net/xfrm/xfrm_user.c

   1 /* xfrm_user.c: User interface to configure xfrm engine.
   2  *
   3  * Copyright (C) 2002 David S. Miller (davem@redhat.com)
   4  *
   5  * Changes:
   6  *      Mitsuru KANDA @USAGI
   7  *      Kazunori MIYAZAWA @USAGI
   8  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   9  *              IPv6 support
  10  *
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/types.h>
  16 #include <linux/slab.h>
  17 #include <linux/socket.h>
  18 #include <linux/string.h>
  19 #include <linux/net.h>
  20 #include <linux/skbuff.h>
  21 #include <linux/netlink.h>
  22 #include <linux/rtnetlink.h>
  23 #include <linux/pfkeyv2.h>
  24 #include <linux/ipsec.h>
  25 #include <linux/init.h>
  26 #include <linux/security.h>
  27 #include <net/sock.h>
  28 #include <net/xfrm.h>
  29 #include <asm/uaccess.h>
  30
  31 static struct sock *xfrm_nl;
  32
  33 static int verify_one_alg(struct rtattr **xfrma, enum xfrm_attr_type_t type)
  34 {
  35         struct rtattr *rt = xfrma[type - 1];
  36         struct xfrm_algo *algp;
  37         int len;
  38
  39         if (!rt)
  40                 return 0;
  41
  42         len = (rt->rta_len - sizeof(*rt)) - sizeof(*algp);
  43         if (len < 0)
  44                 return -EINVAL;
  45
  46         algp = RTA_DATA(rt);
  47
  48         len -= (algp->alg_key_len + 7U) / 8;
  49         if (len < 0)
  50                 return -EINVAL;
  51
  52         switch (type) {
  53         case XFRMA_ALG_AUTH:
  54                 if (!algp->alg_key_len &&
  55                     strcmp(algp->alg_name, "digest_null") != 0)
  56                         return -EINVAL;
  57                 break;
  58
  59         case XFRMA_ALG_CRYPT:
  60                 if (!algp->alg_key_len &&
  61                     strcmp(algp->alg_name, "cipher_null") != 0)
  62                         return -EINVAL;
  63                 break;
  64
  65         case XFRMA_ALG_COMP:
  66                 /* Zero length keys are legal.  */
  67                 break;
  68
  69         default:
  70                 return -EINVAL;
  71         };
  72
  73         algp->alg_name[CRYPTO_MAX_ALG_NAME - 1] = '\0';
  74         return 0;
  75 }
  76
  77 static int verify_encap_tmpl(struct rtattr **xfrma)
  78 {
  79         struct rtattr *rt = xfrma[XFRMA_ENCAP - 1];
  80         struct xfrm_encap_tmpl *encap;
  81
  82         if (!rt)
  83                 return 0;
  84
  85         if ((rt->rta_len - sizeof(*rt)) < sizeof(*encap))
  86                 return -EINVAL;
  87
  88         return 0;
  89 }
  90
  91 static int verify_newsa_info(struct xfrm_usersa_info *p,
  92                              struct rtattr **xfrma)
  93 {
  94         int err;
  95
  96         err = -EINVAL;
  97         switch (p->family) {
  98         case AF_INET:
  99                 break;
 100
 101         case AF_INET6:
 102 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 103                 break;
 104 #else
 105                 err = -EAFNOSUPPORT;
 106                 goto out;
 107 #endif
 108
 109         default:
 110                 goto out;
 111         };
 112
 113         err = -EINVAL;
 114         switch (p->id.proto) {
 115         case IPPROTO_AH:
 116                 if (!xfrma[XFRMA_ALG_AUTH-1]    ||
 117                     xfrma[XFRMA_ALG_CRYPT-1]    ||
 118                     xfrma[XFRMA_ALG_COMP-1])
 119                         goto out;
 120                 break;
 121
 122         case IPPROTO_ESP:
 123                 if ((!xfrma[XFRMA_ALG_AUTH-1] &&
 124                      !xfrma[XFRMA_ALG_CRYPT-1]) ||
 125                     xfrma[XFRMA_ALG_COMP-1])
 126                         goto out;
 127                 break;
 128
 129         case IPPROTO_COMP:
 130                 if (!xfrma[XFRMA_ALG_COMP-1]    ||
 131                     xfrma[XFRMA_ALG_AUTH-1]     ||
 132                     xfrma[XFRMA_ALG_CRYPT-1])
 133                         goto out;
 134                 break;
 135
 136         default:
 137                 goto out;
 138         };
 139
 140         if ((err = verify_one_alg(xfrma, XFRMA_ALG_AUTH)))
 141                 goto out;
 142         if ((err = verify_one_alg(xfrma, XFRMA_ALG_CRYPT)))
 143                 goto out;
 144         if ((err = verify_one_alg(xfrma, XFRMA_ALG_COMP)))
 145                 goto out;
 146         if ((err = verify_encap_tmpl(xfrma)))
 147                 goto out;
 148
 149         err = -EINVAL;
 150         switch (p->mode) {
 151         case 0:
 152         case 1:
 153                 break;
 154
 155         default:
 156                 goto out;
 157         };
 158
 159         err = 0;
 160
 161 out:
 162         return err;
 163 }
 164
 165 static int attach_one_algo(struct xfrm_algo **algpp, u8 *props,
 166                            struct xfrm_algo_desc *(*get_byname)(char *, int),
 167                            struct rtattr *u_arg)
 168 {
 169         struct rtattr *rta = u_arg;
 170         struct xfrm_algo *p, *ualg;
 171         struct xfrm_algo_desc *algo;
 172         int len;
 173
 174         if (!rta)
 175                 return 0;
 176
 177         ualg = RTA_DATA(rta);
 178
 179         algo = get_byname(ualg->alg_name, 1);
 180         if (!algo)
 181                 return -ENOSYS;
 182         *props = algo->desc.sadb_alg_id;
 183
 184         len = sizeof(*ualg) + (ualg->alg_key_len + 7U) / 8;
 185         p = kmalloc(len, GFP_KERNEL);
 186         if (!p)
 187                 return -ENOMEM;
 188
