| 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 2 | /* |
| 3 | * af_alg: User-space algorithm interface |
| 4 | * |
| 5 | * This file provides the user-space API for algorithms. |
| 6 | * |
| 7 | * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au> |
| 8 | */ |
| 9 | |
| 10 | #include <linux/atomic.h> |
| 11 | #include <crypto/if_alg.h> |
| 12 | #include <linux/crypto.h> |
| 13 | #include <linux/init.h> |
| 14 | #include <linux/kernel.h> |
| 15 | #include <linux/key.h> |
| 16 | #include <linux/key-type.h> |
| 17 | #include <linux/list.h> |
| 18 | #include <linux/module.h> |
| 19 | #include <linux/net.h> |
| 20 | #include <linux/rwsem.h> |
| 21 | #include <linux/sched.h> |
| 22 | #include <linux/sched/signal.h> |
| 23 | #include <linux/security.h> |
| 24 | #include <linux/string.h> |
| 25 | #include <keys/user-type.h> |
| 26 | #include <keys/trusted-type.h> |
| 27 | #include <keys/encrypted-type.h> |
| 28 | |
| 29 | struct alg_type_list { |
| 30 | const struct af_alg_type *type; |
| 31 | struct list_head list; |
| 32 | }; |
| 33 | |
| 34 | static struct proto alg_proto = { |
| 35 | .name = "ALG", |
| 36 | .owner = THIS_MODULE, |
| 37 | .obj_size = sizeof(struct alg_sock), |
| 38 | }; |
| 39 | |
| 40 | static LIST_HEAD(alg_types); |
| 41 | static DECLARE_RWSEM(alg_types_sem); |
| 42 | |
| 43 | static const struct af_alg_type *alg_get_type(const char *name) |
| 44 | { |
| 45 | const struct af_alg_type *type = ERR_PTR(-ENOENT); |
| 46 | struct alg_type_list *node; |
| 47 | |
| 48 | down_read(&alg_types_sem); |
| 49 | list_for_each_entry(node, &alg_types, list) { |
| 50 | if (strcmp(node->type->name, name)) |
| 51 | continue; |
| 52 | |
| 53 | if (try_module_get(node->type->owner)) |
| 54 | type = node->type; |
| 55 | break; |
| 56 | } |
| 57 | up_read(&alg_types_sem); |
| 58 | |
| 59 | return type; |
| 60 | } |
| 61 | |
| 62 | int af_alg_register_type(const struct af_alg_type *type) |
| 63 | { |
| 64 | struct alg_type_list *node; |
| 65 | int err = -EEXIST; |
| 66 | |
| 67 | down_write(&alg_types_sem); |
| 68 | list_for_each_entry(node, &alg_types, list) { |
| 69 | if (!strcmp(node->type->name, type->name)) |
| 70 | goto unlock; |
| 71 | } |
| 72 | |
| 73 | node = kmalloc(sizeof(*node), GFP_KERNEL); |
| 74 | err = -ENOMEM; |
| 75 | if (!node) |
| 76 | goto unlock; |
| 77 | |
| 78 | type->ops->owner = THIS_MODULE; |
| 79 | if (type->ops_nokey) |
| 80 | type->ops_nokey->owner = THIS_MODULE; |
| 81 | node->type = type; |
| 82 | list_add(&node->list, &alg_types); |
| 83 | err = 0; |
| 84 | |
| 85 | unlock: |
| 86 | up_write(&alg_types_sem); |
| 87 | |
| 88 | return err; |
| 89 | } |
| 90 | EXPORT_SYMBOL_GPL(af_alg_register_type); |
| 91 | |
| 92 | int af_alg_unregister_type(const struct af_alg_type *type) |
| 93 | { |
| 94 | struct alg_type_list *node; |
| 95 | int err = -ENOENT; |
| 96 | |
| 97 | down_write(&alg_types_sem); |
| 98 | list_for_each_entry(node, &alg_types, list) { |
| 99 | if (strcmp(node->type->name, type->name)) |
| 100 | continue; |
| 101 | |
| 102 | list_del(&node->list); |
| 103 | kfree(node); |
| 104 | err = 0; |
| 105 | break; |
| 106 | } |
| 107 | up_write(&alg_types_sem); |
| 108 | |
| 109 | return err; |
| 110 | } |
| 111 | EXPORT_SYMBOL_GPL(af_alg_unregister_type); |
| 112 | |
| 113 | static void alg_do_release(const struct af_alg_type *type, void *private) |
| 114 | { |
| 115 | if (!type) |
| 116 | return; |
| 117 | |
| 118 | type->release(private); |
| 119 | module_put(type->owner); |
| 120 | } |
| 121 | |
| 122 | int af_alg_release(struct socket *sock) |
| 123 | { |
| 124 | if (sock->sk) { |
| 125 | sock_put(sock->sk); |
| 126 | sock->sk = NULL; |
| 127 | } |
| 128 | return 0; |
| 129 | } |
| 130 | EXPORT_SYMBOL_GPL(af_alg_release); |
| 131 | |
| 132 | void af_alg_release_parent(struct sock *sk) |
| 133 | { |
| 134 | struct alg_sock *ask = alg_sk(sk); |
| 135 | unsigned int nokey = atomic_read(&ask->nokey_refcnt); |
| 136 | |
| 137 | sk = ask->parent; |
| 138 | ask = alg_sk(sk); |
| 139 | |
| 140 | if (nokey) |
| 141 | atomic_dec(&ask->nokey_refcnt); |
| 142 | |
| 143 | if (atomic_dec_and_test(&ask->refcnt)) |
| 144 | sock_put(sk); |
| 145 | } |
| 146 | EXPORT_SYMBOL_GPL(af_alg_release_parent); |
| 147 | |
| 148 | static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) |
| 149 | { |
| 150 | const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY; |
| 151 | struct sock *sk = sock->sk; |
| 152 | struct alg_sock *ask = alg_sk(sk); |
| 153 | struct sockaddr_alg_new *sa = (void *)uaddr; |
| 154 | const struct af_alg_type *type; |
| 155 | void *private; |
| 156 | int err; |
| 157 | |
| 158 | if (sock->state == SS_CONNECTED) |
| 159 | return -EINVAL; |
| 160 | |
| 161 | BUILD_BUG_ON(offsetof(struct sockaddr_alg_new, salg_name) != |
| 162 | offsetof(struct sockaddr_alg, salg_name)); |
| 163 | BUILD_BUG_ON(offsetof(struct sockaddr_alg, salg_name) != sizeof(*sa)); |
| 164 | |
| 165 | if (addr_len < sizeof(*sa) + 1) |
| 166 | return -EINVAL; |
| 167 | |
| 168 | /* If caller uses non-allowed flag, return error. */ |
| 169 | if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed)) |
| 170 | return -EINVAL; |
