sys/netinet/tcp_fastopen.c

   1 /*-
   2  * Copyright (c) 2015-2017 Patrick Kelsey
   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 /*
  28  * This is an implementation of TCP Fast Open (TFO) [RFC7413]. To include
  29  * this code, add the following line to your kernel config:
  30  *
  31  * options TCP_RFC7413
  32  *
  33  *
  34  * The generated TFO cookies are the 64-bit output of
  35  * SipHash24(key=<16-byte-key>, msg=<client-ip>).  Multiple concurrent valid
  36  * keys are supported so that time-based rolling cookie invalidation
  37  * policies can be implemented in the system.  The default number of
  38  * concurrent keys is 2.  This can be adjusted in the kernel config as
  39  * follows:
  40  *
  41  * options TCP_RFC7413_MAX_KEYS=<num-keys>
  42  *
  43  *
  44  * In addition to the facilities defined in RFC7413, this implementation
  45  * supports a pre-shared key (PSK) mode of operation in which the TFO server
  46  * requires the client to be in posession of a shared secret in order for
  47  * the client to be able to successfully open TFO connections with the
  48  * server.  This is useful, for example, in environments where TFO servers
  49  * are exposed to both internal and external clients and only wish to allow
  50  * TFO connections from internal clients.
  51  *
  52  * In the PSK mode of operation, the server generates and sends TFO cookies
  53  * to requesting clients as usual.  However, when validating cookies
  54  * received in TFO SYNs from clients, the server requires the
  55  * client-supplied cookie to equal SipHash24(key=<16-byte-psk>,
  56  * msg=<cookie-sent-to-client>).
  57  *
  58  * Multiple concurrent valid pre-shared keys are supported so that
  59  * time-based rolling PSK invalidation policies can be implemented in the
  60  * system.  The default number of concurrent pre-shared keys is 2.  This can
  61  * be adjusted in the kernel config as follows:
  62  *
  63  * options TCP_RFC7413_MAX_PSKS=<num-psks>
  64  *
  65  *
  66  * The following TFO-specific sysctls are defined:
  67  *
  68  * net.inet.tcp.fastopen.acceptany (RW, default 0)
  69  *     When non-zero, all client-supplied TFO cookies will be considered to
  70  *     be valid.
  71  *
  72  * net.inet.tcp.fastopen.autokey (RW, default 120)
  73  *     When this and net.inet.tcp.fastopen.server_enable are non-zero, a new
  74  *     key will be automatically generated after this many seconds.
  75  *
  76  * net.inet.tcp.fastopen.ccache_bucket_limit
  77  *                     (RWTUN, default TCP_FASTOPEN_CCACHE_BUCKET_LIMIT_DEFAULT)
  78  *     The maximum number of entries in a client cookie cache bucket.
  79  *
  80  * net.inet.tcp.fastopen.ccache_buckets
  81  *                          (RDTUN, default TCP_FASTOPEN_CCACHE_BUCKETS_DEFAULT)
  82  *     The number of client cookie cache buckets.
  83  *
  84  * net.inet.tcp.fastopen.ccache_list (RO)
  85  *     Print the client cookie cache.
  86  *
  87  * net.inet.tcp.fastopen.client_enable (RW, default 0)
  88  *     When zero, no new active (i.e., client) TFO connections can be
  89  *     created.  On the transition from enabled to disabled, the client
  90  *     cookie cache is cleared and disabled.  The transition from enabled to
  91  *     disabled does not affect any active TFO connections in progress; it
  92  *     only prevents new ones from being made.
  93  *
  94  * net.inet.tcp.fastopen.keylen (RD)
  95  *     The key length in bytes.
  96  *
  97  * net.inet.tcp.fastopen.maxkeys (RD)
  98  *     The maximum number of keys supported.
  99  *
 100  * net.inet.tcp.fastopen.maxpsks (RD)
 101  *     The maximum number of pre-shared keys supported.
 102  *
 103  * net.inet.tcp.fastopen.numkeys (RD)
 104  *     The current number of keys installed.
 105  *
 106  * net.inet.tcp.fastopen.numpsks (RD)
 107  *     The current number of pre-shared keys installed.
 108  *
 109  * net.inet.tcp.fastopen.path_disable_time
 110  *                          (RW, default TCP_FASTOPEN_PATH_DISABLE_TIME_DEFAULT)
 111  *     When a failure occurs while trying to create a new active (i.e.,
 112  *     client) TFO connection, new active connections on the same path, as
 113  *     determined by the tuple {client_ip, server_ip, server_port}, will be
 114  *     forced to be non-TFO for this many seconds.  Note that the path
 115  *     disable mechanism relies on state stored in client cookie cache
 116  *     entries, so it is possible for the disable time for a given path to
 117  *     be reduced if the corresponding client cookie cache entry is reused
 118  *     due to resource pressure before the disable period has elapsed.
 119  *
 120  * net.inet.tcp.fastopen.psk_enable (RW, default 0)
 121  *     When non-zero, pre-shared key (PSK) mode is enabled for all TFO
 122  *     servers.  On the transition from enabled to disabled, all installed
 123  *     pre-shared keys are removed.
 124  *
 125  * net.inet.tcp.fastopen.server_enable (RW, default 0)
 126  *     When zero, no new passive (i.e., server) TFO connections can be
 127  *     created.  On the transition from enabled to disabled, all installed
 128  *     keys and pre-shared keys are removed.  On the transition from
 129  *     disabled to enabled, if net.inet.tcp.fastopen.autokey is non-zero and
 130  *     there are no keys installed, a new key will be generated immediately.
 131  *     The transition from enabled to disabled does not affect any passive
 132  *     TFO connections in progress; it only prevents new ones from being
 133  *     made.
 134  *
 135  * net.inet.tcp.fastopen.setkey (WR)
 136  *     Install a new key by writing net.inet.tcp.fastopen.keylen bytes to
 137  *     this sysctl.
 138  *
 139  * net.inet.tcp.fastopen.setpsk (WR)
 140  *     Install a new pre-shared key by writing net.inet.tcp.fastopen.keylen
 141  *     bytes to this sysctl.
 142  *
 143  * In order for TFO connections to be created via a listen socket, that
 144  * socket must have the TCP_FASTOPEN socket option set on it.  This option
 145  * can be set on the socket either before or after the listen() is invoked.
 146  * Clearing this option on a listen socket after it has been set has no
 147  * effect on existing TFO connections or TFO connections in progress; it
 148  * only prevents new TFO connections from being made.
 149  *
 150  * For passively-created sockets, the TCP_FASTOPEN socket option can be
 151  * queried to determine whether the connection was established using TFO.
 152  * Note that connections that are established via a TFO SYN, but that fall
 153  * back to using a non-TFO SYN|ACK will have the TCP_FASTOPEN socket option
 154  * set.
 155  *
 156  * Per the RFC, this implementation limits the number of TFO connections
 157  * that can be in the SYN_RECEIVED state on a per listen-socket basis.
 158  * Whenever this limit is exceeded, requests for new TFO connections are
 159  * serviced as non-TFO requests.  Without such a limit, given a valid TFO
 160  * cookie, an attacker could keep the listen queue in an overflow condition
 161  * using a TFO SYN flood.  This implementation sets the limit at half the
 162  * configured listen backlog.
