2 * af_alg: User-space algorithm interface
4 * This file provides the user-space API for algorithms.
6 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
15 #include <linux/atomic.h>
16 #include <crypto/if_alg.h>
17 #include <linux/crypto.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/list.h>
21 #include <linux/module.h>
22 #include <linux/net.h>
23 #include <linux/rwsem.h>
24 #include <linux/sched/signal.h>
25 #include <linux/security.h>
27 struct alg_type_list {
28 const struct af_alg_type *type;
29 struct list_head list;
32 static atomic_long_t alg_memory_allocated;
34 static struct proto alg_proto = {
37 .memory_allocated = &alg_memory_allocated,
38 .obj_size = sizeof(struct alg_sock),
41 static LIST_HEAD(alg_types);
42 static DECLARE_RWSEM(alg_types_sem);
44 static const struct af_alg_type *alg_get_type(const char *name)
46 const struct af_alg_type *type = ERR_PTR(-ENOENT);
47 struct alg_type_list *node;
49 down_read(&alg_types_sem);
50 list_for_each_entry(node, &alg_types, list) {
51 if (strcmp(node->type->name, name))
54 if (try_module_get(node->type->owner))
58 up_read(&alg_types_sem);
63 int af_alg_register_type(const struct af_alg_type *type)
65 struct alg_type_list *node;
68 down_write(&alg_types_sem);
69 list_for_each_entry(node, &alg_types, list) {
70 if (!strcmp(node->type->name, type->name))
74 node = kmalloc(sizeof(*node), GFP_KERNEL);
79 type->ops->owner = THIS_MODULE;
81 type->ops_nokey->owner = THIS_MODULE;
83 list_add(&node->list, &alg_types);
87 up_write(&alg_types_sem);
91 EXPORT_SYMBOL_GPL(af_alg_register_type);
93 int af_alg_unregister_type(const struct af_alg_type *type)
95 struct alg_type_list *node;
98 down_write(&alg_types_sem);
99 list_for_each_entry(node, &alg_types, list) {
100 if (strcmp(node->type->name, type->name))
103 list_del(&node->list);
108 up_write(&alg_types_sem);
112 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
114 static void alg_do_release(const struct af_alg_type *type, void *private)
119 type->release(private);
120 module_put(type->owner);
123 int af_alg_release(struct socket *sock)
131 EXPORT_SYMBOL_GPL(af_alg_release);
133 void af_alg_release_parent(struct sock *sk)
135 struct alg_sock *ask = alg_sk(sk);
136 unsigned int nokey = ask->nokey_refcnt;
137 bool last = nokey && !ask->refcnt;
144 ask->nokey_refcnt -= nokey;
146 last = !--ask->refcnt;
153 EXPORT_SYMBOL_GPL(af_alg_release_parent);
155 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
157 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
158 struct sock *sk = sock->sk;
159 struct alg_sock *ask = alg_sk(sk);
160 struct sockaddr_alg *sa = (void *)uaddr;
161 const struct af_alg_type *type;
165 if (sock->state == SS_CONNECTED)
168 if (addr_len < sizeof(*sa))
171 /* If caller uses non-allowed flag, return error. */
172 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
175 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
176 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
178 type = alg_get_type(sa->salg_type);
179 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
180 request_module("algif-%s", sa->salg_type);
181 type = alg_get_type(sa->salg_type);
185 return PTR_ERR(type);
187 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
188 if (IS_ERR(private)) {
189 module_put(type->owner);
190 return PTR_ERR(private);
195 if (ask->refcnt | ask->nokey_refcnt)
198 swap(ask->type, type);
199 swap(ask->private, private);
206 alg_do_release(type, private);
211 static int alg_setkey(struct sock *sk, char __user *ukey,
214 struct alg_sock *ask = alg_sk(sk);
215 const struct af_alg_type *type = ask->type;
219 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
224 if (copy_from_user(key, ukey, keylen))
227 err = type->setkey(ask->private, key, keylen);
230 sock_kzfree_s(sk, key, keylen);
235 static int alg_setsockopt(struct socket *sock, int level, int optname,
236 char __user *optval, unsigned int optlen)
238 struct sock *sk = sock->sk;
239 struct alg_sock *ask = alg_sk(sk);
240 const struct af_alg_type *type;
250 if (level != SOL_ALG || !type)
255 if (sock->state == SS_CONNECTED)
260 err = alg_setkey(sk, optval, optlen);
262 case ALG_SET_AEAD_AUTHSIZE:
263 if (sock->state == SS_CONNECTED)
265 if (!type->setauthsize)
267 err = type->setauthsize(ask->private, optlen);
276 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
278 struct alg_sock *ask = alg_sk(sk);
279 const struct af_alg_type *type;
