blob: 31d765de92ce97faa104a73458d2d519e468ad7a [file] [log] [blame]
/*
* 2007+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
* All rights reserved.
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/crypto.h>
#include <linux/highmem.h>
#include <linux/kthread.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include "netfs.h"
static struct crypto_hash *pohmelfs_init_hash(struct pohmelfs_sb *psb)
{
int err;
struct crypto_hash *hash;
hash = crypto_alloc_hash(psb->hash_string, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(hash)) {
err = PTR_ERR(hash);
dprintk("%s: idx: %u: failed to allocate hash '%s', err: %d.\n",
__func__, psb->idx, psb->hash_string, err);
goto err_out_exit;
}
psb->crypto_attached_size = crypto_hash_digestsize(hash);
if (!psb->hash_keysize)
return hash;
err = crypto_hash_setkey(hash, psb->hash_key, psb->hash_keysize);
if (err) {
dprintk("%s: idx: %u: failed to set key for hash '%s', err: %d.\n",
__func__, psb->idx, psb->hash_string, err);
goto err_out_free;
}
return hash;
err_out_free:
crypto_free_hash(hash);
err_out_exit:
return ERR_PTR(err);
}
static struct crypto_ablkcipher *pohmelfs_init_cipher(struct pohmelfs_sb *psb)
{
int err = -EINVAL;
struct crypto_ablkcipher *cipher;
if (!psb->cipher_keysize)
goto err_out_exit;
cipher = crypto_alloc_ablkcipher(psb->cipher_string, 0, 0);
if (IS_ERR(cipher)) {
err = PTR_ERR(cipher);
dprintk("%s: idx: %u: failed to allocate cipher '%s', err: %d.\n",
__func__, psb->idx, psb->cipher_string, err);
goto err_out_exit;
}
crypto_ablkcipher_clear_flags(cipher, ~0);
err = crypto_ablkcipher_setkey(cipher, psb->cipher_key, psb->cipher_keysize);
if (err) {
dprintk("%s: idx: %u: failed to set key for cipher '%s', err: %d.\n",
__func__, psb->idx, psb->cipher_string, err);
goto err_out_free;
}
return cipher;
err_out_free:
crypto_free_ablkcipher(cipher);
err_out_exit:
return ERR_PTR(err);
}
int pohmelfs_crypto_engine_init(struct pohmelfs_crypto_engine *e, struct pohmelfs_sb *psb)
{
int err;
e->page_num = 0;
e->size = PAGE_SIZE;
e->data = kmalloc(e->size, GFP_KERNEL);
if (!e->data) {
err = -ENOMEM;
goto err_out_exit;
}
if (psb->hash_string) {
e->hash = pohmelfs_init_hash(psb);
if (IS_ERR(e->hash)) {
err = PTR_ERR(e->hash);
e->hash = NULL;
goto err_out_free;
}
}
if (psb->cipher_string) {
e->cipher = pohmelfs_init_cipher(psb);
if (IS_ERR(e->cipher)) {
err = PTR_ERR(e->cipher);
e->cipher = NULL;
goto err_out_free_hash;
}
}
return 0;
err_out_free_hash:
crypto_free_hash(e->hash);
err_out_free:
kfree(e->data);
err_out_exit:
return err;
}
void pohmelfs_crypto_engine_exit(struct pohmelfs_crypto_engine *e)
{
if (e->hash)
crypto_free_hash(e->hash);
if (e->cipher)
crypto_free_ablkcipher(e->cipher);
kfree(e->data);
}
static void pohmelfs_crypto_complete(struct crypto_async_request *req, int err)
{
struct pohmelfs_crypto_completion *c = req->data;
if (err == -EINPROGRESS)
return;
dprintk("%s: req: %p, err: %d.\n", __func__, req, err);
c->error = err;
complete(&c->complete);
}
static int pohmelfs_crypto_process(struct ablkcipher_request *req,
struct scatterlist *sg_dst, struct scatterlist *sg_src,
void *iv, int enc, unsigned long timeout)
{
struct pohmelfs_crypto_completion complete;