 163  *
 164  */
 165
 166 #include <sys/cdefs.h>
 167 __FBSDID("$FreeBSD$");
 168
 169 #include "opt_inet.h"
 170
 171 #include <sys/param.h>
 172 #include <sys/jail.h>
 173 #include <sys/kernel.h>
 174 #include <sys/hash.h>
 175 #include <sys/limits.h>
 176 #include <sys/lock.h>
 177 #include <sys/proc.h>
 178 #include <sys/rmlock.h>
 179 #include <sys/sbuf.h>
 180 #include <sys/socket.h>
 181 #include <sys/socketvar.h>
 182 #include <sys/sysctl.h>
 183 #include <sys/systm.h>
 184
 185 #include <crypto/siphash/siphash.h>
 186
 187 #include <net/vnet.h>
 188
 189 #include <netinet/in.h>
 190 #include <netinet/in_pcb.h>
 191 #include <netinet/tcp_var.h>
 192 #include <netinet/tcp_fastopen.h>
 193
 194
 195 #define TCP_FASTOPEN_KEY_LEN    SIPHASH_KEY_LENGTH
 196
 197 #if TCP_FASTOPEN_PSK_LEN != TCP_FASTOPEN_KEY_LEN
 198 #error TCP_FASTOPEN_PSK_LEN must be equal to TCP_FASTOPEN_KEY_LEN
 199 #endif
 200
 201 /*
 202  * Because a PSK-mode setsockopt() uses tcpcb.t_tfo_cookie.client to hold
 203  * the PSK until the connect occurs.
 204  */
 205 #if TCP_FASTOPEN_MAX_COOKIE_LEN < TCP_FASTOPEN_PSK_LEN
 206 #error TCP_FASTOPEN_MAX_COOKIE_LEN must be >= TCP_FASTOPEN_PSK_LEN
 207 #endif
 208
 209 #define TCP_FASTOPEN_CCACHE_BUCKET_LIMIT_DEFAULT        16
 210 #define TCP_FASTOPEN_CCACHE_BUCKETS_DEFAULT             2048 /* must be power of 2 */
 211
 212 #define TCP_FASTOPEN_PATH_DISABLE_TIME_DEFAULT          900 /* seconds */
 213
 214 #if !defined(TCP_RFC7413_MAX_KEYS) || (TCP_RFC7413_MAX_KEYS < 1)
 215 #define TCP_FASTOPEN_MAX_KEYS   2
 216 #else
 217 #define TCP_FASTOPEN_MAX_KEYS   TCP_RFC7413_MAX_KEYS
 218 #endif
 219
 220 #if TCP_FASTOPEN_MAX_KEYS > 10
 221 #undef TCP_FASTOPEN_MAX_KEYS
 222 #define TCP_FASTOPEN_MAX_KEYS   10
 223 #endif
 224
 225 #if !defined(TCP_RFC7413_MAX_PSKS) || (TCP_RFC7413_MAX_PSKS < 1)
 226 #define TCP_FASTOPEN_MAX_PSKS   2
 227 #else
 228 #define TCP_FASTOPEN_MAX_PSKS   TCP_RFC7413_MAX_PSKS
 229 #endif
 230
 231 #if TCP_FASTOPEN_MAX_PSKS > 10
 232 #undef TCP_FASTOPEN_MAX_PSKS
 233 #define TCP_FASTOPEN_MAX_PSKS   10
 234 #endif
 235
 236 struct tcp_fastopen_keylist {
 237         unsigned int newest;
 238         unsigned int newest_psk;
 239         uint8_t key[TCP_FASTOPEN_MAX_KEYS][TCP_FASTOPEN_KEY_LEN];
 240         uint8_t psk[TCP_FASTOPEN_MAX_PSKS][TCP_FASTOPEN_KEY_LEN];
 241 };
 242
 243 struct tcp_fastopen_callout {
 244         struct callout c;
 245         struct vnet *v;
 246 };
 247
 248 static struct tcp_fastopen_ccache_entry *tcp_fastopen_ccache_lookup(
 249     struct in_conninfo *, struct tcp_fastopen_ccache_bucket **);
 250 static struct tcp_fastopen_ccache_entry *tcp_fastopen_ccache_create(
 251     struct tcp_fastopen_ccache_bucket *, struct in_conninfo *, uint16_t, uint8_t,
 252     uint8_t *);
 253 static void tcp_fastopen_ccache_bucket_trim(struct tcp_fastopen_ccache_bucket *,
 254     unsigned int);
 255 static void tcp_fastopen_ccache_entry_drop(struct tcp_fastopen_ccache_entry *,
 256     struct tcp_fastopen_ccache_bucket *);
 257
 258 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, fastopen, CTLFLAG_RW, 0, "TCP Fast Open");
 259
 260 VNET_DEFINE_STATIC(int, tcp_fastopen_acceptany) = 0;
 261 #define V_tcp_fastopen_acceptany        VNET(tcp_fastopen_acceptany)
 262 SYSCTL_INT(_net_inet_tcp_fastopen, OID_AUTO, acceptany,
 263     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_fastopen_acceptany), 0,
 264     "Accept any non-empty cookie");
 265
 266 VNET_DEFINE_STATIC(unsigned int, tcp_fastopen_autokey) = 120;
 267 #define V_tcp_fastopen_autokey  VNET(tcp_fastopen_autokey)
 268 static int sysctl_net_inet_tcp_fastopen_autokey(SYSCTL_HANDLER_ARGS);
 269 SYSCTL_PROC(_net_inet_tcp_fastopen, OID_AUTO, autokey,
 270     CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, NULL, 0,
 271     &sysctl_net_inet_tcp_fastopen_autokey, "IU",
 272     "Number of seconds between auto-generation of a new key; zero disables");
 273
 274 static int sysctl_net_inet_tcp_fastopen_ccache_bucket_limit(SYSCTL_HANDLER_ARGS);
 275 SYSCTL_PROC(_net_inet_tcp_fastopen, OID_AUTO, ccache_bucket_limit,
 276     CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RWTUN, NULL, 0,
 277     &sysctl_net_inet_tcp_fastopen_ccache_bucket_limit, "IU",
 278     "Max entries per bucket in client cookie cache");
 279
 280 VNET_DEFINE_STATIC(unsigned int, tcp_fastopen_ccache_buckets) =
 281     TCP_FASTOPEN_CCACHE_BUCKETS_DEFAULT;
 282 #define V_tcp_fastopen_ccache_buckets VNET(tcp_fastopen_ccache_buckets)
 283 SYSCTL_UINT(_net_inet_tcp_fastopen, OID_AUTO, ccache_buckets,
 284     CTLFLAG_VNET | CTLFLAG_RDTUN, &VNET_NAME(tcp_fastopen_ccache_buckets), 0,
 285     "Client cookie cache number of buckets (power of 2)");
 286
 287 VNET_DEFINE(unsigned int, tcp_fastopen_client_enable) = 1;
 288 static int sysctl_net_inet_tcp_fastopen_client_enable(SYSCTL_HANDLER_ARGS);
 289 SYSCTL_PROC(_net_inet_tcp_fastopen, OID_AUTO, client_enable,
 290     CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, NULL, 0,
 291     &sysctl_net_inet_tcp_fastopen_client_enable, "IU",
 292     "Enable/disable TCP Fast Open client functionality");
 293
 294 SYSCTL_INT(_net_inet_tcp_fastopen, OID_AUTO, keylen,
 295     CTLFLAG_RD, SYSCTL_NULL_INT_PTR, TCP_FASTOPEN_KEY_LEN,
 296     "Key length in bytes");
 297
 298 SYSCTL_INT(_net_inet_tcp_fastopen, OID_AUTO, maxkeys,
 299     CTLFLAG_RD, SYSCTL_NULL_INT_PTR, TCP_FASTOPEN_MAX_KEYS,
 300     "Maximum number of keys supported");
 301
 302 SYSCTL_INT(_net_inet_tcp_fastopen, OID_AUTO, maxpsks,
 303     CTLFLAG_RD, SYSCTL_NULL_INT_PTR, TCP_FASTOPEN_MAX_PSKS,
 304     "Maximum number of pre-shared keys supported");
 305
 306 VNET_DEFINE_STATIC(unsigned int, tcp_fastopen_numkeys) = 0;
 307 #define V_tcp_fastopen_numkeys  VNET(tcp_fastopen_numkeys)
 308 SYSCTL_UINT(_net_inet_tcp_fastopen, OID_AUTO, numkeys,
 309     CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(tcp_fastopen_numkeys), 0,
 310     "Number of keys installed");
 311
 312 VNET_DEFINE_STATIC(unsigned int, tcp_fastopen_numpsks) = 0;
 313 #define V_tcp_fastopen_numpsks  VNET(tcp_fastopen_numpsks)
 314 SYSCTL_UINT(_net_inet_tcp_fastopen, OID_AUTO, numpsks,
 315     CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(tcp_fastopen_numpsks), 0,
 316     "Number of pre-shared keys installed");
 317
