/* Copyright (c) 2003, Roger Dingledine
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2010, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file util.c
* \brief Common functions for strings, IO, network, data structures,
* process control.
**/
/* This is required on rh7 to make strptime not complain.
*/
#define _GNU_SOURCE
#include "orconfig.h"
#include "util.h"
#include "torlog.h"
#undef log
#include "crypto.h"
#include "torint.h"
#include "container.h"
#include "address.h"
#ifdef MS_WINDOWS
#include <io.h>
#include <direct.h>
#include <process.h>
#include <tchar.h>
#else
#include <dirent.h>
#include <pwd.h>
#endif
/* math.h needs this on Linux */
#ifndef __USE_ISOC99
#define __USE_ISOC99 1
#endif
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_SYS_FCNTL_H
#include <sys/fcntl.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#ifdef HAVE_MALLOC_MALLOC_H
#include <malloc/malloc.h>
#endif
#ifdef HAVE_MALLOC_H
#ifndef OPENBSD
/* OpenBSD has a malloc.h, but for our purposes, it only exists in order to
* scold us for being so stupid as to autodetect its presence. To be fair,
* they've done this since 1996, when autoconf was only 5 years old. */
#include <malloc.h>
#endif
#endif
#ifdef HAVE_MALLOC_NP_H
#include <malloc_np.h>
#endif
/* =====
* Memory management
* ===== */
#ifdef USE_DMALLOC
#undef strndup
#include <dmalloc.h>
/* Macro to pass the extra dmalloc args to another function. */
#define DMALLOC_FN_ARGS , file, line
#if defined(HAVE_DMALLOC_STRDUP)
/* the dmalloc_strdup should be fine as defined */
#elif defined(HAVE_DMALLOC_STRNDUP)
#define dmalloc_strdup(file, line, string, xalloc_b) \
dmalloc_strndup(file, line, (string), -1, xalloc_b)
#else
#error "No dmalloc_strdup or equivalent"
#endif
#else /* not using dmalloc */
#define DMALLOC_FN_ARGS
#endif
/** Allocate a chunk of <b>size</b> bytes of memory, and return a pointer to
* result. On error, log and terminate the process. (Same as malloc(size),
* but never returns NULL.)
*
* <b>file</b> and <b>line</b> are used if dmalloc is enabled, and
* ignored otherwise.
*/
void *
_tor_malloc(size_t size DMALLOC_PARAMS)
{
void *result;
#ifndef MALLOC_ZERO_WORKS
/* Some libc mallocs don't work when size==0. Override them. */
if (size==0) {
size=1;
}
#endif
#ifdef USE_DMALLOC
result = dmalloc_malloc(file, line, size, DMALLOC_FUNC_MALLOC, 0, 0);
#else
result = malloc(size);
#endif
if (PREDICT_UNLIKELY(result == NULL)) {
log_err(LD_MM,"Out of memory on malloc(). Dying.");
/* If these functions die within a worker process, they won't call
* spawn_exit, but that's ok, since the parent will run out of memory soon
* anyway. */
exit(1);
}
return result;
}
/** Allocate a chunk of <b>size</b> bytes of memory, fill the memory with
* zero bytes, and return a pointer to the result. Log and terminate
* the process on error. (Same as calloc(size,1), but never returns NULL.)
*/
void *
_tor_malloc_zero(size_t size DMALLOC_PARAMS)
{
/* You may ask yourself, "wouldn't it be smart to use calloc instead of
* malloc+memset? Perhaps libc's calloc knows some nifty optimization trick
* we don't!" Indeed it does, but its optimizations are only a big win when
* we're allocating something very big (it knows if it just got the memory
* from the OS in a pre-zeroed state). We don't want to use tor_malloc_zero
* for big stuff, so we don't bother with calloc. */
void *result = _tor_malloc(size DMALLOC_FN_ARGS);
memset(result, 0, size);
return result;
}
/** Change the size of the memory block pointed to by <b>ptr</b> to <b>size</b>
* bytes long; return the new memory block. On error, log and
* terminate. (Like realloc(ptr,size), but never returns NULL.)
*/
void *
_tor_realloc(void *ptr, size_t size DMALLOC_PARAMS)
{
void *result;
#ifdef USE_DMALLOC
result = dmalloc_realloc(file, line, ptr, size, DMALLOC_FUNC_REALLOC, 0);
#else
result = realloc(ptr, size);
#endif
if (PREDICT_UNLIKELY(result == NULL)) {
log_err(LD_MM,"Out of memory on realloc(). Dying.");
exit(1);
}
return result;
}
/** Return a newly allocated copy of the NUL-terminated string s. On
* error, log and terminate. (Like strdup(s), but never returns
* NULL.)
*/
char *
_tor_strdup(const char *s DMALLOC_PARAMS)
{
char *dup;
tor_assert(s);
#ifdef USE_DMALLOC
dup = dmalloc_strdup(file, line, s, 0);
#else
dup = strdup(s);
#endif
if (PREDICT_UNLIKELY(dup == NULL)) {
log_err(LD_MM,"Out of memory on strdup(). Dying.");
exit(1);
}
return dup;
}
/** Allocate and return a new string containing the first <b>n</b>
* characters of <b>s</b>. If <b>s</b> is longer than <b>n</b>
* characters, only the first <b>n</b> are copied. The result is
* always NUL-terminated. (Like strndup(s,n), but never returns
* NULL.)
*/
char *
_tor_strndup(const char *s, size_t n DMALLOC_PARAMS)
{
char *dup;
tor_assert(s);
dup = _tor_malloc((n+1) DMALLOC_FN_ARGS);
/* Performance note: Ordinarily we prefer strlcpy to strncpy. But
* this function gets called a whole lot, and platform strncpy is
* much faster than strlcpy when strlen(s) is much longer than n.
*/
strncpy(dup, s, n);
dup[n]='\0';
return dup;
}
/** Allocate a chunk of <b>len</b> bytes, with the same contents as the
* <b>len</b> bytes starting at <b>mem</b>. */
void *
_tor_memdup(const void *mem, size_t len DMALLOC_PARAMS)
{
char *dup;
tor_assert(mem);
dup = _tor_malloc(len DMALLOC_FN_ARGS);
memcpy(dup, mem, len);
return dup;
}
/** Helper for places that need to take a function pointer to the right
* spelling of "free()". */
void
_tor_free(void *mem)
{
tor_free(mem);
}
#if defined(HAVE_MALLOC_GOOD_SIZE) && !defined(HAVE_MALLOC_GOOD_SIZE_PROTOTYPE)
/* Some version of Mac OSX have malloc_good_size in their libc, but not
* actually defined in malloc/malloc.h. We detect this and work around it by
* prototyping.
*/
extern size_t malloc_good_size(size_t size);
#endif
/** Allocate and return a chunk of memory of size at least *<b>size</b>, using
* the same resources we would use to malloc *<b>sizep</b>. Set *<b>sizep</b>
* to the number of usable bytes in the chunk of memory. */
void *
_tor_malloc_roundup(size_t *sizep DMALLOC_PARAMS)
{
#ifdef HAVE_MALLOC_GOOD_SIZE
*sizep = malloc_good_size(*sizep);
return _tor_malloc(*sizep DMALLOC_FN_ARGS);
#elif 0 && defined(HAVE_MALLOC_USABLE_SIZE) && !defined(USE_DMALLOC)
/* Never use malloc_usable_size(); it makes valgrind really unhappy,
* and doesn't win much in terms of usable space where it exists. */
void *result = _tor_malloc(*sizep DMALLOC_FN_ARGS);
*sizep = malloc_usable_size(result);
return result;
#else
return _tor_malloc(*sizep DMALLOC_FN_ARGS);
#endif
}
/** Call the platform malloc info function, and dump the results to the log at
* level <b>severity</b>. If no such function exists, do nothing. */
void
tor_log_mallinfo(int severity)
{
#ifdef HAVE_MALLINFO
struct mallinfo mi;
memset(&mi, 0, sizeof(mi));
mi = mallinfo();
tor_log(severity, LD_MM,
"mallinfo() said: arena=%d, ordblks=%d, smblks=%d, hblks=%d, "
"hblkhd=%d, usmblks=%d, fsmblks=%d, uordblks=%d, fordblks=%d, "
"keepcost=%d",
mi.arena, mi.ordblks, mi.smblks, mi.hblks,
mi.hblkhd, mi.usmblks, mi.fsmblks, mi.uordblks, mi.fordblks,
mi.keepcost);
#else
(void)severity;
#endif
#ifdef USE_DMALLOC
dmalloc_log_changed(0, /* Since the program started. */
1, /* Log info about non-freed pointers. */
0, /* Do not log info about freed pointers. */
0 /* Do not log individual pointers. */
);
#endif
}
/* =====
* Math
* ===== */
/**
* Returns the natural logarithm of d base 2. We define this wrapper here so
* as to make it easier not to conflict with Tor's log() macro.
*/
double
tor_mathlog(double d)
{
return log(d);
}
/** Return the long integer closest to d. We define this wrapper here so
* that not all users of math.h need to use the right incancations to get
* the c99 functions. */
long
tor_lround(double d)
{
return lround(d);
}
/** Returns floor(log2(u64)). If u64 is 0, (incorrectly) returns 0. */
int
tor_log2(uint64_t u64)
{
int r = 0;
if (u64 >= (U64_LITERAL(1)<<32)) {
u64 >>= 32;
r = 32;
}
if (u64 >= (U64_LITERAL(1)<<16)) {
u64 >>= 16;
r += 16;
}
if (u64 >= (U64_LITERAL(1)<<8)) {
u64 >>= 8;
r += 8;
}
if (u64 >= (U64_LITERAL(1)<<4)) {
u64 >>= 4;
r += 4;
}
if (u64 >= (U64_LITERAL(1)<<2)) {
u64 >>= 2;
r += 2;
}
if (u64 >= (U64_LITERAL(1)<<1)) {
u64 >>= 1;
r += 1;
}
return r;
}
/** Return the power of 2 closest to <b>u64</b>. */
uint64_t
round_to_power_of_2(uint64_t u64)
{
int lg2 = tor_log2(u64);
uint64_t low = U64_LITERAL(1) << lg2, high = U64_LITERAL(1) << (lg2+1);
if (high - u64 < u64 - low)
return high;
else
return low;
}
/** Return the lowest x such that x is at least <b>number</b>, and x modulo
* <b>divisor</b> == 0. */
unsigned
round_to_next_multiple_of(unsigned number, unsigned divisor)
{
number += divisor - 1;
number -= number % divisor;
return number;
}
/** Return the lowest x such that x is at least <b>number</b>, and x modulo
* <b>divisor</b> == 0. */
uint32_t
round_uint32_to_next_multiple_of(uint32_t number, uint32_t divisor)
{
number += divisor - 1;
number -= number % divisor;
return number;
}
/** Return the lowest x such that x is at least <b>number</b>, and x modulo
* <b>divisor</b> == 0. */
uint64_t
round_uint64_to_next_multiple_of(uint64_t number, uint64_t divisor)
{
number += divisor - 1;
number -= number % divisor;
return number;
}
/* =====
* String manipulation
* ===== */
/** Remove from the string <b>s</b> every character which appears in
* <b>strip</b>. */
void
tor_strstrip(char *s, const char *strip)
{
char *read = s;
while (*read) {
if (strchr(strip, *read)) {
++read;
} else {
*s++ = *read++;
}
}
*s = '\0';
}
/** Return a pointer to a NUL-terminated hexadecimal string encoding
* the first <b>fromlen</b> bytes of <b>from</b>. (fromlen must be \<= 32.) The
* result does not need to be deallocated, but repeated calls to
* hex_str will trash old results.