| 171 | |
| 172 | sa->salg_type[sizeof(sa->salg_type) - 1] = 0; |
| 173 | sa->salg_name[addr_len - sizeof(*sa) - 1] = 0; |
| 174 | |
| 175 | type = alg_get_type(sa->salg_type); |
| 176 | if (PTR_ERR(type) == -ENOENT) { |
| 177 | request_module("algif-%s", sa->salg_type); |
| 178 | type = alg_get_type(sa->salg_type); |
| 179 | } |
| 180 | |
| 181 | if (IS_ERR(type)) |
| 182 | return PTR_ERR(type); |
| 183 | |
| 184 | private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask); |
| 185 | if (IS_ERR(private)) { |
| 186 | module_put(type->owner); |
| 187 | return PTR_ERR(private); |
| 188 | } |
| 189 | |
| 190 | err = -EBUSY; |
| 191 | lock_sock(sk); |
| 192 | if (atomic_read(&ask->refcnt)) |
| 193 | goto unlock; |
| 194 | |
| 195 | swap(ask->type, type); |
| 196 | swap(ask->private, private); |
| 197 | |
| 198 | err = 0; |
| 199 | |
| 200 | unlock: |
| 201 | release_sock(sk); |
| 202 | |
| 203 | alg_do_release(type, private); |
| 204 | |
| 205 | return err; |
| 206 | } |
| 207 | |
| 208 | static int alg_setkey(struct sock *sk, sockptr_t ukey, unsigned int keylen) |
| 209 | { |
| 210 | struct alg_sock *ask = alg_sk(sk); |
| 211 | const struct af_alg_type *type = ask->type; |
| 212 | u8 *key; |
| 213 | int err; |
| 214 | |
| 215 | key = sock_kmalloc(sk, keylen, GFP_KERNEL); |
| 216 | if (!key) |
| 217 | return -ENOMEM; |
| 218 | |
| 219 | err = -EFAULT; |
| 220 | if (copy_from_sockptr(key, ukey, keylen)) |
| 221 | goto out; |
| 222 | |
| 223 | err = type->setkey(ask->private, key, keylen); |
| 224 | |
| 225 | out: |
| 226 | sock_kzfree_s(sk, key, keylen); |
| 227 | |
| 228 | return err; |
| 229 | } |
| 230 | |
| 231 | #ifdef CONFIG_KEYS |
| 232 | |
| 233 | static const u8 *key_data_ptr_user(const struct key *key, |
| 234 | unsigned int *datalen) |
| 235 | { |
| 236 | const struct user_key_payload *ukp; |
| 237 | |
| 238 | ukp = user_key_payload_locked(key); |
| 239 | if (IS_ERR_OR_NULL(ukp)) |
| 240 | return ERR_PTR(-EKEYREVOKED); |
| 241 | |
| 242 | *datalen = key->datalen; |
| 243 | |
| 244 | return ukp->data; |
| 245 | } |
| 246 | |
| 247 | static const u8 *key_data_ptr_encrypted(const struct key *key, |
| 248 | unsigned int *datalen) |
| 249 | { |
| 250 | const struct encrypted_key_payload *ekp; |
| 251 | |
| 252 | ekp = dereference_key_locked(key); |
| 253 | if (IS_ERR_OR_NULL(ekp)) |
| 254 | return ERR_PTR(-EKEYREVOKED); |
| 255 | |
| 256 | *datalen = ekp->decrypted_datalen; |
| 257 | |
| 258 | return ekp->decrypted_data; |
| 259 | } |
| 260 | |
| 261 | static const u8 *key_data_ptr_trusted(const struct key *key, |
| 262 | unsigned int *datalen) |
| 263 | { |
| 264 | const struct trusted_key_payload *tkp; |
| 265 | |
| 266 | tkp = dereference_key_locked(key); |
| 267 | if (IS_ERR_OR_NULL(tkp)) |
| 268 | return ERR_PTR(-EKEYREVOKED); |
| 269 | |
| 270 | *datalen = tkp->key_len; |
| 271 | |
| 272 | return tkp->key; |
| 273 | } |
| 274 | |
| 275 | static struct key *lookup_key(key_serial_t serial) |
| 276 | { |
| 277 | key_ref_t key_ref; |
| 278 | |
| 279 | key_ref = lookup_user_key(serial, 0, KEY_NEED_SEARCH); |
| 280 | if (IS_ERR(key_ref)) |
| 281 | return ERR_CAST(key_ref); |
| 282 | |
| 283 | return key_ref_to_ptr(key_ref); |
| 284 | } |
| 285 | |
| 286 | static int alg_setkey_by_key_serial(struct alg_sock *ask, sockptr_t optval, |
| 287 | unsigned int optlen) |
| 288 | { |
| 289 | const struct af_alg_type *type = ask->type; |
| 290 | u8 *key_data = NULL; |
| 291 | unsigned int key_datalen; |
| 292 | key_serial_t serial; |
| 293 | struct key *key; |
| 294 | const u8 *ret; |
| 295 | int err; |
| 296 | |
| 297 | if (optlen != sizeof(serial)) |
| 298 | return -EINVAL; |
| 299 | |
| 300 | if (copy_from_sockptr(&serial, optval, optlen)) |
| 301 | return -EFAULT; |
| 302 | |
| 303 | key = lookup_key(serial); |
| 304 | if (IS_ERR(key)) |
| 305 | return PTR_ERR(key); |
| 306 | |
| 307 | down_read(&key->sem); |
| 308 | |
| 309 | ret = ERR_PTR(-ENOPROTOOPT); |
| 310 | if (!strcmp(key->type->name, "user") || |
| 311 | !strcmp(key->type->name, "logon")) { |
| 312 | ret = key_data_ptr_user(key, &key_datalen); |
| 313 | } else if (IS_REACHABLE(CONFIG_ENCRYPTED_KEYS) && |
| 314 | !strcmp(key->type->name, "encrypted")) { |
| 315 | ret = key_data_ptr_encrypted(key, &key_datalen); |
| 316 | } else if (IS_REACHABLE(CONFIG_TRUSTED_KEYS) && |
| 317 | !strcmp(key->type->name, "trusted")) { |
| 318 | ret = key_data_ptr_trusted(key, &key_datalen); |
| 319 | } |
| 320 | |
| 321 | if (IS_ERR(ret)) { |
| 322 | up_read(&key->sem); |
| 323 | key_put(key); |
| 324 | return PTR_ERR(ret); |
| 325 | } |
| 326 | |
| 327 | key_data = sock_kmalloc(&ask->sk, key_datalen, GFP_KERNEL); |
| 328 | if (!key_data) { |
| 329 | up_read(&key->sem); |
| 330 | key_put(key); |
| 331 | return -ENOMEM; |
| 332 | } |
| 333 | |
| 334 | memcpy(key_data, ret, key_datalen); |
| 335 | |
| 336 | up_read(&key->sem); |
| 337 | key_put(key); |
| 338 | |
| 339 | err = type->setkey(ask->private, key_data, key_datalen); |
| 340 | |
| 341 | sock_kzfree_s(&ask->sk, key_data, key_datalen); |
| 342 | |
| 343 | return err; |
| 344 | } |
| 345 | |
| 346 | #else |
| 347 | |
