dhcpv4: dhcpv4: move interface lease list insertion out of dhcpv4_assign
[project/odhcpd.git] / src / dhcpv4.c
index 99ad658..db900c1 100644 (file)
@@ -1,5 +1,6 @@
 /**
  * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
+ * Copyright (C) 2016 Hans Dedecker <dedeckeh@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License v2 as published by
 #include "dhcpv4.h"
 #include "dhcpv6.h"
 
-
+static void free_dhcpv4_assignment(struct dhcpv4_assignment *a);
 static void handle_dhcpv4(void *addr, void *data, size_t len,
                struct interface *iface, void *dest_addr);
 static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface,
                enum dhcpv4_msg msg, const uint8_t *mac, struct in_addr reqaddr,
-               const char *hostname);
+               uint32_t *leasetime, const char *hostname, const size_t hostname_len);
 
-// Create socket and register events
+/* Create socket and register events */
 int init_dhcpv4(void)
 {
        return 0;
 }
 
-char *dhcpv4_msg_to_string(uint8_t reqmsg)
-{
-       switch (reqmsg) {
-       case (DHCPV4_MSG_DISCOVER):
-               return "DHCPV4_MSG_DISCOVER";
-       case (DHCPV4_MSG_OFFER):
-               return "DHCPV4_MSG_OFFER";
-       case (DHCPV4_MSG_REQUEST):
-               return "DHCPV4_MSG_REQUEST";
-       case (DHCPV4_MSG_DECLINE):
-               return "DHCPV4_MSG_DECLINE";
-       case (DHCPV4_MSG_ACK):
-               return "DHCPV4_MSG_ACK";
-       case (DHCPV4_MSG_NAK):
-               return "DHCPV4_MSG_NAK";
-       case (DHCPV4_MSG_RELEASE):
-               return "DHCPV4_MSG_RELEASE";
-       case (DHCPV4_MSG_INFORM):
-               return "DHCPV4_MSG_INFORM";
-       default:
-               return "UNKNOWN";
-       }
-}
-
 int setup_dhcpv4_interface(struct interface *iface, bool enable)
 {
        if (iface->dhcpv4_event.uloop.fd > 0) {
@@ -88,7 +65,7 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable)
                        return -1;
                }
 
-               // Basic IPv6 configuration
+               /* Basic IPv4 configuration */
                int val = 1;
                setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
                setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &val, sizeof(val));
@@ -118,37 +95,36 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable)
                        return -1;
                }
 
-               // Create a range if not specified
-               if (!(iface->dhcpv4_start.s_addr & htonl(0xffff0000)) &&
-                               !(iface->dhcpv4_end.s_addr & htonl(0xffff0000))) {
+               uint32_t mask = iface->addr4[0].prefix ? htonl(~((1 << (32 - iface->addr4[0].prefix)) - 1)) : 0;
 
-                       struct in_addr *saddr = ubus_get_address4(iface->name);
-                       struct in_addr addr = { .s_addr = saddr->s_addr } ;
-                       struct in_addr *smask = ubus_get_mask4(iface->name);
-                       struct in_addr mask = { .s_addr = smask->s_addr } ;
+               /* Create a range if not specified */
+               if (!(iface->dhcpv4_start.s_addr & htonl(0xffff0000)) &&
+                               !(iface->dhcpv4_end.s_addr & htonl(0xffff0000)) &&
+                               iface->addr4_len) {
+                       struct in_addr *addr = &iface->addr4[0].addr.in;
 
                        uint32_t start = ntohl(iface->dhcpv4_start.s_addr);
                        uint32_t end = ntohl(iface->dhcpv4_end.s_addr);
 
                        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(addr->s_addr & ~mask) &&
+                                       (start & ntohl(~mask)) == start &&
+                                       (end & ntohl(~mask)) == end) {
                                iface->dhcpv4_start.s_addr = htonl(start) |
-                                               (addr.s_addr & mask.s_addr);
+                                               (addr->s_addr & mask);
                                iface->dhcpv4_end.s_addr = htonl(end) |
-                                               (addr.s_addr & mask.s_addr);
-                       } else if (ntohl(mask.s_addr) <= 0xfffffff0) {
-                               start = addr.s_addr & mask.s_addr;
-                               end = addr.s_addr & mask.s_addr;
+                                               (addr->s_addr & mask);
+                       } else if (ntohl(mask) <= 0xfffffff0) {
+                               start = addr->s_addr & mask;
+                               end = addr->s_addr & mask;
 
-                               if (ntohl(mask.s_addr) <= 0xffffff00) {
+                               if (ntohl(mask) <= 0xffffff00) {
                                        iface->dhcpv4_start.s_addr = start | htonl(100);
                                        iface->dhcpv4_end.s_addr = end | htonl(250);
-                               } else if (ntohl(mask.s_addr) <= 0xffffffc0) {
+                               } else if (ntohl(mask) <= 0xffffffc0) {
                                        iface->dhcpv4_start.s_addr = start | htonl(10);
                                        iface->dhcpv4_end.s_addr = end | htonl(60);
-                               } else if (ntohl(mask.s_addr) <= 0xffffffe0) {
+                               } else if (ntohl(mask) <= 0xffffffe0) {
                                        iface->dhcpv4_start.s_addr = start | htonl(10);
                                        iface->dhcpv4_end.s_addr = end | htonl(30);
                                } else {
@@ -156,76 +132,102 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable)
                                        iface->dhcpv4_end.s_addr = end | htonl(12);
                                }
                        }
-
-
                }
 