 318 VNET_DEFINE_STATIC(unsigned int, tcp_fastopen_path_disable_time) =
 319     TCP_FASTOPEN_PATH_DISABLE_TIME_DEFAULT;
 320 #define V_tcp_fastopen_path_disable_time VNET(tcp_fastopen_path_disable_time)
 321 SYSCTL_UINT(_net_inet_tcp_fastopen, OID_AUTO, path_disable_time,
 322     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_fastopen_path_disable_time), 0,
 323     "Seconds a TFO failure disables a {client_ip, server_ip, server_port} path");
 324
 325 VNET_DEFINE_STATIC(unsigned int, tcp_fastopen_psk_enable) = 0;
 326 #define V_tcp_fastopen_psk_enable       VNET(tcp_fastopen_psk_enable)
 327 static int sysctl_net_inet_tcp_fastopen_psk_enable(SYSCTL_HANDLER_ARGS);
 328 SYSCTL_PROC(_net_inet_tcp_fastopen, OID_AUTO, psk_enable,
 329     CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, NULL, 0,
 330     &sysctl_net_inet_tcp_fastopen_psk_enable, "IU",
 331     "Enable/disable TCP Fast Open server pre-shared key mode");
 332
 333 VNET_DEFINE(unsigned int, tcp_fastopen_server_enable) = 0;
 334 static int sysctl_net_inet_tcp_fastopen_server_enable(SYSCTL_HANDLER_ARGS);
 335 SYSCTL_PROC(_net_inet_tcp_fastopen, OID_AUTO, server_enable,
 336     CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, NULL, 0,
 337     &sysctl_net_inet_tcp_fastopen_server_enable, "IU",
 338     "Enable/disable TCP Fast Open server functionality");
 339
 340 static int sysctl_net_inet_tcp_fastopen_setkey(SYSCTL_HANDLER_ARGS);
 341 SYSCTL_PROC(_net_inet_tcp_fastopen, OID_AUTO, setkey,
 342     CTLFLAG_VNET | CTLTYPE_OPAQUE | CTLFLAG_WR, NULL, 0,
 343     &sysctl_net_inet_tcp_fastopen_setkey, "",
 344     "Install a new key");
 345
 346 static int sysctl_net_inet_tcp_fastopen_setpsk(SYSCTL_HANDLER_ARGS);
 347 SYSCTL_PROC(_net_inet_tcp_fastopen, OID_AUTO, setpsk,
 348     CTLFLAG_VNET | CTLTYPE_OPAQUE | CTLFLAG_WR, NULL, 0,
 349     &sysctl_net_inet_tcp_fastopen_setpsk, "",
 350     "Install a new pre-shared key");
 351
 352 static int sysctl_net_inet_tcp_fastopen_ccache_list(SYSCTL_HANDLER_ARGS);
 353 SYSCTL_PROC(_net_inet_tcp_fastopen, OID_AUTO, ccache_list,
 354     CTLFLAG_VNET | CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP, NULL, 0,
 355     sysctl_net_inet_tcp_fastopen_ccache_list, "A",
 356     "List of all client cookie cache entries");
 357
 358 VNET_DEFINE_STATIC(struct rmlock, tcp_fastopen_keylock);
 359 #define V_tcp_fastopen_keylock  VNET(tcp_fastopen_keylock)
 360
 361 #define TCP_FASTOPEN_KEYS_RLOCK(t)      rm_rlock(&V_tcp_fastopen_keylock, (t))
 362 #define TCP_FASTOPEN_KEYS_RUNLOCK(t)    rm_runlock(&V_tcp_fastopen_keylock, (t))
 363 #define TCP_FASTOPEN_KEYS_WLOCK()       rm_wlock(&V_tcp_fastopen_keylock)
 364 #define TCP_FASTOPEN_KEYS_WUNLOCK()     rm_wunlock(&V_tcp_fastopen_keylock)
 365
 366 VNET_DEFINE_STATIC(struct tcp_fastopen_keylist, tcp_fastopen_keys);
 367 #define V_tcp_fastopen_keys     VNET(tcp_fastopen_keys)
 368
 369 VNET_DEFINE_STATIC(struct tcp_fastopen_callout, tcp_fastopen_autokey_ctx);
 370 #define V_tcp_fastopen_autokey_ctx      VNET(tcp_fastopen_autokey_ctx)
 371
 372 VNET_DEFINE_STATIC(uma_zone_t, counter_zone);
 373 #define V_counter_zone                  VNET(counter_zone)
 374
 375 static MALLOC_DEFINE(M_TCP_FASTOPEN_CCACHE, "tfo_ccache", "TFO client cookie cache buckets");
 376
 377 VNET_DEFINE_STATIC(struct tcp_fastopen_ccache, tcp_fastopen_ccache);
 378 #define V_tcp_fastopen_ccache   VNET(tcp_fastopen_ccache)
 379
 380 #define CCB_LOCK(ccb)           mtx_lock(&(ccb)->ccb_mtx)
 381 #define CCB_UNLOCK(ccb)         mtx_unlock(&(ccb)->ccb_mtx)
 382 #define CCB_LOCK_ASSERT(ccb)    mtx_assert(&(ccb)->ccb_mtx, MA_OWNED)
 383
 384
 385 void
 386 tcp_fastopen_init(void)
 387 {
 388         unsigned int i;
 389
 390         V_counter_zone = uma_zcreate("tfo", sizeof(unsigned int),
 391             NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
 392         rm_init(&V_tcp_fastopen_keylock, "tfo_keylock");
 393         callout_init_rm(&V_tcp_fastopen_autokey_ctx.c,
 394             &V_tcp_fastopen_keylock, 0);
 395         V_tcp_fastopen_autokey_ctx.v = curvnet;
 396         V_tcp_fastopen_keys.newest = TCP_FASTOPEN_MAX_KEYS - 1;
 397         V_tcp_fastopen_keys.newest_psk = TCP_FASTOPEN_MAX_PSKS - 1;
 398
 399         /* May already be non-zero if kernel tunable was set */
 400         if (V_tcp_fastopen_ccache.bucket_limit == 0)
 401                 V_tcp_fastopen_ccache.bucket_limit =
 402                     TCP_FASTOPEN_CCACHE_BUCKET_LIMIT_DEFAULT;
 403
 404         /* May already be non-zero if kernel tunable was set */
 405         if ((V_tcp_fastopen_ccache_buckets == 0) ||
 406             !powerof2(V_tcp_fastopen_ccache_buckets))
 407                 V_tcp_fastopen_ccache.buckets =
 408                         TCP_FASTOPEN_CCACHE_BUCKETS_DEFAULT;
 409         else
 410                 V_tcp_fastopen_ccache.buckets = V_tcp_fastopen_ccache_buckets;
 411
 412         V_tcp_fastopen_ccache.mask = V_tcp_fastopen_ccache.buckets - 1;
 413         V_tcp_fastopen_ccache.secret = arc4random();
 414
 415         V_tcp_fastopen_ccache.base = malloc(V_tcp_fastopen_ccache.buckets *
 416             sizeof(struct tcp_fastopen_ccache_bucket), M_TCP_FASTOPEN_CCACHE,
 417             M_WAITOK | M_ZERO);
 418
 419         for (i = 0; i < V_tcp_fastopen_ccache.buckets; i++) {
 420                 TAILQ_INIT(&V_tcp_fastopen_ccache.base[i].ccb_entries);
 421                 mtx_init(&V_tcp_fastopen_ccache.base[i].ccb_mtx, "tfo_ccache_bucket",
 422                          NULL, MTX_DEF);
 423                 if (V_tcp_fastopen_client_enable) {
 424                         /* enable bucket */
 425                         V_tcp_fastopen_ccache.base[i].ccb_num_entries = 0;
 426                 } else {
 427                         /* disable bucket */
 428                         V_tcp_fastopen_ccache.base[i].ccb_num_entries = -1;
 429                 }
 430                 V_tcp_fastopen_ccache.base[i].ccb_ccache = &V_tcp_fastopen_ccache;
 431         }
 432
 433         /*
 434          * Note that while the total number of entries in the cookie cache
 435          * is limited by the table management logic to
 436          * V_tcp_fastopen_ccache.buckets *
 437          * V_tcp_fastopen_ccache.bucket_limit, the total number of items in
 438          * this zone can exceed that amount by the number of CPUs in the
