drivers/net/xen-netback/hash.c

   1 /*
   2  * Copyright (c) 2016 Citrix Systems Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License version 2
   6  * as published by the Free Softare Foundation; or, when distributed
   7  * separately from the Linux kernel or incorporated into other
   8  * software packages, subject to the following license:
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a copy
  11  * of this source file (the "Software"), to deal in the Software without
  12  * restriction, including without limitation the rights to use, copy, modify,
  13  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
  14  * and to permit persons to whom the Software is furnished to do so, subject to
  15  * the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be included in
  18  * all copies or substantial portions of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  23  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  25  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  26  * IN THE SOFTWARE.
  27  */
  28
  29 #define XEN_NETIF_DEFINE_TOEPLITZ
  30
  31 #include "common.h"
  32 #include <linux/vmalloc.h>
  33 #include <linux/rculist.h>
  34
  35 static void xenvif_del_hash(struct rcu_head *rcu)
  36 {
  37         struct xenvif_hash_cache_entry *entry;
  38
  39         entry = container_of(rcu, struct xenvif_hash_cache_entry, rcu);
  40
  41         kfree(entry);
  42 }
  43
  44 static void xenvif_add_hash(struct xenvif *vif, const u8 *tag,
  45                             unsigned int len, u32 val)
  46 {
  47         struct xenvif_hash_cache_entry *new, *entry, *oldest;
  48         unsigned long flags;
  49         bool found;
  50
  51         new = kmalloc(sizeof(*entry), GFP_KERNEL);
  52         if (!new)
  53                 return;
  54
  55         memcpy(new->tag, tag, len);
  56         new->len = len;
  57         new->val = val;
  58
  59         spin_lock_irqsave(&vif->hash.cache.lock, flags);
  60
  61         found = false;
  62         oldest = NULL;
  63         list_for_each_entry_rcu(entry, &vif->hash.cache.list, link) {
  64                 /* Make sure we don't add duplicate entries */
  65                 if (entry->len == len &&
  66                     memcmp(entry->tag, tag, len) == 0)
  67                         found = true;
  68                 if (!oldest || entry->seq < oldest->seq)
  69                         oldest = entry;
  70         }
  71
  72         if (!found) {
  73                 new->seq = atomic_inc_return(&vif->hash.cache.seq);
  74                 list_add_rcu(&new->link, &vif->hash.cache.list);
  75
  76                 if (++vif->hash.cache.count > xenvif_hash_cache_size) {
  77                         list_del_rcu(&oldest->link);
  78                         vif->hash.cache.count--;
  79                         call_rcu(&oldest->rcu, xenvif_del_hash);
  80                 }
  81         }
  82
  83         spin_unlock_irqrestore(&vif->hash.cache.lock, flags);
  84
  85         if (found)
  86                 kfree(new);
  87 }
  88
  89 static u32 xenvif_new_hash(struct xenvif *vif, const u8 *data,
  90                            unsigned int len)
  91 {
  92         u32 val;
  93
  94         val = xen_netif_toeplitz_hash(vif->hash.key,
  95                                       sizeof(vif->hash.key),
  96                                       data, len);
  97
  98         if (xenvif_hash_cache_size != 0)
  99                 xenvif_add_hash(vif, data, len, val);
 100
 101         return val;
 102 }
 103
 104 static void xenvif_flush_hash(struct xenvif *vif)
 105 {
 106         struct xenvif_hash_cache_entry *entry;
 107         unsigned long flags;
 108
 109         if (xenvif_hash_cache_size == 0)
 110                 return;
 111
 112         spin_lock_irqsave(&vif->hash.cache.lock, flags);
 113
 114         list_for_each_entry_rcu(entry, &vif->hash.cache.list, link) {
 115                 list_del_rcu(&entry->link);
 116                 vif->hash.cache.count--;
 117                 call_rcu(&entry->rcu, xenvif_del_hash);
 118         }
 119
 120         spin_unlock_irqrestore(&vif->hash.cache.lock, flags);
 121 }
 122
 123 static u32 xenvif_find_hash(struct xenvif *vif, const u8 *data,
 124                             unsigned int len)
 125 {
 126         struct xenvif_hash_cache_entry *entry;
 127         u32 val;
 128         bool found;
 129
 130         if (len >= XEN_NETBK_HASH_TAG_SIZE)
 131                 return 0;
 132
 133         if (xenvif_hash_cache_size == 0)
 134                 return xenvif_new_hash(vif, data, len);
 135
 136         rcu_read_lock();
 137
 138         found = false;
 139
 140         list_for_each_entry_rcu(entry, &vif->hash.cache.list, link) {
 141                 if (entry->len == len &&
 142                     memcmp(entry->tag, data, len) == 0) {
 143                         val = entry->val;
 144                         entry->seq = atomic_inc_return(&vif->hash.cache.seq);
 145                         found = true;
 146                         break;
 147                 }
 148         }
 149
 150         rcu_read_unlock();
 151
 152         if (!found)
 153                 val = xenvif_new_hash(vif, data, len);
 154
 155         return val;
 156 }
 157
 158 void xenvif_set_skb_hash(struct xenvif *vif, struct sk_buff *skb)
 159 {
 160         struct flow_keys flow;
 161         u32 hash = 0;
 162         enum pkt_hash_types type = PKT_HASH_TYPE_NONE;
 163         u32 flags = vif->hash.flags;
 164         bool has_tcp_hdr;
 165
 166         /* Quick rejection test: If the network protocol doesn't
 167          * correspond to any enabled hash type then there's no point
 168          * in parsing the packet header.
