diff options
Diffstat (limited to 'crypto/af_alg.c')
| -rw-r--r-- | crypto/af_alg.c | 691 |
1 files changed, 691 insertions, 0 deletions
diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 92a3d540d920..ffa9f4ccd9b4 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -21,6 +21,7 @@ #include <linux/module.h> #include <linux/net.h> #include <linux/rwsem.h> +#include <linux/sched/signal.h> #include <linux/security.h> struct alg_type_list { @@ -507,6 +508,696 @@ void af_alg_complete(struct crypto_async_request *req, int err) } EXPORT_SYMBOL_GPL(af_alg_complete); +/** + * af_alg_alloc_tsgl - allocate the TX SGL + * + * @sk socket of connection to user space + * @return: 0 upon success, < 0 upon error + */ +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, sizeof(*sgl) + + sizeof(sgl->sg[0]) * (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; +} +EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl); + +/** + * 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) +{ + struct alg_sock *ask = alg_sk(sk); + struct af_alg_ctx *ctx = ask->private; + struct af_alg_tsgl *sgl, *tmp; + unsigned int i; + unsigned int sgl_count = 0; + + if (!bytes) + return 0; + + list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) { + 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; + + while (!list_empty(&ctx->tsgl_list)) { + sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl, + list); + sg = sgl->sg; + + for (i = 0, j = 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, sizeof(*sgl) + sizeof(sgl->sg[0]) * + (MAX_SGL_ENTS + 1)); + } + + if (!ctx->used) + ctx->merge = 0; +} +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 + */ +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) { + ctx->rcvused -= rsgl->sg_num_bytes; + 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; + for_each_sg(tsgl, sg, areq->tsgl_entries, i) { + if (!sg_page(sg)) + continue; + put_page(sg_page(sg)); + } + + if (areq->tsgl && areq->tsgl_entries) + sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl)); +} +EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls); + +/** + * 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 + */ +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; +} +EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem); + +/** + * 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, POLLIN | + POLLRDNORM | + POLLRDBAND); + 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 + * @return 0 when writable memory is available, < 0 upon error + */ +int af_alg_wait_for_data(struct sock *sk, unsigned flags) +{ + 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->used || !ctx->more), + &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 + */ + +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, POLLOUT | + POLLRDNORM | + POLLRDBAND); + sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(af_alg_data_wakeup); + +/** + * 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 = 0; + bool init = 0; + int err = 0; + + if (msg->msg_controllen) { + err = af_alg_cmsg_send(msg, &con); + if (err) + return err; + + init = 1; + switch (con.op) { + case ALG_OP_ENCRYPT: + enc = 1; + break; + case ALG_OP_DECRYPT: + enc = 0; + break; + default: + return -EINVAL; + } + + if (con.iv && con.iv->ivlen != ivsize) + return -EINVAL; + } + + lock_sock(sk); + if (!ctx->more && ctx->used) { + err = -EINVAL; + goto unlock; + } + + 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_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; + + lock_sock(sk); + + /* Buffer size written by crypto operation. */ + resultlen = areq->outlen; + + af_alg_free_areq_sgls(areq); + sock_kfree_s(sk, areq, areq->areqlen); + __sock_put(sk); + + iocb->ki_complete(iocb, err ? err : resultlen, 0); + + release_sock(sk); +} +EXPORT_SYMBOL_GPL(af_alg_async_cb); + +/** + * af_alg_poll - poll system call handler + */ +unsigned int 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; + unsigned int mask; + + sock_poll_wait(file, sk_sleep(sk), wait); + mask = 0; + + if (!ctx->more || ctx->used) + mask |= POLLIN | POLLRDNORM; + + if (af_alg_writable(sk)) + mask |= POLLOUT | POLLWRNORM | POLLWRBAND; + + 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_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL); + + if (unlikely(!areq)) + return ERR_PTR(-ENOMEM); + + 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; + + if (!ctx->used) { + err = af_alg_wait_for_data(sk, flags); + if (err) + return err; + } + + 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) + 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; + ctx->rcvused += err; + 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); 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