diff options
Diffstat (limited to '')
| -rw-r--r-- | crypto/af_alg.c | 1230 |
1 files changed, 1230 insertions, 0 deletions
diff --git a/crypto/af_alg.c b/crypto/af_alg.c new file mode 100644 index 000000000..755e6caf1 --- /dev/null +++ b/crypto/af_alg.c @@ -0,0 +1,1230 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * af_alg: User-space algorithm interface + * + * This file provides the user-space API for algorithms. + * + * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au> + */ + +#include <linux/atomic.h> +#include <crypto/if_alg.h> +#include <linux/crypto.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/net.h> +#include <linux/rwsem.h> +#include <linux/sched.h> +#include <linux/sched/signal.h> +#include <linux/security.h> + +struct alg_type_list { + const struct af_alg_type *type; + struct list_head list; +}; + +static atomic_long_t alg_memory_allocated; + +static struct proto alg_proto = { + .name = "ALG", + .owner = THIS_MODULE, + .memory_allocated = &alg_memory_allocated, + .obj_size = sizeof(struct alg_sock), +}; + +static LIST_HEAD(alg_types); +static DECLARE_RWSEM(alg_types_sem); + +static const struct af_alg_type *alg_get_type(const char *name) +{ + const struct af_alg_type *type = ERR_PTR(-ENOENT); + struct alg_type_list *node; + + down_read(&alg_types_sem); + list_for_each_entry(node, &alg_types, list) { + if (strcmp(node->type->name, name)) + continue; + + if (try_module_get(node->type->owner)) + type = node->type; + break; + } + up_read(&alg_types_sem); + + return type; +} + +int af_alg_register_type(const struct af_alg_type *type) +{ + struct alg_type_list *node; + int err = -EEXIST; + + down_write(&alg_types_sem); + list_for_each_entry(node, &alg_types, list) { + if (!strcmp(node->type->name, type->name)) + goto unlock; + } + + node = kmalloc(sizeof(*node), GFP_KERNEL); + err = -ENOMEM; + if (!node) + goto unlock; + + type->ops->owner = THIS_MODULE; + if (type->ops_nokey) + type->ops_nokey->owner = THIS_MODULE; + node->type = type; + list_add(&node->list, &alg_types); + err = 0; + +unlock: + up_write(&alg_types_sem); + + return err; +} +EXPORT_SYMBOL_GPL(af_alg_register_type); + +int af_alg_unregister_type(const struct af_alg_type *type) +{ + struct alg_type_list *node; + int err = -ENOENT; + + down_write(&alg_types_sem); + list_for_each_entry(node, &alg_types, list) { + if (strcmp(node->type->name, type->name)) + continue; + + list_del(&node->list); + kfree(node); + err = 0; + break; + } + up_write(&alg_types_sem); + + return err; +} +EXPORT_SYMBOL_GPL(af_alg_unregister_type); + +static void alg_do_release(const struct af_alg_type *type, void *private) +{ + if (!type) + return; + + type->release(private); + module_put(type->owner); +} + +int af_alg_release(struct socket *sock) +{ + if (sock->sk) { + sock_put(sock->sk); + sock->sk = NULL; + } + return 0; +} +EXPORT_SYMBOL_GPL(af_alg_release); + +void af_alg_release_parent(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + unsigned int nokey = atomic_read(&ask->nokey_refcnt); + + sk = ask->parent; + ask = alg_sk(sk); + + if (nokey) + atomic_dec(&ask->nokey_refcnt); + + if (atomic_dec_and_test(&ask->refcnt)) + sock_put(sk); +} +EXPORT_SYMBOL_GPL(af_alg_release_parent); + +static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) +{ + const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY; + struct sock *sk = sock->sk; + struct alg_sock *ask = alg_sk(sk); + struct sockaddr_alg_new *sa = (void *)uaddr; + const struct af_alg_type *type; + void *private; + int err; + + if (sock->state == SS_CONNECTED) + return -EINVAL; + + BUILD_BUG_ON(offsetof(struct sockaddr_alg_new, salg_name) != + offsetof(struct sockaddr_alg, salg_name)); + BUILD_BUG_ON(offsetof(struct sockaddr_alg, salg_name) != sizeof(*sa)); + + if (addr_len < sizeof(*sa) + 1) + return -EINVAL; + + /* If caller uses non-allowed flag, return error. */ + if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed)) + return -EINVAL; + + sa->salg_type[sizeof(sa->salg_type) - 