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                 uint8_t is_atomic)
 143 {
 144         struct rte_mbuf *pkt_orig = item->firstseg;
 145         struct ipv4_hdr *iph_orig;
 146         struct tcp_hdr *tcph_orig;
 147         uint16_t len, tcp_hl_orig;
 148
 149         iph_orig = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt_orig, char *) +
 150                         pkt_orig->l2_len);
 151         tcph_orig = (struct tcp_hdr *)((char *)iph_orig + pkt_orig->l3_len);
 152         tcp_hl_orig = pkt_orig->l4_len;
 153
 154         /* Check if TCP option fields equal */
 155         len = RTE_MAX(tcp_hl, tcp_hl_orig) - sizeof(struct tcp_hdr);
 156         if ((tcp_hl != tcp_hl_orig) ||
 157                         ((len > 0) && (memcmp(tcph + 1, tcph_orig + 1,
 158                                         len) != 0)))
 159                 return 0;
 160
 161         /* Don't merge packets whose DF bits are different */
 162         if (unlikely(item->is_atomic ^ is_atomic))
 163                 return 0;
 164
 165         /* check if the two packets are neighbors */
 166         len = pkt_orig->pkt_len - pkt_orig->l2_len - pkt_orig->l3_len -
 167                 tcp_hl_orig;
 168         if ((sent_seq == item->sent_seq + len) && (is_atomic ||
 169                                 (ip_id == item->ip_id + 1)))
 170                 /* append the new packet */
 171                 return 1;
 172         else if ((sent_seq + tcp_dl == item->sent_seq) && (is_atomic ||
 173                         (ip_id + item->nb_merged == item->ip_id)))
 174                 /* pre-pend the new packet */
 175                 return -1;
 176
 177         return 0;
 178 }
 179
 180 static inline uint32_t
 181 find_an_empty_item(struct gro_tcp4_tbl *tbl)
 182 {
 183         uint32_t i;
 184         uint32_t max_item_num = tbl->max_item_num;
 185
 186         for (i = 0; i < max_item_num; i++)
 187                 if (tbl->items[i].firstseg == NULL)
 188                         return i;
 189         return INVALID_ARRAY_INDEX;
 190 }
 191
 192 static inline uint32_t
 193 find_an_empty_flow(struct gro_tcp4_tbl *tbl)
 194 {
 195         uint32_t i;
 196         uint32_t max_flow_num = tbl->max_flow_num;
 197
 198         for (i = 0; i < max_flow_num; i++)
 199                 if (tbl->flows[i].start_index == INVALID_ARRAY_INDEX)
 200                         return i;
 201         return INVALID_ARRAY_INDEX;
 202 }
 203
 204 static inline uint32_t
 205 insert_new_item(struct gro_tcp4_tbl *tbl,
 206                 struct rte_mbuf *pkt,
 207                 uint64_t start_time,
 208                 uint32_t prev_idx,
 209                 uint32_t sent_seq,
 210                 uint16_t ip_id,
 211                 uint8_t is_atomic)
 212 {
 213         uint32_t item_idx;
 214
 215         item_idx = find_an_empty_item(tbl);
 216         if (item_idx == INVALID_ARRAY_INDEX)
 217                 return INVALID_ARRAY_INDEX;
 218
 219         tbl->items[item_idx].firstseg = pkt;
 220         tbl->items[item_idx].lastseg = rte_pktmbuf_lastseg(pkt);
 221         tbl->items[item_idx].start_time = start_time;
 222         tbl->items[item_idx].next_pkt_idx = INVALID_ARRAY_INDEX;
 223         tbl->items[item_idx].sent_seq = sent_seq;
 224         tbl->items[item_idx].ip_id = ip_id;
 225         tbl->items[item_idx].nb_merged = 1;
 226         tbl->items[item_idx].is_atomic = is_atomic;
 227         tbl->item_num++;
 228
 229         /* if the previous packet exists, chain them together. */
 230         if (prev_idx != INVALID_ARRAY_INDEX) {
 231                 tbl->items[item_idx].next_pkt_idx =
 232                         tbl->items[prev_idx].next_pkt_idx;
 233                 tbl->items[prev_idx].next_pkt_idx = item_idx;
 234         }
 235
 236         return item_idx;
 237 }
 238
 239 static inline uint32_t
 240 delete_item(struct gro_tcp4_tbl *tbl, uint32_t item_idx,
 241                 uint32_t prev_item_idx)
 242 {
 243         uint32_t next_idx = tbl->items[item_idx].next_pkt_idx;
 244
 245         /* NULL indicates an empty item */
 246         tbl->items[item_idx].firstseg = NULL;
 247         tbl->item_num--;
 248         if (prev_item_idx != INVALID_ARRAY_INDEX)
 249                 tbl->items[prev_item_idx].next_pkt_idx = next_idx;
 250
 251         return next_idx;
 252 }
 253
 254 static inline uint32_t
 255 insert_new_flow(struct gro_tcp4_tbl *tbl,
 256                 struct tcp4_flow_key *src,
 257                 uint32_t item_idx)
 258 {
 259         struct tcp4_flow_key *dst;
 260         uint32_t flow_idx;
 261
 262         flow_idx = find_an_empty_flow(tbl);
 263         if (unlikely(flow_idx == INVALID_ARRAY_INDEX))
 264                 return INVALID_ARRAY_INDEX;
 265
 266         dst = &(tbl->flows[flow_idx].key);
 267
 268         ether_addr_copy(&(src->eth_saddr), &(dst->eth_saddr));
 269         ether_addr_copy(&(src->eth_daddr), &(dst->eth_daddr));
 270         dst->ip_src_addr = src->ip_src_addr;
 271         dst->ip_dst_addr = src->ip_dst_addr;
 272         dst->recv_ack = src->recv_ack;
 273         dst->src_port = src->src_port;
 274         dst->dst_port = src->dst_port;
 275
 276         tbl->flows[flow_idx].start_index = item_idx;
 277         tbl->flow_num++;
 278
 279         return flow_idx;
 280 }
 281
 282 /*
 283  * Check if two TCP/IPv4 packets belong to the same flow.
