examples/pipeline: add message passing mechanism

Add network-based connectivity mechanism for the application to allow
for the exchange of configuration messages through the network as
opposed to local CLI only.

Signed-off-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>

examples/pipeline/Makefile

@@ -5,6 +5,7 @@
 APP = pipeline
 
 # all source are stored in SRCS-y
+SRCS-y += conn.c
 SRCS-y += main.c
 SRCS-y += obj.c
 SRCS-y += thread.c

examples/pipeline/conn.c

@@ -0,0 +1,331 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Intel Corporation
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+#include <sys/socket.h>
+
+#include <sys/epoll.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <errno.h>
+
+#include "conn.h"
+
+#define MSG_CMD_TOO_LONG "Command too long."
+
+struct conn {
+	char *welcome;
+	char *prompt;
+	char *buf;
+	char *msg_in;
+	char *msg_out;
+	size_t buf_size;
+	size_t msg_in_len_max;
+	size_t msg_out_len_max;
+	size_t msg_in_len;
+	int fd_server;
+	int fd_client_group;
+	conn_msg_handle_t msg_handle;
+	void *msg_handle_arg;
+};
+
+struct conn *
+conn_init(struct conn_params *p)
+{
+	struct sockaddr_in server_address;
+	struct conn *conn;
+	int fd_server, fd_client_group, status;
+
+	memset(&server_address, 0, sizeof(server_address));
+
+	/* Check input arguments */
+	if ((p == NULL) ||
+		(p->welcome == NULL) ||
+		(p->prompt == NULL) ||
+		(p->addr == NULL) ||
+		(p->buf_size == 0) ||
+		(p->msg_in_len_max == 0) ||
+		(p->msg_out_len_max == 0) ||
+		(p->msg_handle == NULL))
+		return NULL;
+
+	status = inet_aton(p->addr, &server_address.sin_addr);
+	if (status == 0)
+		return NULL;
+
+	/* Memory allocation */
+	conn = calloc(1, sizeof(struct conn));
+	if (conn == NULL)
+		return NULL;
+
+	conn->welcome = calloc(1, CONN_WELCOME_LEN_MAX + 1);
+	conn->prompt = calloc(1, CONN_PROMPT_LEN_MAX + 1);
+	conn->buf = calloc(1, p->buf_size);
+	conn->msg_in = calloc(1, p->msg_in_len_max + 1);
+	conn->msg_out = calloc(1, p->msg_out_len_max + 1);
+
+	if ((conn->welcome == NULL) ||
+		(conn->prompt == NULL) ||
+		(conn->buf == NULL) ||
+		(conn->msg_in == NULL) ||
+		(conn->msg_out == NULL)) {
+		conn_free(conn);
+		return NULL;
+	}
+
+	/* Server socket */
+	server_address.sin_family = AF_INET;
+	server_address.sin_port = htons(p->port);
+
+	fd_server = socket(AF_INET,
+		SOCK_STREAM | SOCK_NONBLOCK,
+		0);
+	if (fd_server == -1) {
+		conn_free(conn);
+		return NULL;
+	}
+
+	status = bind(fd_server,
+		(struct sockaddr *) &server_address,
+		sizeof(server_address));
+	if (status == -1) {
+		conn_free(conn);
+		close(fd_server);
+		return NULL;
+	}
+
+	status = listen(fd_server, 16);
+	if (status == -1) {
+		conn_free(conn);
+		close(fd_server);
+		return NULL;
+	}
+
+	/* Client group */
+	fd_client_group = epoll_create(1);
+	if (fd_client_group == -1) {
+		conn_free(conn);
+		close(fd_server);
+		return NULL;
+	}
+
+	/* Fill in */
+	strncpy(conn->welcome, p->welcome, CONN_WELCOME_LEN_MAX);
+	strncpy(conn->prompt, p->prompt, CONN_PROMPT_LEN_MAX);
+	conn->buf_size = p->buf_size;
+	conn->msg_in_len_max = p->msg_in_len_max;
+	conn->msg_out_len_max = p->msg_out_len_max;
+	conn->msg_in_len = 0;
+	conn->fd_server = fd_server;
+	conn->fd_client_group = fd_client_group;
+	conn->msg_handle = p->msg_handle;
+	conn->msg_handle_arg = p->msg_handle_arg;
+
+	return conn;
+}
+
+void
+conn_free(struct conn *conn)
+{
+	if (conn == NULL)
+		return;
+
+	if (conn->fd_client_group)
+		close(conn->fd_client_group);
+
+	if (conn->fd_server)
+		close(conn->fd_server);
+
+	free(conn->msg_out);
+	free(conn->msg_in);
+	free(conn->prompt);
+	free(conn->welcome);
+	free(conn);
+}
+
+int
+conn_poll_for_conn(struct conn *conn)
+{
+	struct sockaddr_in client_address;
+	struct epoll_event event;
+	socklen_t client_address_length;
+	int fd_client, status;
+
+	/* Check input arguments */
+	if (conn == NULL)
+		return -1;
+
+	/* Server socket */
+	client_address_length = sizeof(client_address);
+	fd_client = accept4(conn->fd_server,
+		(struct sockaddr *) &client_address,
+		&client_address_length,
+		SOCK_NONBLOCK);
+	if (fd_client == -1) {
+		if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
+			return 0;
+
+		return -1;
+	}
+
+	/* Client group */
+	event.events = EPOLLIN | EPOLLRDHUP | EPOLLHUP;
+	event.data.fd = fd_client;
+
+	status = epoll_ctl(conn->fd_client_group,
+		EPOLL_CTL_ADD,
+		fd_client,
+		&event);
+	if (status == -1) {
+		close(fd_client);
+		return -1;
+	}
+
+	/* Client */
+	status = write(fd_client,
+		conn->welcome,
+		strlen(conn->welcome));
+	if (status == -1) {
+		close(fd_client);
+		return -1;
+	}
+
+	status = write(fd_client,
+		conn->prompt,
+		strlen(conn->prompt));
+	if (status == -1) {
+		close(fd_client);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int
+data_event_handle(struct conn *conn,
+	int fd_client)
+{
+	ssize_t len, i, status;
+
+	/* Read input message */
+
+	len = read(fd_client,
+		conn->buf,
+		conn->buf_size);
+	if (len == -1) {
+		if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
+			return 0;
+
+		return -1;
+	}
+	if (len == 0)
+		return 0;
+
+	/* Handle input messages */
+	for (i = 0; i < len; i++) {
+		if (conn->buf[i] == '\n') {
+			size_t n;
+
+			conn->msg_in[conn->msg_in_len] = 0;
+			conn->msg_out[0] = 0;
+
+			conn->msg_handle(conn->msg_in,
+				conn->msg_out,
+				conn->msg_out_len_max,
+				conn->msg_handle_arg);
+
+			n = strlen(conn->msg_out);
+			if (n) {
+				status = write(fd_client,
+					conn->msg_out,
+					n);
+				if (status == -1)
+					return status;
+			}
+
+			conn->msg_in_len = 0;
+		} else if (conn->msg_in_len < conn->msg_in_len_max) {
+			conn->msg_in[conn->msg_in_len] = conn->buf[i];
+			conn->msg_in_len++;
+		} else {
+			status = write(fd_client,
+				MSG_CMD_TOO_LONG,
+				strlen(MSG_CMD_TOO_LONG));
+			if (status == -1)
+				return status;
+
+			conn->msg_in_len = 0;
+		}
+	}
+
+	/* Write prompt */
+	status = write(fd_client,
+		conn->prompt,
+		strlen(conn->prompt));
+	if (status == -1)
+		return status;
+
+	return 0;
+}
+
+static int
+control_event_handle(struct conn *conn,
+	int fd_client)
+{
+	int status;
+
+	status = epoll_ctl(conn->fd_client_group,
+		EPOLL_CTL_DEL,
+		fd_client,
+		NULL);
+	if (status == -1)
+		return -1;
+
+	status = close(fd_client);
+	if (status == -1)
+		return -1;
+
+	return 0;
+}
+
+int
+conn_poll_for_msg(struct conn *conn)
+{
+	struct epoll_event event;
+	int fd_client, status, status_data = 0, status_control = 0;
+
+	/* Check input arguments */
+	if (conn == NULL)
+		return -1;
+
+	/* Client group */
+	status = epoll_wait(conn->fd_client_group,
+		&event,
+		1,
+		0);
+	if (status == -1)
+		return -1;
+	if (status == 0)
+		return 0;
+
+	fd_client = event.data.fd;
+
+	/* Data available */
+	if (event.events & EPOLLIN)
+		status_data = data_event_handle(conn, fd_client);
+
+	/* Control events */
+	if (event.events & (EPOLLRDHUP | EPOLLERR | EPOLLHUP))
+		status_control = control_event_handle(conn, fd_client);
+
+	if (status_data || status_control)
+		return -1;
+
+	return 0;
+}

