windows下inet_pton和inet_ntop
code is copied from webrtc project, for possible reference.
netutils.h
#ifndef GOBJECT_EXAMPLE_NETUTILS_H_
#define GOBJECT_EXAMPLE_NETUTILS_H_
#define WIN32
#if defined (WIN32)
#include
#include
#ifndef INET6_ADDRSTRLEN
#define INET6_ADDRSTRLEN 46
#endif
#else
#include
#include
#endif
#ifdef __cplusplus
extern "C"
{
#endif
const char *rtc_inet_ntop(int af, const void *src, char* dst, socklen_t size);
int rtc_inet_pton(int af, const char* src, void *dst);
#ifdef __cplusplus
}
#endif
#endif /* GOBJECT_EXAMPLE_NETUTILS_H_ */
netutils.cc
#include "netutils.h"
#include
#include
#include
template char (&ArraySizeHelper(T (&array)[N]))[N];
#define arraysize(array) (sizeof(ArraySizeHelper(array)))
template
const CTYPE* rtc_strchr(const CTYPE* str, const CTYPE* chs) {
for (size_t i=0; str[i]; ++i) {
for (size_t j=0; chs[j]; ++j) {
if (str[i] == chs[j]) {
return str + i;
}
}
}
return 0;
}
#if defined (WIN32)
int inet_pton_v4(const char* src, void* dst) {
const int kIpv4AddressSize = 4;
int found = 0;
const char* src_pos = src;
unsigned char result[kIpv4AddressSize] = {0};
while (*src_pos != '\0') {
// strtol won't treat whitespace characters in the begining as an error,
// so check to ensure this is started with digit before passing to strtol.
if (!isdigit(*src_pos)) {
return 0;
}
char* end_pos;
long value = strtol(src_pos, &end_pos, 10);
if (value < 0 || value > 255 || src_pos == end_pos) {
return 0;
}
++found;
if (found > kIpv4AddressSize) {
return 0;
}
result[found - 1] = static_cast(value);
src_pos = end_pos;
if (*src_pos == '.') {
// There's more.
++src_pos;
} else if (*src_pos != '\0') {
// If it's neither '.' nor '\0' then return fail.
return 0;
}
}
if (found != kIpv4AddressSize) {
return 0;
}
memcpy(dst, result, sizeof(result));
return 1;
}
const char* inet_ntop_v4(const void* src, char* dst, socklen_t size) {
if (size < INET_ADDRSTRLEN) {
return nullptr;
}
const struct in_addr* as_in_addr =
reinterpret_cast(src);
snprintf(dst, size, "%d.%d.%d.%d",
as_in_addr->S_un.S_un_b.s_b1,
as_in_addr->S_un.S_un_b.s_b2,
as_in_addr->S_un.S_un_b.s_b3,
as_in_addr->S_un.S_un_b.s_b4);
return dst;
}
// Helper function for inet_ntop for IPv6 addresses.
const char* inet_ntop_v6(const void* src, char* dst, socklen_t size) {
if (size < INET6_ADDRSTRLEN) {
return nullptr;
}
const uint16_t* as_shorts = reinterpret_cast(src);
int runpos[8];
int current = 1;
int max = 0;
int maxpos = -1;
int run_array_size = arraysize(runpos);
// Run over the address marking runs of 0s.
for (int i = 0; i < run_array_size; ++i) {
if (as_shorts[i] == 0) {
runpos[i] = current;
if (current > max) {
maxpos = i;
max = current;
}
++current;
} else {
runpos[i] = -1;
current = 1;
}
}
if (max > 0) {
int tmpmax = maxpos;
// Run back through, setting -1 for all but the longest run.
for (int i = run_array_size - 1; i >= 0; i--) {
if (i > tmpmax) {
runpos[i] = -1;
} else if (runpos[i] == -1) {
// We're less than maxpos, we hit a -1, so the 'good' run is done.
// Setting tmpmax -1 means all remaining positions get set to -1.
tmpmax = -1;
}
}
}
char* cursor = dst;
// Print IPv4 compatible and IPv4 mapped addresses using the IPv4 helper.
