if (start && end && start < end &&
start > ntohl(addr.s_addr & ~mask.s_addr) &&
- (start & ntohl(mask.s_addr)) == start &&
- (end & ntohl(mask.s_addr)) == end) {
+ (start & ntohl(~mask.s_addr)) == start &&
+ (end & ntohl(~mask.s_addr)) == end) {
iface->dhcpv4_start.s_addr = htonl(start) |
(addr.s_addr & mask.s_addr);
iface->dhcpv4_end.s_addr = htonl(end) |
struct sockaddr_in dest = *((struct sockaddr_in*)addr);
if (req->giaddr.s_addr) {
+ /*
+ * relay agent is configured, send reply to the agent
+ */
dest.sin_addr = req->giaddr;
dest.sin_port = htons(DHCPV4_SERVER_PORT);
} else if (req->ciaddr.s_addr && req->ciaddr.s_addr != dest.sin_addr.s_addr) {
+ /*
+ * client has existing configuration (ciaddr is set) AND this address is
+ * not the address it used for the dhcp message
+ */
dest.sin_addr = req->ciaddr;
dest.sin_port = htons(DHCPV4_CLIENT_PORT);
} else if ((ntohs(req->flags) & DHCPV4_FLAG_BROADCAST) ||
req->hlen != reply.hlen || !reply.yiaddr.s_addr) {
+ /*
+ * client requests a broadcast reply OR we can't offer an IP
+ */
+ dest.sin_addr.s_addr = INADDR_BROADCAST;
+ dest.sin_port = htons(DHCPV4_CLIENT_PORT);
+ } else if (!req->ciaddr.s_addr && msg == DHCPV4_MSG_NAK) {
+ /*
+ * client has no previous configuration -> no IP, so we need to reply
+ * with a broadcast packet
+ */
dest.sin_addr.s_addr = INADDR_BROADCAST;
dest.sin_port = htons(DHCPV4_CLIENT_PORT);
} else {
+ /*
+ * send reply to the newly (in this proccess) allocated IP
+ */
dest.sin_addr = reply.yiaddr;
dest.sin_port = htons(DHCPV4_CLIENT_PORT);
ioctl(sock, SIOCSARP, &arp);
}
- syslog(LOG_WARNING, "sending %s to %x:%x:%x:%x:%x:%x",
- dhcpv4_msg_to_string(msg),
- req->chaddr[0],req->chaddr[1],req->chaddr[2],
- req->chaddr[3],req->chaddr[4],req->chaddr[5]);
+ if (dest.sin_addr.s_addr == INADDR_BROADCAST) {
+ /*
+ * reply goes to IP broadcast -> MAC broadcast
+ */
+ syslog(LOG_WARNING, "sending %s to ff:ff:ff:ff:ff:ff - %s",
+ dhcpv4_msg_to_string(msg),
+ inet_ntoa(dest.sin_addr));
+ } else {
+ /*
+ * reply is send directly to IP,
+ * MAC is assumed to be the same as the request
+ */
+ syslog(LOG_WARNING, "sending %s to %x:%x:%x:%x:%x:%x - %s",
+ dhcpv4_msg_to_string(msg),
+ req->chaddr[0],req->chaddr[1],req->chaddr[2],
+ req->chaddr[3],req->chaddr[4],req->chaddr[5],
+ inet_ntoa(dest.sin_addr));
+ }
sendto(sock, &reply, sizeof(reply), MSG_DONTWAIT,
(struct sockaddr*)&dest, sizeof(dest));
if (assigned && a)
lease = a;
} else if (msg == DHCPV4_MSG_RELEASE) {
- if (a) {
+ if (a && a->valid_until != LONG_MAX)
a->valid_until = 0;
- }
- } else if (msg == DHCPV4_MSG_DECLINE) {
+ } else if (msg == DHCPV4_MSG_DECLINE && a->valid_until != LONG_MAX) {
memset(a->hwaddr, 0, sizeof(a->hwaddr));
a->valid_until = now + 3600; // Block address for 1h
}