sys/dev/netmap/netmap_offloadings.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause
   3  *
   4  * Copyright (C) 2014-2015 Vincenzo Maffione
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *   1. Redistributions of source code must retain the above copyright
  11  *      notice, this list of conditions and the following disclaimer.
  12  *   2. Redistributions in binary form must reproduce the above copyright
  13  *      notice, this list of conditions and the following disclaimer in the
  14  *      documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29
  30 #if defined(__FreeBSD__)
  31 #include <sys/cdefs.h> /* prerequisite */
  32
  33 #include <sys/types.h>
  34 #include <sys/errno.h>
  35 #include <sys/param.h>  /* defines used in kernel.h */
  36 #include <sys/kernel.h> /* types used in module initialization */
  37 #include <sys/sockio.h>
  38 #include <sys/malloc.h>
  39 #include <sys/socketvar.h>      /* struct socket */
  40 #include <sys/socket.h> /* sockaddrs */
  41 #include <net/if.h>
  42 #include <net/if_var.h>
  43 #include <machine/bus.h>        /* bus_dmamap_* */
  44 #include <sys/endian.h>
  45
  46 #elif defined(linux)
  47
  48 #include "bsd_glue.h"
  49
  50 #elif defined(__APPLE__)
  51
  52 #warning OSX support is only partial
  53 #include "osx_glue.h"
  54
  55 #else
  56
  57 #error  Unsupported platform
  58
  59 #endif /* unsupported */
  60
  61 #include <net/netmap.h>
  62 #include <dev/netmap/netmap_kern.h>
  63
  64
  65
  66 /* This routine is called by bdg_mismatch_datapath() when it finishes
  67  * accumulating bytes for a segment, in order to fix some fields in the
  68  * segment headers (which still contain the same content as the header
  69  * of the original GSO packet). 'pkt' points to the beginning of the IP
  70  * header of the segment, while 'len' is the length of the IP packet.
  71  */
  72 static void
  73 gso_fix_segment(uint8_t *pkt, size_t len, u_int ipv4, u_int iphlen, u_int tcp,
  74                 u_int idx, u_int segmented_bytes, u_int last_segment)
  75 {
  76         struct nm_iphdr *iph = (struct nm_iphdr *)(pkt);
  77         struct nm_ipv6hdr *ip6h = (struct nm_ipv6hdr *)(pkt);
  78         uint16_t *check = NULL;
  79         uint8_t *check_data = NULL;
  80
  81         if (ipv4) {
  82                 /* Set the IPv4 "Total Length" field. */
  83                 iph->tot_len = htobe16(len);
  84                 nm_prdis("ip total length %u", be16toh(ip->tot_len));
  85
  86                 /* Set the IPv4 "Identification" field. */
  87                 iph->id = htobe16(be16toh(iph->id) + idx);
  88                 nm_prdis("ip identification %u", be16toh(iph->id));
  89
  90                 /* Compute and insert the IPv4 header checksum. */
  91                 iph->check = 0;
  92                 iph->check = nm_os_csum_ipv4(iph);
  93                 nm_prdis("IP csum %x", be16toh(iph->check));
  94         } else {
  95                 /* Set the IPv6 "Payload Len" field. */
  96                 ip6h->payload_len = htobe16(len-iphlen);
  97         }
  98
  99         if (tcp) {
 100                 struct nm_tcphdr *tcph = (struct nm_tcphdr *)(pkt + iphlen);
 101
 102                 /* Set the TCP sequence number. */
 103                 tcph->seq = htobe32(be32toh(tcph->seq) + segmented_bytes);
 104                 nm_prdis("tcp seq %u", be32toh(tcph->seq));
 105
 106                 /* Zero the PSH and FIN TCP flags if this is not the last
 107                    segment. */
 108                 if (!last_segment)
 109                         tcph->flags &= ~(0x8 | 0x1);
 110                 nm_prdis("last_segment %u", last_segment);
