sys/netipsec/ipsec_pcb.c

   1 /*-
   2  * Copyright (c) 2016 Andrey V. Elsukov <ae@FreeBSD.org>
   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  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  30 #include "opt_inet.h"
  31 #include "opt_inet6.h"
  32 #include "opt_ipsec.h"
  33
  34 #include <sys/param.h>
  35 #include <sys/systm.h>
  36 #include <sys/kernel.h>
  37 #include <sys/lock.h>
  38 #include <sys/malloc.h>
  39 #include <sys/mbuf.h>
  40 #include <sys/priv.h>
  41 #include <sys/socket.h>
  42 #include <sys/sockopt.h>
  43 #include <sys/syslog.h>
  44 #include <sys/proc.h>
  45
  46 #include <netinet/in.h>
  47 #include <netinet/in_pcb.h>
  48
  49 #include <netipsec/ipsec.h>
  50 #include <netipsec/ipsec6.h>
  51 #include <netipsec/ipsec_support.h>
  52 #include <netipsec/key.h>
  53 #include <netipsec/key_debug.h>
  54
  55 MALLOC_DEFINE(M_IPSEC_INPCB, "inpcbpolicy", "inpcb-resident ipsec policy");
  56
  57 static void
  58 ipsec_setsockaddrs_inpcb(struct inpcb *inp, union sockaddr_union *src,
  59     union sockaddr_union *dst, u_int dir)
  60 {
  61
  62 #ifdef INET6
  63         if (inp->inp_vflag & INP_IPV6) {
  64                 struct sockaddr_in6 *sin6;
  65
  66                 bzero(&src->sin6, sizeof(src->sin6));
  67                 bzero(&dst->sin6, sizeof(dst->sin6));
  68                 src->sin6.sin6_family = AF_INET6;
  69                 src->sin6.sin6_len = sizeof(struct sockaddr_in6);
  70                 dst->sin6.sin6_family = AF_INET6;
  71                 dst->sin6.sin6_len = sizeof(struct sockaddr_in6);
  72
  73                 if (dir == IPSEC_DIR_OUTBOUND)
  74                         sin6 = &src->sin6;
  75                 else
  76                         sin6 = &dst->sin6;
  77                 sin6->sin6_addr = inp->in6p_laddr;
  78                 sin6->sin6_port = inp->inp_lport;
  79                 if (IN6_IS_SCOPE_LINKLOCAL(&inp->in6p_laddr)) {
  80                         /* XXXAE: use in6p_zoneid */
  81                         sin6->sin6_addr.s6_addr16[1] = 0;
  82                         sin6->sin6_scope_id = ntohs(
  83                             inp->in6p_laddr.s6_addr16[1]);
  84                 }
  85
  86                 if (dir == IPSEC_DIR_OUTBOUND)
  87                         sin6 = &dst->sin6;
  88                 else
  89                         sin6 = &src->sin6;
  90                 sin6->sin6_addr = inp->in6p_faddr;
  91                 sin6->sin6_port = inp->inp_fport;
  92                 if (IN6_IS_SCOPE_LINKLOCAL(&inp->in6p_faddr)) {
  93                         /* XXXAE: use in6p_zoneid */
  94                         sin6->sin6_addr.s6_addr16[1] = 0;
  95                         sin6->sin6_scope_id = ntohs(
  96                             inp->in6p_faddr.s6_addr16[1]);
  97                 }
  98         }
  99 #endif
 100 #ifdef INET
 101         if (inp->inp_vflag & INP_IPV4) {
 102                 struct sockaddr_in *sin;
 103
 104                 bzero(&src->sin, sizeof(src->sin));
 105                 bzero(&dst->sin, sizeof(dst->sin));
 106                 src->sin.sin_family = AF_INET;
 107                 src->sin.sin_len = sizeof(struct sockaddr_in);
 108                 dst->sin.sin_family = AF_INET;
 109                 dst->sin.sin_len = sizeof(struct sockaddr_in);
 110
 111                 if (dir == IPSEC_DIR_OUTBOUND)
 112                         sin = &src->sin;
 113                 else
 114                         sin = &dst->sin;
 115                 sin->sin_addr = inp->inp_laddr;
 116                 sin->sin_port = inp->inp_lport;
 117
 118                 if (dir == IPSEC_DIR_OUTBOUND)
 119                         sin = &dst->sin;
 120                 else
 121                         sin = &src->sin;