examples/pipeline/conn.h

@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Intel Corporation
+ */
+
+#ifndef __INCLUDE_CONN_H__
+#define __INCLUDE_CONN_H__
+
+#include <stdint.h>
+
+struct conn;
+
+#ifndef CONN_WELCOME_LEN_MAX
+#define CONN_WELCOME_LEN_MAX                               1024
+#endif
+
+#ifndef CONN_PROMPT_LEN_MAX
+#define CONN_PROMPT_LEN_MAX                                16
+#endif
+
+typedef void
+(*conn_msg_handle_t)(char *msg_in,
+		     char *msg_out,
+		     size_t msg_out_len_max,
+		     void *arg);
+
+struct conn_params {
+	const char *welcome;
+	const char *prompt;
+	const char *addr;
+	uint16_t port;
+	size_t buf_size;
+	size_t msg_in_len_max;
+	size_t msg_out_len_max;
+	conn_msg_handle_t msg_handle;
+	void *msg_handle_arg;
+};
+
+struct conn *
+conn_init(struct conn_params *p);
+
+void
+conn_free(struct conn *conn);
+
+int
+conn_poll_for_conn(struct conn *conn);
+
+int
+conn_poll_for_msg(struct conn *conn);
+
+#endif

examples/pipeline/main.c

@@ -11,15 +11,136 @@
 #include <rte_launch.h>
 #include <rte_eal.h>
 
+#include "conn.h"
 #include "obj.h"
 #include "thread.h"
 