 439          * system times the maximum number of unallocated items that can be
 440          * present in each UMA per-CPU cache for this zone.
 441          */
 442         V_tcp_fastopen_ccache.zone = uma_zcreate("tfo_ccache_entries",
 443             sizeof(struct tcp_fastopen_ccache_entry), NULL, NULL, NULL, NULL,
 444             UMA_ALIGN_CACHE, 0);
 445 }
 446
 447 void
 448 tcp_fastopen_destroy(void)
 449 {
 450         struct tcp_fastopen_ccache_bucket *ccb;
 451         unsigned int i;
 452
 453         for (i = 0; i < V_tcp_fastopen_ccache.buckets; i++) {
 454                 ccb = &V_tcp_fastopen_ccache.base[i];
 455                 tcp_fastopen_ccache_bucket_trim(ccb, 0);
 456                 mtx_destroy(&ccb->ccb_mtx);
 457         }
 458
 459         KASSERT(uma_zone_get_cur(V_tcp_fastopen_ccache.zone) == 0,
 460             ("%s: TFO ccache zone allocation count not 0", __func__));
 461         uma_zdestroy(V_tcp_fastopen_ccache.zone);
 462         free(V_tcp_fastopen_ccache.base, M_TCP_FASTOPEN_CCACHE);
 463
 464         callout_drain(&V_tcp_fastopen_autokey_ctx.c);
 465         rm_destroy(&V_tcp_fastopen_keylock);
 466         uma_zdestroy(V_counter_zone);
 467 }
 468
 469 unsigned int *
 470 tcp_fastopen_alloc_counter(void)
 471 {
 472         unsigned int *counter;
 473         counter = uma_zalloc(V_counter_zone, M_NOWAIT);
 474         if (counter)
 475                 *counter = 1;
 476         return (counter);
 477 }
 478
 479 void
 480 tcp_fastopen_decrement_counter(unsigned int *counter)
 481 {
 482         if (*counter == 1)
 483                 uma_zfree(V_counter_zone, counter);
 484         else
 485                 atomic_subtract_int(counter, 1);
 486 }
 487
 488 static void
 489 tcp_fastopen_addkey_locked(uint8_t *key)
 490 {
 491
 492         V_tcp_fastopen_keys.newest++;
 493         if (V_tcp_fastopen_keys.newest == TCP_FASTOPEN_MAX_KEYS)
 494                 V_tcp_fastopen_keys.newest = 0;
 495         memcpy(V_tcp_fastopen_keys.key[V_tcp_fastopen_keys.newest], key,
 496             TCP_FASTOPEN_KEY_LEN);
 497         if (V_tcp_fastopen_numkeys < TCP_FASTOPEN_MAX_KEYS)
 498                 V_tcp_fastopen_numkeys++;
 499 }
 500
 501 static void
 502 tcp_fastopen_addpsk_locked(uint8_t *psk)
 503 {
 504
 505         V_tcp_fastopen_keys.newest_psk++;
 506         if (V_tcp_fastopen_keys.newest_psk == TCP_FASTOPEN_MAX_PSKS)
 507                 V_tcp_fastopen_keys.newest_psk = 0;
 508         memcpy(V_tcp_fastopen_keys.psk[V_tcp_fastopen_keys.newest_psk], psk,
 509             TCP_FASTOPEN_KEY_LEN);
 510         if (V_tcp_fastopen_numpsks < TCP_FASTOPEN_MAX_PSKS)
 511                 V_tcp_fastopen_numpsks++;
 512 }
 513
 514 static void
 515 tcp_fastopen_autokey_locked(void)
 516 {
 517         uint8_t newkey[TCP_FASTOPEN_KEY_LEN];
 518
 519         arc4rand(newkey, TCP_FASTOPEN_KEY_LEN, 0);
 520         tcp_fastopen_addkey_locked(newkey);
 521 }
 522
 523 static void
 524 tcp_fastopen_autokey_callout(void *arg)
 525 {
 526         struct tcp_fastopen_callout *ctx = arg;
 527
 528         CURVNET_SET(ctx->v);
 529         tcp_fastopen_autokey_locked();
 530         callout_reset(&ctx->c, V_tcp_fastopen_autokey * hz,
 531                       tcp_fastopen_autokey_callout, ctx);
 532         CURVNET_RESTORE();
 533 }
 534
 535
 536 static uint64_t
 537 tcp_fastopen_make_cookie(uint8_t key[SIPHASH_KEY_LENGTH], struct in_conninfo *inc)
 538 {
 539         SIPHASH_CTX ctx;
 540         uint64_t siphash;
 541
 542         SipHash24_Init(&ctx);
 543         SipHash_SetKey(&ctx, key);
 544         switch (inc->inc_flags & INC_ISIPV6) {
 545 #ifdef INET
 546         case 0:
 547                 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(inc->inc_faddr));
 548                 break;
 549 #endif
 550 #ifdef INET6
 551         case INC_ISIPV6:
 552                 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(inc->inc6_faddr));
 553                 break;
 554 #endif
 555         }
 556         SipHash_Final((u_int8_t *)&siphash, &ctx);
 557
 558         return (siphash);
 559 }
 560
 561 static uint64_t
 562 tcp_fastopen_make_psk_cookie(uint8_t *psk, uint8_t *cookie, uint8_t cookie_len)
 563 {
 564         SIPHASH_CTX ctx;
 565         uint64_t psk_cookie;
 566
 567         SipHash24_Init(&ctx);
 568         SipHash_SetKey(&ctx, psk);
 569         SipHash_Update(&ctx, cookie, cookie_len);
 570         SipHash_Final((u_int8_t *)&psk_cookie, &ctx);
 571
 572         return (psk_cookie);
 573 }
 574
 575 static int
 576 tcp_fastopen_find_cookie_match_locked(uint8_t *wire_cookie, uint64_t *cur_cookie)
 577 {
 578         unsigned int i, psk_index;
 579         uint64_t psk_cookie;
 580
 581         if (V_tcp_fastopen_psk_enable) {
 582                 psk_index = V_tcp_fastopen_keys.newest_psk;
 583                 for (i = 0; i < V_tcp_fastopen_numpsks; i++) {
 584                         psk_cookie =
 585                             tcp_fastopen_make_psk_cookie(
 586                                  V_tcp_fastopen_keys.psk[psk_index],
 587                                  (uint8_t *)cur_cookie,
 588                                  TCP_FASTOPEN_COOKIE_LEN);
 589
 590                         if (memcmp(wire_cookie, &psk_cookie,
 591                                    TCP_FASTOPEN_COOKIE_LEN) == 0)
 592                                 return (1);
 593
 594                         if (psk_index == 0)
 595                                 psk_index = TCP_FASTOPEN_MAX_PSKS - 1;
 596                         else
 597                                 psk_index--;
 598                 }
 599         } else if (memcmp(wire_cookie, cur_cookie, TCP_FASTOPEN_COOKIE_LEN) == 0)
 600                 return (1);
 601
 602         return (0);
 603 }
 604
 605 /*
 606  * Return values:
 607  *      -1      the cookie is invalid and no valid cookie is available
 608  *       0      the cookie is invalid and the latest cookie has been returned
 609  *       1      the cookie is valid and the latest cookie has been returned
 610  */
 611 int
 612 tcp_fastopen_check_cookie(struct in_conninfo *inc, uint8_t *cookie,
 613     unsigned int len, uint64_t *latest_cookie)
 614 {
 615         struct rm_priotracker tracker;
 616         unsigned int i, key_index;
 617         int rv;