1] = 0; + sa->salg_name[addr_len - sizeof(*sa) - 1] = 0; + + type = alg_get_type(sa->salg_type); + if (PTR_ERR(type) == -ENOENT) { + request_module("algif-%s", sa->salg_type); + type = alg_get_type(sa->salg_type); + } + + if (IS_ERR(type)) + return PTR_ERR(type); + + private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask); + if (IS_ERR(private)) { + module_put(type->owner); + return PTR_ERR(private); + } + + err = -EBUSY; + lock_sock(sk); + if (atomic_read(&ask->refcnt)) + goto unlock; + + swap(ask->type, type); + swap(ask->private, private); + + err = 0; + +unlock: + release_sock(sk); + + alg_do_release(type, private); + + return err; +} + +static int alg_setkey(struct sock *sk, sockptr_t ukey, unsigned int keylen) +{ + struct alg_sock *ask = alg_sk(sk); + const struct af_alg_type *type = ask->type; + u8 *key; + int err; + + key = sock_kmalloc(sk, keylen, GFP_KERNEL); + if (!key) + return -ENOMEM; + + err = -EFAULT; + if (copy_from_sockptr(key, ukey, keylen)) + goto out; + + err = type->setkey(ask->private, key, keylen); + +out: + sock_kzfree_s(sk, key, keylen); + + return err; +} + +static int alg_setsockopt(struct socket *sock, int level, int optname, + sockptr_t optval, unsigned int optlen) +{ + struct sock *sk = sock->sk; + struct alg_sock *ask = alg_sk(sk); + const struct af_alg_type *type; + int err = -EBUSY; + + lock_sock(sk); + if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt)) + goto unlock; + + type = ask->type; + + err = -ENOPROTOOPT; + if (level != SOL_ALG || !type) + goto unlock; + + switch (optname) { + case ALG_SET_KEY: + if (sock->state == SS_CONNECTED) + goto unlock; + if (!type->setkey) + goto unlock; + + err = alg_setkey(sk, optval, optlen); + break; + case ALG_SET_AEAD_AUTHSIZE: + if (sock->state == SS_CONNECTED) + goto unlock; + if (!type->setauthsize) + goto unlock; + err = type->setauthsize(ask->private, optlen); + break; + case ALG_SET_DRBG_ENTROPY: + if (sock->state == SS_CONNECTED) + goto unlock; + if (!type->setentropy) + goto unlock; + + err = type->setentropy(ask->private, optval, optlen); + } + +unlock: + release_sock(sk); + + return err; +} + +int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern) +{ + struct alg_sock *ask = alg_sk(sk); + const struct af_alg_type *type; + struct sock *sk2; + unsigned int nokey; + int err; + + lock_sock(sk); + type = ask->type; + + err = -EINVAL; + if (!type) + goto unlock; + + sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern); + err = -ENOMEM; + if (!sk2) + goto unlock; + + sock_init_data(newsock, sk2); + security_sock_graft(sk2, newsock); + security_sk_clone(sk, sk2); + + /* + * newsock->ops assigned here to allow type->accept call to override + * them when required. + */ + newsock->ops = type->ops; + err = type->accept(ask->private, sk2); + + nokey = err == -ENOKEY; + if (nokey && type->accept_nokey) + err = type->accept_nokey(ask->private, sk2); + + if (err) + goto unlock; + + if (atomic_inc_return_relaxed(&ask->refcnt) == 1) + sock_hold(sk); + if (nokey) { + atomic_inc(&ask->nokey_refcnt); + atomic_set(&alg_sk(sk2)->nokey_refcnt, 1); + } + alg_sk(sk2)->parent = sk; + alg_sk(sk2)->type = type; + + newsock->state = SS_CONNECTED; + + if (nokey) + newsock->ops = type->ops_nokey; + + err = 0; + +unlock: + release_sock(sk); + + return err; +} +EXPORT_SYMBOL_GPL(af_alg_accept); + +static int alg_accept(struct socket *sock, struct socket *newsock, int flags, + bool kern) +{ + return af_alg_accept(sock->sk, newsock, kern); +} + +static const struct proto_ops alg_proto_ops = { + .family = PF_ALG, + .owner = THIS_MODULE, + + .connect = sock_no_connect, + .socketpair = sock_no_socketpair, + .getname = sock_no_getname, + .ioctl = sock_no_ioctl, + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, + .sendmsg = sock_no_sendmsg, + .recvmsg = sock_no_recvmsg, + + .bind = alg_bind, + .release = af_alg_release, + .setsockopt = alg_setsockopt, + .accept = alg_accept, +}; + +static void