 284  */
 285 static inline int
 286 is_same_tcp4_flow(struct tcp4_flow_key k1, struct tcp4_flow_key k2)
 287 {
 288         return (is_same_ether_addr(&k1.eth_saddr, &k2.eth_saddr) &&
 289                         is_same_ether_addr(&k1.eth_daddr, &k2.eth_daddr) &&
 290                         (k1.ip_src_addr == k2.ip_src_addr) &&
 291                         (k1.ip_dst_addr == k2.ip_dst_addr) &&
 292                         (k1.recv_ack == k2.recv_ack) &&
 293                         (k1.src_port == k2.src_port) &&
 294                         (k1.dst_port == k2.dst_port));
 295 }
 296
 297 /*
 298  * update the packet length for the flushed packet.
 299  */
 300 static inline void
 301 update_header(struct gro_tcp4_item *item)
 302 {
 303         struct ipv4_hdr *ipv4_hdr;
 304         struct rte_mbuf *pkt = item->firstseg;
 305
 306         ipv4_hdr = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
 307                         pkt->l2_len);
 308         ipv4_hdr->total_length = rte_cpu_to_be_16(pkt->pkt_len -
 309                         pkt->l2_len);
 310 }
 311
 312 int32_t
 313 gro_tcp4_reassemble(struct rte_mbuf *pkt,
 314                 struct gro_tcp4_tbl *tbl,
 315                 uint64_t start_time)
 316 {
 317         struct ether_hdr *eth_hdr;
 318         struct ipv4_hdr *ipv4_hdr;
 319         struct tcp_hdr *tcp_hdr;
 320         uint32_t sent_seq;
 321         uint16_t tcp_dl, ip_id, hdr_len, frag_off;
 322         uint8_t is_atomic;
 323
 324         struct tcp4_flow_key key;
 325         uint32_t cur_idx, prev_idx, item_idx;
 326         uint32_t i, max_flow_num, remaining_flow_num;
 327         int cmp;
 328         uint8_t find;
 329
 330         eth_hdr = rte_pktmbuf_mtod(pkt, struct ether_hdr *);
 331         ipv4_hdr = (struct ipv4_hdr *)((char *)eth_hdr + pkt->l2_len);
 332         tcp_hdr = (struct tcp_hdr *)((char *)ipv4_hdr + pkt->l3_len);
 333         hdr_len = pkt->l2_len + pkt->l3_len + pkt->l4_len;
 334
 335         /*
 336          * Don't process the packet which has FIN, SYN, RST, PSH, URG, ECE
 337          * or CWR set.
 338          */
 339         if (tcp_hdr->tcp_flags != TCP_ACK_FLAG)
 340                 return -1;
 341         /*
 342          * Don't process the packet whose payload length is less than or
 343          * equal to 0.
 344          */
 345         tcp_dl = pkt->pkt_len - hdr_len;
 346         if (tcp_dl <= 0)
 347                 return -1;
 348
 349         /*
 350          * Save IPv4 ID for the packet whose DF bit is 0. For the packet
 351          * whose DF bit is 1, IPv4 ID is ignored.
 352          */
 353         frag_off = rte_be_to_cpu_16(ipv4_hdr->fragment_offset);
 354         is_atomic = (frag_off & IPV4_HDR_DF_FLAG) == IPV4_HDR_DF_FLAG;
 355         ip_id = is_atomic ? 0 : rte_be_to_cpu_16(ipv4_hdr->packet_id);
 356         sent_seq = rte_be_to_cpu_32(tcp_hdr->sent_seq);
 357
 358         ether_addr_copy(&(eth_hdr->s_addr), &(key.eth_saddr));
 359         ether_addr_copy(&(eth_hdr->d_addr), &(key.eth_daddr));
 360         key.ip_src_addr = ipv4_hdr->src_addr;
 361         key.ip_dst_addr = ipv4_hdr->dst_addr;
 362         key.src_port = tcp_hdr->src_port;
 363         key.dst_port = tcp_hdr->dst_port;
 364         key.recv_ack = tcp_hdr->recv_ack;
 365
 366         /* Search for a matched flow. */
 367         max_flow_num = tbl->max_flow_num;
 368         remaining_flow_num = tbl->flow_num;
 369         find = 0;
 370         for (i = 0; i < max_flow_num && remaining_flow_num; i++) {
 371                 if (tbl->flows[i].start_index != INVALID_ARRAY_INDEX) {
 372                         if (is_same_tcp4_flow(tbl->flows[i].key, key)) {
 373                                 find = 1;
 374                                 break;
 375                         }
 376                         remaining_flow_num--;
 377                 }
 378         }
 379
 380         /*
 381          * Fail to find a matched flow. Insert a new flow and store the
 382          * packet into the flow.
