bio.c

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/*
     This file is part of GNUnet.
     Copyright (C) 2006, 2009, 2013 GNUnet e.V.
 
     GNUnet is free software: you can redistribute it and/or modify it
     under the terms of the GNU Affero General Public License as published
     by the Free Software Foundation, either version 3 of the License,
     or (at your option) any later version.
 
     GNUnet is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Affero General Public License for more details.
 
     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
     SPDX-License-Identifier: AGPL3.0-or-later
 */
#include "gnunet_common.h"
#include "platform.h"
#include "gnunet_util_lib.h"
 
#define LOG(kind, ...) GNUNET_log_from (kind, "util-bio", __VA_ARGS__)
 
#ifndef PATH_MAX
#define PATH_MAX 4096
#endif
 
 
#define BIO_BUFFER_SIZE 65536
 
 
enum IOType
{
  IO_FILE = 0,
 
  IO_BUFFER,
};
 
 
struct GNUNET_BIO_ReadHandle
{
  enum IOType type;
 
  struct GNUNET_DISK_FileHandle *fd;
 
  char *emsg;
 
  char *buffer;
 
  size_t have;
 
  size_t size;
 
  off_t pos;
};
 
 
struct GNUNET_BIO_ReadHandle *
GNUNET_BIO_read_open_file (const char *fn)
{
  struct GNUNET_DISK_FileHandle *fd;
  struct GNUNET_BIO_ReadHandle *h;
 
  fd = GNUNET_DISK_file_open (fn, GNUNET_DISK_OPEN_READ, GNUNET_DISK_PERM_NONE);
  if (NULL == fd)
    return NULL;
  h = GNUNET_malloc (sizeof(struct GNUNET_BIO_ReadHandle) + BIO_BUFFER_SIZE);
  h->type = IO_FILE;
  h->buffer = (char *) &h[1];
  h->size = BIO_BUFFER_SIZE;
  h->fd = fd;
  return h;
}
 
 
struct GNUNET_BIO_ReadHandle *
GNUNET_BIO_read_open_buffer (void *buffer, size_t size)
{
  struct GNUNET_BIO_ReadHandle *h;
 
  h = GNUNET_new (struct GNUNET_BIO_ReadHandle);
  h->type = IO_BUFFER;
  h->buffer = buffer;
  h->size = size;
  return h;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_read_close (struct GNUNET_BIO_ReadHandle *h, char **emsg)
{
  int err;
 
  err = (NULL == h->emsg) ? GNUNET_OK : GNUNET_SYSERR;
  if (NULL != emsg)
    *emsg = h->emsg;
  else
    GNUNET_free (h->emsg);
  switch (h->type)
  {
  case IO_FILE:
    GNUNET_DISK_file_close (h->fd);
    break;
  case IO_BUFFER:
    break;
  default:
    break;
  }
  GNUNET_free (h);
  return err;
}
 
 
void
GNUNET_BIO_read_set_error (struct GNUNET_BIO_ReadHandle *h, const char*emsg)
{
  GNUNET_assert (NULL == h->emsg);
  h->emsg = GNUNET_strdup (emsg);
}
 
 
static int
read_from_file (struct GNUNET_BIO_ReadHandle *h,
                const char *what,
                char *result,
                size_t len)
{
  size_t pos = 0;
  size_t min;
  ssize_t ret;
 
  do
  {
    min = h->have - h->pos;
    if (0 < min)
    {
      if (len - pos < min)
        min = len - pos;
      GNUNET_memcpy (&result[pos], &h->buffer[h->pos], min);
      h->pos += min;
      pos += min;
    }
    if (len == pos)
      return GNUNET_OK;
    GNUNET_assert (((off_t) h->have) == h->pos);
    ret = GNUNET_DISK_file_read (h->fd, h->buffer, h->size);
    if (-1 == ret)
    {
      GNUNET_asprintf (&h->emsg,
                       _ ("Error reading `%s' from file: %s"),
                       what,
                       strerror (errno));
      return GNUNET_SYSERR;
    }
    if (0 == ret)
    {
      GNUNET_asprintf (&h->emsg,
                       _ ("Error reading `%s' from file: %s"),
                       what,
                       _ ("End of file"));
      return GNUNET_SYSERR;
    }
    h->pos = 0;
    h->have = ret;
  }
  while (pos < len);
  return GNUNET_OK;
}
 