 618         uint64_t cur_cookie;
 619
 620         if (V_tcp_fastopen_acceptany) {
 621                 *latest_cookie = 0;
 622                 return (1);
 623         }
 624
 625         TCP_FASTOPEN_KEYS_RLOCK(&tracker);
 626         if (len != TCP_FASTOPEN_COOKIE_LEN) {
 627                 if (V_tcp_fastopen_numkeys > 0) {
 628                         *latest_cookie =
 629                             tcp_fastopen_make_cookie(
 630                                 V_tcp_fastopen_keys.key[V_tcp_fastopen_keys.newest],
 631                                 inc);
 632                         rv = 0;
 633                 } else
 634                         rv = -1;
 635                 goto out;
 636         }
 637
 638         /*
 639          * Check against each available key, from newest to oldest.
 640          */
 641         key_index = V_tcp_fastopen_keys.newest;
 642         for (i = 0; i < V_tcp_fastopen_numkeys; i++) {
 643                 cur_cookie =
 644                     tcp_fastopen_make_cookie(V_tcp_fastopen_keys.key[key_index],
 645                         inc);
 646                 if (i == 0)
 647                         *latest_cookie = cur_cookie;
 648                 rv = tcp_fastopen_find_cookie_match_locked(cookie, &cur_cookie);
 649                 if (rv)
 650                         goto out;
 651                 if (key_index == 0)
 652                         key_index = TCP_FASTOPEN_MAX_KEYS - 1;
 653                 else
 654                         key_index--;
 655         }
 656         rv = 0;
 657
 658  out:
 659         TCP_FASTOPEN_KEYS_RUNLOCK(&tracker);
 660         return (rv);
 661 }
 662
 663 static int
 664 sysctl_net_inet_tcp_fastopen_autokey(SYSCTL_HANDLER_ARGS)
 665 {
 666         int error;
 667         unsigned int new;
 668
 669         new = V_tcp_fastopen_autokey;
 670         error = sysctl_handle_int(oidp, &new, 0, req);
 671         if (error == 0 && req->newptr) {
 672                 if (new > (INT_MAX / hz))
 673                         return (EINVAL);
 674
 675                 TCP_FASTOPEN_KEYS_WLOCK();
 676                 if (V_tcp_fastopen_server_enable) {
 677                         if (V_tcp_fastopen_autokey && !new)
 678                                 callout_stop(&V_tcp_fastopen_autokey_ctx.c);
 679                         else if (new)
 680                                 callout_reset(&V_tcp_fastopen_autokey_ctx.c,
 681                                     new * hz, tcp_fastopen_autokey_callout,
 682                                     &V_tcp_fastopen_autokey_ctx);
 683                 }
 684                 V_tcp_fastopen_autokey = new;
 685                 TCP_FASTOPEN_KEYS_WUNLOCK();
 686         }
 687
 688         return (error);
 689 }
 690
 691 static int
 692 sysctl_net_inet_tcp_fastopen_psk_enable(SYSCTL_HANDLER_ARGS)
 693 {
 694         int error;
 695         unsigned int new;
 696
 697         new = V_tcp_fastopen_psk_enable;
 698         error = sysctl_handle_int(oidp, &new, 0, req);
 699         if (error == 0 && req->newptr) {
 700                 if (V_tcp_fastopen_psk_enable && !new) {
 701                         /* enabled -> disabled */
 702                         TCP_FASTOPEN_KEYS_WLOCK();
 703                         V_tcp_fastopen_numpsks = 0;
 704                         V_tcp_fastopen_keys.newest_psk =
 705                             TCP_FASTOPEN_MAX_PSKS - 1;
 706                         V_tcp_fastopen_psk_enable = 0;
 707                         TCP_FASTOPEN_KEYS_WUNLOCK();
 708                 } else if (!V_tcp_fastopen_psk_enable && new) {
 709                         /* disabled -> enabled */
 710                         TCP_FASTOPEN_KEYS_WLOCK();
 711                         V_tcp_fastopen_psk_enable = 1;
 712                         TCP_FASTOPEN_KEYS_WUNLOCK();
 713                 }
 714         }
 715         return (error);
 716 }
 717
 718 static int
 719 sysctl_net_inet_tcp_fastopen_server_enable(SYSCTL_HANDLER_ARGS)
 720 {
 721         int error;
 722         unsigned int new;
 723
 724         new = V_tcp_fastopen_server_enable;
 725         error = sysctl_handle_int(oidp, &new, 0, req);
 726         if (error == 0 && req->newptr) {
 727                 if (V_tcp_fastopen_server_enable && !new) {
 728                         /* enabled -> disabled */
 729                         TCP_FASTOPEN_KEYS_WLOCK();
 730                         V_tcp_fastopen_numkeys = 0;
 731                         V_tcp_fastopen_keys.newest = TCP_FASTOPEN_MAX_KEYS - 1;
 732                         if (V_tcp_fastopen_autokey)
 733                                 callout_stop(&V_tcp_fastopen_autokey_ctx.c);
 734                         V_tcp_fastopen_numpsks = 0;
 735                         V_tcp_fastopen_keys.newest_psk =
 736                             TCP_FASTOPEN_MAX_PSKS - 1;
 737                         V_tcp_fastopen_server_enable = 0;
 738                         TCP_FASTOPEN_KEYS_WUNLOCK();
 739                 } else if (!V_tcp_fastopen_server_enable && new) {
 740                         /* disabled -> enabled */
 741                         TCP_FASTOPEN_KEYS_WLOCK();
 742                         if (V_tcp_fastopen_autokey &&
 743                             (V_tcp_fastopen_numkeys == 0)) {
 744                                 tcp_fastopen_autokey_locked();
 745                                 callout_reset(&V_tcp_fastopen_autokey_ctx.c,
 746                                     V_tcp_fastopen_autokey * hz,
 747                                     tcp_fastopen_autokey_callout,
 748                                     &V_tcp_fastopen_autokey_ctx);
 749                         }
 750                         V_tcp_fastopen_server_enable = 1;
 751                         TCP_FASTOPEN_KEYS_WUNLOCK();
 752                 }
 753         }
 754         return (error);
 755 }
 756
 757 static int
 758 sysctl_net_inet_tcp_fastopen_setkey(SYSCTL_HANDLER_ARGS)
 759 {
 760         int error;
 761         uint8_t newkey[TCP_FASTOPEN_KEY_LEN];
 762
 763         if (req->oldptr != NULL || req->oldlen != 0)
 764                 return (EINVAL);
 765         if (req->newptr == NULL)
 766                 return (EPERM);
 767         if (req->newlen != sizeof(newkey))
 768                 return (EINVAL);
 769         error = SYSCTL_IN(req, newkey, sizeof(newkey));
