[dpdk-dev] [RFC 3/4] net/mlx5: add socket server for external tools

[Xiaoyu Min <jackmin@mellanox.com>]

From: Xueming Li <xuemingl@mellanox.com>

Add pmd unix socket server to enable external tool applications to
trigger flow dump.

Socket path:
	/var/tmp/dpdk_mlx5_<pid>
Socket format:
	io_raw: port_id of uint16
	file: file descriptor of int

Signed-off-by: Xueming Li <xuemingl@mellanox.com>
Signed-off-by: Xiaoyu Min <jackmin@mellanox.com>
---
 drivers/net/mlx5/Makefile      |   1 +
 drivers/net/mlx5/meson.build   |   1 +
 drivers/net/mlx5/mlx5.c        |   2 +
 drivers/net/mlx5/mlx5.h        |   5 +
 drivers/net/mlx5/mlx5_socket.c | 226 +++++++++++++++++++++++++++++++++
 5 files changed, 235 insertions(+)
 create mode 100644 drivers/net/mlx5/mlx5_socket.c

diff --git a/drivers/net/mlx5/Makefile b/drivers/net/mlx5/Makefile
index 0ff907445e..5f64d6ef02 100644
--- a/drivers/net/mlx5/Makefile
+++ b/drivers/net/mlx5/Makefile
@@ -40,6 +40,7 @@ SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_nl.c
 SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_devx_cmds.c
 SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_utils.c
 SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += rte_pmd_mlx5.c
+SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_socket.c
 
 # Export include files of private API.
 SYMLINK-$(CONFIG_RTE_LIBRTE_MLX5_PMD)-include += rte_pmd_mlx5.h
diff --git a/drivers/net/mlx5/meson.build b/drivers/net/mlx5/meson.build
index 1bdebcb6fc..8e5aabfdd3 100644
--- a/drivers/net/mlx5/meson.build
+++ b/drivers/net/mlx5/meson.build
@@ -62,6 +62,7 @@ if build
 		'mlx5_devx_cmds.c',
 		'mlx5_utils.c',
 		'rte_pmd_mlx5.c',
+		'mlx5_socket.c',
 	)
 	if (dpdk_conf.has('RTE_ARCH_X86_64')
 		or dpdk_conf.has('RTE_ARCH_ARM64')
diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index 50960c91ce..ffee39c1a0 100644
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -2954,6 +2954,8 @@ mlx5_pci_probe(struct rte_pci_driver *pci_drv __rte_unused,
 	struct mlx5_dev_config dev_config;
 	int ret;
 
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+		mlx5_pmd_socket_init();
 	ret = mlx5_init_once();
 	if (ret) {
 		DRV_LOG(ERR, "unable to init PMD global data: %s",
diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
index 68b08a7f0b..92713551aa 100644
--- a/drivers/net/mlx5/mlx5.h
+++ b/drivers/net/mlx5/mlx5.h
@@ -988,6 +988,11 @@ void mlx5_mp_uninit_primary(void);
 int mlx5_mp_init_secondary(void);
 void mlx5_mp_uninit_secondary(void);
 
+/* mlx5_socket.c */
+
+int mlx5_pmd_socket_init(void);
+void mlx5_pmd_socket_uninit(void);
+
 /* mlx5_nl.c */
 
