crypto/bio/bf_nbio.c

   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 <stdio.h>
  11 #include <errno.h>
  12 #include "bio_lcl.h"
  13 #include "internal/cryptlib.h"
  14 #include <openssl/rand.h>
  15
  16 /*
  17  * BIO_put and BIO_get both add to the digest, BIO_gets returns the digest
  18  */
  19
  20 static int nbiof_write(BIO *h, const char *buf, int num);
  21 static int nbiof_read(BIO *h, char *buf, int size);
  22 static int nbiof_puts(BIO *h, const char *str);
  23 static int nbiof_gets(BIO *h, char *str, int size);
  24 static long nbiof_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  25 static int nbiof_new(BIO *h);
  26 static int nbiof_free(BIO *data);
  27 static long nbiof_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
  28 typedef struct nbio_test_st {
  29     /* only set if we sent a 'should retry' error */
  30     int lrn;
  31     int lwn;
  32 } NBIO_TEST;
  33
  34 static const BIO_METHOD methods_nbiof = {
  35     BIO_TYPE_NBIO_TEST,
  36     "non-blocking IO test filter",
  37     /* TODO: Convert to new style write function */
  38     bwrite_conv,
  39     nbiof_write,
  40     /* TODO: Convert to new style read function */
  41     bread_conv,
  42     nbiof_read,
  43     nbiof_puts,
  44     nbiof_gets,
  45     nbiof_ctrl,
  46     nbiof_new,
  47     nbiof_free,
  48     nbiof_callback_ctrl,
  49 };
  50
  51 const BIO_METHOD *BIO_f_nbio_test(void)
  52 {
  53     return &methods_nbiof;
  54 }
  55
  56 static int nbiof_new(BIO *bi)
  57 {
  58     NBIO_TEST *nt;
  59
  60     if ((nt = OPENSSL_zalloc(sizeof(*nt))) == NULL)
  61         return 0;
  62     nt->lrn = -1;
  63     nt->lwn = -1;
  64     bi->ptr = (char *)nt;
  65     bi->init = 1;
  66     return 1;
  67 }
  68
  69 static int nbiof_free(BIO *a)
  70 {
  71     if (a == NULL)
  72         return 0;
  73     OPENSSL_free(a->ptr);
  74     a->ptr = NULL;
  75     a->init = 0;
  76     a->flags = 0;
  77     return 1;
  78 }
  79
  80 static int nbiof_read(BIO *b, char *out, int outl)
  81 {
  82     int ret = 0;
  83     int num;
  84     unsigned char n;
  85
  86     if (out == NULL)
  87         return 0;
  88     if (b->next_bio == NULL)
  89         return 0;
  90
  91     BIO_clear_retry_flags(b);
  92     if (RAND_bytes(&n, 1) <= 0)
  93         return -1;
  94     num = (n & 0x07);
  95
  96     if (outl > num)
  97         outl = num;
  98
  99     if (num == 0) {
 100         ret = -1;
 101         BIO_set_retry_read(b);
 102     } else {
 103         ret = BIO_read(b->next_bio, out, outl);
 104         if (ret < 0)
 105             BIO_copy_next_retry(b);
 106     }
 107     return ret;
 108 }
 109
 110 static int nbiof_write(BIO *b, const char *in, int inl)
 111 {
 112     NBIO_TEST *nt;
 113     int ret = 0;
 114     int num;
 115     unsigned char n;
 116
 117     if ((in == NULL) || (inl <= 0))
 118         return 0;
 119     if (b->next_bio == NULL)
 120         return 0;
 121     nt = (NBIO_TEST *)b->ptr;
 122
 123     BIO_clear_retry_flags(b);
 124
 125     if (nt->lwn > 0) {
 126         num = nt->lwn;
 127         nt->lwn = 0;
 128     } else {
 129         if (RAND_bytes(&n, 1) <= 0)
 130             return -1;
 131         num = (n & 7);
 132     }
 133
 134     if (inl > num)
 135         inl = num;
 136
 137     if (num == 0) {
 138         ret = -1;
 139         BIO_set_retry_write(b);
 140     } else {
 141         ret = BIO_write(b->next_bio, in, inl);
 142         if (ret < 0) {
 143             BIO_copy_next_retry(b);
 144             nt->lwn = inl;
 145         }
 146     }
 147     return ret;
 148 }
 149
 150 static long nbiof_ctrl(BIO *b, int cmd, long num, void *ptr)
 151 {
 152     long ret;
 153
 154     if (b->next_bio == NULL)
 155         return 0;
 156     switch (cmd) {
 157     case BIO_C_DO_STATE_MACHINE:
 158         BIO_clear_retry_flags(b);
 159         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 160         BIO_copy_next_retry(b);
 161         break;
 162     case BIO_CTRL_DUP:
 163         ret = 0L;
 164         break;
 165     default:
 166         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 167         break;
 168     }
 169     return ret;
 170 }
 171
 172 static long nbiof_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
 173 {
 174     long ret = 1;
 175
 176     if (b->next_bio == NULL)
 177         return 0;
 178     switch (cmd) {
 179     default:
 180         ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
 181         break;
 182     }
 183     return ret;
 184 }
 185
 186 static int nbiof_gets(BIO *bp, char *buf, int size)
 187 {
 188     if (bp->next_bio == NULL)
 189         return 0;
 190     return BIO_gets(bp->next_bio, buf, size);
 191 }
 192
 193 static int nbiof_puts(BIO *bp, const char *str)
 194 {
 195     if (bp->next_bio == NULL)
 196         return 0;
 197     return BIO_puts(bp->next_bio, str);
 198 }