-               // Parse static entries
+               /* Parse static entries */
                struct lease *lease;
                list_for_each_entry(lease, &leases, head) {
-                       // Construct entry
-                       size_t hostlen = strlen(lease->hostname) + 1;
-                       struct dhcpv4_assignment *a = calloc(1, sizeof(*a) + hostlen);
+                       /* Construct entry */
+                       struct dhcpv4_assignment *a = calloc(1, sizeof(*a));
                        if (!a) {
                                syslog(LOG_ERR, "Calloc failed for static lease on interface %s",
                                        iface->ifname);
                                return -1;
                        }
+
+                       a->leasetime = lease->dhcpv4_leasetime;
+
                        a->addr = ntohl(lease->ipaddr.s_addr);
                        memcpy(a->hwaddr, lease->mac.ether_addr_octet, sizeof(a->hwaddr));
-                       memcpy(a->hostname, lease->hostname, hostlen);
-                       a->valid_until = LONG_MAX;
+                       /* Static assignment */
+                       a->flags |= OAF_STATIC;
+                       /* Infinite valid */
+                       a->valid_until = 0;
 
-                       // Assign to all interfaces
+                       /* Assign to all interfaces */
                        struct dhcpv4_assignment *c;
                        list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
                                if (c->addr > a->addr) {
                                        list_add_tail(&a->head, &c->head);
                                        break;
-                               } else if (c->addr == a->addr) {
-                                       // Already an assignment with that number
+                               } else if (c->addr == a->addr)
+                                       /* Already an assignment with that number */
                                        break;
-                               }
                        }
-                       if (&c->head == &iface->dhcpv4_assignments) {
+
+                       if (&c->head == &iface->dhcpv4_assignments)
                                list_add(&a->head, &iface->dhcpv4_assignments);
-                       }
 
-                       if (!a->head.next)
-                               free(a);
+                       if (a->head.next) {
+                               if (lease->hostname[0]) {
+                                       free(a->hostname);
+                                       a->hostname = strdup(lease->hostname);
+                               }
+                       } else
+                               free_dhcpv4_assignment(a);
                }
 
                // Clean invalid assignments
                struct dhcpv4_assignment *a, *n;
-               struct in_addr *smask = ubus_get_mask4(iface->name);
-               struct in_addr mask = { .s_addr = smask->s_addr } ;
                list_for_each_entry_safe(a, n, &iface->dhcpv4_assignments, head) {
-                       if ((htonl(a->addr) & mask.s_addr) !=
-                                       (iface->dhcpv4_start.s_addr & mask.s_addr)) {
-                               list_del(&a->head);
-                               free(a);
-                       }
+                       if ((htonl(a->addr) & mask) !=
+                                       (iface->dhcpv4_start.s_addr & mask))
+                               free_dhcpv4_assignment(a);
                }
 
-
-               if (iface->dhcpv4_leasetime < 60)
-                       iface->dhcpv4_leasetime = 43200;
-
                iface->dhcpv4_event.uloop.fd = sock;
                iface->dhcpv4_event.handle_dgram = handle_dhcpv4;
                odhcpd_register(&iface->dhcpv4_event);
        } else if (iface->dhcpv4_assignments.next) {
-               while (!list_empty(&iface->dhcpv4_assignments)) {
-                       struct dhcpv4_assignment *a = list_first_entry(&iface->dhcpv4_assignments,
-                                       struct dhcpv4_assignment, head);
-                       list_del(&a->head);
-                       free(a);
-               }
-
+               while (!list_empty(&iface->dhcpv4_assignments))
+                       free_dhcpv4_assignment(list_first_entry(&iface->dhcpv4_assignments,
+                                                       struct dhcpv4_assignment, head));
        }
        return 0;
 }
 
+static char *dhcpv4_msg_to_string(uint8_t reqmsg)
+{
+       switch (reqmsg) {
+       case (DHCPV4_MSG_DISCOVER):
+               return "DHCPV4_MSG_DISCOVER";
+       case (DHCPV4_MSG_OFFER):
+               return "DHCPV4_MSG_OFFER";
+       case (DHCPV4_MSG_REQUEST):
+               return "DHCPV4_MSG_REQUEST";
+       case (DHCPV4_MSG_DECLINE):
+               return "DHCPV4_MSG_DECLINE";
+       case (DHCPV4_MSG_ACK):
+               return "DHCPV4_MSG_ACK";
+       case (DHCPV4_MSG_NAK):
+               return "DHCPV4_MSG_NAK";
+       case (DHCPV4_MSG_RELEASE):
+               return "DHCPV4_MSG_RELEASE";
+       case (DHCPV4_MSG_INFORM):
+               return "DHCPV4_MSG_INFORM";
+       default:
+               return "UNKNOWN";
+       }
+}
+
+static void free_dhcpv4_assignment(struct dhcpv4_assignment *a)
+{
+       if (a->head.next)
+               list_del(&a->head);
+
+       free(a->hostname);
+       free(a);
+}
 
 static void dhcpv4_put(struct dhcpv4_message *msg, uint8_t **cookie,
                uint8_t type, uint8_t len, const void *data)
@@ -241,8 +243,7 @@ static void dhcpv4_put(struct dhcpv4_message *msg, uint8_t **cookie,
        *cookie = c + len;
 }
 
