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Diffstat (limited to 'erts/etc/unix/safe_string.c')
-rw-r--r-- | erts/etc/unix/safe_string.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/erts/etc/unix/safe_string.c b/erts/etc/unix/safe_string.c new file mode 100644 index 0000000000..a77d9c5456 --- /dev/null +++ b/erts/etc/unix/safe_string.c @@ -0,0 +1,123 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2008-2009. All Rights Reserved. + * + * The contents of this file are subject to the Erlang Public License, + * Version 1.1, (the "License"); you may not use this file except in + * compliance with the License. You should have received a copy of the + * Erlang Public License along with this software. If not, it can be + * retrieved online at http://www.erlang.org/. + * + * Software distributed under the License is distributed on an "AS IS" + * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + * the License for the specific language governing rights and limitations + * under the License. + * + * %CopyrightEnd% + */ +/* + * Module: safe_string.c + * + * This is a bunch of generic string operation + * that are safe regarding buffer overflow. + * + * All string functions terminate the process with an error message + * on buffer overflow. + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif +#include "safe_string.h" +#include <stdio.h> +#include <string.h> +#include <stdarg.h> +#include <stdlib.h> + + +static void string_overflow_handler(const char* format, ...) +{ + va_list args; + va_start(args, format); + vfprintf(stderr,format,args); + va_end(args); + exit(1); +} + +int vsn_printf(char* dst, size_t size, const char* format, va_list args) +{ + int ret = vsnprintf(dst, size, format, args); + if (ret >= size || ret < 0) { + string_overflow_handler("Buffer truncated '%s'\n",dst); + } + return ret; +} + +int sn_printf(char* dst, size_t size, const char* format, ...) +{ + va_list args; + int ret; + va_start(args, format); + ret = vsn_printf(dst,size,format,args); + va_end(args); + return ret; +} + +int strn_cpy(char* dst, size_t size, const char* src) +{ + return sn_printf(dst,size,"%s",src); +} + +int strn_cat(char* dst, size_t size, const char* src) +{ + return strn_catf(dst,size,"%s",src); +} + +int strn_catf(char* dst, size_t size, const char* format, ...) +{ + int ret; + va_list args; +#ifdef _GNU_SOURCE + int len = strnlen(dst,size); +#else + int len = strlen(dst); +#endif + + if (len >= size) { + string_overflow_handler("Buffer already overflowed '%.*s'\n", + size, dst); + } + va_start(args, format); + ret = vsn_printf(dst+len, size-len, format, args); + va_end(args); + return len+ret; +} + +char* find_str(const char* haystack, int hsize, const char* needle) +{ + int i = 0; + int nsize = strlen(needle); + hsize -= nsize - 1; + for (i=0; i<hsize; i++) { + if (haystack[i]==needle[0] && strncmp(haystack+i,needle,nsize)==0) { + return (char*)(haystack+i); + } + } + return NULL; +} + +#ifndef HAVE_MEMMOVE +void* memmove(void *dest, const void *src, size_t n) +{ + int i; + if (src > dest) { + for (i=0; i<n; i++) ((char*)dest)[i] = ((char*)src)[i]; + } + else { + for (i=(int)(n-1); i>=0; i--) ((char*)dest)[i] = ((char*)src)[i]; + } + return dest; +} +#endif /* HAVE_MEMMOVE */ + |