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/*
* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include "async_bio.h"
#include <errno.h>
#include <string.h>
#include <openssl/bio.h>
#include <openssl/crypto.h>
namespace {
struct AsyncBio {
bool datagram;
bool enforce_write_quota;
size_t read_quota;
size_t write_quota;
};
AsyncBio *GetData(BIO *bio) {
return (AsyncBio *)BIO_get_data(bio);
}
static int AsyncWrite(BIO *bio, const char *in, int inl) {
AsyncBio *a = GetData(bio);
if (a == NULL || BIO_next(bio) == NULL) {
return 0;
}
if (!a->enforce_write_quota) {
return BIO_write(BIO_next(bio), in, inl);
}
BIO_clear_retry_flags(bio);
if (a->write_quota == 0) {
BIO_set_retry_write(bio);
errno = EAGAIN;
return -1;
}
if (!a->datagram && (size_t)inl > a->write_quota) {
inl = a->write_quota;
}
int ret = BIO_write(BIO_next(bio), in, inl);
if (ret <= 0) {
BIO_copy_next_retry(bio);
} else {
a->write_quota -= (a->datagram ? 1 : ret);
}
return ret;
}
static int AsyncRead(BIO *bio, char *out, int outl) {
AsyncBio *a = GetData(bio);
if (a == NULL || BIO_next(bio) == NULL) {
return 0;
}
BIO_clear_retry_flags(bio);
if (a->read_quota == 0) {
BIO_set_retry_read(bio);
errno = EAGAIN;
return -1;
}
if (!a->datagram && (size_t)outl > a->read_quota) {
outl = a->read_quota;
}
int ret = BIO_read(BIO_next(bio), out, outl);
if (ret <= 0) {
BIO_copy_next_retry(bio);
} else {
a->read_quota -= (a->datagram ? 1 : ret);
}
return ret;
}
static long AsyncCtrl(BIO *bio, int cmd, long num, void *ptr) {
if (BIO_next(bio) == NULL) {
return 0;
}
BIO_clear_retry_flags(bio);
int ret = BIO_ctrl(BIO_next(bio), cmd, num, ptr);
BIO_copy_next_retry(bio);
return ret;
}
static int AsyncNew(BIO *bio) {
AsyncBio *a = (AsyncBio *)OPENSSL_malloc(sizeof(*a));
if (a == NULL) {
return 0;
}
memset(a, 0, sizeof(*a));
a->enforce_write_quota = true;
BIO_set_init(bio, 1);
BIO_set_data(bio, a);
return 1;
}
static int AsyncFree(BIO *bio) {
if (bio == NULL) {
return 0;
}
OPENSSL_free(BIO_get_data(bio));
BIO_set_data(bio, NULL);
BIO_set_init(bio, 0);
return 1;
}
static long AsyncCallbackCtrl(BIO *bio, int cmd, BIO_info_cb fp)
{
if (BIO_next(bio) == NULL)
return 0;
return BIO_callback_ctrl(BIO_next(bio), cmd, fp);
}
static BIO_METHOD *g_async_bio_method = NULL;
static const BIO_METHOD *AsyncMethod(void)
{
if (g_async_bio_method == NULL) {
g_async_bio_method = BIO_meth_new(BIO_TYPE_FILTER, "async bio");
if ( g_async_bio_method == NULL
|| !BIO_meth_set_write(g_async_bio_method, AsyncWrite)
|| !BIO_meth_set_read(g_async_bio_method, AsyncRead)
|| !BIO_meth_set_ctrl(g_async_bio_method, AsyncCtrl)
|| !BIO_meth_set_create(g_async_bio_method, AsyncNew)
|| !BIO_meth_set_destroy(g_async_bio_method, AsyncFree)
|| !BIO_meth_set_callback_ctrl(g_async_bio_method, AsyncCallbackCtrl))
return NULL;
}
return g_async_bio_method;
}
} // namespace
bssl::UniquePtr<BIO> AsyncBioCreate() {
return bssl::UniquePtr<BIO>(BIO_new(AsyncMethod()));
}
bssl::UniquePtr<BIO> AsyncBioCreateDatagram() {
bssl::UniquePtr<BIO> ret(BIO_new(AsyncMethod()));
if (!ret) {
return nullptr;
}
GetData(ret.get())->datagram = true;
return ret;
}
void AsyncBioAllowRead(BIO *bio, size_t count) {
AsyncBio *a = GetData(bio);
if (a == NULL) {
return;
}
a->read_quota += count;
}
void AsyncBioAllowWrite(BIO *bio, size_t count) {
AsyncBio *a = GetData(bio);
if (a == NULL) {
return;
}
a->write_quota += count;
}
void AsyncBioEnforceWriteQuota(BIO *bio, bool enforce) {
AsyncBio *a = GetData(bio);
if (a == NULL) {
return;
}
a->enforce_write_quota = enforce;
}
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