1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * af_alg: User-space algorithm interface
5 * This file provides the user-space API for algorithms.
7 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
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>
29 struct alg_type_list {
30 const struct af_alg_type *type;
31 struct list_head list;
34 static struct proto alg_proto = {
37 .obj_size = sizeof(struct alg_sock),
40 static LIST_HEAD(alg_types);
41 static DECLARE_RWSEM(alg_types_sem);
43 static const struct af_alg_type *alg_get_type(const char *name)
45 const struct af_alg_type *type = ERR_PTR(-ENOENT);
46 struct alg_type_list *node;
48 down_read(&alg_types_sem);
49 list_for_each_entry(node, &alg_types, list) {
50 if (strcmp(node->type->name, name))
53 if (try_module_get(node->type->owner))
57 up_read(&alg_types_sem);
62 int af_alg_register_type(const struct af_alg_type *type)
64 struct alg_type_list *node;
67 down_write(&alg_types_sem);
68 list_for_each_entry(node, &alg_types, list) {
69 if (!strcmp(node->type->name, type->name))
73 node = kmalloc(sizeof(*node), GFP_KERNEL);
78 type->ops->owner = THIS_MODULE;
80 type->ops_nokey->owner = THIS_MODULE;
82 list_add(&node->list, &alg_types);
86 up_write(&alg_types_sem);
90 EXPORT_SYMBOL_GPL(af_alg_register_type);
92 int af_alg_unregister_type(const struct af_alg_type *type)
94 struct alg_type_list *node;
97 down_write(&alg_types_sem);
98 list_for_each_entry(node, &alg_types, list) {
99 if (strcmp(node->type->name, type->name))
102 list_del(&node->list);
107 up_write(&alg_types_sem);
111 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
113 static void alg_do_release(const struct af_alg_type *type, void *private)
118 type->release(private);
119 module_put(type->owner);
122 int af_alg_release(struct socket *sock)
130 EXPORT_SYMBOL_GPL(af_alg_release);
132 void af_alg_release_parent(struct sock *sk)
134 struct alg_sock *ask = alg_sk(sk);
135 unsigned int nokey = atomic_read(&ask->nokey_refcnt);
141 atomic_dec(&ask->nokey_refcnt);
143 if (atomic_dec_and_test(&ask->refcnt))
146 EXPORT_SYMBOL_GPL(af_alg_release_parent);
148 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
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;
158 if (sock->state == SS_CONNECTED)
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));
165 if (addr_len < sizeof(*sa) + 1)
168 /* If caller uses non-allowed flag, return error. */
169 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
172 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
173 sa->salg_name[addr_len - sizeof(*sa) - 1] = 0;
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);
182 return PTR_ERR(type);
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);
192 if (atomic_read(&ask->refcnt))
195 swap(ask->type, type);
196 swap(ask->private, private);
203 alg_do_release(type, private);
208 static int alg_setkey(struct sock *sk, sockptr_t ukey, unsigned int keylen)
210 struct alg_sock *ask = alg_sk(sk);
211 const struct af_alg_type *type = ask->type;
215 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
220 if (copy_from_sockptr(key, ukey, keylen))
223 err = type->setkey(ask->private, key, keylen);
226 sock_kzfree_s(sk, key, keylen);
233 static const u8 *key_data_ptr_user(const struct key *key,
234 unsigned int *datalen)
236 const struct user_key_payload *ukp;
238 ukp = user_key_payload_locked(key);
239 if (IS_ERR_OR_NULL(ukp))
240 return ERR_PTR(-EKEYREVOKED);
242 *datalen = key->datalen;
247 static const u8 *key_data_ptr_encrypted(const struct key *key,
248 unsigned int *datalen)
250 const struct encrypted_key_payload *ekp;
252 ekp = dereference_key_locked(key);
253 if (IS_ERR_OR_NULL(ekp))
254 return ERR_PTR(-EKEYREVOKED);
256 *datalen = ekp->decrypted_datalen;
258 return ekp->decrypted_data;
