lib/librte_gro/gro_tcp4.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2017 Intel Corporation
   3  */
   4
   5 #include <rte_malloc.h>
   6 #include <rte_mbuf.h>
   7 #include <rte_cycles.h>
   8 #include <rte_ethdev.h>
   9 #include <rte_ip.h>
  10 #include <rte_tcp.h>
  11
  12 #include "gro_tcp4.h"
  13
  14 void *
  15 gro_tcp4_tbl_create(uint16_t socket_id,
  16                 uint16_t max_flow_num,
  17                 uint16_t max_item_per_flow)
  18 {
  19         struct gro_tcp4_tbl *tbl;
  20         size_t size;
  21         uint32_t entries_num, i;
  22
  23         entries_num = max_flow_num * max_item_per_flow;
  24         entries_num = RTE_MIN(entries_num, GRO_TCP4_TBL_MAX_ITEM_NUM);
  25
  26         if (entries_num == 0)
  27                 return NULL;
  28
  29         tbl = rte_zmalloc_socket(__func__,
  30                         sizeof(struct gro_tcp4_tbl),
  31                         RTE_CACHE_LINE_SIZE,
  32                         socket_id);
  33         if (tbl == NULL)
  34                 return NULL;
  35
  36         size = sizeof(struct gro_tcp4_item) * entries_num;
  37         tbl->items = rte_zmalloc_socket(__func__,
  38                         size,
  39                         RTE_CACHE_LINE_SIZE,
  40                         socket_id);
  41         if (tbl->items == NULL) {
  42                 rte_free(tbl);
  43                 return NULL;
  44         }
  45         tbl->max_item_num = entries_num;
  46
  47         size = sizeof(struct gro_tcp4_flow) * entries_num;
  48         tbl->flows = rte_zmalloc_socket(__func__,
  49                         size,
  50                         RTE_CACHE_LINE_SIZE,
  51                         socket_id);
  52         if (tbl->flows == NULL) {
  53                 rte_free(tbl->items);
  54                 rte_free(tbl);
  55                 return NULL;
  56         }
  57         /* INVALID_ARRAY_INDEX indicates an empty flow */
  58         for (i = 0; i < entries_num; i++)
  59                 tbl->flows[i].start_index = INVALID_ARRAY_INDEX;
  60         tbl->max_flow_num = entries_num;
  61
  62         return tbl;
  63 }
  64
  65 void
  66 gro_tcp4_tbl_destroy(void *tbl)
  67 {
  68         struct gro_tcp4_tbl *tcp_tbl = tbl;
  69
  70         if (tcp_tbl) {
  71                 rte_free(tcp_tbl->items);
  72                 rte_free(tcp_tbl->flows);
  73         }
  74         rte_free(tcp_tbl);
  75 }
  76
  77 /*
  78  * merge two TCP/IPv4 packets without updating checksums.
  79  * If cmp is larger than 0, append the new packet to the
  80  * original packet. Otherwise, pre-pend the new packet to
  81  * the original packet.