 111
 112                 check = &tcph->check;
 113                 check_data = (uint8_t *)tcph;
 114         } else { /* UDP */
 115                 struct nm_udphdr *udph = (struct nm_udphdr *)(pkt + iphlen);
 116
 117                 /* Set the UDP 'Length' field. */
 118                 udph->len = htobe16(len-iphlen);
 119
 120                 check = &udph->check;
 121                 check_data = (uint8_t *)udph;
 122         }
 123
 124         /* Compute and insert TCP/UDP checksum. */
 125         *check = 0;
 126         if (ipv4)
 127                 nm_os_csum_tcpudp_ipv4(iph, check_data, len-iphlen, check);
 128         else
 129                 nm_os_csum_tcpudp_ipv6(ip6h, check_data, len-iphlen, check);
 130
 131         nm_prdis("TCP/UDP csum %x", be16toh(*check));
 132 }
 133
 134 static inline int
 135 vnet_hdr_is_bad(struct nm_vnet_hdr *vh)
 136 {
 137         uint8_t gso_type = vh->gso_type & ~VIRTIO_NET_HDR_GSO_ECN;
 138
 139         return (
 140                 (gso_type != VIRTIO_NET_HDR_GSO_NONE &&
 141                  gso_type != VIRTIO_NET_HDR_GSO_TCPV4 &&
 142                  gso_type != VIRTIO_NET_HDR_GSO_UDP &&
 143                  gso_type != VIRTIO_NET_HDR_GSO_TCPV6)
 144                 ||
 145                  (vh->flags & ~(VIRTIO_NET_HDR_F_NEEDS_CSUM
 146                                | VIRTIO_NET_HDR_F_DATA_VALID))
 147                );
 148 }
 149
 150 /* The VALE mismatch datapath implementation. */
 151 void
 152 bdg_mismatch_datapath(struct netmap_vp_adapter *na,
 153                       struct netmap_vp_adapter *dst_na,
 154                       const struct nm_bdg_fwd *ft_p,
 155                       struct netmap_ring *dst_ring,
 156                       u_int *j, u_int lim, u_int *howmany)
 157 {
 158         struct netmap_slot *dst_slot = NULL;
 159         struct nm_vnet_hdr *vh = NULL;
 160         const struct nm_bdg_fwd *ft_end = ft_p + ft_p->ft_frags;
 161
 162         /* Source and destination pointers. */
 163         uint8_t *dst, *src;
 164         size_t src_len, dst_len;
 165
 166         /* Indices and counters for the destination ring. */
 167         u_int j_start = *j;
 168         u_int j_cur = j_start;
 169         u_int dst_slots = 0;
 170
 171         if (unlikely(ft_p == ft_end)) {
 172                 nm_prlim(1, "No source slots to process");
 173                 return;
 174         }
 175
 176         /* Init source and dest pointers. */
 177         src = ft_p->ft_buf;
 178         src_len = ft_p->ft_len;
 179         dst_slot = &dst_ring->slot[j_cur];
 180         dst = NMB(&dst_na->up, dst_slot);
 181         dst_len = src_len;
 182
 183         /* If the source port uses the offloadings, while destination doesn't,
 184          * we grab the source virtio-net header and do the offloadings here.
 185          */
 186         if (na->up.virt_hdr_len && !dst_na->up.virt_hdr_len) {
 187                 vh = (struct nm_vnet_hdr *)src;
 188                 /* Initial sanity check on the source virtio-net header. If
 189                  * something seems wrong, just drop the packet. */
 190                 if (src_len < na->up.virt_hdr_len) {
 191                         nm_prlim(1, "Short src vnet header, dropping");
 192                         return;
 193                 }
 194                 if (unlikely(vnet_hdr_is_bad(vh))) {
 195                         nm_prlim(1, "Bad src vnet header, dropping");
 196                         return;
 197                 }
 198         }
 199
 200         /* We are processing the first input slot and there is a mismatch
 201          * between source and destination virt_hdr_len (SHL and DHL).
