/* * Copyright (c) 2013-2014 Todd C. Miller <Todd.Miller@courtesan.com> * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include <config.h> #include <sys/types.h> #include <errno.h> #include <limits.h> #if defined(HAVE_STDINT_H) # include <stdint.h> #elif defined(HAVE_INTTYPES_H) # include <inttypes.h> #endif #include "sudo_compat.h" #ifndef RSIZE_MAX # if defined(SIZE_MAX) # define RSIZE_MAX (SIZE_MAX >> 1) # elif defined(__LP64__) # define RSIZE_MAX 0x7fffffffffffffffUL # else # define RSIZE_MAX 0x7fffffffU # endif #endif /* * Simple implementation of C11 memset_s() function. * We use a volatile pointer when updating the byte string. * Most compilers will avoid optimizing away access to a * volatile pointer, even if the pointer appears to be unused * after the call. * * Note that C11 does not specify the return value on error, only * that it be non-zero. We use EINVAL for all errors. */ errno_t sudo_memset_s(void *v, rsize_t smax, int c, rsize_t n) { errno_t ret = 0; volatile unsigned char *s = v; /* Fatal runtime-constraint violations. */ if (s == NULL || smax > RSIZE_MAX) { ret = errno = EINVAL; goto done; } /* Non-fatal runtime-constraint violation, n must not exceed smax. */ if (n > smax) { n = smax; ret = errno = EINVAL; } /* Updating through a volatile pointer should not be optimized away. */ while (n--) *s++ = (unsigned char)c; done: return ret; }