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
;
143 ask
->nokey_refcnt
-= nokey
;
145 last
= !--ask
->refcnt
;
151 EXPORT_SYMBOL_GPL(af_alg_release_parent
);
153 static int alg_bind(struct socket
*sock
, struct sockaddr
*uaddr
, int addr_len
)
155 const u32 allowed
= CRYPTO_ALG_KERN_DRIVER_ONLY
;
156 struct sock
*sk
= sock
->sk
;
157 struct alg_sock
*ask
= alg_sk(sk
);
158 struct sockaddr_alg
*sa
= (void *)uaddr
;
159 const struct af_alg_type
*type
;
163 if (sock
->state
== SS_CONNECTED
)
166 if (addr_len
< sizeof(*sa
))
169 /* If caller uses non-allowed flag, return error. */
170 if ((sa
->salg_feat
& ~allowed
) || (sa
->salg_mask
& ~allowed
))
173 sa
->salg_type
[sizeof(sa
->salg_type
) - 1] = 0;
174 sa
->salg_name
[sizeof(sa
->salg_name
) + addr_len
- sizeof(*sa
) - 1] = 0;
176 type
= alg_get_type(sa
->salg_type
);
177 if (IS_ERR(type
) && PTR_ERR(type
) == -ENOENT
) {
178 request_module("algif-%s", sa
->salg_type
);
179 type
= alg_get_type(sa
->salg_type
);
183 return PTR_ERR(type
);
185 private = type
->bind(sa
->salg_name
, sa
->salg_feat
, sa
->salg_mask
);
186 if (IS_ERR(private)) {
187 module_put(type
->owner
);
188 return PTR_ERR(private);
193 if (ask
->refcnt
| ask
->nokey_refcnt
)
196 swap(ask
->type
, type
);
197 swap(ask
->private, private);
204 alg_do_release(type
, private);
209 static int alg_setkey(struct sock
*sk
, char __user
*ukey
,
212 struct alg_sock
*ask
= alg_sk(sk
);
213 const struct af_alg_type
*type
= ask
->type
;
217 key
= sock_kmalloc(sk
, keylen
, GFP_KERNEL
);
222 if (copy_from_user(key
, ukey
, keylen
))
225 err
= type
->setkey(ask
->private, key
, keylen
);
228 sock_kzfree_s(sk
, key
, keylen
);
233 static int alg_setsockopt(struct socket
*sock
, int level
, int optname
,
234 char __user
*optval
, unsigned int optlen
)
236 struct sock
*sk
= sock
->sk
;
237 struct alg_sock
*ask
= alg_sk(sk
);
238 const struct af_alg_type
*type
;
248 if (level
!= SOL_ALG
|| !type
)
253 if (sock
->state
== SS_CONNECTED
)
258 err
= alg_setkey(sk
, optval
, optlen
);
260 case ALG_SET_AEAD_AUTHSIZE
:
261 if (sock
->state
== SS_CONNECTED
)
263 if (!type
->setauthsize
)
265 err
= type
->setauthsize(ask
->private, optlen
);
274 int af_alg_accept(struct sock
*sk
, struct socket
*newsock
, bool kern
)
276 struct alg_sock
*ask
= alg_sk(sk
);
277 const struct af_alg_type
*type
;
289 sk2
= sk_alloc(sock_net(sk
), PF_ALG
, GFP_KERNEL
, &alg_proto
, kern
);
294 sock_init_data(newsock
, sk2
);
295 security_sock_graft(sk2
, newsock
);
296 security_sk_clone(sk
, sk2
);
298 err
= type
->accept(ask
->private, sk2
);
300 nokey
= err
== -ENOKEY
;
301 if (nokey
&& type
->accept_nokey
)
302 err
= type
->accept_nokey(ask
->private, sk2
);
307 sk2
->sk_family
= PF_ALG
;
309 if (nokey
|| !ask
->refcnt
++)
311 ask
->nokey_refcnt
+= nokey
;
312 alg_sk(sk2
)->parent
= sk
;
313 alg_sk(sk2
)->type
= type
;
314 alg_sk(sk2
)->nokey_refcnt
= nokey
;
