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

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <stddef.h>
  35 #include <errno.h>
  36
  37 #include <rte_memcpy.h>
  38
  39 #include "ip_frag_common.h"
  40
  41 /**
  42  * @file
  43  * RTE IPv6 Fragmentation
  44  *
  45  * Implementation of IPv6 fragmentation.
  46  *
  47  */
  48
  49 static inline void
  50 __fill_ipv6hdr_frag(struct ipv6_hdr *dst,
  51                 const struct ipv6_hdr *src, uint16_t len, uint16_t fofs,
  52                 uint32_t mf)
  53 {
  54         struct ipv6_extension_fragment *fh;
  55
  56         rte_memcpy(dst, src, sizeof(*dst));
  57         dst->payload_len = rte_cpu_to_be_16(len);
  58         dst->proto = IPPROTO_FRAGMENT;
  59
  60         fh = (struct ipv6_extension_fragment *) ++dst;
  61         fh->next_header = src->proto;
  62         fh->reserved = 0;
  63         fh->frag_data = rte_cpu_to_be_16(RTE_IPV6_SET_FRAG_DATA(fofs, mf));
  64         fh->id = 0;
  65 }
  66
  67 static inline void
  68 __free_fragments(struct rte_mbuf *mb[], uint32_t num)
  69 {
  70         uint32_t i;
  71         for (i = 0; i < num; i++)
  72                 rte_pktmbuf_free(mb[i]);
  73 }
  74
  75 /**
  76  * IPv6 fragmentation.
  77  *
  78  * This function implements the fragmentation of IPv6 packets.
  79  *
  80  * @param pkt_in
  81  *   The input packet.
  82  * @param pkts_out
  83  *   Array storing the output fragments.
  84  * @param mtu_size
  85  *   Size in bytes of the Maximum Transfer Unit (MTU) for the outgoing IPv6
  86  *   datagrams. This value includes the size of the IPv6 header.
  87  * @param pool_direct
  88  *   MBUF pool used for allocating direct buffers for the output fragments.
  89  * @param pool_indirect
  90  *   MBUF pool used for allocating indirect buffers for the output fragments.
  91  * @return
  92  *   Upon successful completion - number of output fragments placed
  93  *   in the pkts_out array.
  94  *   Otherwise - (-1) * <errno>.
  95  */
  96 int32_t
  97 rte_ipv6_fragment_packet(struct rte_mbuf *pkt_in,
  98         struct rte_mbuf **pkts_out,
  99         uint16_t nb_pkts_out,
 100         uint16_t mtu_size,
 101         struct rte_mempool *pool_direct,
 102         struct rte_mempool *pool_indirect)
 103 {
 104         struct rte_mbuf *in_seg = NULL;
 105         struct ipv6_hdr *in_hdr;
 106         uint32_t out_pkt_pos, in_seg_data_pos;
 107         uint32_t more_in_segs;
 108         uint16_t fragment_offset, frag_size;
 109
 110         frag_size = (uint16_t)(mtu_size - sizeof(struct ipv6_hdr));
 111
 112         /* Fragment size should be a multiple of 8. */
 113         RTE_ASSERT((frag_size & ~RTE_IPV6_EHDR_FO_MASK) == 0);
 114
 115         /* Check that pkts_out is big enough to hold all fragments */
 116         if (unlikely (frag_size * nb_pkts_out <
 117             (uint16_t)(pkt_in->pkt_len - sizeof (struct ipv6_hdr))))
 118                 return -EINVAL;
 119
 120         in_hdr = rte_pktmbuf_mtod(pkt_in, struct ipv6_hdr *);
 121
 122         in_seg = pkt_in;
 123         in_seg_data_pos = sizeof(struct ipv6_hdr);
 124         out_pkt_pos = 0;
 125         fragment_offset = 0;
 126
 127         more_in_segs = 1;
 128         while (likely(more_in_segs)) {
 129                 struct rte_mbuf *out_pkt = NULL, *out_seg_prev = NULL;
 130                 uint32_t more_out_segs;
 131                 struct ipv6_hdr *out_hdr;
 132
 133                 /* Allocate direct buffer */
 134                 out_pkt = rte_pktmbuf_alloc(pool_direct);
 135                 if (unlikely(out_pkt == NULL)) {
 136                         __free_fragments(pkts_out, out_pkt_pos);
 137                         return -ENOMEM;
 138                 }
 139
 140                 /* Reserve space for the IP header that will be built later */
 141                 out_pkt->data_len = sizeof(struct ipv6_hdr) + sizeof(struct ipv6_extension_fragment);
 142                 out_pkt->pkt_len  = sizeof(struct ipv6_hdr) + sizeof(struct ipv6_extension_fragment);
 143
 144                 out_seg_prev = out_pkt;
 145                 more_out_segs = 1;
 146                 while (likely(more_out_segs && more_in_segs)) {
 147                         struct rte_mbuf *out_seg = NULL;
 148                         uint32_t len;
 149
 150                         /* Allocate indirect buffer */
 151                         out_seg = rte_pktmbuf_alloc(pool_indirect);
 152                         if (unlikely(out_seg == NULL)) {
 153                                 rte_pktmbuf_free(out_pkt);
 154                                 __free_fragments(pkts_out, out_pkt_pos);
 155                                 return -ENOMEM;
 156                         }
 157                         out_seg_prev->next = out_seg;
 158                         out_seg_prev = out_seg;
 159
 160                         /* Prepare indirect buffer */
 161                         rte_pktmbuf_attach(out_seg, in_seg);
 162                         len = mtu_size - out_pkt->pkt_len;
 163                         if (len > (in_seg->data_len - in_seg_data_pos)) {
 164                                 len = in_seg->data_len - in_seg_data_pos;
 165                         }
 166                         out_seg->data_off = in_seg->data_off + in_seg_data_pos;
 167                         out_seg->data_len = (uint16_t)len;
 168                         out_pkt->pkt_len = (uint16_t)(len +
 169                             out_pkt->pkt_len);
 170                         out_pkt->nb_segs += 1;
 171                         in_seg_data_pos += len;
 172
 173                         /* Current output packet (i.e. fragment) done ? */
 174                         if (unlikely(out_pkt->pkt_len >= mtu_size)) {
 175                                 more_out_segs = 0;
 176                         }
 177
 178                         /* Current input segment done ? */
 179                         if (unlikely(in_seg_data_pos == in_seg->data_len)) {
 180                                 in_seg = in_seg->next;
 181                                 in_seg_data_pos = 0;
 182
 183                                 if (unlikely(in_seg == NULL)) {
 184                                         more_in_segs = 0;
 185                                 }
 186                         }
 187                 }
 188
 189                 /* Build the IP header */
 190
 191                 out_hdr = rte_pktmbuf_mtod(out_pkt, struct ipv6_hdr *);
 192
 193                 __fill_ipv6hdr_frag(out_hdr, in_hdr,
 194                     (uint16_t) out_pkt->pkt_len - sizeof(struct ipv6_hdr),
 195                     fragment_offset, more_in_segs);
 196
 197                 fragment_offset = (uint16_t)(fragment_offset +
 198                     out_pkt->pkt_len - sizeof(struct ipv6_hdr)
 199                         - sizeof(struct ipv6_extension_fragment));
 200
 201                 /* Write the fragment to the output list */
 202                 pkts_out[out_pkt_pos] = out_pkt;
 203                 out_pkt_pos ++;
 204         }
 205
 206         return out_pkt_pos;
 207 }