+
+
+int odhcpd_netmask2bitlen(bool inet6, void *mask)
+{
+ int bits;
+ struct in_addr *v4;
+ struct in6_addr *v6;
+
+ if (inet6)
+ for (bits = 0, v6 = mask;
+ bits < 128 && (v6->s6_addr[bits / 8] << (bits % 8)) & 128;
+ bits++);
+ else
+ for (bits = 0, v4 = mask;
+ bits < 32 && (ntohl(v4->s_addr) << bits) & 0x80000000;
+ bits++);
+
+ return bits;
+}
+
+bool odhcpd_bitlen2netmask(bool inet6, unsigned int bits, void *mask)
+{
+ uint8_t b;
+ struct in_addr *v4;
+ struct in6_addr *v6;
+
+ if (inet6)
+ {
+ if (bits > 128)
+ return false;
+
+ v6 = mask;
+
+ for (unsigned int i = 0; i < sizeof(v6->s6_addr); i++)
+ {
+ b = (bits > 8) ? 8 : bits;
+ v6->s6_addr[i] = (uint8_t)(0xFF << (8 - b));
+ bits -= b;
+ }
+ }
+ else
+ {
+ if (bits > 32)
+ return false;
+
+ v4 = mask;
+ v4->s_addr = bits ? htonl(~((1 << (32 - bits)) - 1)) : 0;
+ }
+
+ return true;
+}
+
+bool odhcpd_valid_hostname(const char *name)
+{
+#define MAX_LABEL 63
+ const char *c, *label, *label_end;
+ int label_sz = 0;
+
+ for (c = name, label_sz = 0, label = name, label_end = name + strcspn(name, ".") - 1;
+ *c && label_sz <= MAX_LABEL; c++) {
+ if ((*c >= '0' && *c <= '9') ||
+ (*c >= 'A' && *c <= 'Z') ||
+ (*c >= 'a' && *c <= 'z')) {
+ label_sz++;
+ continue;
+ }
+
+ if ((*c == '_' || *c == '-') && c != label && c != label_end) {
+ label_sz++;
+ continue;
+ }
+
+ if (*c == '.') {
+ if (*(c + 1)) {
+ label = c + 1;
+ label_end = label + strcspn(label, ".") - 1;
+ label_sz = 0;
+ }
+ continue;
+ }
+
+ return false;
+ }
+
+ return (label_sz && label_sz <= MAX_LABEL ? true : false);
+}