316 newsock
->ops
= type
->ops
;
317 newsock
->state
= SS_CONNECTED
;
320 newsock
->ops
= type
->ops_nokey
;
329 EXPORT_SYMBOL_GPL(af_alg_accept
);
331 static int alg_accept(struct socket
*sock
, struct socket
*newsock
, int flags
,
334 return af_alg_accept(sock
->sk
, newsock
, kern
);
337 static const struct proto_ops alg_proto_ops
= {
339 .owner
= THIS_MODULE
,
341 .connect
= sock_no_connect
,
342 .socketpair
= sock_no_socketpair
,
343 .getname
= sock_no_getname
,
344 .ioctl
= sock_no_ioctl
,
345 .listen
= sock_no_listen
,
346 .shutdown
= sock_no_shutdown
,
347 .getsockopt
= sock_no_getsockopt
,
348 .mmap
= sock_no_mmap
,
349 .sendpage
= sock_no_sendpage
,
350 .sendmsg
= sock_no_sendmsg
,
351 .recvmsg
= sock_no_recvmsg
,
352 .poll
= sock_no_poll
,
355 .release
= af_alg_release
,
356 .setsockopt
= alg_setsockopt
,
357 .accept
= alg_accept
,
360 static void alg_sock_destruct(struct sock
*sk
)
362 struct alg_sock
*ask
= alg_sk(sk
);
364 alg_do_release(ask
->type
, ask
->private);
367 static int alg_create(struct net
*net
, struct socket
*sock
, int protocol
,
373 if (sock
->type
!= SOCK_SEQPACKET
)
374 return -ESOCKTNOSUPPORT
;
376 return -EPROTONOSUPPORT
;
379 sk
= sk_alloc(net
, PF_ALG
, GFP_KERNEL
, &alg_proto
, kern
);
383 sock
->ops
= &alg_proto_ops
;
384 sock_init_data(sock
, sk
);
386 sk
->sk_family
= PF_ALG
;
387 sk
->sk_destruct
= alg_sock_destruct
;
394 static const struct net_proto_family alg_family
= {
396 .create
= alg_create
,
397 .owner
= THIS_MODULE
,
400 int af_alg_make_sg(struct af_alg_sgl
*sgl
, struct iov_iter
*iter
, int len
)
406 n
= iov_iter_get_pages(iter
, sgl
->pages
, len
, ALG_MAX_PAGES
, &off
);
410 npages
= (off
+ n
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
411 if (WARN_ON(npages
== 0))
413 /* Add one extra for linking */
414 sg_init_table(sgl
->sg
, npages
+ 1);
416 for (i
= 0, len
= n
; i
< npages
; i
++) {
417 int plen
= min_t(int, len
, PAGE_SIZE
- off
);
419 sg_set_page(sgl
->sg
+ i
, sgl
->pages
[i
], plen
, off
);
424 sg_mark_end(sgl
->sg
+ npages
- 1);
425 sgl
->npages
= npages
;
429 EXPORT_SYMBOL_GPL(af_alg_make_sg
);
431 void af_alg_link_sg(struct af_alg_sgl
*sgl_prev
, struct af_alg_sgl
*sgl_new
)
433 sg_unmark_end(sgl_prev
->sg
+ sgl_prev
->npages
- 1);
434 sg_chain(sgl_prev
->sg
, sgl_prev
->npages
+ 1, sgl_new
->sg
);
436 EXPORT_SYMBOL_GPL(af_alg_link_sg
);
438 void af_alg_free_sg(struct af_alg_sgl
*sgl
)
442 for (i
= 0; i
< sgl
->npages
; i
++)
443 put_page(sgl
->pages
[i
]);
445 EXPORT_SYMBOL_GPL(af_alg_free_sg
);
447 int af_alg_cmsg_send(struct msghdr
*msg
, struct af_alg_control
*con
)
449 struct cmsghdr
*cmsg
;
451 for_each_cmsghdr(cmsg
, msg
) {
452 if (!CMSG_OK(msg
, cmsg
))
454 if (cmsg
->cmsg_level
!= SOL_ALG
)
457 switch (cmsg
->cmsg_type
) {
459 if (cmsg
->cmsg_len
< CMSG_LEN(sizeof(*con
->iv
)))
461 con
->iv
= (void *)CMSG_DATA(cmsg
);
462 if (cmsg
->cmsg_len
< CMSG_LEN(con
->iv