 189         memcpy(p, ualg, len);
 190         *algpp = p;
 191         return 0;
 192 }
 193
 194 static int attach_encap_tmpl(struct xfrm_encap_tmpl **encapp, struct rtattr *u_arg)
 195 {
 196         struct rtattr *rta = u_arg;
 197         struct xfrm_encap_tmpl *p, *uencap;
 198
 199         if (!rta)
 200                 return 0;
 201
 202         uencap = RTA_DATA(rta);
 203         p = kmalloc(sizeof(*p), GFP_KERNEL);
 204         if (!p)
 205                 return -ENOMEM;
 206
 207         memcpy(p, uencap, sizeof(*p));
 208         *encapp = p;
 209         return 0;
 210 }
 211
 212 static void copy_from_user_state(struct xfrm_state *x, struct xfrm_usersa_info *p)
 213 {
 214         memcpy(&x->id, &p->id, sizeof(x->id));
 215         memcpy(&x->sel, &p->sel, sizeof(x->sel));
 216         memcpy(&x->lft, &p->lft, sizeof(x->lft));
 217         x->props.mode = p->mode;
 218         x->props.replay_window = p->replay_window;
 219         x->props.reqid = p->reqid;
 220         x->props.family = p->family;
 221         x->props.saddr = p->saddr;
 222         x->props.flags = p->flags;
 223 }
 224
 225 static struct xfrm_state *xfrm_state_construct(struct xfrm_usersa_info *p,
 226                                                struct rtattr **xfrma,
 227                                                int *errp)
 228 {
 229         struct xfrm_state *x = xfrm_state_alloc();
 230         int err = -ENOMEM;
 231
 232         if (!x)
 233                 goto error_no_put;
 234
 235         copy_from_user_state(x, p);
 236
 237         if ((err = attach_one_algo(&x->aalg, &x->props.aalgo,
 238                                    xfrm_aalg_get_byname,
 239                                    xfrma[XFRMA_ALG_AUTH-1])))
 240                 goto error;
 241         if ((err = attach_one_algo(&x->ealg, &x->props.ealgo,
 242                                    xfrm_ealg_get_byname,
 243                                    xfrma[XFRMA_ALG_CRYPT-1])))
 244                 goto error;
 245         if ((err = attach_one_algo(&x->calg, &x->props.calgo,
 246                                    xfrm_calg_get_byname,
 247                                    xfrma[XFRMA_ALG_COMP-1])))
 248                 goto error;
 249         if ((err = attach_encap_tmpl(&x->encap, xfrma[XFRMA_ENCAP-1])))
 250                 goto error;
 251
 252         err = -ENOENT;
 253         x->type = xfrm_get_type(x->id.proto, x->props.family);
 254         if (x->type == NULL)
 255                 goto error;
 256
 257         err = x->type->init_state(x, NULL);
 258         if (err)
 259                 goto error;
 260
 261         x->curlft.add_time = (unsigned long) xtime.tv_sec;
 262         x->km.state = XFRM_STATE_VALID;
 263         x->km.seq = p->seq;
 264
 265         return x;
 266
 267 error:
 268         x->km.state = XFRM_STATE_DEAD;
 269         xfrm_state_put(x);
 270 error_no_put:
 271         *errp = err;
 272         return NULL;
 273 }
 274
 275 static int xfrm_add_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 276 {
 277         struct xfrm_usersa_info *p = NLMSG_DATA(nlh);
 278         struct xfrm_state *x;
 279         int err;
 280
 281         err = verify_newsa_info(p, (struct rtattr **) xfrma);
 282         if (err)
 283                 return err;
 284
 285         x = xfrm_state_construct(p, (struct rtattr **) xfrma, &err);
 286         if (!x)
 287                 return err;
 288
 289         if (nlh->nlmsg_type == XFRM_MSG_NEWSA)
 290                 err = xfrm_state_add(x);
 291         else
 292                 err = xfrm_state_update(x);
 293
 294         if (err < 0) {
 295                 x->km.state = XFRM_STATE_DEAD;
 296                 xfrm_state_put(x);
 297         }
 298
 299         return err;
 300 }
 301
 302 static int xfrm_del_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 303 {
 304         struct xfrm_state *x;
 305         struct xfrm_usersa_id *p = NLMSG_DATA(nlh);
 306
 307         x = xfrm_state_lookup(&p->daddr, p->spi, p->proto, p->family);
 308         if (x == NULL)
 309                 return -ESRCH;
 310
 311         if (xfrm_state_kern(x)) {
 312                 xfrm_state_put(x);
 313                 return -EPERM;
 314         }
 315
 316         xfrm_state_delete(x);
 317         xfrm_state_put(x);
 318
 319         return 0;
 320 }
 321
 322 static void copy_to_user_state(struct xfrm_state *x, struct xfrm_usersa_info *p)
 323 {
 324         memcpy(&p->id, &x->id, sizeof(p->id));
 325         memcpy(&p->sel, &x->sel, sizeof(p->sel));
 326         memcpy(&p->lft, &x->lft, sizeof(p->lft));
 327         memcpy(&p->curlft, &x->curlft, sizeof(p->curlft));
 328         memcpy(&p->stats, &x->stats, sizeof(p->stats));
 329         p->saddr = x->props.saddr;
 330         p->mode = x->props.mode;
 331         p->replay_window = x->props.replay_window;
 332         p->reqid = x->props.reqid;
 333         p->family = x->props.family;
 334         p->flags = x->props.flags;
 335         p->seq = x->km.seq;
 336 }
 337
 338 struct xfrm_dump_info {
 339         struct sk_buff *in_skb;
 340         struct sk_buff *out_skb;
 341         u32 nlmsg_seq;
 342         u16 nlmsg_flags;
 343         int start_idx;
 344         int this_idx;
 345 };
 346
 347 static int dump_one_state(struct xfrm_state *x, int count, void *ptr)
 348 {
 349         struct xfrm_dump_info *sp = ptr;
 350         struct sk_buff *in_skb = sp->in_skb;
 351         struct sk_buff *skb = sp->out_skb;
 352         struct xfrm_usersa_info *p;