291 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
296 sock_init_data(newsock, sk2);
297 security_sock_graft(sk2, newsock);
298 security_sk_clone(sk, sk2);
300 err = type->accept(ask->private, sk2);
302 nokey = err == -ENOKEY;
303 if (nokey && type->accept_nokey)
304 err = type->accept_nokey(ask->private, sk2);
309 sk2->sk_family = PF_ALG;
311 if (nokey || !ask->refcnt++)
313 ask->nokey_refcnt += nokey;
314 alg_sk(sk2)->parent = sk;
315 alg_sk(sk2)->type = type;
316 alg_sk(sk2)->nokey_refcnt = nokey;
318 newsock->ops = type->ops;
319 newsock->state = SS_CONNECTED;
322 newsock->ops = type->ops_nokey;
331 EXPORT_SYMBOL_GPL(af_alg_accept);
333 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
336 return af_alg_accept(sock->sk, newsock, kern);
339 static const struct proto_ops alg_proto_ops = {
341 .owner = THIS_MODULE,
343 .connect = sock_no_connect,
344 .socketpair = sock_no_socketpair,
345 .getname = sock_no_getname,
346 .ioctl = sock_no_ioctl,
347 .listen = sock_no_listen,
348 .shutdown = sock_no_shutdown,
349 .getsockopt = sock_no_getsockopt,
350 .mmap = sock_no_mmap,
351 .sendpage = sock_no_sendpage,
352 .sendmsg = sock_no_sendmsg,
353 .recvmsg = sock_no_recvmsg,
356 .release = af_alg_release,
357 .setsockopt = alg_setsockopt,
358 .accept = alg_accept,
361 static void alg_sock_destruct(struct sock *sk)
363 struct alg_sock *ask = alg_sk(sk);
365 alg_do_release(ask->type, ask->private);
368 static int alg_create(struct net *net, struct socket *sock, int protocol,
374 if (sock->type != SOCK_SEQPACKET)
375 return -ESOCKTNOSUPPORT;
377 return -EPROTONOSUPPORT;
380 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
384 sock->ops = &alg_proto_ops;
385 sock_init_data(sock, sk);
387 sk->sk_family = PF_ALG;
388 sk->sk_destruct = alg_sock_destruct;
395 static const struct net_proto_family alg_family = {
397 .create = alg_create,
398 .owner = THIS_MODULE,
401 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
407 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
411 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
412 if (WARN_ON(npages == 0))
414 /* Add one extra for linking */
415 sg_init_table(sgl->sg, npages + 1);
417 for (i = 0, len = n; i < npages; i++) {
418 int plen = min_t(int, len, PAGE_SIZE - off);
420 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
425 sg_mark_end(sgl->sg + npages - 1);
426 sgl->npages = npages;
430 EXPORT_SYMBOL_GPL(af_alg_make_sg);
432 void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
434 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
435 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
437 EXPORT_SYMBOL_GPL(af_alg_link_sg);
439 void af_alg_free_sg(struct af_alg_sgl *sgl)
443 for (i = 0; i < sgl->npages; i++)
444 put_page(sgl->pages[i]);
446 EXPORT_SYMBOL_GPL(af_alg_free_sg);
448 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
450 struct cmsghdr *cmsg;
452 for_each_cmsghdr(cmsg, msg) {
453 if (!CMSG_OK(msg, cmsg))
455 if (cmsg->cmsg_level != SOL_ALG)
458 switch (cmsg->cmsg_type) {
460 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
462 con->iv = (void *)CMSG_DATA(cmsg);
463 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
469 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
471 con->op = *(u32 *)CMSG_DATA(cmsg);
474 case ALG_SET_AEAD_ASSOCLEN:
475 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
477 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
487 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
490 * af_alg_alloc_tsgl - allocate the TX SGL
492 * @sk socket of connection to user space
493 * @return: 0 upon success, < 0 upon error
495 int af_alg_alloc_tsgl(struct sock *sk)
497 struct alg_sock *ask = alg_sk(sk);
498 struct af_alg_ctx *ctx = ask->private;
499 struct af_alg_tsgl *sgl;
500 struct scatterlist *sg = NULL;
502 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
503 if (!list_empty(&ctx->tsgl_list))
506 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
507 sgl = sock_kmalloc(sk,
508 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
513 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
517 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
519 list_add_tail(&sgl->list, &ctx->tsgl_list);
524 EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl);
527 * aead_count_tsgl - Count number of TX SG entries
529 * The counting starts from the beginning of the SGL to @bytes. If
530 * an offset is provided, the counting of the SG entries starts at the offset.
