maskptr NULL if no mask is permitted to follow
otherwise, points to an int where the offset of '/' is placed
if there is no / followed by trailing digits, *maskptr is set 0
+ errp NULL if no diagnostic information is required, and if the netmask
+ length should not be checked. Otherwise it is set pointing to a short
+ descriptive text.
Returns: 0 if the string is not a textual representation of an IP address
4 if it is an IPv4 address
6 if it is an IPv6 address
-*/
+The legacy string_is_ip_address() function follows below.
+*/
int
-string_is_ip_address(const uschar *s, int *maskptr)
-{
-int yield = 4;
+string_is_ip_addressX(const uschar *ip_addr, int *maskptr, const uschar **errp) {
+ struct addrinfo hints;
+ struct addrinfo *res;
-/* If an optional mask is permitted, check for it. If found, pass back the
-offset. */
+ uschar *slash, *percent;
-if (maskptr)
+ uschar *endp = 0;
+ long int mask = 0;
+ const uschar *addr = 0;
+
+ /* If there is a slash, but we didn't request a (optional) netmask,
+ we return failure, as we do if the mask isn't a pure numerical value,
+ or if it is negative. The actual length is checked later, once we know
+ the address family. */
+ if (slash = Ustrchr(ip_addr, '/'))
{
- const uschar *ss = s + Ustrlen(s);
- *maskptr = 0;
- if (s != ss && isdigit(*(--ss)))
+ if (!maskptr)
{
- while (ss > s && isdigit(ss[-1])) ss--;
- if (ss > s && *(--ss) == '/') *maskptr = ss - s;
+ if (errp) *errp = "netmask found, but not requested";
+ return 0;
}
- }
-
-/* A colon anywhere in the string => IPv6 address */
-
-if (Ustrchr(s, ':') != NULL)
- {
- BOOL had_double_colon = FALSE;
- BOOL v4end = FALSE;
-
- yield = 6;
-
- /* An IPv6 address must start with hex digit or double colon. A single
- colon is invalid. */
-
- if (*s == ':' && *(++s) != ':') return 0;
-
- /* Now read up to 8 components consisting of up to 4 hex digits each. There
- may be one and only one appearance of double colon, which implies any number
- of binary zero bits. The number of preceding components is held in count. */
- for (int count = 0; count < 8; count++)
+ uschar *rest;
+ mask = Ustrtol(slash+1, &rest, 10);
+ if (*rest || mask < 0)
{
- /* If the end of the string is reached before reading 8 components, the
- address is valid provided a double colon has been read. This also applies
- if we hit the / that introduces a mask or the % that introduces the
- interface specifier (scope id) of a link-local address. */
-
- if (*s == 0 || *s == '%' || *s == '/') return had_double_colon ? yield : 0;
-
- /* If a component starts with an additional colon, we have hit a double
- colon. This is permitted to appear once only, and counts as at least
- one component. The final component may be of this form. */
-
- if (*s == ':')
- {
- if (had_double_colon) return 0;
- had_double_colon = TRUE;
- s++;
- continue;
- }
-
- /* If the remainder of the string contains a dot but no colons, we
- can expect a trailing IPv4 address. This is valid if either there has
- been no double-colon and this is the 7th component (with the IPv4 address
- being the 7th & 8th components), OR if there has been a double-colon
- and fewer than 6 components. */
-
- if (Ustrchr(s, ':') == NULL && Ustrchr(s, '.') != NULL)
- {
- if ((!had_double_colon && count != 6) ||
- (had_double_colon && count > 6)) return 0;
- v4end = TRUE;
- yield = 6;
- break;
- }
-
- /* Check for at least one and not more than 4 hex digits for this
- component. */
-
- if (!isxdigit(*s++)) return 0;
- if (isxdigit(*s) && isxdigit(*(++s)) && isxdigit(*(++s))) s++;
-
- /* If the component is terminated by colon and there is more to
- follow, skip over the colon. If there is no more to follow the address is
- invalid. */
-
- if (*s == ':' && *(++s) == 0) return 0;
+ if (errp) *errp = "netmask not numeric or <0";
+ return 0;
}
- /* If about to handle a trailing IPv4 address, drop through. Otherwise
- all is well if we are at the end of the string or at the mask or at a percent
- sign, which introduces the interface specifier (scope id) of a link local
- address. */
+ *maskptr = slash - ip_addr; /* offset of the slash */
+ endp = slash;
+ } else if (maskptr) *maskptr = 0; /* no slash found */
- if (!v4end)
- return (*s == 0 || *s == '%' ||
- (*s == '/' && maskptr != NULL && *maskptr != 0))? yield : 0;
+ /* The interface-ID suffix (%<id>) is optional (for IPv6). If it
+ exists, we check it syntactically. Later, if we know the address
+ family is IPv4, we might reject it.
