1 /* SPDX-License-Identifier: BSD-3-Clause 2 * Copyright(c) 2010-2014 Intel Corporation 3 */ 4 5 #include <stddef.h> 6 7 #include <rte_memcpy.h> 8 9 #include "ip_frag_common.h" 10 11 /** 12 * @file 13 * IPv6 reassemble 14 * 15 * Implementation of IPv6 reassembly. 16 */ 17 18 static inline void 19 ip_frag_memmove(char *dst, char *src, int len) 20 { 21 int i; 22 23 /* go backwards to make sure we don't overwrite anything important */ 24 for (i = len - 1; i >= 0; i--) 25 dst[i] = src[i]; 26 } 27 28 /* 29 * Reassemble fragments into one packet. 30 */ 31 struct rte_mbuf * 32 ipv6_frag_reassemble(struct ip_frag_pkt *fp) 33 { 34 struct rte_ipv6_hdr *ip_hdr; 35 struct rte_ipv6_fragment_ext *frag_hdr; 36 struct rte_mbuf *m, *prev; 37 uint32_t i, n, ofs, first_len; 38 uint32_t last_len, move_len, payload_len; 39 uint32_t curr_idx = 0; 40 41 first_len = fp->frags[IP_FIRST_FRAG_IDX].len; 42 n = fp->last_idx - 1; 43 44 /*start from the last fragment. */ 45 m = fp->frags[IP_LAST_FRAG_IDX].mb; 46 ofs = fp->frags[IP_LAST_FRAG_IDX].ofs; 47 last_len = fp->frags[IP_LAST_FRAG_IDX].len; 48 curr_idx = IP_LAST_FRAG_IDX; 49 50 payload_len = ofs + last_len; 51 52 while (ofs != first_len) { 53 54 prev = m; 55 56 for (i = n; i != IP_FIRST_FRAG_IDX && ofs != first_len; i--) { 57 58 /* previous fragment found. */ 59 if (fp->frags[i].ofs + fp->frags[i].len == ofs) { 60 61 RTE_ASSERT(curr_idx != i); 62 63 /* adjust start of the last fragment data. */ 64 rte_pktmbuf_adj(m, 65 (uint16_t)(m->l2_len + m->l3_len)); 66 rte_pktmbuf_chain(fp->frags[i].mb, m); 67 68 /* this mbuf should not be accessed directly */ 69 fp->frags[curr_idx].mb = NULL; 70 curr_idx = i; 71 72 /* update our last fragment and offset. */ 73 m = fp->frags[i].mb; 74 ofs = fp->frags[i].ofs; 75 } 76 } 77 78 /* error - hole in the packet. */ 79 if (m == prev) { 80 return NULL; 81 } 82 } 83 84 /* chain with the first fragment. */ 85 rte_pktmbuf_adj(m, (uint16_t)(m->l2_len + m->l3_len)); 86 rte_pktmbuf_chain(fp->frags[IP_FIRST_FRAG_IDX].mb, m); 87 fp->frags[curr_idx].mb = NULL; 88 m = fp->frags[IP_FIRST_FRAG_IDX].mb; 89 fp->frags[IP_FIRST_FRAG_IDX].mb = NULL; 90 91 /* update ipv6 header for the reassembled datagram */ 92 ip_hdr = rte_pktmbuf_mtod_offset(m, struct rte_ipv6_hdr *, m->l2_len); 93 94 ip_hdr->payload_len = rte_cpu_to_be_16(payload_len); 95 96 /* 97 * remove fragmentation header. note that per RFC2460, we need to update 98 * the last non-fragmentable header with the "next header" field to contain 99 * type of the first fragmentable header, but we currently don't support 100 * other headers, so we assume there are no other headers and thus update 101 * the main IPv6 header instead. 102 */ 103 move_len = m->l2_len + m->l3_len - sizeof(*frag_hdr); 104 frag_hdr = (struct rte_ipv6_fragment_ext *) (ip_hdr + 1); 105 ip_hdr->proto = frag_hdr->next_header; 106 107 ip_frag_memmove(rte_pktmbuf_mtod_offset(m, char *, sizeof(*frag_hdr)), 108 rte_pktmbuf_mtod(m, char*), move_len); 109 110 rte_pktmbuf_adj(m, sizeof(*frag_hdr)); 111 112 return m; 113 } 114 115 /* 116 * Process new mbuf with fragment of IPV6 datagram. 117 * Incoming mbuf should have its l2_len/l3_len fields setup correctly. 118 * @param tbl 119 * Table where to lookup/add the fragmented packet. 120 * @param mb 121 * Incoming mbuf with IPV6 fragment. 