[v3,2/3] node/kernel_rx: support receiving packets from kernel

  Adds a node to receive packets from kernel over
a raw socket.

Signed-off-by: Vamsi Attunuru <vattunuru@marvell.com>
---
 doc/guides/prog_guide/graph_lib.rst |   8 +
 lib/node/kernel_rx.c                | 276 ++++++++++++++++++++++++++++
 lib/node/kernel_rx_priv.h           |  48 +++++
 lib/node/meson.build                |   1 +
 4 files changed, 333 insertions(+)
  

Acked-by: Nithin Dabilpuram <ndabilpuram@marvell.com>

On Fri, Jun 2, 2023 at 9:52 PM Vamsi Attunuru <vattunuru@marvell.com> wrote:
>
> Adds a node to receive packets from kernel over
> a raw socket.
>
> Signed-off-by: Vamsi Attunuru <vattunuru@marvell.com>
> ---
>  doc/guides/prog_guide/graph_lib.rst |   8 +
>  lib/node/kernel_rx.c                | 276 ++++++++++++++++++++++++++++
>  lib/node/kernel_rx_priv.h           |  48 +++++
>  lib/node/meson.build                |   1 +
>  4 files changed, 333 insertions(+)
>
> diff --git a/doc/guides/prog_guide/graph_lib.rst b/doc/guides/prog_guide/graph_lib.rst
> index fa22b014f3..4b05bcee3c 100644
> --- a/doc/guides/prog_guide/graph_lib.rst
> +++ b/doc/guides/prog_guide/graph_lib.rst
> @@ -401,3 +401,11 @@ socket interface to transmit the packets, it uses the packet's destination
>  IP address in sockaddr_in address structure and ``sendto`` function to send
>  data on the raw socket. Aftering sending the burst of packets to kernel,
>  this node free up the packet buffers.
> +
> +kernel_rx
> +~~~~~~~~~
> +This node is a source node which receives packets from kernel and forwards to
> +any of the intermediate nodes. It uses the raw socket interface to receive
> +packets from kernel. 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.
> diff --git a/lib/node/kernel_rx.c b/lib/node/kernel_rx.c
> new file mode 100644
> index 0000000000..2dba7c8cc7
> --- /dev/null
> +++ b/lib/node/kernel_rx.c
> @@ -0,0 +1,276 @@
> +/* 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_rx_priv.h"
> +#include "node_private.h"
> +
> +static inline struct rte_mbuf *
> +alloc_rx_mbuf(kernel_rx_node_ctx_t *ctx)
> +{
> +       kernel_rx_info_t *rx = ctx->recv_info;
> +
> +       if (rx->idx >= rx->cnt) {
> +               uint16_t cnt;
> +
> +               rx->idx = 0;
> +               rx->cnt = 0;
> +
> +               cnt = rte_pktmbuf_alloc_bulk(ctx->pktmbuf_pool, rx->rx_bufs, KERN_RX_CACHE_COUNT);
> +               if (cnt <= 0)
> +                       return NULL;
> +
> +               rx->cnt = cnt;
> +       }
> +
> +       return rx->rx_bufs[rx->idx++];
> +}
> +
> +static inline void
> +mbuf_update(struct rte_mbuf **mbufs, uint16_t nb_pkts)
> +{
> +       struct rte_net_hdr_lens hdr_lens;
> +       struct rte_mbuf *m;
> +       int i;
> +
> +       for (i = 0; i < nb_pkts; i++) {
> +               m = mbufs[i];
> +
> +               m->packet_type = rte_net_get_ptype(m, &hdr_lens, RTE_PTYPE_ALL_MASK);
> +
> +               m->ol_flags = 0;
> +               m->tx_offload = 0;
> +
> +               m->l2_len = hdr_lens.l2_len;
> +               m->l3_len = hdr_lens.l3_len;
> +               m->l4_len = hdr_lens.l4_len;
> +       }
> +}
> +
> +static uint16_t
> +recv_pkt_parse(void **objs, uint16_t nb_pkts)
> +{
> +       uint16_t pkts_left = nb_pkts;
> +       struct rte_mbuf **pkts;
> +       int i;
> +
> +       pkts = (struct rte_mbuf **)objs;
> +
> +       if (pkts_left >= 4) {
> +               for (i = 0; i < 4; i++)
> +                       rte_prefetch0(rte_pktmbuf_mtod(pkts[i], void *));
> +       }
> +
> +       while (pkts_left >= 12) {
> +               /* Prefetch next-next mbufs */
> +               rte_prefetch0(pkts[8]);
> +               rte_prefetch0(pkts[9]);
> +               rte_prefetch0(pkts[10]);
> +               rte_prefetch0(pkts[11]);
> +
> +               /* Prefetch next mbuf data */
> +               rte_prefetch0(rte_pktmbuf_mtod(pkts[4], void *));
> +               rte_prefetch0(rte_pktmbuf_mtod(pkts[5], void *));
