taint enforce: file access backstops
[exim.git] / src / src / mytypes.h
... / ...
CommitLineData
1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
5/* Copyright (c) University of Cambridge 1995 - 2018 */
6/* See the file NOTICE for conditions of use and distribution. */
7
8
9/* This header file contains type definitions and macros that I use as
10"standard" in the code of Exim and its utilities. Make it idempotent because
11local_scan.h includes it and exim.h includes them both (to get this earlier). */
12
13#ifndef MYTYPES_H
14#define MYTYPES_H
15
16# include <string.h>
17
18#ifndef FALSE
19# define FALSE 0
20#endif
21
22#ifndef TRUE
23# define TRUE 1
24#endif
25
26#ifndef TRUE_UNSET
27# define TRUE_UNSET 2
28#endif
29
30
31/* If gcc is being used to compile Exim, we can use its facility for checking
32the arguments of printf-like functions. This is done by a macro. */
33
34#if defined(__GNUC__) || defined(__clang__)
35# define PRINTF_FUNCTION(A,B) __attribute__((format(printf,A,B)))
36# define ARG_UNUSED __attribute__((__unused__))
37# define WARN_UNUSED_RESULT __attribute__((__warn_unused_result__))
38# define ALLOC __attribute__((malloc))
39# define ALLOC_SIZE(A) __attribute__((alloc_size(A)))
40# define NORETURN __attribute__((noreturn))
41#else
42# define PRINTF_FUNCTION(A,B)
43# define ARG_UNUSED /**/
44# define WARN_UNUSED_RESULT /**/
45# define ALLOC /**/
46# define ALLOC_SIZE(A) /**/
47# define NORETURN /**/
48#endif
49
50#ifdef WANT_DEEPER_PRINTF_CHECKS
51# define ALMOST_PRINTF(A, B) PRINTF_FUNCTION(A, B)
52#else
53# define ALMOST_PRINTF(A, B)
54#endif
55
56
57/* Some operating systems (naughtily, imo) include a definition for "uchar" in
58the standard header files, so we use "uschar". Solaris has u_char in
59sys/types.h. This is just a typing convenience, of course. */
60
61typedef unsigned char uschar;
62typedef unsigned BOOL;
63/* We also have SIGNAL_BOOL, which requires signal.h be included, so is defined
64elsewhere */
65
66
67/* These macros save typing for the casting that is needed to cope with the
68mess that is "char" in ISO/ANSI C. Having now been bitten enough times by
69systems where "char" is actually signed, I've converted Exim to use entirely
70unsigned chars, except in a few special places such as arguments that are
71almost always literal strings. */
72
73#define CS (char *)
74#define CCS (const char *)
75#define CSS (char **)
76#define US (unsigned char *)
77#define CUS (const unsigned char *)
78#define USS (unsigned char **)
79#define CUSS (const unsigned char **)
80#define CCSS (const char **)
81
82/* The C library string functions expect "char *" arguments. Use macros to
83avoid having to write a cast each time. We do this for string and file
84functions that are called quite often; for other calls to external libraries
85(which are on the whole special-purpose) we just use individual casts. */
86
87#define Uatoi(s) atoi(CCS(s))
88#define Uatol(s) atol(CCS(s))
89#define Uchdir(s) chdir(CCS(s))
90#define Uchmod(s,n) chmod(CCS(s),n)
91#define Ufgets(b,n,f) fgets(CS(b),n,f)
92#define Ufopen(s,t) exim_fopen(CCS(s),CCS(t))
93#define Ulink(s,t) link(CCS(s),CCS(t))
94#define Ulstat(s,t) lstat(CCS(s),t)
95
96#ifdef O_BINARY /* This is for Cygwin, */
97#define Uopen(s,n,m) exim_open(CCS(s),(n)|O_BINARY,m) /* where all files must */
98#define Uopen2(s,n) exim_open2(CCS(s),(n)|O_BINARY)
99#else /* be opened as binary */