->ivlen
+
468 if (cmsg
->cmsg_len
< CMSG_LEN(sizeof(u32
)))
470 con
->op
= *(u32
*)CMSG_DATA(cmsg
);
473 case ALG_SET_AEAD_ASSOCLEN
:
474 if (cmsg
->cmsg_len
< CMSG_LEN(sizeof(u32
)))
476 con
->aead_assoclen
= *(u32
*)CMSG_DATA(cmsg
);
486 EXPORT_SYMBOL_GPL(af_alg_cmsg_send
);
489 * af_alg_alloc_tsgl - allocate the TX SGL
491 * @sk socket of connection to user space
492 * @return: 0 upon success, < 0 upon error
494 int af_alg_alloc_tsgl(struct sock
*sk
)
496 struct alg_sock
*ask
= alg_sk(sk
);
497 struct af_alg_ctx
*ctx
= ask
->private;
498 struct af_alg_tsgl
*sgl
;
499 struct scatterlist
*sg
= NULL
;
501 sgl
= list_entry(ctx
->tsgl_list
.prev
, struct af_alg_tsgl
, list
);
502 if (!list_empty(&ctx
->tsgl_list
))
505 if (!sg
|| sgl
->cur
>= MAX_SGL_ENTS
) {
506 sgl
= sock_kmalloc(sk
, sizeof(*sgl
) +
507 sizeof(sgl
->sg
[0]) * (MAX_SGL_ENTS
+ 1),
512 sg_init_table(sgl
->sg
, MAX_SGL_ENTS
+ 1);
516 sg_chain(sg
, MAX_SGL_ENTS
+ 1, sgl
->sg
);
518 list_add_tail(&sgl
->list
, &ctx
->tsgl_list
);
523 EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl
);
526 * aead_count_tsgl - Count number of TX SG entries
528 * The counting starts from the beginning of the SGL to @bytes. If
529 * an offset is provided, the counting of the SG entries starts at the offset.
531 * @sk socket of connection to user space
532 * @bytes Count the number of SG entries holding given number of bytes.
533 * @offset Start the counting of SG entries from the given offset.
534 * @return Number of TX SG entries found given the constraints
536 unsigned int af_alg_count_tsgl(struct sock
*sk
, size_t bytes
, size_t offset
)
538 struct alg_sock
*ask
= alg_sk(sk
);
539 struct af_alg_ctx
*ctx
= ask
->private;
540 struct af_alg_tsgl
*sgl
, *tmp
;
542 unsigned int sgl_count
= 0;
547 list_for_each_entry_safe(sgl
, tmp
, &ctx
->tsgl_list
, list
) {
548 struct scatterlist
*sg
= sgl
->sg
;
550 for (i
= 0; i
< sgl
->cur
; i
++) {
554 if (offset
>= sg
[i
].length
) {
555 offset
-= sg
[i
].length
;
556 bytes
-= sg
[i
].length
;
560 bytes_count
= sg
[i
].length
- offset
;
565 /* If we have seen requested number of bytes, stop */
566 if (bytes_count
>= bytes
)
569 bytes
-= bytes_count
;
575 EXPORT_SYMBOL_GPL(af_alg_count_tsgl
);
578 * aead_pull_tsgl - Release the specified buffers from TX SGL
580 * If @dst is non-null, reassign the pages to dst. The caller must release
581 * the pages. If @dst_offset is given only reassign the pages to @dst starting
582 * at the @dst_offset (byte). The caller must ensure that @dst is large
583 * enough (e.g. by using af_alg_count_tsgl with the same offset).
585 * @sk socket of connection to user space
586 * @used Number of bytes to pull from TX SGL
587 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
588 * caller must release the buffers in dst.
589 * @dst_offset Reassign the TX SGL from given offset. All buffers before
590 * reaching the offset is released.