| 348 | static inline int alg_setkey_by_key_serial(struct alg_sock *ask, |
| 349 | sockptr_t optval, |
| 350 | unsigned int optlen) |
| 351 | { |
| 352 | return -ENOPROTOOPT; |
| 353 | } |
| 354 | |
| 355 | #endif |
| 356 | |
| 357 | static int alg_setsockopt(struct socket *sock, int level, int optname, |
| 358 | sockptr_t optval, unsigned int optlen) |
| 359 | { |
| 360 | struct sock *sk = sock->sk; |
| 361 | struct alg_sock *ask = alg_sk(sk); |
| 362 | const struct af_alg_type *type; |
| 363 | int err = -EBUSY; |
| 364 | |
| 365 | lock_sock(sk); |
| 366 | if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt)) |
| 367 | goto unlock; |
| 368 | |
| 369 | type = ask->type; |
| 370 | |
| 371 | err = -ENOPROTOOPT; |
| 372 | if (level != SOL_ALG || !type) |
| 373 | goto unlock; |
| 374 | |
| 375 | switch (optname) { |
| 376 | case ALG_SET_KEY: |
| 377 | case ALG_SET_KEY_BY_KEY_SERIAL: |
| 378 | if (sock->state == SS_CONNECTED) |
| 379 | goto unlock; |
| 380 | if (!type->setkey) |
| 381 | goto unlock; |
| 382 | |
| 383 | if (optname == ALG_SET_KEY_BY_KEY_SERIAL) |
| 384 | err = alg_setkey_by_key_serial(ask, optval, optlen); |
| 385 | else |
| 386 | err = alg_setkey(sk, optval, optlen); |
| 387 | break; |
| 388 | case ALG_SET_AEAD_AUTHSIZE: |
| 389 | if (sock->state == SS_CONNECTED) |
| 390 | goto unlock; |
| 391 | if (!type->setauthsize) |
| 392 | goto unlock; |
| 393 | err = type->setauthsize(ask->private, optlen); |
| 394 | break; |
| 395 | case ALG_SET_DRBG_ENTROPY: |
| 396 | if (sock->state == SS_CONNECTED) |
| 397 | goto unlock; |
| 398 | if (!type->setentropy) |
| 399 | goto unlock; |
| 400 | |
| 401 | err = type->setentropy(ask->private, optval, optlen); |
| 402 | } |
| 403 | |
| 404 | unlock: |
| 405 | release_sock(sk); |
| 406 | |
| 407 | return err; |
| 408 | } |
| 409 | |
| 410 | int af_alg_accept(struct sock *sk, struct socket *newsock, |
| 411 | struct proto_accept_arg *arg) |
| 412 | { |
| 413 | struct alg_sock *ask = alg_sk(sk); |
| 414 | const struct af_alg_type *type; |
| 415 | struct sock *sk2; |
| 416 | unsigned int nokey; |
| 417 | int err; |
| 418 | |
| 419 | lock_sock(sk); |
| 420 | type = ask->type; |
| 421 | |
| 422 | err = -EINVAL; |
| 423 | if (!type) |
| 424 | goto unlock; |
| 425 | |
| 426 | sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, arg->kern); |
| 427 | err = -ENOMEM; |
| 428 | if (!sk2) |
| 429 | goto unlock; |
| 430 | |
| 431 | sock_init_data(newsock, sk2); |
| 432 | security_sock_graft(sk2, newsock); |
| 433 | security_sk_clone(sk, sk2); |
| 434 | |
| 435 | /* |
| 436 | * newsock->ops assigned here to allow type->accept call to override |
| 437 | * them when required. |
| 438 | */ |
| 439 | newsock->ops = type->ops; |
| 440 | err = type->accept(ask->private, sk2); |
| 441 | |
| 442 | nokey = err == -ENOKEY; |
| 443 | if (nokey && type->accept_nokey) |
| 444 | err = type->accept_nokey(ask->private, sk2); |
| 445 | |
| 446 | if (err) |
| 447 | goto unlock; |
| 448 | |
| 449 | if (atomic_inc_return_relaxed(&ask->refcnt) == 1) |
| 450 | sock_hold(sk); |
| 451 | if (nokey) { |
| 452 | atomic_inc(&ask->nokey_refcnt); |
| 453 | atomic_set(&alg_sk(sk2)->nokey_refcnt, 1); |
| 454 | } |
| 455 | alg_sk(sk2)->parent = sk; |
| 456 | alg_sk(sk2)->type = type; |
| 457 | |
| 458 | newsock->state = SS_CONNECTED; |
| 459 | |
| 460 | if (nokey) |
| 461 | newsock->ops = type->ops_nokey; |
| 462 | |
| 463 | err = 0; |
| 464 | |
| 465 | unlock: |
| 466 | release_sock(sk); |
| 467 | |
| 468 | return err; |
| 469 | } |
| 470 | EXPORT_SYMBOL_GPL(af_alg_accept); |
| 471 | |
| 472 | static int alg_accept(struct socket *sock, struct socket *newsock, |
| 473 | struct proto_accept_arg *arg) |
| 474 | { |
| 475 | return af_alg_accept(sock->sk, newsock, arg); |
| 476 | } |
| 477 | |
| 478 | static const struct proto_ops alg_proto_ops = { |
| 479 | .family = PF_ALG, |
| 480 | .owner = THIS_MODULE, |
| 481 | |
| 482 | .connect = sock_no_connect, |
| 483 | .socketpair = sock_no_socketpair, |
| 484 | .getname = sock_no_getname, |
| 485 | .ioctl = sock_no_ioctl, |
| 486 | .listen = sock_no_listen, |
| 487 | .shutdown = sock_no_shutdown, |
| 488 | .mmap = sock_no_mmap, |
| 489 | .sendmsg = sock_no_sendmsg, |
| 490 | .recvmsg = sock_no_recvmsg, |
| 491 | |
| 492 | .bind = alg_bind, |
| 493 | .release = af_alg_release, |
| 494 | .setsockopt = alg_setsockopt, |
| 495 | .accept = alg_accept, |
| 496 | }; |
| 497 | |
| 498 | static void alg_sock_destruct(struct sock *sk) |
| 499 | { |
| 500 | struct alg_sock *ask = alg_sk(sk); |
| 501 | |
| 502 | alg_do_release(ask->type, ask->private); |
| 503 | } |
| 504 | |
| 505 | static int alg_create(struct net *net, struct socket *sock, int protocol, |
| 506 | int kern) |
| 507 | { |
| 508 | struct sock *sk; |
| 509 | int err; |
| 510 | |
| 511 | if (sock->type != SOCK_SEQPACKET) |
| 512 | return -ESOCKTNOSUPPORT; |
| 513 | if (protocol != 0) |
| 514 | return -EPROTONOSUPPORT; |
| 515 | |
| 516 | err = -ENOMEM; |
| 517 | sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern); |
| 518 | if (!sk) |
| 519 | goto out; |
| 520 | |
| 521 | sock->ops = &alg_proto_ops; |
| 522 | sock_init_data(sock, sk); |
| 523 | |