 122                 sin->sin_addr = inp->inp_faddr;
 123                 sin->sin_port = inp->inp_fport;
 124         }
 125 #endif
 126 }
 127
 128 void
 129 ipsec_setspidx_inpcb(struct inpcb *inp, struct secpolicyindex *spidx,
 130     u_int dir)
 131 {
 132
 133         ipsec_setsockaddrs_inpcb(inp, &spidx->src, &spidx->dst, dir);
 134 #ifdef INET6
 135         if (inp->inp_vflag & INP_IPV6) {
 136                 spidx->prefs = sizeof(struct in6_addr) << 3;
 137                 spidx->prefd = sizeof(struct in6_addr) << 3;
 138         }
 139 #endif
 140 #ifdef INET
 141         if (inp->inp_vflag & INP_IPV4) {
 142                 spidx->prefs = sizeof(struct in_addr) << 3;
 143                 spidx->prefd = sizeof(struct in_addr) << 3;
 144         }
 145 #endif
 146         spidx->ul_proto = IPPROTO_TCP; /* XXX: currently only TCP uses this */
 147         spidx->dir = dir;
 148         KEYDBG(IPSEC_DUMP,
 149             printf("%s: ", __func__); kdebug_secpolicyindex(spidx, NULL));
 150 }
 151
 152 /* Initialize PCB policy. */
 153 int
 154 ipsec_init_pcbpolicy(struct inpcb *inp)
 155 {
 156
 157         IPSEC_ASSERT(inp != NULL, ("null inp"));
 158         IPSEC_ASSERT(inp->inp_sp == NULL, ("inp_sp already initialized"));
 159
 160         inp->inp_sp = malloc(sizeof(struct inpcbpolicy), M_IPSEC_INPCB,
 161             M_NOWAIT | M_ZERO);
 162         if (inp->inp_sp == NULL)
 163                 return (ENOBUFS);
 164         return (0);
 165 }
 166
 167 /* Delete PCB policy. */
 168 int
 169 ipsec_delete_pcbpolicy(struct inpcb *inp)
 170 {
 171
 172         if (inp->inp_sp == NULL)
 173                 return (0);
 174
 175         if (inp->inp_sp->flags & INP_INBOUND_POLICY)
 176                 key_freesp(&inp->inp_sp->sp_in);
 177
 178         if (inp->inp_sp->flags & INP_OUTBOUND_POLICY)
 179                 key_freesp(&inp->inp_sp->sp_out);
 180
 181         free(inp->inp_sp, M_IPSEC_INPCB);
 182         inp->inp_sp = NULL;
 183         return (0);
 184 }
 185
 186 /* Deep-copy a policy in PCB. */
 187 static struct secpolicy *
 188 ipsec_deepcopy_pcbpolicy(struct secpolicy *src)
 189 {
 190         struct secpolicy *dst;
 191         int i;
 192
 193         if (src == NULL)
 194                 return (NULL);
 195
 196         IPSEC_ASSERT(src->state == IPSEC_SPSTATE_PCB, ("SP isn't PCB"));
 197
 198         dst = key_newsp();
 199         if (dst == NULL)
 200                 return (NULL);
 201
 202         /* spidx is not copied here */
 203         dst->policy = src->policy;
 204         dst->state = src->state;
 205         dst->priority = src->priority;
 206         /* Do not touch the refcnt field. */
 207
 208         /* Copy IPsec request chain. */
 209         for (i = 0; i < src->tcount; i++) {
 210                 dst->req[i] = ipsec_newisr();
 211                 if (dst->req[i] == NULL) {
 212                         key_freesp(&dst);
 213                         return (NULL);
 214                 }
 215                 bcopy(src->req[i], dst->req[i], sizeof(struct ipsecrequest));
 216                 dst->tcount++;
 217         }
 218         KEYDBG(IPSEC_DUMP,
 219             printf("%s: copied SP(%p) -> SP(%p)\n", __func__, src, dst);
 220             kdebug_secpolicy(dst));
 221         return (dst);
 222 }
 223
 224 /*
 225  * Copy IPsec policy from old INPCB into new.
 226  * It is expected that new INPCB has not configured policies.
 227  */
 228 int
 229 ipsec_copy_pcbpolicy(struct inpcb *old, struct inpcb *new)
 230 {
 231         struct secpolicy *sp;
 232
 233         /*
 234          * old->inp_sp can be NULL if PCB was created when an IPsec
 235          * support was unavailable. This is not an error, we don't have
 236          * policies in this PCB, so nothing to copy.
