crypto/bio/bss_fd.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
  13 #include "bio_lcl.h"
  14
  15 #if defined(OPENSSL_NO_POSIX_IO)
  16 /*
  17  * Dummy placeholder for BIO_s_fd...
  18  */
  19 BIO *BIO_new_fd(int fd, int close_flag)
  20 {
  21     return NULL;
  22 }
  23
  24 int BIO_fd_non_fatal_error(int err)
  25 {
  26     return 0;
  27 }
  28
  29 int BIO_fd_should_retry(int i)
  30 {
  31     return 0;
  32 }
  33
  34 const BIO_METHOD *BIO_s_fd(void)
  35 {
  36     return NULL;
  37 }
  38 #else
  39 /*
  40  * As for unconditional usage of "UPLINK" interface in this module.
  41  * Trouble is that unlike Unix file descriptors [which are indexes
  42  * in kernel-side per-process table], corresponding descriptors on
  43  * platforms which require "UPLINK" interface seem to be indexes
  44  * in a user-land, non-global table. Well, in fact they are indexes
  45  * in stdio _iob[], and recall that _iob[] was the very reason why
  46  * "UPLINK" interface was introduced in first place. But one way on
  47  * another. Neither libcrypto or libssl use this BIO meaning that
  48  * file descriptors can only be provided by application. Therefore
  49  * "UPLINK" calls are due...
  50  */
  51 static int fd_write(BIO *h, const char *buf, int num);
  52 static int fd_read(BIO *h, char *buf, int size);
  53 static int fd_puts(BIO *h, const char *str);
  54 static int fd_gets(BIO *h, char *buf, int size);
  55 static long fd_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  56 static int fd_new(BIO *h);
  57 static int fd_free(BIO *data);
  58 int BIO_fd_should_retry(int s);
  59
  60 static const BIO_METHOD methods_fdp = {
  61     BIO_TYPE_FD, "file descriptor",
  62     /* TODO: Convert to new style write function */
  63     bwrite_conv,
  64     fd_write,
  65     /* TODO: Convert to new style read function */
  66     bread_conv,
  67     fd_read,
  68     fd_puts,
  69     fd_gets,
  70     fd_ctrl,
  71     fd_new,
  72     fd_free,
  73     NULL,
  74 };
  75
  76 const BIO_METHOD *BIO_s_fd(void)
  77 {
  78     return (&methods_fdp);
  79 }
  80
  81 BIO *BIO_new_fd(int fd, int close_flag)
  82 {
  83     BIO *ret;
  84     ret = BIO_new(BIO_s_fd());
  85     if (ret == NULL)
  86         return (NULL);
  87     BIO_set_fd(ret, fd, close_flag);
  88     return (ret);
  89 }
  90
  91 static int fd_new(BIO *bi)
  92 {
  93     bi->init = 0;
  94     bi->num = -1;
  95     bi->ptr = NULL;
  96     bi->flags = BIO_FLAGS_UPLINK; /* essentially redundant */
  97     return (1);
  98 }
  99
 100 static int fd_free(BIO *a)
 101 {
 102     if (a == NULL)
 103         return (0);
 104     if (a->shutdown) {
 105         if (a->init) {
 106             UP_close(a->num);
 107         }
 108         a->init = 0;
 109         a->flags = BIO_FLAGS_UPLINK;
 110     }
 111     return (1);
 112 }
 113
 114 static int fd_read(BIO *b, char *out, int outl)
 115 {
 116     int ret = 0;
 117
 118     if (out != NULL) {
 119         clear_sys_error();
 120         ret = UP_read(b->num, out, outl);
 121         BIO_clear_retry_flags(b);
 122         if (ret <= 0) {
 123             if (BIO_fd_should_retry(ret))
 124                 BIO_set_retry_read(b);
 125         }
 126     }
 127     return (ret);
 128 }
 129
 130 static int fd_write(BIO *b, const char *in, int inl)