alg_sock_destruct(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + + alg_do_release(ask->type, ask->private); +} + +static int alg_create(struct net *net, struct socket *sock, int protocol, + int kern) +{ + struct sock *sk; + int err; + + if (sock->type != SOCK_SEQPACKET) + return -ESOCKTNOSUPPORT; + if (protocol != 0) + return -EPROTONOSUPPORT; + + err = -ENOMEM; + sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern); + if (!sk) + goto out; + + sock->ops = &alg_proto_ops; + sock_init_data(sock, sk); + + sk->sk_destruct = alg_sock_destruct; + + return 0; +out: + return err; +} + +static const struct net_proto_family alg_family = { + .family = PF_ALG, + .create = alg_create, + .owner = THIS_MODULE, +}; + +int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len) +{ + size_t off; + ssize_t n; + int npages, i; + + n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off); + if (n < 0) + return n; + + npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT; + if (WARN_ON(npages == 0)) + return -EINVAL; + /* Add one extra for linking */ + sg_init_table(sgl->sg, npages + 1); + + for (i = 0, len = n; i < npages; i++) { + int plen = min_t(int, len, PAGE_SIZE - off); + + sg_set_page(sgl->sg + i, sgl->pages[i], plen, off); + + off = 0; + len -= plen; + } + sg_mark_end(sgl->sg + npages - 1); + sgl->npages = npages; + + return n; +} +EXPORT_SYMBOL_GPL(af_alg_make_sg); + +static void af_alg_link_sg(struct af_alg_sgl *sgl_prev, + struct af_alg_sgl *sgl_new) +{ + sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1); + sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg); +} + +void af_alg_free_sg(struct af_alg_sgl *sgl) +{ + int i; + + for (i = 0; i < sgl->npages; i++) + put_page(sgl->pages[i]); +} +EXPORT_SYMBOL_GPL(af_alg_free_sg); + +static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con) +{ + struct cmsghdr *cmsg; + + for_each_cmsghdr(cmsg, msg) { + if (!CMSG_OK(msg, cmsg)) + return -EINVAL; + if (cmsg->cmsg_level != SOL_ALG) + continue; + + switch (cmsg->cmsg_type) { + case ALG_SET_IV: + if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv))) + return -EINVAL; + con->iv = (void *)CMSG_DATA(cmsg); + if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen + + sizeof(*con->iv))) + return -EINVAL; + break; + + case ALG_SET_OP: + if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) + return -EINVAL; + con->op = *(u32 *)CMSG_DATA(cmsg); + break; + + case ALG_SET_AEAD_ASSOCLEN: + if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) + return -EINVAL; + con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg); + break; + + default: + return -EINVAL; + } + } + + return 0; +} + +/** + * af_alg_alloc_tsgl - allocate the TX SGL + * + * @sk socket of connection to user space + * @return: 0 upon success, < 0 upon error + */ +static int af_alg_alloc_tsgl(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + struct af_alg_ctx *ctx = ask->private; + struct af_alg_tsgl *sgl; + struct scatterlist *sg = NULL; + + sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list); + if (!list_empty(&ctx->tsgl_list)) + sg = sgl->sg; + + if (!sg || sgl->cur >= MAX_SGL_ENTS) { + sgl = sock_kmalloc(sk, + struct_size(sgl, sg, (MAX_SGL_ENTS + 1)), + GFP_KERNEL); + if (!sgl) + return -ENOMEM; + + sg_init_table(sgl->sg, MAX_SGL_ENTS + 1); + sgl->cur = 0; + + if (sg) + sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg); + + list_add_tail(&sgl->list, &ctx->tsgl_list); + } + + return 0; +} + +/** + * aead_count_tsgl - Count number of TX SG entries + * + * The counting starts from the beginning of the SGL to @bytes. If + * an offset is provided, the counting of the SG entries starts at the offset. + * + * @sk socket of connection to user space + * @bytes Count the number of SG entries holding given number of bytes. + * @offset Start the counting of SG entries from the given offset. + * @return Number of TX SG entries found given the constraints + */ +unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset) +{ + const struct alg_sock *ask = alg_sk(sk); + const struct af_alg_ctx *ctx = ask->private; + const struct af_alg_tsgl *sgl; + unsigned int i; + unsigned int sgl_count = 0; + + if (!bytes) + return 0; + + list_for_each_entry(sgl, &ctx->tsgl_list, list) { + const struct scatterlist *sg = sgl->sg; + + for (i = 0; i < sgl->cur; i++) { + size_t bytes_count; + + /* Skip offset */ + if (offset >= sg[i].length) { + offset -= sg[i].length; + bytes -= sg[i].length; + continue; + } + + bytes_count = sg[i].length - offset; + + offset = 0; + sgl_count++; + + /* If we have seen requested number of bytes, stop */ + if (bytes_count >= bytes) + return sgl_count; + + bytes -= bytes_count; + } + } + + return sgl_count; +} +EXPORT_SYMBOL_GPL(af_alg_count_tsgl); + +/** + * aead_pull_tsgl - Release the specified buffers from TX SGL + * + * If @dst is non-null, reassign the pages to dst. The caller must release + * the pages. If @dst_offset is given only reassign the pages to @dst starting + * at the @dst_offset (byte). The caller must ensure that @dst is large + * enough (e.g. by using af_alg_count_tsgl with the same offset). + * + * @sk socket of connection to user space + * @used Number of bytes to pull from TX SGL + * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The + * caller must release the buffers in dst. + * @dst_offset Reassign the TX SGL from given offset. All buffers before + * reaching the offset is released. + */ +void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst, + size_t dst_offset) +{ + struct alg_sock *ask = alg_sk(sk); + struct af_alg_ctx *ctx = ask->private; + struct af_alg_tsgl *sgl; + struct scatterlist *sg; + unsigned int i, j = 0; + + while (!list_empty(&ctx->tsgl_list)) { + sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl, + list); + sg = sgl->sg; + + for (i = 0; i < sgl->cur; i++) { + size_t plen = min_t(size_t, used, sg[i].length); + struct page *page = sg_page(sg + i); + + if (!page) + continue; + + /* + * Assumption: caller created af_alg_count_tsgl(len) + * SG entries in dst. + */ + if (dst) { + if (dst_offset >= plen) { + /* discard page before offset */ + dst_offset -= plen; + } else { + /* reassign page to dst after offset */ + get_page(page); + sg_set_page(dst + j, page, + plen - dst_offset, + sg[i].offset + dst_offset); + dst_offset = 0; + j++; + } + } + + sg[i].length -= plen; + sg[i].offset += plen; + + used -= plen; + ctx->used -= plen; + + if (sg[i].length) + return; + + put_page(page); + sg_assign_page(sg + i, NULL); + } + + list_del(&sgl->list); + sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1)); + } + + if (!ctx->used) + ctx->merge = 0; + ctx->init = ctx->more; +} +EXPORT_SYMBOL_GPL(af_alg_pull_tsgl); + +/** + * af_alg_free_areq_sgls - Release TX and RX SGLs of the request + * + * @areq Request holding the TX and RX SGL + */ +static void af_alg_free_areq_sgls(struct af_alg_async_req *areq) +{ + struct sock *sk = areq->sk; + struct alg_sock *ask = alg_sk(sk); + struct af_alg_ctx *ctx = ask->private; + struct af_alg_rsgl *rsgl, *tmp; + struct scatterlist *tsgl; + struct scatterlist *sg; + unsigned int i; + + list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) { + atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused); + af_alg_free_sg(&rsgl->sgl); + list_del(&rsgl->list); + if (rsgl != &areq->first_rsgl) + sock_kfree_s(sk, rsgl, sizeof(*rsgl)); + } + + tsgl = areq->tsgl; + if (tsgl) { + for_each_sg(tsgl, sg, areq->tsgl_entries, i) { + if (!sg_page(sg)) + continue; + put_page(sg_page(sg)); + } + + sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl)); + } +} + +/** + * af_alg_wait_for_wmem - wait for availability of writable memory + * + * @sk socket of connection to user space + * @flags If MSG_DONTWAIT is set, then only report if function would sleep + * @return 0 when writable memory is available, < 0 upon error + */ +static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags) +{ + DEFINE_WAIT_FUNC(wait, woken_wake_function); + int err = -ERESTARTSYS; + long timeout; + + if (flags & MSG_DONTWAIT) + return -EAGAIN; + + sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); + + add_wait_queue(sk_sleep(sk), &wait); + for (;;) { + if (signal_pending(current)) + break; + timeout = MAX_SCHEDULE_TIMEOUT; + if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) { + err = 0; + break; + } + } + remove_wait_queue(sk_sleep(sk), &wait); + + return err; +} + +/** + * af_alg_wmem_wakeup - wakeup caller when writable memory is available + * + * @sk socket of connection to user space + */ +void af_alg_wmem_wakeup(struct sock *sk) +{ + struct socket_wq *wq; + + if (!af_alg_writable(sk)) + return; + + rcu_read_lock(); + wq = rcu_dereference(sk->sk_wq); + if (skwq_has_sleeper(wq)) + wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | + EPOLLRDNORM | + EPOLLRDBAND); + sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup); + +/** + * af_alg_wait_for_data - wait for availability of TX data + * + * @sk socket of connection to user space + * @flags If MSG_DONTWAIT is set, then only report if function would sleep + * @min Set to minimum request size if partial requests are allowed. + * @return 0 when writable memory is available, < 0 upon error + */ +int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min) +{ + DEFINE_WAIT_FUNC(wait, woken_wake_function); + struct alg_sock *ask = alg_sk(sk); + struct af_alg_ctx *ctx = ask->private; + long timeout; + int err = -ERESTARTSYS; + + if (flags & MSG_DONTWAIT) + return -EAGAIN; + + sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); + + add_wait_queue(sk_sleep(sk), &wait); + for (;;) { + if (signal_pending(current)) + break; + timeout = MAX_SCHEDULE_TIMEOUT; + if (sk_wait_event(sk, &timeout, + ctx->init && (!ctx->more || + (min && ctx->used >= min)), + &wait)) { + err = 0; + break; + } + } + remove_wait_queue(sk_sleep(sk), &wait); + + sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); + + return err; +} +EXPORT_SYMBOL_GPL(af_alg_wait_for_data); + +/** + * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel + * + * @sk socket of connection to user space + */ +static void af_alg_data_wakeup(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + struct af_alg_ctx *ctx = ask->private; + struct socket_wq *wq; + + if (!ctx->used) + return; + + rcu_read_lock(); + wq = rcu_dereference(sk->sk_wq); + if (skwq_has_sleeper(wq)) + wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT | + EPOLLRDNORM | + EPOLLRDBAND); + sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); + rcu_read_unlock(); +} + +/** + * af_alg_sendmsg - implementation of sendmsg system call handler + * + * The sendmsg system call handler obtains the user data and stores it + * in ctx->tsgl_list. This implies allocation of the required numbers of + * struct af_alg_tsgl. + * + * In addition, the ctx is filled with the information sent via CMSG. + * + * @sock socket of connection to user space + * @msg message from user space + * @size size of message from user space + * @ivsize the size of the IV for the cipher operation to verify that the + * user-space-provided IV has the right size + * @return the number of copied data upon success, < 0 upon error + */ +int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, + unsigned int ivsize) +{ + struct sock *sk = sock->sk; + struct alg_sock *ask = alg_sk(sk); + struct af_alg_ctx *ctx = ask->private; + struct af_alg_tsgl *sgl; + struct af_alg_control con = {}; + long copied = 0; + bool enc = false; + bool init = false; + int err = 0; + + if (msg->msg_controllen) { + err = af_alg_cmsg_send(msg, &con); + if (err) + return err; + + init = true; + switch (con.op) { + case ALG_OP_ENCRYPT: + enc = true; + break; + case ALG_OP_DECRYPT: + enc = false; + break; + default: + return -EINVAL; + } + + if (con.iv && con.iv->ivlen != ivsize) + return -EINVAL; + } + + lock_sock(sk); + if (ctx->init && !ctx->more) { + if (ctx->used) { + err = -EINVAL; + goto unlock; + } + + pr_info_once( + "%s sent an empty control message without MSG_MORE.