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 static inline void
__fill_ipv6hdr_frag(struct rte_ipv6_hdr * dst,const struct rte_ipv6_hdr * src,uint16_t len,uint16_t fofs,uint32_t mf)20 __fill_ipv6hdr_frag(struct rte_ipv6_hdr *dst,
21 const struct rte_ipv6_hdr *src, uint16_t len, uint16_t fofs,
22 uint32_t mf)
23 {
24 struct rte_ipv6_fragment_ext *fh;
25
26 rte_memcpy(dst, src, sizeof(*dst));
27 dst->payload_len = rte_cpu_to_be_16(len);
28 dst->proto = IPPROTO_FRAGMENT;
29
30 fh = (struct rte_ipv6_fragment_ext *) ++dst;
31 fh->next_header = src->proto;
32 fh->reserved = 0;
33 fh->frag_data = rte_cpu_to_be_16(RTE_IPV6_SET_FRAG_DATA(fofs, mf));
34 fh->id = 0;
35 }
36
37 static inline void
__free_fragments(struct rte_mbuf * mb[],uint32_t num)38 __free_fragments(struct rte_mbuf *mb[], uint32_t num)
39 {
40 uint32_t i;
41 for (i = 0; i < num; i++)
42 rte_pktmbuf_free(mb[i]);
43 }
44
45 /**
46 * IPv6 fragmentation.
47 *
48 * This function implements the fragmentation of IPv6 packets.
49 *
50 * @param pkt_in
51 * The input packet.
52 * @param pkts_out
53 * Array storing the output fragments.
54 * @param mtu_size
55 * Size in bytes of the Maximum Transfer Unit (MTU) for the outgoing IPv6
56 * datagrams. This value includes the size of the IPv6 header.
57 * @param pool_direct
58 * MBUF pool used for allocating direct buffers for the output fragments.
59 * @param pool_indirect
60 * MBUF pool used for allocating indirect buffers for the output fragments.
61 * @return
62 * Upon successful completion - number of output fragments placed
63 * in the pkts_out array.
64 * Otherwise - (-1) * <errno>.
65 */
66 int32_t
rte_ipv6_fragment_packet(struct rte_mbuf * pkt_in,struct rte_mbuf ** pkts_out,uint16_t nb_pkts_out,uint16_t mtu_size,struct rte_mempool * pool_direct,struct rte_mempool * pool_indirect)67 rte_ipv6_fragment_packet(struct rte_mbuf *pkt_in,
68 struct rte_mbuf **pkts_out,
69 uint16_t nb_pkts_out,
70 uint16_t mtu_size,
71 struct rte_mempool *pool_direct,
72 struct rte_mempool *pool_indirect)
73 {
74 struct rte_mbuf *in_seg = NULL;
75 struct rte_ipv6_hdr *in_hdr;
76 uint32_t out_pkt_pos, in_seg_data_pos;
77 uint32_t more_in_segs;
78 uint16_t fragment_offset, frag_size;
79 uint64_t frag_bytes_remaining;
80
81 /*
82 * Formal parameter checking.
83 */
84 if (unlikely(pkt_in == NULL) || unlikely(pkts_out == NULL) ||
85 unlikely(nb_pkts_out == 0) ||
86 unlikely(pool_direct == NULL) || unlikely(pool_indirect == NULL) ||
87 unlikely(mtu_size < RTE_IPV6_MIN_MTU))
88 return -EINVAL;
89
90 /*
91 * Ensure the IP payload length of all fragments (except the
92 * last fragment) are a multiple of 8 bytes per RFC2460.