 770         if (error)
 771                 return (error);
 772
 773         TCP_FASTOPEN_KEYS_WLOCK();
 774         tcp_fastopen_addkey_locked(newkey);
 775         TCP_FASTOPEN_KEYS_WUNLOCK();
 776
 777         return (0);
 778 }
 779
 780 static int
 781 sysctl_net_inet_tcp_fastopen_setpsk(SYSCTL_HANDLER_ARGS)
 782 {
 783         int error;
 784         uint8_t newpsk[TCP_FASTOPEN_KEY_LEN];
 785
 786         if (req->oldptr != NULL || req->oldlen != 0)
 787                 return (EINVAL);
 788         if (req->newptr == NULL)
 789                 return (EPERM);
 790         if (req->newlen != sizeof(newpsk))
 791                 return (EINVAL);
 792         error = SYSCTL_IN(req, newpsk, sizeof(newpsk));
 793         if (error)
 794                 return (error);
 795
 796         TCP_FASTOPEN_KEYS_WLOCK();
 797         tcp_fastopen_addpsk_locked(newpsk);
 798         TCP_FASTOPEN_KEYS_WUNLOCK();
 799
 800         return (0);
 801 }
 802
 803 static int
 804 sysctl_net_inet_tcp_fastopen_ccache_bucket_limit(SYSCTL_HANDLER_ARGS)
 805 {
 806         struct tcp_fastopen_ccache_bucket *ccb;
 807         int error;
 808         unsigned int new;
 809         unsigned int i;
 810
 811         new = V_tcp_fastopen_ccache.bucket_limit;
 812         error = sysctl_handle_int(oidp, &new, 0, req);
 813         if (error == 0 && req->newptr) {
 814                 if ((new == 0) || (new > INT_MAX))
 815                         error = EINVAL;
 816                 else {
 817                         if (new < V_tcp_fastopen_ccache.bucket_limit) {
 818                                 for (i = 0; i < V_tcp_fastopen_ccache.buckets;
 819                                      i++) {
 820                                         ccb = &V_tcp_fastopen_ccache.base[i];
 821                                         tcp_fastopen_ccache_bucket_trim(ccb, new);
 822                                 }
 823                         }
 824                         V_tcp_fastopen_ccache.bucket_limit = new;
 825                 }
 826
 827         }
 828         return (error);
 829 }
 830
 831 static int
 832 sysctl_net_inet_tcp_fastopen_client_enable(SYSCTL_HANDLER_ARGS)
 833 {
 834         struct tcp_fastopen_ccache_bucket *ccb;
 835         int error;
 836         unsigned int new, i;
 837
 838         new = V_tcp_fastopen_client_enable;
 839         error = sysctl_handle_int(oidp, &new, 0, req);
 840         if (error == 0 && req->newptr) {
 841                 if (V_tcp_fastopen_client_enable && !new) {
 842                         /* enabled -> disabled */
 843                         for (i = 0; i < V_tcp_fastopen_ccache.buckets; i++) {
 844                                 ccb = &V_tcp_fastopen_ccache.base[i];
 845                                 KASSERT(ccb->ccb_num_entries > -1,
 846                                     ("%s: ccb->ccb_num_entries %d is negative",
 847                                         __func__, ccb->ccb_num_entries));
 848                                 tcp_fastopen_ccache_bucket_trim(ccb, 0);
 849                         }
 850                         V_tcp_fastopen_client_enable = 0;
 851                 } else if (!V_tcp_fastopen_client_enable && new) {
 852                         /* disabled -> enabled */
 853                         for (i = 0; i < V_tcp_fastopen_ccache.buckets; i++) {
 854                                 ccb = &V_tcp_fastopen_ccache.base[i];
 855                                 CCB_LOCK(ccb);
 856                                 KASSERT(TAILQ_EMPTY(&ccb->ccb_entries),
 857                                     ("%s: ccb->ccb_entries not empty", __func__));
 858                                 KASSERT(ccb->ccb_num_entries == -1,
 859                                     ("%s: ccb->ccb_num_entries %d not -1", __func__,
 860                                         ccb->ccb_num_entries));
 861                                 ccb->ccb_num_entries = 0; /* enable bucket */
 862                                 CCB_UNLOCK(ccb);
 863                         }
 864                         V_tcp_fastopen_client_enable = 1;
 865                 }
 866         }
 867         return (error);
 868 }
 869
 870 void
 871 tcp_fastopen_connect(struct tcpcb *tp)
 872 {
 873         struct inpcb *inp;
 874         struct tcp_fastopen_ccache_bucket *ccb;
 875         struct tcp_fastopen_ccache_entry *cce;
 876         sbintime_t now;
 877         uint16_t server_mss;
 878         uint64_t psk_cookie;
 879
 880         psk_cookie = 0;
 881         inp = tp->t_inpcb;
 882         cce = tcp_fastopen_ccache_lookup(&inp->inp_inc, &ccb);
 883         if (cce) {
 884                 if (cce->disable_time == 0) {
 885                         if ((cce->cookie_len > 0) &&
 886                             (tp->t_tfo_client_cookie_len ==
 887                              TCP_FASTOPEN_PSK_LEN)) {
 888                                 psk_cookie =
 889                                     tcp_fastopen_make_psk_cookie(
 890                                         tp->t_tfo_cookie.client,
 891                                         cce->cookie, cce->cookie_len);
 892                         } else {
 893                                 tp->t_tfo_client_cookie_len = cce->cookie_len;
 894                                 memcpy(tp->t_tfo_cookie.client, cce->cookie,
 895                                     cce->cookie_len);
 896                         }
 897                         server_mss = cce->server_mss;
 898                         CCB_UNLOCK(ccb);
 899                         if (tp->t_tfo_client_cookie_len ==
 900                             TCP_FASTOPEN_PSK_LEN && psk_cookie) {
 901                                 tp->t_tfo_client_cookie_len =
 902                                     TCP_FASTOPEN_COOKIE_LEN;
 903                                 memcpy(tp->t_tfo_cookie.client, &psk_cookie,
 904                                     TCP_FASTOPEN_COOKIE_LEN);
 905                         }
 906                         tcp_mss(tp, server_mss ? server_mss : -1);
 907                         tp->snd_wnd = tp->t_maxseg;
 908                 } else {
 909                         /*
 910                          * The path is disabled.  Check the time and
 911                          * possibly re-enable.