  82  */
  83 static inline int
  84 merge_two_tcp4_packets(struct gro_tcp4_item *item,
  85                 struct rte_mbuf *pkt,
  86                 int cmp,
  87                 uint32_t sent_seq,
  88                 uint16_t ip_id)
  89 {
  90         struct rte_mbuf *pkt_head, *pkt_tail, *lastseg;
  91         uint16_t hdr_len;
  92
  93         if (cmp > 0) {
  94                 pkt_head = item->firstseg;
  95                 pkt_tail = pkt;
  96         } else {
  97                 pkt_head = pkt;
  98                 pkt_tail = item->firstseg;
  99         }
 100
 101         /* check if the IPv4 packet length is greater than the max value */
 102         hdr_len = pkt_head->l2_len + pkt_head->l3_len + pkt_head->l4_len;
 103         if (unlikely(pkt_head->pkt_len - pkt_head->l2_len + pkt_tail->pkt_len -
 104                                 hdr_len > MAX_IPV4_PKT_LENGTH))
 105                 return 0;
 106
 107         /* remove the packet header for the tail packet */
 108         rte_pktmbuf_adj(pkt_tail, hdr_len);
 109
 110         /* chain two packets together */
 111         if (cmp > 0) {
 112                 item->lastseg->next = pkt;
 113                 item->lastseg = rte_pktmbuf_lastseg(pkt);
 114                 /* update IP ID to the larger value */
 115                 item->ip_id = ip_id;
 116         } else {
 117                 lastseg = rte_pktmbuf_lastseg(pkt);
 118                 lastseg->next = item->firstseg;
 119                 item->firstseg = pkt;
 120                 /* update sent_seq to the smaller value */
 121                 item->sent_seq = sent_seq;
 122         }
 123         item->nb_merged++;
 124
 125         /* update mbuf metadata for the merged packet */
 126         pkt_head->nb_segs += pkt_tail->nb_segs;
 127         pkt_head->pkt_len += pkt_tail->pkt_len;
 128
 129         return 1;
 130 }
 131
 132 /*
 133  * Check if two TCP/IPv4 packets are neighbors.
 134  */
 135 static inline int
 136 check_seq_option(struct gro_tcp4_item *item,
 137                 struct tcp_hdr *tcph,
 138                 uint32_t sent_seq,
 139                 uint16_t ip_id,
 140                 uint16_t tcp_hl,
 141                 uint16_t tcp_dl)
 142 {
 143         struct rte_mbuf *pkt_orig = item->firstseg;
 144         struct ipv4_hdr *iph_orig;
 145         struct tcp_hdr *tcph_orig;
 146         uint16_t len, tcp_hl_orig;
 147
 148         iph_orig = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt_orig, char *) +
 149                         pkt_orig->l2_len);
 150         tcph_orig = (struct tcp_hdr *)((char *)iph_orig + pkt_orig->l3_len);
 151         tcp_hl_orig = pkt_orig->l4_len;
 152
 153         /* Check if TCP option fields equal */
 154         len = RTE_MAX(tcp_hl, tcp_hl_orig) - sizeof(struct tcp_hdr);
 155         if ((tcp_hl != tcp_hl_orig) ||
 156                         ((len > 0) && (memcmp(tcph + 1, tcph_orig + 1,
 157                                         len) != 0)))
 158                 return 0;
 159
 160         /* check if the two packets are neighbors */
 161         len = pkt_orig->pkt_len - pkt_orig->l2_len - pkt_orig->l3_len -
 162                 tcp_hl_orig;
 163         if ((sent_seq == item->sent_seq + len) && (ip_id == item->ip_id + 1))
 164                 /* append the new packet */
 165                 return 1;
 166         else if ((sent_seq + tcp_dl == item->sent_seq) &&
 167                         (ip_id + item->nb_merged == item->ip_id))
 168                 /* pre-pend the new packet */
 169                 return -1;
 170
 171         return 0;
 172 }
 173
 174 static inline uint32_t
 175 find_an_empty_item(struct gro_tcp4_tbl *tbl)
 176 {
 177         uint32_t i;
 178         uint32_t max_item_num = tbl->max_item_num;
 179
 180         for (i = 0; i < max_item_num; i++)
 181                 if (tbl->items[i].firstseg == NULL)
 182                         return i;
