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tor/src/common/util.h
Nick Mathewson 42731f69ef Merge branch 'bug8037_squashed' into maint-0.2.4
2013-04-17 10:45:45 -04:00

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/* Copyright (c) 2003-2004, Roger Dingledine
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2013, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file util.h
* \brief Headers for util.c
**/
#ifndef TOR_UTIL_H
#define TOR_UTIL_H
#include "orconfig.h"
#include "torint.h"
#include "compat.h"
#include "di_ops.h"
#include <stdio.h>
#include <stdlib.h>
#ifdef _WIN32
/* for the correct alias to struct stat */
#include <sys/stat.h>
#endif
#ifndef O_BINARY
#define O_BINARY 0
#endif
#ifndef O_TEXT
#define O_TEXT 0
#endif
/* Replace assert() with a variant that sends failures to the log before
* calling assert() normally.
*/
#ifdef NDEBUG
/* Nobody should ever want to build with NDEBUG set. 99% of our asserts will
* be outside the critical path anyway, so it's silly to disable bug-checking
* throughout the entire program just because a few asserts are slowing you
* down. Profile, optimize the critical path, and keep debugging on.
*
* And I'm not just saying that because some of our asserts check
* security-critical properties.
*/
#error "Sorry; we don't support building with NDEBUG."
#endif
/** Like assert(3), but send assertion failures to the log as well as to
* stderr. */
#define tor_assert(expr) STMT_BEGIN \
if (PREDICT_UNLIKELY(!(expr))) { \
log_err(LD_BUG, "%s:%d: %s: Assertion %s failed; aborting.", \
SHORT_FILE__, __LINE__, __func__, #expr); \
fprintf(stderr,"%s:%d %s: Assertion %s failed; aborting.\n", \
SHORT_FILE__, __LINE__, __func__, #expr); \
abort(); \
} STMT_END
/* If we're building with dmalloc, we want all of our memory allocation
* functions to take an extra file/line pair of arguments. If not, not.
* We define DMALLOC_PARAMS to the extra parameters to insert in the
* function prototypes, and DMALLOC_ARGS to the extra arguments to add
* to calls. */
#ifdef USE_DMALLOC
#define DMALLOC_PARAMS , const char *file, const int line
#define DMALLOC_ARGS , SHORT_FILE__, __LINE__
#else
#define DMALLOC_PARAMS
#define DMALLOC_ARGS
#endif
/** Define this if you want Tor to crash when any problem comes up,
* so you can get a coredump and track things down. */
// #define tor_fragile_assert() tor_assert(0)
#define tor_fragile_assert()
/* Memory management */
void *tor_malloc_(size_t size DMALLOC_PARAMS) ATTR_MALLOC;
void *tor_malloc_zero_(size_t size DMALLOC_PARAMS) ATTR_MALLOC;
void *tor_calloc_(size_t nmemb, size_t size DMALLOC_PARAMS) ATTR_MALLOC;
void *tor_realloc_(void *ptr, size_t size DMALLOC_PARAMS);
char *tor_strdup_(const char *s DMALLOC_PARAMS) ATTR_MALLOC ATTR_NONNULL((1));
char *tor_strndup_(const char *s, size_t n DMALLOC_PARAMS)
ATTR_MALLOC ATTR_NONNULL((1));
void *tor_memdup_(const void *mem, size_t len DMALLOC_PARAMS)
ATTR_MALLOC ATTR_NONNULL((1));
void *tor_memdup_nulterm_(const void *mem, size_t len DMALLOC_PARAMS)
ATTR_MALLOC ATTR_NONNULL((1));
void tor_free_(void *mem);
#ifdef USE_DMALLOC
extern int dmalloc_free(const char *file, const int line, void *pnt,
const int func_id);
#define tor_free(p) STMT_BEGIN \
if (PREDICT_LIKELY((p)!=NULL)) { \
dmalloc_free(SHORT_FILE__, __LINE__, (p), 0); \
(p)=NULL; \
} \
STMT_END
#else
/** Release memory allocated by tor_malloc, tor_realloc, tor_strdup, etc.
* Unlike the free() function, tor_free() will still work on NULL pointers,
* and it sets the pointer value to NULL after freeing it.
*
* This is a macro. If you need a function pointer to release memory from
* tor_malloc(), use tor_free_().
