Re: [dpdk-dev] [PATCH 4/5] net/mlx5: add socket server for external tools

[Slava Ovsiienko <viacheslavo@mellanox.com>]

Hi, Jack

> -----Original Message-----
> From: Xiaoyu Min <jackmin@mellanox.com>
> Sent: Thursday, January 16, 2020 12:14
> To: jerinjacobk@gmail.com; Ori Kam <orika@mellanox.com>; Slava Ovsiienko
> <viacheslavo@mellanox.com>; Matan Azrad <matan@mellanox.com>; Raslan
> Darawsheh <rasland@mellanox.com>; Shahaf Shuler
> <shahafs@mellanox.com>; Anatoly Burakov <anatoly.burakov@intel.com>
> Cc: dev@dpdk.org; Xueming(Steven) Li <xuemingl@mellanox.com>
> Subject: [PATCH 4/5] net/mlx5: add socket server for external tools
> 
> 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 | 227 +++++++++++++++++++++++++++++++++
>  5 files changed, 236 insertions(+)
>  create mode 100644 drivers/net/mlx5/mlx5_socket.c
> 
> diff --git a/drivers/net/mlx5/Makefile b/drivers/net/mlx5/Makefile index
> 6e5921b292..397e29dcbb 100644
> --- a/drivers/net/mlx5/Makefile
> +++ b/drivers/net/mlx5/Makefile
> @@ -39,6 +39,7 @@ SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_mp.c
>  SRCS-$(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-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_socket.c
> 
>  ifeq ($(CONFIG_RTE_IBVERBS_LINK_DLOPEN),y)
>  INSTALL-$(CONFIG_RTE_LIBRTE_MLX5_PMD)-lib += $(LIB_GLUE) diff --git
> a/drivers/net/mlx5/meson.build b/drivers/net/mlx5/meson.build index
> d7ef032afb..cb2fb90495 100644
> --- a/drivers/net/mlx5/meson.build
> +++ b/drivers/net/mlx5/meson.build
> @@ -61,6 +61,7 @@ if build
>  		'mlx5_vlan.c',
>  		'mlx5_devx_cmds.c',
>  		'mlx5_utils.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
> 047181b32e..ceb6de821e 100644
> --- a/drivers/net/mlx5/mlx5.h
> +++ b/drivers/net/mlx5/mlx5.h
> @@ -990,6 +990,11 @@ 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..e4c93c4312
> --- /dev/null
> +++ b/drivers/net/mlx5/mlx5_socket.c
> @@ -0,0 +1,227 @@
> +/* 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 "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;
> +	struct rte_eth_dev *dev;
> +
> +	/* 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));
I would add the port_id check here.
The message with wrong port_id may crash the server.


> +	/* Dump flow. */
> +	dev = &rte_eth_devices[port_id];
> +	ret = mlx5_flow_dev_dump(dev, file, NULL);
> +	/* 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());
I would move the MKSTR a couple lines below, after the close() call.

> +	claim_zero(close(server_socket));
> +	server_socket = 0;
> +	claim_zero(remove(path));
> +}
> --
> 2.24.1
With best regards, Slava