*/
const char *
hex_str(const char *from, size_t fromlen)
{
static char buf[65];
if (fromlen>(sizeof(buf)-1)/2)
fromlen = (sizeof(buf)-1)/2;
base16_encode(buf,sizeof(buf),from,fromlen);
return buf;
}
/** Convert all alphabetic characters in the nul-terminated string <b>s</b> to
* lowercase. */
void
tor_strlower(char *s)
{
while (*s) {
*s = TOR_TOLOWER(*s);
++s;
}
}
/** Convert all alphabetic characters in the nul-terminated string <b>s</b> to
* lowercase. */
void
tor_strupper(char *s)
{
while (*s) {
*s = TOR_TOUPPER(*s);
++s;
}
}
/** Return 1 if every character in <b>s</b> is printable, else return 0.
*/
int
tor_strisprint(const char *s)
{
while (*s) {
if (!TOR_ISPRINT(*s))
return 0;
s++;
}
return 1;
}
/** Return 1 if no character in <b>s</b> is uppercase, else return 0.
*/
int
tor_strisnonupper(const char *s)
{
while (*s) {
if (TOR_ISUPPER(*s))
return 0;
s++;
}
return 1;
}
/** Compares the first strlen(s2) characters of s1 with s2. Returns as for
* strcmp.
*/
int
strcmpstart(const char *s1, const char *s2)
{
size_t n = strlen(s2);
return strncmp(s1, s2, n);
}
/** Compare the s1_len-byte string <b>s1</b> with <b>s2</b>,
* without depending on a terminating nul in s1. Sorting order is first by
* length, then lexically; return values are as for strcmp.
*/
int
strcmp_len(const char *s1, const char *s2, size_t s1_len)
{
size_t s2_len = strlen(s2);
if (s1_len < s2_len)
return -1;
if (s1_len > s2_len)
return 1;
return memcmp(s1, s2, s2_len);
}
/** Compares the first strlen(s2) characters of s1 with s2. Returns as for
* strcasecmp.
*/
int
strcasecmpstart(const char *s1, const char *s2)
{
size_t n = strlen(s2);
return strncasecmp(s1, s2, n);
}
/** Compares the last strlen(s2) characters of s1 with s2. Returns as for
* strcmp.
*/
int
strcmpend(const char *s1, const char *s2)
{
size_t n1 = strlen(s1), n2 = strlen(s2);
if (n2>n1)
return strcmp(s1,s2);
else
return strncmp(s1+(n1-n2), s2, n2);
}
/** Compares the last strlen(s2) characters of s1 with s2. Returns as for
* strcasecmp.
*/
int
strcasecmpend(const char *s1, const char *s2)
{
size_t n1 = strlen(s1), n2 = strlen(s2);
if (n2>n1) /* then they can't be the same; figure out which is bigger */
return strcasecmp(s1,s2);
else
return strncasecmp(s1+(n1-n2), s2, n2);
}
/** Compare the value of the string <b>prefix</b> with the start of the
* <b>memlen</b>-byte memory chunk at <b>mem</b>. Return as for strcmp.
*
* [As memcmp(mem, prefix, strlen(prefix)) but returns -1 if memlen is less
* than strlen(prefix).]
*/
int
memcmpstart(const void *mem, size_t memlen,
const char *prefix)
{
size_t plen = strlen(prefix);
if (memlen < plen)
return -1;
return memcmp(mem, prefix, plen);
}
/** Return a pointer to the first char of s that is not whitespace and
* not a comment, or to the terminating NUL if no such character exists.
*/
const char *
eat_whitespace(const char *s)
{
tor_assert(s);
while (1) {
switch (*s) {
case '\0':
default:
return s;
case ' ':
case '\t':
case '\n':
case '\r':
++s;
break;
case '#':
++s;
while (*s && *s != '\n')
++s;
}
}
}
/** Return a pointer to the first char of s that is not whitespace and
* not a comment, or to the terminating NUL if no such character exists.
*/
const char *
eat_whitespace_eos(const char *s, const char *eos)
{
tor_assert(s);
tor_assert(eos && s <= eos);
while (s < eos) {
switch (*s) {
case '\0':
default:
return s;
case ' ':
case '\t':
case '\n':
case '\r':
++s;
break;
case '#':
++s;
while (s < eos && *s && *s != '\n')
++s;
}
}
return s;
}
/** Return a pointer to the first char of s that is not a space or a tab
* or a \\r, or to the terminating NUL if no such character exists. */
const char *
eat_whitespace_no_nl(const char *s)
{
while (*s == ' ' || *s == '\t' || *s == '\r')
++s;
return s;
}
/** As eat_whitespace_no_nl, but stop at <b>eos</b> whether we have
* found a non-whitespace character or not. */
const char *
eat_whitespace_eos_no_nl(const char *s, const char *eos)
{
while (s < eos && (*s == ' ' || *s == '\t' || *s == '\r'))
++s;
return s;
}
/** Return a pointer to the first char of s that is whitespace or <b>#</b>,
* or to the terminating NUL if no such character exists.
*/
const char *
find_whitespace(const char *s)
{
/* tor_assert(s); */
while (1) {
switch (*s)
{
case '\0':
case '#':
case ' ':
case '\r':
case '\n':
case '\t':
return s;
default:
++s;
}
}
}
/** As find_whitespace, but stop at <b>eos</b> whether we have found a
* whitespace or not. */
const char *
find_whitespace_eos(const char *s, const char *eos)
{
/* tor_assert(s); */
while (s < eos) {
switch (*s)
{
case '\0':
case '#':
case ' ':
case '\r':
case '\n':
case '\t':
return s;
default:
++s;
}
}
return s;
}
/** Return the first occurrence of <b>needle</b> in <b>haystack</b> that
* occurs at the start of a line (that is, at the beginning of <b>haystack</b>
* or immediately after a newline). Return NULL if no such string is found.
*/
const char *
find_str_at_start_of_line(const char *haystack, const char *needle)
{
size_t needle_len = strlen(needle);
do {
if (!strncmp(haystack, needle, needle_len))
return haystack;
haystack = strchr(haystack, '\n');
if (!haystack)
return NULL;
else
++haystack;
} while (*haystack);
return NULL;
}
/** Return true iff the 'len' bytes at 'mem' are all zero. */
int
tor_mem_is_zero(const char *mem, size_t len)
{
static const char ZERO[] = {
0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
};
while (len >= sizeof(ZERO)) {
if (memcmp(mem, ZERO, sizeof(ZERO)))
return 0;
len -= sizeof(ZERO);
mem += sizeof(ZERO);
}
/* Deal with leftover bytes. */
if (len)
return ! memcmp(mem, ZERO, len);
return 1;
}
/** Return true iff the DIGEST_LEN bytes in digest are all zero. */
int
tor_digest_is_zero(const char *digest)
{
return tor_mem_is_zero(digest, DIGEST_LEN);
}
/** Return true iff the DIGEST256_LEN bytes in digest are all zero. */
int
tor_digest256_is_zero(const char *digest)
{
return tor_mem_is_zero(digest, DIGEST256_LEN);
}
/* Helper: common code to check whether the result of a strtol or strtoul or
* strtoll is correct. */
#define CHECK_STRTOX_RESULT() \
/* Was at least one character converted? */ \
if (endptr == s) \
goto err; \
/* Were there unexpected unconverted characters? */ \
if (!next && *endptr) \
goto err; \
/* Is r within limits? */ \
if (r < min || r > max) \
goto err; \
if (ok) *ok = 1; \
if (next) *next = endptr; \
return r; \
err: \
if (ok) *ok = 0; \
if (next) *next = endptr; \
return 0
/** Extract a long from the start of s, in the given numeric base. If
* there is unconverted data and next is provided, set *next to the
* first unconverted character. An error has occurred if no characters
* are converted; or if there are unconverted characters and next is NULL; or
* if the parsed value is not between min and max. When no error occurs,
* return the parsed value and set *ok (if provided) to 1. When an error
* occurs, return 0 and set *ok (if provided) to 0.
*/
long
tor_parse_long(const char *s, int base, long min, long max,
int *ok, char **next)
{
char *endptr;
long r;
r = strtol(s, &endptr, base);
CHECK_STRTOX_RESULT();
}
/** As tor_parse_long(), but return an unsigned long. */
unsigned long
tor_parse_ulong(const char *s, int base, unsigned long min,
unsigned long max, int *ok, char **next)
{
char *endptr;
unsigned long r;
r = strtoul(s, &endptr, base);
CHECK_STRTOX_RESULT();
}
/** As tor_parse_long(), but return a double. */
double
tor_parse_double(const char *s, double min, double max, int *ok, char **next)
{
char *endptr;
double r;
r = strtod(s, &endptr);
CHECK_STRTOX_RESULT();
}
/** As tor_parse_long, but return a uint64_t. Only base 10 is guaranteed to
* work for now. */
uint64_t
tor_parse_uint64(const char *s, int base, uint64_t min,
uint64_t max, int *ok, char **next)
{
char *endptr;
uint64_t r;
#ifdef HAVE_STRTOULL
r = (uint64_t)strtoull(s, &endptr, base);
#elif defined(MS_WINDOWS)
#if defined(_MSC_VER) && _MSC_VER < 1300
tor_assert(base <= 10);
r = (uint64_t)_atoi64(s);
endptr = (char*)s;
while (TOR_ISSPACE(*endptr)) endptr++;
while (TOR_ISDIGIT(*endptr)) endptr++;
#else
r = (uint64_t)_strtoui64(s, &endptr, base);
#endif
#elif SIZEOF_LONG == 8
r = (uint64_t)strtoul(s, &endptr, base);
#else
#error "I don't know how to parse 64-bit numbers."
