fix inet_pton

* parse IPv4 dotted-decimal correctly (without strtoul, no leading zeros)
* disallow single leading ':' in IPv6 address
* allow at most 4 hex digits in IPv6 address (according to RFC 2373)
* have enough hex fields in IPv4 mapped IPv6 address
* disallow leading zeros in IPv4 mapped IPv6 address
This commit is contained in:
Szabolcs Nagy 2013-10-23 01:49:14 +00:00
parent 51c4e451db
commit 78f8891531

View File

@ -1,7 +1,6 @@
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
@ -18,52 +17,46 @@ int inet_pton(int af, const char *restrict s, void *restrict a0)
{
uint16_t ip[8];
unsigned char *a = a0;
const char *z;
unsigned long x;
int i, j, v, d, brk=-1, need_v4=0;
/* Reimplement this because inet_pton cannot accept special v4 forms */
if (af==AF_INET) {
for (i=0; i<4 && *s; i++) {
a[i] = x = strtoul(s, (char **)&z, 10);
if (!isdigit(*s) || z==s || (*z && *z != '.') || x>255)
return 0;
s=z+1;
for (i=0; i<4; i++) {
for (v=j=0; j<3 && isdigit(s[j]); j++)
v = 10*v + s[j]-'0';
if (j==0 || (j>1 && s[0]=='0') || v>255) return 0;
a[i] = v;
if (s[j]==0 && i==3) return 1;
if (s[j]!='.') return 0;
s += j+1;
}
return 1;
return 0;
} else if (af!=AF_INET6) {
errno = EAFNOSUPPORT;
return -1;
}
if (s[0]==':' && s[1]==':') s++;
if (*s==':' && *++s!=':') return 0;
for (i=0; ; i++, s+=j+1) {
for (i=0; ; i++) {
if (s[0]==':' && brk<0) {
brk=i;
j=0;
ip[i]=0;
if (!s[1]) break;
if (!*++s) break;
continue;
}
if (hexval(s[0])<0) return 0;
while (s[0]=='0' && s[1]=='0') s++;
for (v=j=0; j<5 && (d=hexval(s[j]))>=0; j++)
for (v=j=0; j<4 && (d=hexval(s[j]))>=0; j++)
v=16*v+d;
if (v > 65535) return 0;
if (j==0 || v > 65535) return 0;
ip[i] = v;
if (!s[j]) {
if (brk<0 && i!=7) return 0;
break;
}
if (i<7) {
if (s[j]==':') continue;
if (s[j]!='.') return 0;
if (!s[j] && (brk>=0 || i==7)) break;
if (i==7) return 0;
if (s[j]!=':') {
if (s[j]!='.' || (i<6 && brk<0)) return 0;
need_v4=1;
i++;
break;
}
return 0;
s += j+1;
}
if (brk>=0) {
memmove(ip+brk+7-i, ip+brk, 2*(i+1-brk));