- /* 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 {
-
- extern const BIO_METHOD g_async_bio_method;
-
- struct AsyncBio {
- bool datagram;
- 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->datagram) {
- // Perform writes synchronously; the DTLS implementation drops any packets
- // that failed to send.
- 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));
- 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;
- }
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