#endif
CHECK_STRTOX_RESULT();
}
/** Encode the <b>srclen</b> bytes at <b>src</b> in a NUL-terminated,
* uppercase hexadecimal string; store it in the <b>destlen</b>-byte buffer
* <b>dest</b>.
*/
void
base16_encode(char *dest, size_t destlen, const char *src, size_t srclen)
{
const char *end;
char *cp;
tor_assert(destlen >= srclen*2+1);
tor_assert(destlen < SIZE_T_CEILING);
cp = dest;
end = src+srclen;
while (src<end) {
*cp++ = "0123456789ABCDEF"[ (*(const uint8_t*)src) >> 4 ];
*cp++ = "0123456789ABCDEF"[ (*(const uint8_t*)src) & 0xf ];
++src;
}
*cp = '\0';
}
/** Helper: given a hex digit, return its value, or -1 if it isn't hex. */
static INLINE int
_hex_decode_digit(char c)
{
switch (c) {
case '0': return 0;
case '1': return 1;
case '2': return 2;
case '3': return 3;
case '4': return 4;
case '5': return 5;
case '6': return 6;
case '7': return 7;
case '8': return 8;
case '9': return 9;
case 'A': case 'a': return 10;
case 'B': case 'b': return 11;
case 'C': case 'c': return 12;
case 'D': case 'd': return 13;
case 'E': case 'e': return 14;
case 'F': case 'f': return 15;
default:
return -1;
}
}
/** Helper: given a hex digit, return its value, or -1 if it isn't hex. */
int
hex_decode_digit(char c)
{
return _hex_decode_digit(c);
}
/** Given a hexadecimal string of <b>srclen</b> bytes in <b>src</b>, decode it
* and store the result in the <b>destlen</b>-byte buffer at <b>dest</b>.
* Return 0 on success, -1 on failure. */
int
base16_decode(char *dest, size_t destlen, const char *src, size_t srclen)
{
const char *end;
int v1,v2;
if ((srclen % 2) != 0)
return -1;
if (destlen < srclen/2 || destlen > SIZE_T_CEILING)
return -1;
end = src+srclen;
while (src<end) {
v1 = _hex_decode_digit(*src);
v2 = _hex_decode_digit(*(src+1));
if (v1<0||v2<0)
return -1;
*(uint8_t*)dest = (v1<<4)|v2;
++dest;
src+=2;
}
return 0;
}
/** Allocate and return a new string representing the contents of <b>s</b>,
* surrounded by quotes and using standard C escapes.
*
* Generally, we use this for logging values that come in over the network to
* keep them from tricking users, and for sending certain values to the
* controller.
*
* We trust values from the resolver, OS, configuration file, and command line
* to not be maliciously ill-formed. We validate incoming routerdescs and
* SOCKS requests and addresses from BEGIN cells as they're parsed;
* afterwards, we trust them as non-malicious.
*/
char *
esc_for_log(const char *s)
{
const char *cp;
char *result, *outp;
size_t len = 3;
if (!s) {
return tor_strdup("");
}
for (cp = s; *cp; ++cp) {
switch (*cp) {
case '\\':
case '\"':
case '\'':
case '\r':
case '\n':
case '\t':
len += 2;
break;
default:
if (TOR_ISPRINT(*cp) && ((uint8_t)*cp)<127)
++len;
else
len += 4;
break;
}
}
result = outp = tor_malloc(len);
*outp++ = '\"';
for (cp = s; *cp; ++cp) {
switch (*cp) {
case '\\':
case '\"':
case '\'':
*outp++ = '\\';
*outp++ = *cp;
break;
case '\n':
*outp++ = '\\';
*outp++ = 'n';
break;
case '\t':
*outp++ = '\\';
*outp++ = 't';
break;
case '\r':
*outp++ = '\\';
*outp++ = 'r';
break;
default:
if (TOR_ISPRINT(*cp) && ((uint8_t)*cp)<127) {
*outp++ = *cp;
} else {
tor_snprintf(outp, 5, "\\%03o", (int)(uint8_t) *cp);
outp += 4;
}
break;
}
}
*outp++ = '\"';
*outp++ = 0;
return result;
}
/** Allocate and return a new string representing the contents of <b>s</b>,
* surrounded by quotes and using standard C escapes.
*
* THIS FUNCTION IS NOT REENTRANT. Don't call it from outside the main
* thread. Also, each call invalidates the last-returned value, so don't
* try log_warn(LD_GENERAL, "%s %s", escaped(a), escaped(b));
*/
const char *
escaped(const char *s)
{
static char *_escaped_val = NULL;
tor_free(_escaped_val);
if (s)
_escaped_val = esc_for_log(s);
else
_escaped_val = NULL;
return _escaped_val;
}
/** Rudimentary string wrapping code: given a un-wrapped <b>string</b> (no
* newlines!), break the string into newline-terminated lines of no more than
* <b>width</b> characters long (not counting newline) and insert them into
* <b>out</b> in order. Precede the first line with prefix0, and subsequent
* lines with prefixRest.
*/
/* This uses a stupid greedy wrapping algorithm right now:
* - For each line:
* - Try to fit as much stuff as possible, but break on a space.
* - If the first "word" of the line will extend beyond the allowable
* width, break the word at the end of the width.
*/
void
wrap_string(smartlist_t *out, const char *string, size_t width,
const char *prefix0, const char *prefixRest)
{
size_t p0Len, pRestLen, pCurLen;
const char *eos, *prefixCur;
tor_assert(out);
tor_assert(string);
tor_assert(width);
if (!prefix0)
prefix0 = "";
if (!prefixRest)
prefixRest = "";
p0Len = strlen(prefix0);
pRestLen = strlen(prefixRest);
tor_assert(width > p0Len && width > pRestLen);
eos = strchr(string, '\0');
tor_assert(eos);
pCurLen = p0Len;
prefixCur = prefix0;
while ((eos-string)+pCurLen > width) {
const char *eol = string + width - pCurLen;
while (eol > string && *eol != ' ')
--eol;
/* eol is now the last space that can fit, or the start of the string. */
if (eol > string) {
size_t line_len = (eol-string) + pCurLen + 2;
char *line = tor_malloc(line_len);
memcpy(line, prefixCur, pCurLen);
memcpy(line+pCurLen, string, eol-string);
line[line_len-2] = '\n';
line[line_len-1] = '\0';
smartlist_add(out, line);
string = eol + 1;
} else {
size_t line_len = width + 2;
char *line = tor_malloc(line_len);
memcpy(line, prefixCur, pCurLen);
memcpy(line+pCurLen, string, width - pCurLen);
line[line_len-2] = '\n';
line[line_len-1] = '\0';
smartlist_add(out, line);
string += width-pCurLen;
}
prefixCur = prefixRest;
pCurLen = pRestLen;
}
if (string < eos) {
size_t line_len = (eos-string) + pCurLen + 2;
char *line = tor_malloc(line_len);
memcpy(line, prefixCur, pCurLen);
memcpy(line+pCurLen, string, eos-string);
line[line_len-2] = '\n';
line[line_len-1] = '\0';
smartlist_add(out, line);
}
}
/* =====
* Time
* ===== */
/**
* Converts struct timeval to a double value.
* Preserves microsecond precision, but just barely.
* Error is approx +/- 0.1 usec when dealing with epoch values.
*/
double
tv_to_double(const struct timeval *tv)
{
double conv = tv->tv_sec;
conv += tv->tv_usec/1000000.0;
return conv;
}
/**
* Converts timeval to milliseconds.
*/
int64_t
tv_to_msec(const struct timeval *tv)
{
int64_t conv = ((int64_t)tv->tv_sec)*1000L;
/* Round ghetto-style */
conv += ((int64_t)tv->tv_usec+500)/1000L;
return conv;
}
/**
* Converts timeval to microseconds.
*/
int64_t
tv_to_usec(const struct timeval *tv)
{
int64_t conv = ((int64_t)tv->tv_sec)*1000000L;
conv += tv->tv_usec;
return conv;
}
/** Return the number of microseconds elapsed between *start and *end.
*/
long
tv_udiff(const struct timeval *start, const struct timeval *end)
{
long udiff;
long secdiff = end->tv_sec - start->tv_sec;
if (labs(secdiff+1) > LONG_MAX/1000000) {
log_warn(LD_GENERAL, "comparing times on microsecond detail too far "
"apart: %ld seconds", secdiff);
return LONG_MAX;
}
udiff = secdiff*1000000L + (end->tv_usec - start->tv_usec);
return udiff;
}
/** Return the number of milliseconds elapsed between *start and *end.
*/
long
tv_mdiff(const struct timeval *start, const struct timeval *end)
{
long mdiff;
long secdiff = end->tv_sec - start->tv_sec;
if (labs(secdiff+1) > LONG_MAX/1000) {
log_warn(LD_GENERAL, "comparing times on millisecond detail too far "
"apart: %ld seconds", secdiff);
return LONG_MAX;
}
/* Subtract and round */
mdiff = secdiff*1000L +
((long)end->tv_usec - (long)start->tv_usec + 500L) / 1000L;
return mdiff;
}
/** Yield true iff <b>y</b> is a leap-year. */
#define IS_LEAPYEAR(y) (!(y % 4) && ((y % 100) || !(y % 400)))
/** Helper: Return the number of leap-days between Jan 1, y1 and Jan 1, y2. */
static int
n_leapdays(int y1, int y2)
{
--y1;
--y2;
return (y2/4 - y1/4) - (y2/100 - y1/100) + (y2/400 - y1/400);
}
/** Number of days per month in non-leap year; used by tor_timegm. */
static const int days_per_month[] =
{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
/** Return a time_t given a struct tm. The result is given in GMT, and
* does not account for leap seconds.
