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/list.h>
16 #include <linux/module.h>
17 #include <linux/net.h>
18 #include <linux/rwsem.h>
19 #include <linux/sched.h>
20 #include <linux/sched/signal.h>
21 #include <linux/security.h>
23 struct alg_type_list {
24 const struct af_alg_type *type;
25 struct list_head list;
28 static atomic_long_t alg_memory_allocated;
30 static struct proto alg_proto = {
33 .memory_allocated = &alg_memory_allocated,
34 .obj_size = sizeof(struct alg_sock),
37 static LIST_HEAD(alg_types);
38 static DECLARE_RWSEM(alg_types_sem);
40 static const struct af_alg_type *alg_get_type(const char *name)
42 const struct af_alg_type *type = ERR_PTR(-ENOENT);
43 struct alg_type_list *node;
45 down_read(&alg_types_sem);
46 list_for_each_entry(node, &alg_types, list) {
47 if (strcmp(node->type->name, name))
50 if (try_module_get(node->type->owner))
54 up_read(&alg_types_sem);
59 int af_alg_register_type(const struct af_alg_type *type)
61 struct alg_type_list *node;
64 down_write(&alg_types_sem);
65 list_for_each_entry(node, &alg_types, list) {
66 if (!strcmp(node->type->name, type->name))
70 node = kmalloc(sizeof(*node), GFP_KERNEL);
75 type->ops->owner = THIS_MODULE;
77 type->ops_nokey->owner = THIS_MODULE;
79 list_add(&node->list, &alg_types);
83 up_write(&alg_types_sem);
87 EXPORT_SYMBOL_GPL(af_alg_register_type);
89 int af_alg_unregister_type(const struct af_alg_type *type)
91 struct alg_type_list *node;
94 down_write(&alg_types_sem);
95 list_for_each_entry(node, &alg_types, list) {
96 if (strcmp(node->type->name, type->name))
99 list_del(&node->list);
104 up_write(&alg_types_sem);
108 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
110 static void alg_do_release(const struct af_alg_type *type, void *private)
115 type->release(private);
116 module_put(type->owner);
119 int af_alg_release(struct socket *sock)
127 EXPORT_SYMBOL_GPL(af_alg_release);
129 void af_alg_release_parent(struct sock *sk)
131 struct alg_sock *ask = alg_sk(sk);
132 unsigned int nokey = atomic_read(&ask->nokey_refcnt);
138 atomic_dec(&ask->nokey_refcnt);
140 if (atomic_dec_and_test(&ask->refcnt))
143 EXPORT_SYMBOL_GPL(af_alg_release_parent);
145 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
147 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
148 struct sock *sk = sock->sk;
149 struct alg_sock *ask = alg_sk(sk);
150 struct sockaddr_alg_new *sa = (void *)uaddr;
151 const struct af_alg_type *type;
155 if (sock->state == SS_CONNECTED)
158 BUILD_BUG_ON(offsetof(struct sockaddr_alg_new, salg_name) !=
159 offsetof(struct sockaddr_alg, salg_name));
160 BUILD_BUG_ON(offsetof(struct sockaddr_alg, salg_name) != sizeof(*sa));
162 if (addr_len < sizeof(*sa) + 1)
165 /* If caller uses non-allowed flag, return error. */
166 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
169 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
170 sa->salg_name[addr_len - sizeof(*sa) - 1] = 0;
172 type = alg_get_type(sa->salg_type);
173 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
174 request_module("algif-%s", sa->salg_type);
175 type = alg_get_type(sa->salg_type);
179 return PTR_ERR(type);
181 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
182 if (IS_ERR(private)) {
183 module_put(type->owner);
184 return PTR_ERR(private);
189 if (atomic_read(&ask->refcnt))
192 swap(ask->type, type);
193 swap(ask->private, private);
200 alg_do_release(type, private);
205 static int alg_setkey(struct sock *sk, char __user *ukey,
208 struct alg_sock *ask = alg_sk(sk);
209 const struct af_alg_type *type = ask->type;
213 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
218 if (copy_from_user(key, ukey, keylen))
221 err = type->setkey(ask->private, key, keylen);
224 sock_kzfree_s(sk, key, keylen);
229 static int alg_setsockopt(struct socket *sock, int level, int optname,
230 char __user *optval, unsigned int optlen)
232 struct sock *sk = sock->sk;
233 struct alg_sock *ask = alg_sk(sk);
234 const struct af_alg_type *type;
238 if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt))
244 if (level != SOL_ALG || !type)
249 if (sock->state == SS_CONNECTED)
254 err = alg_setkey(sk, optval, optlen);
256 case ALG_SET_AEAD_AUTHSIZE:
257 if (sock->state == SS_CONNECTED)
259 if (!type->setauthsize)
261 err = type->setauthsize(ask->private, optlen);
270 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
272 struct alg_sock *ask = alg_sk(sk);
