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/signal.h>
20 #include <linux/security.h>
22 struct alg_type_list {
23 const struct af_alg_type *type;
24 struct list_head list;
27 static atomic_long_t alg_memory_allocated;
29 static struct proto alg_proto = {
32 .memory_allocated = &alg_memory_allocated,
33 .obj_size = sizeof(struct alg_sock),
36 static LIST_HEAD(alg_types);
37 static DECLARE_RWSEM(alg_types_sem);
39 static const struct af_alg_type *alg_get_type(const char *name)
41 const struct af_alg_type *type = ERR_PTR(-ENOENT);
42 struct alg_type_list *node;
44 down_read(&alg_types_sem);
45 list_for_each_entry(node, &alg_types, list) {
46 if (strcmp(node->type->name, name))
49 if (try_module_get(node->type->owner))
53 up_read(&alg_types_sem);
58 int af_alg_register_type(const struct af_alg_type *type)
60 struct alg_type_list *node;
63 down_write(&alg_types_sem);
64 list_for_each_entry(node, &alg_types, list) {
65 if (!strcmp(node->type->name, type->name))
69 node = kmalloc(sizeof(*node), GFP_KERNEL);
74 type->ops->owner = THIS_MODULE;
76 type->ops_nokey->owner = THIS_MODULE;
78 list_add(&node->list, &alg_types);
82 up_write(&alg_types_sem);
86 EXPORT_SYMBOL_GPL(af_alg_register_type);
88 int af_alg_unregister_type(const struct af_alg_type *type)
90 struct alg_type_list *node;
93 down_write(&alg_types_sem);
94 list_for_each_entry(node, &alg_types, list) {
95 if (strcmp(node->type->name, type->name))
98 list_del(&node->list);
103 up_write(&alg_types_sem);
107 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
109 static void alg_do_release(const struct af_alg_type *type, void *private)
114 type->release(private);
115 module_put(type->owner);
118 int af_alg_release(struct socket *sock)
126 EXPORT_SYMBOL_GPL(af_alg_release);
128 void af_alg_release_parent(struct sock *sk)
130 struct alg_sock *ask = alg_sk(sk);
131 unsigned int nokey = atomic_read(&ask->nokey_refcnt);
137 atomic_dec(&ask->nokey_refcnt);
139 if (atomic_dec_and_test(&ask->refcnt))
142 EXPORT_SYMBOL_GPL(af_alg_release_parent);
144 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
146 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
147 struct sock *sk = sock->sk;
148 struct alg_sock *ask = alg_sk(sk);
149 struct sockaddr_alg *sa = (void *)uaddr;
150 const struct af_alg_type *type;
154 if (sock->state == SS_CONNECTED)
157 if (addr_len < sizeof(*sa))
160 /* If caller uses non-allowed flag, return error. */
161 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
164 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
165 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
167 type = alg_get_type(sa->salg_type);
168 if (PTR_ERR(type) == -ENOENT) {
169 request_module("algif-%s", sa->salg_type);
170 type = alg_get_type(sa->salg_type);
174 return PTR_ERR(type);
176 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
177 if (IS_ERR(private)) {
178 module_put(type->owner);
179 return PTR_ERR(private);
184 if (atomic_read(&ask->refcnt))
187 swap(ask->type, type);
188 swap(ask->private, private);
195 alg_do_release(type, private);
200 static int alg_setkey(struct sock *sk, char __user *ukey,
203 struct alg_sock *ask = alg_sk(sk);
204 const struct af_alg_type *type = ask->type;
208 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
213 if (copy_from_user(key, ukey, keylen))
216 err = type->setkey(ask->private, key, keylen);
219 sock_kzfree_s(sk, key, keylen);
224 static int alg_setsockopt(struct socket *sock, int level, int optname,
225 char __user *optval, unsigned int optlen)
227 struct sock *sk = sock->sk;
228 struct alg_sock *ask = alg_sk(sk);
229 const struct af_alg_type *type;
233 if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt))
239 if (level != SOL_ALG || !type)
244 if (sock->state == SS_CONNECTED)
249 err = alg_setkey(sk, optval, optlen);
251 case ALG_SET_AEAD_AUTHSIZE:
252 if (sock->state == SS_CONNECTED)
254 if (!type->setauthsize)
256 err = type->setauthsize(ask->private, optlen);
265 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
267 struct alg_sock *ask = alg_sk(sk);
268 const struct af_alg_type *type;
280 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
285 sock_init_data(newsock, sk2);
286 security_sock_graft(sk2, newsock);
