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

diff --git a/src/network/inet_pton.c b/src/network/inet_pton.c
index 8f7c17b52d60b14e2dcc7304e46b284d1d1fb307..f840dd448d8b52a9e7072feaf1099203eeec9bd6 100644 (file)
--- a/src/network/inet_pton.c
+++ b/src/network/inet_pton.c
@@ -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));