 
static int
read_from_buffer (struct GNUNET_BIO_ReadHandle *h,
                  const char *what,
                  char *result,
                  size_t len)
{
  if ((h->size < len) || (h->size - h->pos < len))
  {
    GNUNET_asprintf (&h->emsg,
                     _ ("Error while reading `%s' from buffer: %s"),
                     what,
                     _ ("Not enough data left"));
    return GNUNET_SYSERR;
  }
  GNUNET_memcpy (result, h->buffer + h->pos, len);
  h->pos += len;
  return GNUNET_OK;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_read (struct GNUNET_BIO_ReadHandle *h,
                 const char *what,
                 void *result,
                 size_t len)
{
  char *dst = result;
 
  if (NULL != h->emsg)
    return GNUNET_SYSERR;
 
  if (0 == len)
    return GNUNET_OK;
 
  switch (h->type)
  {
  case IO_FILE:
    return read_from_file (h, what, dst, len);
  case IO_BUFFER:
    return read_from_buffer (h, what, dst, len);
  default:
    GNUNET_asprintf (&h->emsg,
                     _ ("Invalid handle type while reading `%s'"),
                     what);
    return GNUNET_SYSERR;
  }
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_read_string (struct GNUNET_BIO_ReadHandle *h,
                        const char *what,
                        char **result,
                        size_t max_length)
{
  char *buf;
  uint32_t big;
 
  if (GNUNET_OK != GNUNET_BIO_read_int32 (h,
                                          _ ("string length"),
                                          (int32_t *) &big))
  {
    char *tmp = h->emsg;
    if (NULL != tmp)
      GNUNET_asprintf (&h->emsg,
                       _ ("%s (while reading `%s')"),
                       tmp,
                       what);
    else
      GNUNET_asprintf (&h->emsg,
                       _ ("Error reading length of string `%s'"),
                       what);
    GNUNET_free (tmp);
    return GNUNET_SYSERR;
  }
  if (0 == big)
  {
    *result = NULL;
    return GNUNET_OK;
  }
  if (big > max_length)
  {
    GNUNET_asprintf (&h->emsg,
                     _ ("String `%s' longer than allowed (%u > %lu)"),
                     what,
                     big,
                     (unsigned long) max_length);
    return GNUNET_SYSERR;
  }
  buf = GNUNET_malloc (big);
  *result = buf;
  buf[--big] = '\0';
  if (0 == big)
    return GNUNET_OK;
  if (GNUNET_OK != GNUNET_BIO_read (h, what, buf, big))
  {
    GNUNET_free (buf);
    *result = NULL;
    return GNUNET_SYSERR;
  }
  return GNUNET_OK;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_read_float (struct GNUNET_BIO_ReadHandle *h,
                       const char *what,
                       float *f)
{
  int32_t *i = (int32_t *) f;
  return GNUNET_BIO_read_int32 (h, what, i);
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_read_double (struct GNUNET_BIO_ReadHandle *h,
                        const char *what,
                        double *f)
{
  int64_t *i = (int64_t *) f;
  return GNUNET_BIO_read_int64 (h, what, i);
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_read_int32 (struct GNUNET_BIO_ReadHandle *h,
                       const char *what,
                       int32_t *i)
{
  int32_t big;
 
  if (GNUNET_OK != GNUNET_BIO_read (h, what, &big, sizeof(int32_t)))
    return GNUNET_SYSERR;
  *i = ntohl (big);
  return GNUNET_OK;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_read_int64 (struct GNUNET_BIO_ReadHandle *h,
                       const char *what,
                       int64_t *i)
{
  int64_t big;
 