\n", + current->comm); + } + ctx->init = true; + + if (init) { + ctx->enc = enc; + if (con.iv) + memcpy(ctx->iv, con.iv->iv, ivsize); + + ctx->aead_assoclen = con.aead_assoclen; + } + + while (size) { + struct scatterlist *sg; + size_t len = size; + size_t plen; + + /* use the existing memory in an allocated page */ + if (ctx->merge) { + sgl = list_entry(ctx->tsgl_list.prev, + struct af_alg_tsgl, list); + sg = sgl->sg + sgl->cur - 1; + len = min_t(size_t, len, + PAGE_SIZE - sg->offset - sg->length); + + err = memcpy_from_msg(page_address(sg_page(sg)) + + sg->offset + sg->length, + msg, len); + if (err) + goto unlock; + + sg->length += len; + ctx->merge = (sg->offset + sg->length) & + (PAGE_SIZE - 1); + + ctx->used += len; + copied += len; + size -= len; + continue; + } + + if (!af_alg_writable(sk)) { + err = af_alg_wait_for_wmem(sk, msg->msg_flags); + if (err) + goto unlock; + } + + /* allocate a new page */ + len = min_t(unsigned long, len, af_alg_sndbuf(sk)); + + err = af_alg_alloc_tsgl(sk); + if (err) + goto unlock; + + sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, + list); + sg = sgl->sg; + if (sgl->cur) + sg_unmark_end(sg + sgl->cur - 1); + + do { + unsigned int i = sgl->cur; + + plen = min_t(size_t, len, PAGE_SIZE); + + sg_assign_page(sg + i, alloc_page(GFP_KERNEL)); + if (!sg_page(sg + i)) { + err = -ENOMEM; + goto unlock; + } + + err = memcpy_from_msg(page_address(sg_page(sg + i)), + msg, plen); + if (err) { + __free_page(sg_page(sg + i)); + sg_assign_page(sg + i, NULL); + goto unlock; + } + + sg[i].length = plen; + len -= plen; + ctx->used += plen; + copied += plen; + size -= plen; + sgl->cur++; + } while (len && sgl->cur < MAX_SGL_ENTS); + + if (!size) + sg_mark_end(sg + sgl->cur - 1); + + ctx->merge = plen & (PAGE_SIZE - 1); + } + + err = 0; + + ctx->more = msg->msg_flags & MSG_MORE; + +unlock: + af_alg_data_wakeup(sk); + release_sock(sk); + + return copied ?: err; +} +EXPORT_SYMBOL_GPL(af_alg_sendmsg); + +/** + * af_alg_sendpage - sendpage system call handler + * + * This is a generic implementation of sendpage to fill ctx->tsgl_list. + */ +ssize_t af_alg_sendpage(struct socket *sock, struct page *page, + int offset, size_t size, int flags) +{ + struct sock *sk = sock->sk; + struct alg_sock *ask = alg_sk(sk); + struct af_alg_ctx *ctx = ask->private; + struct af_alg_tsgl *sgl; + int err = -EINVAL; + + if (flags & MSG_SENDPAGE_NOTLAST) + flags |= MSG_MORE; + + lock_sock(sk); + if (!ctx->more && ctx->used) + goto unlock; + + if (!size) + goto done; + + if (!af_alg_writable(sk)) { + err = af_alg_wait_for_wmem(sk, flags); + if (err) + goto unlock; + } + + err = af_alg_alloc_tsgl(sk); + if (err) + goto unlock; + + ctx->merge = 0; + sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list); + + if (sgl->cur) + sg_unmark_end(sgl->sg + sgl->cur - 1); + + sg_mark_end(sgl->sg + sgl->cur); + + get_page(page); + sg_set_page(sgl->sg + sgl->cur, page, size, offset); + sgl->cur++; + ctx->used += size; + +done: + ctx->more = flags & MSG_MORE; + +unlock: + af_alg_data_wakeup(sk); + release_sock(sk); + + return err ?: size; +} +EXPORT_SYMBOL_GPL(af_alg_sendpage); + +/** + * af_alg_free_resources - release resources required for crypto request + */ +void af_alg_free_resources(struct af_alg_async_req *areq) +{ + struct sock *sk = areq->sk; + struct af_alg_ctx *ctx; + + af_alg_free_areq_sgls(areq); + sock_kfree_s(sk, areq, areq->areqlen); + + ctx = alg_sk(sk)->private; + ctx->inflight = false; +} +EXPORT_SYMBOL_GPL(af_alg_free_resources); + +/** + * af_alg_async_cb - AIO callback handler + * + * This handler cleans up the struct af_alg_async_req upon completion of the + * AIO operation. + * + * The number of bytes to be generated with the AIO operation must be set + * in areq->outlen before the AIO callback handler is invoked. + */ +void af_alg_async_cb(struct crypto_async_request *_req, int err) +{ + struct