int err;
init_completion(&complete.complete);
complete.error = -EINPROGRESS;
ablkcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
pohmelfs_crypto_complete, &complete);
ablkcipher_request_set_crypt(req, sg_src, sg_dst, sg_src->length, iv);
if (enc)
err = crypto_ablkcipher_encrypt(req);
else
err = crypto_ablkcipher_decrypt(req);
switch (err) {
case -EINPROGRESS:
case -EBUSY:
err = wait_for_completion_interruptible_timeout(&complete.complete,
timeout);
if (!err)
err = -ETIMEDOUT;
else
err = complete.error;
break;
default:
break;
}
return err;
}
int pohmelfs_crypto_process_input_data(struct pohmelfs_crypto_engine *e, u64 cmd_iv,
void *data, struct page *page, unsigned int size)
{
int err;
struct scatterlist sg;
if (!e->cipher && !e->hash)
return 0;
dprintk("%s: eng: %p, iv: %llx, data: %p, page: %p/%lu, size: %u.\n",
__func__, e, cmd_iv, data, page, (page)?page->index:0, size);
if (data) {
sg_init_one(&sg, data, size);
} else {
sg_init_table(&sg, 1);
sg_set_page(&sg, page, size, 0);
}
if (e->cipher) {
struct ablkcipher_request *req = e->data + crypto_hash_digestsize(e->hash);
u8 iv[32];
memset(iv, 0, sizeof(iv));
memcpy(iv, &cmd_iv, sizeof(cmd_iv));
ablkcipher_request_set_tfm(req, e->cipher);
err = pohmelfs_crypto_process(req, &sg, &sg, iv, 0, e->timeout);
if (err)
goto err_out_exit;
}
if (e->hash) {
struct hash_desc desc;
void *dst = e->data + e->size/2;
desc.tfm = e->hash;
desc.flags = 0;
err = crypto_hash_init(&desc);
if (err)
goto err_out_exit;
err = crypto_hash_update(&desc, &sg, size);
if (err)
goto err_out_exit;
err = crypto_hash_final(&desc, dst);
if (err)
goto err_out_exit;
err = !!memcmp(dst, e->data, crypto_hash_digestsize(e->hash));
if (err) {
#ifdef CONFIG_POHMELFS_DEBUG
unsigned int i;
unsigned char *recv = e->data, *calc = dst;
dprintk("%s: eng: %p, hash: %p, cipher: %p: iv : %llx, hash mismatch (recv/calc): ",
__func__, e, e->hash, e->cipher, cmd_iv);
for (i=0; i<crypto_hash_digestsize(e->hash); ++i) {
#if 0
dprintka("%02x ", recv[i]);
if (recv[i] != calc[i]) {
dprintka("| calc byte: %02x.\n", calc[i]);
break;
}
#else
dprintka("%02x/%02x ", recv[i], calc[i]);
#endif
}
dprintk("\n");
#endif
goto err_out_exit;
} else {
dprintk("%s: eng: %p, hash: %p, cipher: %p: hashes matched.\n",
__func__, e, e->hash, e->cipher);
}
}
dprintk("%s: eng: %p, size: %u, hash: %p, cipher: %p: completed.\n",
__func__, e, e->size, e->hash, e->cipher);
return 0;
err_out_exit:
dprintk("%s: eng: %p, hash: %p, cipher: %p: err: %d.\n",
__func__, e, e->hash, e->cipher, err);
return err;
}
static int pohmelfs_trans_iter(struct netfs_trans *t, struct pohmelfs_crypto_engine *e,
int (* iterator) (struct pohmelfs_crypto_engine *e,
struct scatterlist *dst,
struct scatterlist *src))
{
void *data = t->iovec.iov_base + sizeof(struct netfs_cmd) + t->psb->crypto_attached_size;
unsigned int size = t->iovec.iov_len - sizeof(struct netfs_cmd) - t->psb->crypto_attached_size;
struct netfs_cmd *cmd = data;
unsigned int sz, pages = t->attached_pages, i, csize, cmd_cmd, dpage_idx;
struct scatterlist sg_src, sg_dst;
int err;
while (size) {
cmd = data;
cmd_cmd = __be16_to_cpu(cmd->cmd);
csize = __be32_to_cpu(cmd->size);
cmd->iv = __cpu_to_be64(e->iv);