+ The interface-ID is mutually exclusive with the netmask, to the
+ best of my knowledge. */
+ if (percent = Ustrchr(ip_addr, '%'))
+ {
+ if (slash)
+ {
+ if (errp) *errp = "interface-ID and netmask are mutually exclusive";
+ return 0;
+ }
+ for (uschar *p = percent+1; *p; p++)
+ if (!isalnum(*p) && !ispunct(*p))
+ {
+ if (errp) *errp = "interface-ID must match [[:alnum:][:punct:]]";
+ return 0;
+ }
+ endp = percent;
}
-/* Test for IPv4 address, which may be the tail-end of an IPv6 address. */
-
-for (int i = 0; i < 4; i++)
+ /* inet_pton() can't parse netmasks and interface IDs, so work on a shortened copy
+ allocated on the current stack */
+ if (endp) {
+ ptrdiff_t l = endp - ip_addr;
+ if (l > 255)
+ {
+ if (errp) *errp = "rudiculous long ip address string";
+ return 0;
+ }
+ addr = alloca(l+1); /* *BSD does not have strndupa() */
+ Ustrncpy((uschar *)addr, ip_addr, l);
+ ((uschar*)addr)[l] = '\0';
+ } else addr = ip_addr;
+
+ int af;
+ union { /* we do not need this, but inet_pton() needs a place for storage */
+ struct in_addr sa4;
+ struct in6_addr sa6;
+ } sa;
+
+ af = Ustrchr(addr, ':') ? AF_INET6 : AF_INET;
+ if (!inet_pton(af, addr, &sa))
{
- long n;
- uschar * end;
-
- if (i != 0 && *s++ != '.') return 0;
- n = strtol(CCS s, CSS &end, 10);
- if (n > 255 || n < 0 || end <= s || end > s+3) return 0;
- s = end;
+ if (errp) *errp = af == AF_INET6 ? "IP address string not parsable as IPv6"
+ : "IP address string not parsable IPv4";
+ return 0;
}
+ /* we do not check the values of the mask here, as
+ this is done on the callers side (but I don't understand why), so
+ actually I'd like to do it here, but it breaks at least 0002 */
+ switch (af)
+ {
+ case AF_INET6:
+ if (errp && mask > 128)
+ {
+ *errp = "IPv6 netmask value must not be >128";
+ return 0;
+ }
+ return 6;
+ case AF_INET:
+ if (percent)
+ {
+ if (errp) *errp = "IPv4 address string must not have an interface-ID";
+ return 0;
+ }
+ if (errp && mask > 32) {
+ *errp = "IPv4 netmask value must not be >32";
+ return 0;
+ }
+ return 4;
+ default:
+ if (errp) *errp = "unknown address family (should not happen)";
+ return 0;
+ }
+}
-return !*s || (*s == '/' && maskptr && *maskptr != 0) ? yield : 0;
+int
+string_is_ip_address(const uschar *ip_addr, int *maskptr) {
+ return string_is_ip_addressX(ip_addr, maskptr, 0);
}
+
#endif /* COMPILE_UTILITY */
git://git.exim.org / exim.git / blobdiff