+ if (*s==':' && *++s!=':') return 0;
+
+ for (i=0; ; i++) {
+ if (s[0]==':' && brk<0) {
+ brk=i;
+ ip[i&7]=0;
+ if (!*++s) break;
+ if (i==7) return 0;
+ continue;
+ }
+ for (v=j=0; j<4 && (d=hexval(s[j]))>=0; j++)
+ v=16*v+d;
+ if (j==0) return 0;
+ ip[i&7] = v;
+ 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;
+ }
+ s += j+1;
+ }
+ if (brk>=0) {
+ memmove(ip+brk+7-i, ip+brk, 2*(i+1-brk));
+ for (j=0; j<7-i; j++) ip[brk+j] = 0;
+ }
+ for (j=0; j<8; j++) {
+ *a++ = ip[j]>>8;
+ *a++ = ip[j];
+ }
+ if (need_v4 && inet_pton(AF_INET, (void *)s, a-4) <= 0) return 0;
+ return 1;