592 void af_alg_pull_tsgl(struct sock
*sk
, size_t used
, struct scatterlist
*dst
,
595 struct alg_sock
*ask
= alg_sk(sk
);
596 struct af_alg_ctx
*ctx
= ask
->private;
597 struct af_alg_tsgl
*sgl
;
598 struct scatterlist
*sg
;
599 unsigned int i
, j
= 0;
601 while (!list_empty(&ctx
->tsgl_list
)) {
602 sgl
= list_first_entry(&ctx
->tsgl_list
, struct af_alg_tsgl
,
606 for (i
= 0; i
< sgl
->cur
; i
++) {
607 size_t plen
= min_t(size_t, used
, sg
[i
].length
);
608 struct page
*page
= sg_page(sg
+ i
);
614 * Assumption: caller created af_alg_count_tsgl(len)
618 if (dst_offset
>= plen
) {
619 /* discard page before offset */
622 /* reassign page to dst after offset */
624 sg_set_page(dst
+ j
, page
,
626 sg
[i
].offset
+ dst_offset
);
632 sg
[i
].length
-= plen
;
633 sg
[i
].offset
+= plen
;
642 sg_assign_page(sg
+ i
, NULL
);
645 list_del(&sgl
->list
);
646 sock_kfree_s(sk
, sgl
, sizeof(*sgl
) + sizeof(sgl
->sg
[0]) *
653 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl
);
656 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
658 * @areq Request holding the TX and RX SGL
660 void af_alg_free_areq_sgls(struct af_alg_async_req
*areq
)
662 struct sock
*sk
= areq
->sk
;
663 struct alg_sock
*ask
= alg_sk(sk
);
664 struct af_alg_ctx
*ctx
= ask
->private;
665 struct af_alg_rsgl
*rsgl
, *tmp
;
666 struct scatterlist
*tsgl
;
667 struct scatterlist
*sg
;
670 list_for_each_entry_safe(rsgl
, tmp
, &areq
->rsgl_list
, list
) {
671 atomic_sub(rsgl
->sg_num_bytes
, &ctx
->rcvused
);
672 af_alg_free_sg(&rsgl
->sgl
);
673 list_del(&rsgl
->list
);
674 if (rsgl
!= &areq
->first_rsgl
)
675 sock_kfree_s(sk
, rsgl
, sizeof(*rsgl
));
680 for_each_sg(tsgl
, sg
, areq
->tsgl_entries
, i
) {
683 put_page(sg_page(sg
));
686 sock_kfree_s(sk
, tsgl
, areq
->tsgl_entries
* sizeof(*tsgl
));
689 EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls
);
692 * af_alg_wait_for_wmem - wait for availability of writable memory
694 * @sk socket of connection to user space
695 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
696 * @return 0 when writable memory is available, < 0 upon error
698 int af_alg_wait_for_wmem(struct sock
*sk
, unsigned int flags
)
700 DEFINE_WAIT_FUNC(wait
, woken_wake_function
);
701 int err
= -ERESTARTSYS
;
704 if (flags
& MSG_DONTWAIT
)
707 sk_set_bit(SOCKWQ_ASYNC_NOSPACE
, sk
);
709 add_wait_queue(sk_sleep(sk
), &wait
);
711 if (signal_pending(current
))
713 timeout
= MAX_SCHEDULE_TIMEOUT
;
714 if (sk_wait_event(sk
, &timeout
, af_alg_writable(sk
), &wait
)) {
719 remove_wait_queue(sk_sleep(sk
), &wait
);
723 EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem
);
726 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
728 * @sk socket of connection to user space
730 void af_alg_wmem_wakeup(struct sock
*sk
)
732 struct socket_wq