532 * @sk socket of connection to user space
533 * @bytes Count the number of SG entries holding given number of bytes.
534 * @offset Start the counting of SG entries from the given offset.
535 * @return Number of TX SG entries found given the constraints
537 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
539 struct alg_sock *ask = alg_sk(sk);
540 struct af_alg_ctx *ctx = ask->private;
541 struct af_alg_tsgl *sgl, *tmp;
543 unsigned int sgl_count = 0;
548 list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) {
549 struct scatterlist *sg = sgl->sg;
551 for (i = 0; i < sgl->cur; i++) {
555 if (offset >= sg[i].length) {
556 offset -= sg[i].length;
557 bytes -= sg[i].length;
561 bytes_count = sg[i].length - offset;
566 /* If we have seen requested number of bytes, stop */
567 if (bytes_count >= bytes)
570 bytes -= bytes_count;
576 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
579 * aead_pull_tsgl - Release the specified buffers from TX SGL
581 * If @dst is non-null, reassign the pages to dst. The caller must release
582 * the pages. If @dst_offset is given only reassign the pages to @dst starting
583 * at the @dst_offset (byte). The caller must ensure that @dst is large
584 * enough (e.g. by using af_alg_count_tsgl with the same offset).
586 * @sk socket of connection to user space
587 * @used Number of bytes to pull from TX SGL
588 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
589 * caller must release the buffers in dst.
590 * @dst_offset Reassign the TX SGL from given offset. All buffers before
591 * reaching the offset is released.
593 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
596 struct alg_sock *ask = alg_sk(sk);
597 struct af_alg_ctx *ctx = ask->private;
598 struct af_alg_tsgl *sgl;
599 struct scatterlist *sg;
600 unsigned int i, j = 0;
602 while (!list_empty(&ctx->tsgl_list)) {
603 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
607 for (i = 0; i < sgl->cur; i++) {
608 size_t plen = min_t(size_t, used, sg[i].length);
609 struct page *page = sg_page(sg + i);
615 * Assumption: caller created af_alg_count_tsgl(len)
619 if (dst_offset >= plen) {
620 /* discard page before offset */
623 /* reassign page to dst after offset */
625 sg_set_page(dst + j, page,
627 sg[i].offset + dst_offset);
633 sg[i].length -= plen;
634 sg[i].offset += plen;
643 sg_assign_page(sg + i, NULL);
646 list_del(&sgl->list);
647 sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
654 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
657 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
659 * @areq Request holding the TX and RX SGL
661 void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
663 struct sock *sk = areq->sk;
664 struct alg_sock *ask = alg_sk(sk);
665 struct af_alg_ctx *ctx = ask->private;
666 struct af_alg_rsgl *rsgl, *tmp;
667 struct scatterlist *tsgl;
668 struct scatterlist *sg;
671 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
672 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
673 af_alg_free_sg(&rsgl->sgl);
674 list_del(&rsgl->list);
675 if (rsgl != &areq->first_rsgl)
676 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
681 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
684 put_page(sg_page(sg));
687 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
690 EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);
693 * af_alg_wait_for_wmem - wait for availability of writable memory
695 * @sk socket of connection to user space
696 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
697 * @return 0 when writable memory is available, < 0 upon error
699 int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
701 DEFINE_WAIT_FUNC(wait, woken_wake_function);
702 int err = -ERESTARTSYS;
705 if (flags & MSG_DONTWAIT)
708 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
710 add_wait_queue(sk_sleep(sk), &wait);
712 if (signal_pending(current))
714 timeout = MAX_SCHEDULE_TIMEOUT;
715 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
720 remove_wait_queue(sk_sleep(sk), &wait);
724 EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem);
727 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
729 * @sk socket of connection to user space
731 void af_alg_wmem_wakeup(struct sock *sk)
733 struct socket_wq *wq;
735 if (!af_alg_writable(sk))
739 wq = rcu_dereference(sk->sk_wq);
740 if (skwq_has_sleeper(wq))
741 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
744 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
747 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
750 * af_alg_wait_for_data - wait for availability of TX data
752 * @sk socket of connection to user space
753 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
754 * @return 0 when writable memory is available, < 0 upon error
756 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
