blob: b75821903e603311d50a1297579e2a5165b13c1e [file] [log] [blame]
/* Copyright (c) 2014, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include "async_bio.h"
#include <errno.h>
#include <string.h>
#include <openssl/mem.h>
namespace bssl {
namespace {
extern const BIO_METHOD g_async_bio_method;
struct AsyncBio {
bool datagram;
bool enforce_write_quota;
size_t read_quota;
size_t write_quota;
};
AsyncBio *GetData(BIO *bio) {
if (bio->method != &g_async_bio_method) {
return NULL;
}
return (AsyncBio *)bio->ptr;
}
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->init = 1;
bio->ptr = (char *)a;
return 1;
}
static int AsyncFree(BIO *bio) {
if (bio == NULL) {
return 0;
}
OPENSSL_free(bio->ptr);
bio->ptr = NULL;
bio->init = 0;
bio->flags = 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);
}
const BIO_METHOD g_async_bio_method = {
BIO_TYPE_FILTER,
"async bio",
AsyncWrite,
AsyncRead,
NULL /* puts */,
NULL /* gets */,
AsyncCtrl,
AsyncNew,
AsyncFree,
AsyncCallbackCtrl,
};
} // namespace
ScopedBIO AsyncBioCreate() {
return ScopedBIO(BIO_new(&g_async_bio_method));
}
ScopedBIO AsyncBioCreateDatagram() {
ScopedBIO ret(BIO_new(&g_async_bio_method));
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;
}
} // namespace bssl