 383          */
 384         if (find == 0) {
 385                 item_idx = insert_new_item(tbl, pkt, start_time,
 386                                 INVALID_ARRAY_INDEX, sent_seq, ip_id,
 387                                 is_atomic);
 388                 if (item_idx == INVALID_ARRAY_INDEX)
 389                         return -1;
 390                 if (insert_new_flow(tbl, &key, item_idx) ==
 391                                 INVALID_ARRAY_INDEX) {
 392                         /*
 393                          * Fail to insert a new flow, so delete the
 394                          * stored packet.
 395                          */
 396                         delete_item(tbl, item_idx, INVALID_ARRAY_INDEX);
 397                         return -1;
 398                 }
 399                 return 0;
 400         }
 401
 402         /*
 403          * Check all packets in the flow and try to find a neighbor for
 404          * the input packet.
 405          */
 406         cur_idx = tbl->flows[i].start_index;
 407         prev_idx = cur_idx;
 408         do {
 409                 cmp = check_seq_option(&(tbl->items[cur_idx]), tcp_hdr,
 410                                 sent_seq, ip_id, pkt->l4_len, tcp_dl,
 411                                 is_atomic);
 412                 if (cmp) {
 413                         if (merge_two_tcp4_packets(&(tbl->items[cur_idx]),
 414                                                 pkt, cmp, sent_seq, ip_id))
 415                                 return 1;
 416                         /*
 417                          * Fail to merge the two packets, as the packet
 418                          * length is greater than the max value. Store
 419                          * the packet into the flow.
 420                          */
 421                         if (insert_new_item(tbl, pkt, start_time, prev_idx,
 422                                                 sent_seq, ip_id, is_atomic) ==
 423                                         INVALID_ARRAY_INDEX)
 424                                 return -1;
 425                         return 0;
 426                 }
 427                 prev_idx = cur_idx;
 428                 cur_idx = tbl->items[cur_idx].next_pkt_idx;
 429         } while (cur_idx != INVALID_ARRAY_INDEX);
 430
 431         /* Fail to find a neighbor, so store the packet into the flow. */
 432         if (insert_new_item(tbl, pkt, start_time, prev_idx, sent_seq,
 433                                 ip_id, is_atomic) == INVALID_ARRAY_INDEX)
 434                 return -1;
 435
 436         return 0;
 437 }
 438
 439 uint16_t
 440 gro_tcp4_tbl_timeout_flush(struct gro_tcp4_tbl *tbl,
 441                 uint64_t flush_timestamp,
 442                 struct rte_mbuf **out,
 443                 uint16_t nb_out)
 444 {
 445         uint16_t k = 0;
 446         uint32_t i, j;
 447         uint32_t max_flow_num = tbl->max_flow_num;
 448
 449         for (i = 0; i < max_flow_num; i++) {
 450                 if (unlikely(tbl->flow_num == 0))
 451                         return k;
 452
 453                 j = tbl->flows[i].start_index;
 454                 while (j != INVALID_ARRAY_INDEX) {
 455                         if (tbl->items[j].start_time <= flush_timestamp) {
 456                                 out[k++] = tbl->items[j].firstseg;
 457                                 if (tbl->items[j].nb_merged > 1)
 458                                         update_header(&(tbl->items[j]));
 459                                 /*
 460                                  * Delete the packet and get the next
 461                                  * packet in the flow.
 462                                  */
 463                                 j = delete_item(tbl, j, INVALID_ARRAY_INDEX);
 464                                 tbl->flows[i].start_index = j;
 465                                 if (j == INVALID_ARRAY_INDEX)
 466                                         tbl->flow_num--;
 467
 468                                 if (unlikely(k == nb_out))
 469                                         return k;
 470                         } else
 471                                 /*
 472                                  * The left packets in this flow won't be
 473                                  * timeout. Go to check other flows.
 474                                  */
 475                                 break;
 476                 }
 477         }
 478         return k;
 479 }
 480
 481 uint32_t
 482 gro_tcp4_tbl_pkt_count(void *tbl)
 483 {
 484         struct gro_tcp4_tbl *gro_tbl = tbl;
 485
 486         if (gro_tbl)
 487                 return gro_tbl->item_num;
 488
 489         return 0;
 490 }