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Diffstat (limited to 'lib/strlcpy.c')
-rw-r--r-- | lib/strlcpy.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/lib/strlcpy.c b/lib/strlcpy.c new file mode 100644 index 0000000..71ee9f1 --- /dev/null +++ b/lib/strlcpy.c @@ -0,0 +1,58 @@ +/* Copy a null-terminated string to a fixed-size buffer, with length checking. + * Copyright (C) 2016 Free Software Foundation, Inc. + * This file is part of the GNU C Library. + * + * The GNU C Library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * The GNU C Library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with the GNU C Library; if not, see + * <http://www.gnu.org/licenses/>. + */ + +/* adapted for Quagga from glibc patch submission originally from + * Florian Weimer <fweimer@redhat.com>, 2016-05-18 */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <string.h> + +#ifndef HAVE_STRLCPY +#undef strlcpy + +size_t strlcpy(char *__restrict dest, + const char *__restrict src, size_t destsize); + +size_t strlcpy(char *__restrict dest, + const char *__restrict src, size_t destsize) +{ + size_t src_length = strlen(src); + + if (__builtin_expect(src_length >= destsize, 0)) { + if (destsize > 0) { + /* + * Copy the leading portion of the string. The last + * character is subsequently overwritten with the NUL + * terminator, but the destination destsize is usually + * a multiple of a small power of two, so writing it + * twice should be more efficient than copying an odd + * number of bytes. + */ + memcpy(dest, src, destsize); + dest[destsize - 1] = '\0'; + } + } else + /* Copy the string and its terminating NUL character. */ + memcpy(dest, src, src_length + 1); + return src_length; +} +#endif /* HAVE_STRLCPY */ |