 131 {
 132     int ret;
 133     clear_sys_error();
 134     ret = UP_write(b->num, in, inl);
 135     BIO_clear_retry_flags(b);
 136     if (ret <= 0) {
 137         if (BIO_fd_should_retry(ret))
 138             BIO_set_retry_write(b);
 139     }
 140     return (ret);
 141 }
 142
 143 static long fd_ctrl(BIO *b, int cmd, long num, void *ptr)
 144 {
 145     long ret = 1;
 146     int *ip;
 147
 148     switch (cmd) {
 149     case BIO_CTRL_RESET:
 150         num = 0;
 151         /* fall thru */
 152     case BIO_C_FILE_SEEK:
 153         ret = (long)UP_lseek(b->num, num, 0);
 154         break;
 155     case BIO_C_FILE_TELL:
 156     case BIO_CTRL_INFO:
 157         ret = (long)UP_lseek(b->num, 0, 1);
 158         break;
 159     case BIO_C_SET_FD:
 160         fd_free(b);
 161         b->num = *((int *)ptr);
 162         b->shutdown = (int)num;
 163         b->init = 1;
 164         break;
 165     case BIO_C_GET_FD:
 166         if (b->init) {
 167             ip = (int *)ptr;
 168             if (ip != NULL)
 169                 *ip = b->num;
 170             ret = b->num;
 171         } else
 172             ret = -1;
 173         break;
 174     case BIO_CTRL_GET_CLOSE:
 175         ret = b->shutdown;
 176         break;
 177     case BIO_CTRL_SET_CLOSE:
 178         b->shutdown = (int)num;
 179         break;
 180     case BIO_CTRL_PENDING:
 181     case BIO_CTRL_WPENDING:
 182         ret = 0;
 183         break;
 184     case BIO_CTRL_DUP:
 185     case BIO_CTRL_FLUSH:
 186         ret = 1;
 187         break;
 188     default:
 189         ret = 0;
 190         break;
 191     }
 192     return (ret);
 193 }
 194
 195 static int fd_puts(BIO *bp, const char *str)
 196 {
 197     int n, ret;
 198
 199     n = strlen(str);
 200     ret = fd_write(bp, str, n);
 201     return (ret);
 202 }
 203
 204 static int fd_gets(BIO *bp, char *buf, int size)
 205 {
 206     int ret = 0;
 207     char *ptr = buf;
 208     char *end = buf + size - 1;
 209
 210     while ((ptr < end) && (fd_read(bp, ptr, 1) > 0) && (ptr[0] != '\n'))
 211         ptr++;
 212
 213     ptr[0] = '\0';
 214
 215     if (buf[0] != '\0')
 216         ret = strlen(buf);
 217     return (ret);
 218 }
 219
 220 int BIO_fd_should_retry(int i)
 221 {
 222     int err;
 223
 224     if ((i == 0) || (i == -1)) {
 225         err = get_last_sys_error();
 226
 227         return (BIO_fd_non_fatal_error(err));
 228     }
 229     return (0);
 230 }
 231
 232 int BIO_fd_non_fatal_error(int err)
 233 {
 234     switch (err) {
 235
 236 # ifdef EWOULDBLOCK
 237 #  ifdef WSAEWOULDBLOCK
 238 #   if WSAEWOULDBLOCK != EWOULDBLOCK
 239     case EWOULDBLOCK:
 240 #   endif
 241 #  else
 242     case EWOULDBLOCK:
 243 #  endif
 244 # endif
 245
 246 # if defined(ENOTCONN)
 247     case ENOTCONN:
 248 # endif
 249
 250 # ifdef EINTR
 251     case EINTR:
 252 # endif
 253
 254 # ifdef EAGAIN
 255 #  if EWOULDBLOCK != EAGAIN
 256     case EAGAIN:
 257 #  endif
 258 # endif
 259
 260 # ifdef EPROTO
 261     case EPROTO:
 262 # endif
 263
 264 # ifdef EINPROGRESS
 265     case EINPROGRESS:
 266 # endif
 267
 268 # ifdef EALREADY
 269     case EALREADY:
 270 # endif
 271         return (1);
 272     default:
 273         break;
 274     }
 275     return (0);
 276 }
 277 #endif