| 524 | sk->sk_destruct = alg_sock_destruct; |
| 525 | |
| 526 | return 0; |
| 527 | out: |
| 528 | return err; |
| 529 | } |
| 530 | |
| 531 | static const struct net_proto_family alg_family = { |
| 532 | .family = PF_ALG, |
| 533 | .create = alg_create, |
| 534 | .owner = THIS_MODULE, |
| 535 | }; |
| 536 | |
| 537 | static void af_alg_link_sg(struct af_alg_sgl *sgl_prev, |
| 538 | struct af_alg_sgl *sgl_new) |
| 539 | { |
| 540 | sg_unmark_end(sgl_prev->sgt.sgl + sgl_prev->sgt.nents - 1); |
| 541 | sg_chain(sgl_prev->sgt.sgl, sgl_prev->sgt.nents + 1, sgl_new->sgt.sgl); |
| 542 | } |
| 543 | |
| 544 | void af_alg_free_sg(struct af_alg_sgl *sgl) |
| 545 | { |
| 546 | int i; |
| 547 | |
| 548 | if (sgl->sgt.sgl) { |
| 549 | if (sgl->need_unpin) |
| 550 | for (i = 0; i < sgl->sgt.nents; i++) |
| 551 | unpin_user_page(sg_page(&sgl->sgt.sgl[i])); |
| 552 | if (sgl->sgt.sgl != sgl->sgl) |
| 553 | kvfree(sgl->sgt.sgl); |
| 554 | sgl->sgt.sgl = NULL; |
| 555 | } |
| 556 | } |
| 557 | EXPORT_SYMBOL_GPL(af_alg_free_sg); |
| 558 | |
| 559 | static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con) |
| 560 | { |
| 561 | struct cmsghdr *cmsg; |
| 562 | |
| 563 | for_each_cmsghdr(cmsg, msg) { |
| 564 | if (!CMSG_OK(msg, cmsg)) |
| 565 | return -EINVAL; |
| 566 | if (cmsg->cmsg_level != SOL_ALG) |
| 567 | continue; |
| 568 | |
| 569 | switch (cmsg->cmsg_type) { |
| 570 | case ALG_SET_IV: |
| 571 | if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv))) |
| 572 | return -EINVAL; |
| 573 | con->iv = (void *)CMSG_DATA(cmsg); |
| 574 | if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen + |
| 575 | sizeof(*con->iv))) |
| 576 | return -EINVAL; |
| 577 | break; |
| 578 | |
| 579 | case ALG_SET_OP: |
| 580 | if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) |
| 581 | return -EINVAL; |
| 582 | con->op = *(u32 *)CMSG_DATA(cmsg); |
| 583 | break; |
| 584 | |
| 585 | case ALG_SET_AEAD_ASSOCLEN: |
| 586 | if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) |
| 587 | return -EINVAL; |
| 588 | con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg); |
| 589 | break; |
| 590 | |
| 591 | default: |
| 592 | return -EINVAL; |
| 593 | } |
| 594 | } |
| 595 | |
| 596 | return 0; |
| 597 | } |
| 598 | |
| 599 | /** |
| 600 | * af_alg_alloc_tsgl - allocate the TX SGL |
| 601 | * |
| 602 | * @sk: socket of connection to user space |
| 603 | * Return: 0 upon success, < 0 upon error |
| 604 | */ |
| 605 | static int af_alg_alloc_tsgl(struct sock *sk) |
| 606 | { |
| 607 | struct alg_sock *ask = alg_sk(sk); |
| 608 | struct af_alg_ctx *ctx = ask->private; |
| 609 | struct af_alg_tsgl *sgl; |
| 610 | struct scatterlist *sg = NULL; |
| 611 | |
| 612 | sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list); |
| 613 | if (!list_empty(&ctx->tsgl_list)) |
| 614 | sg = sgl->sg; |
| 615 | |
| 616 | if (!sg || sgl->cur >= MAX_SGL_ENTS) { |
| 617 | sgl = sock_kmalloc(sk, |
| 618 | struct_size(sgl, sg, (MAX_SGL_ENTS + 1)), |
| 619 | GFP_KERNEL); |
| 620 | if (!sgl) |
| 621 | return -ENOMEM; |
| 622 | |
| 623 | sg_init_table(sgl->sg, MAX_SGL_ENTS + 1); |
| 624 | sgl->cur = 0; |
| 625 | |
| 626 | if (sg) |
| 627 | sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg); |
| 628 | |
| 629 | list_add_tail(&sgl->list, &ctx->tsgl_list); |
| 630 | } |
| 631 | |
| 632 | return 0; |
| 633 | } |
| 634 | |
| 635 | /** |
| 636 | * af_alg_count_tsgl - Count number of TX SG entries |
| 637 | * |
| 638 | * The counting starts from the beginning of the SGL to @bytes. If |
| 639 | * an @offset is provided, the counting of the SG entries starts at the @offset. |
| 640 | * |
| 641 | * @sk: socket of connection to user space |
| 642 | * @bytes: Count the number of SG entries holding given number of bytes. |
| 643 | * @offset: Start the counting of SG entries from the given offset. |
| 644 | * Return: Number of TX SG entries found given the constraints |
| 645 | */ |
| 646 | unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset) |
| 647 | { |
| 648 | const struct alg_sock *ask = alg_sk(sk); |
| 649 | const struct af_alg_ctx *ctx = ask->private; |
| 650 | const struct af_alg_tsgl *sgl; |
| 651 | unsigned int i; |
| 652 | unsigned int sgl_count = 0; |
| 653 | |
| 654 | if (!bytes) |
| 655 | return 0; |
| 656 | |
| 657 | list_for_each_entry(sgl, &ctx->tsgl_list, list) { |
| 658 | const struct scatterlist *sg = sgl->sg; |
| 659 | |
| 660 | for (i = 0; i < sgl->cur; i++) { |
| 661 | size_t bytes_count; |
| 662 | |
| 663 | /* Skip offset */ |
| 664 | if (offset >= sg[i].length) { |
| 665 | offset -= sg[i].length; |
| 666 | bytes -= sg[i].length; |
| 667 | continue; |
| 668 | } |
| 669 | |
| 670 | bytes_count = sg[i].length - offset; |
| 671 | |
| 672 | offset = 0; |
| 673 | sgl_count++; |
| 674 | |
| 675 | /* If we have seen requested number of bytes, stop */ |
| 676 | if (bytes_count >= bytes) |
| 677 | return sgl_count; |
| 678 | |
| 679 | bytes -= bytes_count; |
| 680 | } |
| 681 | } |
| 682 | |
| 683 | return sgl_count; |
| 684 | } |
| 685 | EXPORT_SYMBOL_GPL(af_alg_count_tsgl); |
| 686 | |
| 687 | /** |
| 688 | * af_alg_pull_tsgl - Release the specified buffers from TX SGL |
