1 /* Copyright (c) 2014, Google Inc. 2 * 3 * Permission to use, copy, modify, and/or distribute this software for any 4 * purpose with or without fee is hereby granted, provided that the above 5 * copyright notice and this permission notice appear in all copies. 6 * 7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ 14 15 #include "async_bio.h" 16 17 #include <errno.h> 18 #include <openssl/mem.h> 19 20 namespace { 21 22 extern const BIO_METHOD async_bio_method; 23 24 struct async_bio { 25 bool datagram; 26 size_t read_quota; 27 size_t write_quota; 28 }; 29 30 async_bio *get_data(BIO *bio) { 31 if (bio->method != &async_bio_method) { 32 return NULL; 33 } 34 return (async_bio *)bio->ptr; 35 } 36 37 static int async_write(BIO *bio, const char *in, int inl) { 38 async_bio *a = get_data(bio); 39 if (a == NULL || bio->next_bio == NULL) { 40 return 0; 41 } 42 43 if (a->datagram) { 44 // Perform writes synchronously; the DTLS implementation drops any packets 45 // that failed to send. 46 return BIO_write(bio->next_bio, in, inl); 47 } 48 49 BIO_clear_retry_flags(bio); 50 51 if (a->write_quota == 0) { 52 BIO_set_retry_write(bio); 53 errno = EAGAIN; 54 return -1; 55 } 56 57 if (!a->datagram && (size_t)inl > a->write_quota) { 58 inl = a->write_quota; 59 } 60 int ret = BIO_write(bio->next_bio, in, inl); 61 if (ret <= 0) { 62 BIO_copy_next_retry(bio); 63 } else { 64 a->write_quota -= ret; 65 } 66 return ret; 67 } 68 69 static int async_read(BIO *bio, char *out, int outl) { 70 async_bio *a = get_data(bio); 71 if (a == NULL || bio->next_bio == NULL) { 72 return 0; 73 } 74 75 BIO_clear_retry_flags(bio); 76 77 if (a->read_quota == 0) { 78 BIO_set_retry_read(bio); 79 errno = EAGAIN; 80 return -1; 81 } 82 83 if (!a->datagram && (size_t)outl > a->read_quota) { 84 outl = a->read_quota; 85 } 86 int ret = BIO_read(bio->next_bio, out, outl); 87 if (ret <= 0) { 88 BIO_copy_next_retry(bio); 89 } else { 90 a->read_quota -= (a->datagram ? 1 : ret); 91 } 92 return ret; 93 } 94 95 static long async_ctrl(BIO *bio, int cmd, long num, void *ptr) { 96 if (bio->next_bio == NULL) { 97 return 0; 98 } 99 BIO_clear_retry_flags(bio); 100 int ret = BIO_ctrl(bio->next_bio, cmd, num, ptr); 101 BIO_copy_next_retry(bio); 102 return ret; 103 } 104 105 static int async_new(BIO *bio) { 106 async_bio *a = (async_bio *)OPENSSL_malloc(sizeof(*a)); 107 if (a == NULL) { 108 return 0; 109 } 110 memset(a, 0, sizeof(*a)); 111 bio->init = 1; 112 bio->ptr = (char *)a; 113 return 1; 114 } 115 116 static int async_free(BIO *bio) { 117 if (bio == NULL) { 118 return 0; 119 } 120 121 OPENSSL_free(bio->ptr); 122 bio->ptr = NULL; 123 bio->init = 0; 124 bio->flags = 0; 125 return 1; 126 } 127 128 static long async_callback_ctrl(BIO *bio, int cmd, bio_info_cb fp) { 129 if (bio->next_bio == NULL) { 130 return 0; 131 } 132 return BIO_callback_ctrl(bio->next_bio, cmd, fp); 133 } 134 135 const BIO_METHOD async_bio_method = { 136 BIO_TYPE_FILTER, 137 "async bio", 138 async_write, 139 async_read, 140 NULL /* puts */, 141 NULL /* gets */, 142 async_ctrl, 143 async_new, 144 async_free, 145 async_callback_ctrl, 146 }; 147 148 } // namespace 149 150 BIO *async_bio_create() { 151 return BIO_new(&async_bio_method); 152 } 153 154 BIO *async_bio_create_datagram() { 155 BIO *ret = BIO_new(&async_bio_method); 156 if (!ret) { 157 return NULL; 158 } 159 get_data(ret)->datagram = true; 160 return ret; 161 } 162 163 void async_bio_allow_read(BIO *bio, size_t count) { 164 async_bio *a = get_data(bio); 165 if (a == NULL) { 166 return; 167 } 168 a->read_quota += count; 169 } 170 171 void async_bio_allow_write(BIO *bio, size_t count) { 172 async_bio *a = get_data(bio); 173 if (a == NULL) { 174 return; 175 } 176 a->write_quota += count; 177 } 178