if (cmd_cmd == NETFS_READ_PAGES || cmd_cmd == NETFS_READ_PAGE)
csize = __be16_to_cpu(cmd->ext);
sz = csize + __be16_to_cpu(cmd->cpad) + sizeof(struct netfs_cmd);
dprintk("%s: size: %u, sz: %u, cmd_size: %u, cmd_cpad: %u.\n",
__func__, size, sz, __be32_to_cpu(cmd->size), __be16_to_cpu(cmd->cpad));
data += sz;
size -= sz;
sg_init_one(&sg_src, cmd->data, sz - sizeof(struct netfs_cmd));
sg_init_one(&sg_dst, cmd->data, sz - sizeof(struct netfs_cmd));
err = iterator(e, &sg_dst, &sg_src);
if (err)
return err;
}
if (!pages)
return 0;
dpage_idx = 0;
for (i=0; i<t->page_num; ++i) {
struct page *page = t->pages[i];
struct page *dpage = e->pages[dpage_idx];
if (!page)
continue;
sg_init_table(&sg_src, 1);
sg_init_table(&sg_dst, 1);
sg_set_page(&sg_src, page, page_private(page), 0);
sg_set_page(&sg_dst, dpage, page_private(page), 0);
err = iterator(e, &sg_dst, &sg_src);
if (err)
return err;
pages--;
if (!pages)
break;
dpage_idx++;
}
return 0;
}
static int pohmelfs_encrypt_iterator(struct pohmelfs_crypto_engine *e,
struct scatterlist *sg_dst, struct scatterlist *sg_src)
{
struct ablkcipher_request *req = e->data;
u8 iv[32];
memset(iv, 0, sizeof(iv));
memcpy(iv, &e->iv, sizeof(e->iv));
return pohmelfs_crypto_process(req, sg_dst, sg_src, iv, 1, e->timeout);
}
static int pohmelfs_encrypt(struct pohmelfs_crypto_thread *tc)
{
struct netfs_trans *t = tc->trans;
struct pohmelfs_crypto_engine *e = &tc->eng;
struct ablkcipher_request *req = e->data;
memset(req, 0, sizeof(struct ablkcipher_request));
ablkcipher_request_set_tfm(req, e->cipher);
e->iv = pohmelfs_gen_iv(t);
return pohmelfs_trans_iter(t, e, pohmelfs_encrypt_iterator);
}
static int pohmelfs_hash_iterator(struct pohmelfs_crypto_engine *e,
struct scatterlist *sg_dst, struct scatterlist *sg_src)
{
return crypto_hash_update(e->data, sg_src, sg_src->length);
}
static int pohmelfs_hash(struct pohmelfs_crypto_thread *tc)
{
struct pohmelfs_crypto_engine *e = &tc->eng;
struct hash_desc *desc = e->data;
unsigned char *dst = tc->trans->iovec.iov_base + sizeof(struct netfs_cmd);
int err;
desc->tfm = e->hash;
desc->flags = 0;
err = crypto_hash_init(desc);
if (err)
return err;
err = pohmelfs_trans_iter(tc->trans, e, pohmelfs_hash_iterator);
if (err)
return err;
err = crypto_hash_final(desc, dst);
if (err)
return err;
{
unsigned int i;
dprintk("%s: ", __func__);
for (i=0; i<tc->psb->crypto_attached_size; ++i)
dprintka("%02x ", dst[i]);
dprintka("\n");
}
return 0;
}
static void pohmelfs_crypto_pages_free(struct pohmelfs_crypto_engine *e)
{
unsigned int i;
for (i=0; i<e->page_num; ++i)
__free_page(e->pages[i]);
kfree(e->pages);
}
static int pohmelfs_crypto_pages_alloc(struct pohmelfs_crypto_engine *e, struct pohmelfs_sb *psb)
{
unsigned int i;
e->pages = kmalloc(psb->trans_max_pages * sizeof(struct page *), GFP_KERNEL);
if (!e->pages)
return -ENOMEM;
for (i=0; i<psb->trans_max_pages; ++i) {
e->pages[i] = alloc_page(GFP_KERNEL);
if (!e->pages[i])
break;
}
e->page_num = i;
if (!e->page_num)
goto err_out_free;
return 0;
err_out_free:
kfree(e->pages);
return -ENOMEM;
}
static void pohmelfs_sys_crypto_exit_one(struct pohmelfs_crypto_thread *t)
{
struct pohmelfs_sb *psb = t->psb;
if (t->thread)
kthread_stop(t->thread);