| 689 | * |
| 690 | * If @dst is non-null, reassign the pages to @dst. The caller must release |
| 691 | * the pages. If @dst_offset is given only reassign the pages to @dst starting |
| 692 | * at the @dst_offset (byte). The caller must ensure that @dst is large |
| 693 | * enough (e.g. by using af_alg_count_tsgl with the same offset). |
| 694 | * |
| 695 | * @sk: socket of connection to user space |
| 696 | * @used: Number of bytes to pull from TX SGL |
| 697 | * @dst: If non-NULL, buffer is reassigned to dst SGL instead of releasing. The |
| 698 | * caller must release the buffers in dst. |
| 699 | * @dst_offset: Reassign the TX SGL from given offset. All buffers before |
| 700 | * reaching the offset is released. |
| 701 | */ |
| 702 | void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst, |
| 703 | size_t dst_offset) |
| 704 | { |
| 705 | struct alg_sock *ask = alg_sk(sk); |
| 706 | struct af_alg_ctx *ctx = ask->private; |
| 707 | struct af_alg_tsgl *sgl; |
| 708 | struct scatterlist *sg; |
| 709 | unsigned int i, j = 0; |
| 710 | |
| 711 | while (!list_empty(&ctx->tsgl_list)) { |
| 712 | sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl, |
| 713 | list); |
| 714 | sg = sgl->sg; |
| 715 | |
| 716 | for (i = 0; i < sgl->cur; i++) { |
| 717 | size_t plen = min_t(size_t, used, sg[i].length); |
| 718 | struct page *page = sg_page(sg + i); |
| 719 | |
| 720 | if (!page) |
| 721 | continue; |
| 722 | |
| 723 | /* |
| 724 | * Assumption: caller created af_alg_count_tsgl(len) |
| 725 | * SG entries in dst. |
| 726 | */ |
| 727 | if (dst) { |
| 728 | if (dst_offset >= plen) { |
| 729 | /* discard page before offset */ |
| 730 | dst_offset -= plen; |
| 731 | } else { |
| 732 | /* reassign page to dst after offset */ |
| 733 | get_page(page); |
| 734 | sg_set_page(dst + j, page, |
| 735 | plen - dst_offset, |
| 736 | sg[i].offset + dst_offset); |
| 737 | dst_offset = 0; |
| 738 | j++; |
| 739 | } |
| 740 | } |
| 741 | |
| 742 | sg[i].length -= plen; |
| 743 | sg[i].offset += plen; |
| 744 | |
| 745 | used -= plen; |
| 746 | ctx->used -= plen; |
| 747 | |
| 748 | if (sg[i].length) |
| 749 | return; |
| 750 | |
| 751 | put_page(page); |
| 752 | sg_assign_page(sg + i, NULL); |
| 753 | } |
| 754 | |
| 755 | list_del(&sgl->list); |
| 756 | sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1)); |
| 757 | } |
| 758 | |
| 759 | if (!ctx->used) |
| 760 | ctx->merge = 0; |
| 761 | ctx->init = ctx->more; |
| 762 | } |
| 763 | EXPORT_SYMBOL_GPL(af_alg_pull_tsgl); |
| 764 | |
| 765 | /** |
| 766 | * af_alg_free_areq_sgls - Release TX and RX SGLs of the request |
| 767 | * |
| 768 | * @areq: Request holding the TX and RX SGL |
| 769 | */ |
| 770 | static void af_alg_free_areq_sgls(struct af_alg_async_req *areq) |
| 771 | { |
| 772 | struct sock *sk = areq->sk; |
| 773 | struct alg_sock *ask = alg_sk(sk); |
| 774 | struct af_alg_ctx *ctx = ask->private; |
| 775 | struct af_alg_rsgl *rsgl, *tmp; |
| 776 | struct scatterlist *tsgl; |
| 777 | struct scatterlist *sg; |
| 778 | unsigned int i; |
| 779 | |
| 780 | list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) { |
| 781 | atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused); |
| 782 | af_alg_free_sg(&rsgl->sgl); |
| 783 | list_del(&rsgl->list); |
| 784 | if (rsgl != &areq->first_rsgl) |
| 785 | sock_kfree_s(sk, rsgl, sizeof(*rsgl)); |
| 786 | } |
| 787 | |
| 788 | tsgl = areq->tsgl; |
| 789 | if (tsgl) { |
| 790 | for_each_sg(tsgl, sg, areq->tsgl_entries, i) { |
| 791 | if (!sg_page(sg)) |
| 792 | continue; |
| 793 | put_page(sg_page(sg)); |
| 794 | } |
| 795 | |
| 796 | sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl)); |
| 797 | } |
| 798 | } |
| 799 | |
| 800 | /** |
| 801 | * af_alg_wait_for_wmem - wait for availability of writable memory |
| 802 | * |
| 803 | * @sk: socket of connection to user space |
| 804 | * @flags: If MSG_DONTWAIT is set, then only report if function would sleep |
| 805 | * Return: 0 when writable memory is available, < 0 upon error |
| 806 | */ |
| 807 | static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags) |
| 808 | { |
| 809 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
| 810 | int err = -ERESTARTSYS; |
| 811 | long timeout; |
| 812 | |
| 813 | if (flags & MSG_DONTWAIT) |
| 814 | return -EAGAIN; |
| 815 | |
| 816 | sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); |
| 817 | |
| 818 | add_wait_queue(sk_sleep(sk), &wait); |
| 819 | for (;;) { |
| 820 | if (signal_pending(current)) |
| 821 | break; |
| 822 | timeout = MAX_SCHEDULE_TIMEOUT; |
| 823 | if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) { |
| 824 | err = 0; |
| 825 | break; |
| 826 | } |
| 827 | } |
| 828 | remove_wait_queue(sk_sleep(sk), &wait); |
| 829 | |
| 830 | return err; |
| 831 | } |
| 832 | |
| 833 | /** |
| 834 | * af_alg_wmem_wakeup - wakeup caller when writable memory is available |
| 835 | * |
| 836 | * @sk: socket of connection to user space |
| 837 | */ |
| 838 | void af_alg_wmem_wakeup(struct sock *sk) |
| 839 | { |
| 840 | struct socket_wq *wq; |
| 841 | |
| 842 | if (!af_alg_writable(sk)) |
| 843 | return; |
| 844 | |
