src/common/util.h

   1 /* Copyright (c) 2003-2004, Roger Dingledine
   2  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   3  * Copyright (c) 2007-2010, The Tor Project, Inc. */
   4 /* See LICENSE for licensing information */
   5
   6 /**
   7  * \file util.h
   8  * \brief Headers for util.c
   9  **/
  10
  11 #ifndef _TOR_UTIL_H
  12 #define _TOR_UTIL_H
  13
  14 #include "orconfig.h"
  15 #include "torint.h"
  16 #include "compat.h"
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19
  20 #ifndef O_BINARY
  21 #define O_BINARY 0
  22 #endif
  23 #ifndef O_TEXT
  24 #define O_TEXT 0
  25 #endif
  26
  27 /* Replace assert() with a variant that sends failures to the log before
  28  * calling assert() normally.
  29  */
  30 #ifdef NDEBUG
  31 /* Nobody should ever want to build with NDEBUG set.  99% of our asserts will
  32  * be outside the critical path anyway, so it's silly to disable bug-checking
  33  * throughout the entire program just because a few asserts are slowing you
  34  * down.  Profile, optimize the critical path, and keep debugging on.
  35  *
  36  * And I'm not just saying that because some of our asserts check
  37  * security-critical properties.
  38  */
  39 #error "Sorry; we don't support building with NDEBUG."
  40 #endif
  41
  42 /** Like assert(3), but send assertion failures to the log as well as to
  43  * stderr. */
  44 #define tor_assert(expr) STMT_BEGIN                                     \
  45     if (PREDICT_UNLIKELY(!(expr))) {                                    \
  46       log(LOG_ERR, LD_BUG, "%s:%d: %s: Assertion %s failed; aborting.", \
  47           _SHORT_FILE_, __LINE__, __func__, #expr);                     \
  48       fprintf(stderr,"%s:%d %s: Assertion %s failed; aborting.\n",      \
  49               _SHORT_FILE_, __LINE__, __func__, #expr);                 \
  50       abort();                                                          \
  51     } STMT_END
  52
  53 /* If we're building with dmalloc, we want all of our memory allocation
  54  * functions to take an extra file/line pair of arguments.  If not, not.
  55  * We define DMALLOC_PARAMS to the extra parameters to insert in the
  56  * function prototypes, and DMALLOC_ARGS to the extra arguments to add
  57  * to calls. */
  58 #ifdef USE_DMALLOC
  59 #define DMALLOC_PARAMS , const char *file, const int line
  60 #define DMALLOC_ARGS , _SHORT_FILE_, __LINE__
  61 #else
  62 #define DMALLOC_PARAMS
  63 #define DMALLOC_ARGS
  64 #endif
  65
  66 /** Define this if you want Tor to crash when any problem comes up,
  67  * so you can get a coredump and track things down. */
  68 // #define tor_fragile_assert() tor_assert(0)
  69 #define tor_fragile_assert()
  70
  71 /* Memory management */
  72 void *_tor_malloc(size_t size DMALLOC_PARAMS) ATTR_MALLOC;
  73 void *_tor_malloc_zero(size_t size DMALLOC_PARAMS) ATTR_MALLOC;
  74 void *_tor_malloc_roundup(size_t *size DMALLOC_PARAMS) ATTR_MALLOC;
  75 void *_tor_realloc(void *ptr, size_t size DMALLOC_PARAMS);
  76 char *_tor_strdup(const char *s DMALLOC_PARAMS) ATTR_MALLOC ATTR_NONNULL((1));
  77 char *_tor_strndup(const char *s, size_t n DMALLOC_PARAMS)
  78   ATTR_MALLOC ATTR_NONNULL((1));
  79 void *_tor_memdup(const void *mem, size_t len DMALLOC_PARAMS)
  80   ATTR_MALLOC ATTR_NONNULL((1));
  81 void _tor_free(void *mem);
  82 #ifdef USE_DMALLOC
  83 extern int dmalloc_free(const char *file, const int line, void *pnt,
  84                         const int func_id);
  85 #define tor_free(p) STMT_BEGIN \
  86     if (PREDICT_LIKELY((p)!=NULL)) {                \
  87       dmalloc_free(_SHORT_FILE_, __LINE__, (p), 0); \
  88       (p)=NULL;                                     \
  89     }                                               \
  90   STMT_END
  91 #else
  92 /** Release memory allocated by tor_malloc, tor_realloc, tor_strdup, etc.