mutex_lock(&psb->crypto_thread_lock);
list_del(&t->thread_entry);
psb->crypto_thread_num--;
mutex_unlock(&psb->crypto_thread_lock);
pohmelfs_crypto_engine_exit(&t->eng);
pohmelfs_crypto_pages_free(&t->eng);
kfree(t);
}
static int pohmelfs_crypto_finish(struct netfs_trans *t, struct pohmelfs_sb *psb, int err)
{
struct netfs_cmd *cmd = t->iovec.iov_base;
netfs_convert_cmd(cmd);
if (likely(!err))
err = netfs_trans_finish_send(t, psb);
t->result = err;
netfs_trans_put(t);
return err;
}
void pohmelfs_crypto_thread_make_ready(struct pohmelfs_crypto_thread *th)
{
struct pohmelfs_sb *psb = th->psb;
th->page = NULL;
th->trans = NULL;
mutex_lock(&psb->crypto_thread_lock);
list_move_tail(&th->thread_entry, &psb->crypto_ready_list);
mutex_unlock(&psb->crypto_thread_lock);
wake_up(&psb->wait);
}
static int pohmelfs_crypto_thread_trans(struct pohmelfs_crypto_thread *t)
{
struct netfs_trans *trans;
int err = 0;
trans = t->trans;
trans->eng = NULL;
if (t->eng.hash) {
err = pohmelfs_hash(t);
if (err)
goto out_complete;
}
if (t->eng.cipher) {
err = pohmelfs_encrypt(t);
if (err)
goto out_complete;
trans->eng = &t->eng;
}
out_complete:
t->page = NULL;
t->trans = NULL;
if (!trans->eng)
pohmelfs_crypto_thread_make_ready(t);
pohmelfs_crypto_finish(trans, t->psb, err);
return err;
}
static int pohmelfs_crypto_thread_page(struct pohmelfs_crypto_thread *t)
{
struct pohmelfs_crypto_engine *e = &t->eng;
struct page *page = t->page;
int err;
WARN_ON(!PageChecked(page));
err = pohmelfs_crypto_process_input_data(e, e->iv, NULL, page, t->size);
if (!err)
SetPageUptodate(page);
else
SetPageError(page);
unlock_page(page);
page_cache_release(page);
pohmelfs_crypto_thread_make_ready(t);
return err;
}
static int pohmelfs_crypto_thread_func(void *data)
{
struct pohmelfs_crypto_thread *t = data;
while (!kthread_should_stop()) {
wait_event_interruptible(t->wait, kthread_should_stop() ||
t->trans || t->page);
if (kthread_should_stop())
break;
if (!t->trans && !t->page)
continue;
dprintk("%s: thread: %p, trans: %p, page: %p.\n",
__func__, t, t->trans, t->page);
if (t->trans)
pohmelfs_crypto_thread_trans(t);
else if (t->page)
pohmelfs_crypto_thread_page(t);
}
return 0;
}
static void pohmelfs_crypto_flush(struct pohmelfs_sb *psb, struct list_head *head)
{
while (!list_empty(head)) {
struct pohmelfs_crypto_thread *t = NULL;
mutex_lock(&psb->crypto_thread_lock);
if (!list_empty(head)) {
t = list_first_entry(head, struct pohmelfs_crypto_thread, thread_entry);
list_del_init(&t->thread_entry);
}
mutex_unlock(&psb->crypto_thread_lock);
if (t)
pohmelfs_sys_crypto_exit_one(t);
}
}
static void pohmelfs_sys_crypto_exit(struct pohmelfs_sb *psb)
{
while (!list_empty(&psb->crypto_active_list) || !list_empty(&psb->crypto_ready_list)) {
dprintk("%s: crypto_thread_num: %u.\n", __func__, psb->crypto_thread_num);
pohmelfs_crypto_flush(psb, &psb->crypto_active_list);
pohmelfs_crypto_flush(psb, &psb->crypto_ready_list);
}
}
static int pohmelfs_sys_crypto_init(struct pohmelfs_sb *psb)
{
unsigned int i;
struct pohmelfs_crypto_thread *t;
struct pohmelfs_config *c;
struct netfs_state *st;
int err;
list_for_each_entry(c, &psb->state_list, config_entry) {
st = &c->state;
err = pohmelfs_crypto_engine_init(&st->eng, psb);
