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37 #include <rte_memcpy.h>
38 #include <rte_mempool.h>
39 #include <rte_debug.h>
41 #include "ip_frag_common.h"
44 #define IPV4_HDR_DF_SHIFT 14
45 #define IPV4_HDR_MF_SHIFT 13
46 #define IPV4_HDR_FO_SHIFT 3
48 #define IPV4_HDR_DF_MASK (1 << IPV4_HDR_DF_SHIFT)
49 #define IPV4_HDR_MF_MASK (1 << IPV4_HDR_MF_SHIFT)
51 #define IPV4_HDR_FO_ALIGN (1 << IPV4_HDR_FO_SHIFT)
53 static inline void __fill_ipv4hdr_frag(struct ipv4_hdr *dst,
54 const struct ipv4_hdr *src, uint16_t len, uint16_t fofs,
55 uint16_t dofs, uint32_t mf)
57 rte_memcpy(dst, src, sizeof(*dst));
58 fofs = (uint16_t)(fofs + (dofs >> IPV4_HDR_FO_SHIFT));
59 fofs = (uint16_t)(fofs | mf << IPV4_HDR_MF_SHIFT);
60 dst->fragment_offset = rte_cpu_to_be_16(fofs);
61 dst->total_length = rte_cpu_to_be_16(len);
62 dst->hdr_checksum = 0;
65 static inline void __free_fragments(struct rte_mbuf *mb[], uint32_t num)
68 for (i = 0; i != num; i++)
69 rte_pktmbuf_free(mb[i]);
75 * This function implements the fragmentation of IPv4 packets.
80 * Array storing the output fragments.
82 * Size in bytes of the Maximum Transfer Unit (MTU) for the outgoing IPv4
83 * datagrams. This value includes the size of the IPv4 header.
85 * MBUF pool used for allocating direct buffers for the output fragments.
86 * @param pool_indirect
87 * MBUF pool used for allocating indirect buffers for the output fragments.
89 * Upon successful completion - number of output fragments placed
90 * in the pkts_out array.
91 * Otherwise - (-1) * <errno>.
94 rte_ipv4_fragment_packet(struct rte_mbuf *pkt_in,
95 struct rte_mbuf **pkts_out,
98 struct rte_mempool *pool_direct,
99 struct rte_mempool *pool_indirect)
101 struct rte_mbuf *in_seg = NULL;
102 struct ipv4_hdr *in_hdr;
103 uint32_t out_pkt_pos, in_seg_data_pos;
104 uint32_t more_in_segs;
105 uint16_t fragment_offset, flag_offset, frag_size;
106 uint16_t frag_bytes_remaining;
109 * Ensure the IP payload length of all fragments is aligned to a
110 * multiple of 8 bytes as per RFC791 section 2.3.
112 frag_size = RTE_ALIGN_FLOOR((mtu_size - sizeof(struct ipv4_hdr)),
115 in_hdr = rte_pktmbuf_mtod(pkt_in, struct ipv4_hdr *);
116 flag_offset = rte_cpu_to_be_16(in_hdr->fragment_offset);
118 /* If Don't Fragment flag is set */
119 if (unlikely ((flag_offset & IPV4_HDR_DF_MASK) != 0))
122 /* Check that pkts_out is big enough to hold all fragments */
123 if (unlikely(frag_size * nb_pkts_out <
124 (uint16_t)(pkt_in->pkt_len - sizeof (struct ipv4_hdr))))
128 in_seg_data_pos = sizeof(struct ipv4_hdr);
133 while (likely(more_in_segs)) {
134 struct rte_mbuf *out_pkt = NULL, *out_seg_prev = NULL;
135 uint32_t more_out_segs;
136 struct ipv4_hdr *out_hdr;
138 /* Allocate direct buffer */
139 out_pkt = rte_pktmbuf_alloc(pool_direct);
140 if (unlikely(out_pkt == NULL)) {
141 __free_fragments(pkts_out, out_pkt_pos);
145 /* Reserve space for the IP header that will be built later */
146 out_pkt->data_len = sizeof(struct ipv4_hdr);
147 out_pkt->pkt_len = sizeof(struct ipv4_hdr);
148 frag_bytes_remaining = frag_size;
150 out_seg_prev = out_pkt;
152 while (likely(more_out_segs && more_in_segs)) {
153 struct rte_mbuf *out_seg = NULL;
156 /* Allocate indirect buffer */
157 out_seg = rte_pktmbuf_alloc(pool_indirect);
158 if (unlikely(out_seg == NULL)) {
159 rte_pktmbuf_free(out_pkt);
160 __free_fragments(pkts_out, out_pkt_pos);
163 out_seg_prev->next = out_seg;
164 out_seg_prev = out_seg;
166 /* Prepare indirect buffer */
167 rte_pktmbuf_attach(out_seg, in_seg);
168 len = frag_bytes_remaining;
169 if (len > (in_seg->data_len - in_seg_data_pos)) {
170 len = in_seg->data_len - in_seg_data_pos;
172 out_seg->data_off = in_seg->data_off + in_seg_data_pos;
173 out_seg->data_len = (uint16_t)len;
174 out_pkt->pkt_len = (uint16_t)(len +
176 out_pkt->nb_segs += 1;
177 in_seg_data_pos += len;
178 frag_bytes_remaining -= len;
180 /* Current output packet (i.e. fragment) done ? */
181 if (unlikely(frag_bytes_remaining == 0))
184 /* Current input segment done ? */
185 if (unlikely(in_seg_data_pos == in_seg->data_len)) {
186 in_seg = in_seg->next;
189 if (unlikely(in_seg == NULL))
194 /* Build the IP header */
196 out_hdr = rte_pktmbuf_mtod(out_pkt, struct ipv4_hdr *);
198 __fill_ipv4hdr_frag(out_hdr, in_hdr,
199 (uint16_t)out_pkt->pkt_len,
200 flag_offset, fragment_offset, more_in_segs);
202 fragment_offset = (uint16_t)(fragment_offset +
203 out_pkt->pkt_len - sizeof(struct ipv4_hdr));
205 out_pkt->ol_flags |= PKT_TX_IP_CKSUM;
206 out_pkt->l3_len = sizeof(struct ipv4_hdr);
208 /* Write the fragment to the output list */
209 pkts_out[out_pkt_pos] = out_pkt;