Commit 99d72f72 authored by Nick Mathewson's avatar Nick Mathewson 🤹
Browse files

r16100@catbus: nickm | 2007-10-24 11:33:52 -0400 

 Make tor_mmap_file() set and preserve errno in a useful way.


svn:r12153
parent ab3fddd1

src/common/compat.c

+15 −1
Original line number Diff line number Diff line
@@ -126,7 +126,8 @@ typedef struct tor_mmap_impl_t { 
                        * size, rounded up to the nearest page.) */

} tor_mmap_impl_t;

/** Try to create a memory mapping for <b>filename</b> and return it.  On

 * failure, return NULL. */

 * failure, return NULL.  Sets errno properly, using ERANGE to mean

 * "empty file". */

tor_mmap_t *

tor_mmap_file(const char *filename)

{
@@ -140,9 +141,11 @@ tor_mmap_file(const char *filename) 


  fd = open(filename, O_RDONLY, 0);

  if (fd<0) {

    int save_errno = errno;

    int severity = (errno == ENOENT) ? LOG_INFO : LOG_WARN;

    log_fn(severity, LD_FS,"Could not open \"%s\" for mmap(): %s",filename,

           strerror(errno));

    errno = save_errno;

    return NULL;

  }
@@ -156,14 +159,17 @@ tor_mmap_file(const char *filename) 
    /* Zero-length file. If we call mmap on it, it will succeed but

     * return NULL, and bad things will happen. So just fail. */

    log_info(LD_FS,"File \"%s\" is empty. Ignoring.",filename);

    errno = ERANGE;

    return NULL;

  }



  string = mmap(0, size, PROT_READ, MAP_PRIVATE, fd, 0);

  if (string == MAP_FAILED) {

    int save_errno = errno;

    close(fd);

    log_warn(LD_FS,"Could not mmap file \"%s\": %s", filename,

             strerror(errno));

    errno = save_errno;

    return NULL;

  }
@@ -196,6 +202,7 @@ tor_mmap_t * 
tor_mmap_file(const char *filename)

{

  win_mmap_t *res = tor_malloc_zero(sizeof(win_mmap_t));

  int empty = 0;

  res->file_handle = INVALID_HANDLE_VALUE;

  res->mmap_handle = NULL;
@@ -213,6 +220,7 @@ tor_mmap_file(const char *filename) 


  if (res->base.size == 0) {

    log_info(LD_FS,"File \"%s\" is empty. Ignoring.",filename);

    empty = 1;

    goto err;

  }
@@ -243,7 +251,13 @@ tor_mmap_file(const char *filename) 
    log_fn(severity, LD_FS, "Couldn't mmap file \"%s\": %s", filename, msg);

    tor_free(msg);

  }

  if (e == ERROR_FILE_NOT_FOUND || e == ERROR_PATH_NOT_FOUND)

    e = ENOENT;

  else

    e = EINVAL;

 err:

  if (empty)

    errno = ERANGE;

  tor_munmap_file(&res->base);

  return NULL;

}

src/common/util.c

+8 −0
Original line number Diff line number Diff line
@@ -1782,16 +1782,20 @@ read_file_to_str(const char *filename, int flags, struct stat *stat_out) 
  fd = open(filename,O_RDONLY|(bin?O_BINARY:O_TEXT),0);

  if (fd<0) {

    int severity = LOG_WARN;

    int save_errno = errno;

    if (errno == ENOENT && (flags & RFTS_IGNORE_MISSING))

      severity = LOG_INFO;

    log_fn(severity, LD_FS,"Could not open \"%s\": %s ",filename,

           strerror(errno));

    errno = save_errno;

    return NULL;

  }



  if (fstat(fd, &statbuf)<0) {

    int save_errno = errno;

    close(fd);

    log_warn(LD_FS,"Could not fstat \"%s\".",filename);

    errno = save_errno;

    return NULL;

  }
@@ -1802,10 +1806,12 @@ read_file_to_str(const char *filename, int flags, struct stat *stat_out) 


  r = read_all(fd,string,(size_t)statbuf.st_size,0);

  if (r<0) {

    int save_errno = errno;

    log_warn(LD_FS,"Error reading from file \"%s\": %s", filename,

             strerror(errno));

    tor_free(string);

    close(fd);

    errno = save_errno;

    return NULL;

  }

  string[r] = '\0'; /* NUL-terminate the result. */
@@ -1825,10 +1831,12 @@ read_file_to_str(const char *filename, int flags, struct stat *stat_out) 
    if (r != statbuf.st_size) {

      /* Unless we're using text mode on win32, we'd better have an exact

       * match for size. */

      int save_errno = errno;

      log_warn(LD_FS,"Could read only %d of %ld bytes of file \"%s\".",

               r, (long)statbuf.st_size,filename);

      tor_free(string);

      close(fd);

      errno = save_errno;

      return NULL;

    }

  close(fd);