*/
#define tor_free(p) STMT_BEGIN \
if (PREDICT_LIKELY((p)!=NULL)) { \
free(p); \
(p)=NULL; \
} \
STMT_END
#endif
#define tor_malloc(size) tor_malloc_(size DMALLOC_ARGS)
#define tor_malloc_zero(size) tor_malloc_zero_(size DMALLOC_ARGS)
#define tor_calloc(nmemb,size) tor_calloc_(nmemb, size DMALLOC_ARGS)
#define tor_realloc(ptr, size) tor_realloc_(ptr, size DMALLOC_ARGS)
#define tor_strdup(s) tor_strdup_(s DMALLOC_ARGS)
#define tor_strndup(s, n) tor_strndup_(s, n DMALLOC_ARGS)
#define tor_memdup(s, n) tor_memdup_(s, n DMALLOC_ARGS)
#define tor_memdup_nulterm(s, n) tor_memdup_nulterm_(s, n DMALLOC_ARGS)
void tor_log_mallinfo(int severity);
/** Return the offset of <b>member</b> within the type <b>tp</b>, in bytes */
#if defined(__GNUC__) && __GNUC__ > 3
#define STRUCT_OFFSET(tp, member) __builtin_offsetof(tp, member)
#else
#define STRUCT_OFFSET(tp, member) \
((off_t) (((char*)&((tp*)0)->member)-(char*)0))
#endif
/** Macro: yield a pointer to the field at position <b>off</b> within the
* structure <b>st</b>. Example:
* <pre>
* struct a { int foo; int bar; } x;
* off_t bar_offset = STRUCT_OFFSET(struct a, bar);
* int *bar_p = STRUCT_VAR_P(&x, bar_offset);
* *bar_p = 3;
* </pre>
*/
#define STRUCT_VAR_P(st, off) ((void*) ( ((char*)(st)) + (off) ) )
/** Macro: yield a pointer to an enclosing structure given a pointer to
* a substructure at offset <b>off</b>. Example:
* <pre>
* struct base { ... };
* struct subtype { int x; struct base b; } x;
* struct base *bp = &x.base;
* struct *sp = SUBTYPE_P(bp, struct subtype, b);
* </pre>
*/
#define SUBTYPE_P(p, subtype, basemember) \
((void*) ( ((char*)(p)) - STRUCT_OFFSET(subtype, basemember) ))
/* Logic */
/** Macro: true if two values have the same boolean value. */
#define bool_eq(a,b) (!(a)==!(b))
/** Macro: true if two values have different boolean values. */
#define bool_neq(a,b) (!(a)!=!(b))
/* Math functions */
double tor_mathlog(double d) ATTR_CONST;
long tor_lround(double d) ATTR_CONST;
int64_t tor_llround(double d) ATTR_CONST;
int tor_log2(uint64_t u64) ATTR_CONST;
uint64_t round_to_power_of_2(uint64_t u64);
unsigned round_to_next_multiple_of(unsigned number, unsigned divisor);
uint32_t round_uint32_to_next_multiple_of(uint32_t number, uint32_t divisor);
uint64_t round_uint64_to_next_multiple_of(uint64_t number, uint64_t divisor);
int n_bits_set_u8(uint8_t v);
/* Compute the CEIL of <b>a</b> divided by <b>b</b>, for nonnegative <b>a</b>
* and positive <b>b</b>. Works on integer types only. Not defined if a+b can
* overflow. */
#define CEIL_DIV(a,b) (((a)+(b)-1)/(b))
/* Return <b>v</b> if it's between <b>min</b> and <b>max</b>. Otherwise
* return <b>min</b> if <b>v</b> is smaller than <b>min</b>, or <b>max</b> if
* <b>b</b> is larger than <b>max</b>.