 169          */
 170         switch (skb->protocol) {
 171         case htons(ETH_P_IP):
 172                 if (flags & (XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP |
 173                              XEN_NETIF_CTRL_HASH_TYPE_IPV4))
 174                         break;
 175
 176                 goto done;
 177
 178         case htons(ETH_P_IPV6):
 179                 if (flags & (XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP |
 180                              XEN_NETIF_CTRL_HASH_TYPE_IPV6))
 181                         break;
 182
 183                 goto done;
 184
 185         default:
 186                 goto done;
 187         }
 188
 189         memset(&flow, 0, sizeof(flow));
 190         if (!skb_flow_dissect_flow_keys(skb, &flow, 0))
 191                 goto done;
 192
 193         has_tcp_hdr = (flow.basic.ip_proto == IPPROTO_TCP) &&
 194                       !(flow.control.flags & FLOW_DIS_IS_FRAGMENT);
 195
 196         switch (skb->protocol) {
 197         case htons(ETH_P_IP):
 198                 if (has_tcp_hdr &&
 199                     (flags & XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP)) {
 200                         u8 data[12];
 201
 202                         memcpy(&data[0], &flow.addrs.v4addrs.src, 4);
 203                         memcpy(&data[4], &flow.addrs.v4addrs.dst, 4);
 204                         memcpy(&data[8], &flow.ports.src, 2);
 205                         memcpy(&data[10], &flow.ports.dst, 2);
 206
 207                         hash = xenvif_find_hash(vif, data, sizeof(data));
 208                         type = PKT_HASH_TYPE_L4;
 209                 } else if (flags & XEN_NETIF_CTRL_HASH_TYPE_IPV4) {
 210                         u8 data[8];
 211
 212                         memcpy(&data[0], &flow.addrs.v4addrs.src, 4);
 213                         memcpy(&data[4], &flow.addrs.v4addrs.dst, 4);
 214
 215                         hash = xenvif_find_hash(vif, data, sizeof(data));
 216                         type = PKT_HASH_TYPE_L3;
 217                 }
 218
 219                 break;
 220
 221         case htons(ETH_P_IPV6):
 222                 if (has_tcp_hdr &&
 223                     (flags & XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP)) {
 224                         u8 data[36];
 225
 226                         memcpy(&data[0], &flow.addrs.v6addrs.src, 16);
 227                         memcpy(&data[16], &flow.addrs.v6addrs.dst, 16);
 228                         memcpy(&data[32], &flow.ports.src, 2);
 229                         memcpy(&data[34], &flow.ports.dst, 2);
 230
 231                         hash = xenvif_find_hash(vif, data, sizeof(data));
 232                         type = PKT_HASH_TYPE_L4;
 233                 } else if (flags & XEN_NETIF_CTRL_HASH_TYPE_IPV6) {
 234                         u8 data[32];
 235
 236                         memcpy(&data[0], &flow.addrs.v6addrs.src, 16);
 237                         memcpy(&data[16], &flow.addrs.v6addrs.dst, 16);
 238
 239                         hash = xenvif_find_hash(vif, data, sizeof(data));
 240                         type = PKT_HASH_TYPE_L3;
 241                 }
 242
 243                 break;
 244         }
 245
 246 done:
 247         if (type == PKT_HASH_TYPE_NONE)
 248                 skb_clear_hash(skb);
 249         else
 250                 __skb_set_sw_hash(skb, hash, type == PKT_HASH_TYPE_L4);
 251 }
 252
 253 u32 xenvif_set_hash_alg(struct xenvif *vif, u32 alg)
 254 {
 255         switch (alg) {
 256         case XEN_NETIF_CTRL_HASH_ALGORITHM_NONE:
 257         case XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ:
 258                 break;
 259
 260         default:
 261                 return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
 262         }
 263
 264         vif->hash.alg = alg;
 265
 266         return XEN_NETIF_CTRL_STATUS_SUCCESS;
 267 }
 268
 269 u32 xenvif_get_hash_flags(struct xenvif *vif, u32 *flags)
 270 {
 271         if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE)
 272                 return XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED;
 273
 274         *flags = XEN_NETIF_CTRL_HASH_TYPE_IPV4 |