261 static const u8 *key_data_ptr_trusted(const struct key *key,
262 unsigned int *datalen)
264 const struct trusted_key_payload *tkp;
266 tkp = dereference_key_locked(key);
267 if (IS_ERR_OR_NULL(tkp))
268 return ERR_PTR(-EKEYREVOKED);
270 *datalen = tkp->key_len;
275 static struct key *lookup_key(key_serial_t serial)
279 key_ref = lookup_user_key(serial, 0, KEY_NEED_SEARCH);
281 return ERR_CAST(key_ref);
283 return key_ref_to_ptr(key_ref);
286 static int alg_setkey_by_key_serial(struct alg_sock *ask, sockptr_t optval,
289 const struct af_alg_type *type = ask->type;
291 unsigned int key_datalen;
297 if (optlen != sizeof(serial))
300 if (copy_from_sockptr(&serial, optval, optlen))
303 key = lookup_key(serial);
307 down_read(&key->sem);
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);
326 key_data = sock_kmalloc(&ask->sk, key_datalen, GFP_KERNEL);
332 memcpy(key_data, ret, key_datalen);
336 err = type->setkey(ask->private, key_data, key_datalen);
338 sock_kzfree_s(&ask->sk, key_data, key_datalen);
345 static inline int alg_setkey_by_key_serial(struct alg_sock *ask,
354 static int alg_setsockopt(struct socket *sock, int level, int optname,
355 sockptr_t optval, unsigned int optlen)
357 struct sock *sk = sock->sk;
358 struct alg_sock *ask = alg_sk(sk);
359 const struct af_alg_type *type;
363 if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt))
369 if (level != SOL_ALG || !type)
374 case ALG_SET_KEY_BY_KEY_SERIAL:
375 if (sock->state == SS_CONNECTED)
380 if (optname == ALG_SET_KEY_BY_KEY_SERIAL)
381 err = alg_setkey_by_key_serial(ask, optval, optlen);
383 err = alg_setkey(sk, optval, optlen);
385 case ALG_SET_AEAD_AUTHSIZE:
386 if (sock->state == SS_CONNECTED)
388 if (!type->setauthsize)
390 err = type->setauthsize(ask->private, optlen);
392 case ALG_SET_DRBG_ENTROPY:
393 if (sock->state == SS_CONNECTED)
395 if (!type->setentropy)
398 err = type->setentropy(ask->private, optval, optlen);
407 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
409 struct alg_sock *ask = alg_sk(sk);
410 const struct af_alg_type *type;
422 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
427 sock_init_data(newsock, sk2);
428 security_sock_graft(sk2, newsock);
429 security_sk_clone(sk, sk2);
432 * newsock->ops assigned here to allow type->accept call to override
433 * them when required.
435 newsock->ops = type->ops;
436 err = type->accept(ask->private, sk2);
438 nokey = err == -ENOKEY;
439 if (nokey && type->accept_nokey)
440 err = type->accept_nokey(ask->private, sk2);
445 if (atomic_inc_return_relaxed(&ask->refcnt) == 1)
448 atomic_inc(&ask->nokey_refcnt);
449 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
451 alg_sk(sk2)->parent = sk;
452 alg_sk(sk2)->type = type;
454 newsock->state = SS_CONNECTED;
457 newsock->ops = type->ops_nokey;
466 EXPORT_SYMBOL_GPL(af_alg_accept);
468 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
471 return af_alg_accept(sock->sk, newsock, kern);
474 static const struct proto_ops alg_proto_ops = {
476 .owner = THIS_MODULE,
478 .connect = sock_no_connect,
479 .socketpair = sock_no_socketpair,
480 .getname = sock_no_getname,
481 .ioctl = sock_no_ioctl,
482 .listen = sock_no_listen,
483 .shutdown = sock_no_shutdown,
484 .mmap = sock_no_mmap,
485 .sendpage = sock_no_sendpage,
486 .sendmsg = sock_no_sendmsg,
487 .recvmsg = sock_no_recvmsg,
490 .release = af_alg_release,
491 .setsockopt = alg_setsockopt,
492 .accept = alg_accept,
495 static void alg_sock_destruct(struct sock *sk)
497 struct alg_sock *ask = alg_sk(sk);
499 alg_do_release(ask->type, ask->private);
502 static int alg_create(struct net *net, struct socket *sock, int protocol,
508 if (sock->type != SOCK_SEQPACKET)
509 return -ESOCKTNOSUPPORT;
511 return -EPROTONOSUPPORT;
514 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