*
* Requires that <b>min</b> is no more than <b>max</b>. May evaluate any of
* its arguments more than once! */
#define CLAMP(min,v,max) \
( ((v) < (min)) ? (min) : \
((v) > (max)) ? (max) : \
(v) )
/* String manipulation */
/** Allowable characters in a hexadecimal string. */
#define HEX_CHARACTERS "0123456789ABCDEFabcdef"
void tor_strlower(char *s) ATTR_NONNULL((1));
void tor_strupper(char *s) ATTR_NONNULL((1));
int tor_strisprint(const char *s) ATTR_NONNULL((1));
int tor_strisnonupper(const char *s) ATTR_NONNULL((1));
int strcmp_opt(const char *s1, const char *s2);
int strcmpstart(const char *s1, const char *s2) ATTR_NONNULL((1,2));
int strcmp_len(const char *s1, const char *s2, size_t len) ATTR_NONNULL((1,2));
int strcasecmpstart(const char *s1, const char *s2) ATTR_NONNULL((1,2));
int strcmpend(const char *s1, const char *s2) ATTR_NONNULL((1,2));
int strcasecmpend(const char *s1, const char *s2) ATTR_NONNULL((1,2));
int fast_memcmpstart(const void *mem, size_t memlen, const char *prefix);
void tor_strclear(char *s);
void tor_strstrip(char *s, const char *strip) ATTR_NONNULL((1,2));
long tor_parse_long(const char *s, int base, long min,
long max, int *ok, char **next);
unsigned long tor_parse_ulong(const char *s, int base, unsigned long min,
unsigned long max, int *ok, char **next);
double tor_parse_double(const char *s, double min, double max, int *ok,
char **next);
uint64_t tor_parse_uint64(const char *s, int base, uint64_t min,
uint64_t max, int *ok, char **next);
const char *hex_str(const char *from, size_t fromlen) ATTR_NONNULL((1));
const char *eat_whitespace(const char *s);
const char *eat_whitespace_eos(const char *s, const char *eos);
const char *eat_whitespace_no_nl(const char *s);
const char *eat_whitespace_eos_no_nl(const char *s, const char *eos);
const char *find_whitespace(const char *s);
const char *find_whitespace_eos(const char *s, const char *eos);
const char *find_str_at_start_of_line(const char *haystack,
const char *needle);
int string_is_C_identifier(const char *string);
int tor_mem_is_zero(const char *mem, size_t len);
int tor_digest_is_zero(const char *digest);
int tor_digest256_is_zero(const char *digest);
char *esc_for_log(const char *string) ATTR_MALLOC;
const char *escaped(const char *string);
struct smartlist_t;
int tor_vsscanf(const char *buf, const char *pattern, va_list ap)
#ifdef __GNUC__
__attribute__((format(scanf, 2, 0)))
#endif
;
int tor_sscanf(const char *buf, const char *pattern, ...)
#ifdef __GNUC__
__attribute__((format(scanf, 2, 3)))
#endif
;
void smartlist_add_asprintf(struct smartlist_t *sl, const char *pattern, ...)
CHECK_PRINTF(2, 3);
void smartlist_add_vasprintf(struct smartlist_t *sl, const char *pattern,
va_list args)
CHECK_PRINTF(2, 0);
int hex_decode_digit(char c);
void base16_encode(char *dest, size_t destlen, const char *src, size_t srclen);
int base16_decode(char *dest, size_t destlen, const char *src, size_t srclen);
/* Time helpers */
long tv_udiff(const struct timeval *start, const struct timeval *end);
long tv_mdiff(const struct timeval *start, const struct timeval *end);
int tor_timegm(const struct tm *tm, time_t *time_out);
#define RFC1123_TIME_LEN 29
void format_rfc1123_time(char *buf, time_t t);
int parse_rfc1123_time(const char *buf, time_t *t);
#define ISO_TIME_LEN 19
#define ISO_TIME_USEC_LEN (ISO_TIME_LEN+7)
void format_local_iso_time(char *buf, time_t t);
void format_iso_time(char *buf, time_t t);
void format_iso_time_nospace(char *buf, time_t t);
void format_iso_time_nospace_usec(char *buf, const struct timeval *tv);
int parse_iso_time(const char *buf, time_t *t);
int parse_http_time(const char *buf, struct tm *tm);
int format_time_interval(char *out, size_t out_len, long interval);
/* Cached time */
#ifdef TIME_IS_FAST
#define approx_time() time(NULL)
#define update_approx_time(t) STMT_NIL
#else
time_t approx_time(void);
void update_approx_time(time_t now);
#endif
/* Rate-limiter */
/** A ratelim_t remembers how often an event is occurring, and how often
* it's allowed to occur. Typical usage is something like:
*
<pre>
if (possibly_very_frequent_event()) {
const int INTERVAL = 300;