 183         return INVALID_ARRAY_INDEX;
 184 }
 185
 186 static inline uint32_t
 187 find_an_empty_flow(struct gro_tcp4_tbl *tbl)
 188 {
 189         uint32_t i;
 190         uint32_t max_flow_num = tbl->max_flow_num;
 191
 192         for (i = 0; i < max_flow_num; i++)
 193                 if (tbl->flows[i].start_index == INVALID_ARRAY_INDEX)
 194                         return i;
 195         return INVALID_ARRAY_INDEX;
 196 }
 197
 198 static inline uint32_t
 199 insert_new_item(struct gro_tcp4_tbl *tbl,
 200                 struct rte_mbuf *pkt,
 201                 uint64_t start_time,
 202                 uint32_t prev_idx,
 203                 uint32_t sent_seq,
 204                 uint16_t ip_id)
 205 {
 206         uint32_t item_idx;
 207
 208         item_idx = find_an_empty_item(tbl);
 209         if (item_idx == INVALID_ARRAY_INDEX)
 210                 return INVALID_ARRAY_INDEX;
 211
 212         tbl->items[item_idx].firstseg = pkt;
 213         tbl->items[item_idx].lastseg = rte_pktmbuf_lastseg(pkt);
 214         tbl->items[item_idx].start_time = start_time;
 215         tbl->items[item_idx].next_pkt_idx = INVALID_ARRAY_INDEX;
 216         tbl->items[item_idx].sent_seq = sent_seq;
 217         tbl->items[item_idx].ip_id = ip_id;
 218         tbl->items[item_idx].nb_merged = 1;
 219         tbl->item_num++;
 220
 221         /* if the previous packet exists, chain them together. */
 222         if (prev_idx != INVALID_ARRAY_INDEX) {
 223                 tbl->items[item_idx].next_pkt_idx =
 224                         tbl->items[prev_idx].next_pkt_idx;
 225                 tbl->items[prev_idx].next_pkt_idx = item_idx;
 226         }
 227
 228         return item_idx;
 229 }
 230
 231 static inline uint32_t
 232 delete_item(struct gro_tcp4_tbl *tbl, uint32_t item_idx,
 233                 uint32_t prev_item_idx)
 234 {
 235         uint32_t next_idx = tbl->items[item_idx].next_pkt_idx;
 236
 237         /* NULL indicates an empty item */
 238         tbl->items[item_idx].firstseg = NULL;
 239         tbl->item_num--;
 240         if (prev_item_idx != INVALID_ARRAY_INDEX)
 241                 tbl->items[prev_item_idx].next_pkt_idx = next_idx;
 242
 243         return next_idx;
 244 }
 245
 246 static inline uint32_t
 247 insert_new_flow(struct gro_tcp4_tbl *tbl,
 248                 struct tcp4_flow_key *src,
 249                 uint32_t item_idx)
 250 {
 251         struct tcp4_flow_key *dst;
 252         uint32_t flow_idx;
 253
 254         flow_idx = find_an_empty_flow(tbl);
 255         if (unlikely(flow_idx == INVALID_ARRAY_INDEX))
 256                 return INVALID_ARRAY_INDEX;
 257
 258         dst = &(tbl->flows[flow_idx].key);
 259
 260         ether_addr_copy(&(src->eth_saddr), &(dst->eth_saddr));
 261         ether_addr_copy(&(src->eth_daddr), &(dst->eth_daddr));
 262         dst->ip_src_addr = src->ip_src_addr;
 263         dst->ip_dst_addr = src->ip_dst_addr;
 264         dst->recv_ack = src->recv_ack;
 265         dst->src_port = src->src_port;
 266         dst->dst_port = src->dst_port;
 267
 268         tbl->flows[flow_idx].start_index = item_idx;
 269         tbl->flow_num++;
 270
 271         return flow_idx;
 272 }
 273
 274 /*
 275  * Check if two TCP/IPv4 packets belong to the same flow.
 276  */
 277 static inline int
 278 is_same_tcp4_flow(struct tcp4_flow_key k1, struct tcp4_flow_key k2)
 279 {
 280         return (is_same_ether_addr(&k1.eth_saddr, &k2.eth_saddr) &&
 281                         is_same_ether_addr(&k1.eth_daddr, &k2.eth_daddr) &&
 282                         (k1.ip_src_addr == k2.ip_src_addr) &&
 283                         (k1.ip_dst_addr == k2.ip_dst_addr) &&
 284                         (k1.recv_ack == k2.recv_ack) &&
 285                         (k1.src_port == k2.src_port) &&
 286                         (k1.dst_port == k2.dst_port));
 287 }
 288
 289 /*
 290  * update the packet length for the flushed packet.
