[PATCH 2/4] node: add a node to receive pkts from kernel

[Jerin Jacob]

On Fri, Apr 21, 2023 at 11:33 AM Vamsi Attunuru <vattunuru at marvell.com> wrote:
>
> Patch adds a node to receive packets from kernel
> over a raw socket.

Subjection suggestion: node/kernel_rx: support receving packet from kernel
>
> Signed-off-by: Vamsi Attunuru <vattunuru at marvell.com>
> ---
>  doc/guides/prog_guide/graph_lib.rst |   7 +
>  lib/node/kernel_recv.c              | 277 ++++++++++++++++++++++++++++
>  lib/node/kernel_recv_priv.h         |  74 ++++++++
>  lib/node/meson.build                |   1 +
>  4 files changed, 359 insertions(+)
>
> diff --git a/doc/guides/prog_guide/graph_lib.rst b/doc/guides/prog_guide/graph_lib.rst
> index b3b5b14827..1057f16de8 100644
> --- a/doc/guides/prog_guide/graph_lib.rst
> +++ b/doc/guides/prog_guide/graph_lib.rst
> @@ -402,3 +402,10 @@ on the raw socket.
>
>  Aftering sending the burst of packets to kernel, this node redirects the same
>  objects to pkt_drop node to free up the packet buffers.
> +
> +kernel_recv

Better to change node name to kernel_rx

> +~~~~~~~~~~~
> +This node receives packets from kernel over a raw socket interface. Uses ``poll``
> +function to poll on the socket fd for ``POLLIN`` events to read the packets from
> +raw socket to stream buffer and does ``rte_node_next_stream_move()`` when there
> +are received packets.

You can tell typical use case for punt and kernel_tx node. i.e
expection path handling.
Also, may consider chnage to kernel_tx  for punt node.


> diff --git a/lib/node/kernel_recv.c b/lib/node/kernel_recv.c
> new file mode 100644
> index 0000000000..361dcc3b5f
> --- /dev/null
> +++ b/lib/node/kernel_recv.c
> @@ -0,0 +1,277 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(C) 2023 Marvell International Ltd.
> + */
> +
> +#include <fcntl.h>
> +#include <poll.h>
> +#include <stdlib.h>
> +#include <sys/ioctl.h>
> +#include <sys/socket.h>
> +#include <unistd.h>
> +
> +#include <rte_debug.h>
> +#include <rte_ethdev.h>
> +#include <rte_graph.h>
> +#include <rte_graph_worker.h>
> +#include <rte_ip.h>
> +#include <rte_malloc.h>
> +#include <rte_mbuf.h>
> +#include <rte_mempool.h>
> +#include <rte_net.h>
> +
> +#include "ethdev_rx_priv.h"
> +#include "kernel_recv_priv.h"
> +#include "node_private.h"
> +
> +static struct kernel_recv_node_main kernel_recv_main;

Try to remove global varible.

> +#ifndef __INCLUDE_KERNEL_RECV_PRIV_H__

No need to add INCLUDE

> +#define __INCLUDE_KERNEL_RECV_PRIV_H__
> +
> +#define KERN_RECV_CACHE_COUNT 64
> +
> +typedef struct kernel_recv_info {
> +       struct rte_mbuf *rx_bufs[KERN_RECV_CACHE_COUNT];
> +       uint16_t cls_next;
> +       uint16_t idx;
> +       uint16_t cnt;
> +       int sock;
> +} kernel_recv_info_t;
> +
> +/**
> + * @internal
> + *
> + * Kernel Recv node context structure.

Across the patch series, no need for Doxgen comments for internal functions.