static ratelim_t warning_limit = RATELIM_INIT(INTERVAL);
char *m;
if ((m = rate_limit_log(&warning_limit, approx_time()))) {
log_warn(LD_GENERAL, "The event occurred!%s", m);
tor_free(m);
}
}
</pre>
As a convenience wrapper for logging, you can replace the above with:
<pre>
if (possibly_very_frequent_event()) {
static ratelim_t warning_limit = RATELIM_INIT(300);
log_fn_ratelim(&warning_limit, LOG_WARN, LD_GENERAL,
"The event occurred!");
}
</pre>
*/
typedef struct ratelim_t {
int rate;
time_t last_allowed;
int n_calls_since_last_time;
} ratelim_t;
#define RATELIM_INIT(r) { (r), 0, 0 }
char *rate_limit_log(ratelim_t *lim, time_t now);
/* File helpers */
ssize_t write_all(tor_socket_t fd, const char *buf, size_t count,int isSocket);
ssize_t read_all(tor_socket_t fd, char *buf, size_t count, int isSocket);
/** Status of an I/O stream. */
enum stream_status {
IO_STREAM_OKAY,
IO_STREAM_EAGAIN,
IO_STREAM_TERM,
IO_STREAM_CLOSED
};
const char *stream_status_to_string(enum stream_status stream_status);
enum stream_status get_string_from_pipe(FILE *stream, char *buf, size_t count);
/** Return values from file_status(); see that function's documentation
* for details. */
typedef enum { FN_ERROR, FN_NOENT, FN_FILE, FN_DIR } file_status_t;
file_status_t file_status(const char *filename);
/** Possible behaviors for check_private_dir() on encountering a nonexistent
* directory; see that function's documentation for details. */
typedef unsigned int cpd_check_t;
#define CPD_NONE 0
#define CPD_CREATE 1
#define CPD_CHECK 2
#define CPD_GROUP_OK 4
#define CPD_CHECK_MODE_ONLY 8
int check_private_dir(const char *dirname, cpd_check_t check,
const char *effective_user);
#define OPEN_FLAGS_REPLACE (O_WRONLY|O_CREAT|O_TRUNC)
#define OPEN_FLAGS_APPEND (O_WRONLY|O_CREAT|O_APPEND)
#define OPEN_FLAGS_DONT_REPLACE (O_CREAT|O_EXCL|O_APPEND|O_WRONLY)
typedef struct open_file_t open_file_t;
int start_writing_to_file(const char *fname, int open_flags, int mode,
open_file_t **data_out);
FILE *start_writing_to_stdio_file(const char *fname, int open_flags, int mode,
open_file_t **data_out);
FILE *fdopen_file(open_file_t *file_data);
int finish_writing_to_file(open_file_t *file_data);
int abort_writing_to_file(open_file_t *file_data);
int write_str_to_file(const char *fname, const char *str, int bin);
int write_bytes_to_file(const char *fname, const char *str, size_t len,
int bin);
/** An ad-hoc type to hold a string of characters and a count; used by
* write_chunks_to_file. */
typedef struct sized_chunk_t {
const char *bytes;
size_t len;
} sized_chunk_t;
int write_chunks_to_file(const char *fname, const struct smartlist_t *chunks,
int bin);
int append_bytes_to_file(const char *fname, const char *str, size_t len,
int bin);
int write_bytes_to_new_file(const char *fname, const char *str, size_t len,
int bin);
/** Flag for read_file_to_str: open the file in binary mode. */
#define RFTS_BIN 1
/** Flag for read_file_to_str: it's okay if the file doesn't exist. */
#define RFTS_IGNORE_MISSING 2
#ifndef _WIN32
struct stat;
#endif
char *read_file_to_str(const char *filename, int flags, struct stat *stat_out)
ATTR_MALLOC;
char *read_file_to_str_until_eof(int fd, size_t max_bytes_to_read,
size_t *sz_out)
ATTR_MALLOC;
const char *parse_config_line_from_str_verbose(const char *line,
char **key_out, char **value_out,
const char **err_out);
#define parse_config_line_from_str(line,key_out,value_out) \
parse_config_line_from_str_verbose((line),(key_out),(value_out),NULL)
char *expand_filename(const char *filename);
struct smartlist_t *tor_listdir(const char *dirname);
int path_is_relative(const char *filename);
/* Process helpers */
void start_daemon(void);
void finish_daemon(const char *desired_cwd);
void write_pidfile(char *filename);
/* Port forwarding */
void tor_check_port_forwarding(const char *filename,
struct smartlist_t *ports_to_forward,
time_t now);
typedef struct process_handle_t process_handle_t;
typedef struct process_environment_t process_environment_t;
int tor_spawn_background(const char *const filename, const char **argv,
process_environment_t *env,
process_handle_t **process_handle_out);