518 sock->ops = &alg_proto_ops;
519 sock_init_data(sock, sk);
521 sk->sk_destruct = alg_sock_destruct;
528 static const struct net_proto_family alg_family = {
530 .create = alg_create,
531 .owner = THIS_MODULE,
534 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
535 struct af_alg_sgl *sgl_new)
537 sg_unmark_end(sgl_prev->sgt.sgl + sgl_prev->sgt.nents - 1);
538 sg_chain(sgl_prev->sgt.sgl, sgl_prev->sgt.nents + 1, sgl_new->sgt.sgl);
541 void af_alg_free_sg(struct af_alg_sgl *sgl)
546 for (i = 0; i < sgl->sgt.nents; i++)
547 unpin_user_page(sg_page(&sgl->sgt.sgl[i]));
549 EXPORT_SYMBOL_GPL(af_alg_free_sg);
551 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
553 struct cmsghdr *cmsg;
555 for_each_cmsghdr(cmsg, msg) {
556 if (!CMSG_OK(msg, cmsg))
558 if (cmsg->cmsg_level != SOL_ALG)
561 switch (cmsg->cmsg_type) {
563 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
565 con->iv = (void *)CMSG_DATA(cmsg);
566 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
572 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
574 con->op = *(u32 *)CMSG_DATA(cmsg);
577 case ALG_SET_AEAD_ASSOCLEN:
578 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
580 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
592 * af_alg_alloc_tsgl - allocate the TX SGL
594 * @sk: socket of connection to user space
595 * Return: 0 upon success, < 0 upon error
597 static int af_alg_alloc_tsgl(struct sock *sk)
599 struct alg_sock *ask = alg_sk(sk);
600 struct af_alg_ctx *ctx = ask->private;
601 struct af_alg_tsgl *sgl;
602 struct scatterlist *sg = NULL;
604 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
605 if (!list_empty(&ctx->tsgl_list))
608 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
609 sgl = sock_kmalloc(sk,
610 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
615 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
619 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
621 list_add_tail(&sgl->list, &ctx->tsgl_list);
628 * af_alg_count_tsgl - Count number of TX SG entries
630 * The counting starts from the beginning of the SGL to @bytes. If
631 * an @offset is provided, the counting of the SG entries starts at the @offset.
633 * @sk: socket of connection to user space
634 * @bytes: Count the number of SG entries holding given number of bytes.
635 * @offset: Start the counting of SG entries from the given offset.
636 * Return: Number of TX SG entries found given the constraints
638 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
640 const struct alg_sock *ask = alg_sk(sk);
641 const struct af_alg_ctx *ctx = ask->private;
642 const struct af_alg_tsgl *sgl;
644 unsigned int sgl_count = 0;
649 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
650 const struct scatterlist *sg = sgl->sg;
652 for (i = 0; i < sgl->cur; i++) {
656 if (offset >= sg[i].length) {
657 offset -= sg[i].length;
658 bytes -= sg[i].length;
662 bytes_count = sg[i].length - offset;
667 /* If we have seen requested number of bytes, stop */
668 if (bytes_count >= bytes)
671 bytes -= bytes_count;
677 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
680 * af_alg_pull_tsgl - Release the specified buffers from TX SGL
682 * If @dst is non-null, reassign the pages to @dst. The caller must release
683 * the pages. If @dst_offset is given only reassign the pages to @dst starting
684 * at the @dst_offset (byte). The caller must ensure that @dst is large
685 * enough (e.g. by using af_alg_count_tsgl with the same offset).
687 * @sk: socket of connection to user space
688 * @used: Number of bytes to pull from TX SGL
689 * @dst: If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
690 * caller must release the buffers in dst.
691 * @dst_offset: Reassign the TX SGL from given offset. All buffers before
692 * reaching the offset is released.