273 const struct af_alg_type *type;
285 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
290 sock_init_data(newsock, sk2);
291 security_sock_graft(sk2, newsock);
292 security_sk_clone(sk, sk2);
294 err = type->accept(ask->private, sk2);
296 nokey = err == -ENOKEY;
297 if (nokey && type->accept_nokey)
298 err = type->accept_nokey(ask->private, sk2);
303 if (atomic_inc_return_relaxed(&ask->refcnt) == 1)
306 atomic_inc(&ask->nokey_refcnt);
307 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
309 alg_sk(sk2)->parent = sk;
310 alg_sk(sk2)->type = type;
312 newsock->ops = type->ops;
313 newsock->state = SS_CONNECTED;
316 newsock->ops = type->ops_nokey;
325 EXPORT_SYMBOL_GPL(af_alg_accept);
327 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
330 return af_alg_accept(sock->sk, newsock, kern);
333 static const struct proto_ops alg_proto_ops = {
335 .owner = THIS_MODULE,
337 .connect = sock_no_connect,
338 .socketpair = sock_no_socketpair,
339 .getname = sock_no_getname,
340 .ioctl = sock_no_ioctl,
341 .listen = sock_no_listen,
342 .shutdown = sock_no_shutdown,
343 .getsockopt = sock_no_getsockopt,
344 .mmap = sock_no_mmap,
345 .sendpage = sock_no_sendpage,
346 .sendmsg = sock_no_sendmsg,
347 .recvmsg = sock_no_recvmsg,
350 .release = af_alg_release,
351 .setsockopt = alg_setsockopt,
352 .accept = alg_accept,
355 static void alg_sock_destruct(struct sock *sk)
357 struct alg_sock *ask = alg_sk(sk);
359 alg_do_release(ask->type, ask->private);
362 static int alg_create(struct net *net, struct socket *sock, int protocol,
368 if (sock->type != SOCK_SEQPACKET)
369 return -ESOCKTNOSUPPORT;
371 return -EPROTONOSUPPORT;
374 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
378 sock->ops = &alg_proto_ops;
379 sock_init_data(sock, sk);
381 sk->sk_destruct = alg_sock_destruct;
388 static const struct net_proto_family alg_family = {
390 .create = alg_create,
391 .owner = THIS_MODULE,
394 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
400 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
404 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
405 if (WARN_ON(npages == 0))
407 /* Add one extra for linking */
408 sg_init_table(sgl->sg, npages + 1);
410 for (i = 0, len = n; i < npages; i++) {
411 int plen = min_t(int, len, PAGE_SIZE - off);
413 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
418 sg_mark_end(sgl->sg + npages - 1);
419 sgl->npages = npages;
423 EXPORT_SYMBOL_GPL(af_alg_make_sg);
425 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
426 struct af_alg_sgl *sgl_new)
428 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
429 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
432 void af_alg_free_sg(struct af_alg_sgl *sgl)
436 for (i = 0; i < sgl->npages; i++)
437 put_page(sgl->pages[i]);
439 EXPORT_SYMBOL_GPL(af_alg_free_sg);
441 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
443 struct cmsghdr *cmsg;
445 for_each_cmsghdr(cmsg, msg) {
446 if (!CMSG_OK(msg, cmsg))
448 if (cmsg->cmsg_level != SOL_ALG)
451 switch (cmsg->cmsg_type) {
453 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
455 con->iv = (void *)CMSG_DATA(cmsg);
456 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
462 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
464 con->op = *(u32 *)CMSG_DATA(cmsg);
467 case ALG_SET_AEAD_ASSOCLEN:
468 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
470 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
482 * af_alg_alloc_tsgl - allocate the TX SGL
484 * @sk socket of connection to user space
485 * @return: 0 upon success, < 0 upon error
487 static int af_alg_alloc_tsgl(struct sock *sk)
489 struct alg_sock *ask = alg_sk(sk);
490 struct af_alg_ctx *ctx = ask->private;
491 struct af_alg_tsgl *sgl;
492 struct scatterlist *sg = NULL;
494 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
495 if (!list_empty(&ctx->tsgl_list))
498 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
499 sgl = sock_kmalloc(sk,
500 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
505 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
509 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
511 list_add_tail(&sgl->list, &ctx->tsgl_list);
518 * aead_count_tsgl - Count number of TX SG entries
520 * The counting starts from the beginning of the SGL to @bytes. If
521 * an offset is provided, the counting of the SG entries starts at the offset.