+static const char usage[] =
+	"%s EAL_ARGS -- [-h HOST] [-p PORT] [-s SCRIPT]\n";
+
+static struct app_params {
+	struct conn_params conn;
+	char *script_name;
+} app = {
+	.conn = {
+		.welcome = "\nWelcome!\n\n",
+		.prompt = "pipeline> ",
+		.addr = "0.0.0.0",
+		.port = 8086,
+		.buf_size = 1024 * 1024,
+		.msg_in_len_max = 1024,
+		.msg_out_len_max = 1024 * 1024,
+		.msg_handle = NULL,
+		.msg_handle_arg = NULL, /* set later. */
+	},
+	.script_name = NULL,
+};
+
+static int
+parse_args(int argc, char **argv)
+{
+	char *app_name = argv[0];
+	struct option lgopts[] = {
+		{ NULL,  0, 0, 0 }
+	};
+	int opt, option_index;
+	int h_present, p_present, s_present, n_args, i;
+
+	/* Skip EAL input args */
+	n_args = argc;
+	for (i = 0; i < n_args; i++)
+		if (strcmp(argv[i], "--") == 0) {
+			argc -= i;
+			argv += i;
+			break;
+		}
+
+	if (i == n_args)
+		return 0;
+
+	/* Parse args */
+	h_present = 0;
+	p_present = 0;
+	s_present = 0;
+
+	while ((opt = getopt_long(argc, argv, "h:p:s:", lgopts, &option_index))
+			!= EOF)
+		switch (opt) {
+		case 'h':
+			if (h_present) {
+				printf("Error: Multiple -h arguments\n");
+				return -1;
+			}
+			h_present = 1;
+
+			if (!strlen(optarg)) {
+				printf("Error: Argument for -h not provided\n");
+				return -1;
+			}
+
+			app.conn.addr = strdup(optarg);
+			if (app.conn.addr == NULL) {
+				printf("Error: Not enough memory\n");
+				return -1;
+			}
+			break;
+
+		case 'p':
+			if (p_present) {
+				printf("Error: Multiple -p arguments\n");
+				return -1;
+			}
+			p_present = 1;
+
+			if (!strlen(optarg)) {
+				printf("Error: Argument for -p not provided\n");
+				return -1;
+			}
+
+			app.conn.port = (uint16_t) atoi(optarg);
+			break;
+
+		case 's':
+			if (s_present) {
+				printf("Error: Multiple -s arguments\n");
+				return -1;
+			}
+			s_present = 1;
+
+			if (!strlen(optarg)) {
+				printf("Error: Argument for -s not provided\n");
+				return -1;
+			}
+
+			app.script_name = strdup(optarg);
+			if (app.script_name == NULL) {
+				printf("Error: Not enough memory\n");
+				return -1;
+			}
+			break;
+
+		default:
+			printf(usage, app_name);
+			return -1;
+		}
+
+	optind = 1; /* reset getopt lib */
+
+	return 0;
+}
+
 int
 main(int argc, char **argv)
 {
+	struct conn *conn;
 	struct obj *obj;
 	int status;
 
+	/* Parse application arguments */
+	status = parse_args(argc, argv);
+	if (status < 0)
+		return status;
+
 	/* EAL */
 	status = rte_eal_init(argc, argv);
 	if (status < 0) {
@@ -46,5 +167,19 @@ main(int argc, char **argv)
 		NULL,
 		SKIP_MASTER);
 
-	return 0;
+	/* Connectivity */
+	app.conn.msg_handle_arg = obj;
+	conn = conn_init(&app.conn);
+	if (!conn) {
+		printf("Error: Connectivity initialization failed (%d)\n",
+			status);
+		return status;
+	};
+
+	/* Dispatch loop */
+	for ( ; ; ) {
+		conn_poll_for_conn(conn);
+
+		conn_poll_for_msg(conn);
+	}
 }

examples/pipeline/meson.build

@@ -10,6 +10,7 @@ build = cc.has_header('sys/epoll.h')
 deps += ['pipeline', 'bus_pci']
 allow_experimental_apis = true
 sources = files(
+	'conn.c',
 	'main.c',
 	'obj.c',
 	'thread.c',