694 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
697 struct alg_sock *ask = alg_sk(sk);
698 struct af_alg_ctx *ctx = ask->private;
699 struct af_alg_tsgl *sgl;
700 struct scatterlist *sg;
701 unsigned int i, j = 0;
703 while (!list_empty(&ctx->tsgl_list)) {
704 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
708 for (i = 0; i < sgl->cur; i++) {
709 size_t plen = min_t(size_t, used, sg[i].length);
710 struct page *page = sg_page(sg + i);
716 * Assumption: caller created af_alg_count_tsgl(len)
720 if (dst_offset >= plen) {
721 /* discard page before offset */
724 /* reassign page to dst after offset */
726 sg_set_page(dst + j, page,
728 sg[i].offset + dst_offset);
734 sg[i].length -= plen;
735 sg[i].offset += plen;
744 sg_assign_page(sg + i, NULL);
747 list_del(&sgl->list);
748 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
753 ctx->init = ctx->more;
755 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
758 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
760 * @areq: Request holding the TX and RX SGL
762 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
764 struct sock *sk = areq->sk;
765 struct alg_sock *ask = alg_sk(sk);
766 struct af_alg_ctx *ctx = ask->private;
767 struct af_alg_rsgl *rsgl, *tmp;
768 struct scatterlist *tsgl;
769 struct scatterlist *sg;
772 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
773 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
774 af_alg_free_sg(&rsgl->sgl);
775 list_del(&rsgl->list);
776 if (rsgl != &areq->first_rsgl)
777 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
782 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
785 put_page(sg_page(sg));
788 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
793 * af_alg_wait_for_wmem - wait for availability of writable memory
795 * @sk: socket of connection to user space
796 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep
797 * Return: 0 when writable memory is available, < 0 upon error
799 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
801 DEFINE_WAIT_FUNC(wait, woken_wake_function);
802 int err = -ERESTARTSYS;
805 if (flags & MSG_DONTWAIT)
808 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
810 add_wait_queue(sk_sleep(sk), &wait);
812 if (signal_pending(current))
814 timeout = MAX_SCHEDULE_TIMEOUT;
815 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
820 remove_wait_queue(sk_sleep(sk), &wait);
826 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
828 * @sk: socket of connection to user space
830 void af_alg_wmem_wakeup(struct sock *sk)
832 struct socket_wq *wq;
834 if (!af_alg_writable(sk))
838 wq = rcu_dereference(sk->sk_wq);
839 if (skwq_has_sleeper(wq))
840 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
843 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
846 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
849 * af_alg_wait_for_data - wait for availability of TX data
851 * @sk: socket of connection to user space
852 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep
853 * @min: Set to minimum request size if partial requests are allowed.
854 * Return: 0 when writable memory is available, < 0 upon error
856 int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min)
858 DEFINE_WAIT_FUNC(wait, woken_wake_function);
859 struct alg_sock *ask = alg_sk(sk);
860 struct af_alg_ctx *ctx = ask->private;
862 int err = -ERESTARTSYS;
864 if (flags & MSG_DONTWAIT)
867 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
869 add_wait_queue(sk_sleep(sk), &wait);
871 if (signal_pending(current))
873 timeout = MAX_SCHEDULE_TIMEOUT;
874 if (sk_wait_event(sk, &timeout,
875 ctx->init && (!ctx->more ||
876 (min && ctx->used >= min)),
882 remove_wait_queue(sk_sleep(sk), &wait);
884 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
888 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
891 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
893 * @sk: socket of connection to user space
895 static void af_alg_data_wakeup(struct sock *sk)
897 struct alg_sock *ask = alg_sk(sk);
898 struct af_alg_ctx *ctx = ask->private;
899 struct socket_wq *wq;
905 wq = rcu_dereference(sk->sk_wq);
906 if (skwq_has_sleeper(wq))
907 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
910 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
915 * af_alg_sendmsg - implementation of sendmsg system call handler
917 * The sendmsg system call handler obtains the user data and stores it
918 * in ctx->tsgl_list. This implies allocation of the required numbers of
919 * struct af_alg_tsgl.
921 * In addition, the ctx is filled with the information sent via CMSG.