if (err)
goto err_out_exit;
dprintk("%s: st: %p, eng: %p, hash: %p, cipher: %p.\n",
__func__, st, &st->eng, &st->eng.hash, &st->eng.cipher);
}
for (i=0; i<psb->crypto_thread_num; ++i) {
err = -ENOMEM;
t = kzalloc(sizeof(struct pohmelfs_crypto_thread), GFP_KERNEL);
if (!t)
goto err_out_free_state_engines;
init_waitqueue_head(&t->wait);
t->psb = psb;
t->trans = NULL;
t->eng.thread = t;
err = pohmelfs_crypto_engine_init(&t->eng, psb);
if (err)
goto err_out_free_state_engines;
err = pohmelfs_crypto_pages_alloc(&t->eng, psb);
if (err)
goto err_out_free;
t->thread = kthread_run(pohmelfs_crypto_thread_func, t,
"pohmelfs-crypto-%d-%d", psb->idx, i);
if (IS_ERR(t->thread)) {
err = PTR_ERR(t->thread);
t->thread = NULL;
goto err_out_free;
}
if (t->eng.cipher)
psb->crypto_align_size = crypto_ablkcipher_blocksize(t->eng.cipher);
mutex_lock(&psb->crypto_thread_lock);
list_add_tail(&t->thread_entry, &psb->crypto_ready_list);
mutex_unlock(&psb->crypto_thread_lock);
}
psb->crypto_thread_num = i;
return 0;
err_out_free:
pohmelfs_sys_crypto_exit_one(t);
err_out_free_state_engines:
list_for_each_entry(c, &psb->state_list, config_entry) {
st = &c->state;
pohmelfs_crypto_engine_exit(&st->eng);
}
err_out_exit:
pohmelfs_sys_crypto_exit(psb);
return err;
}
void pohmelfs_crypto_exit(struct pohmelfs_sb *psb)
{
pohmelfs_sys_crypto_exit(psb);
kfree(psb->hash_string);
kfree(psb->cipher_string);
}
static int pohmelfs_crypt_init_complete(struct page **pages, unsigned int page_num,
void *private, int err)
{
struct pohmelfs_sb *psb = private;
psb->flags = -err;
dprintk("%s: err: %d.\n", __func__, err);
wake_up(&psb->wait);
return err;
}
static int pohmelfs_crypto_init_handshake(struct pohmelfs_sb *psb)
{
struct netfs_trans *t;
struct netfs_crypto_capabilities *cap;
struct netfs_cmd *cmd;
char *str;
int err = -ENOMEM, size;
size = sizeof(struct netfs_crypto_capabilities) +
psb->cipher_strlen + psb->hash_strlen + 2; /* 0 bytes */
t = netfs_trans_alloc(psb, size, 0, 0);
if (!t)
goto err_out_exit;
t->complete = pohmelfs_crypt_init_complete;
t->private = psb;
cmd = netfs_trans_current(t);
cap = (struct netfs_crypto_capabilities *)(cmd + 1);
str = (char *)(cap + 1);
cmd->cmd = NETFS_CAPABILITIES;
cmd->id = POHMELFS_CRYPTO_CAPABILITIES;
cmd->size = size;
cmd->start = 0;
cmd->ext = 0;
cmd->csize = 0;
netfs_convert_cmd(cmd);
netfs_trans_update(cmd, t, size);
cap->hash_strlen = psb->hash_strlen;
if (cap->hash_strlen) {
sprintf(str, "%s", psb->hash_string);
str += cap->hash_strlen;
}
cap->cipher_strlen = psb->cipher_strlen;
cap->cipher_keysize = psb->cipher_keysize;
if (cap->cipher_strlen)
sprintf(str, "%s", psb->cipher_string);
netfs_convert_crypto_capabilities(cap);
psb->flags = ~0;
err = netfs_trans_finish(t, psb);
if (err)
goto err_out_exit;
err = wait_event_interruptible_timeout(psb->wait, (psb->flags != ~0),
psb->wait_on_page_timeout);
if (!err)
err = -ETIMEDOUT;
else
err = -psb->flags;
if (!err)
psb->perform_crypto = 1;
psb->flags = 0;
/*
* At this point NETFS_CAPABILITIES response command
* should setup superblock in a way, which is acceptible
* for both client and server, so if server refuses connection,
* it will send error in transaction response.