 202          * When the a client is using virtio-net headers, the header length
 203          * can be:
 204          *    - 10: the header corresponds to the struct nm_vnet_hdr
 205          *    - 12: the first 10 bytes correspond to the struct
 206          *          virtio_net_hdr, and the last 2 bytes store the
 207          *          "mergeable buffers" info, which is an optional
 208          *          hint that can be zeroed for compatibility
 209          *
 210          * The destination header is therefore built according to the
 211          * following table:
 212          *
 213          * SHL | DHL | destination header
 214          * -----------------------------
 215          *   0 |  10 | zero
 216          *   0 |  12 | zero
 217          *  10 |   0 | doesn't exist
 218          *  10 |  12 | first 10 bytes are copied from source header, last 2 are zero
 219          *  12 |   0 | doesn't exist
 220          *  12 |  10 | copied from the first 10 bytes of source header
 221          */
 222         bzero(dst, dst_na->up.virt_hdr_len);
 223         if (na->up.virt_hdr_len && dst_na->up.virt_hdr_len)
 224                 memcpy(dst, src, sizeof(struct nm_vnet_hdr));
 225         /* Skip the virtio-net headers. */
 226         src += na->up.virt_hdr_len;
 227         src_len -= na->up.virt_hdr_len;
 228         dst += dst_na->up.virt_hdr_len;
 229         dst_len = dst_na->up.virt_hdr_len + src_len;
 230
 231         /* Here it could be dst_len == 0 (which implies src_len == 0),
 232          * so we avoid passing a zero length fragment.
 233          */
 234         if (dst_len == 0) {
 235                 ft_p++;
 236                 src = ft_p->ft_buf;
 237                 src_len = ft_p->ft_len;
 238                 dst_len = src_len;
 239         }
 240
 241         if (vh && vh->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 242                 u_int gso_bytes = 0;
 243                 /* Length of the GSO packet header. */
 244                 u_int gso_hdr_len = 0;
 245                 /* Pointer to the GSO packet header. Assume it is in a single fragment. */
 246                 uint8_t *gso_hdr = NULL;
 247                 /* Index of the current segment. */
 248                 u_int gso_idx = 0;
 249                 /* Payload data bytes segmented so far (e.g. TCP data bytes). */
 250                 u_int segmented_bytes = 0;
 251                 /* Is this an IPv4 or IPv6 GSO packet? */
 252                 u_int ipv4 = 0;
 253                 /* Length of the IP header (20 if IPv4, 40 if IPv6). */
 254                 u_int iphlen = 0;
 255                 /* Length of the Ethernet header (18 if 802.1q, otherwise 14). */
 256                 u_int ethhlen = 14;
 257                 /* Is this a TCP or an UDP GSO packet? */
 258                 u_int tcp = ((vh->gso_type & ~VIRTIO_NET_HDR_GSO_ECN)
 259                                 == VIRTIO_NET_HDR_GSO_UDP) ? 0 : 1;
 260
 261                 /* Segment the GSO packet contained into the input slots (frags). */
 262                 for (;;) {
 263                         size_t copy;
 264
 265                         if (dst_slots >= *howmany) {
 266                                 /* We still have work to do, but we've run out of
 267                                  * dst slots, so we have to drop the packet. */
 268                                 nm_prdis(1, "Not enough slots, dropping GSO packet");
 269                                 return;
 270                         }
 271
 272                         /* Grab the GSO header if we don't have it. */
 273                         if (!gso_hdr) {
 274                                 uint16_t ethertype;
 275
 276                                 gso_hdr = src;
 277
 278                                 /* Look at the 'Ethertype' field to see if this packet
 279                                  * is IPv4 or IPv6, taking into account VLAN
 280                                  * encapsulation. */
 281                                 for (;;) {
 282                                         if (src_len < ethhlen) {
 283                                                 nm_prlim(1, "Short GSO fragment [eth], dropping");
 284                                                 return;
 285                                         }
 286                                         ethertype = be16toh(*((uint16_t *)
 287                                                             (gso_hdr + ethhlen - 2)));
 288                                         if (ethertype != 0x8100) /* not 802.1q */
 289                                                 break;
 290                                         ethhlen += 4;
 291                                 }
 292                                 switch (ethertype) {
 293                                         case 0x0800:  /* IPv4 */
 294                                         {
 295                                                 struct nm_iphdr *iph = (struct nm_iphdr *)
 296                                                                         (gso_hdr + ethhlen);
 297
 298                                                 if (src_len < ethhlen + 20) {
 299                                                         nm_prlim(1, "Short GSO fragment "
 300                                                               "[IPv4], dropping");
 301                                                         return;
 302                                                 }
 303                                                 ipv4 = 1;
 304                                                 iphlen = 4 * (iph->version_ihl & 0x0F);
 305                                                 break;
 306                                         }
 307                                         case 0x86DD:  /* IPv6 */
 308                                                 ipv4 = 0;
 309                                                 iphlen = 40;
 310                                                 break;
 311                                         default:
 312                                                 nm_prlim(1, "Unsupported ethertype, "
 313                                                       "dropping GSO packet");
 314                                                 return;
 315                                 }
 316                                 nm_prdis(3, "type=%04x", ethertype);
 317
 318                                 if (src_len < ethhlen + iphlen) {
 319                                         nm_prlim(1, "Short GSO fragment [IP], dropping");
 320                                         return;
 321                                 }
 322
 323                                 /* Compute gso_hdr_len. For TCP we need to read the
 324                                  * content of the 'Data Offset' field.