 353         struct nlmsghdr *nlh;
 354         unsigned char *b = skb->tail;
 355
 356         if (sp->this_idx < sp->start_idx)
 357                 goto out;
 358
 359         nlh = NLMSG_PUT(skb, NETLINK_CB(in_skb).pid,
 360                         sp->nlmsg_seq,
 361                         XFRM_MSG_NEWSA, sizeof(*p));
 362         nlh->nlmsg_flags = sp->nlmsg_flags;
 363
 364         p = NLMSG_DATA(nlh);
 365         copy_to_user_state(x, p);
 366
 367         if (x->aalg)
 368                 RTA_PUT(skb, XFRMA_ALG_AUTH,
 369                         sizeof(*(x->aalg))+(x->aalg->alg_key_len+7)/8, x->aalg);
 370         if (x->ealg)
 371                 RTA_PUT(skb, XFRMA_ALG_CRYPT,
 372                         sizeof(*(x->ealg))+(x->ealg->alg_key_len+7)/8, x->ealg);
 373         if (x->calg)
 374                 RTA_PUT(skb, XFRMA_ALG_COMP, sizeof(*(x->calg)), x->calg);
 375
 376         if (x->encap)
 377                 RTA_PUT(skb, XFRMA_ENCAP, sizeof(*x->encap), x->encap);
 378
 379         nlh->nlmsg_len = skb->tail - b;
 380 out:
 381         sp->this_idx++;
 382         return 0;
 383
 384 nlmsg_failure:
 385 rtattr_failure:
 386         skb_trim(skb, b - skb->data);
 387         return -1;
 388 }
 389
 390 static int xfrm_dump_sa(struct sk_buff *skb, struct netlink_callback *cb)
 391 {
 392         struct xfrm_dump_info info;
 393
 394         info.in_skb = cb->skb;
 395         info.out_skb = skb;
 396         info.nlmsg_seq = cb->nlh->nlmsg_seq;
 397         info.nlmsg_flags = NLM_F_MULTI;
 398         info.this_idx = 0;
 399         info.start_idx = cb->args[0];
 400         (void) xfrm_state_walk(IPSEC_PROTO_ANY, dump_one_state, &info);
 401         cb->args[0] = info.this_idx;
 402
 403         return skb->len;
 404 }
 405
 406 static struct sk_buff *xfrm_state_netlink(struct sk_buff *in_skb,
 407                                           struct xfrm_state *x, u32 seq)
 408 {
 409         struct xfrm_dump_info info;
 410         struct sk_buff *skb;
 411
 412         skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
 413         if (!skb)
 414                 return ERR_PTR(-ENOMEM);
 415
 416         NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid;
 417         info.in_skb = in_skb;
 418         info.out_skb = skb;
 419         info.nlmsg_seq = seq;
 420         info.nlmsg_flags = 0;
 421         info.this_idx = info.start_idx = 0;
 422
 423         if (dump_one_state(x, 0, &info)) {
 424                 kfree_skb(skb);
 425                 return NULL;
 426         }
 427
 428         return skb;
 429 }
 430
 431 static int xfrm_get_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 432 {
 433         struct xfrm_usersa_id *p = NLMSG_DATA(nlh);
 434         struct xfrm_state *x;
 435         struct sk_buff *resp_skb;
 436         int err;
 437
 438         x = xfrm_state_lookup(&p->daddr, p->spi, p->proto, p->family);
 439         err = -ESRCH;
 440         if (x == NULL)
 441                 goto out_noput;
 442
 443         resp_skb = xfrm_state_netlink(skb, x, nlh->nlmsg_seq);
 444         if (IS_ERR(resp_skb)) {
 445                 err = PTR_ERR(resp_skb);
 446         } else {
 447                 err = netlink_unicast(xfrm_nl, resp_skb,
 448                                       NETLINK_CB(skb).pid, MSG_DONTWAIT);
 449         }
 450         xfrm_state_put(x);
 451 out_noput:
 452         return err;
 453 }
 454
 455 static int verify_userspi_info(struct xfrm_userspi_info *p)
 456 {
 457         switch (p->info.id.proto) {
 458         case IPPROTO_AH:
 459         case IPPROTO_ESP:
 460                 break;
 461
 462         case IPPROTO_COMP:
 463                 /* IPCOMP spi is 16-bits. */
 464                 if (p->max >= 0x10000)
 465                         return -EINVAL;
 466                 break;
 467
 468         default:
 469                 return -EINVAL;
 470         };
 471
 472         if (p->min > p->max)
 473                 return -EINVAL;
 474
 475         return 0;
 476 }
 477
 478 static int xfrm_alloc_userspi(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 479 {
 480         struct xfrm_state *x;
 481         struct xfrm_userspi_info *p;
 482         struct sk_buff *resp_skb;
 483         xfrm_address_t *daddr;
 484         int family;
 485         int err;
 486
 487         p = NLMSG_DATA(nlh);
 488         err = verify_userspi_info(p);
 489         if (err)
 490                 goto out_noput;
 491
 492         family = p->info.family;
 493         daddr = &p->info.id.daddr;
 494
 495         x = NULL;
 496         if (p->info.seq) {
 497                 x = xfrm_find_acq_byseq(p->info.seq);
 498                 if (x && xfrm_addr_cmp(&x->id.daddr, daddr, family)) {
 499                         xfrm_state_put(x);
 500                         x = NULL;
 501                 }
 502         }
 503
 504         if (!x)
 505                 x = xfrm_find_acq(p->info.mode, p->info.reqid,
 506                                   p->info.id.proto, daddr,
 507                                   &p->info.saddr, 1,
 508                                   family);
 509         err = -ENOENT;
 510         if (x == NULL)
 511                 goto out_noput;
 512
 513         resp_skb = ERR_PTR(-ENOENT);
 514
 515         spin_lock_bh(&x->lock);
 516         if (x->km.state != XFRM_STATE_DEAD) {
 517                 xfrm_alloc_spi(x, htonl(p->min), htonl(p->max));
 518                 if (x->id.spi)
 519                         resp_skb = xfrm_state_netlink(skb, x, nlh->nlmsg_seq);