  93  * Unlike the free() function, tor_free() will still work on NULL pointers,
  94  * and it sets the pointer value to NULL after freeing it.
  95  *
  96  * This is a macro.  If you need a function pointer to release memory from
  97  * tor_malloc(), use _tor_free().
  98  */
  99 #define tor_free(p) STMT_BEGIN                                 \
 100     if (PREDICT_LIKELY((p)!=NULL)) {                           \
 101       free(p);                                                 \
 102       (p)=NULL;                                                \
 103     }                                                          \
 104   STMT_END
 105 #endif
 106
 107 #define tor_malloc(size)       _tor_malloc(size DMALLOC_ARGS)
 108 #define tor_malloc_zero(size)  _tor_malloc_zero(size DMALLOC_ARGS)
 109 #define tor_malloc_roundup(szp) _tor_malloc_roundup(szp DMALLOC_ARGS)
 110 #define tor_realloc(ptr, size) _tor_realloc(ptr, size DMALLOC_ARGS)
 111 #define tor_strdup(s)          _tor_strdup(s DMALLOC_ARGS)
 112 #define tor_strndup(s, n)      _tor_strndup(s, n DMALLOC_ARGS)
 113 #define tor_memdup(s, n)       _tor_memdup(s, n DMALLOC_ARGS)
 114
 115 void tor_log_mallinfo(int severity);
 116
 117 /** Return the offset of <b>member</b> within the type <b>tp</b>, in bytes */
 118 #if defined(__GNUC__) && __GNUC__ > 3
 119 #define STRUCT_OFFSET(tp, member) __builtin_offsetof(tp, member)
 120 #else
 121  #define STRUCT_OFFSET(tp, member) \
 122    ((off_t) (((char*)&((tp*)0)->member)-(char*)0))
 123 #endif
 124
 125 /** Macro: yield a pointer to the field at position <b>off</b> within the
 126  * structure <b>st</b>.  Example:
 127  * <pre>
 128  *   struct a { int foo; int bar; } x;
 129  *   off_t bar_offset = STRUCT_OFFSET(struct a, bar);
 130  *   int *bar_p = STRUCT_VAR_P(&x, bar_offset);
 131  *   *bar_p = 3;
 132  * </pre>
 133  */
 134 #define STRUCT_VAR_P(st, off) ((void*) ( ((char*)(st)) + (off) ) )
 135
 136 /** Macro: yield a pointer to an enclosing structure given a pointer to
 137  * a substructure at offset <b>off</b>. Example:
 138  * <pre>
 139  *   struct base { ... };
 140  *   struct subtype { int x; struct base b; } x;
 141  *   struct base *bp = &x.base;
 142  *   struct *sp = SUBTYPE_P(bp, struct subtype, b);
 143  * </pre>
 144  */
 145 #define SUBTYPE_P(p, subtype, basemember) \
 146   ((void*) ( ((char*)(p)) - STRUCT_OFFSET(subtype, basemember) ))
 147
 148 /* Logic */
 149 /** Macro: true if two values have the same boolean value. */
 150 #define bool_eq(a,b) (!(a)==!(b))
 151 /** Macro: true if two values have different boolean values. */
 152 #define bool_neq(a,b) (!(a)!=!(b))