523 * @sk socket of connection to user space
524 * @bytes Count the number of SG entries holding given number of bytes.
525 * @offset Start the counting of SG entries from the given offset.
526 * @return Number of TX SG entries found given the constraints
528 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
530 const struct alg_sock *ask = alg_sk(sk);
531 const struct af_alg_ctx *ctx = ask->private;
532 const struct af_alg_tsgl *sgl;
534 unsigned int sgl_count = 0;
539 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
540 const struct scatterlist *sg = sgl->sg;
542 for (i = 0; i < sgl->cur; i++) {
546 if (offset >= sg[i].length) {
547 offset -= sg[i].length;
548 bytes -= sg[i].length;
552 bytes_count = sg[i].length - offset;
557 /* If we have seen requested number of bytes, stop */
558 if (bytes_count >= bytes)
561 bytes -= bytes_count;
567 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
570 * aead_pull_tsgl - Release the specified buffers from TX SGL
572 * If @dst is non-null, reassign the pages to dst. The caller must release
573 * the pages. If @dst_offset is given only reassign the pages to @dst starting
574 * at the @dst_offset (byte). The caller must ensure that @dst is large
575 * enough (e.g. by using af_alg_count_tsgl with the same offset).
577 * @sk socket of connection to user space
578 * @used Number of bytes to pull from TX SGL
579 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
580 * caller must release the buffers in dst.
581 * @dst_offset Reassign the TX SGL from given offset. All buffers before
582 * reaching the offset is released.
584 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
587 struct alg_sock *ask = alg_sk(sk);
588 struct af_alg_ctx *ctx = ask->private;
589 struct af_alg_tsgl *sgl;
590 struct scatterlist *sg;
591 unsigned int i, j = 0;
593 while (!list_empty(&ctx->tsgl_list)) {
594 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
598 for (i = 0; i < sgl->cur; i++) {
599 size_t plen = min_t(size_t, used, sg[i].length);
600 struct page *page = sg_page(sg + i);
606 * Assumption: caller created af_alg_count_tsgl(len)
610 if (dst_offset >= plen) {
611 /* discard page before offset */
614 /* reassign page to dst after offset */
616 sg_set_page(dst + j, page,
618 sg[i].offset + dst_offset);
624 sg[i].length -= plen;
625 sg[i].offset += plen;
634 sg_assign_page(sg + i, NULL);
637 list_del(&sgl->list);
638 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
643 ctx->init = ctx->more;
645 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
648 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
650 * @areq Request holding the TX and RX SGL
652 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
654 struct sock *sk = areq->sk;
655 struct alg_sock *ask = alg_sk(sk);
656 struct af_alg_ctx *ctx = ask->private;
657 struct af_alg_rsgl *rsgl, *tmp;
658 struct scatterlist *tsgl;
659 struct scatterlist *sg;
662 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
663 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
664 af_alg_free_sg(&rsgl->sgl);
665 list_del(&rsgl->list);
666 if (rsgl != &areq->first_rsgl)
667 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
672 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
675 put_page(sg_page(sg));
678 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
683 * af_alg_wait_for_wmem - wait for availability of writable memory
685 * @sk socket of connection to user space
686 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
687 * @return 0 when writable memory is available, < 0 upon error
689 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
691 DEFINE_WAIT_FUNC(wait, woken_wake_function);
692 int err = -ERESTARTSYS;
695 if (flags & MSG_DONTWAIT)
698 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
700 add_wait_queue(sk_sleep(sk), &wait);
702 if (signal_pending(current))
704 timeout = MAX_SCHEDULE_TIMEOUT;
705 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
710 remove_wait_queue(sk_sleep(sk), &wait);
716 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
718 * @sk socket of connection to user space
720 void af_alg_wmem_wakeup(struct sock *sk)
722 struct socket_wq *wq;
724 if (!af_alg_writable(sk))
728 wq = rcu_dereference(sk->sk_wq);
729 if (skwq_has_sleeper(wq))
730 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
733 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
736 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
739 * af_alg_wait_for_data - wait for availability of TX data
741 * @sk socket of connection to user space
742 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
743 * @min Set to minimum request size if partial requests are allowed.