 237          */
 238         if (old->inp_sp == NULL)
 239                 return (0);
 240
 241         IPSEC_ASSERT(new->inp_sp != NULL, ("new inp_sp is NULL"));
 242         IPSEC_ASSERT((new->inp_sp->flags & (
 243             INP_INBOUND_POLICY | INP_OUTBOUND_POLICY)) == 0,
 244             ("new PCB already has configured policies"));
 245         INP_WLOCK_ASSERT(new);
 246         INP_LOCK_ASSERT(old);
 247
 248         if (old->inp_sp->flags & INP_INBOUND_POLICY) {
 249                 sp = ipsec_deepcopy_pcbpolicy(old->inp_sp->sp_in);
 250                 if (sp == NULL)
 251                         return (ENOBUFS);
 252                 ipsec_setspidx_inpcb(new, &sp->spidx, IPSEC_DIR_INBOUND);
 253                 new->inp_sp->sp_in = sp;
 254                 new->inp_sp->flags |= INP_INBOUND_POLICY;
 255         }
 256         if (old->inp_sp->flags & INP_OUTBOUND_POLICY) {
 257                 sp = ipsec_deepcopy_pcbpolicy(old->inp_sp->sp_out);
 258                 if (sp == NULL)
 259                         return (ENOBUFS);
 260                 ipsec_setspidx_inpcb(new, &sp->spidx, IPSEC_DIR_OUTBOUND);
 261                 new->inp_sp->sp_out = sp;
 262                 new->inp_sp->flags |= INP_OUTBOUND_POLICY;
 263         }
 264         return (0);
 265 }
 266
 267 static int
 268 ipsec_set_pcbpolicy(struct inpcb *inp, struct ucred *cred,
 269     void *request, size_t len)
 270 {
 271         struct sadb_x_policy *xpl;
 272         struct secpolicy **spp, *newsp;
 273         int error, flags;
 274
 275         xpl = (struct sadb_x_policy *)request;
 276         /* Select direction. */
 277         switch (xpl->sadb_x_policy_dir) {
 278         case IPSEC_DIR_INBOUND:
 279         case IPSEC_DIR_OUTBOUND:
 280                 break;
 281         default:
 282                 ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__,
 283                         xpl->sadb_x_policy_dir));
 284                 return (EINVAL);
 285         }
 286         /*
 287          * Privileged sockets are allowed to set own security policy
 288          * and configure IPsec bypass. Unprivileged sockets only can
 289          * have ENTRUST policy.
 290          */
 291         switch (xpl->sadb_x_policy_type) {
 292         case IPSEC_POLICY_IPSEC:
 293         case IPSEC_POLICY_BYPASS:
 294                 if (cred != NULL &&
 295                     priv_check_cred(cred, PRIV_NETINET_IPSEC, 0) != 0)
 296                         return (EACCES);
 297                 /* Allocate new SP entry. */
 298                 newsp = key_msg2sp(xpl, len, &error);
 299                 if (newsp == NULL)
 300                         return (error);
 301                 newsp->state = IPSEC_SPSTATE_PCB;
 302                 newsp->spidx.ul_proto = IPSEC_ULPROTO_ANY;
 303 #ifdef INET
 304                 if (inp->inp_vflag & INP_IPV4) {
 305                         newsp->spidx.src.sin.sin_family =
 306                             newsp->spidx.dst.sin.sin_family = AF_INET;
 307                         newsp->spidx.src.sin.sin_len =
 308                             newsp->spidx.dst.sin.sin_len =
 309                             sizeof(struct sockaddr_in);
 310                 }
 311 #endif
 312 #ifdef INET6
 313                 if (inp->inp_vflag & INP_IPV6) {
 314                         newsp->spidx.src.sin6.sin6_family =
 315                             newsp->spidx.dst.sin6.sin6_family = AF_INET6;
 316                         newsp->spidx.src.sin6.sin6_len =
 317                             newsp->spidx.dst.sin6.sin6_len =
 318                             sizeof(struct sockaddr_in6);
 319                 }
 320 #endif
 321                 break;
 322         case IPSEC_POLICY_ENTRUST:
 323                 /* We just use NULL pointer for ENTRUST policy */
 324                 newsp = NULL;
 325                 break;
 326         default:
 327                 /* Other security policy types aren't allowed for PCB */
 328                 return (EINVAL);
 329         }
 330
 331         INP_WLOCK(inp);
 332         if (xpl->sadb_x_policy_dir == IPSEC_DIR_INBOUND) {
 333                 spp = &inp->inp_sp->sp_in;
 334                 flags = INP_INBOUND_POLICY;
 335         } else {
 336                 spp = &inp->inp_sp->sp_out;
 337                 flags = INP_OUTBOUND_POLICY;
 338         }
 339         /* Clear old SP and set new SP. */
 340         if (*spp != NULL)
 341                 key_freesp(spp);
 342         *spp = newsp;
 343         KEYDBG(IPSEC_DUMP,
 344             printf("%s: new SP(%p)\n", __func__, newsp));
 345         if (newsp == NULL)