923 * @sock: socket of connection to user space
924 * @msg: message from user space
925 * @size: size of message from user space
926 * @ivsize: the size of the IV for the cipher operation to verify that the
927 * user-space-provided IV has the right size
928 * Return: the number of copied data upon success, < 0 upon error
930 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
933 struct sock *sk = sock->sk;
934 struct alg_sock *ask = alg_sk(sk);
935 struct af_alg_ctx *ctx = ask->private;
936 struct af_alg_tsgl *sgl;
937 struct af_alg_control con = {};
943 if (msg->msg_controllen) {
944 err = af_alg_cmsg_send(msg, &con);
960 if (con.iv && con.iv->ivlen != ivsize)
965 if (ctx->init && !ctx->more) {
972 "%s sent an empty control message without MSG_MORE.\n",
980 memcpy(ctx->iv, con.iv->iv, ivsize);
982 ctx->aead_assoclen = con.aead_assoclen;
986 struct scatterlist *sg;
990 /* use the existing memory in an allocated page */
992 sgl = list_entry(ctx->tsgl_list.prev,
993 struct af_alg_tsgl, list);
994 sg = sgl->sg + sgl->cur - 1;
995 len = min_t(size_t, len,
996 PAGE_SIZE - sg->offset - sg->length);
998 err = memcpy_from_msg(page_address(sg_page(sg)) +
999 sg->offset + sg->length,
1005 ctx->merge = (sg->offset + sg->length) &
1014 if (!af_alg_writable(sk)) {
1015 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
1020 /* allocate a new page */
1021 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
1023 err = af_alg_alloc_tsgl(sk);
1027 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
1031 sg_unmark_end(sg + sgl->cur - 1);
1033 if (msg->msg_flags & MSG_SPLICE_PAGES) {
1034 struct sg_table sgtable = {
1037 .orig_nents = sgl->cur,
1040 plen = extract_iter_to_sg(&msg->msg_iter, len, &sgtable,
1047 for (; sgl->cur < sgtable.nents; sgl->cur++)
1048 get_page(sg_page(&sg[sgl->cur]));
1056 unsigned int i = sgl->cur;
1058 plen = min_t(size_t, len, PAGE_SIZE);
1060 pg = alloc_page(GFP_KERNEL);
1066 sg_assign_page(sg + i, pg);
1068 err = memcpy_from_msg(
1069 page_address(sg_page(sg + i)),
1072 __free_page(sg_page(sg + i));
1073 sg_assign_page(sg + i, NULL);
1077 sg[i].length = plen;
1083 } while (len && sgl->cur < MAX_SGL_ENTS);
1087 sg_mark_end(sg + sgl->cur - 1);
1089 ctx->merge = plen & (PAGE_SIZE - 1);
1094 ctx->more = msg->msg_flags & MSG_MORE;
1097 af_alg_data_wakeup(sk);
1100 return copied ?: err;
1102 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
1105 * af_alg_sendpage - sendpage system call handler
1106 * @sock: socket of connection to user space to write to
1107 * @page: data to send
1108 * @offset: offset into page to begin sending
1109 * @size: length of data
1110 * @flags: message send/receive flags
1112 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
1114 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
1115 int offset, size_t size, int flags)
1117 struct sock *sk = sock->sk;
1118 struct alg_sock *ask = alg_sk(sk);
1119 struct af_alg_ctx *ctx = ask->private;
1120 struct af_alg_tsgl *sgl;
1123 if (flags & MSG_SENDPAGE_NOTLAST)
1127 if (!ctx->more && ctx->used)
1133 if (!af_alg_writable(sk)) {
1134 err = af_alg_wait_for_wmem(sk, flags);
1139 err = af_alg_alloc_tsgl(sk);
1144 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1147 sg_unmark_end(sgl->sg + sgl->cur - 1);
1149 sg_mark_end(sgl->sg + sgl->cur);
1152 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1157 ctx->more = flags & MSG_MORE;
1160 af_alg_data_wakeup(sk);
1165 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1168 * af_alg_free_resources - release resources required for crypto request
1169 * @areq: Request holding the TX and RX SGL
1171 void af_alg_free_resources(struct af_alg_async_req *areq)
1173 struct sock *sk = areq->sk;
1175 af_alg_free_areq_sgls(areq);
1176 sock_kfree_s(sk, areq, areq->areqlen);
1178 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1181 * af_alg_async_cb - AIO callback handler
1182 * @data: async request completion data
1183 * @err: if non-zero, error result to be returned via ki_complete();
1184 * otherwise return the AIO output length via ki_complete().
1186 * This handler cleans up the struct af_alg_async_req upon completion of the
1189 * The number of bytes to be generated with the AIO operation must be set
1190 * in areq->outlen before the AIO callback handler is invoked.