 520         }
 521         spin_unlock_bh(&x->lock);
 522
 523         if (IS_ERR(resp_skb)) {
 524                 err = PTR_ERR(resp_skb);
 525                 goto out;
 526         }
 527
 528         err = netlink_unicast(xfrm_nl, resp_skb,
 529                               NETLINK_CB(skb).pid, MSG_DONTWAIT);
 530
 531 out:
 532         xfrm_state_put(x);
 533 out_noput:
 534         return err;
 535 }
 536
 537 static int verify_policy_dir(__u8 dir)
 538 {
 539         switch (dir) {
 540         case XFRM_POLICY_IN:
 541         case XFRM_POLICY_OUT:
 542         case XFRM_POLICY_FWD:
 543                 break;
 544
 545         default:
 546                 return -EINVAL;
 547         };
 548
 549         return 0;
 550 }
 551
 552 static int verify_newpolicy_info(struct xfrm_userpolicy_info *p)
 553 {
 554         switch (p->share) {
 555         case XFRM_SHARE_ANY:
 556         case XFRM_SHARE_SESSION:
 557         case XFRM_SHARE_USER:
 558         case XFRM_SHARE_UNIQUE:
 559                 break;
 560
 561         default:
 562                 return -EINVAL;
 563         };
 564
 565         switch (p->action) {
 566         case XFRM_POLICY_ALLOW:
 567         case XFRM_POLICY_BLOCK:
 568                 break;
 569
 570         default:
 571                 return -EINVAL;
 572         };
 573
 574         switch (p->sel.family) {
 575         case AF_INET:
 576                 break;
 577
 578         case AF_INET6:
 579 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 580                 break;
 581 #else
 582                 return  -EAFNOSUPPORT;
 583 #endif
 584
 585         default:
 586                 return -EINVAL;
 587         };
 588
 589         return verify_policy_dir(p->dir);
 590 }
 591
 592 static void copy_templates(struct xfrm_policy *xp, struct xfrm_user_tmpl *ut,
 593                            int nr)
 594 {
 595         int i;
 596
 597         xp->xfrm_nr = nr;
 598         for (i = 0; i < nr; i++, ut++) {
 599                 struct xfrm_tmpl *t = &xp->xfrm_vec[i];
 600
 601                 memcpy(&t->id, &ut->id, sizeof(struct xfrm_id));
 602                 memcpy(&t->saddr, &ut->saddr,
 603                        sizeof(xfrm_address_t));
 604                 t->reqid = ut->reqid;
 605                 t->mode = ut->mode;
 606                 t->share = ut->share;
 607                 t->optional = ut->optional;
 608                 t->aalgos = ut->aalgos;
 609                 t->ealgos = ut->ealgos;
 610                 t->calgos = ut->calgos;
 611         }
 612 }
 613
 614 static int copy_from_user_tmpl(struct xfrm_policy *pol, struct rtattr **xfrma)
 615 {
 616         struct rtattr *rt = xfrma[XFRMA_TMPL-1];
 617         struct xfrm_user_tmpl *utmpl;
 618         int nr;
 619
 620         if (!rt) {
 621                 pol->xfrm_nr = 0;
 622         } else {
 623                 nr = (rt->rta_len - sizeof(*rt)) / sizeof(*utmpl);
 624
 625                 if (nr > XFRM_MAX_DEPTH)
 626                         return -EINVAL;
 627
 628                 copy_templates(pol, RTA_DATA(rt), nr);
 629         }
 630         return 0;
 631 }
 632
 633 static void copy_from_user_policy(struct xfrm_policy *xp, struct xfrm_userpolicy_info *p)
 634 {
 635         xp->priority = p->priority;
 636         xp->index = p->index;
 637         memcpy(&xp->selector, &p->sel, sizeof(xp->selector));
 638         memcpy(&xp->lft, &p->lft, sizeof(xp->lft));
 639         xp->action = p->action;
 640         xp->flags = p->flags;
 641         xp->family = p->sel.family;
 642         /* XXX xp->share = p->share; */
 643 }
 644
 645 static void copy_to_user_policy(struct xfrm_policy *xp, struct xfrm_userpolicy_info *p, int dir)
 646 {
 647         memcpy(&p->sel, &xp->selector, sizeof(p->sel));
 648         memcpy(&p->lft, &xp->lft, sizeof(p->lft));
 649         memcpy(&p->curlft, &xp->curlft, sizeof(p->curlft));
 650         p->priority = xp->priority;
 651         p->index = xp->index;
 652         p->sel.family = xp->family;
 653         p->dir = dir;
 654         p->action = xp->action;
 655         p->flags = xp->flags;
 656         p->share = XFRM_SHARE_ANY; /* XXX xp->share */
 657 }
 658
 659 static struct xfrm_policy *xfrm_policy_construct(struct xfrm_userpolicy_info *p, struct rtattr **xfrma, int *errp)
 660 {
 661         struct xfrm_policy *xp = xfrm_policy_alloc(GFP_KERNEL);
 662         int err;
 663
 664         if (!xp) {
 665                 *errp = -ENOMEM;
 666                 return NULL;
 667         }
 668
 669         copy_from_user_policy(xp, p);
 670         err = copy_from_user_tmpl(xp, xfrma);
 671         if (err) {
 672                 *errp = err;
 673                 kfree(xp);
 674                 xp = NULL;
 675         }
 676
 677         return xp;
 678 }
 679
 680 static int xfrm_add_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 681 {
 682         struct xfrm_userpolicy_info *p = NLMSG_DATA(nlh);
 683         struct xfrm_policy *xp;
 684         int err;
 685         int excl;
 686
 687         err = verify_newpolicy_info(p);
 688         if (err)
 689                 return err;
 690
 691         xp = xfrm_policy_construct(p, (struct rtattr **) xfrma, &err);
 692         if (!xp)
 693                 return err;
 694
 695         excl = nlh->nlmsg_type == XFRM_MSG_NEWPOLICY;
 696         err = xfrm_policy_insert(p->dir, xp, excl);
 697         if (err) {
 698                 kfree(xp);
 699                 return err;
 700         }