> +               rte_prefetch0(rte_pktmbuf_mtod(pkts[6], void *));
> +               rte_prefetch0(rte_pktmbuf_mtod(pkts[7], void *));
> +
> +               /* Extract ptype of mbufs */
> +               mbuf_update(pkts, 4);
> +
> +               pkts += 4;
> +               pkts_left -= 4;
> +       }
> +
> +       if (pkts_left > 0)
> +               mbuf_update(pkts, pkts_left);
> +
> +       return nb_pkts;
> +}
> +
> +static uint16_t
> +kernel_rx_node_do(struct rte_graph *graph, struct rte_node *node, kernel_rx_node_ctx_t *ctx)
> +{
> +       kernel_rx_info_t *rx;
> +       uint16_t next_index;
> +       int fd;
> +
> +       rx = ctx->recv_info;
> +       next_index = rx->node_next;
> +
> +       fd = rx->sock;
> +       if (fd > 0) {
> +               struct rte_mbuf **mbufs;
> +               uint16_t len = 0, count = 0;
> +               int nb_cnt, i;
> +
> +               nb_cnt = (node->size >= RTE_GRAPH_BURST_SIZE) ? RTE_GRAPH_BURST_SIZE : node->size;
> +
> +               mbufs = (struct rte_mbuf **)node->objs;
> +               for (i = 0; i < nb_cnt; i++) {
> +                       struct rte_mbuf *m = alloc_rx_mbuf(ctx);
> +
> +                       if (!m)
> +                               break;
> +
> +                       len = read(fd, rte_pktmbuf_mtod(m, char *), rte_pktmbuf_tailroom(m));
> +                       if (len == 0 || len == 0xFFFF) {
> +                               rte_pktmbuf_free(m);
> +                               if (rx->idx <= 0)
> +                                       node_dbg("kernel_rx", "rx_mbuf array is empty\n");
> +                               rx->idx--;
> +                               break;
> +                       }
> +                       *mbufs++ = m;
> +
> +                       m->port = node->id;
> +                       rte_pktmbuf_data_len(m) = len;
> +
> +                       count++;
> +               }
> +
> +               if (count) {
> +                       recv_pkt_parse(node->objs, count);
> +                       node->idx = count;
> +
> +                       /* Enqueue to next node */
> +                       rte_node_next_stream_move(graph, node, next_index);
> +               }
> +
> +               return count;
> +       }
> +
> +       return 0;
> +}
> +
> +static uint16_t
> +kernel_rx_node_process(struct rte_graph *graph, struct rte_node *node, void **objs,
> +                        uint16_t nb_objs)
> +{
> +       kernel_rx_node_ctx_t *ctx = (kernel_rx_node_ctx_t *)node->ctx;
> +       int fd;
> +
> +       RTE_SET_USED(objs);
> +       RTE_SET_USED(nb_objs);
> +
> +       if (!ctx)
> +               return 0;
> +
> +       fd = ctx->recv_info->sock;
> +       if (fd > 0) {
> +               struct pollfd fds = {.fd = fd, .events = POLLIN};
> +
> +               if (poll(&fds, 1, 0) > 0) {
> +                       if (fds.revents & POLLIN)
> +                               return kernel_rx_node_do(graph, node, ctx);
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +static int
> +kernel_rx_node_init(const struct rte_graph *graph, struct rte_node *node)
> +{
> +       struct kernel_rx_node_main *rx_node_main = kernel_rx_node_data_get();
> +       kernel_rx_node_ctx_t *ctx = (kernel_rx_node_ctx_t *)node->ctx;
> +       kernel_rx_node_elem_t *elem = rx_node_main->head;
> +       kernel_rx_info_t *recv_info;
> +       int sock;
> +
> +       while (elem) {
> +               if (elem->nid == node->id) {
> +                       /* Update node specific context */
> +                       memcpy(ctx, &elem->ctx, sizeof(kernel_rx_node_ctx_t));
> +                       break;
> +               }
> +               elem = elem->next;
> +       }
> +
> +       RTE_VERIFY(elem != NULL);
> +
> +       if (ctx->pktmbuf_pool == NULL) {
> +               node_err("kernel_rx", "Invalid mbuf pool on graph %s\n", graph->name);
> +               return -EINVAL;
> +       }
> +
