example: add argument for device name

README.md

@@ -4,31 +4,30 @@ Minimal working examples for RDMA: standalone server and client and library for
 
 ## Configuring an RDMA interface
 
-In order to run this RDMA example, you will need to create a RDMA interface on two virtual machines:
+In order to run this RDMA example, you will need to create a RDMA interface on two virtual machines.
+For instance, to use RoCE (RDMA over Converged Ethernet) on interface `enp1s0`:
 
 ```bash
 modprobe rdma_rxe
 rdma link add rxe0 type rxe netdev enp1s0
-rdma link show
 mkdir -p /sys/kernel/config/rdma_cm/rxe0
 ```
 
 ## Standalone server and client
 
 The provided `rdma_standalone` example allows reading the memory of one computer from another one.
-
 On one machine, run the server program, which will read content to be put in the shared memory from STDIN:
 
 ```bash
 make install
-rdma_standalone < README.md
+rdma_standalone -d rxe0 < README.md
 ```
 
 The other machine will act as a client, so we need to pass it the IP address of the server:
 
 ```bash
 make install
-rdma_standalone -c 192.168.16.10 < Makefile
+rdma_standalone -d rxe0 -c 192.168.16.10 < Makefile
 ```
 
 The client should (almost) immediately display the content of `README.md`, and the server the content of `Makefile`.

example/rdma_standalone.c

@@ -38,13 +38,22 @@ int main(int argc, char *argv[]) {
 	pthread_t serve_mr_td;
 	struct ServeMrThreadContext serve_mr_td_ctx;
 
+	size_t remote_host_size;
+	size_t device_name_size;
+	int allocated_size;
 	int server_socket;
-	char remote_host[16];
+	int opt;
+	char *remote_host;
+	char *device_name;
 	char in_mr_fc;
+	bool is_client;
 	bool result;
 
-	int allocated_size = 16384 * sizeof(char);
-	bool is_client = false;
+	// Preallocate some variables
+	allocated_size = 16384 * sizeof(char);
+	remote_host = NULL;
+	device_name = NULL;
+	is_client = false;
 
 	srand48(getpid() * time(NULL));
 	result = common_hashtable_initialize(&mr_mgr, 33);
@@ -56,14 +65,26 @@ int main(int argc, char *argv[]) {
 	/******************************
 	 **** Arguments processing ****
 	 ******************************/
-	// Detect if a server was given; if any, act as a client
-	if(argc >= 3) {
-		if(strcmp(argv[1], "-c") == 0) {
-			strcpy((void *) remote_host, (void *) argv[2]);
+	while((opt = getopt(argc, argv, "c:d:")) != -1) {
+		// Detect if a server was given; if any, act as a client
+		if(opt == 'c') {
+			remote_host_size = strlen(optarg) + 1;
+			remote_host = (char *) malloc(remote_host_size * sizeof(char));
+			strcpy(remote_host, optarg);
+
 			is_client = true;
+		} else if(opt == 'd') {
+			device_name_size = strlen(optarg) + 1;
+			device_name = (char *) malloc(device_name_size * sizeof(char));
+			strcpy(device_name, optarg);
 		}
 	}
 
+	if(device_name == NULL) {
+		fprintf(stderr, "Device name is mandatory: use option `-d`\n");
+		return -1;
+	}
+
 	// Set up remote address
 	if(is_client) {
 		memset(&server_hints, 0, sizeof(struct addrinfo));
@@ -79,7 +100,7 @@ int main(int argc, char *argv[]) {
 	/******************************
 	 ***** RDMA initialization ****
 	 ******************************/
-	result = capulet_rdma_ib_initialize_device(&rdma_ctx, "rxe0");
+	result = capulet_rdma_ib_initialize_device(&rdma_ctx, device_name);
 	if(!result) {
 		fprintf(stderr, "Device initialization failed\n");
 		return -1;