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 19 static inline void 20 ip_frag_memmove(char *dst, char *src, int len) 21 { 22 int i; 23 24 /* go backwards to make sure we don't overwrite anything important */ 25 for (i = len - 1; i >= 0; i--) 26 dst[i] = src[i]; 27 } 28 29 /* 30 * Reassemble fragments into one packet. 31 */ 32 struct rte_mbuf * 33 ipv6_frag_reassemble(struct ip_frag_pkt *fp) 34 { 35 struct rte_ipv6_hdr *ip_hdr; 36 struct ipv6_extension_fragment *frag_hdr; 37 struct rte_mbuf *m, *prev; 38 uint32_t i, n, ofs, first_len; 39 uint32_t last_len, move_len, payload_len; 40 uint32_t curr_idx = 0; 41 42 first_len = fp->frags[IP_FIRST_FRAG_IDX].len; 43 n = fp->last_idx - 1; 44 45 /*start from the last fragment. */ 46 m = fp->frags[IP_LAST_FRAG_IDX].mb; 47 ofs = fp->frags[IP_LAST_FRAG_IDX].ofs; 48 last_len = fp->frags[IP_LAST_FRAG_IDX].len; 49 curr_idx = IP_LAST_FRAG_IDX; 50 51 payload_len = ofs + last_len; 52 53 while (ofs != first_len) { 54 55 prev = m; 56 57 for (i = n; i != IP_FIRST_FRAG_IDX && ofs != first_len; i--) { 58 59 /* previous fragment found. */ 60 if (fp->frags[i].ofs + fp->frags[i].len == ofs) { 61 62 RTE_ASSERT(curr_idx != i); 63 64 /* adjust start of the last fragment data. */ 65 rte_pktmbuf_adj(m, 66 (uint16_t)(m->l2_len + m->l3_len)); 67 rte_pktmbuf_chain(fp->frags[i].mb, m); 68 69 /* this mbuf should not be accessed directly */ 70 fp->frags[curr_idx].mb = NULL; 71 curr_idx = i; 72 73 /* update our last fragment and offset. */ 74 m = fp->frags[i].mb; 75 ofs = fp->frags[i].ofs; 76 } 77 } 78 79 /* error - hole in the packet. */ 80 if (m == prev) { 81 return NULL; 82 } 83 } 84 85 /* chain with the first fragment. */ 86 rte_pktmbuf_adj(m, (uint16_t)(m->l2_len + m->l3_len)); 87 rte_pktmbuf_chain(fp->frags[IP_FIRST_FRAG_IDX].mb, m); 88 fp->frags[curr_idx].mb = NULL; 89 m = fp->frags[IP_FIRST_FRAG_IDX].mb; 90 fp->frags[IP_FIRST_FRAG_IDX].mb = NULL; 91 92 /* update ipv6 header for the reassembled datagram */ 93 ip_hdr = rte_pktmbuf_mtod_offset(m, struct rte_ipv6_hdr *, m->l2_len); 94 95 ip_hdr->payload_len = rte_cpu_to_be_16(payload_len); 96 97 /* 98 * remove fragmentation header. note that per RFC2460, we need to update 99 * the last non-fragmentable header with the "next header" field to contain 100 * type of the first fragmentable header, but we currently don't support 101 * other headers, so we assume there are no other headers and thus update 102 * the main IPv6 header instead. 103 */ 104 move_len = m->l2_len + m->l3_len - sizeof(*frag_hdr); 105 frag_hdr = (struct ipv6_extension_fragment *) (ip_hdr + 1); 106 ip_hdr->proto = frag_hdr->next_header; 107 108 ip_frag_memmove(rte_pktmbuf_mtod_offset(m, char *, sizeof(*frag_hdr)), 109 rte_pktmbuf_mtod(m, char*), move_len); 110 111 rte_pktmbuf_adj(m, sizeof(*frag_hdr)); 112 113 return m; 114 } 115 116 /* 117 * Process new mbuf with fragment of IPV6 datagram. 118 * Incoming mbuf should have its l2_len/l3_len fields setup correctly. 119 * @param tbl 120 * Table where to lookup/add the fragmented packet. 121 * @param mb 122 * Incoming mbuf with IPV6 fragment. 123 * @param tms 124 * Fragment arrival timestamp. 125 * @param ip_hdr 126 * Pointer to the IPV6 header. 