758 DEFINE_WAIT_FUNC(wait, woken_wake_function);
759 struct alg_sock *ask = alg_sk(sk);
760 struct af_alg_ctx *ctx = ask->private;
762 int err = -ERESTARTSYS;
764 if (flags & MSG_DONTWAIT)
767 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
769 add_wait_queue(sk_sleep(sk), &wait);
771 if (signal_pending(current))
773 timeout = MAX_SCHEDULE_TIMEOUT;
774 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
780 remove_wait_queue(sk_sleep(sk), &wait);
782 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
786 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
789 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
791 * @sk socket of connection to user space
794 void af_alg_data_wakeup(struct sock *sk)
796 struct alg_sock *ask = alg_sk(sk);
797 struct af_alg_ctx *ctx = ask->private;
798 struct socket_wq *wq;
804 wq = rcu_dereference(sk->sk_wq);
805 if (skwq_has_sleeper(wq))
806 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
809 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
812 EXPORT_SYMBOL_GPL(af_alg_data_wakeup);
815 * af_alg_sendmsg - implementation of sendmsg system call handler
817 * The sendmsg system call handler obtains the user data and stores it
818 * in ctx->tsgl_list. This implies allocation of the required numbers of
819 * struct af_alg_tsgl.
821 * In addition, the ctx is filled with the information sent via CMSG.
823 * @sock socket of connection to user space
824 * @msg message from user space
825 * @size size of message from user space
826 * @ivsize the size of the IV for the cipher operation to verify that the
827 * user-space-provided IV has the right size
828 * @return the number of copied data upon success, < 0 upon error
830 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
833 struct sock *sk = sock->sk;
834 struct alg_sock *ask = alg_sk(sk);
835 struct af_alg_ctx *ctx = ask->private;
836 struct af_alg_tsgl *sgl;
837 struct af_alg_control con = {};
843 if (msg->msg_controllen) {
844 err = af_alg_cmsg_send(msg, &con);
860 if (con.iv && con.iv->ivlen != ivsize)
865 if (!ctx->more && ctx->used) {
873 memcpy(ctx->iv, con.iv->iv, ivsize);
875 ctx->aead_assoclen = con.aead_assoclen;
879 struct scatterlist *sg;
883 /* use the existing memory in an allocated page */
885 sgl = list_entry(ctx->tsgl_list.prev,
886 struct af_alg_tsgl, list);
887 sg = sgl->sg + sgl->cur - 1;
888 len = min_t(size_t, len,
889 PAGE_SIZE - sg->offset - sg->length);
891 err = memcpy_from_msg(page_address(sg_page(sg)) +
892 sg->offset + sg->length,
898 ctx->merge = (sg->offset + sg->length) &
907 if (!af_alg_writable(sk)) {
908 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
913 /* allocate a new page */
914 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
916 err = af_alg_alloc_tsgl(sk);
920 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
924 sg_unmark_end(sg + sgl->cur - 1);
927 unsigned int i = sgl->cur;
929 plen = min_t(size_t, len, PAGE_SIZE);
931 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
932 if (!sg_page(sg + i)) {
937 err = memcpy_from_msg(page_address(sg_page(sg + i)),
940 __free_page(sg_page(sg + i));
941 sg_assign_page(sg + i, NULL);
951 } while (len && sgl->cur < MAX_SGL_ENTS);
954 sg_mark_end(sg + sgl->cur - 1);
956 ctx->merge = plen & (PAGE_SIZE - 1);
961 ctx->more = msg->msg_flags & MSG_MORE;
964 af_alg_data_wakeup(sk);
967 return copied ?: err;
969 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
972 * af_alg_sendpage - sendpage system call handler
974 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
976 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
977 int offset, size_t size, int flags)
979 struct sock *sk = sock->sk;
980 struct alg_sock *ask = alg_sk(sk);
981 struct af_alg_ctx *ctx = ask->private;
982 struct af_alg_tsgl *sgl;
985 if (flags & MSG_SENDPAGE_NOTLAST)
989 if (!ctx->more && ctx->used)
995 if (!af_alg_writable(sk)) {
996 err = af_alg_wait_for_wmem(sk, flags);
1001 err = af_alg_alloc_tsgl(sk);
1006 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1009 sg_unmark_end(sgl->sg + sgl->cur - 1);
1011 sg_mark_end(sgl->sg + sgl->cur);
1014 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1019 ctx->more = flags & MSG_MORE;
1022 af_alg_data_wakeup(sk);
1027 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1030 * af_alg_free_resources - release resources required for crypto request
1032 void af_alg_free_resources(struct af_alg_async_req *areq)
1034 struct sock *sk = areq->sk;
1036 af_alg_free_areq_sgls(areq);
1037 sock_kfree_s(sk, areq, areq->areqlen);
1039 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1042 * af_alg_async_cb - AIO callback handler
1044 * This handler cleans up the struct af_alg_async_req upon completion of the
1047 * The number of bytes to be generated with the AIO operation must be set
1048 * in areq->outlen before the AIO callback handler is invoked.