*wq
;
734 if (!af_alg_writable(sk
))
738 wq
= rcu_dereference(sk
->sk_wq
);
739 if (skwq_has_sleeper(wq
))
740 wake_up_interruptible_sync_poll(&wq
->wait
, POLLIN
|
743 sk_wake_async(sk
, SOCK_WAKE_WAITD
, POLL_IN
);
746 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup
);
749 * af_alg_wait_for_data - wait for availability of TX data
751 * @sk socket of connection to user space
752 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
753 * @return 0 when writable memory is available, < 0 upon error
755 int af_alg_wait_for_data(struct sock
*sk
, unsigned flags
)
757 DEFINE_WAIT_FUNC(wait
, woken_wake_function
);
758 struct alg_sock
*ask
= alg_sk(sk
);
759 struct af_alg_ctx
*ctx
= ask
->private;
761 int err
= -ERESTARTSYS
;
763 if (flags
& MSG_DONTWAIT
)
766 sk_set_bit(SOCKWQ_ASYNC_WAITDATA
, sk
);
768 add_wait_queue(sk_sleep(sk
), &wait
);
770 if (signal_pending(current
))
772 timeout
= MAX_SCHEDULE_TIMEOUT
;
773 if (sk_wait_event(sk
, &timeout
, (ctx
->used
|| !ctx
->more
),
779 remove_wait_queue(sk_sleep(sk
), &wait
);
781 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA
, sk
);
785 EXPORT_SYMBOL_GPL(af_alg_wait_for_data
);
788 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
790 * @sk socket of connection to user space
793 void af_alg_data_wakeup(struct sock
*sk
)
795 struct alg_sock
*ask
= alg_sk(sk
);
796 struct af_alg_ctx
*ctx
= ask
->private;
797 struct socket_wq
*wq
;
803 wq
= rcu_dereference(sk
->sk_wq
);
804 if (skwq_has_sleeper(wq
))
805 wake_up_interruptible_sync_poll(&wq
->wait
, POLLOUT
|
808 sk_wake_async(sk
, SOCK_WAKE_SPACE
, POLL_OUT
);
811 EXPORT_SYMBOL_GPL(af_alg_data_wakeup
);
814 * af_alg_sendmsg - implementation of sendmsg system call handler
816 * The sendmsg system call handler obtains the user data and stores it
817 * in ctx->tsgl_list. This implies allocation of the required numbers of
818 * struct af_alg_tsgl.
820 * In addition, the ctx is filled with the information sent via CMSG.
822 * @sock socket of connection to user space
823 * @msg message from user space
824 * @size size of message from user space
825 * @ivsize the size of the IV for the cipher operation to verify that the
826 * user-space-provided IV has the right size
827 * @return the number of copied data upon success, < 0 upon error
829 int af_alg_sendmsg(struct socket
*sock
, struct msghdr
*msg
, size_t size
,
832 struct sock
*sk
= sock
->sk
;
833 struct alg_sock
*ask
= alg_sk(sk
);
834 struct af_alg_ctx
*ctx
= ask
->private;
835 struct af_alg_tsgl
*sgl
;
836 struct af_alg_control con
= {};
842 if (msg
->msg_controllen
) {
843 err
= af_alg_cmsg_send(msg
, &con
);
859 if (con
.iv
&& con
.iv
->ivlen
!= ivsize
)
864 if (!ctx
->more
&& ctx
->used
) {
872 memcpy(ctx
->iv
, con
.iv
->iv
, ivsize
);
874 ctx
->aead_assoclen