287 security_sk_clone(sk, sk2);
289 err = type->accept(ask->private, sk2);
291 nokey = err == -ENOKEY;
292 if (nokey && type->accept_nokey)
293 err = type->accept_nokey(ask->private, sk2);
298 if (atomic_inc_return_relaxed(&ask->refcnt) == 1)
301 atomic_inc(&ask->nokey_refcnt);
302 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
304 alg_sk(sk2)->parent = sk;
305 alg_sk(sk2)->type = type;
307 newsock->ops = type->ops;
308 newsock->state = SS_CONNECTED;
311 newsock->ops = type->ops_nokey;
320 EXPORT_SYMBOL_GPL(af_alg_accept);
322 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
325 return af_alg_accept(sock->sk, newsock, kern);
328 static const struct proto_ops alg_proto_ops = {
330 .owner = THIS_MODULE,
332 .connect = sock_no_connect,
333 .socketpair = sock_no_socketpair,
334 .getname = sock_no_getname,
335 .ioctl = sock_no_ioctl,
336 .listen = sock_no_listen,
337 .shutdown = sock_no_shutdown,
338 .getsockopt = sock_no_getsockopt,
339 .mmap = sock_no_mmap,
340 .sendpage = sock_no_sendpage,
341 .sendmsg = sock_no_sendmsg,
342 .recvmsg = sock_no_recvmsg,
345 .release = af_alg_release,
346 .setsockopt = alg_setsockopt,
347 .accept = alg_accept,
350 static void alg_sock_destruct(struct sock *sk)
352 struct alg_sock *ask = alg_sk(sk);
354 alg_do_release(ask->type, ask->private);
357 static int alg_create(struct net *net, struct socket *sock, int protocol,
363 if (sock->type != SOCK_SEQPACKET)
364 return -ESOCKTNOSUPPORT;
366 return -EPROTONOSUPPORT;
369 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
373 sock->ops = &alg_proto_ops;
374 sock_init_data(sock, sk);
376 sk->sk_destruct = alg_sock_destruct;
383 static const struct net_proto_family alg_family = {
385 .create = alg_create,
386 .owner = THIS_MODULE,
389 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
395 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
399 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
400 if (WARN_ON(npages == 0))
402 /* Add one extra for linking */
403 sg_init_table(sgl->sg, npages + 1);
405 for (i = 0, len = n; i < npages; i++) {
406 int plen = min_t(int, len, PAGE_SIZE - off);
408 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
413 sg_mark_end(sgl->sg + npages - 1);
414 sgl->npages = npages;
418 EXPORT_SYMBOL_GPL(af_alg_make_sg);
420 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
421 struct af_alg_sgl *sgl_new)
423 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
424 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
427 void af_alg_free_sg(struct af_alg_sgl *sgl)
431 for (i = 0; i < sgl->npages; i++)
432 put_page(sgl->pages[i]);
434 EXPORT_SYMBOL_GPL(af_alg_free_sg);
436 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
438 struct cmsghdr *cmsg;
440 for_each_cmsghdr(cmsg, msg) {
441 if (!CMSG_OK(msg, cmsg))
443 if (cmsg->cmsg_level != SOL_ALG)
446 switch (cmsg->cmsg_type) {
448 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
450 con->iv = (void *)CMSG_DATA(cmsg);
451 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
457 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
459 con->op = *(u32 *)CMSG_DATA(cmsg);
462 case ALG_SET_AEAD_ASSOCLEN:
463 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
465 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
477 * af_alg_alloc_tsgl - allocate the TX SGL
479 * @sk socket of connection to user space
480 * @return: 0 upon success, < 0 upon error
482 static int af_alg_alloc_tsgl(struct sock *sk)
484 struct alg_sock *ask = alg_sk(sk);
485 struct af_alg_ctx *ctx = ask->private;
486 struct af_alg_tsgl *sgl;
487 struct scatterlist *sg = NULL;
489 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
490 if (!list_empty(&ctx->tsgl_list))
493 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
494 sgl = sock_kmalloc(sk,
495 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
500 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
504 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
506 list_add_tail(&sgl->list, &ctx->tsgl_list);
513 * aead_count_tsgl - Count number of TX SG entries
515 * The counting starts from the beginning of the SGL to @bytes. If
516 * an offset is provided, the counting of the SG entries starts at the offset.