  if (GNUNET_OK != GNUNET_BIO_read (h, what, &big, sizeof(int64_t)))
    return GNUNET_SYSERR;
  *i = GNUNET_ntohll (big);
  return GNUNET_OK;
}
 
 
struct GNUNET_BIO_WriteHandle
{
  enum IOType type;
 
  struct GNUNET_DISK_FileHandle *fd;
 
  char *emsg;
 
  void *buffer;
 
  size_t have;
 
  size_t size;
};
 
 
struct GNUNET_BIO_WriteHandle *
GNUNET_BIO_write_open_file (const char *fn)
{
  struct GNUNET_DISK_FileHandle *fd;
  struct GNUNET_BIO_WriteHandle *h;
 
  fd = GNUNET_DISK_file_open (fn,
                              GNUNET_DISK_OPEN_WRITE
                              | GNUNET_DISK_OPEN_TRUNCATE
                              | GNUNET_DISK_OPEN_CREATE,
                              GNUNET_DISK_PERM_USER_READ
                              | GNUNET_DISK_PERM_USER_WRITE);
  if (NULL == fd)
    return NULL;
  h = GNUNET_malloc (sizeof(struct GNUNET_BIO_WriteHandle) + BIO_BUFFER_SIZE);
  h->buffer = &h[1];
  h->size = BIO_BUFFER_SIZE;
  h->fd = fd;
  return h;
}
 
 
struct GNUNET_BIO_WriteHandle *
GNUNET_BIO_write_open_buffer (void)
{
  struct GNUNET_BIO_WriteHandle *h;
 
  h = GNUNET_new (struct GNUNET_BIO_WriteHandle);
  h->type = IO_BUFFER;
  h->buffer = (void *) GNUNET_malloc (sizeof (struct GNUNET_Buffer));
  return h;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_write_close (struct GNUNET_BIO_WriteHandle *h,
                        char **emsg)
{
  int err;
 
  err = (NULL == h->emsg) ? GNUNET_OK : GNUNET_SYSERR;
  if (NULL != emsg)
    *emsg = h->emsg;
  else
    GNUNET_free (h->emsg);
  switch (h->type)
  {
  case IO_FILE:
    if (NULL == h->fd)
    {
      err = GNUNET_SYSERR;
      break;
    }
    if (GNUNET_OK != GNUNET_BIO_flush (h))
    {
      if (NULL != emsg)
        *emsg = h->emsg;
      else
        GNUNET_free (h->emsg);
      err = GNUNET_SYSERR;
    }
    else
    {
      GNUNET_DISK_file_close (h->fd);
    }
    break;
  case IO_BUFFER:
    GNUNET_buffer_clear ((struct GNUNET_Buffer *) h->buffer);
    GNUNET_free (h->buffer);
    break;
  }
  GNUNET_free (h);
  return err;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_flush (struct GNUNET_BIO_WriteHandle *h)
{
  ssize_t ret;
 
  if (IO_FILE != h->type)
    return GNUNET_OK;
  ret = GNUNET_DISK_file_write (h->fd,
                                h->buffer,
                                h->have);
  if (ret != (ssize_t) h->have)
  {
    GNUNET_DISK_file_close (h->fd);
    h->fd = NULL;
    GNUNET_free (h->emsg);
    GNUNET_asprintf (&h->emsg,
                     "Unable to flush buffer to file");
    return GNUNET_SYSERR;
  }
  h->have = 0;
  return GNUNET_OK;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_get_buffer_contents (struct GNUNET_BIO_WriteHandle *h,
                                char **emsg,
                                void **contents,
                                size_t *size)
{
  if (IO_BUFFER != h->type)
    return GNUNET_SYSERR;
  if ((NULL == contents) || (NULL == size))
    return GNUNET_SYSERR;
  enum GNUNET_GenericReturnValue ret
    = (NULL != h->emsg)
    ? GNUNET_SYSERR
    : GNUNET_OK;
  if (NULL != emsg)
    *emsg = h->emsg;
  else
    GNUNET_free (h->emsg);
  *contents = GNUNET_buffer_reap ((struct GNUNET_Buffer *) h->buffer, size);
  return ret;
}
 
