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 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
536 struct page **pages = sgl->pages;
541 n = iov_iter_extract_pages(iter, &pages, len, ALG_MAX_PAGES, 0, &off);
545 sgl->need_unpin = iov_iter_extract_will_pin(iter);
547 npages = DIV_ROUND_UP(off + n, PAGE_SIZE);
548 if (WARN_ON(npages == 0))
550 /* Add one extra for linking */
551 sg_init_table(sgl->sg, npages + 1);
553 for (i = 0, len = n; i < npages; i++) {
554 int plen = min_t(int, len, PAGE_SIZE - off);
556 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
561 sg_mark_end(sgl->sg + npages - 1);
562 sgl->npages = npages;
566 EXPORT_SYMBOL_GPL(af_alg_make_sg);
568 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
569 struct af_alg_sgl *sgl_new)
571 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
572 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
575 void af_alg_free_sg(struct af_alg_sgl *sgl)
580 for (i = 0; i < sgl->npages; i++)
581 unpin_user_page(sgl->pages[i]);
583 EXPORT_SYMBOL_GPL(af_alg_free_sg);
585 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
587 struct cmsghdr *cmsg;
589 for_each_cmsghdr(cmsg, msg) {
590 if (!CMSG_OK(msg, cmsg))
592 if (cmsg->cmsg_level != SOL_ALG)
595 switch (cmsg->cmsg_type) {
597 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
599 con->iv = (void *)CMSG_DATA(cmsg);
600 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
606 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
608 con->op = *(u32 *)CMSG_DATA(cmsg);
611 case ALG_SET_AEAD_ASSOCLEN:
612 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
614 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
626 * af_alg_alloc_tsgl - allocate the TX SGL
628 * @sk: socket of connection to user space
629 * Return: 0 upon success, < 0 upon error
631 static int af_alg_alloc_tsgl(struct sock *sk)
633 struct alg_sock *ask = alg_sk(sk);
634 struct af_alg_ctx *ctx = ask->private;
635 struct af_alg_tsgl *sgl;
636 struct scatterlist *sg = NULL;
638 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
639 if (!list_empty(&ctx->tsgl_list))
642 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
643 sgl = sock_kmalloc(sk,
644 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
649 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
653 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
655 list_add_tail(&sgl->list, &ctx->tsgl_list);
662 * af_alg_count_tsgl - Count number of TX SG entries
664 * The counting starts from the beginning of the SGL to @bytes. If
665 * an @offset is provided, the counting of the SG entries starts at the @offset.
667 * @sk: socket of connection to user space
668 * @bytes: Count the number of SG entries holding given number of bytes.
669 * @offset: Start the counting of SG entries from the given offset.
670 * Return: Number of TX SG entries found given the constraints
672 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
674 const struct alg_sock *ask = alg_sk(sk);
675 const struct af_alg_ctx *ctx = ask->private;
676 const struct af_alg_tsgl *sgl;
678 unsigned int sgl_count = 0;
683 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
684 const struct scatterlist *sg = sgl->sg;
686 for (i = 0; i < sgl->cur; i++) {
690 if (offset >= sg[i].length) {
691 offset -= sg[i].length;
692 bytes -= sg[i].length;
696 bytes_count = sg[i].length - offset;
701 /* If we have seen requested number of bytes, stop */
702 if (bytes_count >= bytes)
705 bytes -= bytes_count;
711 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
714 * af_alg_pull_tsgl - Release the specified buffers from TX SGL
716 * If @dst is non-null, reassign the pages to @dst. The caller must release
717 * the pages. If @dst_offset is given only reassign the pages to @dst starting
718 * at the @dst_offset (byte). The caller must ensure that @dst is large
719 * enough (e.g. by using af_alg_count_tsgl with the same offset).
721 * @sk: socket of connection to user space
722 * @used: Number of bytes to pull from TX SGL
723 * @dst: If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
724 * caller must release the buffers in dst.
725 * @dst_offset: Reassign the TX SGL from given offset. All buffers before
726 * reaching the offset is released.
