didyouexpectthat_zerotierone/node/Utils.hpp
2018-01-12 18:20:00 -08:00

387 lines
11 KiB
C++

/*
* ZeroTier One - Network Virtualization Everywhere
* Copyright (C) 2011-2016 ZeroTier, Inc. https://www.zerotier.com/
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef ZT_UTILS_HPP
#define ZT_UTILS_HPP
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <time.h>
#include <string>
#include <stdexcept>
#include <vector>
#include <map>
#include "Constants.hpp"
namespace ZeroTier {
/**
* Miscellaneous utility functions and global constants
*/
class Utils
{
public:
/**
* Perform a time-invariant binary comparison
*
* @param a First binary string
* @param b Second binary string
* @param len Length of strings
* @return True if strings are equal
*/
static inline bool secureEq(const void *a,const void *b,unsigned int len)
{
uint8_t diff = 0;
for(unsigned int i=0;i<len;++i)
diff |= ( (reinterpret_cast<const uint8_t *>(a))[i] ^ (reinterpret_cast<const uint8_t *>(b))[i] );
return (diff == 0);
}
/**
* Securely zero memory, avoiding compiler optimizations and such
*/
static void burn(void *ptr,unsigned int len);
/**
* Convert binary data to hexadecimal
*
* @param data Data to convert to hex
* @param len Length of data
* @return Hexadecimal string
*/
static std::string hex(const void *data,unsigned int len);
static inline std::string hex(const std::string &data) { return hex(data.data(),(unsigned int)data.length()); }
/**
* Convert hexadecimal to binary data
*
* This ignores all non-hex characters, just stepping over them and
* continuing. Upper and lower case are supported for letters a-f.
*
* @param hex Hexadecimal ASCII code (non-hex chars are ignored, stops at zero or maxlen)
* @param maxlen Maximum length of hex string buffer
* @return Binary data
*/
static std::string unhex(const char *hex,unsigned int maxlen);
static inline std::string unhex(const std::string &hex) { return unhex(hex.c_str(),(unsigned int)hex.length()); }
/**
* Convert hexadecimal to binary data
*
* This ignores all non-hex characters, just stepping over them and
* continuing. Upper and lower case are supported for letters a-f.
*
* @param hex Hexadecimal ASCII
* @param maxlen Maximum length of hex string buffer
* @param buf Buffer to fill
* @param len Length of buffer
* @return Number of characters actually written
*/
static unsigned int unhex(const char *hex,unsigned int maxlen,void *buf,unsigned int len);
static inline unsigned int unhex(const std::string &hex,void *buf,unsigned int len) { return unhex(hex.c_str(),(unsigned int)hex.length(),buf,len); }
/**
* Generate secure random bytes
*
* This will try to use whatever OS sources of entropy are available. It's
* guarded by an internal mutex so it's thread-safe.
*
* @param buf Buffer to fill
* @param bytes Number of random bytes to generate
*/
static void getSecureRandom(void *buf,unsigned int bytes);
/**
* Tokenize a string (alias for strtok_r or strtok_s depending on platform)
*
* @param str String to split
* @param delim Delimiters
* @param saveptr Pointer to a char * for temporary reentrant storage
*/
static inline char *stok(char *str,const char *delim,char **saveptr)
throw()
{
#ifdef __WINDOWS__
return strtok_s(str,delim,saveptr);
#else
return strtok_r(str,delim,saveptr);
#endif
}
// String to number converters -- defined here to permit portability
// ifdefs for platforms that lack some of the strtoXX functions.
static inline unsigned int strToUInt(const char *s)
throw()
{
return (unsigned int)strtoul(s,(char **)0,10);
}
static inline int strToInt(const char *s)
throw()
{
return (int)strtol(s,(char **)0,10);
}
static inline unsigned long strToULong(const char *s)
throw()
{
return strtoul(s,(char **)0,10);
}
static inline long strToLong(const char *s)
throw()
{
return strtol(s,(char **)0,10);
}
static inline unsigned long long strToU64(const char *s)
throw()
{
#ifdef __WINDOWS__
return (unsigned long long)_strtoui64(s,(char **)0,10);
#else
return strtoull(s,(char **)0,10);
#endif
}
static inline long long strTo64(const char *s)
throw()
{
#ifdef __WINDOWS__
return (long long)_strtoi64(s,(char **)0,10);
#else
return strtoll(s,(char **)0,10);
#endif
}
static inline unsigned int hexStrToUInt(const char *s)
throw()
{
return (unsigned int)strtoul(s,(char **)0,16);
}
static inline int hexStrToInt(const char *s)
throw()
{
return (int)strtol(s,(char **)0,16);
}
static inline unsigned long hexStrToULong(const char *s)
throw()
{
return strtoul(s,(char **)0,16);
}
static inline long hexStrToLong(const char *s)
throw()
{
return strtol(s,(char **)0,16);
}
static inline unsigned long long hexStrToU64(const char *s)
throw()
{
#ifdef __WINDOWS__
return (unsigned long long)_strtoui64(s,(char **)0,16);
#else
return strtoull(s,(char **)0,16);
#endif
}
static inline long long hexStrTo64(const char *s)
throw()
{
#ifdef __WINDOWS__
return (long long)_strtoi64(s,(char **)0,16);
#else
return strtoll(s,(char **)0,16);
#endif
}
static inline double strToDouble(const char *s)
throw()
{
return strtod(s,(char **)0);
}
/**
* Perform a safe C string copy, ALWAYS null-terminating the result
*
* This will never ever EVER result in dest[] not being null-terminated
* regardless of any input parameter (other than len==0 which is invalid).