518 * @sk socket of connection to user space
519 * @bytes Count the number of SG entries holding given number of bytes.
520 * @offset Start the counting of SG entries from the given offset.
521 * @return Number of TX SG entries found given the constraints
523 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
525 const struct alg_sock *ask = alg_sk(sk);
526 const struct af_alg_ctx *ctx = ask->private;
527 const struct af_alg_tsgl *sgl;
529 unsigned int sgl_count = 0;
534 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
535 const struct scatterlist *sg = sgl->sg;
537 for (i = 0; i < sgl->cur; i++) {
541 if (offset >= sg[i].length) {
542 offset -= sg[i].length;
543 bytes -= sg[i].length;
547 bytes_count = sg[i].length - offset;
552 /* If we have seen requested number of bytes, stop */
553 if (bytes_count >= bytes)
556 bytes -= bytes_count;
562 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
565 * aead_pull_tsgl - Release the specified buffers from TX SGL
567 * If @dst is non-null, reassign the pages to dst. The caller must release
568 * the pages. If @dst_offset is given only reassign the pages to @dst starting
569 * at the @dst_offset (byte). The caller must ensure that @dst is large
570 * enough (e.g. by using af_alg_count_tsgl with the same offset).
572 * @sk socket of connection to user space
573 * @used Number of bytes to pull from TX SGL
574 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
575 * caller must release the buffers in dst.
576 * @dst_offset Reassign the TX SGL from given offset. All buffers before
577 * reaching the offset is released.
579 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
582 struct alg_sock *ask = alg_sk(sk);
583 struct af_alg_ctx *ctx = ask->private;
584 struct af_alg_tsgl *sgl;
585 struct scatterlist *sg;
586 unsigned int i, j = 0;
588 while (!list_empty(&ctx->tsgl_list)) {
589 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
593 for (i = 0; i < sgl->cur; i++) {
594 size_t plen = min_t(size_t, used, sg[i].length);
595 struct page *page = sg_page(sg + i);
601 * Assumption: caller created af_alg_count_tsgl(len)
605 if (dst_offset >= plen) {
606 /* discard page before offset */
609 /* reassign page to dst after offset */
611 sg_set_page(dst + j, page,
613 sg[i].offset + dst_offset);
619 sg[i].length -= plen;
620 sg[i].offset += plen;
629 sg_assign_page(sg + i, NULL);
632 list_del(&sgl->list);
633 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
639 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
642 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
644 * @areq Request holding the TX and RX SGL
646 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
648 struct sock *sk = areq->sk;
649 struct alg_sock *ask = alg_sk(sk);
650 struct af_alg_ctx *ctx = ask->private;
651 struct af_alg_rsgl *rsgl, *tmp;
652 struct scatterlist *tsgl;
653 struct scatterlist *sg;
656 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
657 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
658 af_alg_free_sg(&rsgl->sgl);
659 list_del(&rsgl->list);
660 if (rsgl != &areq->first_rsgl)
661 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
666 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
669 put_page(sg_page(sg));
672 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
677 * af_alg_wait_for_wmem - wait for availability of writable memory
679 * @sk socket of connection to user space
680 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
681 * @return 0 when writable memory is available, < 0 upon error
683 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
685 DEFINE_WAIT_FUNC(wait, woken_wake_function);
686 int err = -ERESTARTSYS;
689 if (flags & MSG_DONTWAIT)
692 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
694 add_wait_queue(sk_sleep(sk), &wait);
696 if (signal_pending(current))
698 timeout = MAX_SCHEDULE_TIMEOUT;
699 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
704 remove_wait_queue(sk_sleep(sk), &wait);
710 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
712 * @sk socket of connection to user space
714 void af_alg_wmem_wakeup(struct sock *sk)
716 struct socket_wq *wq;
718 if (!af_alg_writable(sk))
722 wq = rcu_dereference(sk->sk_wq);
723 if (skwq_has_sleeper(wq))
724 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
727 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
730 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
733 * af_alg_wait_for_data - wait for availability of TX data
735 * @sk socket of connection to user space
736 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
737 * @return 0 when writable memory is available, < 0 upon error
739 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
741 DEFINE_WAIT_FUNC(wait, woken_wake_function);
742 struct alg_sock *ask = alg_sk(sk);
743 struct af_alg_ctx *ctx = ask->private;
745 int err = -ERESTARTSYS;
747 if (flags & MSG_DONTWAIT)
750 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
752 add_wait_queue(sk_sleep(sk), &wait);
754 if (signal_pending(current))
756 timeout = MAX_SCHEDULE_TIMEOUT;
757 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
763 remove_wait_queue(sk_sleep(sk), &wait);
765 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
769 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
772 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
774 * @sk socket of connection to user space
776 static void af_alg_data_wakeup(struct sock *sk)
778 struct alg_sock *ask = alg_sk(sk);
779 struct af_alg_ctx *ctx = ask->private;
780 struct socket_wq *wq;
786 wq = rcu_dereference(sk->sk_wq);
787 if (skwq_has_sleeper(wq))
788 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
791 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
796 * af_alg_sendmsg - implementation of sendmsg system call handler
798 * The sendmsg system call handler obtains the user data and stores it
799 * in ctx->tsgl_list. This implies allocation of the required numbers of
800 * struct af_alg_tsgl.