 701
 702         xfrm_pol_put(xp);
 703
 704         return 0;
 705 }
 706
 707 static int copy_to_user_tmpl(struct xfrm_policy *xp, struct sk_buff *skb)
 708 {
 709         struct xfrm_user_tmpl vec[XFRM_MAX_DEPTH];
 710         int i;
 711
 712         if (xp->xfrm_nr == 0)
 713                 return 0;
 714
 715         for (i = 0; i < xp->xfrm_nr; i++) {
 716                 struct xfrm_user_tmpl *up = &vec[i];
 717                 struct xfrm_tmpl *kp = &xp->xfrm_vec[i];
 718
 719                 memcpy(&up->id, &kp->id, sizeof(up->id));
 720                 up->family = xp->family;
 721                 memcpy(&up->saddr, &kp->saddr, sizeof(up->saddr));
 722                 up->reqid = kp->reqid;
 723                 up->mode = kp->mode;
 724                 up->share = kp->share;
 725                 up->optional = kp->optional;
 726                 up->aalgos = kp->aalgos;
 727                 up->ealgos = kp->ealgos;
 728                 up->calgos = kp->calgos;
 729         }
 730         RTA_PUT(skb, XFRMA_TMPL,
 731                 (sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr),
 732                 vec);
 733
 734         return 0;
 735
 736 rtattr_failure:
 737         return -1;
 738 }
 739
 740 static int dump_one_policy(struct xfrm_policy *xp, int dir, int count, void *ptr)
 741 {
 742         struct xfrm_dump_info *sp = ptr;
 743         struct xfrm_userpolicy_info *p;
 744         struct sk_buff *in_skb = sp->in_skb;
 745         struct sk_buff *skb = sp->out_skb;
 746         struct nlmsghdr *nlh;
 747         unsigned char *b = skb->tail;
 748
 749         if (sp->this_idx < sp->start_idx)
 750                 goto out;
 751
 752         nlh = NLMSG_PUT(skb, NETLINK_CB(in_skb).pid,
 753                         sp->nlmsg_seq,
 754                         XFRM_MSG_NEWPOLICY, sizeof(*p));
 755         p = NLMSG_DATA(nlh);
 756         nlh->nlmsg_flags = sp->nlmsg_flags;
 757
 758         copy_to_user_policy(xp, p, dir);
 759         if (copy_to_user_tmpl(xp, skb) < 0)
 760                 goto nlmsg_failure;
 761
 762         nlh->nlmsg_len = skb->tail - b;
 763 out:
 764         sp->this_idx++;
 765         return 0;
 766
 767 nlmsg_failure:
 768         skb_trim(skb, b - skb->data);
 769         return -1;
 770 }
 771
 772 static int xfrm_dump_policy(struct sk_buff *skb, struct netlink_callback *cb)
 773 {
 774         struct xfrm_dump_info info;
 775
 776         info.in_skb = cb->skb;
 777         info.out_skb = skb;
 778         info.nlmsg_seq = cb->nlh->nlmsg_seq;
 779         info.nlmsg_flags = NLM_F_MULTI;
 780         info.this_idx = 0;
 781         info.start_idx = cb->args[0];
 782         (void) xfrm_policy_walk(dump_one_policy, &info);
 783         cb->args[0] = info.this_idx;
 784
 785         return skb->len;
 786 }
 787
 788 static struct sk_buff *xfrm_policy_netlink(struct sk_buff *in_skb,
 789                                           struct xfrm_policy *xp,
 790                                           int dir, u32 seq)
 791 {
 792         struct xfrm_dump_info info;
 793         struct sk_buff *skb;
 794
 795         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 796         if (!skb)
 797                 return ERR_PTR(-ENOMEM);
 798
 799         NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid;
 800         info.in_skb = in_skb;
 801         info.out_skb = skb;
 802         info.nlmsg_seq = seq;
 803         info.nlmsg_flags = 0;
 804         info.this_idx = info.start_idx = 0;
 805
 806         if (dump_one_policy(xp, dir, 0, &info) < 0) {
 807                 kfree_skb(skb);
 808                 return NULL;
 809         }
 810
 811         return skb;
 812 }
 813
 814 static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 815 {
 816         struct xfrm_policy *xp;
 817         struct xfrm_userpolicy_id *p;
 818         int err;
 819         int delete;
 820
 821         p = NLMSG_DATA(nlh);
 822         delete = nlh->nlmsg_type == XFRM_MSG_DELPOLICY;
 823
 824         err = verify_policy_dir(p->dir);
 825         if (err)
 826                 return err;
 827
 828         if (p->index)
 829                 xp = xfrm_policy_byid(p->dir, p->index, delete);
 830         else
 831                 xp = xfrm_policy_bysel(p->dir, &p->sel, delete);
 832         if (xp == NULL)
 833                 return -ENOENT;
 834
 835         if (!delete) {
 836                 struct sk_buff *resp_skb;
 837
 838                 resp_skb = xfrm_policy_netlink(skb, xp, p->dir, nlh->nlmsg_seq);
 839                 if (IS_ERR(resp_skb)) {
 840                         err = PTR_ERR(resp_skb);
 841                 } else {
 842                         err = netlink_unicast(xfrm_nl, resp_skb,
 843                                               NETLINK_CB(skb).pid,
 844                                               MSG_DONTWAIT);
 845                 }
 846         }
 847
 848         xfrm_pol_put(xp);
 849
 850         return err;
 851 }
 852
 853 static int xfrm_flush_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 854 {
 855         struct xfrm_usersa_flush *p = NLMSG_DATA(nlh);
 856
 857         xfrm_state_flush(p->proto);
 858         return 0;
 859 }
 860
 861 static int xfrm_flush_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 862 {
 863         xfrm_policy_flush();
 864         return 0;
 865 }
 866
 867 #define XMSGSIZE(type) NLMSG_LENGTH(sizeof(struct type))
 868
 869 static const int xfrm_msg_min[XFRM_NR_MSGTYPES] = {
