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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * af_alg: User-space algorithm interface4 *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 29struct alg_type_list {30 const struct af_alg_type *type;31 struct list_head list;32};33 34static struct proto alg_proto = {35 .name = "ALG",36 .owner = THIS_MODULE,37 .obj_size = sizeof(struct alg_sock),38};39 40static LIST_HEAD(alg_types);41static DECLARE_RWSEM(alg_types_sem);42 43static 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 62int 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 85unlock:86 up_write(&alg_types_sem);87 88 return err;89}90EXPORT_SYMBOL_GPL(af_alg_register_type);91 92int 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}111EXPORT_SYMBOL_GPL(af_alg_unregister_type);112 113static 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 122int 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}130EXPORT_SYMBOL_GPL(af_alg_release);131 132void 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}146EXPORT_SYMBOL_GPL(af_alg_release_parent);147 148static 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 200unlock:201 release_sock(sk);202 203 alg_do_release(type, private);204 205 return err;206}207 208static 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 225out:226 sock_kzfree_s(sk, key, keylen);227 228 return err;229}230 231#ifdef CONFIG_KEYS232 233static 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 247static 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 261static 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 275static 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 286static 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#else347 348static 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#endif356 357static 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 else386 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 404unlock:405 release_sock(sk);406 407 return err;408}409 410int 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 override437 * 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 465unlock:466 release_sock(sk);467 468 return err;469}470EXPORT_SYMBOL_GPL(af_alg_accept);471 472static 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 478static 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 498static 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 505static 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;527out:528 return err;529}530 531static const struct net_proto_family alg_family = {532 .family = PF_ALG,533 .create = alg_create,534 .owner = THIS_MODULE,535};536 537static 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 544void 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}557EXPORT_SYMBOL_GPL(af_alg_free_sg);558 559static 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 SGL601 *602 * @sk: socket of connection to user space603 * Return: 0 upon success, < 0 upon error604 */605static 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 entries637 *638 * The counting starts from the beginning of the SGL to @bytes. If639 * an @offset is provided, the counting of the SG entries starts at the @offset.640 *641 * @sk: socket of connection to user space642 * @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 constraints645 */646unsigned 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}685EXPORT_SYMBOL_GPL(af_alg_count_tsgl);686 687/**688 * af_alg_pull_tsgl - Release the specified buffers from TX SGL689 *690 * If @dst is non-null, reassign the pages to @dst. The caller must release691 * the pages. If @dst_offset is given only reassign the pages to @dst starting692 * at the @dst_offset (byte). The caller must ensure that @dst is large693 * enough (e.g. by using af_alg_count_tsgl with the same offset).694 *695 * @sk: socket of connection to user space696 * @used: Number of bytes to pull from TX SGL697 * @dst: If non-NULL, buffer is reassigned to dst SGL instead of releasing. The698 * caller must release the buffers in dst.699 * @dst_offset: Reassign the TX SGL from given offset. All buffers before700 * reaching the offset is released.701 */702void 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}763EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);764 765/**766 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request767 *768 * @areq: Request holding the TX and RX SGL769 */770static 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 memory802 *803 * @sk: socket of connection to user space804 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep805 * Return: 0 when writable memory is available, < 0 upon error806 */807static 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 available835 *836 * @sk: socket of connection to user space837 */838void 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}854EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);855 856/**857 * af_alg_wait_for_data - wait for availability of TX data858 *859 * @sk: socket of connection to user space860 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep861 * @min: Set to minimum request size if partial requests are allowed.862 * Return: 0 when writable memory is available, < 0 upon error863 */864int 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}896EXPORT_SYMBOL_GPL(af_alg_wait_for_data);897 898/**899 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel900 *901 * @sk: socket of connection to user space902 */903static 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 handler924 *925 * The sendmsg system call handler obtains the user data and stores it926 * in ctx->tsgl_list. This implies allocation of the required numbers of927 * 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 space932 * @msg: message from user space933 * @size: size of message from user space934 * @ivsize: the size of the IV for the cipher operation to verify that the935 * user-space-provided IV has the right size936 * Return: the number of copied data upon success, < 0 upon error937 */938int 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 1105unlock:1106 af_alg_data_wakeup(sk);1107 release_sock(sk);1108 1109 return copied ?: err;1110}1111EXPORT_SYMBOL_GPL(af_alg_sendmsg);1112 1113/**1114 * af_alg_free_resources - release resources required for crypto request1115 * @areq: Request holding the TX and RX SGL1116 */1117void 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}1128EXPORT_SYMBOL_GPL(af_alg_free_resources);1129 1130/**1131 * af_alg_async_cb - AIO callback handler1132 * @data: async request completion data1133 * @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 the1137 * AIO operation.1138 *1139 * The number of bytes to be generated with the AIO operation must be set1140 * in areq->outlen before the AIO callback handler is invoked.1141 */1142void 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}1157EXPORT_SYMBOL_GPL(af_alg_async_cb);1158 1159/**1160 * af_alg_poll - poll system call handler1161 * @file: file pointer1162 * @sock: socket to poll1163 * @wait: poll_table1164 */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}1184EXPORT_SYMBOL_GPL(af_alg_poll);1185 1186/**1187 * af_alg_alloc_areq - allocate struct af_alg_async_req1188 *1189 * @sk: socket of connection to user space1190 * @areqlen: size of struct af_alg_async_req + crypto_*_reqsize1191 * Return: allocated data structure or ERR_PTR upon error1192 */1193struct 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}1219EXPORT_SYMBOL_GPL(af_alg_alloc_areq);1220 1221/**1222 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto1223 * operation1224 *1225 * @sk: socket of connection to user space1226 * @msg: user space message1227 * @flags: flags used to invoke recvmsg with1228 * @areq: instance of the cryptographic request that will hold the RX SGL1229 * @maxsize: maximum number of bytes to be pulled from user space1230 * @outlen: number of bytes in the RX SGL1231 * Return: 0 on success, < 0 upon error1232 */1233int 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}1291EXPORT_SYMBOL_GPL(af_alg_get_rsgl);1292 1293static 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 1304out:1305 return err;1306 1307out_unregister_proto:1308 proto_unregister(&alg_proto);1309 goto out;1310}1311 1312static void __exit af_alg_exit(void)1313{1314 sock_unregister(PF_ALG);1315 proto_unregister(&alg_proto);1316}1317 1318module_init(af_alg_init);1319module_exit(af_alg_exit);1320MODULE_DESCRIPTION("Crypto userspace interface");1321MODULE_LICENSE("GPL");1322MODULE_ALIAS_NETPROTO(AF_ALG);1323