1050 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1052 struct af_alg_async_req *areq = _req->data;
1053 struct sock *sk = areq->sk;
1054 struct kiocb *iocb = areq->iocb;
1055 unsigned int resultlen;
1057 /* Buffer size written by crypto operation. */
1058 resultlen = areq->outlen;
1060 af_alg_free_resources(areq);
1063 iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
1065 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1068 * af_alg_poll - poll system call handler
1070 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1073 struct sock *sk = sock->sk;
1074 struct alg_sock *ask = alg_sk(sk);
1075 struct af_alg_ctx *ctx = ask->private;
1078 sock_poll_wait(file, sock, wait);
1081 if (!ctx->more || ctx->used)
1082 mask |= EPOLLIN | EPOLLRDNORM;
1084 if (af_alg_writable(sk))
1085 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1089 EXPORT_SYMBOL_GPL(af_alg_poll);
1092 * af_alg_alloc_areq - allocate struct af_alg_async_req
1094 * @sk socket of connection to user space
1095 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1096 * @return allocated data structure or ERR_PTR upon error
1098 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1099 unsigned int areqlen)
1101 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1103 if (unlikely(!areq))
1104 return ERR_PTR(-ENOMEM);
1106 areq->areqlen = areqlen;
1108 areq->last_rsgl = NULL;
1109 INIT_LIST_HEAD(&areq->rsgl_list);
1111 areq->tsgl_entries = 0;
1115 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1118 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1121 * @sk socket of connection to user space
1122 * @msg user space message
1123 * @flags flags used to invoke recvmsg with
1124 * @areq instance of the cryptographic request that will hold the RX SGL
1125 * @maxsize maximum number of bytes to be pulled from user space
1126 * @outlen number of bytes in the RX SGL
1127 * @return 0 on success, < 0 upon error
1129 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1130 struct af_alg_async_req *areq, size_t maxsize,
1133 struct alg_sock *ask = alg_sk(sk);
1134 struct af_alg_ctx *ctx = ask->private;
1137 while (maxsize > len && msg_data_left(msg)) {
1138 struct af_alg_rsgl *rsgl;
1142 /* limit the amount of readable buffers */
1143 if (!af_alg_readable(sk))
1146 seglen = min_t(size_t, (maxsize - len),
1147 msg_data_left(msg));
1149 if (list_empty(&areq->rsgl_list)) {
1150 rsgl = &areq->first_rsgl;
1152 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1153 if (unlikely(!rsgl))
1157 rsgl->sgl.npages = 0;
1158 list_add_tail(&rsgl->list, &areq->rsgl_list);
1160 /* make one iovec available as scatterlist */
1161 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1163 rsgl->sg_num_bytes = 0;
1167 /* chain the new scatterlist with previous one */
1168 if (areq->last_rsgl)
1169 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1171 areq->last_rsgl = rsgl;
1173 atomic_add(err, &ctx->rcvused);
1174 rsgl->sg_num_bytes = err;
1175 iov_iter_advance(&msg->msg_iter, err);
1181 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1183 static int __init af_alg_init(void)
1185 int err = proto_register(&alg_proto, 0);
1190 err = sock_register(&alg_family);
1192 goto out_unregister_proto;
1197 out_unregister_proto:
1198 proto_unregister(&alg_proto);
1202 static void __exit af_alg_exit(void)
1204 sock_unregister(PF_ALG);
1205 proto_unregister(&alg_proto);
1208 module_init(af_alg_init);
1209 module_exit(af_alg_exit);
1210 MODULE_LICENSE("GPL");
1211 MODULE_ALIAS_NETPROTO(AF_ALG);