728 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
731 struct alg_sock *ask = alg_sk(sk);
732 struct af_alg_ctx *ctx = ask->private;
733 struct af_alg_tsgl *sgl;
734 struct scatterlist *sg;
735 unsigned int i, j = 0;
737 while (!list_empty(&ctx->tsgl_list)) {
738 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
742 for (i = 0; i < sgl->cur; i++) {
743 size_t plen = min_t(size_t, used, sg[i].length);
744 struct page *page = sg_page(sg + i);
750 * Assumption: caller created af_alg_count_tsgl(len)
754 if (dst_offset >= plen) {
755 /* discard page before offset */
758 /* reassign page to dst after offset */
760 sg_set_page(dst + j, page,
762 sg[i].offset + dst_offset);
768 sg[i].length -= plen;
769 sg[i].offset += plen;
778 sg_assign_page(sg + i, NULL);
781 list_del(&sgl->list);
782 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
787 ctx->init = ctx->more;
789 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
792 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
794 * @areq: Request holding the TX and RX SGL
796 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
798 struct sock *sk = areq->sk;
799 struct alg_sock *ask = alg_sk(sk);
800 struct af_alg_ctx *ctx = ask->private;
801 struct af_alg_rsgl *rsgl, *tmp;
802 struct scatterlist *tsgl;
803 struct scatterlist *sg;
806 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
807 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
808 af_alg_free_sg(&rsgl->sgl);
809 list_del(&rsgl->list);
810 if (rsgl != &areq->first_rsgl)
811 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
816 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
819 put_page(sg_page(sg));
822 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
827 * af_alg_wait_for_wmem - wait for availability of writable memory
829 * @sk: socket of connection to user space
830 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep
831 * Return: 0 when writable memory is available, < 0 upon error
833 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
835 DEFINE_WAIT_FUNC(wait, woken_wake_function);
836 int err = -ERESTARTSYS;
839 if (flags & MSG_DONTWAIT)
842 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
844 add_wait_queue(sk_sleep(sk), &wait);
846 if (signal_pending(current))
848 timeout = MAX_SCHEDULE_TIMEOUT;
849 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
854 remove_wait_queue(sk_sleep(sk), &wait);
860 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
862 * @sk: socket of connection to user space
864 void af_alg_wmem_wakeup(struct sock *sk)
866 struct socket_wq *wq;
868 if (!af_alg_writable(sk))
872 wq = rcu_dereference(sk->sk_wq);
873 if (skwq_has_sleeper(wq))
874 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
877 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
880 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
883 * af_alg_wait_for_data - wait for availability of TX data
885 * @sk: socket of connection to user space
886 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep
887 * @min: Set to minimum request size if partial requests are allowed.
888 * Return: 0 when writable memory is available, < 0 upon error
890 int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min)
892 DEFINE_WAIT_FUNC(wait, woken_wake_function);
893 struct alg_sock *ask = alg_sk(sk);
894 struct af_alg_ctx *ctx = ask->private;
896 int err = -ERESTARTSYS;
898 if (flags & MSG_DONTWAIT)
901 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
903 add_wait_queue(sk_sleep(sk), &wait);
905 if (signal_pending(current))
907 timeout = MAX_SCHEDULE_TIMEOUT;
908 if (sk_wait_event(sk, &timeout,
909 ctx->init && (!ctx->more ||
910 (min && ctx->used >= min)),
916 remove_wait_queue(sk_sleep(sk), &wait);
918 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
922 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
925 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
927 * @sk: socket of connection to user space
929 static void af_alg_data_wakeup(struct sock *sk)
931 struct alg_sock *ask = alg_sk(sk);
932 struct af_alg_ctx *ctx = ask->private;
933 struct socket_wq *wq;
939 wq = rcu_dereference(sk->sk_wq);
940 if (skwq_has_sleeper(wq))
941 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
944 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
949 * af_alg_sendmsg - implementation of sendmsg system call handler
951 * The sendmsg system call handler obtains the user data and stores it
952 * in ctx->tsgl_list. This implies allocation of the required numbers of
953 * struct af_alg_tsgl.
955 * In addition, the ctx is filled with the information sent via CMSG.