 
static enum GNUNET_GenericReturnValue
write_to_file (struct GNUNET_BIO_WriteHandle *h,
               const char *what,
               const char *source,
               size_t len)
{
  size_t min;
  size_t pos = 0;
  char *buffer = (char *) h->buffer;
 
  if (NULL == h->fd)
  {
    GNUNET_asprintf (&h->emsg,
                     _ ("Error while writing `%s' to file: %s"),
                     what,
                     _ ("No associated file"));
    return GNUNET_SYSERR;
  }
 
  do
  {
    min = h->size - h->have;
    if (len - pos < min)
      min = len - pos;
    GNUNET_memcpy (&buffer[h->have], &source[pos], min);
    pos += min;
    h->have += min;
    if (len == pos)
      return GNUNET_OK;
    GNUNET_assert (h->have == h->size);
    if (GNUNET_OK != GNUNET_BIO_flush (h))
    {
      char *tmp = h->emsg;
      GNUNET_asprintf (&h->emsg,
                       _ ("Error while writing `%s' to file: %s"),
                       what,
                       tmp);
      GNUNET_free (tmp);
      return GNUNET_SYSERR;
    }
  }
  while (pos < len);
  GNUNET_break (0);
  return GNUNET_OK;
}
 
 
static int
write_to_buffer (struct GNUNET_BIO_WriteHandle *h,
                 const char *what,
                 const char *source,
                 size_t len)
{
  GNUNET_buffer_write ((struct GNUNET_Buffer *) h->buffer, source, len);
  h->have += len;
  return GNUNET_OK;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_write (struct GNUNET_BIO_WriteHandle *h,
                  const char *what,
                  const void *buffer,
                  size_t n)
{
  const char *src = buffer;
 
  if (NULL != h->emsg)
    return GNUNET_SYSERR;
 
  if (0 == n)
    return GNUNET_OK;
 
  switch (h->type)
  {
  case IO_FILE:
    return write_to_file (h, what, src, n);
  case IO_BUFFER:
    return write_to_buffer (h, what, src, n);
  default:
    GNUNET_asprintf (&h->emsg,
                     _ ("Invalid handle type while writing `%s'"),
                     what);
    return GNUNET_SYSERR;
  }
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_write_string (struct GNUNET_BIO_WriteHandle *h,
                         const char *what,
                         const char *s)
{
  uint32_t slen;
 
  slen = (uint32_t) ((s == NULL) ? 0 : strlen (s) + 1);
  if (GNUNET_OK != GNUNET_BIO_write_int32 (h, _ ("string length"), slen))
    return GNUNET_SYSERR;
  if (0 != slen)
    return GNUNET_BIO_write (h, what, s, slen - 1);
  return GNUNET_OK;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_write_float (struct GNUNET_BIO_WriteHandle *h,
                        const char *what,
                        float f)
{
  int32_t i = f;
  return GNUNET_BIO_write_int32 (h, what, i);
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_write_double (struct GNUNET_BIO_WriteHandle *h,
                         const char *what,
                         double f)
{
  int64_t i = f;
  return GNUNET_BIO_write_int64 (h, what, i);
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_write_int32 (struct GNUNET_BIO_WriteHandle *h,
                        const char *what,
                        int32_t i)
{
  int32_t big;
 
  big = htonl (i);
  return GNUNET_BIO_write (h, what, &big, sizeof(int32_t));
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_write_int64 (struct GNUNET_BIO_WriteHandle *h,
                        const char *what,
                        int64_t i)
{
  int64_t big;
 
  big = GNUNET_htonll (i);
  return GNUNET_BIO_write (h, what, &big, sizeof(int64_t));
}
 