| 845 | rcu_read_lock(); |
| 846 | wq = rcu_dereference(sk->sk_wq); |
| 847 | if (skwq_has_sleeper(wq)) |
| 848 | wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | |
| 849 | EPOLLRDNORM | |
| 850 | EPOLLRDBAND); |
| 851 | sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN); |
| 852 | rcu_read_unlock(); |
| 853 | } |
| 854 | EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup); |
| 855 | |
| 856 | /** |
| 857 | * af_alg_wait_for_data - wait for availability of TX data |
| 858 | * |
| 859 | * @sk: socket of connection to user space |
| 860 | * @flags: If MSG_DONTWAIT is set, then only report if function would sleep |
| 861 | * @min: Set to minimum request size if partial requests are allowed. |
| 862 | * Return: 0 when writable memory is available, < 0 upon error |
| 863 | */ |
| 864 | int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min) |
| 865 | { |
| 866 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
| 867 | struct alg_sock *ask = alg_sk(sk); |
| 868 | struct af_alg_ctx *ctx = ask->private; |
| 869 | long timeout; |
| 870 | int err = -ERESTARTSYS; |
| 871 | |
| 872 | if (flags & MSG_DONTWAIT) |
| 873 | return -EAGAIN; |
| 874 | |
| 875 | sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
| 876 | |
| 877 | add_wait_queue(sk_sleep(sk), &wait); |
| 878 | for (;;) { |
| 879 | if (signal_pending(current)) |
| 880 | break; |
| 881 | timeout = MAX_SCHEDULE_TIMEOUT; |
| 882 | if (sk_wait_event(sk, &timeout, |
| 883 | ctx->init && (!ctx->more || |
| 884 | (min && ctx->used >= min)), |
| 885 | &wait)) { |
| 886 | err = 0; |
| 887 | break; |
| 888 | } |
| 889 | } |
| 890 | remove_wait_queue(sk_sleep(sk), &wait); |
| 891 | |
| 892 | sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
| 893 | |
| 894 | return err; |
| 895 | } |
| 896 | EXPORT_SYMBOL_GPL(af_alg_wait_for_data); |
| 897 | |
| 898 | /** |
| 899 | * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel |
| 900 | * |
| 901 | * @sk: socket of connection to user space |
| 902 | */ |
| 903 | static void af_alg_data_wakeup(struct sock *sk) |
| 904 | { |
| 905 | struct alg_sock *ask = alg_sk(sk); |
| 906 | struct af_alg_ctx *ctx = ask->private; |
| 907 | struct socket_wq *wq; |
| 908 | |
| 909 | if (!ctx->used) |
| 910 | return; |
| 911 | |
| 912 | rcu_read_lock(); |
| 913 | wq = rcu_dereference(sk->sk_wq); |
| 914 | if (skwq_has_sleeper(wq)) |
| 915 | wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT | |
| 916 | EPOLLRDNORM | |
| 917 | EPOLLRDBAND); |
| 918 | sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT); |
| 919 | rcu_read_unlock(); |
| 920 | } |
| 921 | |
| 922 | /** |
| 923 | * af_alg_sendmsg - implementation of sendmsg system call handler |
| 924 | * |
| 925 | * The sendmsg system call handler obtains the user data and stores it |
| 926 | * in ctx->tsgl_list. This implies allocation of the required numbers of |
| 927 | * struct af_alg_tsgl. |
| 928 | * |
| 929 | * In addition, the ctx is filled with the information sent via CMSG. |
| 930 | * |
| 931 | * @sock: socket of connection to user space |
| 932 | * @msg: message from user space |
| 933 | * @size: size of message from user space |
| 934 | * @ivsize: the size of the IV for the cipher operation to verify that the |
| 935 | * user-space-provided IV has the right size |
| 936 | * Return: the number of copied data upon success, < 0 upon error |
| 937 | */ |
| 938 | int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, |
| 939 | unsigned int ivsize) |
| 940 | { |
| 941 | struct sock *sk = sock->sk; |
| 942 | struct alg_sock *ask = alg_sk(sk); |
| 943 | struct af_alg_ctx *ctx = ask->private; |
| 944 | struct af_alg_tsgl *sgl; |
| 945 | struct af_alg_control con = {}; |
| 946 | long copied = 0; |
| 947 | bool enc = false; |
| 948 | bool init = false; |
| 949 | int err = 0; |
| 950 | |
| 951 | if (msg->msg_controllen) { |
| 952 | err = af_alg_cmsg_send(msg, &con); |
| 953 | if (err) |
| 954 | return err; |
| 955 | |
| 956 | init = true; |
| 957 | switch (con.op) { |
| 958 | case ALG_OP_ENCRYPT: |
| 959 | enc = true; |
| 960 | break; |
| 961 | case ALG_OP_DECRYPT: |
| 962 | enc = false; |
| 963 | break; |
| 964 | default: |
| 965 | return -EINVAL; |
| 966 | } |
| 967 | |
| 968 | if (con.iv && con.iv->ivlen != ivsize) |
| 969 | return -EINVAL; |
| 970 | } |
| 971 | |
| 972 | lock_sock(sk); |
| 973 | if (ctx->init && !ctx->more) { |
| 974 | if (ctx->used) { |
| 975 | err = -EINVAL; |
| 976 | goto unlock; |
| 977 | } |
| 978 | |
| 979 | pr_info_once( |
| 980 | "%s sent an empty control message without MSG_MORE.\n", |
| 981 | current->comm); |
| 982 | } |
| 983 | ctx->init = true; |
| 984 | |
| 985 | if (init) { |
| 986 | ctx->enc = enc; |
| 987 | if (con.iv) |
| 988 | memcpy(ctx->iv, con.iv->iv, ivsize); |
| 989 | |
| 990 | ctx->aead_assoclen = con.aead_assoclen; |
| 991 | } |
| 992 | |
| 993 | while (size) { |
| 994 | struct scatterlist *sg; |
| 995 | size_t len = size; |
| 996 | ssize_t plen; |
| 997 | |
| 998 | /* use the existing memory in an allocated page */ |
| 999 | if (ctx->merge && !(msg->msg_flags & MSG_SPLICE_PAGES)) { |
| 1000 | sgl = list_entry(ctx->tsgl_list.prev, |