 870         [XFRM_MSG_NEWSA       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_info),
 871         [XFRM_MSG_DELSA       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id),
 872         [XFRM_MSG_GETSA       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id),
 873         [XFRM_MSG_NEWPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_info),
 874         [XFRM_MSG_DELPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
 875         [XFRM_MSG_GETPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
 876         [XFRM_MSG_ALLOCSPI    - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userspi_info),
 877         [XFRM_MSG_ACQUIRE     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_acquire),
 878         [XFRM_MSG_EXPIRE      - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_expire),
 879         [XFRM_MSG_UPDPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_info),
 880         [XFRM_MSG_UPDSA       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_info),
 881         [XFRM_MSG_POLEXPIRE   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_polexpire),
 882         [XFRM_MSG_FLUSHSA     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_flush),
 883         [XFRM_MSG_FLUSHPOLICY - XFRM_MSG_BASE] = NLMSG_LENGTH(0),
 884 };
 885
 886 #undef XMSGSIZE
 887
 888 static struct xfrm_link {
 889         int (*doit)(struct sk_buff *, struct nlmsghdr *, void **);
 890         int (*dump)(struct sk_buff *, struct netlink_callback *);
 891 } xfrm_dispatch[XFRM_NR_MSGTYPES] = {
 892         [XFRM_MSG_NEWSA       - XFRM_MSG_BASE] = { .doit = xfrm_add_sa        },
 893         [XFRM_MSG_DELSA       - XFRM_MSG_BASE] = { .doit = xfrm_del_sa        },
 894         [XFRM_MSG_GETSA       - XFRM_MSG_BASE] = { .doit = xfrm_get_sa,
 895                                                    .dump = xfrm_dump_sa       },
 896         [XFRM_MSG_NEWPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_add_policy    },
 897         [XFRM_MSG_DELPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_get_policy    },
 898         [XFRM_MSG_GETPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_get_policy,
 899                                                    .dump = xfrm_dump_policy   },
 900         [XFRM_MSG_ALLOCSPI    - XFRM_MSG_BASE] = { .doit = xfrm_alloc_userspi },
 901         [XFRM_MSG_UPDPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_add_policy    },
 902         [XFRM_MSG_UPDSA       - XFRM_MSG_BASE] = { .doit = xfrm_add_sa        },
 903         [XFRM_MSG_FLUSHSA     - XFRM_MSG_BASE] = { .doit = xfrm_flush_sa      },
 904         [XFRM_MSG_FLUSHPOLICY - XFRM_MSG_BASE] = { .doit = xfrm_flush_policy  },
 905 };
 906
 907 static int xfrm_done(struct netlink_callback *cb)
 908 {
 909         return 0;
 910 }
 911
 912 static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
 913 {
 914         struct rtattr *xfrma[XFRMA_MAX];
 915         struct xfrm_link *link;
 916         int type, min_len;
 917
 918         if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
 919                 return 0;
 920
 921         type = nlh->nlmsg_type;
 922
 923         /* A control message: ignore them */
 924         if (type < XFRM_MSG_BASE)
 925                 return 0;
 926
 927         /* Unknown message: reply with EINVAL */
 928         if (type > XFRM_MSG_MAX)
 929                 goto err_einval;
 930
 931         type -= XFRM_MSG_BASE;
 932         link = &xfrm_dispatch[type];
 933
 934         /* All operations require privileges, even GET */
 935         if (security_netlink_recv(skb)) {
 936                 *errp = -EPERM;
 937                 return -1;
 938         }
 939
 940         if ((type == (XFRM_MSG_GETSA - XFRM_MSG_BASE) ||
 941              type == (XFRM_MSG_GETPOLICY - XFRM_MSG_BASE)) &&
 942             (nlh->nlmsg_flags & NLM_F_DUMP)) {
 943                 u32 rlen;
 944
 945                 if (link->dump == NULL)
 946                         goto err_einval;
 947
 948                 if ((*errp = netlink_dump_start(xfrm_nl, skb, nlh,
 949                                                 link->dump,
 950                                                 xfrm_done)) != 0) {
 951                         return -1;
 952                 }
 953                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
 954                 if (rlen > skb->len)
 955                         rlen = skb->len;
 956                 skb_pull(skb, rlen);
 957                 return -1;
 958         }
 959
 960         memset(xfrma, 0, sizeof(xfrma));
 961
 962         if (nlh->nlmsg_len < (min_len = xfrm_msg_min[type]))
 963                 goto err_einval;
 964
 965         if (nlh->nlmsg_len > min_len) {
 966                 int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
 967                 struct rtattr *attr = (void *) nlh + NLMSG_ALIGN(min_len);
 968
 969                 while (RTA_OK(attr, attrlen)) {
 970                         unsigned short flavor = attr->rta_type;
 971                         if (flavor) {
 972                                 if (flavor > XFRMA_MAX)
 973                                         goto err_einval;
 974                                 xfrma[flavor - 1] = attr;
 975                         }
 976                         attr = RTA_NEXT(attr, attrlen);
 977                 }
 978         }
 979
 980         if (link->doit == NULL)
 981                 goto err_einval;
 982         *errp = link->doit(skb, nlh, (void **) &xfrma);
 983
 984         return *errp;
 985
 986 err_einval:
