ceph/src/seastar/dpdk/lib/librte_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 #include <rte_mempool.h>
  10
  11 #include "gso_common.h"
  12
  13 static inline void
  14 hdr_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
  32 static inline void
  33 free_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
  41 int
  42 gso_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 }