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Diffstat (limited to 'libelftc/elftc_copyfile.c')
| -rw-r--r-- | libelftc/elftc_copyfile.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/libelftc/elftc_copyfile.c b/libelftc/elftc_copyfile.c new file mode 100644 index 000000000000..0bacaf45e769 --- /dev/null +++ b/libelftc/elftc_copyfile.c @@ -0,0 +1,107 @@ +/*- + * Copyright (c) 2011, Joseph Koshy + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer + * in this position and unchanged. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/types.h> +#include <sys/stat.h> + +#include <stdlib.h> +#include <unistd.h> + +#include "libelftc.h" +#include "_libelftc.h" + +#if ELFTC_HAVE_MMAP +#include <sys/mman.h> +#endif + +ELFTC_VCSID("$Id: elftc_copyfile.c 2318 2011-12-11 10:54:27Z jkoshy $"); + +/* + * Copy the contents referenced by 'ifd' to 'ofd'. Returns 0 on + * success and -1 on error. + */ + +int +elftc_copyfile(int ifd, int ofd) +{ + int buf_mmapped; + struct stat sb; + char *b, *buf; + ssize_t nw; + size_t n; + + /* Determine the input file's size. */ + if (fstat(ifd, &sb) < 0) + return (-1); + + /* Skip files without content. */ + if (sb.st_size == 0) + return (0); + + buf = NULL; + buf_mmapped = 0; + +#if ELFTC_HAVE_MMAP + /* + * Prefer mmap() if it is available. + */ + buf = mmap(NULL, sb.st_size, PROT_READ, MAP_SHARED, ifd, (off_t) 0); + if (buf != MAP_FAILED) + buf_mmapped = 1; + else + buf = NULL; +#endif + + /* + * If mmap() is not available, or if the mmap() operation + * failed, allocate a buffer, and read in input data. + */ + if (buf == NULL) { + if ((buf = malloc(sb.st_size)) == NULL) + return (-1); + if (read(ifd, buf, sb.st_size) != sb.st_size) + return (-1); + } + + /* + * Write data to the output file descriptor. + */ + for (n = sb.st_size, b = buf; n > 0; n -= nw, b += nw) + if ((nw = write(ofd, b, n)) <= 0) + break; + + /* Release the input buffer. */ +#if ELFTC_HAVE_MMAP + if (buf_mmapped && munmap(buf, sb.st_size) < 0) + return (-1); +#endif + + if (!buf_mmapped) + free(buf); + + return (n > 0 ? -1 : 0); +} + |