 912                          */
 913                         now = getsbinuptime();
 914                         if (now - cce->disable_time >
 915                             ((sbintime_t)V_tcp_fastopen_path_disable_time << 32)) {
 916                                 /*
 917                                  * Re-enable path.  Force a TFO cookie
 918                                  * request.  Forget the old MSS as it may be
 919                                  * bogus now, and we will rediscover it in
 920                                  * the SYN|ACK.
 921                                  */
 922                                 cce->disable_time = 0;
 923                                 cce->server_mss = 0;
 924                                 cce->cookie_len = 0;
 925                                 /*
 926                                  * tp->t_tfo... cookie details are already
 927                                  * zero from the tcpcb init.
 928                                  */
 929                         } else {
 930                                 /*
 931                                  * Path is disabled, so disable TFO on this
 932                                  * connection.
 933                                  */
 934                                 tp->t_flags &= ~TF_FASTOPEN;
 935                         }
 936                         CCB_UNLOCK(ccb);
 937                         tcp_mss(tp, -1);
 938                         /*
 939                          * snd_wnd is irrelevant since we are either forcing
 940                          * a TFO cookie request or disabling TFO - either
 941                          * way, no data with the SYN.
 942                          */
 943                 }
 944         } else {
 945                 /*
 946                  * A new entry for this path will be created when a SYN|ACK
 947                  * comes back, or the attempt otherwise fails.
 948                  */
 949                 CCB_UNLOCK(ccb);
 950                 tcp_mss(tp, -1);
 951                 /*
 952                  * snd_wnd is irrelevant since we are forcing a TFO cookie
 953                  * request.
 954                  */
 955         }
 956 }
 957
 958 void
 959 tcp_fastopen_disable_path(struct tcpcb *tp)
 960 {
 961         struct in_conninfo *inc = &tp->t_inpcb->inp_inc;
 962         struct tcp_fastopen_ccache_bucket *ccb;
 963         struct tcp_fastopen_ccache_entry *cce;
 964
 965         cce = tcp_fastopen_ccache_lookup(inc, &ccb);
 966         if (cce) {
 967                 cce->server_mss = 0;
 968                 cce->cookie_len = 0;
 969                 /*
 970                  * Preserve the existing disable time if it is already
 971                  * disabled.
 972                  */
 973                 if (cce->disable_time == 0)
 974                         cce->disable_time = getsbinuptime();
 975         } else /* use invalid cookie len to create disabled entry */
 976                 tcp_fastopen_ccache_create(ccb, inc, 0,
 977                     TCP_FASTOPEN_MAX_COOKIE_LEN + 1, NULL);
 978
 979         CCB_UNLOCK(ccb);
 980         tp->t_flags &= ~TF_FASTOPEN;
 981 }
 982
 983 void
 984 tcp_fastopen_update_cache(struct tcpcb *tp, uint16_t mss,
 985     uint8_t cookie_len, uint8_t *cookie)
 986 {
 987         struct in_conninfo *inc = &tp->t_inpcb->inp_inc;
 988         struct tcp_fastopen_ccache_bucket *ccb;
 989         struct tcp_fastopen_ccache_entry *cce;
 990
 991         cce = tcp_fastopen_ccache_lookup(inc, &ccb);
 992         if (cce) {
 993                 if ((cookie_len >= TCP_FASTOPEN_MIN_COOKIE_LEN) &&
 994                     (cookie_len <= TCP_FASTOPEN_MAX_COOKIE_LEN) &&
 995                     ((cookie_len & 0x1) == 0)) {
 996                         cce->server_mss = mss;
 997                         cce->cookie_len = cookie_len;
 998                         memcpy(cce->cookie, cookie, cookie_len);
 999                         cce->disable_time = 0;
1000                 } else {
1001                         /* invalid cookie length, disable entry */
1002                         cce->server_mss = 0;
1003                         cce->cookie_len = 0;
1004                         /*
1005                          * Preserve the existing disable time if it is
1006                          * already disabled.
1007                          */
1008                         if (cce->disable_time == 0)
1009                                 cce->disable_time = getsbinuptime();
1010                 }
1011         } else
1012                 tcp_fastopen_ccache_create(ccb, inc, mss, cookie_len, cookie);
1013
1014         CCB_UNLOCK(ccb);
1015 }
1016
1017 static struct tcp_fastopen_ccache_entry *
1018 tcp_fastopen_ccache_lookup(struct in_conninfo *inc,
1019     struct tcp_fastopen_ccache_bucket **ccbp)
1020 {
1021         struct tcp_fastopen_ccache_bucket *ccb;
1022         struct tcp_fastopen_ccache_entry *cce;
1023         uint32_t last_word;
1024         uint32_t hash;
1025
1026         hash = jenkins_hash32((uint32_t *)&inc->inc_ie.ie_dependladdr, 4,
1027             V_tcp_fastopen_ccache.secret);
1028         hash = jenkins_hash32((uint32_t *)&inc->inc_ie.ie_dependfaddr, 4,
1029             hash);
1030         last_word = inc->inc_fport;
1031         hash = jenkins_hash32(&last_word, 1, hash);
1032         ccb = &V_tcp_fastopen_ccache.base[hash & V_tcp_fastopen_ccache.mask];
1033         *ccbp = ccb;
1034         CCB_LOCK(ccb);
1035
1036         /*
1037          * Always returns with locked bucket.
1038          */
1039         TAILQ_FOREACH(cce, &ccb->ccb_entries, cce_link)
1040                 if ((!(cce->af == AF_INET6) == !(inc->inc_flags & INC_ISIPV6)) &&
1041                     (cce->server_port == inc->inc_ie.ie_fport) &&
1042                     (((cce->af == AF_INET) &&
1043                       (cce->cce_client_ip.v4.s_addr == inc->inc_laddr.s_addr) &&
1044                       (cce->cce_server_ip.v4.s_addr == inc->inc_faddr.s_addr)) ||
1045                      ((cce->af == AF_INET6) &&
1046                       IN6_ARE_ADDR_EQUAL(&cce->cce_client_ip.v6, &inc->inc6_laddr) &&
1047                       IN6_ARE_ADDR_EQUAL(&cce->cce_server_ip.v6, &inc->inc6_faddr))))
1048                         break;
1049
1050         return (cce);
1051 }
1052
1053 static struct tcp_fastopen_ccache_entry *
1054 tcp_fastopen_ccache_create(struct tcp_fastopen_ccache_bucket *ccb,
1055     struct in_conninfo *inc, uint16_t mss, uint8_t cookie_len, uint8_t *cookie)
1056 {
1057         struct tcp_fastopen_ccache_entry *cce;
1058
1059         /*
1060          * 1. Create a new entry, or
1061          * 2. Reclaim an existing entry, or
1062          * 3. Fail
1063          */
1064
1065         CCB_LOCK_ASSERT(ccb);
1066
1067         cce = NULL;
1068         if (ccb->ccb_num_entries < V_tcp_fastopen_ccache.bucket_limit)
1069                 cce = uma_zalloc(V_tcp_fastopen_ccache.zone, M_NOWAIT);
1070
1071         if (cce == NULL) {
1072                 /*
1073                  * At bucket limit, or out of memory - reclaim last
1074                  * entry in bucket.