744 * @return 0 when writable memory is available, < 0 upon error
746 int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min)
748 DEFINE_WAIT_FUNC(wait, woken_wake_function);
749 struct alg_sock *ask = alg_sk(sk);
750 struct af_alg_ctx *ctx = ask->private;
752 int err = -ERESTARTSYS;
754 if (flags & MSG_DONTWAIT)
757 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
759 add_wait_queue(sk_sleep(sk), &wait);
761 if (signal_pending(current))
763 timeout = MAX_SCHEDULE_TIMEOUT;
764 if (sk_wait_event(sk, &timeout,
765 ctx->init && (!ctx->more ||
766 (min && ctx->used >= min)),
772 remove_wait_queue(sk_sleep(sk), &wait);
774 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
778 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
781 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
783 * @sk socket of connection to user space
785 static void af_alg_data_wakeup(struct sock *sk)
787 struct alg_sock *ask = alg_sk(sk);
788 struct af_alg_ctx *ctx = ask->private;
789 struct socket_wq *wq;
795 wq = rcu_dereference(sk->sk_wq);
796 if (skwq_has_sleeper(wq))
797 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
800 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
805 * af_alg_sendmsg - implementation of sendmsg system call handler
807 * The sendmsg system call handler obtains the user data and stores it
808 * in ctx->tsgl_list. This implies allocation of the required numbers of
809 * struct af_alg_tsgl.
811 * In addition, the ctx is filled with the information sent via CMSG.
813 * @sock socket of connection to user space
814 * @msg message from user space
815 * @size size of message from user space
816 * @ivsize the size of the IV for the cipher operation to verify that the
817 * user-space-provided IV has the right size
818 * @return the number of copied data upon success, < 0 upon error
820 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
823 struct sock *sk = sock->sk;
824 struct alg_sock *ask = alg_sk(sk);
825 struct af_alg_ctx *ctx = ask->private;
826 struct af_alg_tsgl *sgl;
827 struct af_alg_control con = {};
833 if (msg->msg_controllen) {
834 err = af_alg_cmsg_send(msg, &con);
850 if (con.iv && con.iv->ivlen != ivsize)
855 if (ctx->init && !ctx->more) {
862 "%s sent an empty control message without MSG_MORE.\n",
870 memcpy(ctx->iv, con.iv->iv, ivsize);
872 ctx->aead_assoclen = con.aead_assoclen;
876 struct scatterlist *sg;
880 /* use the existing memory in an allocated page */
882 sgl = list_entry(ctx->tsgl_list.prev,
883 struct af_alg_tsgl, list);
884 sg = sgl->sg + sgl->cur - 1;
885 len = min_t(size_t, len,
886 PAGE_SIZE - sg->offset - sg->length);
888 err = memcpy_from_msg(page_address(sg_page(sg)) +
889 sg->offset + sg->length,
895 ctx->merge = (sg->offset + sg->length) &
904 if (!af_alg_writable(sk)) {
905 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
910 /* allocate a new page */
911 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
913 err = af_alg_alloc_tsgl(sk);
917 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
921 sg_unmark_end(sg + sgl->cur - 1);
924 unsigned int i = sgl->cur;
926 plen = min_t(size_t, len, PAGE_SIZE);
928 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
929 if (!sg_page(sg + i)) {
934 err = memcpy_from_msg(page_address(sg_page(sg + i)),
937 __free_page(sg_page(sg + i));
938 sg_assign_page(sg + i, NULL);
948 } while (len && sgl->cur < MAX_SGL_ENTS);
951 sg_mark_end(sg + sgl->cur - 1);
953 ctx->merge = plen & (PAGE_SIZE - 1);
958 ctx->more = msg->msg_flags & MSG_MORE;
961 af_alg_data_wakeup(sk);
964 return copied ?: err;
966 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
969 * af_alg_sendpage - sendpage system call handler
971 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
973 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
974 int offset, size_t size, int flags)
976 struct sock *sk = sock->sk;
977 struct alg_sock *ask = alg_sk(sk);
978 struct af_alg_ctx *ctx = ask->private;
979 struct af_alg_tsgl *sgl;
982 if (flags & MSG_SENDPAGE_NOTLAST)
986 if (!ctx->more && ctx->used)
992 if (!af_alg_writable(sk)) {
993 err = af_alg_wait_for_wmem(sk, flags);
998 err = af_alg_alloc_tsgl(sk);
1003 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1006 sg_unmark_end(sgl->sg + sgl->cur - 1);
1008 sg_mark_end(sgl->sg + sgl->cur);
1011 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1016 ctx->more = flags & MSG_MORE;
1019 af_alg_data_wakeup(sk);
1024 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1027 * af_alg_free_resources - release resources required for crypto request
1029 void af_alg_free_resources(struct af_alg_async_req *areq)
1031 struct sock *sk = areq->sk;
1033 af_alg_free_areq_sgls(areq);
1034 sock_kfree_s(sk, areq, areq->areqlen);
1036 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1039 * af_alg_async_cb - AIO callback handler
1041 * This handler cleans up the struct af_alg_async_req upon completion of the
1044 * The number of bytes to be generated with the AIO operation must be set
1045 * in areq->outlen before the AIO callback handler is invoked.