*/
time_t
tor_timegm(struct tm *tm)
{
/* This is a pretty ironclad timegm implementation, snarfed from Python2.2.
* It's way more brute-force than fiddling with tzset().
*/
time_t year, days, hours, minutes, seconds;
int i;
year = tm->tm_year + 1900;
if (year < 1970 || tm->tm_mon < 0 || tm->tm_mon > 11) {
log_warn(LD_BUG, "Out-of-range argument to tor_timegm");
return -1;
}
tor_assert(year < INT_MAX);
days = 365 * (year-1970) + n_leapdays(1970,(int)year);
for (i = 0; i < tm->tm_mon; ++i)
days += days_per_month[i];
if (tm->tm_mon > 1 && IS_LEAPYEAR(year))
++days;
days += tm->tm_mday - 1;
hours = days*24 + tm->tm_hour;
minutes = hours*60 + tm->tm_min;
seconds = minutes*60 + tm->tm_sec;
return seconds;
}
/* strftime is locale-specific, so we need to replace those parts */
/** A c-locale array of 3-letter names of weekdays, starting with Sun. */
static const char *WEEKDAY_NAMES[] =
{ "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };
/** A c-locale array of 3-letter names of months, starting with Jan. */
static const char *MONTH_NAMES[] =
{ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
/** Set <b>buf</b> to the RFC1123 encoding of the GMT value of <b>t</b>.
* The buffer must be at least RFC1123_TIME_LEN+1 bytes long.
*
* (RFC1123 format is Fri, 29 Sep 2006 15:54:20 GMT)
*/
void
format_rfc1123_time(char *buf, time_t t)
{
struct tm tm;
tor_gmtime_r(&t, &tm);
strftime(buf, RFC1123_TIME_LEN+1, "___, %d ___ %Y %H:%M:%S GMT", &tm);
tor_assert(tm.tm_wday >= 0);
tor_assert(tm.tm_wday <= 6);
memcpy(buf, WEEKDAY_NAMES[tm.tm_wday], 3);
tor_assert(tm.tm_wday >= 0);
tor_assert(tm.tm_mon <= 11);
memcpy(buf+8, MONTH_NAMES[tm.tm_mon], 3);
}
/** Parse the RFC1123 encoding of some time (in GMT) from <b>buf</b>,
* and store the result in *<b>t</b>.
*
* Return 0 on success, -1 on failure.
*/
int
parse_rfc1123_time(const char *buf, time_t *t)
{
struct tm tm;
char month[4];
char weekday[4];
int i, m;
unsigned tm_mday, tm_year, tm_hour, tm_min, tm_sec;
if (strlen(buf) != RFC1123_TIME_LEN)
return -1;
memset(&tm, 0, sizeof(tm));
if (tor_sscanf(buf, "%3s, %2u %3s %u %2u:%2u:%2u GMT", weekday,
&tm_mday, month, &tm_year, &tm_hour,
&tm_min, &tm_sec) < 7) {
char *esc = esc_for_log(buf);
log_warn(LD_GENERAL, "Got invalid RFC1123 time %s", esc);
tor_free(esc);
return -1;
}
if (tm_mday > 31 || tm_hour > 23 || tm_min > 59 || tm_sec > 61) {
char *esc = esc_for_log(buf);
log_warn(LD_GENERAL, "Got invalid RFC1123 time %s", esc);
tor_free(esc);
return -1;
}
tm.tm_mday = (int)tm_mday;
tm.tm_year = (int)tm_year;
tm.tm_hour = (int)tm_hour;
tm.tm_min = (int)tm_min;
tm.tm_sec = (int)tm_sec;
m = -1;
for (i = 0; i < 12; ++i) {
if (!strcmp(month, MONTH_NAMES[i])) {
m = i;
break;
}
}
if (m<0) {
char *esc = esc_for_log(buf);
log_warn(LD_GENERAL, "Got invalid RFC1123 time %s: No such month", esc);
tor_free(esc);
return -1;
}
tm.tm_mon = m;
if (tm.tm_year < 1970) {
char *esc = esc_for_log(buf);
log_warn(LD_GENERAL,
"Got invalid RFC1123 time %s. (Before 1970)", esc);
tor_free(esc);
return -1;
}
tm.tm_year -= 1900;
*t = tor_timegm(&tm);
return 0;
}
/** Set <b>buf</b> to the ISO8601 encoding of the local value of <b>t</b>.
* The buffer must be at least ISO_TIME_LEN+1 bytes long.
*
* (ISO8601 format is 2006-10-29 10:57:20)
*/
void
format_local_iso_time(char *buf, time_t t)
{
struct tm tm;
strftime(buf, ISO_TIME_LEN+1, "%Y-%m-%d %H:%M:%S", tor_localtime_r(&t, &tm));
}
/** Set <b>buf</b> to the ISO8601 encoding of the GMT value of <b>t</b>.
* The buffer must be at least ISO_TIME_LEN+1 bytes long.
*/
void
format_iso_time(char *buf, time_t t)
{
struct tm tm;
strftime(buf, ISO_TIME_LEN+1, "%Y-%m-%d %H:%M:%S", tor_gmtime_r(&t, &tm));
}
/** Given an ISO-formatted UTC time value (after the epoch) in <b>cp</b>,
* parse it and store its value in *<b>t</b>. Return 0 on success, -1 on
* failure. Ignore extraneous stuff in <b>cp</b> separated by whitespace from
* the end of the time string. */
int
parse_iso_time(const char *cp, time_t *t)
{
struct tm st_tm;
unsigned int year=0, month=0, day=0, hour=100, minute=100, second=100;
if (tor_sscanf(cp, "%u-%2u-%2u %2u:%2u:%2u", &year, &month,
&day, &hour, &minute, &second) < 6) {
char *esc = esc_for_log(cp);
log_warn(LD_GENERAL, "ISO time %s was unparseable", esc);
tor_free(esc);
return -1;
}
if (year < 1970 || month < 1 || month > 12 || day < 1 || day > 31 ||
hour > 23 || minute > 59 || second > 61) {
char *esc = esc_for_log(cp);
log_warn(LD_GENERAL, "ISO time %s was nonsensical", esc);
tor_free(esc);
return -1;
}
st_tm.tm_year = year-1900;
st_tm.tm_mon = month-1;
st_tm.tm_mday = day;
st_tm.tm_hour = hour;
st_tm.tm_min = minute;
st_tm.tm_sec = second;
if (st_tm.tm_year < 70) {
char *esc = esc_for_log(cp);
log_warn(LD_GENERAL, "Got invalid ISO time %s. (Before 1970)", esc);
tor_free(esc);
return -1;
}
*t = tor_timegm(&st_tm);
return 0;
}
/** Given a <b>date</b> in one of the three formats allowed by HTTP (ugh),
* parse it into <b>tm</b>. Return 0 on success, negative on failure. */
int
parse_http_time(const char *date, struct tm *tm)
{
const char *cp;
char month[4];
char wkday[4];
int i;
unsigned tm_mday, tm_year, tm_hour, tm_min, tm_sec;
tor_assert(tm);
memset(tm, 0, sizeof(*tm));
/* First, try RFC1123 or RFC850 format: skip the weekday. */
if ((cp = strchr(date, ','))) {
++cp;
if (tor_sscanf(date, "%2u %3s %4u %2u:%2u:%2u GMT",
&tm_mday, month, &tm_year,
&tm_hour, &tm_min, &tm_sec) == 6) {
/* rfc1123-date */
tm_year -= 1900;
} else if (tor_sscanf(date, "%2u-%3s-%2u %2u:%2u:%2u GMT",
&tm_mday, month, &tm_year,
&tm_hour, &tm_min, &tm_sec) == 6) {
/* rfc850-date */
} else {
return -1;
}
} else {
/* No comma; possibly asctime() format. */
if (tor_sscanf(date, "%3s %3s %2u %2u:%2u:%2u %4u",
wkday, month, &tm_mday,
&tm_hour, &tm_min, &tm_sec, &tm_year) == 7) {
tm_year -= 1900;
} else {
return -1;
}
}
tm->tm_mday = (int)tm_mday;
tm->tm_year = (int)tm_year;
tm->tm_hour = (int)tm_hour;
tm->tm_min = (int)tm_min;
tm->tm_sec = (int)tm_sec;
month[3] = '\0';
/* Okay, now decode the month. */
for (i = 0; i < 12; ++i) {
if (!strcasecmp(MONTH_NAMES[i], month)) {
tm->tm_mon = i+1;
}
}
if (tm->tm_year < 0 ||
tm->tm_mon < 1 || tm->tm_mon > 12 ||
tm->tm_mday < 0 || tm->tm_mday > 31 ||
tm->tm_hour < 0 || tm->tm_hour > 23 ||
tm->tm_min < 0 || tm->tm_min > 59 ||
tm->tm_sec < 0 || tm->tm_sec > 61)
return -1; /* Out of range, or bad month. */
return 0;
}
/** Given an <b>interval</b> in seconds, try to write it to the
* <b>out_len</b>-byte buffer in <b>out</b> in a human-readable form.
* Return 0 on success, -1 on failure.
*/
int
format_time_interval(char *out, size_t out_len, long interval)
{
/* We only report seconds if there's no hours. */
long sec = 0, min = 0, hour = 0, day = 0;
if (interval < 0)
interval = -interval;
if (interval >= 86400) {
day = interval / 86400;
interval %= 86400;
}
if (interval >= 3600) {
hour = interval / 3600;
interval %= 3600;
}
if (interval >= 60) {
min = interval / 60;
interval %= 60;
}
sec = interval;
if (day) {
return tor_snprintf(out, out_len, "%ld days, %ld hours, %ld minutes",
day, hour, min);
} else if (hour) {
return tor_snprintf(out, out_len, "%ld hours, %ld minutes", hour, min);
} else if (min) {
return tor_snprintf(out, out_len, "%ld minutes, %ld seconds", min, sec);
} else {
return tor_snprintf(out, out_len, "%ld seconds", sec);
}
}
/* =====
* Cached time
* ===== */
#ifndef TIME_IS_FAST
/** Cached estimate of the current time. Updated around once per second;
* may be a few seconds off if we are really busy. This is a hack to avoid
* calling time(NULL) (which not everybody has optimized) on critical paths.
