Made changes to README instructions and cclient error checking.

Signed-off-by: phansGithub <[email protected]>

pkg/cclient/README.md

@@ -1,36 +1,46 @@
 # Compiling the C Library
 
-## Creating the .h and the .so files:
+## Creating the shared library and header files:
 
+```cmd
+go build -o lib_udsclient.so -buildmode=c-shared cclient.go
+```
+- this creates the header and shared library files from the cclient.go file.
 
-```go build -o lib_udsclient.so -buildmode=c-shared cclient.go```
-	- this creates .h and .so files from the cclient.go file.
-
-
-## Creating the .h and the .a files:
-
-```go build -o lib_udsclient.a -buildmode=c-archive ./cclient.go```
-	- this creates .h and .a files
-
+## Creating the the static library and header files:
 
+```cmd
+go build -o lib_udsclient.a -buildmode=c-archive ./cclient.go
+```
+- this creates the shared library and header files
 
 ## Usage
 
-After creating the .h and/or the .a and the .o files as described in the previous steps,
+After creating the library and header files as described in the previous steps,
 this is how to use the functions generated by cgo
 
-``` char* GetUdsClientVersion()```
-This returns the version of our handshake on your local machine/client.
+```c
+char* GetUdsClientVersion()
+``` 
+This returns the version of the handshake on your local machine/client.
 
-```char* GetUdsServerVersion()```
-This returns the version of our handshake on the server/host.
+```c
+char* GetUdsServerVersion()
+``` 
+This returns the version of the handshake on the server/host.
 
-```int RequestXskMapFd(char* device)```
-This requests an Xsk map Fd for a specifed device.
+```c
+int RequestXskMapFd(char* device)
+``` 
+This requests an xskmap Fd for a specified device.
 
-```int RequestBusyPoll(int busyTimeout, int busyBudget, int fd)```
+```c
+int RequestBusyPoll(int busyTimeout, int busyBudget, int fd)
+``` 
 This requests a busy poll for a specific device by using it's fd, and specifying a timeout and a budget.
 
-```void CleanUpConnection()```
+```c
+void CleanUpConnection()
+``` 
 After all the other functions are called, this needs to be called after all the work you need to do is done,
-so that the connection to the Uds can be cleaned up.
+so that the connection to the UDS can be cleaned up.

pkg/cclient/cclient.go

@@ -24,7 +24,7 @@ func GetUdsClientVersion() *C.char {
 }
 
 /*
-ServerVersion is an exported version for c of goclient's GetServerVersion()
+ServerVersion is an exported version for c of the goclient GetServerVersion()
 */
 //export GetUdsServerVersion
 func GetUdsServerVersion() *C.char {
@@ -41,36 +41,43 @@ func GetUdsServerVersion() *C.char {
 }
 
 /*
-GetXskMapFd is an exported version for c of goclient's XskMapFd()
+GetXskMapFd is an exported version for c of the goclient XskMapFd()
 */
 //export RequestXskMapFd
 func RequestXskMapFd(device *C.char) (fd C.int) {
-	fdVal, function, err := goclient.RequestXSKmapFD(C.GoString(device))
-	fd = C.int(fdVal)
-	if err != nil {
-		fmt.Fprintln(os.Stderr, err.Error())
-		function()
-		return -1
-	}
+	if device != nil {
+		fdVal, function, err := goclient.RequestXSKmapFD(C.GoString(device))
+		fd = C.int(fdVal)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err.Error())
+			function()
+			return -1
+		}
 
-	cleaner = function
+		cleaner = function
+		return fd
+	}
 
-	return fd
+	return -1
 }
 
 /*
-RequestBusyPoll is an exported version for c of goclient's RequestBusyPoll()
+RequestBusyPoll is an exported version for c of the goclient RequestBusyPoll()
 */
 //export RequestBusyPoll
 func RequestBusyPoll(busyTimeout, busyBudget, fd C.int) C.int {
-	function, err := goclient.RequestBusyPoll(int(busyTimeout), int(busyBudget), int(fd))
-	if err != nil {
-		fmt.Fprintln(os.Stderr, err.Error())
-		function()
-		return -1
+	timeout, budget, fdInt := int(busyTimeout), int(busyBudget), int(fd)
+	if timeout > -1 && budget > -1 && fdInt > -1 {
+		function, err := goclient.RequestBusyPoll(timeout, budget, fdInt)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err.Error())
+			function()
+			return -1
+		}
+		cleaner = function
+		return 0
 	}
-	cleaner = function
-	return 0
+	return -1
 }
 
 /*