 153
 154 /* Math functions */
 155 int tor_log2(uint64_t u64) ATTR_CONST;
 156 uint64_t round_to_power_of_2(uint64_t u64);
 157
 158 /* String manipulation */
 159
 160 /** Allowable characters in a hexadecimal string. */
 161 #define HEX_CHARACTERS "0123456789ABCDEFabcdef"
 162 void tor_strlower(char *s) ATTR_NONNULL((1));
 163 void tor_strupper(char *s) ATTR_NONNULL((1));
 164 int tor_strisprint(const char *s) ATTR_PURE ATTR_NONNULL((1));
 165 int tor_strisnonupper(const char *s) ATTR_PURE ATTR_NONNULL((1));
 166 int strcmpstart(const char *s1, const char *s2) ATTR_PURE ATTR_NONNULL((1,2));
 167 int strcmp_len(const char *s1, const char *s2, size_t len)
 168   ATTR_PURE ATTR_NONNULL((1,2));
 169 int strcasecmpstart(const char *s1, const char *s2)
 170   ATTR_PURE ATTR_NONNULL((1,2));
 171 int strcmpend(const char *s1, const char *s2) ATTR_PURE ATTR_NONNULL((1,2));
 172 int strcasecmpend(const char *s1, const char *s2)
 173   ATTR_PURE ATTR_NONNULL((1,2));
 174 int memcmpstart(const void *mem, size_t memlen,
 175                 const char *prefix) ATTR_PURE;
 176
 177 void tor_strstrip(char *s, const char *strip) ATTR_NONNULL((1,2));
 178 long tor_parse_long(const char *s, int base, long min,
 179                     long max, int *ok, char **next);
 180 unsigned long tor_parse_ulong(const char *s, int base, unsigned long min,
 181                               unsigned long max, int *ok, char **next);
 182 uint64_t tor_parse_uint64(const char *s, int base, uint64_t min,
 183                          uint64_t max, int *ok, char **next);
 184 const char *hex_str(const char *from, size_t fromlen) ATTR_NONNULL((1));
 185 const char *eat_whitespace(const char *s) ATTR_PURE;
 186 const char *eat_whitespace_eos(const char *s, const char *eos) ATTR_PURE;
 187 const char *eat_whitespace_no_nl(const char *s) ATTR_PURE;
 188 const char *eat_whitespace_eos_no_nl(const char *s, const char *eos) ATTR_PURE;
 189 const char *find_whitespace(const char *s) ATTR_PURE;
 190 const char *find_whitespace_eos(const char *s, const char *eos) ATTR_PURE;
 191 int tor_mem_is_zero(const char *mem, size_t len) ATTR_PURE;
 192 int tor_digest_is_zero(const char *digest) ATTR_PURE;
 193 char *esc_for_log(const char *string) ATTR_MALLOC;
 194 const char *escaped(const char *string);
 195 struct smartlist_t;
 196 void wrap_string(struct smartlist_t *out, const char *string, size_t width,
 197                  const char *prefix0, const char *prefixRest);
 198 int tor_vsscanf(const char *buf, const char *pattern, va_list ap);
 199 int tor_sscanf(const char *buf, const char *pattern, ...)
