/*------------------------------------------------------------------ * * Module: strlcpy.c * * Purpose: Safe string functions to guard against buffer overflow. * * Description: The size of character strings, especially when coming from the * outside, can sometimes exceed a fixed size storage area. * * There was one case where a MIC-E format packet had an enormous * comment that exceeded an internal buffer of 256 characters, * resulting in a crash. * * We are not always meticulous about checking sizes to avoid overflow. * Use of these functions, instead of strcpy and strcat, should * help avoid issues. * * Orgin: From OpenBSD as the copyright notice indicates. * The GNU folks didn't think it was appropriate for inclusion * in glibc. https://lwn.net/Articles/507319/ * * Modifications: Added extra debug output when strings are truncated. * Not sure if I will leave this in the release version * or just let it happen silently. * *---------------------------------------------------------------*/ /* $NetBSD: strlcpy.c,v 1.5 2014/10/31 18:59:32 spz Exp $ */ /* from NetBSD: strlcpy.c,v 1.14 2003/10/27 00:12:42 lukem Exp */ /* from OpenBSD: strlcpy.c,v 1.7 2003/04/12 21:56:39 millert Exp */ /* * Copyright (c) 1998 Todd C. Miller * * 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 TODD C. MILLER DISCLAIMS ALL * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL TODD C. MILLER 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 "direwolf.h" #include #include #include //#include "textcolor.h" /* * Copy src to string dst of size siz. At most siz-1 characters * will be copied. Always NUL terminates (unless siz == 0). * Returns strlen(src); if retval >= siz, truncation occurred. */ #if DEBUG_STRL size_t strlcpy_debug(char *__restrict__ dst, const char *__restrict__ src, size_t siz, const char *file, const char *func, int line) #else size_t strlcpy_debug(char *__restrict__ dst, const char *__restrict__ src, size_t siz) #endif { char *d = dst; const char *s = src; size_t n = siz; size_t retval; #if DEBUG_STRL if (dst == NULL) { //text_color_set (DW_COLOR_ERROR); printf ("ERROR: strlcpy dst is NULL. (%s %s %d)\n", file, func, line); return (0); } if (src == NULL) { //text_color_set (DW_COLOR_ERROR); printf ("ERROR: strlcpy src is NULL. (%s %s %d)\n", file, func, line); return (0); } if (siz == 1 || siz == 4) { //text_color_set (DW_COLOR_ERROR); printf ("Suspicious strlcpy siz. Is it using sizeof a pointer variable? (%s %s %d)\n", file, func, line); } #endif /* Copy as many bytes as will fit */ if (n != 0 && --n != 0) { do { if ((*d++ = *s++) == 0) break; } while (--n != 0); } /* Not enough room in dst, add NUL and traverse rest of src */ if (n == 0) { if (siz != 0) *d = '\0'; /* NUL-terminate dst */ while (*s++) ; } retval = s - src - 1; /* count does not include NUL */ #if DEBUG_STRL if (retval >= siz) { //text_color_set (DW_COLOR_ERROR); printf ("WARNING: strlcpy result length %d exceeds maximum length %d. (%s %s %d)\n", (int)retval, (int)(siz-1), file, func, line); } #endif return (retval); }