 291  */
 292 static inline void
 293 update_header(struct gro_tcp4_item *item)
 294 {
 295         struct ipv4_hdr *ipv4_hdr;
 296         struct rte_mbuf *pkt = item->firstseg;
 297
 298         ipv4_hdr = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
 299                         pkt->l2_len);
 300         ipv4_hdr->total_length = rte_cpu_to_be_16(pkt->pkt_len -
 301                         pkt->l2_len);
 302 }
 303
 304 int32_t
 305 gro_tcp4_reassemble(struct rte_mbuf *pkt,
 306                 struct gro_tcp4_tbl *tbl,
 307                 uint64_t start_time)
 308 {
 309         struct ether_hdr *eth_hdr;
 310         struct ipv4_hdr *ipv4_hdr;
 311         struct tcp_hdr *tcp_hdr;
 312         uint32_t sent_seq;
 313         uint16_t tcp_dl, ip_id, hdr_len;
 314
 315         struct tcp4_flow_key key;
 316         uint32_t cur_idx, prev_idx, item_idx;
 317         uint32_t i, max_flow_num, remaining_flow_num;
 318         int cmp;
 319         uint8_t find;
 320
 321         eth_hdr = rte_pktmbuf_mtod(pkt, struct ether_hdr *);
 322         ipv4_hdr = (struct ipv4_hdr *)((char *)eth_hdr + pkt->l2_len);
 323         tcp_hdr = (struct tcp_hdr *)((char *)ipv4_hdr + pkt->l3_len);
 324         hdr_len = pkt->l2_len + pkt->l3_len + pkt->l4_len;
 325
 326         /*
 327          * Don't process the packet which has FIN, SYN, RST, PSH, URG, ECE
 328          * or CWR set.
 329          */
 330         if (tcp_hdr->tcp_flags != TCP_ACK_FLAG)
 331                 return -1;
 332         /*
 333          * Don't process the packet whose payload length is less than or
 334          * equal to 0.
 335          */
 336         tcp_dl = pkt->pkt_len - hdr_len;
 337         if (tcp_dl <= 0)
 338                 return -1;
 339
 340         ip_id = rte_be_to_cpu_16(ipv4_hdr->packet_id);
 341         sent_seq = rte_be_to_cpu_32(tcp_hdr->sent_seq);
 342
 343         ether_addr_copy(&(eth_hdr->s_addr), &(key.eth_saddr));
 344         ether_addr_copy(&(eth_hdr->d_addr), &(key.eth_daddr));
 345         key.ip_src_addr = ipv4_hdr->src_addr;
 346         key.ip_dst_addr = ipv4_hdr->dst_addr;
 347         key.src_port = tcp_hdr->src_port;
 348         key.dst_port = tcp_hdr->dst_port;
 349         key.recv_ack = tcp_hdr->recv_ack;
 350
 351         /* Search for a matched flow. */
 352         max_flow_num = tbl->max_flow_num;
 353         remaining_flow_num = tbl->flow_num;
 354         find = 0;
 355         for (i = 0; i < max_flow_num && remaining_flow_num; i++) {
 356                 if (tbl->flows[i].start_index != INVALID_ARRAY_INDEX) {
 357                         if (is_same_tcp4_flow(tbl->flows[i].key, key)) {
 358                                 find = 1;
 359                                 break;
 360                         }
 361                         remaining_flow_num--;
 362                 }
 363         }
 364
 365         /*
 366          * Fail to find a matched flow. Insert a new flow and store the
 367          * packet into the flow.
