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Diffstat (limited to 'lib/util/string_wrappers.h')
-rw-r--r-- | lib/util/string_wrappers.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/lib/util/string_wrappers.h b/lib/util/string_wrappers.h new file mode 100644 index 0000000000..31d0a92252 --- /dev/null +++ b/lib/util/string_wrappers.h @@ -0,0 +1,132 @@ +/* + Unix SMB/CIFS implementation. + + string wrappers, for checking string sizes + + Copyright (C) Andrew Tridgell 1994-2011 + Copyright (C) Andrew Bartlett <abartlet@samba.org> 2003 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#ifndef _STRING_WRAPPERS_H +#define _STRING_WRAPPERS_H + +/* We need a number of different prototypes for our + non-existant fuctions */ +char * __unsafe_string_function_usage_here__(void); + +size_t __unsafe_string_function_usage_here_size_t__(void); + +size_t __unsafe_string_function_usage_here_char__(void); + +#ifdef HAVE_COMPILER_WILL_OPTIMIZE_OUT_FNS + +/* if the compiler will optimize out function calls, then use this to tell if we are + have the correct types (this works only where sizeof() returns the size of the buffer, not + the size of the pointer). */ + +#define CHECK_STRING_SIZE(d, len) (sizeof(d) != (len) && sizeof(d) != sizeof(char *)) + +#else /* HAVE_COMPILER_WILL_OPTIMIZE_OUT_FNS */ + +#endif /* HAVE_COMPILER_WILL_OPTIMIZE_OUT_FNS */ + +#define safe_strcpy_base(dest, src, base, size) \ + safe_strcpy(dest, src, size-PTR_DIFF(dest,base)-1) + +/* String copy functions - macro hell below adds 'type checking' (limited, + but the best we can do in C) */ + +#define fstrcpy(d,s) safe_strcpy((d),(s),sizeof(fstring)-1) +#define fstrcat(d,s) safe_strcat((d),(s),sizeof(fstring)-1) +#define nstrcpy(d,s) safe_strcpy((d), (s),sizeof(nstring)-1) +#define unstrcpy(d,s) safe_strcpy((d), (s),sizeof(unstring)-1) + +/* the addition of the DEVELOPER checks in safe_strcpy means we must + * update a lot of code. To make this a little easier here are some + * functions that provide the lengths with less pain */ + +/* overmalloc_safe_strcpy: DEPRECATED! Used when you know the + * destination buffer is longer than maxlength, but you don't know how + * long. This is not a good situation, because we can't do the normal + * sanity checks. Don't use in new code! */ + +#define overmalloc_safe_strcpy(dest,src,maxlength) \ + safe_strcpy_fn(dest,src,maxlength) + +#ifdef HAVE_COMPILER_WILL_OPTIMIZE_OUT_FNS + +/* if the compiler will optimize out function calls, then use this to tell if we are + have the correct types (this works only where sizeof() returns the size of the buffer, not + the size of the pointer). */ + +#define safe_strcpy(d, s, max_len) \ + (CHECK_STRING_SIZE(d, max_len+1) \ + ? __unsafe_string_function_usage_here__() \ + : safe_strcpy_fn((d), (s), (max_len))) + +#define safe_strcat(d, s, max_len) \ + (CHECK_STRING_SIZE(d, max_len+1) \ + ? __unsafe_string_function_usage_here__() \ + : safe_strcat_fn((d), (s), (max_len))) + +#define push_string_check(dest, src, dest_len, flags) \ + (CHECK_STRING_SIZE(dest, dest_len) \ + ? __unsafe_string_function_usage_here_size_t__() \ + : push_string_check_fn(dest, src, dest_len, flags)) + +#define pull_string_talloc(ctx, base_ptr, smb_flags2, dest, src, src_len, flags) \ + pull_string_talloc_fn(ctx, base_ptr, smb_flags2, dest, src, src_len, flags) + +#define clistr_push(cli, dest, src, dest_len, flags) \ + (CHECK_STRING_SIZE(dest, dest_len) \ + ? __unsafe_string_function_usage_here_size_t__() \ + : clistr_push_fn(cli, dest, src, dest_len, flags)) + +#define clistr_pull(inbuf, dest, src, dest_len, srclen, flags) \ + (CHECK_STRING_SIZE(dest, dest_len) \ + ? __unsafe_string_function_usage_here_size_t__() \ + : clistr_pull_fn(inbuf, dest, src, dest_len, srclen, flags)) + +#define srvstr_push(base_ptr, smb_flags2, dest, src, dest_len, flags) \ + (CHECK_STRING_SIZE(dest, dest_len) \ + ? __unsafe_string_function_usage_here_size_t__() \ + : srvstr_push_fn(base_ptr, smb_flags2, dest, src, dest_len, flags)) + +/* This allows the developer to choose to check the arguments to + strlcpy. if the compiler will optimize out function calls, then + use this to tell if we are have the correct size buffer (this works only + where sizeof() returns the size of the buffer, not the size of the + pointer), so stack and static variables only */ + +#define checked_strlcpy(dest, src, size) \ + (sizeof(dest) != (size) \ + ? __unsafe_string_function_usage_here_size_t__() \ + : strlcpy(dest, src, size)) + +#else + +#define safe_strcpy safe_strcpy_fn +#define safe_strcat safe_strcat_fn +#define push_string_check push_string_check_fn +#define pull_string_talloc pull_string_talloc_fn +#define clistr_push clistr_push_fn +#define clistr_pull clistr_pull_fn +#define srvstr_push srvstr_push_fn +#define checked_strlcpy strlcpy + +#endif + +#endif |