 346                 inp->inp_sp->flags &= ~flags;
 347         else {
 348                 inp->inp_sp->flags |= flags;
 349                 KEYDBG(IPSEC_DUMP, kdebug_secpolicy(newsp));
 350         }
 351         INP_WUNLOCK(inp);
 352         return (0);
 353 }
 354
 355 static int
 356 ipsec_get_pcbpolicy(struct inpcb *inp, void *request, size_t *len)
 357 {
 358         struct sadb_x_policy *xpl;
 359         struct secpolicy *sp;
 360         int error, flags;
 361
 362         xpl = (struct sadb_x_policy *)request;
 363
 364         INP_RLOCK(inp);
 365         flags = inp->inp_sp->flags;
 366         /* Select direction. */
 367         switch (xpl->sadb_x_policy_dir) {
 368         case IPSEC_DIR_INBOUND:
 369                 sp = inp->inp_sp->sp_in;
 370                 flags &= INP_INBOUND_POLICY;
 371                 break;
 372         case IPSEC_DIR_OUTBOUND:
 373                 sp = inp->inp_sp->sp_out;
 374                 flags &= INP_OUTBOUND_POLICY;
 375                 break;
 376         default:
 377                 INP_RUNLOCK(inp);
 378                 ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__,
 379                         xpl->sadb_x_policy_dir));
 380                 return (EINVAL);
 381         }
 382
 383         if (flags == 0) {
 384                 /* Return ENTRUST policy */
 385                 INP_RUNLOCK(inp);
 386                 xpl->sadb_x_policy_exttype = SADB_X_EXT_POLICY;
 387                 xpl->sadb_x_policy_type = IPSEC_POLICY_ENTRUST;
 388                 xpl->sadb_x_policy_id = 0;
 389                 xpl->sadb_x_policy_priority = 0;
 390                 xpl->sadb_x_policy_len = PFKEY_UNIT64(sizeof(*xpl));
 391                 *len = sizeof(*xpl);
 392                 return (0);
 393         }
 394
 395         IPSEC_ASSERT(sp != NULL,
 396             ("sp is NULL, but flags is 0x%04x", inp->inp_sp->flags));
 397
 398         key_addref(sp);
 399         INP_RUNLOCK(inp);
 400         error = key_sp2msg(sp, request, len);
 401         key_freesp(&sp);
 402         if (error == EINVAL)
 403                 return (error);
 404         /*
 405          * We return "success", but user should check *len.
 406          * *len will be set to size of valid data and
 407          * sadb_x_policy_len will contain needed size.
 408          */
 409         return (0);
 410 }
 411
 412 /* Handle socket option control request for PCB */
 413 static int
 414 ipsec_control_pcbpolicy(struct inpcb *inp, struct sockopt *sopt)
 415 {
 416         void *optdata;
 417         size_t optlen;
 418         int error;
 419
 420         if (inp->inp_sp == NULL)
 421                 return (ENOPROTOOPT);
 422
 423         /* Limit maximum request size to PAGE_SIZE */
 424         optlen = sopt->sopt_valsize;
 425         if (optlen < sizeof(struct sadb_x_policy) || optlen > PAGE_SIZE)
 426                 return (EINVAL);
 427
 428         optdata = malloc(optlen, M_TEMP, sopt->sopt_td ? M_WAITOK: M_NOWAIT);
 429         if (optdata == NULL)
 430                 return (ENOBUFS);
 431         /*
 432          * We need a hint from the user, what policy is requested - input
 433          * or output? User should specify it in the buffer, even for
 434          * setsockopt().
 435          */
 436         error = sooptcopyin(sopt, optdata, optlen, optlen);
 437         if (error == 0) {
 438                 if (sopt->sopt_dir == SOPT_SET)
 439                         error = ipsec_set_pcbpolicy(inp,
 440                             sopt->sopt_td ? sopt->sopt_td->td_ucred: NULL,
 441                             optdata, optlen);
 442                 else {
 443                         error = ipsec_get_pcbpolicy(inp, optdata, &optlen);
 444                         if (error == 0)
 445                                 error = sooptcopyout(sopt, optdata, optlen);
 446                 }
 447         }
 448         free(optdata, M_TEMP);
 449         return (error);
 450 }
 451
 452 #ifdef INET
 453 /*
 454  * IPSEC_PCBCTL() method implementation for IPv4.
 455  */
 456 int
 457 ipsec4_pcbctl(struct inpcb *inp, struct sockopt *sopt)
 458 {
 459
 460         if (sopt->sopt_name != IP_IPSEC_POLICY)
 461                 return (ENOPROTOOPT);
 462         return (ipsec_control_pcbpolicy(inp, sopt));
 463 }
 464 #endif
 465
 466 #ifdef INET6
 467 /*
 468  * IPSEC_PCBCTL() method implementation for IPv6.
 469  */
 470 int
 471 ipsec6_pcbctl(struct inpcb *inp, struct sockopt *sopt)
 472 {
 473
 474         if (sopt->sopt_name != IPV6_IPSEC_POLICY)
 475                 return (ENOPROTOOPT);
 476         return (ipsec_control_pcbpolicy(inp, sopt));
 477 }
 478 #endif
 479