+#define WTMPFILE "/usr/adm/wtmp"
+
+int
+logwtmp(line, name, host)
+ char *line, *name, *host;
+{
+ int fd;
+ struct stat buf;
+ struct utmp ut;
+
+ if ((fd = open(WTMPFILE, O_WRONLY|O_APPEND, 0)) < 0)
+ return;
+ if (!fstat(fd, &buf)) {
+ (void)strncpy(ut.ut_line, line, sizeof(ut.ut_line));
+ (void)strncpy(ut.ut_name, name, sizeof(ut.ut_name));
+ (void)strncpy(ut.ut_host, host, sizeof(ut.ut_host));
+ (void)time(&ut.ut_time);
+ if (write(fd, (char *)&ut, sizeof(struct utmp)) != sizeof(struct utmp))
+ (void)ftruncate(fd, buf.st_size);
+ }
+ close(fd);
+}
+
+/*
+ * Return user specified netmask, modified by any mask we might determine
+ * for address `addr' (in network byte order).
+ * Here we scan through the system's list of interfaces, looking for
+ * any non-point-to-point interfaces which might appear to be on the same
+ * network as `addr'. If we find any, we OR in their netmask to the
+ * user-specified netmask.
+ */
+u_int32_t
+GetMask(addr)
+ u_int32_t addr;
+{
+ u_int32_t mask, nmask, ina;
+ struct ifreq *ifr, *ifend, ifreq;
+ struct ifconf ifc;
+ struct ifreq ifs[MAX_IFS];
+
+ addr = ntohl(addr);
+ if (IN_CLASSA(addr)) /* determine network mask for address class */
+ nmask = IN_CLASSA_NET;
+ else if (IN_CLASSB(addr))
+ nmask = IN_CLASSB_NET;
+ else
+ nmask = IN_CLASSC_NET;
+ /* class D nets are disallowed by bad_ip_adrs */
+ mask = netmask | htonl(nmask);
+
+ /*
+ * Scan through the system's network interfaces.
+ */
+ ifc.ifc_len = sizeof(ifs);
+ ifc.ifc_req = ifs;
+ if (ioctl(sockfd, SIOCGIFCONF, &ifc) < 0) {
+ syslog(LOG_WARNING, "ioctl(SIOCGIFCONF): %m");
+ return mask;
+ }
+ ifend = (struct ifreq *) (ifc.ifc_buf + ifc.ifc_len);
+ for (ifr = ifc.ifc_req; ifr < ifend; ifr = (struct ifreq *)
+ ((char *)&ifr->ifr_addr + ifr->ifr_addr.sa_len)) {
+ /*
+ * Check the interface's internet address.
+ */
+ if (ifr->ifr_addr.sa_family != AF_INET)
+ continue;
+ ina = ((struct sockaddr_in *) &ifr->ifr_addr)->sin_addr.s_addr;
+ if ((ntohl(ina) & nmask) != (addr & nmask))
+ continue;
+ /*
+ * Check that the interface is up, and not point-to-point or loopback.
+ */
+ strncpy(ifreq.ifr_name, ifr->ifr_name, sizeof(ifreq.ifr_name));
+ if (ioctl(sockfd, SIOCGIFFLAGS, &ifreq) < 0)
+ continue;
+ if ((ifreq.ifr_flags & (IFF_UP|IFF_POINTOPOINT|IFF_LOOPBACK))
+ != IFF_UP)
+ continue;
+ /*
+ * Get its netmask and OR it into our mask.
+ */
+ if (ioctl(sockfd, SIOCGIFNETMASK, &ifreq) < 0)
+ continue;
+ mask |= ((struct sockaddr_in *)&ifreq.ifr_addr)->sin_addr.s_addr;
+ }
+
+ return mask;
+}