1192 void af_alg_async_cb(void *data, int err)
1194 struct af_alg_async_req *areq = data;
1195 struct sock *sk = areq->sk;
1196 struct kiocb *iocb = areq->iocb;
1197 unsigned int resultlen;
1199 /* Buffer size written by crypto operation. */
1200 resultlen = areq->outlen;
1202 af_alg_free_resources(areq);
1205 iocb->ki_complete(iocb, err ? err : (int)resultlen);
1207 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1210 * af_alg_poll - poll system call handler
1211 * @file: file pointer
1212 * @sock: socket to poll
1215 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1218 struct sock *sk = sock->sk;
1219 struct alg_sock *ask = alg_sk(sk);
1220 struct af_alg_ctx *ctx = ask->private;
1223 sock_poll_wait(file, sock, wait);
1226 if (!ctx->more || ctx->used)
1227 mask |= EPOLLIN | EPOLLRDNORM;
1229 if (af_alg_writable(sk))
1230 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1234 EXPORT_SYMBOL_GPL(af_alg_poll);
1237 * af_alg_alloc_areq - allocate struct af_alg_async_req
1239 * @sk: socket of connection to user space
1240 * @areqlen: size of struct af_alg_async_req + crypto_*_reqsize
1241 * Return: allocated data structure or ERR_PTR upon error
1243 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1244 unsigned int areqlen)
1246 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1248 if (unlikely(!areq))
1249 return ERR_PTR(-ENOMEM);
1251 areq->areqlen = areqlen;
1253 areq->last_rsgl = NULL;
1254 INIT_LIST_HEAD(&areq->rsgl_list);
1256 areq->tsgl_entries = 0;
1260 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1263 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1266 * @sk: socket of connection to user space
1267 * @msg: user space message
1268 * @flags: flags used to invoke recvmsg with
1269 * @areq: instance of the cryptographic request that will hold the RX SGL
1270 * @maxsize: maximum number of bytes to be pulled from user space
1271 * @outlen: number of bytes in the RX SGL
1272 * Return: 0 on success, < 0 upon error
1274 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1275 struct af_alg_async_req *areq, size_t maxsize,
1278 struct alg_sock *ask = alg_sk(sk);
1279 struct af_alg_ctx *ctx = ask->private;
1282 while (maxsize > len && msg_data_left(msg)) {
1283 struct af_alg_rsgl *rsgl;
1287 /* limit the amount of readable buffers */
1288 if (!af_alg_readable(sk))
1291 seglen = min_t(size_t, (maxsize - len),
1292 msg_data_left(msg));
1294 if (list_empty(&areq->rsgl_list)) {
1295 rsgl = &areq->first_rsgl;
1297 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1298 if (unlikely(!rsgl))
1302 rsgl->sgl.sgt.sgl = rsgl->sgl.sgl;
1303 rsgl->sgl.sgt.nents = 0;
1304 rsgl->sgl.sgt.orig_nents = 0;
1305 list_add_tail(&rsgl->list, &areq->rsgl_list);
1307 sg_init_table(rsgl->sgl.sgt.sgl, ALG_MAX_PAGES);
1308 err = extract_iter_to_sg(&msg->msg_iter, seglen, &rsgl->sgl.sgt,
1311 rsgl->sg_num_bytes = 0;
1315 sg_mark_end(rsgl->sgl.sgt.sgl + rsgl->sgl.sgt.nents - 1);
1316 rsgl->sgl.need_unpin =
1317 iov_iter_extract_will_pin(&msg->msg_iter);
1319 /* chain the new scatterlist with previous one */
1320 if (areq->last_rsgl)
1321 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1323 areq->last_rsgl = rsgl;
1325 atomic_add(err, &ctx->rcvused);
1326 rsgl->sg_num_bytes = err;
1332 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1334 static int __init af_alg_init(void)
1336 int err = proto_register(&alg_proto, 0);
1341 err = sock_register(&alg_family);
1343 goto out_unregister_proto;
1348 out_unregister_proto:
1349 proto_unregister(&alg_proto);
1353 static void __exit af_alg_exit(void)
1355 sock_unregister(PF_ALG);
1356 proto_unregister(&alg_proto);
1359 module_init(af_alg_init);
1360 module_exit(af_alg_exit);
1361 MODULE_LICENSE("GPL");
1362 MODULE_ALIAS_NETPROTO(AF_ALG);