 368          */
 369         if (find == 0) {
 370                 item_idx = insert_new_item(tbl, pkt, start_time,
 371                                 INVALID_ARRAY_INDEX, sent_seq, ip_id);
 372                 if (item_idx == INVALID_ARRAY_INDEX)
 373                         return -1;
 374                 if (insert_new_flow(tbl, &key, item_idx) ==
 375                                 INVALID_ARRAY_INDEX) {
 376                         /*
 377                          * Fail to insert a new flow, so delete the
 378                          * stored packet.
 379                          */
 380                         delete_item(tbl, item_idx, INVALID_ARRAY_INDEX);
 381                         return -1;
 382                 }
 383                 return 0;
 384         }
 385
 386         /*
 387          * Check all packets in the flow and try to find a neighbor for
 388          * the input packet.
 389          */
 390         cur_idx = tbl->flows[i].start_index;
 391         prev_idx = cur_idx;
 392         do {
 393                 cmp = check_seq_option(&(tbl->items[cur_idx]), tcp_hdr,
 394                                 sent_seq, ip_id, pkt->l4_len, tcp_dl);
 395                 if (cmp) {
 396                         if (merge_two_tcp4_packets(&(tbl->items[cur_idx]),
 397                                                 pkt, cmp, sent_seq, ip_id))
 398                                 return 1;
 399                         /*
 400                          * Fail to merge the two packets, as the packet
 401                          * length is greater than the max value. Store
 402                          * the packet into the flow.
 403                          */
 404                         if (insert_new_item(tbl, pkt, start_time, prev_idx,
 405                                                 sent_seq, ip_id) ==
 406                                         INVALID_ARRAY_INDEX)
 407                                 return -1;
 408                         return 0;
 409                 }
 410                 prev_idx = cur_idx;
 411                 cur_idx = tbl->items[cur_idx].next_pkt_idx;
 412         } while (cur_idx != INVALID_ARRAY_INDEX);
 413
 414         /* Fail to find a neighbor, so store the packet into the flow. */
 415         if (insert_new_item(tbl, pkt, start_time, prev_idx, sent_seq,
 416                                 ip_id) == INVALID_ARRAY_INDEX)
 417                 return -1;
 418
 419         return 0;
 420 }
 421
 422 uint16_t
 423 gro_tcp4_tbl_timeout_flush(struct gro_tcp4_tbl *tbl,
 424                 uint64_t flush_timestamp,
 425                 struct rte_mbuf **out,
 426                 uint16_t nb_out)
 427 {
 428         uint16_t k = 0;
 429         uint32_t i, j;
 430         uint32_t max_flow_num = tbl->max_flow_num;
 431
 432         for (i = 0; i < max_flow_num; i++) {
 433                 if (unlikely(tbl->flow_num == 0))
 434                         return k;
 435
 436                 j = tbl->flows[i].start_index;
 437                 while (j != INVALID_ARRAY_INDEX) {
 438                         if (tbl->items[j].start_time <= flush_timestamp) {
 439                                 out[k++] = tbl->items[j].firstseg;
 440                                 if (tbl->items[j].nb_merged > 1)
 441                                         update_header(&(tbl->items[j]));
 442                                 /*
 443                                  * Delete the packet and get the next
 444                                  * packet in the flow.
 445                                  */
 446                                 j = delete_item(tbl, j, INVALID_ARRAY_INDEX);
 447                                 tbl->flows[i].start_index = j;
 448                                 if (j == INVALID_ARRAY_INDEX)
 449                                         tbl->flow_num--;
 450
 451                                 if (unlikely(k == nb_out))
 452                                         return k;
 453                         } else
 454                                 /*
 455                                  * The left packets in this flow won't be
 456                                  * timeout. Go to check other flows.
 457                                  */
 458                                 break;
 459                 }
 460         }
 461         return k;
 462 }
 463
 464 uint32_t
 465 gro_tcp4_tbl_pkt_count(void *tbl)
 466 {
 467         struct gro_tcp4_tbl *gro_tbl = tbl;
 468
 469         if (gro_tbl)
 470                 return gro_tbl->item_num;
 471
 472         return 0;
 473 }