1075                  */
1076                 cce = TAILQ_LAST(&ccb->ccb_entries, bucket_entries);
1077                 if (cce == NULL) {
1078                         /* XXX count this event */
1079                         return (NULL);
1080                 }
1081
1082                 TAILQ_REMOVE(&ccb->ccb_entries, cce, cce_link);
1083         } else
1084                 ccb->ccb_num_entries++;
1085
1086         TAILQ_INSERT_HEAD(&ccb->ccb_entries, cce, cce_link);
1087         cce->af = (inc->inc_flags & INC_ISIPV6) ? AF_INET6 : AF_INET;
1088         if (cce->af == AF_INET) {
1089                 cce->cce_client_ip.v4 = inc->inc_laddr;
1090                 cce->cce_server_ip.v4 = inc->inc_faddr;
1091         } else {
1092                 cce->cce_client_ip.v6 = inc->inc6_laddr;
1093                 cce->cce_server_ip.v6 = inc->inc6_faddr;
1094         }
1095         cce->server_port = inc->inc_fport;
1096         if ((cookie_len >= TCP_FASTOPEN_MIN_COOKIE_LEN) &&
1097             (cookie_len <= TCP_FASTOPEN_MAX_COOKIE_LEN) &&
1098             ((cookie_len & 0x1) == 0)) {
1099                 cce->server_mss = mss;
1100                 cce->cookie_len = cookie_len;
1101                 memcpy(cce->cookie, cookie, cookie_len);
1102                 cce->disable_time = 0;
1103         } else {
1104                 /* invalid cookie length, disable cce */
1105                 cce->server_mss = 0;
1106                 cce->cookie_len = 0;
1107                 cce->disable_time = getsbinuptime();
1108         }
1109
1110         return (cce);
1111 }
1112
1113 static void
1114 tcp_fastopen_ccache_bucket_trim(struct tcp_fastopen_ccache_bucket *ccb,
1115     unsigned int limit)
1116 {
1117         struct tcp_fastopen_ccache_entry *cce, *cce_tmp;
1118         unsigned int entries;
1119
1120         CCB_LOCK(ccb);
1121         entries = 0;
1122         TAILQ_FOREACH_SAFE(cce, &ccb->ccb_entries, cce_link, cce_tmp) {
1123                 entries++;
1124                 if (entries > limit)
1125                         tcp_fastopen_ccache_entry_drop(cce, ccb);
1126         }
1127         KASSERT(ccb->ccb_num_entries <= (int)limit,
1128             ("%s: ccb->ccb_num_entries %d exceeds limit %d", __func__,
1129                 ccb->ccb_num_entries, limit));
1130         if (limit == 0) {
1131                 KASSERT(TAILQ_EMPTY(&ccb->ccb_entries),
1132                     ("%s: ccb->ccb_entries not empty", __func__));
1133                 ccb->ccb_num_entries = -1; /* disable bucket */
1134         }
1135         CCB_UNLOCK(ccb);
1136 }
1137
1138 static void
1139 tcp_fastopen_ccache_entry_drop(struct tcp_fastopen_ccache_entry *cce,
1140     struct tcp_fastopen_ccache_bucket *ccb)
1141 {
1142
1143         CCB_LOCK_ASSERT(ccb);
1144
1145         TAILQ_REMOVE(&ccb->ccb_entries, cce, cce_link);
1146         ccb->ccb_num_entries--;
1147         uma_zfree(V_tcp_fastopen_ccache.zone, cce);
1148 }
1149
1150 static int
1151 sysctl_net_inet_tcp_fastopen_ccache_list(SYSCTL_HANDLER_ARGS)
1152 {
1153         struct sbuf sb;
1154         struct tcp_fastopen_ccache_bucket *ccb;
1155         struct tcp_fastopen_ccache_entry *cce;
1156         sbintime_t now, duration, limit;
1157         const int linesize = 128;
1158         int i, error, num_entries;
1159         unsigned int j;
1160 #ifdef INET6
1161         char clt_buf[INET6_ADDRSTRLEN], srv_buf[INET6_ADDRSTRLEN];
1162 #else
1163         char clt_buf[INET_ADDRSTRLEN], srv_buf[INET_ADDRSTRLEN];
1164 #endif
1165
1166         if (jailed_without_vnet(curthread->td_ucred) != 0)
1167                 return (EPERM);
1168
1169         /* Only allow root to read the client cookie cache */
1170         if (curthread->td_ucred->cr_uid != 0)
1171                 return (EPERM);
1172
1173         num_entries = 0;
1174         for (i = 0; i < V_tcp_fastopen_ccache.buckets; i++) {
1175                 ccb = &V_tcp_fastopen_ccache.base[i];
1176                 CCB_LOCK(ccb);
1177                 if (ccb->ccb_num_entries > 0)
1178                         num_entries += ccb->ccb_num_entries;
1179                 CCB_UNLOCK(ccb);
1180         }
1181         sbuf_new(&sb, NULL, linesize * (num_entries + 1), SBUF_INCLUDENUL);
1182
1183         sbuf_printf(&sb,
1184                     "\nLocal IP address     Remote IP address     Port   MSS"
1185                     " Disabled Cookie\n");
1186
1187         now = getsbinuptime();
1188         limit = (sbintime_t)V_tcp_fastopen_path_disable_time << 32;
1189         for (i = 0; i < V_tcp_fastopen_ccache.buckets; i++) {
1190                 ccb = &V_tcp_fastopen_ccache.base[i];
1191                 CCB_LOCK(ccb);
1192                 TAILQ_FOREACH(cce, &ccb->ccb_entries, cce_link) {
1193                         if (cce->disable_time != 0) {
1194                                 duration = now - cce->disable_time;
1195                                 if (limit >= duration)
1196                                         duration = limit - duration;
1197                                 else
1198                                         duration = 0;
1199                         } else
1200                                 duration = 0;
1201                         sbuf_printf(&sb,
1202                                     "%-20s %-20s %5u %5u ",
1203                                     inet_ntop(cce->af, &cce->cce_client_ip,
1204                                         clt_buf, sizeof(clt_buf)),
1205                                     inet_ntop(cce->af, &cce->cce_server_ip,
1206                                         srv_buf, sizeof(srv_buf)),
1207                                     ntohs(cce->server_port),
1208                                     cce->server_mss);
1209                         if (duration > 0)
1210                                 sbuf_printf(&sb, "%7ds ", sbintime_getsec(duration));
1211                         else
1212                                 sbuf_printf(&sb, "%8s ", "No");
1213                         for (j = 0; j < cce->cookie_len; j++)
1214                                 sbuf_printf(&sb, "%02x", cce->cookie[j]);
1215                         sbuf_putc(&sb, '\n');
1216                 }
1217                 CCB_UNLOCK(ccb);
1218         }
1219         error = sbuf_finish(&sb);
1220         if (error == 0)
1221                 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
1222         sbuf_delete(&sb);
1223         return (error);
1224 }
1225