802 * In addition, the ctx is filled with the information sent via CMSG.
804 * @sock socket of connection to user space
805 * @msg message from user space
806 * @size size of message from user space
807 * @ivsize the size of the IV for the cipher operation to verify that the
808 * user-space-provided IV has the right size
809 * @return the number of copied data upon success, < 0 upon error
811 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
814 struct sock *sk = sock->sk;
815 struct alg_sock *ask = alg_sk(sk);
816 struct af_alg_ctx *ctx = ask->private;
817 struct af_alg_tsgl *sgl;
818 struct af_alg_control con = {};
824 if (msg->msg_controllen) {
825 err = af_alg_cmsg_send(msg, &con);
841 if (con.iv && con.iv->ivlen != ivsize)
846 if (!ctx->more && ctx->used) {
854 memcpy(ctx->iv, con.iv->iv, ivsize);
856 ctx->aead_assoclen = con.aead_assoclen;
860 struct scatterlist *sg;
864 /* use the existing memory in an allocated page */
866 sgl = list_entry(ctx->tsgl_list.prev,
867 struct af_alg_tsgl, list);
868 sg = sgl->sg + sgl->cur - 1;
869 len = min_t(size_t, len,
870 PAGE_SIZE - sg->offset - sg->length);
872 err = memcpy_from_msg(page_address(sg_page(sg)) +
873 sg->offset + sg->length,
879 ctx->merge = (sg->offset + sg->length) &
888 if (!af_alg_writable(sk)) {
889 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
894 /* allocate a new page */
895 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
897 err = af_alg_alloc_tsgl(sk);
901 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
905 sg_unmark_end(sg + sgl->cur - 1);
908 unsigned int i = sgl->cur;
910 plen = min_t(size_t, len, PAGE_SIZE);
912 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
913 if (!sg_page(sg + i)) {
918 err = memcpy_from_msg(page_address(sg_page(sg + i)),
921 __free_page(sg_page(sg + i));
922 sg_assign_page(sg + i, NULL);
932 } while (len && sgl->cur < MAX_SGL_ENTS);
935 sg_mark_end(sg + sgl->cur - 1);
937 ctx->merge = plen & (PAGE_SIZE - 1);
942 ctx->more = msg->msg_flags & MSG_MORE;
945 af_alg_data_wakeup(sk);
948 return copied ?: err;
950 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
953 * af_alg_sendpage - sendpage system call handler
955 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
957 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
958 int offset, size_t size, int flags)
960 struct sock *sk = sock->sk;
961 struct alg_sock *ask = alg_sk(sk);
962 struct af_alg_ctx *ctx = ask->private;
963 struct af_alg_tsgl *sgl;
966 if (flags & MSG_SENDPAGE_NOTLAST)
970 if (!ctx->more && ctx->used)
976 if (!af_alg_writable(sk)) {
977 err = af_alg_wait_for_wmem(sk, flags);
982 err = af_alg_alloc_tsgl(sk);
987 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
990 sg_unmark_end(sgl->sg + sgl->cur - 1);
992 sg_mark_end(sgl->sg + sgl->cur);
995 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1000 ctx->more = flags & MSG_MORE;
1003 af_alg_data_wakeup(sk);
1008 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1011 * af_alg_free_resources - release resources required for crypto request
1013 void af_alg_free_resources(struct af_alg_async_req *areq)
1015 struct sock *sk = areq->sk;
1017 af_alg_free_areq_sgls(areq);
1018 sock_kfree_s(sk, areq, areq->areqlen);
1020 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1023 * af_alg_async_cb - AIO callback handler
1025 * This handler cleans up the struct af_alg_async_req upon completion of the
1028 * The number of bytes to be generated with the AIO operation must be set
1029 * in areq->outlen before the AIO callback handler is invoked.
