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_ether.h> 9 10 #include "ip_frag_common.h" 11 12 /* Fragment Offset */ 13 #define RTE_IPV4_HDR_DF_SHIFT 14 14 #define RTE_IPV4_HDR_MF_SHIFT 13 15 #define RTE_IPV4_HDR_FO_SHIFT 3 16 17 #define IPV4_HDR_DF_MASK (1 << RTE_IPV4_HDR_DF_SHIFT) 18 #define IPV4_HDR_MF_MASK (1 << RTE_IPV4_HDR_MF_SHIFT) 19 20 #define IPV4_HDR_FO_ALIGN (1 << RTE_IPV4_HDR_FO_SHIFT) 21 22 #define IPV4_HDR_MAX_LEN 60 23 24 static inline void __fill_ipv4hdr_frag(struct rte_ipv4_hdr *dst, 25 const struct rte_ipv4_hdr *src, uint16_t header_len, 26 uint16_t len, uint16_t fofs, uint16_t dofs, uint32_t mf) 27 { 28 memcpy(dst, src, header_len); 29 fofs = (uint16_t)(fofs + (dofs >> RTE_IPV4_HDR_FO_SHIFT)); 30 fofs = (uint16_t)(fofs | mf << RTE_IPV4_HDR_MF_SHIFT); 31 dst->fragment_offset = rte_cpu_to_be_16(fofs); 32 dst->total_length = rte_cpu_to_be_16(len); 33 dst->hdr_checksum = 0; 34 } 35 36 static inline void __free_fragments(struct rte_mbuf *mb[], uint32_t num) 37 { 38 uint32_t i; 39 for (i = 0; i != num; i++) 40 rte_pktmbuf_free(mb[i]); 41 } 42 43 static inline uint16_t __create_ipopt_frag_hdr(uint8_t *iph, 44 uint16_t ipopt_len, uint8_t *ipopt_frag_hdr) 45 { 46 uint16_t len = ipopt_len; 47 struct rte_ipv4_hdr *iph_opt = (struct rte_ipv4_hdr *)ipopt_frag_hdr; 48 49 ipopt_len = 0; 50 memcpy(ipopt_frag_hdr, iph, sizeof(struct rte_ipv4_hdr)); 51 ipopt_frag_hdr += sizeof(struct rte_ipv4_hdr); 52 53 uint8_t *p_opt = iph + sizeof(struct rte_ipv4_hdr); 54 55 while (len > 0) { 56 if (unlikely(*p_opt == RTE_IPV4_HDR_OPT_NOP)) { 57 len--; 58 p_opt++; 59 continue; 60 } else if (unlikely(*p_opt == RTE_IPV4_HDR_OPT_EOL)) 61 break; 62 63 if (unlikely(p_opt[1] < 2 || p_opt[1] > len)) 64 break; 65 66 if (RTE_IPV4_HDR_OPT_COPIED(*p_opt)) { 67 memcpy(ipopt_frag_hdr + ipopt_len, 68 p_opt, p_opt[1]); 69 ipopt_len += p_opt[1]; 70 } 71 72 len -= p_opt[1]; 73 p_opt += p_opt[1]; 74 } 75 76 len = RTE_ALIGN_CEIL(ipopt_len, RTE_IPV4_IHL_MULTIPLIER); 77 memset(ipopt_frag_hdr + ipopt_len, 78 RTE_IPV4_HDR_OPT_EOL, len - ipopt_len); 79 ipopt_len = len; 80 iph_opt->ihl = (sizeof(struct rte_ipv4_hdr) + ipopt_len) / 81 RTE_IPV4_IHL_MULTIPLIER; 82 83 return ipopt_len; 84 } 85 86 /** 87 * IPv4 fragmentation. 88 * 89 * This function implements the fragmentation of IPv4 packets. 90 * 91 * @param pkt_in 92 * The input packet. 93 * @param pkts_out 94 * Array storing the output fragments. 95 * @param mtu_size 96 * Size in bytes of the Maximum Transfer Unit (MTU) for the outgoing IPv4 97 * datagrams. This value includes the size of the IPv4 header. 98 * @param pool_direct 99 * MBUF pool used for allocating direct buffers for the output fragments. 100 * @param pool_indirect 101 * MBUF pool used for allocating indirect buffers for the output fragments. 102 * @return 103 * Upon successful completion - number of output fragments placed 104 * in the pkts_out array. 105 * Otherwise - (-1) * <errno>. 106 */ 107 int32_t 108 rte_ipv4_fragment_packet(struct rte_mbuf *pkt_in, 109 struct rte_mbuf **pkts_out, 110 uint16_t nb_pkts_out, 111 uint16_t mtu_size, 112 struct rte_mempool *pool_direct, 113 struct rte_mempool *pool_indirect) 114 { 115 struct rte_mbuf *in_seg = NULL; 116 struct rte_ipv4_hdr *in_hdr; 117 uint32_t out_pkt_pos, in_seg_data_pos; 118 uint32_t more_in_segs; 119 uint16_t fragment_offset, flag_offset, frag_size, header_len; 120 uint16_t frag_bytes_remaining; 121 uint8_t ipopt_frag_hdr[IPV4_HDR_MAX_LEN]; 122 uint16_t ipopt_len; 123 124 /* 125 * Formal parameter checking. 