93 */
94
95 frag_size = mtu_size - sizeof(struct rte_ipv6_hdr) -
96 sizeof(struct rte_ipv6_fragment_ext);
97 frag_size = RTE_ALIGN_FLOOR(frag_size, RTE_IPV6_EHDR_FO_ALIGN);
98
99 /* Check that pkts_out is big enough to hold all fragments */
100 if (unlikely (frag_size * nb_pkts_out <
101 (uint16_t)(pkt_in->pkt_len - sizeof(struct rte_ipv6_hdr))))
102 return -EINVAL;
103
104 in_hdr = rte_pktmbuf_mtod(pkt_in, struct rte_ipv6_hdr *);
105
106 in_seg = pkt_in;
107 in_seg_data_pos = sizeof(struct rte_ipv6_hdr);
108 out_pkt_pos = 0;
109 fragment_offset = 0;
110
111 more_in_segs = 1;
112 while (likely(more_in_segs)) {
113 struct rte_mbuf *out_pkt = NULL, *out_seg_prev = NULL;
114 uint32_t more_out_segs;
115 struct rte_ipv6_hdr *out_hdr;
116
117 /* Allocate direct buffer */
118 out_pkt = rte_pktmbuf_alloc(pool_direct);
119 if (unlikely(out_pkt == NULL)) {
120 __free_fragments(pkts_out, out_pkt_pos);
121 return -ENOMEM;
122 }
123
124 /* Reserve space for the IP header that will be built later */
125 out_pkt->data_len = sizeof(struct rte_ipv6_hdr) +
126 sizeof(struct rte_ipv6_fragment_ext);
127 out_pkt->pkt_len = sizeof(struct rte_ipv6_hdr) +
128 sizeof(struct rte_ipv6_fragment_ext);
129 frag_bytes_remaining = frag_size;
130
131 out_seg_prev = out_pkt;
132 more_out_segs = 1;
133 while (likely(more_out_segs && more_in_segs)) {
134 struct rte_mbuf *out_seg = NULL;
135 uint32_t len;
136
137 /* Allocate indirect buffer */
138 out_seg = rte_pktmbuf_alloc(pool_indirect);
139 if (unlikely(out_seg == NULL)) {
140 rte_pktmbuf_free(out_pkt);
141 __free_fragments(pkts_out, out_pkt_pos);
142 return -ENOMEM;
143 }
144 out_seg_prev->next = out_seg;
145 out_seg_prev = out_seg;
146
147 /* Prepare indirect buffer */
148 rte_pktmbuf_attach(out_seg, in_seg);
149 len = frag_bytes_remaining;
150 if (len > (in_seg->data_len - in_seg_data_pos)) {
151 len = in_seg->data_len - in_seg_data_pos;
152 }
153 out_seg->data_off = in_seg->data_off + in_seg_data_pos;
154 out_seg->data_len = (uint16_t)len;
155 out_pkt->pkt_len = (uint16_t)(len +
156 out_pkt->pkt_len);
157 out_pkt->nb_segs += 1;
158 in_seg_data_pos += len;
159 frag_bytes_remaining -= len;
160
161 /* Current output packet (i.e. fragment) done ? */
162 if (unlikely(frag_bytes_remaining == 0))
163 more_out_segs = 0;
164
165 /* Current input segment done ? */
166 if (unlikely(in_seg_data_pos == in_seg->data_len)) {
167 in_seg = in_seg->next;
168 in_seg_data_pos = 0;
169
170 if (unlikely(in_seg == NULL)) {
171 more_in_segs = 0;
172 }
173 }
174 }
175
176 /* Build the IP header */
177
178 out_hdr = rte_pktmbuf_mtod(out_pkt, struct rte_ipv6_hdr *);
179
180 __fill_ipv6hdr_frag(out_hdr, in_hdr,
181 (uint16_t) out_pkt->pkt_len - sizeof(struct rte_ipv6_hdr),
182 fragment_offset, more_in_segs);
183
184 fragment_offset = (uint16_t)(fragment_offset +
185 out_pkt->pkt_len - sizeof(struct rte_ipv6_hdr)
186 - sizeof(struct rte_ipv6_fragment_ext));
187
188 /* Write the fragment to the output list */
189 pkts_out[out_pkt_pos] = out_pkt;
190 out_pkt_pos ++;
191 }
192
193 return out_pkt_pos;
194 }
195