lib/librte_ipsec/iph.h

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2018 Intel Corporation
   3  */
   4
   5 #ifndef _IPH_H_
   6 #define _IPH_H_
   7
   8 #include <rte_ip.h>
   9
  10 /**
  11  * @file iph.h
  12  * Contains functions/structures/macros to manipulate IPv4/IPv6 headers
  13  * used internally by ipsec library.
  14  */
  15
  16 /*
  17  * Move preceding (L3) headers down to remove ESP header and IV.
  18  */
  19 static inline void
  20 remove_esph(char *np, char *op, uint32_t hlen)
  21 {
  22         uint32_t i;
  23
  24         for (i = hlen; i-- != 0; np[i] = op[i])
  25                 ;
  26 }
  27
  28 /*
  29  * Move preceding (L3) headers up to free space for ESP header and IV.
  30  */
  31 static inline void
  32 insert_esph(char *np, char *op, uint32_t hlen)
  33 {
  34         uint32_t i;
  35
  36         for (i = 0; i != hlen; i++)
  37                 np[i] = op[i];
  38 }
  39
  40 /* update original ip header fields for transport case */
  41 static inline int
  42 update_trs_l3hdr(const struct rte_ipsec_sa *sa, void *p, uint32_t plen,
  43                 uint32_t l2len, uint32_t l3len, uint8_t proto)
  44 {
  45         int32_t rc;
  46
  47         /* IPv4 */
  48         if ((sa->type & RTE_IPSEC_SATP_IPV_MASK) == RTE_IPSEC_SATP_IPV4) {
  49                 struct rte_ipv4_hdr *v4h;
  50
  51                 v4h = p;
  52                 rc = v4h->next_proto_id;
  53                 v4h->next_proto_id = proto;
  54                 v4h->total_length = rte_cpu_to_be_16(plen - l2len);
  55         /* IPv6 */
  56         } else {
  57                 struct rte_ipv6_hdr *v6h;
  58                 uint8_t *p_nh;
  59
  60                 v6h = p;
  61
  62                 /* basic IPv6 header with no extensions */
  63                 if (l3len == sizeof(struct rte_ipv6_hdr))
  64                         p_nh = &v6h->proto;
  65
  66                 /* IPv6 with extensions */
  67                 else {
  68                         size_t ext_len;
  69                         int nh;
  70                         uint8_t *pd, *plimit;
  71
  72                         /* locate last extension within l3len bytes */
  73                         pd = (uint8_t *)p;
  74                         plimit = pd + l3len;
  75                         ext_len = sizeof(struct rte_ipv6_hdr);
  76                         nh = v6h->proto;
  77                         while (pd + ext_len < plimit) {
  78                                 pd += ext_len;
  79                                 nh = rte_ipv6_get_next_ext(pd, nh, &ext_len);
  80                                 if (unlikely(nh < 0))
  81                                         return -EINVAL;
  82                         }
  83
  84                         /* invalid l3len - extension exceeds header length */
  85                         if (unlikely(pd + ext_len != plimit))
  86                                 return -EINVAL;
  87
  88                         /* save last extension offset */
  89                         p_nh = pd;
  90                 }
  91
  92                 /* update header type; return original value */
  93                 rc = *p_nh;
  94                 *p_nh = proto;
  95
  96                 /* fix packet length */
  97                 v6h->payload_len = rte_cpu_to_be_16(plen - l2len -
  98                                 sizeof(*v6h));
  99         }
 100
 101         return rc;
 102 }
 103
 104 /* update original and new ip header fields for tunnel case */
 105 static inline void
 106 update_tun_l3hdr(const struct rte_ipsec_sa *sa, void *p, uint32_t plen,
 107                 uint32_t l2len, rte_be16_t pid)
 108 {
 109         struct rte_ipv4_hdr *v4h;
 110         struct rte_ipv6_hdr *v6h;
 111
 112         if (sa->type & RTE_IPSEC_SATP_MODE_TUNLV4) {
 113                 v4h = p;
 114                 v4h->packet_id = pid;
 115                 v4h->total_length = rte_cpu_to_be_16(plen - l2len);
 116         } else {
 117                 v6h = p;
 118                 v6h->payload_len = rte_cpu_to_be_16(plen - l2len -
 119                                 sizeof(*v6h));
 120         }
 121 }
 122
 123 #endif /* _IPH_H_ */