| 1001 | struct af_alg_tsgl, list); |
| 1002 | sg = sgl->sg + sgl->cur - 1; |
| 1003 | len = min_t(size_t, len, |
| 1004 | PAGE_SIZE - sg->offset - sg->length); |
| 1005 | |
| 1006 | err = memcpy_from_msg(page_address(sg_page(sg)) + |
| 1007 | sg->offset + sg->length, |
| 1008 | msg, len); |
| 1009 | if (err) |
| 1010 | goto unlock; |
| 1011 | |
| 1012 | sg->length += len; |
| 1013 | ctx->merge = (sg->offset + sg->length) & |
| 1014 | (PAGE_SIZE - 1); |
| 1015 | |
| 1016 | ctx->used += len; |
| 1017 | copied += len; |
| 1018 | size -= len; |
| 1019 | continue; |
| 1020 | } |
| 1021 | |
| 1022 | if (!af_alg_writable(sk)) { |
| 1023 | err = af_alg_wait_for_wmem(sk, msg->msg_flags); |
| 1024 | if (err) |
| 1025 | goto unlock; |
| 1026 | } |
| 1027 | |
| 1028 | /* allocate a new page */ |
| 1029 | len = min_t(unsigned long, len, af_alg_sndbuf(sk)); |
| 1030 | |
| 1031 | err = af_alg_alloc_tsgl(sk); |
| 1032 | if (err) |
| 1033 | goto unlock; |
| 1034 | |
| 1035 | sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, |
| 1036 | list); |
| 1037 | sg = sgl->sg; |
| 1038 | if (sgl->cur) |
| 1039 | sg_unmark_end(sg + sgl->cur - 1); |
| 1040 | |
| 1041 | if (msg->msg_flags & MSG_SPLICE_PAGES) { |
| 1042 | struct sg_table sgtable = { |
| 1043 | .sgl = sg, |
| 1044 | .nents = sgl->cur, |
| 1045 | .orig_nents = sgl->cur, |
| 1046 | }; |
| 1047 | |
| 1048 | plen = extract_iter_to_sg(&msg->msg_iter, len, &sgtable, |
| 1049 | MAX_SGL_ENTS - sgl->cur, 0); |
| 1050 | if (plen < 0) { |
| 1051 | err = plen; |
| 1052 | goto unlock; |
| 1053 | } |
| 1054 | |
| 1055 | for (; sgl->cur < sgtable.nents; sgl->cur++) |
| 1056 | get_page(sg_page(&sg[sgl->cur])); |
| 1057 | len -= plen; |
| 1058 | ctx->used += plen; |
| 1059 | copied += plen; |
| 1060 | size -= plen; |
| 1061 | ctx->merge = 0; |
| 1062 | } else { |
| 1063 | do { |
| 1064 | struct page *pg; |
| 1065 | unsigned int i = sgl->cur; |
| 1066 | |
| 1067 | plen = min_t(size_t, len, PAGE_SIZE); |
| 1068 | |
| 1069 | pg = alloc_page(GFP_KERNEL); |
| 1070 | if (!pg) { |
| 1071 | err = -ENOMEM; |
| 1072 | goto unlock; |
| 1073 | } |
| 1074 | |
| 1075 | sg_assign_page(sg + i, pg); |
| 1076 | |
| 1077 | err = memcpy_from_msg( |
| 1078 | page_address(sg_page(sg + i)), |
| 1079 | msg, plen); |
| 1080 | if (err) { |
| 1081 | __free_page(sg_page(sg + i)); |
| 1082 | sg_assign_page(sg + i, NULL); |
| 1083 | goto unlock; |
| 1084 | } |
| 1085 | |
| 1086 | sg[i].length = plen; |
| 1087 | len -= plen; |
| 1088 | ctx->used += plen; |
| 1089 | copied += plen; |
| 1090 | size -= plen; |
| 1091 | sgl->cur++; |
| 1092 | } while (len && sgl->cur < MAX_SGL_ENTS); |
| 1093 | |
| 1094 | ctx->merge = plen & (PAGE_SIZE - 1); |
| 1095 | } |
| 1096 | |
| 1097 | if (!size) |
| 1098 | sg_mark_end(sg + sgl->cur - 1); |
| 1099 | } |
| 1100 | |
| 1101 | err = 0; |
| 1102 | |
| 1103 | ctx->more = msg->msg_flags & MSG_MORE; |
| 1104 | |
| 1105 | unlock: |
| 1106 | af_alg_data_wakeup(sk); |
| 1107 | release_sock(sk); |
| 1108 | |
| 1109 | return copied ?: err; |
| 1110 | } |
| 1111 | EXPORT_SYMBOL_GPL(af_alg_sendmsg); |
| 1112 | |
| 1113 | /** |
| 1114 | * af_alg_free_resources - release resources required for crypto request |
| 1115 | * @areq: Request holding the TX and RX SGL |
| 1116 | */ |
| 1117 | void af_alg_free_resources(struct af_alg_async_req *areq) |
| 1118 | { |
| 1119 | struct sock *sk = areq->sk; |
| 1120 | struct af_alg_ctx *ctx; |
| 1121 | |
| 1122 | af_alg_free_areq_sgls(areq); |
| 1123 | sock_kfree_s(sk, areq, areq->areqlen); |
| 1124 | |
| 1125 | ctx = alg_sk(sk)->private; |
| 1126 | ctx->inflight = false; |
| 1127 | } |
| 1128 | EXPORT_SYMBOL_GPL(af_alg_free_resources); |
| 1129 | |
| 1130 | /** |
| 1131 | * af_alg_async_cb - AIO callback handler |
| 1132 | * @data: async request completion data |
| 1133 | * @err: if non-zero, error result to be returned via ki_complete(); |
| 1134 | * otherwise return the AIO output length via ki_complete(). |
| 1135 | * |
| 1136 | * This handler cleans up the struct af_alg_async_req upon completion of the |
| 1137 | * AIO operation. |
| 1138 | * |
| 1139 | * The number of bytes to be generated with the AIO operation must be set |
| 1140 | * in areq->outlen before the AIO callback handler is invoked. |
| 1141 | */ |
| 1142 | void af_alg_async_cb(void *data, int err) |
| 1143 | { |
| 1144 | struct af_alg_async_req *areq = data; |
| 1145 | struct sock *sk = areq->sk; |
| 1146 | struct kiocb *iocb = areq->iocb; |
| 1147 | unsigned int resultlen; |
| 1148 | |
| 1149 | /* Buffer size written by crypto operation. */ |
| 1150 | resultlen = areq->outlen; |
| 1151 | |
| 1152 | af_alg_free_resources(areq); |
| 1153 | sock_put(sk); |
| 1154 | |
| 1155 | iocb->ki_complete(iocb, err ? err : (int)resultlen); |
| 1156 | } |
| 1157 | EXPORT_SYMBOL_GPL(af_alg_async_cb); |
| 1158 | |
| 1159 | /** |
| 1160 | * af_alg_poll - poll system call handler |
| 1161 | * @file: file pointer |
| 1162 | * @sock: socket to poll |
| 1163 | * @wait: poll_table |
| 1164 | */ |
| 1165 | __poll_t af_alg_poll(struct file *file, struct socket *sock, |
| 1166 | poll_table *wait) |
| 1167 | { |
| 1168 | struct sock *sk = sock->sk; |