957 * @sock: socket of connection to user space
958 * @msg: message from user space
959 * @size: size of message from user space
960 * @ivsize: the size of the IV for the cipher operation to verify that the
961 * user-space-provided IV has the right size
962 * Return: the number of copied data upon success, < 0 upon error
964 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
967 struct sock *sk = sock->sk;
968 struct alg_sock *ask = alg_sk(sk);
969 struct af_alg_ctx *ctx = ask->private;
970 struct af_alg_tsgl *sgl;
971 struct af_alg_control con = {};
977 if (msg->msg_controllen) {
978 err = af_alg_cmsg_send(msg, &con);
994 if (con.iv && con.iv->ivlen != ivsize)
999 if (ctx->init && !ctx->more) {
1006 "%s sent an empty control message without MSG_MORE.\n",
1014 memcpy(ctx->iv, con.iv->iv, ivsize);
1016 ctx->aead_assoclen = con.aead_assoclen;
1020 struct scatterlist *sg;
1024 /* use the existing memory in an allocated page */
1026 sgl = list_entry(ctx->tsgl_list.prev,
1027 struct af_alg_tsgl, list);
1028 sg = sgl->sg + sgl->cur - 1;
1029 len = min_t(size_t, len,
1030 PAGE_SIZE - sg->offset - sg->length);
1032 err = memcpy_from_msg(page_address(sg_page(sg)) +
1033 sg->offset + sg->length,
1039 ctx->merge = (sg->offset + sg->length) &
1048 if (!af_alg_writable(sk)) {
1049 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
1054 /* allocate a new page */
1055 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
1057 err = af_alg_alloc_tsgl(sk);
1061 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
1065 sg_unmark_end(sg + sgl->cur - 1);
1069 unsigned int i = sgl->cur;
1071 plen = min_t(size_t, len, PAGE_SIZE);
1073 pg = alloc_page(GFP_KERNEL);
1079 sg_assign_page(sg + i, pg);
1081 err = memcpy_from_msg(page_address(sg_page(sg + i)),
1084 __free_page(sg_page(sg + i));
1085 sg_assign_page(sg + i, NULL);
1089 sg[i].length = plen;
1095 } while (len && sgl->cur < MAX_SGL_ENTS);
1098 sg_mark_end(sg + sgl->cur - 1);
1100 ctx->merge = plen & (PAGE_SIZE - 1);
1105 ctx->more = msg->msg_flags & MSG_MORE;
1108 af_alg_data_wakeup(sk);
1111 return copied ?: err;
1113 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
1116 * af_alg_sendpage - sendpage system call handler
1117 * @sock: socket of connection to user space to write to
1118 * @page: data to send
1119 * @offset: offset into page to begin sending
1120 * @size: length of data
1121 * @flags: message send/receive flags
1123 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
1125 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
1126 int offset, size_t size, int flags)
1128 struct sock *sk = sock->sk;
1129 struct alg_sock *ask = alg_sk(sk);
1130 struct af_alg_ctx *ctx = ask->private;
1131 struct af_alg_tsgl *sgl;
1134 if (flags & MSG_SENDPAGE_NOTLAST)
1138 if (!ctx->more && ctx->used)
1144 if (!af_alg_writable(sk)) {
1145 err = af_alg_wait_for_wmem(sk, flags);
1150 err = af_alg_alloc_tsgl(sk);
1155 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1158 sg_unmark_end(sgl->sg + sgl->cur - 1);
1160 sg_mark_end(sgl->sg + sgl->cur);
1163 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1168 ctx->more = flags & MSG_MORE;
1171 af_alg_data_wakeup(sk);
1176 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1179 * af_alg_free_resources - release resources required for crypto request
1180 * @areq: Request holding the TX and RX SGL
1182 void af_alg_free_resources(struct af_alg_async_req *areq)
1184 struct sock *sk = areq->sk;
1186 af_alg_free_areq_sgls(areq);
1187 sock_kfree_s(sk, areq, areq->areqlen);
1189 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1192 * af_alg_async_cb - AIO callback handler
1193 * @data: async request completion data
1194 * @err: if non-zero, error result to be returned via ki_complete();
1195 * otherwise return the AIO output length via ki_complete().
