+ /* Intentionally no support for bizarre IPv4 formats (plain
+ * integers, octal or hex components) -- only vanilla dotted
+ * decimal quads.
+ */
+ if (input[0] == '.')
+ return 0;
+ bits = 32;
+ while (1) switch (input[pos]) {
+ case '\0':
+ if (dots < 3)
+ return 0;
+ out:
+ ip |= part << (24 - 8 * dots);
+ *output = htonl(ip);
+ if (pbits)
+ *pbits = bits;
+ return pos;
+ case '.':
+ if (++dots > 3)
+ return 0;
+ if (input[++pos] == '.')
+ return 0;
+ ip |= part << (32 - 8 * dots);
+ part = 0;
+ if (input[pos] == '*') {
+ while (input[++pos] == '*' || input[pos] == '.') ;
+ if (input[pos] != '\0')
+ return 0;
+ if (pbits)
+ *pbits = dots * 8;
+ *output = htonl(ip);
+ return pos;
+ }
+ break;
+ case '/':
+ if (!pbits || !IsDigit(input[pos + 1]))
+ return 0;
+ for (bits = 0; IsDigit(input[++pos]); )
+ bits = bits * 10 + input[pos] - '0';
+ if (bits > 32)
+ return 0;
+ goto out;
+ case '0': case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9':
+ part = part * 10 + input[pos++] - '0';
+ if (part > 255)
+ return 0;
+ break;
+ default:
+ return 0;
+ }
+}
+
+/** Parse a numeric IPv4 or IPv6 address into an irc_in_addr.
+ * @param[in] input Input buffer.
+ * @param[out] ip Receives parsed IP address.
+ * @param[out] pbits If non-NULL, receives number of bits specified in address mask.
+ * @return Number of characters used from \a input, or 0 if the
+ * address was unparseable or malformed.
+ */
+int
+ipmask_parse(const char *input, struct irc_in_addr *ip, unsigned char *pbits)
+{
+ char *colon;
+ char *dot;
+
+ assert(ip);
+ assert(input);
+ memset(ip, 0, sizeof(*ip));
+ colon = strchr(input, ':');
+ dot = strchr(input, '.');
+
+ if (colon && (!dot || (dot > colon))) {
+ unsigned int part = 0, pos = 0, ii = 0, colon = 8;
+ const char *part_start = NULL;
+
+ /* Parse IPv6, possibly like ::127.0.0.1.
+ * This is pretty straightforward; the only trick is borrowed
+ * from Paul Vixie (BIND): when it sees a "::" continue as if
+ * it were a single ":", but note where it happened, and fill
+ * with zeros afterward.
+ */
+ if (input[pos] == ':') {
+ if ((input[pos+1] != ':') || (input[pos+2] == ':'))
+ return 0;
+ colon = 0;
+ pos += 2;
+ part_start = input + pos;
+ }
+ while (ii < 8) switch (input[pos]) {
+ unsigned char chval;
+ case '0': case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9':
+ chval = input[pos] - '0';
+ use_chval:
+ part = (part << 4) | chval;
+ if (part > 0xffff)
+ return 0;
+ pos++;
+ break;
+ case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
+ chval = input[pos] - 'A' + 10;
+ goto use_chval;
+ case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
+ chval = input[pos] - 'a' + 10;
+ goto use_chval;
+ case ':':
+ part_start = input + ++pos;
+ if (input[pos] == '.')
+ return 0;
+ ip->in6_16[ii++] = htons(part);
+ part = 0;
+ if (input[pos] == ':') {
+ if (colon < 8)
+ return 0;
+ if (ii == 8)
+ return 0;
+ colon = ii;
+ pos++;
+ }
+ break;
+ case '.': {
+ uint32_t ip4;
+ unsigned int len;
+ len = ircd_aton_ip4(part_start, &ip4, pbits);
+ if (!len || (ii > 6))
+ return 0;
+ ip->in6_16[ii++] = htons(ntohl(ip4) >> 16);
+ ip->in6_16[ii++] = htons(ntohl(ip4) & 65535);
+ if (pbits)
+ *pbits += 96;
+ pos = part_start + len - input;
+ goto finish;
+ }
+ case '/':
+ if (!pbits || !IsDigit(input[pos + 1]))
+ return 0;
+ ip->in6_16[ii++] = htons(part);
+ for (part = 0; IsDigit(input[++pos]); )
+ part = part * 10 + input[pos] - '0';
+ if (part > 128)
+ return 0;
+ *pbits = part;
+ goto finish;
+ case '*':
+ while (input[++pos] == '*' || input[pos] == ':') ;
+ if (input[pos] != '\0' || colon < 8)
+ return 0;
+ if (part && ii < 8)
+ ip->in6_16[ii++] = htons(part);
+ if (pbits)
+ *pbits = ii * 16;
+ return pos;
+ case '\0':
+ ip->in6_16[ii++] = htons(part);
+ if (colon == 8 && ii < 8)
+ return 0;
+ if (pbits)
+ *pbits = 128;
+ goto finish;
+ default:
+ return 0;
+ }
+ if (input[pos] != '\0')
+ return 0;
+ finish:
+ if (colon < 8) {
+ unsigned int jj;
+ /* Shift stuff after "::" up and fill middle with zeros. */
+ for (jj = 0; jj < ii - colon; jj++)
+ ip->in6_16[7 - jj] = ip->in6_16[ii - jj - 1];
+ for (jj = 0; jj < 8 - ii; jj++)
+ ip->in6_16[colon + jj] = 0;
+ }
+ return pos;
+ } else if (dot || strchr(input, '/')) {
+ unsigned int addr;
+ int len = ircd_aton_ip4(input, &addr, pbits);
+ if (len) {
+ ip->in6_16[5] = htons(65535);
+ ip->in6_16[6] = htons(ntohl(addr) >> 16);
+ ip->in6_16[7] = htons(ntohl(addr) & 65535);
+ if (pbits)
+ *pbits += 96;
+ }
+ return len;
+ } else if (input[0] == '*') {
+ unsigned int pos = 0;
+ while (input[++pos] == '*') ;
+ if (input[pos] != '\0')
+ return 0;
+ if (pbits)
+ *pbits = 0;
+ return pos;
+ } else return 0; /* parse failed */
+}