= con
.aead_assoclen
;
878 struct scatterlist
*sg
;
882 /* use the existing memory in an allocated page */
884 sgl
= list_entry(ctx
->tsgl_list
.prev
,
885 struct af_alg_tsgl
, list
);
886 sg
= sgl
->sg
+ sgl
->cur
- 1;
887 len
= min_t(size_t, len
,
888 PAGE_SIZE
- sg
->offset
- sg
->length
);
890 err
= memcpy_from_msg(page_address(sg_page(sg
)) +
891 sg
->offset
+ sg
->length
,
897 ctx
->merge
= (sg
->offset
+ sg
->length
) &
906 if (!af_alg_writable(sk
)) {
907 err
= af_alg_wait_for_wmem(sk
, msg
->msg_flags
);
912 /* allocate a new page */
913 len
= min_t(unsigned long, len
, af_alg_sndbuf(sk
));
915 err
= af_alg_alloc_tsgl(sk
);
919 sgl
= list_entry(ctx
->tsgl_list
.prev
, struct af_alg_tsgl
,
923 sg_unmark_end(sg
+ sgl
->cur
- 1);
926 unsigned int i
= sgl
->cur
;
928 plen
= min_t(size_t, len
, PAGE_SIZE
);
930 sg_assign_page(sg
+ i
, alloc_page(GFP_KERNEL
));
931 if (!sg_page(sg
+ i
)) {
936 err
= memcpy_from_msg(page_address(sg_page(sg
+ i
)),
939 __free_page(sg_page(sg
+ i
));
940 sg_assign_page(sg
+ i
, NULL
);
950 } while (len
&& sgl
->cur
< MAX_SGL_ENTS
);
953 sg_mark_end(sg
+ sgl
->cur
- 1);
955 ctx
->merge
= plen
& (PAGE_SIZE
- 1);
960 ctx
->more
= msg
->msg_flags
& MSG_MORE
;
963 af_alg_data_wakeup(sk
);
966 return copied
?: err
;
968 EXPORT_SYMBOL_GPL(af_alg_sendmsg
);
971 * af_alg_sendpage - sendpage system call handler
973 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
975 ssize_t
af_alg_sendpage(struct socket
*sock
, struct page
*page
,
976 int offset
, size_t size
, int flags
)
978 struct sock
*sk
= sock
->sk
;
979 struct alg_sock
*ask
= alg_sk(sk
);
980 struct af_alg_ctx
*ctx
= ask
->private;
981 struct af_alg_tsgl
*sgl
;
984 if (flags
& MSG_SENDPAGE_NOTLAST
)
988 if (!ctx
->more
&& ctx
->used
)
994 if (!af_alg_writable(sk
)) {
995 err
= af_alg_wait_for_wmem(sk
, flags
);
1000 err
= af_alg_alloc_tsgl(sk
);
1005 sgl
= list_entry(ctx
->tsgl_list
.prev
, struct af_alg_tsgl
, list
);
1008 sg_unmark_end(sgl
->sg
+ sgl
->cur
- 1);
1010 sg_mark_end(sgl
->sg
+ sgl
->cur
);
1013 sg_set_page(sgl
->sg
+ sgl
->cur
, page
, size
, offset
);
1018 ctx
->more
= flags
& MSG_MORE
;
1021 af_alg_data_wakeup(sk
);
1026 EXPORT_SYMBOL_GPL(af_alg_sendpage
);
1029 * af_alg_free_resources - release resources required for crypto request
1031 void af_alg_free_resources(struct af_alg_async_req
*areq
)
1033 struct sock
*sk
= areq
->sk
;
1035 af_alg_free_areq_sgls(areq
);
1036 sock_kfree_s(sk
, areq
, areq
->areqlen
);
1038 EXPORT_SYMBOL_GPL(af_alg_free_resources
);
1041 * af_alg_async_cb - AIO callback handler
1043 * This handler cleans up the struct af_alg_async_req upon completion of the
1046 * The number of bytes to be generated with the AIO operation must be set
1047 * in areq->outlen before the AIO callback handler is invoked.
