crypto/bio/bf_nbio.c

   1 /*
   2  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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_local.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         BIOerr(BIO_F_NBIOF_NEW, ERR_R_MALLOC_FAILURE);
  62         return 0;
  63     }
  64     nt->lrn = -1;
  65     nt->lwn = -1;
  66     bi->ptr = (char *)nt;
  67     bi->init = 1;
  68     return 1;
  69 }
  70
  71 static int nbiof_free(BIO *a)
  72 {
  73     if (a == NULL)
  74         return 0;
  75     OPENSSL_free(a->ptr);
  76     a->ptr = NULL;
  77     a->init = 0;
  78     a->flags = 0;
  79     return 1;
  80 }
  81
  82 static int nbiof_read(BIO *b, char *out, int outl)
  83 {
  84     int ret = 0;
  85     int num;
  86     unsigned char n;
  87
  88     if (out == NULL)
  89         return 0;
  90     if (b->next_bio == NULL)
  91         return 0;
  92
  93     BIO_clear_retry_flags(b);
  94     if (RAND_priv_bytes(&n, 1) <= 0)
  95         return -1;
  96     num = (n & 0x07);
  97
  98     if (outl > num)
  99         outl = num;
 100
 101     if (num == 0) {
 102         ret = -1;
 103         BIO_set_retry_read(b);
 104     } else {
 105         ret = BIO_read(b->next_bio, out, outl);
 106         if (ret < 0)
 107             BIO_copy_next_retry(b);
 108     }
 109     return ret;
 110 }
 111
 112 static int nbiof_write(BIO *b, const char *in, int inl)
 113 {
 114     NBIO_TEST *nt;
 115     int ret = 0;
 116     int num;
 117     unsigned char n;
 118
 119     if ((in == NULL) || (inl <= 0))
 120         return 0;
 121     if (b->next_bio == NULL)
 122         return 0;
 123     nt = (NBIO_TEST *)b->ptr;
 124
 125     BIO_clear_retry_flags(b);
 126
 127     if (nt->lwn > 0) {
 128         num = nt->lwn;
 129         nt->lwn = 0;
 130     } else {
 131         if (RAND_priv_bytes(&n, 1) <= 0)
 132             return -1;
 133         num = (n & 7);
 134     }
 135
 136     if (inl > num)
 137         inl = num;
 138
 139     if (num == 0) {
 140         ret = -1;
 141         BIO_set_retry_write(b);
 142     } else {
 143         ret = BIO_write(b->next_bio, in, inl);
 144         if (ret < 0) {
 145             BIO_copy_next_retry(b);
 146             nt->lwn = inl;
 147         }
 148     }
 149     return ret;
 150 }
 151
 152 static long nbiof_ctrl(BIO *b, int cmd, long num, void *ptr)
 153 {
 154     long ret;
 155
 156     if (b->next_bio == NULL)
 157         return 0;
 158     switch (cmd) {
 159     case BIO_C_DO_STATE_MACHINE:
 160         BIO_clear_retry_flags(b);
 161         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 162         BIO_copy_next_retry(b);
 163         break;
 164     case BIO_CTRL_DUP:
 165         ret = 0L;
 166         break;
 167     default:
 168         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 169         break;
 170     }
 171     return ret;
 172 }
 173
 174 static long nbiof_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
 175 {
 176     long ret = 1;
 177
 178     if (b->next_bio == NULL)
 179         return 0;
 180     switch (cmd) {
 181     default:
 182         ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
 183         break;
 184     }
 185     return ret;
 186 }
 187
 188 static int nbiof_gets(BIO *bp, char *buf, int size)
 189 {
 190     if (bp->next_bio == NULL)
 191         return 0;
 192     return BIO_gets(bp->next_bio, buf, size);
 193 }
 194
 195 static int nbiof_puts(BIO *bp, const char *str)
 196 {
 197     if (bp->next_bio == NULL)
 198         return 0;
 199     return BIO_puts(bp->next_bio, str);
 200 }