100#define Uopen(s,n,m) exim_open(CCS(s),n,m) /* to avoid problems */
101#define Uopen2(s,n) exim_open2(CCS(s),n)
102#endif /* with CRLF endings. */
103#define Uread(f,b,l) read(f,CS(b),l)
104#define Urename(s,t) rename(CCS(s),CCS(t))
105#define Ustat(s,t) stat(CCS(s),t)
106#define Ustrcat(s,t) __Ustrcat(s, CUS(t), __FUNCTION__, __LINE__)
107#define Ustrchr(s,n) US strchr(CCS(s),n)
108#define CUstrchr(s,n) CUS strchr(CCS(s),n)
109#define CUstrerror(n) CUS strerror(n)
110#define Ustrcmp(s,t) strcmp(CCS(s),CCS(t))
111#define Ustrcpy(s,t) __Ustrcpy(s, CUS(t), __FUNCTION__, __LINE__)
112#define Ustrcpy_nt(s,t) strcpy(CS s, CCS t) /* no taint check */
113#define Ustrcspn(s,t) strcspn(CCS(s),CCS(t))
114#define Ustrftime(s,m,f,t) strftime(CS(s),m,f,t)
115#define Ustrlen(s) (int)strlen(CCS(s))
116#define Ustrncat(s,t,n) __Ustrncat(s, CUS(t),n, __FUNCTION__, __LINE__)
117#define Ustrncmp(s,t,n) strncmp(CCS(s),CCS(t),n)
118#define Ustrncpy(s,t,n) __Ustrncpy(s, CUS(t),n, __FUNCTION__, __LINE__)
119#define Ustrncpy_nt(s,t,n) strncpy(CS s, CCS t, n) /* no taint check */
120#define Ustrpbrk(s,t) strpbrk(CCS(s),CCS(t))
121#define Ustrrchr(s,n) US strrchr(CCS(s),n)
122#define CUstrrchr(s,n) CUS strrchr(CCS(s),n)
123#define Ustrspn(s,t) strspn(CCS(s),CCS(t))
124#define Ustrstr(s,t) US strstr(CCS(s),CCS(t))
125#define CUstrstr(s,t) CUS strstr(CCS(s),CCS(t))
126#define Ustrtod(s,t) strtod(CCS(s),CSS(t))
127#define Ustrtol(s,t,b) strtol(CCS(s),CSS(t),b)
128#define Ustrtoul(s,t,b) strtoul(CCS(s),CSS(t),b)
129#define Uunlink(s) unlink(CCS(s))
130
131extern void die_tainted(const uschar *, const uschar *, int);
132
133/* Predicate: if an address is in a tainted pool.
134By extension, a variable pointing to this address is tainted.
135*/
136
137static inline BOOL
138is_tainted(const void * p)
139{
140#if defined(COMPILE_UTILITY) || defined(MACRO_PREDEF)
141return FALSE;
142
143#elif !defined(TAINT_CHECK_FAST)
144extern BOOL is_tainted_fn(const void *);
145return is_tainted_fn(p);
146
147#else
148extern void * tainted_base, * tainted_top;
149return p >= tainted_base && p < tainted_top;
150#endif
151}
152
153static inline uschar * __Ustrcat(uschar * dst, const uschar * src, const char * func, int line)
154{
155#if !defined(COMPILE_UTILITY) && !defined(MACRO_PREDEF)
156if (!is_tainted(dst) && is_tainted(src)) die_tainted(US"Ustrcat", CUS func, line);
157#endif
158return US strcat(CS dst, CCS src);
159}
160static inline uschar * __Ustrcpy(uschar * dst, const uschar * src, const char * func, int line)
161{
162#if !defined(COMPILE_UTILITY) && !defined(MACRO_PREDEF)
163if (!is_tainted(dst) && is_tainted(src)) die_tainted(US"Ustrcpy", CUS func, line);
164#endif
165return US strcpy(CS dst, CCS src);
166}
167static inline uschar * __Ustrncat(uschar * dst, const uschar * src, size_t n, const char * func, int line)
168{
169#if !defined(COMPILE_UTILITY) && !defined(MACRO_PREDEF)
170if (!is_tainted(dst) && is_tainted(src)) die_tainted(US"Ustrncat", CUS func, line);
171#endif
172return US strncat(CS dst, CCS src, n);
173}
174static inline uschar * __Ustrncpy(uschar * dst, const uschar * src, size_t n, const char * func, int line)
175{
176#if !defined(COMPILE_UTILITY) && !defined(MACRO_PREDEF)
177if (!is_tainted(dst) && is_tainted(src)) die_tainted(US"Ustrncpy", CUS func, line);
178#endif
179return US strncpy(CS dst, CCS src, n);
180}
181/*XXX will likely need unchecked copy also */
182
183#endif
184/* End of mytypes.h */