// These addresses have an initial run of either eight zero-bytes followed
// by 0xFFFF, or an initial run of ten zero-bytes.
if (runpos[0] == 1 && (maxpos == 5 ||
(maxpos == 4 && as_shorts[5] == 0xFFFF))) {
*cursor++ = ':';
*cursor++ = ':';
if (maxpos == 4) {
cursor += snprintf(cursor, INET6_ADDRSTRLEN - 2, "ffff:");
}
const struct in_addr* as_v4 =
reinterpret_cast(&(as_shorts[6]));
inet_ntop_v4(as_v4, cursor,
static_cast(INET6_ADDRSTRLEN - (cursor - dst)));
} else {
for (int i = 0; i < run_array_size; ++i) {
if (runpos[i] == -1) {
cursor += snprintf(cursor,
INET6_ADDRSTRLEN - (cursor - dst),
"%x", ntohs(as_shorts[i]));
if (i != 7 && runpos[i + 1] != 1) {
*cursor++ = ':';
}
} else if (runpos[i] == 1) {
// Entered the run; print the colons and skip the run.
*cursor++ = ':';
*cursor++ = ':';
i += (max - 1);
}
}
}
return dst;
}
int inet_pton_v6(const char* src, void* dst) {
// sscanf will pick any other invalid chars up, but it parses 0xnnnn as hex.
// Check for literal x in the input string.
const char* readcursor = src;
char c = *readcursor++;
while (c) {
if (c == 'x') {
return 0;
}
c = *readcursor++;
}
readcursor = src;
struct in6_addr an_addr;
memset(&an_addr, 0, sizeof(an_addr));
uint16_t* addr_cursor = reinterpret_cast(&an_addr.s6_addr[0]);
uint16_t* addr_end = reinterpret_cast(&an_addr.s6_addr[16]);
bool seencompressed = false;
// Addresses that start with "::" (i.e., a run of initial zeros) or
// "::ffff:" can potentially be IPv4 mapped or compatibility addresses.
// These have dotted-style IPv4 addresses on the end (e.g. "::192.168.7.1").
if (*readcursor == ':' && *(readcursor+1) == ':' &&
*(readcursor + 2) != 0) {
// Check for periods, which we'll take as a sign of v4 addresses.
const char* addrstart = readcursor + 2;
if (rtc_strchr(addrstart, ".")) {
const char* colon = rtc_strchr(addrstart, "::");
if (colon) {
uint16_t a_short;
int bytesread = 0;
if (sscanf(addrstart, "%hx%n", &a_short, &bytesread) != 1 ||
a_short != 0xFFFF || bytesread != 4) {
// Colons + periods means has to be ::ffff:a.b.c.d. But it wasn't.
return 0;
} else {
an_addr.s6_addr[10] = 0xFF;
an_addr.s6_addr[11] = 0xFF;
addrstart = colon + 1;
}
}
struct in_addr v4;
if (inet_pton_v4(addrstart, &v4.s_addr)) {
memcpy(&an_addr.s6_addr[12], &v4, sizeof(v4));
memcpy(dst, &an_addr, sizeof(an_addr));
return 1;
} else {
// Invalid v4 address.
return 0;
}
}
}
// For addresses without a trailing IPv4 component ('normal' IPv6 addresses).
while (*readcursor != 0 && addr_cursor < addr_end) {
if (*readcursor == ':') {
if (*(readcursor + 1) == ':') {
if (seencompressed) {
// Can only have one compressed run of zeroes ("::") per address.
return 0;
}
// Hit a compressed run. Count colons to figure out how much of the
// address is skipped.
readcursor += 2;
const char* coloncounter = readcursor;
int coloncount = 0;
if (*coloncounter == 0) {
// Special case - trailing ::.
addr_cursor = addr_end;
} else {
while (*coloncounter) {
if (*coloncounter == ':') {
++coloncount;
}
++coloncounter;
}
// (coloncount + 1) is the number of shorts left in the address.
// If this number is greater than the number of available shorts, the
// address is malformed.
if (coloncount + 1 > addr_end - addr_cursor) {
return 0;
}
addr_cursor = addr_end - (coloncount + 1);
seencompressed = true;
}
} else {
++readcursor;
}
} else {
uint16_t word;
int bytesread = 0;
if (sscanf(readcursor, "%4hx%n", &word, &bytesread) != 1) {
return 0;
} else {
*addr_cursor = htons(word);
++addr_cursor;
readcursor += bytesread;
if (*readcursor != ':' && *readcursor != '\0') {
return 0;
}
}
}
}
if (*readcursor != '\0' || addr_cursor < addr_end) {
// Catches addresses too short or too long.
return 0;
}
memcpy(dst, &an_addr, sizeof(an_addr));
return 1;
}
// Implementation of inet_ntop (create a printable representation of an
// ip address). XP doesn't have its own inet_ntop, and
// WSAAddressToString requires both IPv6 to be installed and for Winsock
// to be initialized.
const char* win32_inet_ntop(int af, const void *src,
char* dst, socklen_t size) {
if (!src || !dst) {
return nullptr;
}
switch (af) {
case AF_INET: {
return inet_ntop_v4(src, dst, size);
}
case AF_INET6: {
return inet_ntop_v6(src, dst, size);
}
}
return nullptr;
}
// As above, but for inet_pton. Implements inet_pton for v4 and v6.