*/
static time_t cached_approx_time = 0;
/** Return a cached estimate of the current time from when
* update_approx_time() was last called. This is a hack to avoid calling
* time(NULL) on critical paths: please do not even think of calling it
* anywhere else. */
time_t
approx_time(void)
{
return cached_approx_time;
}
/** Update the cached estimate of the current time. This function SHOULD be
* called once per second, and MUST be called before the first call to
* get_approx_time. */
void
update_approx_time(time_t now)
{
cached_approx_time = now;
}
#endif
/* =====
* Fuzzy time
* XXXX022 Use this consistently or rip most of it out.
* ===== */
/* In a perfect world, everybody would run NTP, and NTP would be perfect, so
* if we wanted to know "Is the current time before time X?" we could just say
* "time(NULL) < X".
*
* But unfortunately, many users are running Tor in an imperfect world, on
* even more imperfect computers. Hence, we need to track time oddly. We
* model the user's computer as being "skewed" from accurate time by
* -<b>ftime_skew</b> seconds, such that our best guess of the current time is
* time(NULL)+ftime_skew. We also assume that our measurements of time may
* have up to <b>ftime_slop</b> seconds of inaccuracy; IOW, our window of
* estimate for the current time is now + ftime_skew +/- ftime_slop.
*/
/** Our current estimate of our skew, such that we think the current time is
* closest to time(NULL)+ftime_skew. */
static int ftime_skew = 0;
/** Tolerance during time comparisons, in seconds. */
static int ftime_slop = 60;
/** Set the largest amount of sloppiness we'll allow in fuzzy time
* comparisons. */
void
ftime_set_maximum_sloppiness(int seconds)
{
tor_assert(seconds >= 0);
ftime_slop = seconds;
}
/** Set the amount by which we believe our system clock to differ from
* real time. */
void
ftime_set_estimated_skew(int seconds)
{
ftime_skew = seconds;
}
#if 0
void
ftime_get_window(time_t now, ftime_t *ft_out)
{
ft_out->earliest = now + ftime_skew - ftime_slop;
ft_out->latest = now + ftime_skew + ftime_slop;
}
#endif
/** Return true iff we think that <b>now</b> might be after <b>when</b>. */
int
ftime_maybe_after(time_t now, time_t when)
{
/* It may be after when iff the latest possible current time is after when */
return (now + ftime_skew + ftime_slop) >= when;
}
/** Return true iff we think that <b>now</b> might be before <b>when</b>. */
int
ftime_maybe_before(time_t now, time_t when)
{
/* It may be before when iff the earliest possible current time is before */
return (now + ftime_skew - ftime_slop) < when;
}
/** Return true if we think that <b>now</b> is definitely after <b>when</b>. */
int
ftime_definitely_after(time_t now, time_t when)
{
/* It is definitely after when if the earliest time it could be is still
* after when. */
return (now + ftime_skew - ftime_slop) >= when;
}
/** Return true if we think that <b>now</b> is definitely before <b>when</b>.
*/
int
ftime_definitely_before(time_t now, time_t when)
{
/* It is definitely before when if the latest time it could be is still
* before when. */
return (now + ftime_skew + ftime_slop) < when;
}
/* =====
* Rate limiting
* ===== */
/** If the rate-limiter <b>lim</b> is ready at <b>now</b>, return the number
* of calls to rate_limit_is_ready (including this one!) since the last time
* rate_limit_is_ready returned nonzero. Otherwise return 0. */
static int
rate_limit_is_ready(ratelim_t *lim, time_t now)
{
if (lim->rate + lim->last_allowed <= now) {
int res = lim->n_calls_since_last_time + 1;
lim->last_allowed = now;
lim->n_calls_since_last_time = 0;
return res;
} else {
++lim->n_calls_since_last_time;
return 0;
}
}
/** If the rate-limiter <b>lim</b> is ready at <b>now</b>, return a newly
* allocated string indicating how many messages were suppressed, suitable to
* append to a log message. Otherwise return NULL. */
char *
rate_limit_log(ratelim_t *lim, time_t now)
{
int n;
if ((n = rate_limit_is_ready(lim, now))) {
if (n == 1) {
return tor_strdup("");
} else {
char *cp=NULL;
tor_asprintf(&cp,
" [%d similar message(s) suppressed in last %d seconds]",
n-1, lim->rate);
return cp;
}
} else {
return NULL;
}
}
/* =====
* File helpers
* ===== */
/** Write <b>count</b> bytes from <b>buf</b> to <b>fd</b>. <b>isSocket</b>
* must be 1 if fd was returned by socket() or accept(), and 0 if fd
* was returned by open(). Return the number of bytes written, or -1
* on error. Only use if fd is a blocking fd. */
ssize_t
write_all(int fd, const char *buf, size_t count, int isSocket)
{
size_t written = 0;
ssize_t result;
tor_assert(count < SSIZE_T_MAX);
while (written != count) {
if (isSocket)
result = tor_socket_send(fd, buf+written, count-written, 0);
else
result = write(fd, buf+written, count-written);
if (result<0)
return -1;
written += result;
}
return (ssize_t)count;
}
/** Read from <b>fd</b> to <b>buf</b>, until we get <b>count</b> bytes
* or reach the end of the file. <b>isSocket</b> must be 1 if fd
* was returned by socket() or accept(), and 0 if fd was returned by
* open(). Return the number of bytes read, or -1 on error. Only use
* if fd is a blocking fd. */
ssize_t
read_all(int fd, char *buf, size_t count, int isSocket)
{
size_t numread = 0;
ssize_t result;
if (count > SIZE_T_CEILING || count > SSIZE_T_MAX)
return -1;
while (numread != count) {
if (isSocket)
result = tor_socket_recv(fd, buf+numread, count-numread, 0);
else
result = read(fd, buf+numread, count-numread);
if (result<0)
return -1;
else if (result == 0)
break;
numread += result;
}
return (ssize_t)numread;
}
/*
* Filesystem operations.
*/
/** Clean up <b>name</b> so that we can use it in a call to "stat". On Unix,
* we do nothing. On Windows, we remove a trailing slash, unless the path is
* the root of a disk. */
static void
clean_name_for_stat(char *name)
{
#ifdef MS_WINDOWS
size_t len = strlen(name);
if (!len)
return;
if (name[len-1]=='\\' || name[len-1]=='/') {
if (len == 1 || (len==3 && name[1]==':'))
return;
name[len-1]='\0';
}
#else
(void)name;
#endif
}
/** Return FN_ERROR if filename can't be read, FN_NOENT if it doesn't
* exist, FN_FILE if it is a regular file, or FN_DIR if it's a
* directory. On FN_ERROR, sets errno. */
file_status_t
file_status(const char *fname)
{
struct stat st;
char *f;
int r;
f = tor_strdup(fname);
clean_name_for_stat(f);
r = stat(f, &st);
tor_free(f);
if (r) {
if (errno == ENOENT) {
return FN_NOENT;
}
return FN_ERROR;
}
if (st.st_mode & S_IFDIR)
return FN_DIR;
else if (st.st_mode & S_IFREG)
return FN_FILE;
else
return FN_ERROR;
}
/** Check whether dirname exists and is private. If yes return 0. If
* it does not exist, and check==CPD_CREATE is set, try to create it
* and return 0 on success. If it does not exist, and
* check==CPD_CHECK, and we think we can create it, return 0. Else
* return -1. */
int
check_private_dir(const char *dirname, cpd_check_t check)
{
int r;
struct stat st;
char *f;
tor_assert(dirname);
f = tor_strdup(dirname);
clean_name_for_stat(f);
r = stat(f, &st);
tor_free(f);
if (r) {
if (errno != ENOENT) {
log_warn(LD_FS, "Directory %s cannot be read: %s", dirname,
strerror(errno));
return -1;
}
if (check == CPD_NONE) {
log_warn(LD_FS, "Directory %s does not exist.", dirname);
return -1;
} else if (check == CPD_CREATE) {
log_info(LD_GENERAL, "Creating directory %s", dirname);
#if defined (MS_WINDOWS) && !defined (WINCE)
r = mkdir(dirname);
#else
r = mkdir(dirname, 0700);
#endif
if (r) {
log_warn(LD_FS, "Error creating directory %s: %s", dirname,
strerror(errno));
return -1;
}
}
/* XXXX In the case where check==CPD_CHECK, we should look at the
* parent directory a little harder. */
return 0;
}
if (!(st.st_mode & S_IFDIR)) {
log_warn(LD_FS, "%s is not a directory", dirname);
return -1;
}
#ifndef MS_WINDOWS
if (st.st_uid != getuid()) {
struct passwd *pw = NULL;
char *process_ownername = NULL;
pw = getpwuid(getuid());
process_ownername = pw ? tor_strdup(pw->pw_name) : tor_strdup("<unknown>");
pw = getpwuid(st.st_uid);
log_warn(LD_FS, "%s is not owned by this user (%s, %d) but by "
"%s (%d). Perhaps you are running Tor as the wrong user?",
dirname, process_ownername, (int)getuid(),
pw ? pw->pw_name : "<unknown>", (int)st.st_uid);
tor_free(process_ownername);
return -1;
}
if (st.st_mode & 0077) {
log_warn(LD_FS, "Fixing permissions on directory %s", dirname);
if (chmod(dirname, 0700)) {
log_warn(LD_FS, "Could not chmod directory %s: %s", dirname,
strerror(errno));
return -1;
} else {
return 0;
}
}
#endif
return 0;
}
/** Create a file named <b>fname</b> with the contents <b>str</b>. Overwrite
* the previous <b>fname</b> if possible. Return 0 on success, -1 on failure.
*
* This function replaces the old file atomically, if possible. This
* function, and all other functions in util.c that create files, create them
* with mode 0600.
