test/ossl_shim/async_bio.cc

   1 /*
   2  * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include "async_bio.h"
  11
  12 #include <errno.h>
  13 #include <string.h>
  14
  15 #include <openssl/bio.h>
  16 #include <openssl/crypto.h>
  17
  18
  19 namespace {
  20
  21 struct AsyncBio {
  22   bool datagram;
  23   bool enforce_write_quota;
  24   size_t read_quota;
  25   size_t write_quota;
  26 };
  27
  28 AsyncBio *GetData(BIO *bio) {
  29   return (AsyncBio *)BIO_get_data(bio);
  30 }
  31
  32 static int AsyncWrite(BIO *bio, const char *in, int inl) {
  33   AsyncBio *a = GetData(bio);
  34   if (a == NULL || BIO_next(bio) == NULL) {
  35     return 0;
  36   }
  37
  38   if (!a->enforce_write_quota) {
  39     return BIO_write(BIO_next(bio), in, inl);
  40   }
  41
  42   BIO_clear_retry_flags(bio);
  43
  44   if (a->write_quota == 0) {
  45     BIO_set_retry_write(bio);
  46     errno = EAGAIN;
  47     return -1;
  48   }
  49
  50   if (!a->datagram && (size_t)inl > a->write_quota) {
  51     inl = a->write_quota;
  52   }
  53   int ret = BIO_write(BIO_next(bio), in, inl);
  54   if (ret <= 0) {
  55     BIO_copy_next_retry(bio);
  56   } else {
  57     a->write_quota -= (a->datagram ? 1 : ret);
  58   }
  59   return ret;
  60 }
  61
  62 static int AsyncRead(BIO *bio, char *out, int outl) {
  63   AsyncBio *a = GetData(bio);
  64   if (a == NULL || BIO_next(bio) == NULL) {
  65     return 0;
  66   }
  67
  68   BIO_clear_retry_flags(bio);
  69
  70   if (a->read_quota == 0) {
  71     BIO_set_retry_read(bio);
  72     errno = EAGAIN;
  73     return -1;
  74   }
  75
  76   if (!a->datagram && (size_t)outl > a->read_quota) {
  77     outl = a->read_quota;
  78   }
  79   int ret = BIO_read(BIO_next(bio), out, outl);
  80   if (ret <= 0) {
  81     BIO_copy_next_retry(bio);
  82   } else {
  83     a->read_quota -= (a->datagram ? 1 : ret);
  84   }
  85   return ret;
  86 }
  87
  88 static long AsyncCtrl(BIO *bio, int cmd, long num, void *ptr) {
  89   if (BIO_next(bio) == NULL) {
  90     return 0;
  91   }
  92   BIO_clear_retry_flags(bio);
  93   int ret = BIO_ctrl(BIO_next(bio), cmd, num, ptr);
  94   BIO_copy_next_retry(bio);
  95   return ret;
  96 }
  97
  98 static int AsyncNew(BIO *bio) {
  99   AsyncBio *a = (AsyncBio *)OPENSSL_malloc(sizeof(*a));
 100   if (a == NULL) {
 101     return 0;
 102   }
 103   memset(a, 0, sizeof(*a));
 104   a->enforce_write_quota = true;
 105   BIO_set_init(bio, 1);
 106   BIO_set_data(bio, a);
 107   return 1;
 108 }
 109
 110 static int AsyncFree(BIO *bio) {
 111   if (bio == NULL) {
 112     return 0;
 113   }
 114
 115   OPENSSL_free(BIO_get_data(bio));
 116   BIO_set_data(bio, NULL);
 117   BIO_set_init(bio, 0);
 118   return 1;
 119 }
 120
 121 static long AsyncCallbackCtrl(BIO *bio, int cmd, BIO_info_cb fp)
 122 {
 123   if (BIO_next(bio) == NULL)
 124     return 0;
 125   return BIO_callback_ctrl(BIO_next(bio), cmd, fp);
 126 }
 127
 128 static BIO_METHOD *g_async_bio_method = NULL;
 129
 130 static const BIO_METHOD *AsyncMethod(void)
 131 {
 132   if (g_async_bio_method == NULL) {
 133     g_async_bio_method = BIO_meth_new(BIO_TYPE_FILTER, "async bio");
 134     if (   g_async_bio_method == NULL
 135         || !BIO_meth_set_write(g_async_bio_method, AsyncWrite)
 136         || !BIO_meth_set_read(g_async_bio_method, AsyncRead)
 137         || !BIO_meth_set_ctrl(g_async_bio_method, AsyncCtrl)
 138         || !BIO_meth_set_create(g_async_bio_method, AsyncNew)
 139         || !BIO_meth_set_destroy(g_async_bio_method, AsyncFree)
 140         || !BIO_meth_set_callback_ctrl(g_async_bio_method, AsyncCallbackCtrl))
 141     return NULL;
 142   }
 143   return g_async_bio_method;
 144 }
 145
 146 }  // namespace
 147
 148 bssl::UniquePtr<BIO> AsyncBioCreate() {
 149   return bssl::UniquePtr<BIO>(BIO_new(AsyncMethod()));
 150 }
 151
 152 bssl::UniquePtr<BIO> AsyncBioCreateDatagram() {
 153   bssl::UniquePtr<BIO> ret(BIO_new(AsyncMethod()));
 154   if (!ret) {
 155     return nullptr;
 156   }
 157   GetData(ret.get())->datagram = true;
 158   return ret;
 159 }
 160
 161 void AsyncBioAllowRead(BIO *bio, size_t count) {
 162   AsyncBio *a = GetData(bio);
 163   if (a == NULL) {
 164     return;
 165   }
 166   a->read_quota += count;
 167 }
 168
 169 void AsyncBioAllowWrite(BIO *bio, size_t count) {
 170   AsyncBio *a = GetData(bio);
 171   if (a == NULL) {
 172     return;
 173   }
 174   a->write_quota += count;
 175 }
 176
 177 void AsyncBioEnforceWriteQuota(BIO *bio, bool enforce) {
 178   AsyncBio *a = GetData(bio);
 179   if (a == NULL) {
 180     return;
 181   }
 182   a->enforce_write_quota = enforce;
 183 }