*
* @param dest Destination buffer (must not be NULL)
* @param len Length of dest[] (if zero, false is returned and nothing happens)
* @param src Source string (if NULL, dest will receive a zero-length string and true is returned)
* @return True on success, false on overflow (buffer will still be 0-terminated)
*/
static bool scopy(char *dest,unsigned int len,const char *src);
/**
* Variant of snprintf that is portable and throws an exception
*
* This just wraps the local implementation whatever it's called, while
* performing a few other checks and adding exceptions for overflow.
*
* @param buf Buffer to write to
* @param len Length of buffer in bytes
* @param fmt Format string
* @param ... Format arguments
* @throws std::length_error buf[] too short (buf[] will still be left null-terminated)
*/
static unsigned int snprintf(char *buf,unsigned int len,const char *fmt,...)
throw(std::length_error);
/**
* Count the number of bits set in an integer
*
* @param v 32-bit integer
* @return Number of bits set in this integer (0-32)
*/
static inline uint32_t countBits(uint32_t v)
{
v = v - ((v >> 1) & (uint32_t)0x55555555);
v = (v & (uint32_t)0x33333333) + ((v >> 2) & (uint32_t)0x33333333);
return ((((v + (v >> 4)) & (uint32_t)0xF0F0F0F) * (uint32_t)0x1010101) >> 24);
}
/**
* Count the number of bits set in an integer
*
* @param v 64-bit integer
* @return Number of bits set in this integer (0-64)
*/
static inline uint64_t countBits(uint64_t v)
{
v = v - ((v >> 1) & (uint64_t)~(uint64_t)0/3);
v = (v & (uint64_t)~(uint64_t)0/15*3) + ((v >> 2) & (uint64_t)~(uint64_t)0/15*3);
v = (v + (v >> 4)) & (uint64_t)~(uint64_t)0/255*15;
return (uint64_t)(v * ((uint64_t)~(uint64_t)0/255)) >> 56;
}
/**
* Check if a memory buffer is all-zero
*
* @param p Memory to scan
* @param len Length of memory
* @return True if memory is all zero
*/
static inline bool isZero(const void *p,unsigned int len)
{
for(unsigned int i=0;i<len;++i) {
if (((const unsigned char *)p)[i])
return false;
}
return true;
}
// Byte swappers for big/little endian conversion
static inline uint8_t hton(uint8_t n) throw() { return n; }
static inline int8_t hton(int8_t n) throw() { return n; }
static inline uint16_t hton(uint16_t n) throw() { return htons(n); }
static inline int16_t hton(int16_t n) throw() { return (int16_t)htons((uint16_t)n); }
static inline uint32_t hton(uint32_t n) throw() { return htonl(n); }
static inline int32_t hton(int32_t n) throw() { return (int32_t)htonl((uint32_t)n); }
static inline uint64_t hton(uint64_t n)
throw()
{
#if __BYTE_ORDER == __LITTLE_ENDIAN
#if defined(__GNUC__) && (!defined(__OpenBSD__))
return __builtin_bswap64(n);
#else
return (
((n & 0x00000000000000FFULL) << 56) |
((n & 0x000000000000FF00ULL) << 40) |
((n & 0x0000000000FF0000ULL) << 24) |
((n & 0x00000000FF000000ULL) << 8) |
((n & 0x000000FF00000000ULL) >> 8) |
((n & 0x0000FF0000000000ULL) >> 24) |
((n & 0x00FF000000000000ULL) >> 40) |
((n & 0xFF00000000000000ULL) >> 56)
);
#endif
#else
return n;
#endif
}
static inline int64_t hton(int64_t n) throw() { return (int64_t)hton((uint64_t)n); }
static inline uint8_t ntoh(uint8_t n) throw() { return n; }
static inline int8_t ntoh(int8_t n) throw() { return n; }
static inline uint16_t ntoh(uint16_t n) throw() { return ntohs(n); }
static inline int16_t ntoh(int16_t n) throw() { return (int16_t)ntohs((uint16_t)n); }
static inline uint32_t ntoh(uint32_t n) throw() { return ntohl(n); }
static inline int32_t ntoh(int32_t n) throw() { return (int32_t)ntohl((uint32_t)n); }
static inline uint64_t ntoh(uint64_t n)
throw()
{
#if __BYTE_ORDER == __LITTLE_ENDIAN
#if defined(__GNUC__) && !defined(__OpenBSD__)
return __builtin_bswap64(n);
#else
return (
((n & 0x00000000000000FFULL) << 56) |
((n & 0x000000000000FF00ULL) << 40) |
((n & 0x0000000000FF0000ULL) << 24) |
((n & 0x00000000FF000000ULL) << 8) |
((n & 0x000000FF00000000ULL) >> 8) |
((n & 0x0000FF0000000000ULL) >> 24) |
((n & 0x00FF000000000000ULL) >> 40) |
((n & 0xFF00000000000000ULL) >> 56)
);
#endif
#else
return n;
#endif
}
static inline int64_t ntoh(int64_t n) throw() { return (int64_t)ntoh((uint64_t)n); }
/**
* Compare Peer version tuples
*
* @return -1, 0, or 1 based on whether first tuple is less than, equal to, or greater than second
*/
static inline int compareVersion(unsigned int maj1,unsigned int min1,unsigned int rev1,unsigned int b1,unsigned int maj2,unsigned int min2,unsigned int rev2,unsigned int b2)
{
if (maj1 > maj2)
return 1;
else if (maj1 < maj2)
return -1;
else {
if (min1 > min2)
return 1;
else if (min1 < min2)
return -1;
else {
if (rev1 > rev2)
return 1;
else if (rev1 < rev2)
return -1;
else {
if (b1 > b2)
return 1;
else if (b1 < b2)
return -1;
else return 0;
}
}
}
}
/**
* Hexadecimal characters 0-f
*/
static const char HEXCHARS[16];
};
} // namespace ZeroTier
#endif