127 * @param frag_hdr 128 * Pointer to the IPV6 fragment extension header. 129 * @return 130 * Pointer to mbuf for reassembled packet, or NULL if: 131 * - an error occurred. 132 * - not all fragments of the packet are collected yet. 133 */ 134 #define MORE_FRAGS(x) (((x) & 0x100) >> 8) 135 #define FRAG_OFFSET(x) (rte_cpu_to_be_16(x) >> 3) 136 struct rte_mbuf * 137 rte_ipv6_frag_reassemble_packet(struct rte_ip_frag_tbl *tbl, 138 struct rte_ip_frag_death_row *dr, struct rte_mbuf *mb, uint64_t tms, 139 struct rte_ipv6_hdr *ip_hdr, struct ipv6_extension_fragment *frag_hdr) 140 { 141 struct ip_frag_pkt *fp; 142 struct ip_frag_key key; 143 uint16_t ip_ofs; 144 int32_t ip_len; 145 int32_t trim; 146 147 rte_memcpy(&key.src_dst[0], ip_hdr->src_addr, 16); 148 rte_memcpy(&key.src_dst[2], ip_hdr->dst_addr, 16); 149 150 key.id = frag_hdr->id; 151 key.key_len = IPV6_KEYLEN; 152 153 ip_ofs = FRAG_OFFSET(frag_hdr->frag_data) * 8; 154 155 /* 156 * as per RFC2460, payload length contains all extension headers 157 * as well. 158 * since we don't support anything but frag headers, 159 * this is what we remove from the payload len. 160 */ 161 ip_len = rte_be_to_cpu_16(ip_hdr->payload_len) - sizeof(*frag_hdr); 162 trim = mb->pkt_len - (ip_len + mb->l3_len + mb->l2_len); 163 164 IP_FRAG_LOG(DEBUG, "%s:%d:\n" 165 "mbuf: %p, tms: %" PRIu64 166 ", key: <" IPv6_KEY_BYTES_FMT ", %#x>, " 167 "ofs: %u, len: %d, padding: %d, flags: %#x\n" 168 "tbl: %p, max_cycles: %" PRIu64 ", entry_mask: %#x, " 169 "max_entries: %u, use_entries: %u\n\n", 170 __func__, __LINE__, 171 mb, tms, IPv6_KEY_BYTES(key.src_dst), key.id, ip_ofs, ip_len, 172 trim, RTE_IPV6_GET_MF(frag_hdr->frag_data), 173 tbl, tbl->max_cycles, tbl->entry_mask, tbl->max_entries, 174 tbl->use_entries); 175 176 /* check that fragment length is greater then zero. */ 177 if (ip_len <= 0) { 178 IP_FRAG_MBUF2DR(dr, mb); 179 return NULL; 180 } 181 182 if (unlikely(trim > 0)) 183 rte_pktmbuf_trim(mb, trim); 184 185 /* try to find/add entry into the fragment's table. */ 186 fp = ip_frag_find(tbl, dr, &key, tms); 187 if (fp == NULL) { 188 IP_FRAG_MBUF2DR(dr, mb); 189 return NULL; 190 } 191 192 IP_FRAG_LOG(DEBUG, "%s:%d:\n" 193 "tbl: %p, max_entries: %u, use_entries: %u\n" 194 "ipv6_frag_pkt: %p, key: <" IPv6_KEY_BYTES_FMT ", %#x>, start: %" PRIu64 195 ", total_size: %u, frag_size: %u, last_idx: %u\n\n", 196 __func__, __LINE__, 197 tbl, tbl->max_entries, tbl->use_entries, 198 fp, IPv6_KEY_BYTES(fp->key.src_dst), fp->key.id, fp->start, 199 fp->total_size, fp->frag_size, fp->last_idx); 200 201 202 /* process the fragmented packet. */ 203 mb = ip_frag_process(fp, dr, mb, ip_ofs, ip_len, 204 MORE_FRAGS(frag_hdr->frag_data)); 205 ip_frag_inuse(tbl, fp); 206 207 IP_FRAG_LOG(DEBUG, "%s:%d:\n" 208 "mbuf: %p\n" 209 "tbl: %p, max_entries: %u, use_entries: %u\n" 210 "ipv6_frag_pkt: %p, key: <" IPv6_KEY_BYTES_FMT ", %#x>, start: %" PRIu64 211 ", total_size: %u, frag_size: %u, last_idx: %u\n\n", 212 __func__, __LINE__, mb, 213 tbl, tbl->max_entries, tbl->use_entries, 214 fp, IPv6_KEY_BYTES(fp->key.src_dst), fp->key.id, fp->start, 215 fp->total_size, fp->frag_size, fp->last_idx); 216 217 return mb; 218 } 219