       fi
+
+                       elapsed=$((now - start))
+                       remaining=$((timeout - elapsed))
+
+                       # Remaining must not be negative because _ipc_endpoint_get() takes
+                       # that to mean "block (possibly forever) until a message arrives"
+                       if (( remaining < 0 )); then
+                               remaining=0
+                       fi
+               fi
+
+               if msg=$(_ipc_endpoint_get "$endpoint" "$remaining"); then
+                       if _ipc_msg_validate "$msg"; then
+                               echo "$msg"
+                               return 0
+                       fi
+
+                       log_info "Dropping invalid message on $endpoint"
+               fi
+
+               if (( remaining == 0 )); then
+                       break
+               fi
+       done
+
+       return 1
 }