ceph/src/spdk/dpdk/lib/librte_ip_frag/rte_ipv6_fragmentation.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2014 Intel Corporation
   3  */
   4
   5 #include <stddef.h>
   6 #include <errno.h>
   7
   8 #include <rte_memcpy.h>
   9
  10 #include "ip_frag_common.h"
  11
  12 /**
  13  * @file
  14  * RTE IPv6 Fragmentation
  15  *
  16  * Implementation of IPv6 fragmentation.
  17  *
  18  */
  19
  20 static inline void
  21 __fill_ipv6hdr_frag(struct ipv6_hdr *dst,
  22                 const struct ipv6_hdr *src, uint16_t len, uint16_t fofs,
  23                 uint32_t mf)
  24 {
  25         struct ipv6_extension_fragment *fh;
  26
  27         rte_memcpy(dst, src, sizeof(*dst));
  28         dst->payload_len = rte_cpu_to_be_16(len);
  29         dst->proto = IPPROTO_FRAGMENT;
  30
  31         fh = (struct ipv6_extension_fragment *) ++dst;
  32         fh->next_header = src->proto;
  33         fh->reserved = 0;
  34         fh->frag_data = rte_cpu_to_be_16(RTE_IPV6_SET_FRAG_DATA(fofs, mf));
  35         fh->id = 0;
  36 }
  37
  38 static inline void
  39 __free_fragments(struct rte_mbuf *mb[], uint32_t num)
  40 {
  41         uint32_t i;
  42         for (i = 0; i < num; i++)
  43                 rte_pktmbuf_free(mb[i]);
  44 }
  45
  46 /**
  47  * IPv6 fragmentation.
  48  *
  49  * This function implements the fragmentation of IPv6 packets.
  50  *
  51  * @param pkt_in
  52  *   The input packet.
  53  * @param pkts_out
  54  *   Array storing the output fragments.
  55  * @param mtu_size
  56  *   Size in bytes of the Maximum Transfer Unit (MTU) for the outgoing IPv6
  57  *   datagrams. This value includes the size of the IPv6 header.
  58  * @param pool_direct
  59  *   MBUF pool used for allocating direct buffers for the output fragments.
  60  * @param pool_indirect
  61  *   MBUF pool used for allocating indirect buffers for the output fragments.
  62  * @return
  63  *   Upon successful completion - number of output fragments placed
  64  *   in the pkts_out array.
  65  *   Otherwise - (-1) * <errno>.
  66  */
  67 int32_t
  68 rte_ipv6_fragment_packet(struct rte_mbuf *pkt_in,
  69         struct rte_mbuf **pkts_out,
  70         uint16_t nb_pkts_out,
  71         uint16_t mtu_size,
  72         struct rte_mempool *pool_direct,
  73         struct rte_mempool *pool_indirect)
  74 {
  75         struct rte_mbuf *in_seg = NULL;
  76         struct ipv6_hdr *in_hdr;
  77         uint32_t out_pkt_pos, in_seg_data_pos;
  78         uint32_t more_in_segs;
  79         uint16_t fragment_offset, frag_size;
  80
  81         frag_size = (uint16_t)(mtu_size - sizeof(struct ipv6_hdr));
  82
  83         /* Fragment size should be a multiple of 8. */
  84         RTE_ASSERT((frag_size & ~RTE_IPV6_EHDR_FO_MASK) == 0);
  85
  86         /* Check that pkts_out is big enough to hold all fragments */
  87         if (unlikely (frag_size * nb_pkts_out <
  88             (uint16_t)(pkt_in->pkt_len - sizeof (struct ipv6_hdr))))
  89                 return -EINVAL;
  90
  91         in_hdr = rte_pktmbuf_mtod(pkt_in, struct ipv6_hdr *);
  92
  93         in_seg = pkt_in;
  94         in_seg_data_pos = sizeof(struct ipv6_hdr);
  95         out_pkt_pos = 0;
  96         fragment_offset = 0;
  97
  98         more_in_segs = 1;
  99         while (likely(more_in_segs)) {
 100                 struct rte_mbuf *out_pkt = NULL, *out_seg_prev = NULL;
 101                 uint32_t more_out_segs;
 102                 struct ipv6_hdr *out_hdr;
 103
 104                 /* Allocate direct buffer */
 105                 out_pkt = rte_pktmbuf_alloc(pool_direct);
 106                 if (unlikely(out_pkt == NULL)) {
 107                         __free_fragments(pkts_out, out_pkt_pos);
 108                         return -ENOMEM;
 109                 }
 110
 111                 /* Reserve space for the IP header that will be built later */
 112                 out_pkt->data_len = sizeof(struct ipv6_hdr) + sizeof(struct ipv6_extension_fragment);
 113                 out_pkt->pkt_len  = sizeof(struct ipv6_hdr) + sizeof(struct ipv6_extension_fragment);
 114
 115                 out_seg_prev = out_pkt;
 116                 more_out_segs = 1;
 117                 while (likely(more_out_segs && more_in_segs)) {
 118                         struct rte_mbuf *out_seg = NULL;
 119                         uint32_t len;
 120
 121                         /* Allocate indirect buffer */
 122                         out_seg = rte_pktmbuf_alloc(pool_indirect);
 123                         if (unlikely(out_seg == NULL)) {
 124                                 rte_pktmbuf_free(out_pkt);
 125                                 __free_fragments(pkts_out, out_pkt_pos);
 126                                 return -ENOMEM;
 127                         }
 128                         out_seg_prev->next = out_seg;
 129                         out_seg_prev = out_seg;
 130
 131                         /* Prepare indirect buffer */
 132                         rte_pktmbuf_attach(out_seg, in_seg);
 133                         len = mtu_size - out_pkt->pkt_len;
 134                         if (len > (in_seg->data_len - in_seg_data_pos)) {
 135                                 len = in_seg->data_len - in_seg_data_pos;
 136                         }
 137                         out_seg->data_off = in_seg->data_off + in_seg_data_pos;
 138                         out_seg->data_len = (uint16_t)len;
 139                         out_pkt->pkt_len = (uint16_t)(len +
 140                             out_pkt->pkt_len);
 141                         out_pkt->nb_segs += 1;
 142                         in_seg_data_pos += len;
 143
 144                         /* Current output packet (i.e. fragment) done ? */
 145                         if (unlikely(out_pkt->pkt_len >= mtu_size)) {
 146                                 more_out_segs = 0;
 147                         }
 148
 149                         /* Current input segment done ? */
 150                         if (unlikely(in_seg_data_pos == in_seg->data_len)) {
 151                                 in_seg = in_seg->next;
 152                                 in_seg_data_pos = 0;
 153
 154                                 if (unlikely(in_seg == NULL)) {
 155                                         more_in_segs = 0;
 156                                 }
 157                         }
 158                 }
 159
 160                 /* Build the IP header */
 161
 162                 out_hdr = rte_pktmbuf_mtod(out_pkt, struct ipv6_hdr *);
 163
 164                 __fill_ipv6hdr_frag(out_hdr, in_hdr,
 165                     (uint16_t) out_pkt->pkt_len - sizeof(struct ipv6_hdr),
 166                     fragment_offset, more_in_segs);
 167
 168                 fragment_offset = (uint16_t)(fragment_offset +
 169                     out_pkt->pkt_len - sizeof(struct ipv6_hdr)
 170                         - sizeof(struct ipv6_extension_fragment));
 171
 172                 /* Write the fragment to the output list */
 173                 pkts_out[out_pkt_pos] = out_pkt;
 174                 out_pkt_pos ++;
 175         }
 176
 177         return out_pkt_pos;
 178 }