Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Tree: 618296ef57
Fetching contributors…

Cannot retrieve contributors at this time

328 lines (287 sloc) 7.979 kB
/* $Id: inet_XtoX.c,v 1.1 2006/12/04 01:55:39 mjt Exp $
* Simple implementation of the following functions:
* inet_ntop(), inet_ntoa(), inet_pton(), inet_aton().
*
* Differences from traditional implementaitons:
* o modifies destination buffers even on error return.
* o no fancy (hex, or 1.2) input support in inet_aton()
* o inet_aton() does not accept junk after an IP address.
* o inet_ntop(AF_INET) requires at least 16 bytes in dest,
* and inet_ntop(AF_INET6) at least 40 bytes
* (traditional inet_ntop() will try to fit anyway)
*
* Compile with -Dinet_XtoX_prefix=pfx_ to have pfx_*() instead of inet_*()
* Compile with -Dinet_XtoX_no_ntop or -Dinet_XtoX_no_pton
* to disable net2str or str2net conversions.
*
* #define inet_XtoX_prototypes and #include "this_file.c"
* to get function prototypes only (but not for inet_ntoa()).
* #define inet_XtoX_decl to be `static' for static visibility,
* or use __declspec(dllexport) or somesuch...
*
* Compile with -DTEST to test against stock implementation.
*
* Written by Michael Tokarev. Public domain.
*/
#ifdef inet_XtoX_prototypes
struct in_addr;
#else
#include <errno.h>
#ifdef TEST
# include <netinet/in.h>
# include <sys/socket.h>
# include <arpa/inet.h>
# include <stdio.h>
# include <stdlib.h>
# include <unistd.h>
# include <string.h>
# undef inet_XtoX_prefix
# define inet_XtoX_prefix mjt_inet_
# undef inet_XtoX_no_ntop
# undef inet_XtoX_no_pton
#else /* !TEST */
struct in_addr { /* declare it here to avoid messing with headers */
unsigned char x[4];
};
#endif /* TEST */
#endif /* inet_XtoX_prototypes */
#ifndef inet_XtoX_prefix
# define inet_XtoX_prefix inet_
#endif
#ifndef inet_XtoX_decl
# define inet_XtoX_decl /*empty*/
#endif
#define cc2_(x,y) cc2__(x,y)
#define cc2__(x,y) x##y
#define fn(x) cc2_(inet_XtoX_prefix,x)
#ifndef inet_XtoX_no_ntop
inet_XtoX_decl const char *
fn(ntop)(int af, const void *src, char *dst, unsigned size);
#ifndef inet_XtoX_prototypes
static int mjt_ntop4(const void *_src, char *dst, int size) {
unsigned i, x, r;
char *p;
const unsigned char *s = _src;
if (size < 4*4) /* for simplicity, disallow non-max-size buffer */
return 0;
for (i = 0, p = dst; i < 4; ++i) {
if (i) *p++ = '.';
x = r = s[i];
if (x > 99) { *p++ = (char)(r / 100 + '0'); r %= 100; }
if (x > 9) { *p++ = (char)(r / 10 + '0'); r %= 10; }
*p++ = (char)(r + '0');
}
*p = '\0';
return 1;
}
static char *hexc(char *p, unsigned x) {
static char hex[16] = "0123456789abcdef";
if (x > 0x0fff) *p++ = hex[(x >>12) & 15];
if (x > 0x00ff) *p++ = hex[(x >> 8) & 15];
if (x > 0x000f) *p++ = hex[(x >> 4) & 15];
*p++ = hex[x & 15];
return p;
}
static int mjt_ntop6(const void *_src, char *dst, int size) {
unsigned i;
unsigned short w[8];
unsigned bs = 0, cs = 0;
unsigned bl = 0, cl = 0;
char *p;
const unsigned char *s = _src;
if (size < 40) /* for simplicity, disallow non-max-size buffer */
return 0;
for(i = 0; i < 8; ++i, s += 2) {
w[i] = (((unsigned short)(s[0])) << 8) | s[1];
if (!w[i]) {
if (!cl++) cs = i;
}
else {
if (cl > bl) bl = cl, bs = cs;
}
}
if (cl > bl) bl = cl, bs = cs;
p = dst;
if (bl == 1)
bl = 0;
if (bl) {
for(i = 0; i < bs; ++i) {
if (i) *p++ = ':';
p = hexc(p, w[i]);
}
*p++ = ':';
i += bl;
if (i == 8)
*p++ = ':';
}
else
i = 0;
for(; i < 8; ++i) {
if (i) *p++ = ':';
if (i == 6 && !bs && (bl == 6 || (bl == 5 && w[5] == 0xffff)))
return mjt_ntop4(s - 4, p, size - (p - dst));
p = hexc(p, w[i]);
}
*p = '\0';
return 1;
}
inet_XtoX_decl const char *
fn(ntop)(int af, const void *src, char *dst, unsigned size) {
switch(af) {
/* don't use AF_*: don't mess with headers */
case 2: /* AF_INET */ if (mjt_ntop4(src, dst, size)) return dst; break;
case 10: /* AF_INET6 */ if (mjt_ntop6(src, dst, size)) return dst; break;
default: errno = EAFNOSUPPORT; return (char*)0;
}
errno = ENOSPC;
return (char*)0;
}
inet_XtoX_decl const char *
fn(ntoa)(struct in_addr addr) {
static char buf[4*4];
mjt_ntop4(&addr, buf, sizeof(buf));
return buf;
}
#endif /* inet_XtoX_prototypes */
#endif /* inet_XtoX_no_ntop */
#ifndef inet_XtoX_no_pton
inet_XtoX_decl int fn(pton)(int af, const char *src, void *dst);
inet_XtoX_decl int fn(aton)(const char *src, struct in_addr *addr);
#ifndef inet_XtoX_prototypes
static int mjt_pton4(const char *c, void *dst) {
unsigned char *a = dst;
unsigned n, o;
for (n = 0; n < 4; ++n) {
if (*c < '0' || *c > '9')
return 0;
o = *c++ - '0';
while(*c >= '0' && *c <= '9')
if ((o = o * 10 + (*c++ - '0')) > 255)
return 0;
if (*c++ != (n == 3 ? '\0' : '.'))
