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,
  62     "file descriptor",
  63     /* TODO: Convert to new style write function */
  64     bwrite_conv,
  65     fd_write,
  66     /* TODO: Convert to new style read function */
  67     bread_conv,
  68     fd_read,
  69     fd_puts,
  70     fd_gets,
  71     fd_ctrl,
  72     fd_new,
  73     fd_free,
  74     NULL,
  75 };
  76
  77 const BIO_METHOD *BIO_s_fd(void)
  78 {
  79     return &methods_fdp;
  80 }
  81
  82 BIO *BIO_new_fd(int fd, int close_flag)
  83 {
  84     BIO *ret;
  85     ret = BIO_new(BIO_s_fd());
  86     if (ret == NULL)
  87         return NULL;
  88     BIO_set_fd(ret, fd, close_flag);
  89     return ret;
  90 }
  91
  92 static int fd_new(BIO *bi)
  93 {
  94     bi->init = 0;
  95     bi->num = -1;
  96     bi->ptr = NULL;
  97     bi->flags = BIO_FLAGS_UPLINK; /* essentially redundant */
  98     return 1;
  99 }
 100
 101 static int fd_free(BIO *a)
 102 {
 103     if (a == NULL)
 104         return 0;
 105     if (a->shutdown) {
 106         if (a->init) {
 107             UP_close(a->num);
 108         }
 109         a->init = 0;
 110         a->flags = BIO_FLAGS_UPLINK;
 111     }
 112     return 1;
 113 }
 114
 115 static int fd_read(BIO *b, char *out, int outl)
 116 {
 117     int ret = 0;
 118
 119     if (out != NULL) {
 120         clear_sys_error();
 121         ret = UP_read(b->num, out, outl);
 122         BIO_clear_retry_flags(b);
 123         if (ret <= 0) {
 124             if (BIO_fd_should_retry(ret))
 125                 BIO_set_retry_read(b);
 126         }
 127     }
 128     return ret;
 129 }
 130
 131 static int fd_write(BIO *b, const char *in, int inl)
 132 {
 133     int ret;
 134     clear_sys_error();
 135     ret = UP_write(b->num, in, inl);
 136     BIO_clear_retry_flags(b);
 137     if (ret <= 0) {
 138         if (BIO_fd_should_retry(ret))
 139             BIO_set_retry_write(b);
 140     }
 141     return ret;
 142 }
 143
 144 static long fd_ctrl(BIO *b, int cmd, long num, void *ptr)
 145 {
 146     long ret = 1;
 147     int *ip;
 148
 149     switch (cmd) {
 150     case BIO_CTRL_RESET:
 151         num = 0;
 152         /* fall thru */
 153     case BIO_C_FILE_SEEK:
 154         ret = (long)UP_lseek(b->num, num, 0);
 155         break;
 156     case BIO_C_FILE_TELL:
 157     case BIO_CTRL_INFO:
 158         ret = (long)UP_lseek(b->num, 0, 1);
 159         break;
 160     case BIO_C_SET_FD:
 161         fd_free(b);
 162         b->num = *((int *)ptr);
 163         b->shutdown = (int)num;
 164         b->init = 1;
 165         break;
 166     case BIO_C_GET_FD:
 167         if (b->init) {
 168             ip = (int *)ptr;
 169             if (ip != NULL)
 170                 *ip = b->num;
 171             ret = b->num;
 172         } else
 173             ret = -1;
 174         break;
 175     case BIO_CTRL_GET_CLOSE:
 176         ret = b->shutdown;
 177         break;
 178     case BIO_CTRL_SET_CLOSE:
 179         b->shutdown = (int)num;
 180         break;
 181     case BIO_CTRL_PENDING:
 182     case BIO_CTRL_WPENDING:
 183         ret = 0;
 184         break;
 185     case BIO_CTRL_DUP:
 186     case BIO_CTRL_FLUSH:
 187         ret = 1;
 188         break;
 189     default:
 190         ret = 0;
 191         break;
 192     }
 193     return ret;
 194 }
 195
 196 static int fd_puts(BIO *bp, const char *str)
 197 {
 198     int n, ret;
 199
 200     n = strlen(str);
 201     ret = fd_write(bp, str, n);
 202     return ret;
 203 }
 204
 205 static int fd_gets(BIO *bp, char *buf, int size)
 206 {
 207     int ret = 0;
 208     char *ptr = buf;
 209     char *end = buf + size - 1;
 210
 211     while (ptr < end && fd_read(bp, ptr, 1) > 0) {
 212         if (*ptr++ == '\n')
 213            break;
 214     }
 215
 216     ptr[0] = '\0';
 217
 218     if (buf[0] != '\0')
 219         ret = strlen(buf);
 220     return ret;
 221 }
 222
 223 int BIO_fd_should_retry(int i)
 224 {
 225     int err;
 226
 227     if ((i == 0) || (i == -1)) {
 228         err = get_last_sys_error();
 229
 230         return BIO_fd_non_fatal_error(err);
 231     }
 232     return 0;
 233 }
 234
 235 int BIO_fd_non_fatal_error(int err)
 236 {
 237     switch (err) {
 238
 239 # ifdef EWOULDBLOCK
 240 #  ifdef WSAEWOULDBLOCK
 241 #   if WSAEWOULDBLOCK != EWOULDBLOCK
 242     case EWOULDBLOCK:
 243 #   endif
 244 #  else
 245     case EWOULDBLOCK:
 246 #  endif
 247 # endif
 248
 249 # if defined(ENOTCONN)
 250     case ENOTCONN:
 251 # endif
 252
 253 # ifdef EINTR
 254     case EINTR:
 255 # endif
 256
 257 # ifdef EAGAIN
 258 #  if EWOULDBLOCK != EAGAIN
 259     case EAGAIN:
 260 #  endif
 261 # endif
 262
 263 # ifdef EPROTO
 264     case EPROTO:
 265 # endif
 266
 267 # ifdef EINPROGRESS
 268     case EINPROGRESS:
 269 # endif
 270
 271 # ifdef EALREADY
 272     case EALREADY:
 273 # endif
 274         return 1;
 275     default:
 276         break;
 277     }
 278     return 0;
 279 }
 280 #endif