 
static int
read_spec_handler_object (void *cls,
                          struct GNUNET_BIO_ReadHandle *h,
                          const char *what,
                          void *target,
                          size_t target_size)
{
  return GNUNET_BIO_read (h, what, target, target_size);
}
 
 
struct GNUNET_BIO_ReadSpec
GNUNET_BIO_read_spec_object (const char *what,
                             void *result,
                             size_t len)
{
  struct GNUNET_BIO_ReadSpec rs = {
    .rh = &read_spec_handler_object,
    .cls = NULL,
    .what = what,
    .target = result,
    .size = len,
  };
 
  return rs;
}
 
 
static int
read_spec_handler_string (void *cls,
                          struct GNUNET_BIO_ReadHandle *h,
                          const char *what,
                          void *target,
                          size_t target_size)
{
  char **result = target;
  return GNUNET_BIO_read_string (h, what, result, target_size);
}
 
 
struct GNUNET_BIO_ReadSpec
GNUNET_BIO_read_spec_string (const char *what,
                             char **result,
                             size_t max_length)
{
  struct GNUNET_BIO_ReadSpec rs = {
    .rh = &read_spec_handler_string,
    .cls = NULL,
    .target = result,
    .size = max_length,
  };
 
  return rs;
}
 
 
static int
read_spec_handler_int32 (void *cls,
                         struct GNUNET_BIO_ReadHandle *h,
                         const char *what,
                         void *target,
                         size_t target_size)
{
  int32_t *result = target;
  return GNUNET_BIO_read_int32 (h, what, result);
}
 
 
struct GNUNET_BIO_ReadSpec
GNUNET_BIO_read_spec_int32 (const char *what,
                            int32_t *i)
{
  struct GNUNET_BIO_ReadSpec rs = {
    .rh = &read_spec_handler_int32,
    .cls = NULL,
    .target = i,
    .size = 0,
  };
 
  return rs;
}
 
 
static int
read_spec_handler_int64 (void *cls,
                         struct GNUNET_BIO_ReadHandle *h,
                         const char *what,
                         void *target,
                         size_t target_size)
{
  int64_t *result = target;
  return GNUNET_BIO_read_int64 (h, what, result);
}
 
 
struct GNUNET_BIO_ReadSpec
GNUNET_BIO_read_spec_int64 (const char *what,
                            int64_t *i)
{
  struct GNUNET_BIO_ReadSpec rs = {
    .rh = &read_spec_handler_int64,
    .cls = NULL,
    .target = i,
    .size = 0,
  };
 
  return rs;
}
 
 
struct GNUNET_BIO_ReadSpec
GNUNET_BIO_read_spec_float (const char *what, float *f)
{
  struct GNUNET_BIO_ReadSpec rs = {
    .rh = &read_spec_handler_int32,
    .cls = NULL,
    .target = (int32_t *) f,
    .size = 0,
  };
 
  return rs;
}
 
 
struct GNUNET_BIO_ReadSpec
GNUNET_BIO_read_spec_double (const char *what, double *f)
{
  struct GNUNET_BIO_ReadSpec rs = {
    .rh = &read_spec_handler_int64,
    .cls = NULL,
    .target = (int64_t *) f,
    .size = 0,
  };
 
  return rs;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_read_spec_commit (struct GNUNET_BIO_ReadHandle *h,
                             struct GNUNET_BIO_ReadSpec *rs)
{
  int ret = GNUNET_OK;
 
  for (size_t i = 0; NULL!=rs[i].rh; ++i)
  {
    ret = rs[i].rh (rs[i].cls, h, rs[i].what, rs[i].target, rs[i].size);
    if (GNUNET_OK != ret)
      return ret;
  }
 
  return ret;
}
 
 
static int
write_spec_handler_object (void *cls,
                           struct GNUNET_BIO_WriteHandle *h,
                           const char *what,
                           void *source,
                           size_t source_size)
{
  return GNUNET_BIO_write (h, what, source, source_size);
}
 