 200 #ifdef __GNUC__
 201   __attribute__((format(scanf, 2, 3)))
 202 #endif
 203   ;
 204
 205 int hex_decode_digit(char c);
 206 void base16_encode(char *dest, size_t destlen, const char *src, size_t srclen);
 207 int base16_decode(char *dest, size_t destlen, const char *src, size_t srclen);
 208
 209 /* Time helpers */
 210 long tv_udiff(const struct timeval *start, const struct timeval *end);
 211 time_t tor_timegm(struct tm *tm);
 212 #define RFC1123_TIME_LEN 29
 213 void format_rfc1123_time(char *buf, time_t t);
 214 int parse_rfc1123_time(const char *buf, time_t *t);
 215 #define ISO_TIME_LEN 19
 216 void format_local_iso_time(char *buf, time_t t);
 217 void format_iso_time(char *buf, time_t t);
 218 int parse_iso_time(const char *buf, time_t *t);
 219 int parse_http_time(const char *buf, struct tm *tm);
 220 int format_time_interval(char *out, size_t out_len, long interval);
 221
 222 /* Cached time */
 223 #ifdef TIME_IS_FAST
 224 #define approx_time() time(NULL)
 225 #define update_approx_time(t) STMT_NIL
 226 #else
 227 time_t approx_time(void);
 228 void update_approx_time(time_t now);
 229 #endif
 230
 231 /* Fuzzy time. */
 232 void ftime_set_maximum_sloppiness(int seconds);
 233 void ftime_set_estimated_skew(int seconds);
 234 /* typedef struct ftime_t { time_t earliest; time_t latest; } ftime_t; */
 235 /* void ftime_get_window(time_t now, ftime_t *ft_out); */
 236 int ftime_maybe_after(time_t now, time_t when);
 237 int ftime_maybe_before(time_t now, time_t when);
 238 int ftime_definitely_after(time_t now, time_t when);
 239 int ftime_definitely_before(time_t now, time_t when);
 240
 241 /* File helpers */
 242 ssize_t write_all(int fd, const char *buf, size_t count, int isSocket);
 243 ssize_t read_all(int fd, char *buf, size_t count, int isSocket);
 244
 245 /** Return values from file_status(); see that function's documentation
 246  * for details. */
 247 typedef enum { FN_ERROR, FN_NOENT, FN_FILE, FN_DIR } file_status_t;
 248 file_status_t file_status(const char *filename);
 249
 250 /** Possible behaviors for check_private_dir() on encountering a nonexistent
 251  * directory; see that function's documentation for details. */
 252 typedef enum { CPD_NONE, CPD_CREATE, CPD_CHECK } cpd_check_t;
 253 int check_private_dir(const char *dirname, cpd_check_t check);
 254 #define OPEN_FLAGS_REPLACE (O_WRONLY|O_CREAT|O_TRUNC)
 255 #define OPEN_FLAGS_APPEND (O_WRONLY|O_CREAT|O_APPEND)
 256 typedef struct open_file_t open_file_t;
 257 int start_writing_to_file(const char *fname, int open_flags, int mode,
 258                           open_file_t **data_out);
 259 FILE *start_writing_to_stdio_file(const char *fname, int open_flags, int mode,
 260                                   open_file_t **data_out);
 261 FILE *fdopen_file(open_file_t *file_data);
 262 int finish_writing_to_file(open_file_t *file_data);
 263 int abort_writing_to_file(open_file_t *file_data);
 264 int write_str_to_file(const char *fname, const char *str, int bin);
 265 int write_bytes_to_file(const char *fname, const char *str, size_t len,
 266                         int bin);
 267 /** An ad-hoc type to hold a string of characters and a count; used by
 268  * write_chunks_to_file. */
 269 typedef struct sized_chunk_t {
 270   const char *bytes;
 271   size_t len;
 272 } sized_chunk_t;
 273 int write_chunks_to_file(const char *fname, const struct smartlist_t *chunks,
 274                          int bin);
 275 int append_bytes_to_file(const char *fname, const char *str, size_t len,
 276                          int bin);
 277
 278 /** Flag for read_file_to_str: open the file in binary mode. */
 279 #define RFTS_BIN            1
 280 /** Flag for read_file_to_str: it's okay if the file doesn't exist. */
 281 #define RFTS_IGNORE_MISSING 2
 282
 283 struct stat;
 284 char *read_file_to_str(const char *filename, int flags, struct stat *stat_out)
 285   ATTR_MALLOC;
 286 const char *parse_config_line_from_str(const char *line,
 287                                        char **key_out, char **value_out);
 288 char *expand_filename(const char *filename);
 289 struct smartlist_t *tor_listdir(const char *dirname);
 290 int path_is_relative(const char *filename) ATTR_PURE;
 291
 292 /* Process helpers */
 293 void start_daemon(void);
 294 void finish_daemon(const char *desired_cwd);
 295 void write_pidfile(char *filename);
 296
 297 #endif
 298