LXR dpdk/lib/gso/gso

   1/* SPDX-License-Identifier: BSD-3-Clause
   2 * Copyright(c) 2017 Intel Corporation
   3 */
   4
   5#include <stdbool.h>
   6#include <errno.h>
   7
   8#include <rte_memcpy.h>
   9#include <rte_mempool.h>
  10
  11#include "gso_common.h"
  12
  13static inline void
  14hdr_segment_init(struct rte_mbuf *hdr_segment, struct rte_mbuf *pkt,
  15                uint16_t pkt_hdr_offset)
  16{
  17        /* Copy MBUF metadata */
  18        hdr_segment->nb_segs = 1;
  19        hdr_segment->port = pkt->port;
  20        hdr_segment->ol_flags = pkt->ol_flags;
  21        hdr_segment->packet_type = pkt->packet_type;
  22        hdr_segment->pkt_len = pkt_hdr_offset;
  23        hdr_segment->data_len = pkt_hdr_offset;
  24        hdr_segment->tx_offload = pkt->tx_offload;
  25
  26        /* Copy the packet header */
  27        rte_memcpy(rte_pktmbuf_mtod(hdr_segment, char *),
  28                        rte_pktmbuf_mtod(pkt, char *),
  29                        pkt_hdr_offset);
  30}
  31
  32static inline void
  33free_gso_segment(struct rte_mbuf **pkts, uint16_t nb_pkts)
  34{
  35        uint16_t i;
  36
  37        for (i = 0; i < nb_pkts; i++)
  38                rte_pktmbuf_free(pkts[i]);
  39}
  40
  41int
  42gso_do_segment(struct rte_mbuf *pkt,
  43                uint16_t pkt_hdr_offset,
  44                uint16_t pyld_unit_size,
  45                struct rte_mempool *direct_pool,
  46                struct rte_mempool *indirect_pool,
  47                struct rte_mbuf **pkts_out,
  48                uint16_t nb_pkts_out)
  49{
  50        struct rte_mbuf *pkt_in;
  51        struct rte_mbuf *hdr_segment, *pyld_segment, *prev_segment;
  52        uint16_t pkt_in_data_pos, segment_bytes_remaining;
  53        uint16_t pyld_len, nb_segs;
  54        bool more_in_pkt, more_out_segs;
  55
  56        pkt_in = pkt;
  57        nb_segs = 0;
  58        more_in_pkt = 1;
  59        pkt_in_data_pos = pkt_hdr_offset;
  60
  61        while (more_in_pkt) {
  62                if (unlikely(nb_segs >= nb_pkts_out)) {
  63                        free_gso_segment(pkts_out, nb_segs);
  64                        return -EINVAL;
  65                }
  66
  67                /* Allocate a direct MBUF */
  68                hdr_segment = rte_pktmbuf_alloc(direct_pool);
  69                if (unlikely(hdr_segment == NULL)) {
  70                        free_gso_segment(pkts_out, nb_segs);
  71                        return -ENOMEM;
  72                }
  73                /* Fill the packet header */
  74                hdr_segment_init(hdr_segment, pkt, pkt_hdr_offset);
  75
  76                prev_segment = hdr_segment;
  77                segment_bytes_remaining = pyld_unit_size;
  78                more_out_segs = 1;
  79
  80                while (more_out_segs && more_in_pkt) {
  81                        /* Allocate an indirect MBUF */
  82                        pyld_segment = rte_pktmbuf_alloc(indirect_pool);
  83                        if (unlikely(pyld_segment == NULL)) {
  84                                rte_pktmbuf_free(hdr_segment);
  85                                free_gso_segment(pkts_out, nb_segs);
  86                                return -ENOMEM;
  87                        }
  88                        /* Attach to current MBUF segment of pkt */
  89                        rte_pktmbuf_attach(pyld_segment, pkt_in);
  90
  91                        prev_segment->next = pyld_segment;
  92                        prev_segment = pyld_segment;
  93
  94                        pyld_len = segment_bytes_remaining;
  95                        if (pyld_len + pkt_in_data_pos > pkt_in->data_len)
  96                                pyld_len = pkt_in->data_len - pkt_in_data_pos;
  97
  98                        pyld_segment->data_off = pkt_in_data_pos +
  99                                pkt_in->data_off;
 100                        pyld_segment->data_len = pyld_len;
 101
 102                        /* Update header segment */
 103                        hdr_segment->pkt_len += pyld_len;
 104                        hdr_segment->nb_segs++;
 105
 106                        pkt_in_data_pos += pyld_len;
 107                        segment_bytes_remaining -= pyld_len;
 108
 109                        /* Finish processing a MBUF segment of pkt */
 110                        if (pkt_in_data_pos == pkt_in->data_len) {
 111                                pkt_in = pkt_in->next;
 112                                pkt_in_data_pos = 0;
 113                                if (pkt_in == NULL)
 114                                        more_in_pkt = 0;
 115                        }
 116
 117                        /* Finish generating a GSO segment */
 118                        if (segment_bytes_remaining == 0)
 119                                more_out_segs = 0;
 120                }
 121                pkts_out[nb_segs++] = hdr_segment;
 122        }
 123        return nb_segs;
 124}
 125