1047 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1049 struct af_alg_async_req *areq = _req->data;
1050 struct sock *sk = areq->sk;
1051 struct kiocb *iocb = areq->iocb;
1052 unsigned int resultlen;
1054 /* Buffer size written by crypto operation. */
1055 resultlen = areq->outlen;
1057 af_alg_free_resources(areq);
1060 iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
1062 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1065 * af_alg_poll - poll system call handler
1067 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1070 struct sock *sk = sock->sk;
1071 struct alg_sock *ask = alg_sk(sk);
1072 struct af_alg_ctx *ctx = ask->private;
1075 sock_poll_wait(file, sock, wait);
1078 if (!ctx->more || ctx->used)
1079 mask |= EPOLLIN | EPOLLRDNORM;
1081 if (af_alg_writable(sk))
1082 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1086 EXPORT_SYMBOL_GPL(af_alg_poll);
1089 * af_alg_alloc_areq - allocate struct af_alg_async_req
1091 * @sk socket of connection to user space
1092 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1093 * @return allocated data structure or ERR_PTR upon error
1095 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1096 unsigned int areqlen)
1098 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1100 if (unlikely(!areq))
1101 return ERR_PTR(-ENOMEM);
1103 areq->areqlen = areqlen;
1105 areq->last_rsgl = NULL;
1106 INIT_LIST_HEAD(&areq->rsgl_list);
1108 areq->tsgl_entries = 0;
1112 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1115 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1118 * @sk socket of connection to user space
1119 * @msg user space message
1120 * @flags flags used to invoke recvmsg with
1121 * @areq instance of the cryptographic request that will hold the RX SGL
1122 * @maxsize maximum number of bytes to be pulled from user space
1123 * @outlen number of bytes in the RX SGL
1124 * @return 0 on success, < 0 upon error
1126 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1127 struct af_alg_async_req *areq, size_t maxsize,
1130 struct alg_sock *ask = alg_sk(sk);
1131 struct af_alg_ctx *ctx = ask->private;
1134 while (maxsize > len && msg_data_left(msg)) {
1135 struct af_alg_rsgl *rsgl;
1139 /* limit the amount of readable buffers */
1140 if (!af_alg_readable(sk))
1143 seglen = min_t(size_t, (maxsize - len),
1144 msg_data_left(msg));
1146 if (list_empty(&areq->rsgl_list)) {
1147 rsgl = &areq->first_rsgl;
1149 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1150 if (unlikely(!rsgl))
1154 rsgl->sgl.npages = 0;
1155 list_add_tail(&rsgl->list, &areq->rsgl_list);
1157 /* make one iovec available as scatterlist */
1158 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1160 rsgl->sg_num_bytes = 0;
1164 /* chain the new scatterlist with previous one */
1165 if (areq->last_rsgl)
1166 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1168 areq->last_rsgl = rsgl;
1170 atomic_add(err, &ctx->rcvused);
1171 rsgl->sg_num_bytes = err;
1172 iov_iter_advance(&msg->msg_iter, err);
1178 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1180 static int __init af_alg_init(void)
1182 int err = proto_register(&alg_proto, 0);
1187 err = sock_register(&alg_family);
1189 goto out_unregister_proto;
1194 out_unregister_proto:
1195 proto_unregister(&alg_proto);
1199 static void __exit af_alg_exit(void)
1201 sock_unregister(PF_ALG);
1202 proto_unregister(&alg_proto);
1205 module_init(af_alg_init);
1206 module_exit(af_alg_exit);
1207 MODULE_LICENSE("GPL");
1208 MODULE_ALIAS_NETPROTO(AF_ALG);