 275                  XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP |
 276                  XEN_NETIF_CTRL_HASH_TYPE_IPV6 |
 277                  XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP;
 278
 279         return XEN_NETIF_CTRL_STATUS_SUCCESS;
 280 }
 281
 282 u32 xenvif_set_hash_flags(struct xenvif *vif, u32 flags)
 283 {
 284         if (flags & ~(XEN_NETIF_CTRL_HASH_TYPE_IPV4 |
 285                       XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP |
 286                       XEN_NETIF_CTRL_HASH_TYPE_IPV6 |
 287                       XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP))
 288                 return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
 289
 290         if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE)
 291                 return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
 292
 293         vif->hash.flags = flags;
 294
 295         return XEN_NETIF_CTRL_STATUS_SUCCESS;
 296 }
 297
 298 u32 xenvif_set_hash_key(struct xenvif *vif, u32 gref, u32 len)
 299 {
 300         u8 *key = vif->hash.key;
 301         struct gnttab_copy copy_op = {
 302                 .source.u.ref = gref,
 303                 .source.domid = vif->domid,
 304                 .dest.u.gmfn = virt_to_gfn(key),
 305                 .dest.domid = DOMID_SELF,
 306                 .dest.offset = xen_offset_in_page(key),
 307                 .len = len,
 308                 .flags = GNTCOPY_source_gref
 309         };
 310
 311         if (len > XEN_NETBK_MAX_HASH_KEY_SIZE)
 312                 return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
 313
 314         if (len != 0) {
 315                 gnttab_batch_copy(&copy_op, 1);
 316
 317                 if (copy_op.status != GNTST_okay)
 318                         return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
 319         }
 320
 321         /* Clear any remaining key octets */
 322         if (len < XEN_NETBK_MAX_HASH_KEY_SIZE)
 323                 memset(key + len, 0, XEN_NETBK_MAX_HASH_KEY_SIZE - len);
 324
 325         xenvif_flush_hash(vif);
 326
 327         return XEN_NETIF_CTRL_STATUS_SUCCESS;
 328 }
 329
 330 u32 xenvif_set_hash_mapping_size(struct xenvif *vif, u32 size)
 331 {
 332         if (size > XEN_NETBK_MAX_HASH_MAPPING_SIZE)
 333                 return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
 334
 335         vif->hash.size = size;
 336         memset(vif->hash.mapping, 0, sizeof(u32) * size);
 337
 338         return XEN_NETIF_CTRL_STATUS_SUCCESS;
 339 }
 340
 341 u32 xenvif_set_hash_mapping(struct xenvif *vif, u32 gref, u32 len,
 342                             u32 off)
 343 {
 344         u32 *mapping = &vif->hash.mapping[off];
 345         struct gnttab_copy copy_op = {
 346                 .source.u.ref = gref,
 347                 .source.domid = vif->domid,
 348                 .dest.u.gmfn = virt_to_gfn(mapping),
 349                 .dest.domid = DOMID_SELF,
 350                 .dest.offset = xen_offset_in_page(mapping),
 351                 .len = len * sizeof(u32),
 352                 .flags = GNTCOPY_source_gref
 353         };
 354
 355         if ((off + len > vif->hash.size) || copy_op.len > XEN_PAGE_SIZE)
 356                 return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
 357
 358         while (len-- != 0)
 359                 if (mapping[off++] >= vif->num_queues)
 360                         return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
 361
 362         if (len != 0) {
 363                 gnttab_batch_copy(&copy_op, 1);
 364
 365                 if (copy_op.status != GNTST_okay)
 366                         return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
 367         }
 368
 369         return XEN_NETIF_CTRL_STATUS_SUCCESS;
 370 }
 371
 372 void xenvif_init_hash(struct xenvif *vif)
 373 {
 374         if (xenvif_hash_cache_size == 0)
 375                 return;
 376
 377         spin_lock_init(&vif->hash.cache.lock);
 378         INIT_LIST_HEAD(&vif->hash.cache.list);
 379 }
 380
 381 void xenvif_deinit_hash(struct xenvif *vif)
 382 {
 383         xenvif_flush_hash(vif);
 384 }