1031 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1033 struct af_alg_async_req *areq = _req->data;
1034 struct sock *sk = areq->sk;
1035 struct kiocb *iocb = areq->iocb;
1036 unsigned int resultlen;
1038 /* Buffer size written by crypto operation. */
1039 resultlen = areq->outlen;
1041 af_alg_free_resources(areq);
1044 iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
1046 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1049 * af_alg_poll - poll system call handler
1051 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1054 struct sock *sk = sock->sk;
1055 struct alg_sock *ask = alg_sk(sk);
1056 struct af_alg_ctx *ctx = ask->private;
1059 sock_poll_wait(file, sock, wait);
1062 if (!ctx->more || ctx->used)
1063 mask |= EPOLLIN | EPOLLRDNORM;
1065 if (af_alg_writable(sk))
1066 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1070 EXPORT_SYMBOL_GPL(af_alg_poll);
1073 * af_alg_alloc_areq - allocate struct af_alg_async_req
1075 * @sk socket of connection to user space
1076 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1077 * @return allocated data structure or ERR_PTR upon error
1079 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1080 unsigned int areqlen)
1082 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1084 if (unlikely(!areq))
1085 return ERR_PTR(-ENOMEM);
1087 areq->areqlen = areqlen;
1089 areq->last_rsgl = NULL;
1090 INIT_LIST_HEAD(&areq->rsgl_list);
1092 areq->tsgl_entries = 0;
1096 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1099 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1102 * @sk socket of connection to user space
1103 * @msg user space message
1104 * @flags flags used to invoke recvmsg with
1105 * @areq instance of the cryptographic request that will hold the RX SGL
1106 * @maxsize maximum number of bytes to be pulled from user space
1107 * @outlen number of bytes in the RX SGL
1108 * @return 0 on success, < 0 upon error
1110 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1111 struct af_alg_async_req *areq, size_t maxsize,
1114 struct alg_sock *ask = alg_sk(sk);
1115 struct af_alg_ctx *ctx = ask->private;
1118 while (maxsize > len && msg_data_left(msg)) {
1119 struct af_alg_rsgl *rsgl;
1123 /* limit the amount of readable buffers */
1124 if (!af_alg_readable(sk))
1127 seglen = min_t(size_t, (maxsize - len),
1128 msg_data_left(msg));
1130 if (list_empty(&areq->rsgl_list)) {
1131 rsgl = &areq->first_rsgl;
1133 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1134 if (unlikely(!rsgl))
1138 rsgl->sgl.npages = 0;
1139 list_add_tail(&rsgl->list, &areq->rsgl_list);
1141 /* make one iovec available as scatterlist */
1142 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1144 rsgl->sg_num_bytes = 0;
1148 /* chain the new scatterlist with previous one */
1149 if (areq->last_rsgl)
1150 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1152 areq->last_rsgl = rsgl;
1154 atomic_add(err, &ctx->rcvused);
1155 rsgl->sg_num_bytes = err;
1156 iov_iter_advance(&msg->msg_iter, err);
1162 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1164 static int __init af_alg_init(void)
1166 int err = proto_register(&alg_proto, 0);
1171 err = sock_register(&alg_family);
1173 goto out_unregister_proto;
1178 out_unregister_proto:
1179 proto_unregister(&alg_proto);
1183 static void __exit af_alg_exit(void)
1185 sock_unregister(PF_ALG);
1186 proto_unregister(&alg_proto);
1189 module_init(af_alg_init);
1190 module_exit(af_alg_exit);
1191 MODULE_LICENSE("GPL");
1192 MODULE_ALIAS_NETPROTO(AF_ALG);