/* * 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> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. * */ #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/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); 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 = ask->nokey_refcnt; bool last = nokey && !ask->refcnt; sk = ask->parent; ask = alg_sk(sk); lock_sock(sk); ask->nokey_refcnt -= nokey; if (!last) last = !--ask->refcnt; release_sock(sk); if (last) 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 *sa = (void *)uaddr; const struct af_alg_type *type; void *private; int err; if (sock->state == SS_CONNECTED) return -EINVAL; if (addr_len < sizeof(*sa)) 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[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0; type = alg_get_type(sa->salg_type); if (IS_ERR(type) && 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 (ask->refcnt | ask->nokey_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, char __user *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_user(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, char __user *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 (ask->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); } 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); 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; sk2->sk_family = PF_ALG; if (nokey || !ask->refcnt++) sock_hold(sk); ask->nokey_refcnt += nokey; alg_sk(sk2)->parent = sk; alg_sk(sk2)->type = type; alg_sk(sk2)->nokey_refcnt = nokey; newsock->ops = type->ops; 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, .getsockopt = sock_no_getsockopt, .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_family = PF_ALG; 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); 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); } EXPORT_SYMBOL_GPL(af_alg_link_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); 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; } EXPORT_SYMBOL_GPL(af_alg_cmsg_send); /** * 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, 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; } 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 = 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, 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) { 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)); } } 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, 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 * @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, EPOLLOUT | EPOLLRDNORM | EPOLLRDBAND); 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_free_resources - release resources required for crypto request */ void af_alg_free_resources(struct af_alg_async_req *areq) { struct sock *sk = areq->sk; af_alg_free_areq_sgls(areq); sock_kfree_s(sk, areq, areq->areqlen); } 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 : 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, 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_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; 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);