return 0;
*a++ = (unsigned char)o;
}
return 1;
}
static int mjt_pton6(const char *c, void *dst) {
unsigned short w[8], *a = w, *z, *i;
unsigned v, o;
const char *sc;
unsigned char *d = dst;
if (*c != ':') z = (unsigned short*)0;
else if (*++c != ':') return 0;
else ++c, z = a;
i = 0;
for(;;) {
v = 0;
sc = c;
for(;;) {
if (*c >= '0' && *c <= '9') o = *c - '0';
else if (*c >= 'a' && *c <= 'f') o = *c - 'a' + 10;
else if (*c >= 'A' && *c <= 'F') o = *c - 'A' + 10;
else break;
v = (v << 4) | o;
if (v > 0xffff) return 0;
++c;
}
if (sc == c) {
if (z == a && !*c)
break;
else
return 0;
}
if (*c == ':') {
if (a >= w + 8)
return 0;
*a++ = v;
if (*++c == ':') {
if (z)
return 0;
z = a;
if (!*++c)
break;
}
}
else if (!*c) {
if (a >= w + 8)
return 0;
*a++ = v;
break;
}
else if (*c == '.') {
if (a > w + 6)
return 0;
if (!mjt_pton4(sc, d))
return 0;
*a++ = ((unsigned)(d[0]) << 8) | d[1];
*a++ = ((unsigned)(d[2]) << 8) | d[3];
break;
}
else
return 0;
}
v = w + 8 - a;
if ((v && !z) || (!v && z))
return 0;
for(i = w; ; ++i) {
if (i == z)
while(v--) { *d++ = '\0'; *d++ = '\0'; }
if (i >= a)
break;
*d++ = (unsigned char)((*i >> 8) & 255);
*d++ = (unsigned char)(*i & 255);
}
return 1;
}
inet_XtoX_decl int fn(pton)(int af, const char *src, void *dst) {
switch(af) {
/* don't use AF_*: don't mess with headers */
case 2 /* AF_INET */: return mjt_pton4(src, dst);
case 10 /* AF_INET6 */: return mjt_pton6(src, dst);
default: errno = EAFNOSUPPORT; return -1;
}
}
inet_XtoX_decl int fn(aton)(const char *src, struct in_addr *addr) {
return mjt_pton4(src, addr);
}
#endif /* inet_XtoX_prototypes */
#endif /* inet_XtoX_no_pton */
#ifdef TEST
int main(int argc, char **argv) {
int i;
char n0[16], n1[16];
char p0[64], p1[64];
int af = AF_INET;
int pl = sizeof(p0);
int r0, r1;
const char *s0, *s1;
while((i = getopt(argc, argv, "46a:p:")) != EOF) switch(i) {
case '4': af = AF_INET; break;
case '6': af = AF_INET6; break;
case 'a': case 'p': pl = atoi(optarg); break;
default: return 1;
}
for(i = optind; i < argc; ++i) {
char *a = argv[i];
printf("%s:\n", a);
r0 = inet_pton(af, a, n0);
printf(" p2n stock: %s\n",
(r0 < 0 ? "(notsupp)" : !r0 ? "(inval)" : fn(ntop)(af,n0,p0,sizeof(p0))));
r1 = fn(pton)(af, a, n1);
printf(" p2n this : %s\n",
(r1 < 0 ? "(notsupp)" : !r1 ? "(inval)" : fn(ntop)(af,n1,p1,sizeof(p1))));
if ((r0 > 0) != (r1 > 0) ||
(r0 > 0 && r1 > 0 && memcmp(n0, n1, af == AF_INET ? 4 : 16) != 0))
printf(" DIFFER!\n");
s0 = inet_ntop(af, n1, p0, pl);
printf(" n2p stock: %s\n", s0 ? s0 : "(inval)");
s1 = fn(ntop)(af, n1, p1, pl);
printf(" n2p this : %s\n", s1 ? s1 : "(inval)");
if ((s0 != 0) != (s1 != 0) ||
(s0 && s1 && strcmp(s0, s1) != 0))
printf(" DIFFER!\n");
}
return 0;
}
#endif /* TEST */
Jump to Line
Something went wrong with that request. Please try again.