122 * @param tms 123 * Fragment arrival timestamp. 124 * @param ip_hdr 125 * Pointer to the IPV6 header. 126 * @param frag_hdr 127 * Pointer to the IPV6 fragment extension header. 128 * @return 129 * Pointer to mbuf for reassembled packet, or NULL if: 130 * - an error occurred. 131 * - not all fragments of the packet are collected yet. 132 */ 133 #define MORE_FRAGS(x) (((x) & 0x100) >> 8) 134 #define FRAG_OFFSET(x) (rte_cpu_to_be_16(x) >> 3) 135 struct rte_mbuf * 136 rte_ipv6_frag_reassemble_packet(struct rte_ip_frag_tbl *tbl, 137 struct rte_ip_frag_death_row *dr, struct rte_mbuf *mb, uint64_t tms, 138 struct rte_ipv6_hdr *ip_hdr, struct rte_ipv6_fragment_ext *frag_hdr) 139 { 140 struct ip_frag_pkt *fp; 141 struct ip_frag_key key; 142 uint16_t ip_ofs; 143 int32_t ip_len; 144 int32_t trim; 145 146 rte_memcpy(&key.src_dst[0], &ip_hdr->src_addr, 16); 147 rte_memcpy(&key.src_dst[2], &ip_hdr->dst_addr, 16); 148 149 key.id = frag_hdr->id; 150 key.key_len = IPV6_KEYLEN; 151 152 ip_ofs = FRAG_OFFSET(frag_hdr->frag_data) * 8; 153 154 /* 155 * as per RFC2460, payload length contains all extension headers 156 * as well. 157 * since we don't support anything but frag headers, 158 * this is what we remove from the payload len. 159 */ 160 ip_len = rte_be_to_cpu_16(ip_hdr->payload_len) - sizeof(*frag_hdr); 161 trim = mb->pkt_len - (ip_len + mb->l3_len + mb->l2_len); 162 163 IP_FRAG_LOG(DEBUG, "%s:%d:\n" 164 "mbuf: %p, tms: %" PRIu64 165 ", key: <" IPv6_KEY_BYTES_FMT ", %#x>, " 166 "ofs: %u, len: %d, padding: %d, flags: %#x\n" 167 "tbl: %p, max_cycles: %" PRIu64 ", entry_mask: %#x, " 168 "max_entries: %u, use_entries: %u\n\n", 169 __func__, __LINE__, 170 mb, tms, IPv6_KEY_BYTES(key.src_dst), key.id, ip_ofs, ip_len, 171 trim, RTE_IPV6_GET_MF(frag_hdr->frag_data), 172 tbl, tbl->max_cycles, tbl->entry_mask, tbl->max_entries, 173 tbl->use_entries); 174 175 /* check that fragment length is greater then zero. */ 176 if (ip_len <= 0) { 177 IP_FRAG_MBUF2DR(dr, mb); 178 return NULL; 179 } 180 181 if (unlikely(trim > 0)) 182 rte_pktmbuf_trim(mb, trim); 183 184 /* try to find/add entry into the fragment's table. */ 185 fp = ip_frag_find(tbl, dr, &key, tms); 186 if (fp == NULL) { 187 IP_FRAG_MBUF2DR(dr, mb); 188 return NULL; 189 } 190 191 IP_FRAG_LOG(DEBUG, "%s:%d:\n" 192 "tbl: %p, max_entries: %u, use_entries: %u\n" 193 "ipv6_frag_pkt: %p, key: <" IPv6_KEY_BYTES_FMT ", %#x>, start: %" PRIu64 194 ", total_size: %u, frag_size: %u, last_idx: %u\n\n", 195 __func__, __LINE__, 196 tbl, tbl->max_entries, tbl->use_entries, 197 fp, IPv6_KEY_BYTES(fp->key.src_dst), fp->key.id, fp->start, 198 fp->total_size, fp->frag_size, fp->last_idx); 199 200 201 /* process the fragmented packet. */ 202 mb = ip_frag_process(fp, dr, mb, ip_ofs, ip_len, 203 MORE_FRAGS(frag_hdr->frag_data)); 204 ip_frag_inuse(tbl, fp); 205 206 IP_FRAG_LOG(DEBUG, "%s:%d:\n" 207 "mbuf: %p\n" 208 "tbl: %p, max_entries: %u, use_entries: %u\n" 209 "ipv6_frag_pkt: %p, key: <" IPv6_KEY_BYTES_FMT ", %#x>, start: %" PRIu64 210 ", total_size: %u, frag_size: %u, last_idx: %u\n\n", 211 __func__, __LINE__, mb, 212 tbl, tbl->max_entries, tbl->use_entries, 213 fp, IPv6_KEY_BYTES(fp->key.src_dst), fp->key.id, fp->start, 214 fp->total_size, fp->frag_size, fp->last_idx); 215 216 return mb; 217 } 218