+
+unsigned int
+parse_netmask_string(const char *str, bool v6)
+{
+ struct in_addr addr;
+ unsigned int ret;
+ char *err = NULL;
+
+ if (!strchr(str, '.')) {
+ ret = strtoul(str, &err, 0);
+ if (err && *err)
+ goto error;
+
+ return ret;
+ }
+
+ if (v6)
+ goto error;
+
+ if (inet_aton(str, &addr) != 1)
+ goto error;
+
+ return 32 - fls(~(ntohl(addr.s_addr)));
+
+error:
+ return ~0;
+}
+
+bool
+split_netmask(char *str, unsigned int *netmask, bool v6)
+{
+ char *delim = strchr(str, '/');
+
+ if (delim) {
+ *(delim++) = 0;
+
+ *netmask = parse_netmask_string(delim, v6);
+ }
+ return true;
+}
+
+int
+parse_ip_and_netmask(int af, const char *str, void *addr, unsigned int *netmask)
+{
+ char *astr = alloca(strlen(str) + 1);
+
+ strcpy(astr, str);
+ if (!split_netmask(astr, netmask, af == AF_INET6))
+ return 0;
+
+ if (af == AF_INET6) {
+ if (*netmask > 128)
+ return 0;
+ } else {
+ if (*netmask > 32)
+ return 0;
+ }
+
+ return inet_pton(af, astr, addr);
+}
+
+char *
+format_macaddr(uint8_t *mac)
+{
+ static char str[sizeof("ff:ff:ff:ff:ff:ff ")];
+
+ snprintf(str, sizeof(str), "%02x:%02x:%02x:%02x:%02x:%02x",
+ mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+
+ return str;
+}
+
+uint32_t
+crc32_file(FILE *fp)
+{
+ static uint32_t *crcvals = NULL;
+ if (!crcvals) {
+ crcvals = malloc(sizeof(*crcvals) * 256);
+
+ for (size_t i = 0; i < 256; ++i) {
+ uint32_t c = i;
+ for (size_t j = 0; j < 8; ++j)
+ c = (c & 1) ? (0xEDB88320 ^ (c >> 1)) : (c >> 1);
+ crcvals[i] = c;
+ }
+ }
+
+ uint8_t buf[1024];
+ size_t len;
+ uint32_t c = 0xFFFFFFFF;
+
+ do {
+ len = fread(buf, 1, sizeof(buf), fp);
+ for (size_t i = 0; i < len; ++i)
+ c = crcvals[(c ^ buf[i]) & 0xFF] ^ (c >> 8);
+ } while (len == sizeof(buf));
+
+ return c ^ 0xFFFFFFFF;
+}