1197 * This handler cleans up the struct af_alg_async_req upon completion of the
1200 * The number of bytes to be generated with the AIO operation must be set
1201 * in areq->outlen before the AIO callback handler is invoked.
1203 void af_alg_async_cb(void *data, int err)
1205 struct af_alg_async_req *areq = data;
1206 struct sock *sk = areq->sk;
1207 struct kiocb *iocb = areq->iocb;
1208 unsigned int resultlen;
1210 /* Buffer size written by crypto operation. */
1211 resultlen = areq->outlen;
1213 af_alg_free_resources(areq);
1216 iocb->ki_complete(iocb, err ? err : (int)resultlen);
1218 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1221 * af_alg_poll - poll system call handler
1222 * @file: file pointer
1223 * @sock: socket to poll
1226 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1229 struct sock *sk = sock->sk;
1230 struct alg_sock *ask = alg_sk(sk);
1231 struct af_alg_ctx *ctx = ask->private;
1234 sock_poll_wait(file, sock, wait);
1237 if (!ctx->more || ctx->used)
1238 mask |= EPOLLIN | EPOLLRDNORM;
1240 if (af_alg_writable(sk))
1241 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1245 EXPORT_SYMBOL_GPL(af_alg_poll);
1248 * af_alg_alloc_areq - allocate struct af_alg_async_req
1250 * @sk: socket of connection to user space
1251 * @areqlen: size of struct af_alg_async_req + crypto_*_reqsize
1252 * Return: allocated data structure or ERR_PTR upon error
1254 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1255 unsigned int areqlen)
1257 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1259 if (unlikely(!areq))
1260 return ERR_PTR(-ENOMEM);
1262 areq->areqlen = areqlen;
1264 areq->last_rsgl = NULL;
1265 INIT_LIST_HEAD(&areq->rsgl_list);
1267 areq->tsgl_entries = 0;
1271 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1274 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1277 * @sk: socket of connection to user space
1278 * @msg: user space message
1279 * @flags: flags used to invoke recvmsg with
1280 * @areq: instance of the cryptographic request that will hold the RX SGL
1281 * @maxsize: maximum number of bytes to be pulled from user space
1282 * @outlen: number of bytes in the RX SGL
1283 * Return: 0 on success, < 0 upon error
1285 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1286 struct af_alg_async_req *areq, size_t maxsize,
1289 struct alg_sock *ask = alg_sk(sk);
1290 struct af_alg_ctx *ctx = ask->private;
1293 while (maxsize > len && msg_data_left(msg)) {
1294 struct af_alg_rsgl *rsgl;
1298 /* limit the amount of readable buffers */
1299 if (!af_alg_readable(sk))
1302 seglen = min_t(size_t, (maxsize - len),
1303 msg_data_left(msg));
1305 if (list_empty(&areq->rsgl_list)) {
1306 rsgl = &areq->first_rsgl;
1308 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1309 if (unlikely(!rsgl))
1313 rsgl->sgl.npages = 0;
1314 list_add_tail(&rsgl->list, &areq->rsgl_list);
1316 /* make one iovec available as scatterlist */
1317 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1319 rsgl->sg_num_bytes = 0;
1323 /* chain the new scatterlist with previous one */
1324 if (areq->last_rsgl)
1325 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1327 areq->last_rsgl = rsgl;
1329 atomic_add(err, &ctx->rcvused);
1330 rsgl->sg_num_bytes = err;
1336 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1338 static int __init af_alg_init(void)
1340 int err = proto_register(&alg_proto, 0);
1345 err = sock_register(&alg_family);
1347 goto out_unregister_proto;
1352 out_unregister_proto:
1353 proto_unregister(&alg_proto);
1357 static void __exit af_alg_exit(void)
1359 sock_unregister(PF_ALG);
1360 proto_unregister(&alg_proto);
1363 module_init(af_alg_init);
1364 module_exit(af_alg_exit);
1365 MODULE_LICENSE("GPL");
1366 MODULE_ALIAS_NETPROTO(AF_ALG);