lib/gso/gso_common.c

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