 
struct GNUNET_BIO_WriteSpec
GNUNET_BIO_write_spec_object (const char *what,
                              void *source,
                              size_t size)
{
  struct GNUNET_BIO_WriteSpec ws = {
    .wh = &write_spec_handler_object,
    .cls = NULL,
    .what = what,
    .source = source,
    .source_size = size,
  };
 
  return ws;
}
 
 
static int
write_spec_handler_string (void *cls,
                           struct GNUNET_BIO_WriteHandle *h,
                           const char *what,
                           void *source,
                           size_t source_size)
{
  const char *s = source;
  return GNUNET_BIO_write_string (h, what, s);
}
 
 
struct GNUNET_BIO_WriteSpec
GNUNET_BIO_write_spec_string (const char *what,
                              const char *s)
{
  struct GNUNET_BIO_WriteSpec ws = {
    .wh = &write_spec_handler_string,
    .cls = NULL,
    .what = what,
    .source = (void *) s,
    .source_size = 0,
  };
 
  return ws;
}
 
 
static int
write_spec_handler_int32 (void *cls,
                          struct GNUNET_BIO_WriteHandle *h,
                          const char *what,
                          void *source,
                          size_t source_size)
{
  int32_t i = *(int32_t *) source;
  return GNUNET_BIO_write_int32 (h, what, i);
}
 
 
struct GNUNET_BIO_WriteSpec
GNUNET_BIO_write_spec_int32 (const char *what,
                             int32_t *i)
{
  struct GNUNET_BIO_WriteSpec ws = {
    .wh = &write_spec_handler_int32,
    .cls = NULL,
    .what = what,
    .source = i,
    .source_size = 0,
  };
 
  return ws;
}
 
 
static int
write_spec_handler_int64 (void *cls,
                          struct GNUNET_BIO_WriteHandle *h,
                          const char *what,
                          void *source,
                          size_t source_size)
{
  int64_t i = *(int64_t *) source;
  return GNUNET_BIO_write_int64 (h, what, i);
}
 
 
struct GNUNET_BIO_WriteSpec
GNUNET_BIO_write_spec_int64 (const char *what,
                             int64_t *i)
{
  struct GNUNET_BIO_WriteSpec ws = {
    .wh = &write_spec_handler_int64,
    .cls = NULL,
    .what = what,
    .source = i,
    .source_size = 0,
  };
 
  return ws;
}
 
 
struct GNUNET_BIO_WriteSpec
GNUNET_BIO_write_spec_float (const char *what, float *f)
{
  struct GNUNET_BIO_WriteSpec ws = {
    .wh = &write_spec_handler_int32,
    .cls = NULL,
    .what = what,
    .source = (int32_t *) f,
    .source_size = 0,
  };
 
  return ws;
}
 
 
struct GNUNET_BIO_WriteSpec
GNUNET_BIO_write_spec_double (const char *what, double *f)
{
  struct GNUNET_BIO_WriteSpec ws = {
    .wh = &write_spec_handler_int64,
    .cls = NULL,
    .what = what,
    .source = (int64_t *) f,
    .source_size = 0,
  };
 
  return ws;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_BIO_write_spec_commit (struct GNUNET_BIO_WriteHandle *h,
                              struct GNUNET_BIO_WriteSpec *ws)
{
  int ret = GNUNET_OK;
 
  for (size_t i = 0; NULL!=ws[i].wh; ++i)
  {
    ret = ws[i].wh (ws[i].cls, h, ws[i].what, ws[i].source, ws[i].source_size);
    if (GNUNET_OK != ret)
      return ret;
  }
 
  /* If it's a file-based handle, the flush makes sure that the data in the
     buffer is actually written to the disk. */
  if (IO_FILE == h->type)
    ret = GNUNET_BIO_flush (h);
 
  return ret;
}
 
 
/* end of bio.c */