 325                                  */
 326                                 if (tcp) {
 327                                         struct nm_tcphdr *tcph = (struct nm_tcphdr *)
 328                                                                 (gso_hdr + ethhlen + iphlen);
 329
 330                                         if (src_len < ethhlen + iphlen + 20) {
 331                                                 nm_prlim(1, "Short GSO fragment "
 332                                                                 "[TCP], dropping");
 333                                                 return;
 334                                         }
 335                                         gso_hdr_len = ethhlen + iphlen +
 336                                                       4 * (tcph->doff >> 4);
 337                                 } else {
 338                                         gso_hdr_len = ethhlen + iphlen + 8; /* UDP */
 339                                 }
 340
 341                                 if (src_len < gso_hdr_len) {
 342                                         nm_prlim(1, "Short GSO fragment [TCP/UDP], dropping");
 343                                         return;
 344                                 }
 345
 346                                 nm_prdis(3, "gso_hdr_len %u gso_mtu %d", gso_hdr_len,
 347                                                                    dst_na->mfs);
 348
 349                                 /* Advance source pointers. */
 350                                 src += gso_hdr_len;
 351                                 src_len -= gso_hdr_len;
 352                                 if (src_len == 0) {
 353                                         ft_p++;
 354                                         if (ft_p == ft_end)
 355                                                 break;
 356                                         src = ft_p->ft_buf;
 357                                         src_len = ft_p->ft_len;
 358                                 }
 359                         }
 360
 361                         /* Fill in the header of the current segment. */
 362                         if (gso_bytes == 0) {
 363                                 memcpy(dst, gso_hdr, gso_hdr_len);
 364                                 gso_bytes = gso_hdr_len;
 365                         }
 366
 367                         /* Fill in data and update source and dest pointers. */
 368                         copy = src_len;
 369                         if (gso_bytes + copy > dst_na->mfs)
 370                                 copy = dst_na->mfs - gso_bytes;
 371                         memcpy(dst + gso_bytes, src, copy);
 372                         gso_bytes += copy;
 373                         src += copy;
 374                         src_len -= copy;
 375
 376                         /* A segment is complete or we have processed all the
 377                            the GSO payload bytes. */
 378                         if (gso_bytes >= dst_na->mfs ||
 379                                 (src_len == 0 && ft_p + 1 == ft_end)) {
 380                                 /* After raw segmentation, we must fix some header
 381                                  * fields and compute checksums, in a protocol dependent
 382                                  * way. */
 383                                 gso_fix_segment(dst + ethhlen, gso_bytes - ethhlen,
 384                                                 ipv4, iphlen, tcp,
 385                                                 gso_idx, segmented_bytes,
 386                                                 src_len == 0 && ft_p + 1 == ft_end);
 387
 388                                 nm_prdis("frame %u completed with %d bytes", gso_idx, (int)gso_bytes);
 389                                 dst_slot->len = gso_bytes;
 390                                 dst_slot->flags = 0;
 391                                 dst_slots++;
 392                                 segmented_bytes += gso_bytes - gso_hdr_len;
 393
 394                                 gso_bytes = 0;
 395                                 gso_idx++;
 396
 397                                 /* Next destination slot. */
 398                                 j_cur = nm_next(j_cur, lim);
 399                                 dst_slot = &dst_ring->slot[j_cur];
 400                                 dst = NMB(&dst_na->up, dst_slot);