// Note that our inet_ntop will output normal 'dotted' v4 addresses only.
int win32_inet_pton(int af, const char* src, void* dst) {
if (!src || !dst) {
return 0;
}
if (af == AF_INET) {
return inet_pton_v4(src, dst);
} else if (af == AF_INET6) {
return inet_pton_v6(src, dst);
}
return -1;
}
#endif
const char *rtc_inet_ntop(int af, const void *src, char* dst, socklen_t size){
#if defined (WIN32)
return win32_inet_ntop(af, src, dst, size);
#else
return ::inet_ntop(af, src, dst, size);
#endif
}
int rtc_inet_pton(int af, const char* src, void *dst){
#if defined (WIN32)
return win32_inet_pton(af, src, dst);
#else
return ::inet_pton(af, src, dst);
#endif
}
test1.cc
#include
#include
#include
#include "netutils.h"
int main(){
struct in_addr in4;
printf("%d\n",sizeof(in4));
char *ip="127.0.0.1";
rtc_inet_pton(AF_INET,ip,&in4);
printf("%d\n",in4);
char buf[INET6_ADDRSTRLEN];
rtc_inet_ntop(AF_INET,(void*)&in4,buf,INET6_ADDRSTRLEN);
printf("%s\n",buf);
char* ipv6 = "2001:db8:1020:3040:5060:7080:90a0:b0c0";
struct in6_addr in6;
char buf6[INET6_ADDRSTRLEN];
rtc_inet_pton(AF_INET6,ipv6,&in6);
rtc_inet_ntop(AF_INET6,(void*)&in6,buf6,INET6_ADDRSTRLEN);
printf("%s\n",buf6);
return 0;
}
test2.cc
#include
#include
#include
#include "netutils.h"
int sockaddr_init(struct sockaddr_storage* addr,int familiy,
char*ip,uint16_t port){
memset(addr,0,sizeof(*addr));
if(familiy==AF_INET){
struct sockaddr_in *_addr = (struct sockaddr_in*)addr;
_addr->sin_family = AF_INET;
if(rtc_inet_pton(AF_INET,ip,&_addr->sin_addr)!=1){
return -1;
}
_addr->sin_port=htons(port);
}
if(familiy==AF_INET6){
struct sockaddr_in6 *_addr = (struct sockaddr_in6*)addr;
_addr->sin6_family = AF_INET6;
if(rtc_inet_pton(AF_INET6,ip,&_addr->sin6_addr)!=1){
return -1;
}
_addr->sin6_port=htons(port);
}
return 0;
}
int main(){
struct sockaddr_storage serv_addr;
char *ip="127.0.0.1";
struct in_addr in4;
uint16_t port=1234;
rtc_inet_pton(AF_INET,ip,&in4);
char buf[INET6_ADDRSTRLEN];
rtc_inet_ntop(AF_INET,(void*)&in4,buf,INET6_ADDRSTRLEN);
printf("%s\n",buf);
printf("%d\n",in4);
sockaddr_init(&serv_addr,AF_INET,ip,port);
struct sockaddr_in *addr =
(struct sockaddr_in*)&serv_addr;
memset(buf,0,INET6_ADDRSTRLEN);
rtc_inet_ntop(AF_INET,&addr->sin_addr,buf,INET6_ADDRSTRLEN);
printf("%d\n",addr->sin_addr);
printf("%s\n",buf);
memset(buf,0,INET6_ADDRSTRLEN);
char* ip6 = "2001:db8:1020:3040:5060:7080:90a0:b0c0";
sockaddr_init(&serv_addr,AF_INET6,ip6,port);
struct sockaddr_in6 *addr6 =
(struct sockaddr_in6*)&serv_addr;
rtc_inet_ntop(AF_INET6,&addr6->sin6_addr,buf,INET6_ADDRSTRLEN);
printf("%s\n",buf);
return 0;
}