 int mlx5_nl_init(int protocol);
diff --git a/drivers/net/mlx5/mlx5_socket.c b/drivers/net/mlx5/mlx5_socket.c
new file mode 100644
index 0000000000..afd0ec9ac2
--- /dev/null
+++ b/drivers/net/mlx5/mlx5_socket.c
@@ -0,0 +1,226 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2019 Mellanox Technologies, Ltd
+ */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+#include "rte_eal.h"
+#include "mlx5_utils.h"
+#include "rte_pmd_mlx5.h"
+#include "mlx5.h"
+
+/* PMD socket service for tools. */
+
+int server_socket; /* Unix socket for primary process. */
+struct rte_intr_handle server_intr_handle; /* Interrupt handler. */
+
+static void
+mlx5_pmd_make_path(struct sockaddr_un *addr, int pid)
+{
+	snprintf(addr->sun_path, sizeof(addr->sun_path), "/var/tmp/dpdk_%s_%d",
+		 MLX5_DRIVER_NAME, pid);
+}
+
+/**
+ * Handle server pmd socket interrupts.
+ */
+static void
+mlx5_pmd_socket_handle(void *cb __rte_unused)
+{
+	int conn_sock;
+	int ret = -1;
+	struct cmsghdr *cmsg = NULL;
+	int data;
+	char buf[CMSG_SPACE(sizeof(int))] = { 0 };
+	struct iovec io = {
+		.iov_base = &data,
+		.iov_len = sizeof(data),
+	};
+	struct msghdr msg = {
+		.msg_iov = &io,
+		.msg_iovlen = 1,
+		.msg_control = buf,
+		.msg_controllen = sizeof(buf),
+	};
+	uint16_t port_id;
+	int fd;
+	FILE *file = NULL;
+
+	/* Accept the connection from the client. */
+	conn_sock = accept(server_socket, NULL, NULL);
+	if (conn_sock < 0) {
+		DRV_LOG(WARNING, "connection failed: %s", strerror(errno));
+		return;
+	}
+	ret = recvmsg(conn_sock, &msg, MSG_WAITALL);
+	if (ret < 0) {
+		DRV_LOG(WARNING, "wrong message received: %s",
+			strerror(errno));
+		goto error;
+	}
+	/* Receive file descriptor. */
+	cmsg = CMSG_FIRSTHDR(&msg);
+	if (cmsg == NULL || cmsg->cmsg_type != SCM_RIGHTS ||
+	    cmsg->cmsg_len < sizeof(int)) {
+		DRV_LOG(WARNING, "invalid file descriptor message");
+		goto error;
+	}
+	memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd));
+	file = fdopen(fd, "w");
+	if (!file) {
+		DRV_LOG(WARNING, "Failed to open file");
+		goto error;
+	}
+	/* Receive port number. */
+	if (msg.msg_iovlen != 1 || msg.msg_iov->iov_len < sizeof(uint16_t)) {
+		DRV_LOG(WARNING, "wrong port number message");
+		goto error;
+	}
+	memcpy(&port_id, msg.msg_iov->iov_base, sizeof(port_id));
+	/* Dump flow. */
+	ret = rte_pmd_mlx5_flow_dump(port_id, file);
+	/* Set-up the ancillary data and reply. */
+	msg.msg_controllen = 0;
+	msg.msg_control = NULL;
+	msg.msg_iovlen = 1;
+	msg.msg_iov = &io;
+	data = -ret;
+	io.iov_len = sizeof(data);
+	io.iov_base = &data;
+	do {
+		ret = sendmsg(conn_sock, &msg, 0);
+	} while (ret < 0 && errno == EINTR);
+	if (ret < 0)
+		DRV_LOG(WARNING, "failed to send response %s",
+			strerror(errno));
+error:
+	if (conn_sock > 0)
+		close(conn_sock);
+	if (file)
+		fclose(file);
+}
+
+/**
+ * Install interrupt handler.
+ *
+ * @param dev
+ *   Pointer to Ethernet device.
+ * @return
+ *   0 on success, a negative errno value otherwise.
+ */
+static int
+mlx5_pmd_interrupt_handler_install(void)
+{
+	assert(server_socket);
+	server_intr_handle.fd = server_socket;
+	server_intr_handle.type = RTE_INTR_HANDLE_EXT;
+	return rte_intr_callback_register(&server_intr_handle,
+					  mlx5_pmd_socket_handle, NULL);
+}
+
+/**
+ * Uninstall interrupt handler.
+ */
+static void
+mlx5_pmd_interrupt_handler_uninstall(void)
+{
+	if (server_socket) {
+		mlx5_intr_callback_unregister(&server_intr_handle,
+					      mlx5_pmd_socket_handle,
+					      NULL);
+	}
+	server_intr_handle.fd = 0;
+	server_intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
+}
+
+/**
+ * Initialise the socket to communicate with the secondary process
+ *
+ * @param[in] dev
+ *   Pointer to Ethernet device.
+ *
+ * @return
+ *   0 on success, a negative value otherwise.
+ */
+int
+mlx5_pmd_socket_init(void)
+{
+	struct sockaddr_un sun = {
+		.sun_family = AF_UNIX,
+	};
+	int ret = -1;
+	int flags;
+
+	assert(rte_eal_process_type() == RTE_PROC_PRIMARY);
+	if (server_socket)
+		return 0;
+	/*
+	 * Initialize the socket to communicate with the secondary
+	 * process.
+	 */
+	ret = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (ret < 0) {
+		DRV_LOG(WARNING, "Failed to open mlx5 socket: %s",
+			strerror(errno));
+		goto error;
+	}
+	server_socket = ret;
+	flags = fcntl(server_socket, F_GETFL, 0);
+	if (flags == -1)
+		goto error;
+	ret = fcntl(server_socket, F_SETFL, flags | O_NONBLOCK);
+	if (ret < 0)
+		goto error;
+	mlx5_pmd_make_path(&sun, getpid());
+	remove(sun.sun_path);
+	ret = bind(server_socket, (const struct sockaddr *)&sun, sizeof(sun));
+	if (ret < 0) {
+		DRV_LOG(WARNING,
+			"cannot bind mlx5 socket: %s", strerror(errno));
+		goto close;
+	}
+	ret = listen(server_socket, 0);
+	if (ret < 0) {
+		DRV_LOG(WARNING, "cannot listen on mlx5 socket: %s",
+			strerror(errno));
+		goto close;
+	}
+	if (mlx5_pmd_interrupt_handler_install()) {
+		DRV_LOG(WARNING, "cannot register interrupt handler for mlx5 socket: %s",
+			strerror(errno));
+		goto close;
+	}
+	return 0;
+close:
+	remove(sun.sun_path);
+error:
+	claim_zero(close(server_socket));
+	server_socket = 0;
+	DRV_LOG(ERR, "Cannot initialize socket: %s", strerror(errno));
+	return -errno;
+}
+
+/**
+ * Un-Initialize the pmd socket
+ */
+void __attribute__((destructor))
+mlx5_pmd_socket_uninit(void)
+{
+	if (!server_socket)
+		return;
+	mlx5_pmd_interrupt_handler_uninstall();
+	MKSTR(path, "/var/tmp/dpdk_%s_%d", MLX5_DRIVER_NAME, getpid());
+	claim_zero(close(server_socket));
+	server_socket = 0;
+	claim_zero(remove(path));
+}
-- 
2.24.1