 401                         }
 402
 403                         /* Next input slot. */
 404                         if (src_len == 0) {
 405                                 ft_p++;
 406                                 if (ft_p == ft_end)
 407                                         break;
 408                                 src = ft_p->ft_buf;
 409                                 src_len = ft_p->ft_len;
 410                         }
 411                 }
 412                 nm_prdis(3, "%d bytes segmented", segmented_bytes);
 413
 414         } else {
 415                 /* Address of a checksum field into a destination slot. */
 416                 uint16_t *check = NULL;
 417                 /* Accumulator for an unfolded checksum. */
 418                 rawsum_t csum = 0;
 419
 420                 /* Process a non-GSO packet. */
 421
 422                 /* Init 'check' if necessary. */
 423                 if (vh && (vh->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)) {
 424                         if (unlikely(vh->csum_offset + vh->csum_start > src_len))
 425                                 nm_prerr("invalid checksum request");
 426                         else
 427                                 check = (uint16_t *)(dst + vh->csum_start +
 428                                                 vh->csum_offset);
 429                 }
 430
 431                 while (ft_p != ft_end) {
 432                         /* Init/update the packet checksum if needed. */
 433                         if (vh && (vh->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)) {
 434                                 if (!dst_slots)
 435                                         csum = nm_os_csum_raw(src + vh->csum_start,
 436                                                                 src_len - vh->csum_start, 0);
 437                                 else
 438                                         csum = nm_os_csum_raw(src, src_len, csum);
 439                         }
 440
 441                         /* Round to a multiple of 64 */
 442                         src_len = (src_len + 63) & ~63;
 443
 444                         if (ft_p->ft_flags & NS_INDIRECT) {
 445                                 if (copyin(src, dst, src_len)) {
 446                                         /* Invalid user pointer, pretend len is 0. */
 447                                         dst_len = 0;
 448                                 }
 449                         } else {
 450                                 memcpy(dst, src, (int)src_len);
 451                         }
 452                         dst_slot->len = dst_len;
 453                         dst_slots++;
 454
 455                         /* Next destination slot. */
 456                         j_cur = nm_next(j_cur, lim);
 457                         dst_slot = &dst_ring->slot[j_cur];
 458                         dst = NMB(&dst_na->up, dst_slot);
 459
 460                         /* Next source slot. */
 461                         ft_p++;
 462                         src = ft_p->ft_buf;
 463                         dst_len = src_len = ft_p->ft_len;
 464                 }
 465
 466                 /* Finalize (fold) the checksum if needed. */
 467                 if (check && vh && (vh->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)) {
 468                         *check = nm_os_csum_fold(csum);
 469                 }
 470                 nm_prdis(3, "using %u dst_slots", dst_slots);
 471
 472                 /* A second pass on the destination slots to set the slot flags,
 473                  * using the right number of destination slots.
 474                  */
 475                 while (j_start != j_cur) {
 476                         dst_slot = &dst_ring->slot[j_start];
 477                         dst_slot->flags = (dst_slots << 8)| NS_MOREFRAG;
 478                         j_start = nm_next(j_start, lim);
 479                 }
 480                 /* Clear NS_MOREFRAG flag on last entry. */
 481                 dst_slot->flags = (dst_slots << 8);
 482         }
 483
 484         /* Update howmany and j. This is to commit the use of
 485          * those slots in the destination ring. */
 486         if (unlikely(dst_slots > *howmany)) {
 487                 nm_prerr("bug: slot allocation error");
 488         }
 489         *j = j_cur;
 490         *howmany -= dst_slots;
 491 }