#define SPAWN_ERROR_MESSAGE "ERR: Failed to spawn background process - code "
#ifdef _WIN32
HANDLE load_windows_system_library(const TCHAR *library_name);
#endif
int environment_variable_names_equal(const char *s1, const char *s2);
/* DOCDOC process_environment_t */
struct process_environment_t {
/** A pointer to a sorted empty-string-terminated sequence of
* NUL-terminated strings of the form "NAME=VALUE". */
char *windows_environment_block;
/** A pointer to a NULL-terminated array of pointers to
* NUL-terminated strings of the form "NAME=VALUE". */
char **unixoid_environment_block;
};
process_environment_t *process_environment_make(struct smartlist_t *env_vars);
void process_environment_free(process_environment_t *env);
struct smartlist_t *get_current_process_environment_variables(void);
void set_environment_variable_in_smartlist(struct smartlist_t *env_vars,
const char *new_var,
void (*free_old)(void*),
int free_p);
/* Values of process_handle_t.status. PROCESS_STATUS_NOTRUNNING must be
* 0 because tor_check_port_forwarding depends on this being the initial
* statue of the static instance of process_handle_t */
#define PROCESS_STATUS_NOTRUNNING 0
#define PROCESS_STATUS_RUNNING 1
#define PROCESS_STATUS_ERROR -1
#ifdef UTIL_PRIVATE
/** Structure to represent the state of a process with which Tor is
* communicating. The contents of this structure are private to util.c */
struct process_handle_t {
/** One of the PROCESS_STATUS_* values */
int status;
#ifdef _WIN32
HANDLE stdout_pipe;
HANDLE stderr_pipe;
PROCESS_INFORMATION pid;
#else
int stdout_pipe;
int stderr_pipe;
FILE *stdout_handle;
FILE *stderr_handle;
pid_t pid;
#endif // _WIN32
};
#endif
/* Return values of tor_get_exit_code() */
#define PROCESS_EXIT_RUNNING 1
#define PROCESS_EXIT_EXITED 0
#define PROCESS_EXIT_ERROR -1
int tor_get_exit_code(const process_handle_t *process_handle,
int block, int *exit_code);
int tor_split_lines(struct smartlist_t *sl, char *buf, int len);
#ifdef _WIN32
ssize_t tor_read_all_handle(HANDLE h, char *buf, size_t count,
const process_handle_t *process);
#else
ssize_t tor_read_all_handle(FILE *h, char *buf, size_t count,
const process_handle_t *process,
int *eof);
#endif
ssize_t tor_read_all_from_process_stdout(
const process_handle_t *process_handle, char *buf, size_t count);
ssize_t tor_read_all_from_process_stderr(
const process_handle_t *process_handle, char *buf, size_t count);
char *tor_join_win_cmdline(const char *argv[]);
int tor_process_get_pid(process_handle_t *process_handle);
#ifdef _WIN32
HANDLE tor_process_get_stdout_pipe(process_handle_t *process_handle);
#else
FILE *tor_process_get_stdout_pipe(process_handle_t *process_handle);
#endif
#ifdef _WIN32
struct smartlist_t *
tor_get_lines_from_handle(HANDLE *handle,
enum stream_status *stream_status);
#else
struct smartlist_t *
tor_get_lines_from_handle(FILE *handle,
enum stream_status *stream_status);
#endif
int tor_terminate_process(process_handle_t *process_handle);
void tor_process_handle_destroy(process_handle_t *process_handle,
int also_terminate_process);
/* ===== Insecure rng */
typedef struct tor_weak_rng_t {
uint32_t state;
} tor_weak_rng_t;
#define TOR_WEAK_RNG_INIT {383745623}
#define TOR_WEAK_RANDOM_MAX (INT_MAX)
void tor_init_weak_random(tor_weak_rng_t *weak_rng, unsigned seed);
int32_t tor_weak_random(tor_weak_rng_t *weak_rng);
int32_t tor_weak_random_range(tor_weak_rng_t *rng, int32_t top);
/** Randomly return true according to <b>rng</b> with probability 1 in
* <b>n</b> */
#define tor_weak_random_one_in_n(rng, n) (0==tor_weak_random_range((rng),(n)))
#ifdef UTIL_PRIVATE
/* Prototypes for private functions only used by util.c (and unit tests) */
int format_hex_number_for_helper_exit_status(unsigned int x, char *buf,
int max_len);
int format_helper_exit_status(unsigned char child_state,
int saved_errno, char *hex_errno);
/* Space for hex values of child state, a slash, saved_errno (with
leading minus) and newline (no null) */
#define HEX_ERRNO_SIZE (sizeof(char) * 2 + 1 + \
1 + sizeof(int) * 2 + 1)
#endif
const char *libor_get_digests(void);
#endif
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