 987         *errp = -EINVAL;
 988         return -1;
 989 }
 990
 991 static int xfrm_user_rcv_skb(struct sk_buff *skb)
 992 {
 993         int err;
 994         struct nlmsghdr *nlh;
 995
 996         while (skb->len >= NLMSG_SPACE(0)) {
 997                 u32 rlen;
 998
 999                 nlh = (struct nlmsghdr *) skb->data;
1000                 if (nlh->nlmsg_len < sizeof(*nlh) ||
1001                     skb->len < nlh->nlmsg_len)
1002                         return 0;
1003                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
1004                 if (rlen > skb->len)
1005                         rlen = skb->len;
1006                 if (xfrm_user_rcv_msg(skb, nlh, &err) < 0) {
1007                         if (err == 0)
1008                                 return -1;
1009                         netlink_ack(skb, nlh, err);
1010                 } else if (nlh->nlmsg_flags & NLM_F_ACK)
1011                         netlink_ack(skb, nlh, 0);
1012                 skb_pull(skb, rlen);
1013         }
1014
1015         return 0;
1016 }
1017
1018 static void xfrm_netlink_rcv(struct sock *sk, int len)
1019 {
1020         unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);
1021
1022         do {
1023                 struct sk_buff *skb;
1024
1025                 down(&xfrm_cfg_sem);
1026
1027                 if (qlen > skb_queue_len(&sk->sk_receive_queue))
1028                         qlen = skb_queue_len(&sk->sk_receive_queue);
1029
1030                 for (; qlen; qlen--) {
1031                         skb = skb_dequeue(&sk->sk_receive_queue);
1032                         if (xfrm_user_rcv_skb(skb)) {
1033                                 if (skb->len)
1034                                         skb_queue_head(&sk->sk_receive_queue,
1035                                                        skb);
1036                                 else {
1037                                         kfree_skb(skb);
1038                                         qlen--;
1039                                 }
1040                                 break;
1041                         }
1042                         kfree_skb(skb);
1043                 }
1044
1045                 up(&xfrm_cfg_sem);
1046
1047         } while (qlen);
1048 }
1049
1050 static int build_expire(struct sk_buff *skb, struct xfrm_state *x, int hard)
1051 {
1052         struct xfrm_user_expire *ue;
1053         struct nlmsghdr *nlh;
1054         unsigned char *b = skb->tail;
1055
1056         nlh = NLMSG_PUT(skb, 0, 0, XFRM_MSG_EXPIRE,
1057                         sizeof(*ue));
1058         ue = NLMSG_DATA(nlh);
1059         nlh->nlmsg_flags = 0;
1060
1061         copy_to_user_state(x, &ue->state);
1062         ue->hard = (hard != 0) ? 1 : 0;
1063
1064         nlh->nlmsg_len = skb->tail - b;
1065         return skb->len;
1066
1067 nlmsg_failure:
1068         skb_trim(skb, b - skb->data);
1069         return -1;
1070 }
1071
1072 static int xfrm_send_state_notify(struct xfrm_state *x, int hard)
1073 {
1074         struct sk_buff *skb;
1075
1076         skb = alloc_skb(sizeof(struct xfrm_user_expire) + 16, GFP_ATOMIC);
1077         if (skb == NULL)
1078                 return -ENOMEM;
1079
1080         if (build_expire(skb, x, hard) < 0)
1081                 BUG();
1082
1083         NETLINK_CB(skb).dst_groups = XFRMGRP_EXPIRE;
1084
1085         return netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_EXPIRE, GFP_ATOMIC);
1086 }
1087
1088 static int build_acquire(struct sk_buff *skb, struct xfrm_state *x,
1089                          struct xfrm_tmpl *xt, struct xfrm_policy *xp,
1090                          int dir)
1091 {
1092         struct xfrm_user_acquire *ua;
1093         struct nlmsghdr *nlh;
1094         unsigned char *b = skb->tail;
1095         __u32 seq = xfrm_get_acqseq();
1096
1097         nlh = NLMSG_PUT(skb, 0, 0, XFRM_MSG_ACQUIRE,
1098                         sizeof(*ua));
1099         ua = NLMSG_DATA(nlh);
1100         nlh->nlmsg_flags = 0;
1101
1102         memcpy(&ua->id, &x->id, sizeof(ua->id));
1103         memcpy(&ua->saddr, &x->props.saddr, sizeof(ua->saddr));
1104         memcpy(&ua->sel, &x->sel, sizeof(ua->sel));
1105         copy_to_user_policy(xp, &ua->policy, dir);
1106         ua->aalgos = xt->aalgos;
1107         ua->ealgos = xt->ealgos;
1108         ua->calgos = xt->calgos;
1109         ua->seq = x->km.seq = seq;
1110
1111         if (copy_to_user_tmpl(xp, skb) < 0)
1112                 goto nlmsg_failure;
1113
1114         nlh->nlmsg_len = skb->tail - b;
1115         return skb->len;
1116
1117 nlmsg_failure:
1118         skb_trim(skb, b - skb->data);
1119         return -1;
1120 }
1121
1122 static int xfrm_send_acquire(struct xfrm_state *x, struct xfrm_tmpl *xt,
1123                              struct xfrm_policy *xp, int dir)
1124 {
1125         struct sk_buff *skb;
1126         size_t len;
1127
1128         len = RTA_SPACE(sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr);
1129         len += NLMSG_SPACE(sizeof(struct xfrm_user_acquire));
1130         skb = alloc_skb(len, GFP_ATOMIC);
1131         if (skb == NULL)
1132                 return -ENOMEM;
1133
1134         if (build_acquire(skb, x, xt, xp, dir) < 0)
1135                 BUG();
1136
1137         NETLINK_CB(skb).dst_groups = XFRMGRP_ACQUIRE;
1138
1139         return netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_ACQUIRE, GFP_ATOMIC);
1140 }
1141
1142 /* User gives us xfrm_user_policy_info followed by an array of 0
1143  * or more templates.