af_alg_async_req *areq = _req->data; + struct sock *sk = areq->sk; + struct kiocb *iocb = areq->iocb; + unsigned int resultlen; + + /* Buffer size written by crypto operation. */ + resultlen = areq->outlen; + + af_alg_free_resources(areq); + sock_put(sk); + + iocb->ki_complete(iocb, err ? err : (int)resultlen, 0); +} +EXPORT_SYMBOL_GPL(af_alg_async_cb); + +/** + * af_alg_poll - poll system call handler + */ +__poll_t af_alg_poll(struct file *file, struct socket *sock, + poll_table *wait) +{ + struct sock *sk = sock->sk; + struct alg_sock *ask = alg_sk(sk); + struct af_alg_ctx *ctx = ask->private; + __poll_t mask; + + sock_poll_wait(file, sock, wait); + mask = 0; + + if (!ctx->more || ctx->used) + mask |= EPOLLIN | EPOLLRDNORM; + + if (af_alg_writable(sk)) + mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND; + + return mask; +} +EXPORT_SYMBOL_GPL(af_alg_poll); + +/** + * af_alg_alloc_areq - allocate struct af_alg_async_req + * + * @sk socket of connection to user space + * @areqlen size of struct af_alg_async_req + crypto_*_reqsize + * @return allocated data structure or ERR_PTR upon error + */ +struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk, + unsigned int areqlen) +{ + struct af_alg_ctx *ctx = alg_sk(sk)->private; + struct af_alg_async_req *areq; + + /* Only one AIO request can be in flight. */ + if (ctx->inflight) + return ERR_PTR(-EBUSY); + + areq = sock_kmalloc(sk, areqlen, GFP_KERNEL); + if (unlikely(!areq)) + return ERR_PTR(-ENOMEM); + + ctx->inflight = true; + + areq->areqlen = areqlen; + areq->sk = sk; + areq->last_rsgl = NULL; + INIT_LIST_HEAD(&areq->rsgl_list); + areq->tsgl = NULL; + areq->tsgl_entries = 0; + + return areq; +} +EXPORT_SYMBOL_GPL(af_alg_alloc_areq); + +/** + * af_alg_get_rsgl - create the RX SGL for the output data from the crypto + * operation + * + * @sk socket of connection to user space + * @msg user space message + * @flags flags used to invoke recvmsg with + * @areq instance of the cryptographic request that will hold the RX SGL + * @maxsize maximum number of bytes to be pulled from user space + * @outlen number of bytes in the RX SGL + * @return 0 on success, < 0 upon error + */ +int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags, + struct af_alg_async_req *areq, size_t maxsize, + size_t *outlen) +{ + struct alg_sock *ask = alg_sk(sk); + struct af_alg_ctx *ctx = ask->private; + size_t len = 0; + + while (maxsize > len && msg_data_left(msg)) { + struct af_alg_rsgl *rsgl; + size_t seglen; + int err; + + /* limit the amount of readable buffers */ + if (!af_alg_readable(sk)) + break; + + seglen = min_t(size_t, (maxsize - len), + msg_data_left(msg)); + + if (list_empty(&areq->rsgl_list)) { + rsgl = &areq->first_rsgl; + } else { + rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL); + if (unlikely(!rsgl)) + return -ENOMEM; + } + + rsgl->sgl.npages = 0; + list_add_tail(&rsgl->list, &areq->rsgl_list); + + /* make one iovec available as scatterlist */ + err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen); + if (err < 0) { + rsgl->sg_num_bytes = 0; + return err; + } + + /* chain the new scatterlist with previous one */ + if (areq->last_rsgl) + af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl); + + areq->last_rsgl = rsgl; + len += err; + atomic_add(err, &ctx->rcvused); + rsgl->sg_num_bytes = err; + iov_iter_advance(&msg->msg_iter, err); + } + + *outlen = len; + return 0; +} +EXPORT_SYMBOL_GPL(af_alg_get_rsgl); + +static int __init af_alg_init(void) +{ + int err = proto_register(&alg_proto, 0); + + if (err) + goto out; + + err = sock_register(&alg_family); + if (err != 0) + goto out_unregister_proto; + +out: + return err; + +out_unregister_proto: + proto_unregister(&alg_proto); + goto out; +} + +static void __exit af_alg_exit(void) +{ + sock_unregister(PF_ALG); + proto_unregister(&alg_proto); +} + +module_init(af_alg_init); +module_exit(af_alg_exit); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NETPROTO(AF_ALG); |