> +       recv_info = rte_zmalloc_socket("kernel_rx_info", sizeof(kernel_rx_info_t),
> +                                      RTE_CACHE_LINE_SIZE, graph->socket);
> +       if (!recv_info) {
> +               node_err("kernel_rx", "Kernel recv_info is NULL\n");
> +               return -ENOMEM;
> +       }
> +
> +       sock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
> +       if (sock < 0) {
> +               node_err("kernel_rx", "Unable to open RAW socket\n");
> +               return sock;
> +       }
> +
> +       recv_info->sock = sock;
> +       ctx->recv_info = recv_info;
> +
> +       return 0;
> +}
> +
> +static void
> +kernel_rx_node_fini(const struct rte_graph *graph __rte_unused, struct rte_node *node)
> +{
> +       kernel_rx_node_ctx_t *ctx = (kernel_rx_node_ctx_t *)node->ctx;
> +
> +       if (ctx->recv_info) {
> +               close(ctx->recv_info->sock);
> +               ctx->recv_info->sock = -1;
> +               rte_free(ctx->recv_info);
> +       }
> +
> +       ctx->recv_info = NULL;
> +}
> +
> +struct kernel_rx_node_main *
> +kernel_rx_node_data_get(void)
> +{
> +       static struct kernel_rx_node_main kernel_rx_main;
> +
> +       return &kernel_rx_main;
> +}
> +
> +static struct rte_node_register kernel_rx_node_base = {
> +       .process = kernel_rx_node_process,
> +       .flags = RTE_NODE_SOURCE_F,
> +       .name = "kernel_rx",
> +
> +       .init = kernel_rx_node_init,
> +       .fini = kernel_rx_node_fini,
> +
> +       .nb_edges = KERNEL_RX_NEXT_MAX,
> +       .next_nodes = {
> +                       [KERNEL_RX_NEXT_PKT_CLS] = "pkt_cls",
> +                       [KERNEL_RX_NEXT_IP4_LOOKUP] = "ip4_lookup",
> +       },
> +};
> +
> +struct rte_node_register *
> +kernel_rx_node_get(void)
> +{
> +       return &kernel_rx_node_base;
> +}
> +
> +RTE_NODE_REGISTER(kernel_rx_node_base);
> diff --git a/lib/node/kernel_rx_priv.h b/lib/node/kernel_rx_priv.h
> new file mode 100644
> index 0000000000..f1aa2344d7
> --- /dev/null
> +++ b/lib/node/kernel_rx_priv.h
> @@ -0,0 +1,48 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(C) 2023 Marvell International Ltd.
> + */
> +
> +#ifndef __KERNEL_RX_PRIV_H__
> +#define __KERNEL_RX_PRIV_H__
> +
> +#define KERN_RX_CACHE_COUNT 64
> +
> +typedef struct kernel_rx_info {
> +       struct rte_mbuf *rx_bufs[KERN_RX_CACHE_COUNT];
> +       uint16_t node_next;
> +       uint16_t idx;
> +       uint16_t cnt;
> +       int sock;
> +} kernel_rx_info_t;
> +
> +/* kernel_rx node context structure */
> +typedef struct kernel_rx_node_ctx {
> +       struct rte_mempool *pktmbuf_pool;
> +       kernel_rx_info_t *recv_info;
> +} kernel_rx_node_ctx_t;
> +
> +/* kernel_rx node list element structure */
> +typedef struct kernel_rx_node_elem {
> +       struct kernel_rx_node_elem *next; /* Pointer to the next node element. */
> +       struct kernel_rx_node_ctx ctx;    /* kernel_rx node context. */
> +       rte_node_t nid;                   /* Node identifier of the kernel_rx node. */
> +} kernel_rx_node_elem_t;
> +
> +enum kernel_rx_next_nodes {
> +       KERNEL_RX_NEXT_PKT_CLS,
> +       KERNEL_RX_NEXT_IP4_LOOKUP,
> +       KERNEL_RX_NEXT_MAX,
> +};
> +
> +/* kernel_rx node main structure */
> +struct kernel_rx_node_main {
> +       kernel_rx_node_elem_t *head; /* Pointer to the head node element. */
> +};
> +
> +/* Get the pointer of kernel_rx node data */
> +struct kernel_rx_node_main *kernel_rx_node_data_get(void);
> +
> +/* Get the pointer of kernel_rx node register structure */
> +struct rte_node_register *kernel_rx_node_get(void);
> +
> +#endif /* __KERNEL_RX_PRIV_H__ */
> diff --git a/lib/node/meson.build b/lib/node/meson.build
> index 0520be23ff..1f04fd1d7e 100644
> --- a/lib/node/meson.build
> +++ b/lib/node/meson.build
> @@ -13,6 +13,7 @@ sources = files(
>          'ethdev_tx.c',
>          'ip4_lookup.c',
>          'ip4_rewrite.c',
> +        'kernel_rx.c',
>          'kernel_tx.c',
>          'log.c',
>          'null.c',
> --
> 2.25.1
>