1144  */
1145 static struct xfrm_policy *xfrm_compile_policy(u16 family, int opt,
1146                                                u8 *data, int len, int *dir)
1147 {
1148         struct xfrm_userpolicy_info *p = (struct xfrm_userpolicy_info *)data;
1149         struct xfrm_user_tmpl *ut = (struct xfrm_user_tmpl *) (p + 1);
1150         struct xfrm_policy *xp;
1151         int nr;
1152
1153         switch (family) {
1154         case AF_INET:
1155                 if (opt != IP_XFRM_POLICY) {
1156                         *dir = -EOPNOTSUPP;
1157                         return NULL;
1158                 }
1159                 break;
1160 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1161         case AF_INET6:
1162                 if (opt != IPV6_XFRM_POLICY) {
1163                         *dir = -EOPNOTSUPP;
1164                         return NULL;
1165                 }
1166                 break;
1167 #endif
1168         default:
1169                 *dir = -EINVAL;
1170                 return NULL;
1171         }
1172
1173         *dir = -EINVAL;
1174
1175         if (len < sizeof(*p) ||
1176             verify_newpolicy_info(p))
1177                 return NULL;
1178
1179         nr = ((len - sizeof(*p)) / sizeof(*ut));
1180         if (nr > XFRM_MAX_DEPTH)
1181                 return NULL;
1182
1183         xp = xfrm_policy_alloc(GFP_KERNEL);
1184         if (xp == NULL) {
1185                 *dir = -ENOBUFS;
1186                 return NULL;
1187         }
1188
1189         copy_from_user_policy(xp, p);
1190         copy_templates(xp, ut, nr);
1191
1192         *dir = p->dir;
1193
1194         return xp;
1195 }
1196
1197 static int build_polexpire(struct sk_buff *skb, struct xfrm_policy *xp,
1198                            int dir, int hard)
1199 {
1200         struct xfrm_user_polexpire *upe;
1201         struct nlmsghdr *nlh;
1202         unsigned char *b = skb->tail;
1203
1204         nlh = NLMSG_PUT(skb, 0, 0, XFRM_MSG_POLEXPIRE, sizeof(*upe));
1205         upe = NLMSG_DATA(nlh);
1206         nlh->nlmsg_flags = 0;
1207
1208         copy_to_user_policy(xp, &upe->pol, dir);
1209         if (copy_to_user_tmpl(xp, skb) < 0)
1210                 goto nlmsg_failure;
1211         upe->hard = !!hard;
1212
1213         nlh->nlmsg_len = skb->tail - b;
1214         return skb->len;
1215
1216 nlmsg_failure:
1217         skb_trim(skb, b - skb->data);
1218         return -1;
1219 }
1220
1221 static int xfrm_send_policy_notify(struct xfrm_policy *xp, int dir, int hard)
1222 {
1223         struct sk_buff *skb;
1224         size_t len;
1225
1226         len = RTA_SPACE(sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr);
1227         len += NLMSG_SPACE(sizeof(struct xfrm_user_polexpire));
1228         skb = alloc_skb(len, GFP_ATOMIC);
1229         if (skb == NULL)
1230                 return -ENOMEM;
1231
1232         if (build_polexpire(skb, xp, dir, hard) < 0)
1233                 BUG();
1234
1235         NETLINK_CB(skb).dst_groups = XFRMGRP_EXPIRE;
1236
1237         return netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_EXPIRE, GFP_ATOMIC);
1238 }
1239
1240 static struct xfrm_mgr netlink_mgr = {
1241         .id             = "netlink",
1242         .notify         = xfrm_send_state_notify,
1243         .acquire        = xfrm_send_acquire,
1244         .compile_policy = xfrm_compile_policy,
1245         .notify_policy  = xfrm_send_policy_notify,
1246 };
1247
1248 static int __init xfrm_user_init(void)
1249 {
1250         printk(KERN_INFO "Initializing IPsec netlink socket\n");
1251
1252         xfrm_nl = netlink_kernel_create(NETLINK_XFRM, xfrm_netlink_rcv);
1253         if (xfrm_nl == NULL)
1254                 return -ENOMEM;
1255
1256         xfrm_register_km(&netlink_mgr);
1257
1258         return 0;
1259 }
1260
1261 static void __exit xfrm_user_exit(void)
1262 {
1263         xfrm_unregister_km(&netlink_mgr);
1264         sock_release(xfrm_nl->sk_socket);
1265 }
1266
1267 module_init(xfrm_user_init);
1268 module_exit(xfrm_user_exit);
1269 MODULE_LICENSE("GPL");