*/
int
write_str_to_file(const char *fname, const char *str, int bin)
{
#ifdef MS_WINDOWS
if (!bin && strchr(str, '\r')) {
log_warn(LD_BUG,
"We're writing a text string that already contains a CR.");
}
#endif
return write_bytes_to_file(fname, str, strlen(str), bin);
}
/** Represents a file that we're writing to, with support for atomic commit:
* we can write into a temporary file, and either remove the file on
* failure, or replace the original file on success. */
struct open_file_t {
char *tempname; /**< Name of the temporary file. */
char *filename; /**< Name of the original file. */
unsigned rename_on_close:1; /**< Are we using the temporary file or not? */
unsigned binary:1; /**< Did we open in binary mode? */
int fd; /**< fd for the open file. */
FILE *stdio_file; /**< stdio wrapper for <b>fd</b>. */
};
/** Try to start writing to the file in <b>fname</b>, passing the flags
* <b>open_flags</b> to the open() syscall, creating the file (if needed) with
* access value <b>mode</b>. If the O_APPEND flag is set, we append to the
* original file. Otherwise, we open a new temporary file in the same
* directory, and either replace the original or remove the temporary file
* when we're done.
*
* Return the fd for the newly opened file, and store working data in
* *<b>data_out</b>. The caller should not close the fd manually:
* instead, call finish_writing_to_file() or abort_writing_to_file().
* Returns -1 on failure.
*
* NOTE: When not appending, the flags O_CREAT and O_TRUNC are treated
* as true and the flag O_EXCL is treated as false.
*
* NOTE: Ordinarily, O_APPEND means "seek to the end of the file before each
* write()". We don't do that.
*/
int
start_writing_to_file(const char *fname, int open_flags, int mode,
open_file_t **data_out)
{
size_t tempname_len = strlen(fname)+16;
open_file_t *new_file = tor_malloc_zero(sizeof(open_file_t));
const char *open_name;
int append = 0;
tor_assert(fname);
tor_assert(data_out);
#if (O_BINARY != 0 && O_TEXT != 0)
tor_assert((open_flags & (O_BINARY|O_TEXT)) != 0);
#endif
new_file->fd = -1;
tor_assert(tempname_len > strlen(fname)); /*check for overflow*/
new_file->filename = tor_strdup(fname);
if (open_flags & O_APPEND) {
open_name = fname;
new_file->rename_on_close = 0;
append = 1;
open_flags &= ~O_APPEND;
} else {
open_name = new_file->tempname = tor_malloc(tempname_len);
if (tor_snprintf(new_file->tempname, tempname_len, "%s.tmp", fname)<0) {
log_warn(LD_GENERAL, "Failed to generate filename");
goto err;
}
/* We always replace an existing temporary file if there is one. */
open_flags |= O_CREAT|O_TRUNC;
open_flags &= ~O_EXCL;
new_file->rename_on_close = 1;
}
if (open_flags & O_BINARY)
new_file->binary = 1;
new_file->fd = open(open_name, open_flags, mode);
if (new_file->fd < 0) {
log_warn(LD_FS, "Couldn't open \"%s\" (%s) for writing: %s",
open_name, fname, strerror(errno));
goto err;
}
if (append) {
if (tor_fd_seekend(new_file->fd) < 0) {
log_warn(LD_FS, "Couldn't seek to end of file \"%s\": %s", open_name,
strerror(errno));
goto err;
}
}
*data_out = new_file;
return new_file->fd;
err:
if (new_file->fd >= 0)
close(new_file->fd);
*data_out = NULL;
tor_free(new_file->filename);
tor_free(new_file->tempname);
tor_free(new_file);
return -1;
}
/** Given <b>file_data</b> from start_writing_to_file(), return a stdio FILE*
* that can be used to write to the same file. The caller should not mix
* stdio calls with non-stdio calls. */
FILE *
fdopen_file(open_file_t *file_data)
{
tor_assert(file_data);
if (file_data->stdio_file)
return file_data->stdio_file;
tor_assert(file_data->fd >= 0);
if (!(file_data->stdio_file = fdopen(file_data->fd,
file_data->binary?"ab":"a"))) {
log_warn(LD_FS, "Couldn't fdopen \"%s\" [%d]: %s", file_data->filename,
file_data->fd, strerror(errno));
}
return file_data->stdio_file;
}
/** Combines start_writing_to_file with fdopen_file(): arguments are as
* for start_writing_to_file, but */
FILE *
start_writing_to_stdio_file(const char *fname, int open_flags, int mode,
open_file_t **data_out)
{
FILE *res;
if (start_writing_to_file(fname, open_flags, mode, data_out)<0)
return NULL;
if (!(res = fdopen_file(*data_out))) {
abort_writing_to_file(*data_out);
*data_out = NULL;
}
return res;
}
/** Helper function: close and free the underlying file and memory in
* <b>file_data</b>. If we were writing into a temporary file, then delete
* that file (if abort_write is true) or replaces the target file with
* the temporary file (if abort_write is false). */
static int
finish_writing_to_file_impl(open_file_t *file_data, int abort_write)
{
int r = 0;
tor_assert(file_data && file_data->filename);
if (file_data->stdio_file) {
if (fclose(file_data->stdio_file)) {
log_warn(LD_FS, "Error closing \"%s\": %s", file_data->filename,
strerror(errno));
abort_write = r = -1;
}
} else if (file_data->fd >= 0 && close(file_data->fd) < 0) {
log_warn(LD_FS, "Error flushing \"%s\": %s", file_data->filename,
strerror(errno));
abort_write = r = -1;
}
if (file_data->rename_on_close) {
tor_assert(file_data->tempname && file_data->filename);
if (abort_write) {
unlink(file_data->tempname);
} else {
tor_assert(strcmp(file_data->filename, file_data->tempname));
if (replace_file(file_data->tempname, file_data->filename)) {
log_warn(LD_FS, "Error replacing \"%s\": %s", file_data->filename,
strerror(errno));
r = -1;
}
}
}
tor_free(file_data->filename);
tor_free(file_data->tempname);
tor_free(file_data);
return r;
}
/** Finish writing to <b>file_data</b>: close the file handle, free memory as
* needed, and if using a temporary file, replace the original file with
* the temporary file. */
int
finish_writing_to_file(open_file_t *file_data)
{
return finish_writing_to_file_impl(file_data, 0);
}
/** Finish writing to <b>file_data</b>: close the file handle, free memory as
* needed, and if using a temporary file, delete it. */
int
abort_writing_to_file(open_file_t *file_data)
{
return finish_writing_to_file_impl(file_data, 1);
}
/** Helper: given a set of flags as passed to open(2), open the file
* <b>fname</b> and write all the sized_chunk_t structs in <b>chunks</b> to
* the file. Do so as atomically as possible e.g. by opening temp files and
* renaming. */
static int
write_chunks_to_file_impl(const char *fname, const smartlist_t *chunks,
int open_flags)
{
open_file_t *file = NULL;
int fd;
ssize_t result;
fd = start_writing_to_file(fname, open_flags, 0600, &file);
if (fd<0)
return -1;
SMARTLIST_FOREACH(chunks, sized_chunk_t *, chunk,
{
result = write_all(fd, chunk->bytes, chunk->len, 0);
if (result < 0) {
log_warn(LD_FS, "Error writing to \"%s\": %s", fname,
strerror(errno));
goto err;
}
tor_assert((size_t)result == chunk->len);
});
return finish_writing_to_file(file);
err:
abort_writing_to_file(file);
return -1;
}
/** Given a smartlist of sized_chunk_t, write them atomically to a file
* <b>fname</b>, overwriting or creating the file as necessary. */
int
write_chunks_to_file(const char *fname, const smartlist_t *chunks, int bin)
{
int flags = OPEN_FLAGS_REPLACE|(bin?O_BINARY:O_TEXT);
return write_chunks_to_file_impl(fname, chunks, flags);
}
/** As write_str_to_file, but does not assume a NUL-terminated
* string. Instead, we write <b>len</b> bytes, starting at <b>str</b>. */
int
write_bytes_to_file(const char *fname, const char *str, size_t len,
int bin)
{
int flags = OPEN_FLAGS_REPLACE|(bin?O_BINARY:O_TEXT);
int r;
sized_chunk_t c = { str, len };
smartlist_t *chunks = smartlist_create();
smartlist_add(chunks, &c);
r = write_chunks_to_file_impl(fname, chunks, flags);
smartlist_free(chunks);
return r;
}
/** As write_bytes_to_file, but if the file already exists, append the bytes
* to the end of the file instead of overwriting it. */
int
append_bytes_to_file(const char *fname, const char *str, size_t len,
int bin)
{
int flags = OPEN_FLAGS_APPEND|(bin?O_BINARY:O_TEXT);
int r;
sized_chunk_t c = { str, len };
smartlist_t *chunks = smartlist_create();
smartlist_add(chunks, &c);
r = write_chunks_to_file_impl(fname, chunks, flags);
smartlist_free(chunks);
return r;
}
/** Read the contents of <b>filename</b> into a newly allocated
* string; return the string on success or NULL on failure.
*
* If <b>stat_out</b> is provided, store the result of stat()ing the
* file into <b>stat_out</b>.
*
* If <b>flags</b> & RFTS_BIN, open the file in binary mode.
* If <b>flags</b> & RFTS_IGNORE_MISSING, don't warn if the file
* doesn't exist.
*/
/*
* This function <em>may</em> return an erroneous result if the file
* is modified while it is running, but must not crash or overflow.
* Right now, the error case occurs when the file length grows between
* the call to stat and the call to read_all: the resulting string will
* be truncated.
