linux/crypto/af_alg.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

1195 lines
26 KiB
C

// 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/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 = 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;
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_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;
}
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
* @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
*/
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 = 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, 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_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);