| 1169 | struct alg_sock *ask = alg_sk(sk); |
| 1170 | struct af_alg_ctx *ctx = ask->private; |
| 1171 | __poll_t mask; |
| 1172 | |
| 1173 | sock_poll_wait(file, sock, wait); |
| 1174 | mask = 0; |
| 1175 | |
| 1176 | if (!ctx->more || ctx->used) |
| 1177 | mask |= EPOLLIN | EPOLLRDNORM; |
| 1178 | |
| 1179 | if (af_alg_writable(sk)) |
| 1180 | mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND; |
| 1181 | |
| 1182 | return mask; |
| 1183 | } |
| 1184 | EXPORT_SYMBOL_GPL(af_alg_poll); |
| 1185 | |
| 1186 | /** |
| 1187 | * af_alg_alloc_areq - allocate struct af_alg_async_req |
| 1188 | * |
| 1189 | * @sk: socket of connection to user space |
| 1190 | * @areqlen: size of struct af_alg_async_req + crypto_*_reqsize |
| 1191 | * Return: allocated data structure or ERR_PTR upon error |
| 1192 | */ |
| 1193 | struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk, |
| 1194 | unsigned int areqlen) |
| 1195 | { |
| 1196 | struct af_alg_ctx *ctx = alg_sk(sk)->private; |
| 1197 | struct af_alg_async_req *areq; |
| 1198 | |
| 1199 | /* Only one AIO request can be in flight. */ |
| 1200 | if (ctx->inflight) |
| 1201 | return ERR_PTR(-EBUSY); |
| 1202 | |
| 1203 | areq = sock_kmalloc(sk, areqlen, GFP_KERNEL); |
| 1204 | if (unlikely(!areq)) |
| 1205 | return ERR_PTR(-ENOMEM); |
| 1206 | |
| 1207 | ctx->inflight = true; |
| 1208 | |
| 1209 | areq->areqlen = areqlen; |
| 1210 | areq->sk = sk; |
| 1211 | areq->first_rsgl.sgl.sgt.sgl = areq->first_rsgl.sgl.sgl; |
| 1212 | areq->last_rsgl = NULL; |
| 1213 | INIT_LIST_HEAD(&areq->rsgl_list); |
| 1214 | areq->tsgl = NULL; |
| 1215 | areq->tsgl_entries = 0; |
| 1216 | |
| 1217 | return areq; |
| 1218 | } |
| 1219 | EXPORT_SYMBOL_GPL(af_alg_alloc_areq); |
| 1220 | |
| 1221 | /** |
| 1222 | * af_alg_get_rsgl - create the RX SGL for the output data from the crypto |
| 1223 | * operation |
| 1224 | * |
| 1225 | * @sk: socket of connection to user space |
| 1226 | * @msg: user space message |
| 1227 | * @flags: flags used to invoke recvmsg with |
| 1228 | * @areq: instance of the cryptographic request that will hold the RX SGL |
| 1229 | * @maxsize: maximum number of bytes to be pulled from user space |
| 1230 | * @outlen: number of bytes in the RX SGL |
| 1231 | * Return: 0 on success, < 0 upon error |
| 1232 | */ |
| 1233 | int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags, |
| 1234 | struct af_alg_async_req *areq, size_t maxsize, |
| 1235 | size_t *outlen) |
| 1236 | { |
| 1237 | struct alg_sock *ask = alg_sk(sk); |
| 1238 | struct af_alg_ctx *ctx = ask->private; |
| 1239 | size_t len = 0; |
| 1240 | |
| 1241 | while (maxsize > len && msg_data_left(msg)) { |
| 1242 | struct af_alg_rsgl *rsgl; |
| 1243 | ssize_t err; |
| 1244 | size_t seglen; |
| 1245 | |
| 1246 | /* limit the amount of readable buffers */ |
| 1247 | if (!af_alg_readable(sk)) |
| 1248 | break; |
| 1249 | |
| 1250 | seglen = min_t(size_t, (maxsize - len), |
| 1251 | msg_data_left(msg)); |
| 1252 | |
| 1253 | if (list_empty(&areq->rsgl_list)) { |
| 1254 | rsgl = &areq->first_rsgl; |
| 1255 | } else { |
| 1256 | rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL); |
| 1257 | if (unlikely(!rsgl)) |
| 1258 | return -ENOMEM; |
| 1259 | } |
| 1260 | |
| 1261 | rsgl->sgl.need_unpin = |
| 1262 | iov_iter_extract_will_pin(&msg->msg_iter); |
| 1263 | rsgl->sgl.sgt.sgl = rsgl->sgl.sgl; |
| 1264 | rsgl->sgl.sgt.nents = 0; |
| 1265 | rsgl->sgl.sgt.orig_nents = 0; |
| 1266 | list_add_tail(&rsgl->list, &areq->rsgl_list); |
| 1267 | |
| 1268 | sg_init_table(rsgl->sgl.sgt.sgl, ALG_MAX_PAGES); |
| 1269 | err = extract_iter_to_sg(&msg->msg_iter, seglen, &rsgl->sgl.sgt, |
| 1270 | ALG_MAX_PAGES, 0); |
| 1271 | if (err < 0) { |
| 1272 | rsgl->sg_num_bytes = 0; |
| 1273 | return err; |
| 1274 | } |
| 1275 | |
| 1276 | sg_mark_end(rsgl->sgl.sgt.sgl + rsgl->sgl.sgt.nents - 1); |
| 1277 | |
| 1278 | /* chain the new scatterlist with previous one */ |
| 1279 | if (areq->last_rsgl) |
| 1280 | af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl); |
| 1281 | |
| 1282 | areq->last_rsgl = rsgl; |
| 1283 | len += err; |
| 1284 | atomic_add(err, &ctx->rcvused); |
| 1285 | rsgl->sg_num_bytes = err; |
| 1286 | } |
| 1287 | |
| 1288 | *outlen = len; |
| 1289 | return 0; |
| 1290 | } |
| 1291 | EXPORT_SYMBOL_GPL(af_alg_get_rsgl); |
| 1292 | |
| 1293 | static int __init af_alg_init(void) |
| 1294 | { |
| 1295 | int err = proto_register(&alg_proto, 0); |
| 1296 | |
| 1297 | if (err) |
| 1298 | goto out; |
| 1299 | |
| 1300 | err = sock_register(&alg_family); |
| 1301 | if (err != 0) |
| 1302 | goto out_unregister_proto; |
| 1303 | |
| 1304 | out: |
| 1305 | return err; |
| 1306 | |
| 1307 | out_unregister_proto: |
| 1308 | proto_unregister(&alg_proto); |
| 1309 | goto out; |
| 1310 | } |
| 1311 | |
| 1312 | static void __exit af_alg_exit(void) |
| 1313 | { |
| 1314 | sock_unregister(PF_ALG); |
| 1315 | proto_unregister(&alg_proto); |
| 1316 | } |
| 1317 | |
| 1318 | module_init(af_alg_init); |
| 1319 | module_exit(af_alg_exit); |
| 1320 | MODULE_DESCRIPTION("Crypto userspace interface"); |
| 1321 | MODULE_LICENSE("GPL"); |
| 1322 | MODULE_ALIAS_NETPROTO(AF_ALG); |