*/
char *
read_file_to_str(const char *filename, int flags, struct stat *stat_out)
{
int fd; /* router file */
struct stat statbuf;
char *string;
ssize_t r;
int bin = flags & RFTS_BIN;
tor_assert(filename);
fd = open(filename,O_RDONLY|(bin?O_BINARY:O_TEXT),0);
if (fd<0) {
int severity = LOG_WARN;
int save_errno = errno;
if (errno == ENOENT && (flags & RFTS_IGNORE_MISSING))
severity = LOG_INFO;
log_fn(severity, LD_FS,"Could not open \"%s\": %s ",filename,
strerror(errno));
errno = save_errno;
return NULL;
}
if (fstat(fd, &statbuf)<0) {
int save_errno = errno;
close(fd);
log_warn(LD_FS,"Could not fstat \"%s\".",filename);
errno = save_errno;
return NULL;
}
if ((uint64_t)(statbuf.st_size)+1 > SIZE_T_MAX)
return NULL;
string = tor_malloc((size_t)(statbuf.st_size+1));
r = read_all(fd,string,(size_t)statbuf.st_size,0);
if (r<0) {
int save_errno = errno;
log_warn(LD_FS,"Error reading from file \"%s\": %s", filename,
strerror(errno));
tor_free(string);
close(fd);
errno = save_errno;
return NULL;
}
string[r] = '\0'; /* NUL-terminate the result. */
#ifdef MS_WINDOWS
if (!bin && strchr(string, '\r')) {
log_debug(LD_FS, "We didn't convert CRLF to LF as well as we hoped "
"when reading %s. Coping.",
filename);
tor_strstrip(string, "\r");
r = strlen(string);
}
if (!bin) {
statbuf.st_size = (size_t) r;
} else
#endif
if (r != statbuf.st_size) {
/* Unless we're using text mode on win32, we'd better have an exact
* match for size. */
int save_errno = errno;
log_warn(LD_FS,"Could read only %d of %ld bytes of file \"%s\".",
(int)r, (long)statbuf.st_size,filename);
tor_free(string);
close(fd);
errno = save_errno;
return NULL;
}
close(fd);
if (stat_out) {
memcpy(stat_out, &statbuf, sizeof(struct stat));
}
return string;
}
#define TOR_ISODIGIT(c) ('0' <= (c) && (c) <= '7')
/** Given a c-style double-quoted escaped string in <b>s</b>, extract and
* decode its contents into a newly allocated string. On success, assign this
* string to *<b>result</b>, assign its length to <b>size_out</b> (if
* provided), and return a pointer to the position in <b>s</b> immediately
* after the string. On failure, return NULL.
*/
static const char *
unescape_string(const char *s, char **result, size_t *size_out)
{
const char *cp;
char *out;
if (s[0] != '\"')
return NULL;
cp = s+1;
while (1) {
switch (*cp) {
case '\0':
case '\n':
return NULL;
case '\"':
goto end_of_loop;
case '\\':
if ((cp[1] == 'x' || cp[1] == 'X')
&& TOR_ISXDIGIT(cp[2]) && TOR_ISXDIGIT(cp[3])) {
cp += 4;
} else if (TOR_ISODIGIT(cp[1])) {
cp += 2;
if (TOR_ISODIGIT(*cp)) ++cp;
if (TOR_ISODIGIT(*cp)) ++cp;
} else if (cp[1]) {
cp += 2;
} else {
return NULL;
}
break;
default:
++cp;
break;
}
}
end_of_loop:
out = *result = tor_malloc(cp-s + 1);
cp = s+1;
while (1) {
switch (*cp)
{
case '\"':
*out = '\0';
if (size_out) *size_out = out - *result;
return cp+1;
case '\0':
tor_fragile_assert();
tor_free(*result);
return NULL;
case '\\':
switch (cp[1])
{
case 'n': *out++ = '\n'; cp += 2; break;
case 'r': *out++ = '\r'; cp += 2; break;
case 't': *out++ = '\t'; cp += 2; break;
case 'x': case 'X':
*out++ = ((hex_decode_digit(cp[2])<<4) +
hex_decode_digit(cp[3]));
cp += 4;
break;
case '0': case '1': case '2': case '3': case '4': case '5':
case '6': case '7':
{
int n = cp[1]-'0';
cp += 2;
if (TOR_ISODIGIT(*cp)) { n = n*8 + *cp-'0'; cp++; }
if (TOR_ISODIGIT(*cp)) { n = n*8 + *cp-'0'; cp++; }
if (n > 255) { tor_free(*result); return NULL; }
*out++ = (char)n;
}
break;
case '\'':
case '\"':
case '\\':
case '\?':
*out++ = cp[1];
cp += 2;
break;
default:
tor_free(*result); return NULL;
}
break;
default:
*out++ = *cp++;
}
}
}
/** Given a string containing part of a configuration file or similar format,
* advance past comments and whitespace and try to parse a single line. If we
* parse a line successfully, set *<b>key_out</b> to a new string holding the
* key portion and *<b>value_out</b> to a new string holding the value portion
* of the line, and return a pointer to the start of the next line. If we run
* out of data, return a pointer to the end of the string. If we encounter an
* error, return NULL.
*/
const char *
parse_config_line_from_str(const char *line, char **key_out, char **value_out)
{
/* I believe the file format here is supposed to be:
FILE = (EMPTYLINE | LINE)* (EMPTYLASTLINE | LASTLINE)?
EMPTYLASTLINE = SPACE* | COMMENT
EMPTYLINE = EMPTYLASTLINE NL
SPACE = ' ' | '\r' | '\t'
COMMENT = '#' NOT-NL*
NOT-NL = Any character except '\n'
NL = '\n'
LASTLINE = SPACE* KEY SPACE* VALUES
LINE = LASTLINE NL
KEY = KEYCHAR+
KEYCHAR = Any character except ' ', '\r', '\n', '\t', '#', "\"
VALUES = QUOTEDVALUE | NORMALVALUE
QUOTEDVALUE = QUOTE QVITEM* QUOTE EOLSPACE?
QUOTE = '"'
QVCHAR = KEYCHAR | ESC ('n' | 't' | 'r' | '"' | ESC |'\'' | OCTAL | HEX)
ESC = "\\"
OCTAL = ODIGIT (ODIGIT ODIGIT?)?
HEX = ('x' | 'X') HEXDIGIT HEXDIGIT
ODIGIT = '0' .. '7'
HEXDIGIT = '0'..'9' | 'a' .. 'f' | 'A' .. 'F'
EOLSPACE = SPACE* COMMENT?
NORMALVALUE = (VALCHAR | ESC ESC_IGNORE | CONTINUATION)* EOLSPACE?
VALCHAR = Any character except ESC, '#', and '\n'
ESC_IGNORE = Any character except '#' or '\n'
CONTINUATION = ESC NL ( COMMENT NL )*
*/
const char *key, *val, *cp;
int continuation = 0;
tor_assert(key_out);
tor_assert(value_out);
*key_out = *value_out = NULL;
key = val = NULL;
/* Skip until the first keyword. */
while (1) {
while (TOR_ISSPACE(*line))
++line;
if (*line == '#') {
while (*line && *line != '\n')
++line;
} else {
break;
}
}
if (!*line) { /* End of string? */
*key_out = *value_out = NULL;
return line;
}
/* Skip until the next space or \ followed by newline. */
key = line;
while (*line && !TOR_ISSPACE(*line) && *line != '#' &&
! (line[0] == '\\' && line[1] == '\n'))
++line;
*key_out = tor_strndup(key, line-key);
/* Skip until the value. */
while (*line == ' ' || *line == '\t')
++line;
val = line;
/* Find the end of the line. */
if (*line == '\"') { // XXX No continuation handling is done here
if (!(line = unescape_string(line, value_out, NULL)))
return NULL;
while (*line == ' ' || *line == '\t')
++line;
if (*line && *line != '#' && *line != '\n')
return NULL;
} else {
/* Look for the end of the line. */
while (*line && *line != '\n' && (*line != '#' || continuation)) {
if (*line == '\\' && line[1] == '\n') {
continuation = 1;
line += 2;
} else if (*line == '#') {
do {
++line;
} while (*line && *line != '\n');
if (*line == '\n')
++line;
} else {
++line;
}
}
if (*line == '\n') {
cp = line++;
} else {
cp = line;
}
/* Now back cp up to be the last nonspace character */
while (cp>val && TOR_ISSPACE(*(cp-1)))
--cp;
tor_assert(cp >= val);
/* Now copy out and decode the value. */
*value_out = tor_strndup(val, cp-val);
if (continuation) {
char *v_out, *v_in;
v_out = v_in = *value_out;
while (*v_in) {
if (*v_in == '#') {
do {
++v_in;
} while (*v_in && *v_in != '\n');
if (*v_in == '\n')
++v_in;
} else if (v_in[0] == '\\' && v_in[1] == '\n') {
v_in += 2;
} else {
*v_out++ = *v_in++;
}
}
*v_out = '\0';
}
}
if (*line == '#') {
do {
++line;
} while (*line && *line != '\n');
}
while (TOR_ISSPACE(*line)) ++line;
return line;
}
/** Expand any homedir prefix on <b>filename</b>; return a newly allocated
* string. */
char *
expand_filename(const char *filename)
{
tor_assert(filename);
#ifdef MS_WINDOWS
return tor_strdup(filename);
#else
if (*filename == '~') {
char *home, *result=NULL;
const char *rest;
if (filename[1] == '/' || filename[1] == '\0') {
home = getenv("HOME");
if (!home) {
log_warn(LD_CONFIG, "Couldn't find $HOME environment variable while "
"expanding \"%s\"; defaulting to \"\".", filename);
home = tor_strdup("");
} else {
home = tor_strdup(home);
}
rest = strlen(filename)>=2?(filename+2):"";
} else {
#ifdef HAVE_PWD_H
char *username, *slash;
slash = strchr(filename, '/');
if (slash)
username = tor_strndup(filename+1,slash-filename-1);
else
username = tor_strdup(filename+1);
if (!(home = get_user_homedir(username))) {
log_warn(LD_CONFIG,"Couldn't get homedir for \"%s\"",username);
tor_free(username);
return NULL;
}
tor_free(username);
rest = slash ? (slash+1) : "";
#else
log_warn(LD_CONFIG, "Couldn't expend homedir on system without pwd.h");
return tor_strdup(filename);
#endif
}
tor_assert(home);
/* Remove trailing slash. */
if (strlen(home)>1 && !strcmpend(home,PATH_SEPARATOR)) {
home[strlen(home)-1] = '\0';
}
tor_asprintf(&result,"%s"PATH_SEPARATOR"%s",home,rest);
tor_free(home);
return result;
} else {
return tor_strdup(filename);
}
#endif
}
#define MAX_SCANF_WIDTH 9999
/** Helper: given an ASCII-encoded decimal digit, return its numeric value.
