sys/dev/netmap/netmap_offloadings.c

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