*/
if (err)
goto err_out_exit;
return 0;
err_out_exit:
return err;
}
int pohmelfs_crypto_init(struct pohmelfs_sb *psb)
{
int err;
if (!psb->cipher_string && !psb->hash_string)
return 0;
err = pohmelfs_crypto_init_handshake(psb);
if (err)
return err;
err = pohmelfs_sys_crypto_init(psb);
if (err)
return err;
return 0;
}
static int pohmelfs_crypto_thread_get(struct pohmelfs_sb *psb,
int (* action)(struct pohmelfs_crypto_thread *t, void *data), void *data)
{
struct pohmelfs_crypto_thread *t = NULL;
int err;
while (!t) {
err = wait_event_interruptible_timeout(psb->wait,
!list_empty(&psb->crypto_ready_list),
psb->wait_on_page_timeout);
t = NULL;
err = 0;
mutex_lock(&psb->crypto_thread_lock);
if (!list_empty(&psb->crypto_ready_list)) {
t = list_entry(psb->crypto_ready_list.prev,
struct pohmelfs_crypto_thread,
thread_entry);
list_move_tail(&t->thread_entry,
&psb->crypto_active_list);
action(t, data);
wake_up(&t->wait);
}
mutex_unlock(&psb->crypto_thread_lock);
}
return err;
}
static int pohmelfs_trans_crypt_action(struct pohmelfs_crypto_thread *t, void *data)
{
struct netfs_trans *trans = data;
netfs_trans_get(trans);
t->trans = trans;
dprintk("%s: t: %p, gen: %u, thread: %p.\n", __func__, trans, trans->gen, t);
return 0;
}
int pohmelfs_trans_crypt(struct netfs_trans *trans, struct pohmelfs_sb *psb)
{
if ((!psb->hash_string && !psb->cipher_string) || !psb->perform_crypto) {
netfs_trans_get(trans);
return pohmelfs_crypto_finish(trans, psb, 0);
}
return pohmelfs_crypto_thread_get(psb, pohmelfs_trans_crypt_action, trans);
}
struct pohmelfs_crypto_input_action_data
{
struct page *page;
struct pohmelfs_crypto_engine *e;
u64 iv;
unsigned int size;
};
static int pohmelfs_crypt_input_page_action(struct pohmelfs_crypto_thread *t, void *data)
{
struct pohmelfs_crypto_input_action_data *act = data;
memcpy(t->eng.data, act->e->data, t->psb->crypto_attached_size);
t->size = act->size;
t->eng.iv = act->iv;
t->page = act->page;
return 0;
}
int pohmelfs_crypto_process_input_page(struct pohmelfs_crypto_engine *e,
struct page *page, unsigned int size, u64 iv)
{
struct inode *inode = page->mapping->host;
struct pohmelfs_crypto_input_action_data act;
int err = -ENOENT;
act.page = page;
act.e = e;
act.size = size;
act.iv = iv;
err = pohmelfs_crypto_thread_get(POHMELFS_SB(inode->i_sb),
pohmelfs_crypt_input_page_action, &act);
if (err)
goto err_out_exit;
return 0;
err_out_exit:
SetPageUptodate(page);
page_cache_release(page);
return err;
}