* NOTE: requires that its input be in-bounds. */
static int
digit_to_num(char d)
{
int num = ((int)d) - (int)'0';
tor_assert(num <= 9 && num >= 0);
return num;
}
/** Helper: Read an unsigned int from *<b>bufp</b> of up to <b>width</b>
* characters. (Handle arbitrary width if <b>width</b> is less than 0.) On
* success, store the result in <b>out</b>, advance bufp to the next
* character, and return 0. On failure, return -1. */
static int
scan_unsigned(const char **bufp, unsigned *out, int width)
{
unsigned result = 0;
int scanned_so_far = 0;
if (!bufp || !*bufp || !out)
return -1;
if (width<0)
width=MAX_SCANF_WIDTH;
while (**bufp && TOR_ISDIGIT(**bufp) && scanned_so_far < width) {
int digit = digit_to_num(*(*bufp)++);
unsigned new_result = result * 10 + digit;
if (new_result > UINT32_MAX || new_result < result)
return -1; /* over/underflow. */
result = new_result;
++scanned_so_far;
}
if (!scanned_so_far) /* No actual digits scanned */
return -1;
*out = result;
return 0;
}
/** Helper: copy up to <b>width</b> non-space characters from <b>bufp</b> to
* <b>out</b>. Make sure <b>out</b> is nul-terminated. Advance <b>bufp</b>
* to the next non-space character or the EOS. */
static int
scan_string(const char **bufp, char *out, int width)
{
int scanned_so_far = 0;
if (!bufp || !out || width < 0)
return -1;
while (**bufp && ! TOR_ISSPACE(**bufp) && scanned_so_far < width) {
*out++ = *(*bufp)++;
++scanned_so_far;
}
*out = '\0';
return 0;
}
/** Locale-independent, minimal, no-surprises scanf variant, accepting only a
* restricted pattern format. For more info on what it supports, see
* tor_sscanf() documentation. */
int
tor_vsscanf(const char *buf, const char *pattern, va_list ap)
{
int n_matched = 0;
while (*pattern) {
if (*pattern != '%') {
if (*buf == *pattern) {
++buf;
++pattern;
continue;
} else {
return n_matched;
}
} else {
int width = -1;
++pattern;
if (TOR_ISDIGIT(*pattern)) {
width = digit_to_num(*pattern++);
while (TOR_ISDIGIT(*pattern)) {
width *= 10;
width += digit_to_num(*pattern++);
if (width > MAX_SCANF_WIDTH)
return -1;
}
if (!width) /* No zero-width things. */
return -1;
}
if (*pattern == 'u') {
unsigned *u = va_arg(ap, unsigned *);
if (!*buf)
return n_matched;
if (scan_unsigned(&buf, u, width)<0)
return n_matched;
++pattern;
++n_matched;
} else if (*pattern == 's') {
char *s = va_arg(ap, char *);
if (width < 0)
return -1;
if (scan_string(&buf, s, width)<0)
return n_matched;
++pattern;
++n_matched;
} else if (*pattern == 'c') {
char *ch = va_arg(ap, char *);
if (width != -1)
return -1;
if (!*buf)
return n_matched;
*ch = *buf++;
++pattern;
++n_matched;
} else if (*pattern == '%') {
if (*buf != '%')
return -1;
++buf;
++pattern;
} else {
return -1; /* Unrecognized pattern component. */
}
}
}
return n_matched;
}
/** Minimal sscanf replacement: parse <b>buf</b> according to <b>pattern</b>
* and store the results in the corresponding argument fields. Differs from
* sscanf in that it: Only handles %u and %Ns. Does not handle arbitrarily
* long widths. %u does not consume any space. Is locale-independent.
* Returns -1 on malformed patterns.
*
* (As with other locale-independent functions, we need this to parse data that
* is in ASCII without worrying that the C library's locale-handling will make
* miscellaneous characters look like numbers, spaces, and so on.)
*/
int
tor_sscanf(const char *buf, const char *pattern, ...)
{
int r;
va_list ap;
va_start(ap, pattern);
r = tor_vsscanf(buf, pattern, ap);
va_end(ap);
return r;
}
/** Return a new list containing the filenames in the directory <b>dirname</b>.
* Return NULL on error or if <b>dirname</b> is not a directory.
*/
smartlist_t *
tor_listdir(const char *dirname)
{
smartlist_t *result;
#ifdef MS_WINDOWS
char *pattern;
TCHAR tpattern[MAX_PATH] = {0};
char name[MAX_PATH] = {0};
HANDLE handle;
WIN32_FIND_DATA findData;
size_t pattern_len = strlen(dirname)+16;
pattern = tor_malloc(pattern_len);
tor_snprintf(pattern, pattern_len, "%s\\*", dirname);
#ifdef UNICODE
mbstowcs(tpattern,pattern,MAX_PATH);
#else
strlcpy(tpattern, pattern, MAX_PATH);
#endif
if (INVALID_HANDLE_VALUE == (handle = FindFirstFile(tpattern, &findData))) {
tor_free(pattern);
return NULL;
}
result = smartlist_create();
while (1) {
#ifdef UNICODE
wcstombs(name,findData.cFileName,MAX_PATH);
#else
strlcpy(name,findData.cFileName,sizeof(name));
#endif
if (strcmp(name, ".") &&
strcmp(name, "..")) {
smartlist_add(result, tor_strdup(name));
}
if (!FindNextFile(handle, &findData)) {
DWORD err;
if ((err = GetLastError()) != ERROR_NO_MORE_FILES) {
char *errstr = format_win32_error(err);
log_warn(LD_FS, "Error reading directory '%s': %s", dirname, errstr);
tor_free(errstr);
}
break;
}
}
FindClose(handle);
tor_free(pattern);
#else
DIR *d;
struct dirent *de;
if (!(d = opendir(dirname)))
return NULL;
result = smartlist_create();
while ((de = readdir(d))) {
if (!strcmp(de->d_name, ".") ||
!strcmp(de->d_name, ".."))
continue;
smartlist_add(result, tor_strdup(de->d_name));
}
closedir(d);
#endif
return result;
}
/** Return true iff <b>filename</b> is a relative path. */
int
path_is_relative(const char *filename)
{
if (filename && filename[0] == '/')
return 0;
#ifdef MS_WINDOWS
else if (filename && filename[0] == '\\')
return 0;
else if (filename && strlen(filename)>3 && TOR_ISALPHA(filename[0]) &&
filename[1] == ':' && filename[2] == '\\')
return 0;
#endif
else
return 1;
}
/* =====
* Process helpers
* ===== */
#ifndef MS_WINDOWS
/* Based on code contributed by christian grothoff */
/** True iff we've called start_daemon(). */
static int start_daemon_called = 0;
/** True iff we've called finish_daemon(). */
static int finish_daemon_called = 0;
/** Socketpair used to communicate between parent and child process while
* daemonizing. */
static int daemon_filedes[2];
/** Start putting the process into daemon mode: fork and drop all resources
* except standard fds. The parent process never returns, but stays around
* until finish_daemon is called. (Note: it's safe to call this more
* than once: calls after the first are ignored.)
*/
void
start_daemon(void)
{
pid_t pid;
if (start_daemon_called)
return;
start_daemon_called = 1;
if (pipe(daemon_filedes)) {
log_err(LD_GENERAL,"pipe failed; exiting. Error was %s", strerror(errno));
exit(1);
}
pid = fork();
if (pid < 0) {
log_err(LD_GENERAL,"fork failed. Exiting.");
exit(1);
}
if (pid) { /* Parent */
int ok;
char c;
close(daemon_filedes[1]); /* we only read */
ok = -1;
while (0 < read(daemon_filedes[0], &c, sizeof(char))) {
if (c == '.')
ok = 1;
}
fflush(stdout);
if (ok == 1)
exit(0);
else
exit(1); /* child reported error */
} else { /* Child */
close(daemon_filedes[0]); /* we only write */
pid = setsid(); /* Detach from controlling terminal */
/*
* Fork one more time, so the parent (the session group leader) can exit.
* This means that we, as a non-session group leader, can never regain a
* controlling terminal. This part is recommended by Stevens's
* _Advanced Programming in the Unix Environment_.
*/
if (fork() != 0) {
exit(0);
}
set_main_thread(); /* We are now the main thread. */
return;
}
}
/** Finish putting the process into daemon mode: drop standard fds, and tell
* the parent process to exit. (Note: it's safe to call this more than once:
* calls after the first are ignored. Calls start_daemon first if it hasn't
* been called already.)
*/
void
finish_daemon(const char *desired_cwd)
{
int nullfd;
char c = '.';
if (finish_daemon_called)
return;
if (!start_daemon_called)
start_daemon();
finish_daemon_called = 1;
if (!desired_cwd)
desired_cwd = "/";
/* Don't hold the wrong FS mounted */
if (chdir(desired_cwd) < 0) {
log_err(LD_GENERAL,"chdir to \"%s\" failed. Exiting.",desired_cwd);
exit(1);
}
nullfd = open("/dev/null", O_RDWR);
if (nullfd < 0) {
log_err(LD_GENERAL,"/dev/null can't be opened. Exiting.");
exit(1);
}
/* close fds linking to invoking terminal, but
* close usual incoming fds, but redirect them somewhere
* useful so the fds don't get reallocated elsewhere.
*/
if (dup2(nullfd,0) < 0 ||
dup2(nullfd,1) < 0 ||
dup2(nullfd,2) < 0) {
log_err(LD_GENERAL,"dup2 failed. Exiting.");
exit(1);
}
if (nullfd > 2)
close(nullfd);
/* signal success */
if (write(daemon_filedes[1], &c, sizeof(char)) != sizeof(char)) {
log_err(LD_GENERAL,"write failed. Exiting.");
}
close(daemon_filedes[1]);
}
#else
/* defined(MS_WINDOWS) */
void
start_daemon(void)
{
}
void
finish_daemon(const char *cp)
{
(void)cp;
}
#endif
/** Write the current process ID, followed by NL, into <b>filename</b>.
*/
void
write_pidfile(char *filename)
{
FILE *pidfile;
if ((pidfile = fopen(filename, "w")) == NULL) {
log_warn(LD_FS, "Unable to open \"%s\" for writing: %s", filename,
strerror(errno));
} else {
#ifdef MS_WINDOWS
fprintf(pidfile, "%d\n", (int)_getpid());
#else
fprintf(pidfile, "%d\n", (int)getpid());
#endif
fclose(pidfile);
}
}
#ifdef MS_WINDOWS
HANDLE
load_windows_system_library(const TCHAR *library_name)
{
TCHAR path[MAX_PATH];
unsigned n;
n = GetSystemDirectory(path, MAX_PATH);
if (n == 0 || n + _tcslen(library_name) + 2 >= MAX_PATH)
return 0;
_tcscat(path, TEXT("\\"));
_tcscat(path, library_name);
return LoadLibrary(path);
}
#endif