lib/gso/gso_tunnel_udp4.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2020 Inspur Corporation
   3  */
   4
   5 #include "gso_common.h"
   6 #include "gso_tunnel_udp4.h"
   7
   8 #define IPV4_HDR_MF_BIT (1U << 13)
   9
  10 static void
  11 update_tunnel_ipv4_udp_headers(struct rte_mbuf *pkt, struct rte_mbuf **segs,
  12                                uint16_t nb_segs)
  13 {
  14         struct rte_ipv4_hdr *ipv4_hdr;
  15         uint16_t outer_id, inner_id, tail_idx, i, length;
  16         uint16_t outer_ipv4_offset, inner_ipv4_offset;
  17         uint16_t outer_udp_offset;
  18         uint16_t frag_offset = 0, is_mf;
  19
  20         outer_ipv4_offset = pkt->outer_l2_len;
  21         outer_udp_offset = outer_ipv4_offset + pkt->outer_l3_len;
  22         inner_ipv4_offset = outer_udp_offset + pkt->l2_len;
  23
  24         /* Outer IPv4 header. */
  25         ipv4_hdr = (struct rte_ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
  26                         outer_ipv4_offset);
  27         outer_id = rte_be_to_cpu_16(ipv4_hdr->packet_id);
  28
  29         /* Inner IPv4 header. */
  30         ipv4_hdr = (struct rte_ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
  31                         inner_ipv4_offset);
  32         inner_id = rte_be_to_cpu_16(ipv4_hdr->packet_id);
  33
  34         tail_idx = nb_segs - 1;
  35
  36         for (i = 0; i < nb_segs; i++) {
  37                 update_ipv4_header(segs[i], outer_ipv4_offset, outer_id);
  38                 update_udp_header(segs[i], outer_udp_offset);
  39                 update_ipv4_header(segs[i], inner_ipv4_offset, inner_id);
  40                 /* For the case inner packet is UDP, we must keep UDP
  41                  * datagram boundary, it must be handled as IP fragment.
  42                  *
  43                  * Set IP fragment offset for inner IP header.
  44                  */
  45                 ipv4_hdr = (struct rte_ipv4_hdr *)
  46                         (rte_pktmbuf_mtod(segs[i], char *) +
  47                                 inner_ipv4_offset);
  48                 is_mf = i < tail_idx ? IPV4_HDR_MF_BIT : 0;
  49                 ipv4_hdr->fragment_offset =
  50                         rte_cpu_to_be_16(frag_offset | is_mf);
  51                 length = segs[i]->pkt_len - inner_ipv4_offset - pkt->l3_len;
  52                 frag_offset += (length >> 3);
  53                 outer_id++;
  54         }
  55 }
  56
  57 int
  58 gso_tunnel_udp4_segment(struct rte_mbuf *pkt,
  59                 uint16_t gso_size,
  60                 struct rte_mempool *direct_pool,
  61                 struct rte_mempool *indirect_pool,
  62                 struct rte_mbuf **pkts_out,
  63                 uint16_t nb_pkts_out)
  64 {
  65         struct rte_ipv4_hdr *inner_ipv4_hdr;
  66         uint16_t pyld_unit_size, hdr_offset, frag_off;
  67         int ret;
  68
  69         hdr_offset = pkt->outer_l2_len + pkt->outer_l3_len + pkt->l2_len;
  70         inner_ipv4_hdr = (struct rte_ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
  71                         hdr_offset);
  72         /*
  73          * Don't process the packet whose MF bit or offset in the inner
  74          * IPv4 header are non-zero.
  75          */
  76         frag_off = rte_be_to_cpu_16(inner_ipv4_hdr->fragment_offset);
  77         if (unlikely(IS_FRAGMENTED(frag_off)))
  78                 return 0;
  79
  80         hdr_offset += pkt->l3_len;
  81         /* Don't process the packet without data */
  82         if ((hdr_offset + pkt->l4_len) >= pkt->pkt_len)
  83                 return 0;
  84
  85         /* pyld_unit_size must be a multiple of 8 because frag_off
  86          * uses 8 bytes as unit.
  87          */
  88         pyld_unit_size = (gso_size - hdr_offset) & ~7U;
  89
  90         /* Segment the payload */
  91         ret = gso_do_segment(pkt, hdr_offset, pyld_unit_size, direct_pool,
  92                         indirect_pool, pkts_out, nb_pkts_out);
  93         if (ret > 1)
  94                 update_tunnel_ipv4_udp_headers(pkt, pkts_out, ret);
  95
  96         return ret;
  97 }