126 */ 127 if (unlikely(pkt_in == NULL) || unlikely(pkts_out == NULL) || 128 unlikely(nb_pkts_out == 0) || 129 unlikely(pool_direct == NULL) || unlikely(pool_indirect == NULL) || 130 unlikely(mtu_size < RTE_ETHER_MIN_MTU)) 131 return -EINVAL; 132 133 in_hdr = rte_pktmbuf_mtod(pkt_in, struct rte_ipv4_hdr *); 134 header_len = (in_hdr->version_ihl & RTE_IPV4_HDR_IHL_MASK) * 135 RTE_IPV4_IHL_MULTIPLIER; 136 137 /* Check IP header length */ 138 if (unlikely(pkt_in->data_len < header_len) || 139 unlikely(mtu_size < header_len)) 140 return -EINVAL; 141 142 /* 143 * Ensure the IP payload length of all fragments is aligned to a 144 * multiple of 8 bytes as per RFC791 section 2.3. 145 */ 146 frag_size = RTE_ALIGN_FLOOR((mtu_size - header_len), 147 IPV4_HDR_FO_ALIGN); 148 149 flag_offset = rte_cpu_to_be_16(in_hdr->fragment_offset); 150 151 /* If Don't Fragment flag is set */ 152 if (unlikely ((flag_offset & IPV4_HDR_DF_MASK) != 0)) 153 return -ENOTSUP; 154 155 /* Check that pkts_out is big enough to hold all fragments */ 156 if (unlikely(frag_size * nb_pkts_out < 157 (uint16_t)(pkt_in->pkt_len - header_len))) 158 return -EINVAL; 159 160 in_seg = pkt_in; 161 in_seg_data_pos = header_len; 162 out_pkt_pos = 0; 163 fragment_offset = 0; 164 165 ipopt_len = header_len - sizeof(struct rte_ipv4_hdr); 166 if (unlikely(ipopt_len > RTE_IPV4_HDR_OPT_MAX_LEN)) 167 return -EINVAL; 168 169 more_in_segs = 1; 170 while (likely(more_in_segs)) { 171 struct rte_mbuf *out_pkt = NULL, *out_seg_prev = NULL; 172 uint32_t more_out_segs; 173 struct rte_ipv4_hdr *out_hdr; 174 175 /* Allocate direct buffer */ 176 out_pkt = rte_pktmbuf_alloc(pool_direct); 177 if (unlikely(out_pkt == NULL)) { 178 __free_fragments(pkts_out, out_pkt_pos); 179 return -ENOMEM; 180 } 181 182 /* Reserve space for the IP header that will be built later */ 183 out_pkt->data_len = header_len; 184 out_pkt->pkt_len = header_len; 185 frag_bytes_remaining = frag_size; 186 187 out_seg_prev = out_pkt; 188 more_out_segs = 1; 189 while (likely(more_out_segs && more_in_segs)) { 190 struct rte_mbuf *out_seg = NULL; 191 uint32_t len; 192 193 /* Allocate indirect buffer */ 194 out_seg = rte_pktmbuf_alloc(pool_indirect); 195 if (unlikely(out_seg == NULL)) { 196 rte_pktmbuf_free(out_pkt); 197 __free_fragments(pkts_out, out_pkt_pos); 198 return -ENOMEM; 199 } 200 out_seg_prev->next = out_seg; 201 out_seg_prev = out_seg; 202 203 /* Prepare indirect buffer */ 204 rte_pktmbuf_attach(out_seg, in_seg); 205 len = frag_bytes_remaining; 206 if (len > (in_seg->data_len - in_seg_data_pos)) { 207 len = in_seg->data_len - in_seg_data_pos; 208 } 209 out_seg->data_off = in_seg->data_off + in_seg_data_pos; 210 out_seg->data_len = (uint16_t)len; 211 out_pkt->pkt_len = (uint16_t)(len + 212 out_pkt->pkt_len); 213 out_pkt->nb_segs += 1; 214 in_seg_data_pos += len; 215 frag_bytes_remaining -= len; 216 217 /* Current output packet (i.e. fragment) done ? */ 218 if (unlikely(frag_bytes_remaining == 0)) 219 more_out_segs = 0; 220 221 /* Current input segment done ? */ 222 if (unlikely(in_seg_data_pos == in_seg->data_len)) { 223 in_seg = in_seg->next; 224 in_seg_data_pos = 0; 225 226 if (unlikely(in_seg == NULL)) 227 more_in_segs = 0; 228 } 229 } 230 231 /* Build the IP header */ 232 233 out_hdr = rte_pktmbuf_mtod(out_pkt, struct rte_ipv4_hdr *); 234 235 __fill_ipv4hdr_frag(out_hdr, in_hdr, header_len, 236 (uint16_t)out_pkt->pkt_len, 237 flag_offset, fragment_offset, more_in_segs); 238 239 if (unlikely((fragment_offset == 0) && (ipopt_len) && 240 ((flag_offset & RTE_IPV4_HDR_OFFSET_MASK) == 0))) { 241 ipopt_len = __create_ipopt_frag_hdr((uint8_t *)in_hdr, 242 ipopt_len, ipopt_frag_hdr); 243 fragment_offset = (uint16_t)(fragment_offset + 244 out_pkt->pkt_len - header_len); 245 out_pkt->l3_len = header_len; 246 247 header_len = sizeof(struct rte_ipv4_hdr) + ipopt_len; 248 in_hdr = (struct rte_ipv4_hdr *)ipopt_frag_hdr; 249 } else { 250 fragment_offset = (uint16_t)(fragment_offset + 251 out_pkt->pkt_len - header_len); 252 out_pkt->l3_len = header_len; 253 } 254 255 /* Write the fragment to the output list */ 256 pkts_out[out_pkt_pos] = out_pkt; 257 out_pkt_pos ++; 258 } 259 260 return out_pkt_pos; 261 } 262