1049 void af_alg_async_cb(struct crypto_async_request
*_req
, int err
)
1051 struct af_alg_async_req
*areq
= _req
->data
;
1052 struct sock
*sk
= areq
->sk
;
1053 struct kiocb
*iocb
= areq
->iocb
;
1054 unsigned int resultlen
;
1056 /* Buffer size written by crypto operation. */
1057 resultlen
= areq
->outlen
;
1059 af_alg_free_resources(areq
);
1062 iocb
->ki_complete(iocb
, err
? err
: (int)resultlen
, 0);
1064 EXPORT_SYMBOL_GPL(af_alg_async_cb
);
1067 * af_alg_poll - poll system call handler
1069 unsigned int af_alg_poll(struct file
*file
, struct socket
*sock
,
1072 struct sock
*sk
= sock
->sk
;
1073 struct alg_sock
*ask
= alg_sk(sk
);
1074 struct af_alg_ctx
*ctx
= ask
->private;
1077 sock_poll_wait(file
, sk_sleep(sk
), wait
);
1080 if (!ctx
->more
|| ctx
->used
)
1081 mask
|= POLLIN
| POLLRDNORM
;
1083 if (af_alg_writable(sk
))
1084 mask
|= POLLOUT
| POLLWRNORM
| POLLWRBAND
;
1088 EXPORT_SYMBOL_GPL(af_alg_poll
);
1091 * af_alg_alloc_areq - allocate struct af_alg_async_req
1093 * @sk socket of connection to user space
1094 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1095 * @return allocated data structure or ERR_PTR upon error
1097 struct af_alg_async_req
*af_alg_alloc_areq(struct sock
*sk
,
1098 unsigned int areqlen
)
1100 struct af_alg_async_req
*areq
= sock_kmalloc(sk
, areqlen
, GFP_KERNEL
);
1102 if (unlikely(!areq
))
1103 return ERR_PTR(-ENOMEM
);
1105 areq
->areqlen
= areqlen
;
1107 areq
->last_rsgl
= NULL
;
1108 INIT_LIST_HEAD(&areq
->rsgl_list
);
1110 areq
->tsgl_entries
= 0;
1114 EXPORT_SYMBOL_GPL(af_alg_alloc_areq
);
1117 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1120 * @sk socket of connection to user space
1121 * @msg user space message
1122 * @flags flags used to invoke recvmsg with
1123 * @areq instance of the cryptographic request that will hold the RX SGL
1124 * @maxsize maximum number of bytes to be pulled from user space
1125 * @outlen number of bytes in the RX SGL
1126 * @return 0 on success, < 0 upon error
1128 int af_alg_get_rsgl(struct sock
*sk
, struct msghdr
*msg
, int flags
,
1129 struct af_alg_async_req
*areq
, size_t maxsize
,
1132 struct alg_sock
*ask
= alg_sk(sk
);
1133 struct af_alg_ctx
*ctx
= ask
->private;
1136 while (maxsize
> len
&& msg_data_left(msg
)) {
1137 struct af_alg_rsgl
*rsgl
;
1141 /* limit the amount of readable buffers */
1142 if (!af_alg_readable(sk
))
1145 seglen
= min_t(size_t, (maxsize
- len
),
1146 msg_data_left(msg
));
1148 if (list_empty(&areq
->rsgl_list
)) {
1149 rsgl
= &areq
->first_rsgl
;
1151 rsgl
= sock_kmalloc(sk
, sizeof(*rsgl
), GFP_KERNEL
);
1152 if (unlikely(!rsgl
))
1156 rsgl
->sgl
.npages
= 0;
1157 list_add_tail(&rsgl
->list
, &areq
->rsgl_list
);
1159 /* make one iovec available as scatterlist */
1160 err
= af_alg_make_sg(&rsgl
->sgl
, &msg
->msg_iter
, seglen
);
1162 rsgl
->sg_num_bytes
= 0;
1166 /* chain the new scatterlist with previous one */
1167 if (areq
->last_rsgl
)
1168 af_alg_link_sg(&areq
->last_rsgl
->sgl
, &rsgl
->sgl
);
1170 areq
->last_rsgl
= rsgl
;
1172 atomic_add(err
, &ctx
->rcvused
);
1173 rsgl
->sg_num_bytes
= err
;
1174 iov_iter_advance(&msg
->msg_iter
, err
);
1180 EXPORT_SYMBOL_GPL(af_alg_get_rsgl
);
1182 static int __init
af_alg_init(void)
1184 int err
= proto_register(&alg_proto
, 0);
1189 err
= sock_register(&alg_family
);
1191 goto out_unregister_proto
;
1196 out_unregister_proto
:
1197 proto_unregister(&alg_proto
);
1201 static void __exit
af_alg_exit(void)
1203 sock_unregister(PF_ALG
);
1204 proto_unregister(&alg_proto
);
1207 module_init(af_alg_init
);
1208 module_exit(af_alg_exit
);
1209 MODULE_LICENSE("GPL");
1210 MODULE_ALIAS_NETPROTO(AF_ALG
);