-
-// Simple DHCPv6-server for information requests
+// Handler for DHCPv4 messages
 static void handle_dhcpv4(void *addr, void *data, size_t len,
                struct interface *iface, _unused void *dest_addr)
 {
@@ -254,35 +255,26 @@ static void handle_dhcpv4(void *addr, void *data, size_t len,
                        req->op != DHCPV4_BOOTREQUEST || req->hlen != 6)
                return;
 
-       int sock = iface->dhcpv4_event.uloop.fd;
-       struct sockaddr_in ifaddr;
-       struct sockaddr_in ifnetmask;
 
        syslog(LOG_NOTICE, "Got DHCPv4 request");
 
-       struct ifreq ifreq;
-       memcpy(ifreq.ifr_name, iface->ifname, sizeof(ifreq.ifr_name));
-       if (ioctl(sock, SIOCGIFADDR, &ifreq)) {
-               syslog(LOG_WARNING, "DHCPv4 failed to detect address: %s", strerror(errno));
+       if (!iface->addr4_len) {
+               syslog(LOG_WARNING, "DHCPv4 no address found on %s", iface->name);
                return;
        }
 
-       memcpy(&ifaddr, &ifreq.ifr_addr, sizeof(ifaddr));
-       if (ioctl(sock, SIOCGIFNETMASK, &ifreq))
-               return;
-
-       memcpy(&ifnetmask, &ifreq.ifr_netmask, sizeof(ifnetmask));
-       uint32_t network = ifaddr.sin_addr.s_addr & ifnetmask.sin_addr.s_addr;
+       struct in_addr *ifaddr = &iface->addr4[0].addr.in;
+       struct in_addr *ifbroadcast = &iface->addr4[0].broadcast;
+       uint32_t mask = iface->addr4[0].prefix ? htonl(~((1 << (32 - iface->addr4[0].prefix)) - 1)) : 0;
+       uint32_t network = iface->addr4[0].addr.in.s_addr & mask;
+       int sock = iface->dhcpv4_event.uloop.fd;
 
-       if ((iface->dhcpv4_start.s_addr & ifnetmask.sin_addr.s_addr) != network ||
-                       (iface->dhcpv4_end.s_addr & ifnetmask.sin_addr.s_addr) != network) {
+       if ((iface->dhcpv4_start.s_addr & mask) != network ||
+                       (iface->dhcpv4_end.s_addr & mask) != network) {
                syslog(LOG_WARNING, "DHCPv4 range out of assigned network");
                return;
        }
 
-       struct ifreq ifr = {.ifr_name = ""};
-       strncpy(ifr.ifr_name, iface->ifname, sizeof(ifr.ifr_name));
-
        struct dhcpv4_message reply = {
                .op = DHCPV4_BOOTREPLY,
                .htype = 1,
@@ -293,7 +285,7 @@ static void handle_dhcpv4(void *addr, void *data, size_t len,
                .flags = req->flags,
                .ciaddr = {INADDR_ANY},
                .giaddr = req->giaddr,
-               .siaddr = ifaddr.sin_addr,
+               .siaddr = *ifaddr,
        };
        memcpy(reply.chaddr, req->chaddr, sizeof(reply.chaddr));
 
@@ -307,22 +299,24 @@ static void handle_dhcpv4(void *addr, void *data, size_t len,
        uint8_t msg = DHCPV4_MSG_ACK;
 
        struct in_addr reqaddr = {INADDR_ANY};
+       uint32_t leasetime = 0;
+       size_t hostname_len = 0;
        char hostname[256];
-       hostname[0] = 0;
 
        uint8_t *start = &req->options[4];
        uint8_t *end = ((uint8_t*)data) + len;
        struct dhcpv4_option *opt;
        dhcpv4_for_each_option(start, end, opt) {
-               if (opt->type == DHCPV4_OPT_MESSAGE && opt->len == 1) {
+               if (opt->type == DHCPV4_OPT_MESSAGE && opt->len == 1)
                        reqmsg = opt->data[0];
-               } else if (opt->type == DHCPV4_OPT_HOSTNAME && opt->len > 0) {
-                       memcpy(hostname, opt->data, opt->len);
-                       hostname[opt->len] = 0;
-               } else if (opt->type == DHCPV4_OPT_IPADDRESS && opt->len == 4) {
+               else if (opt->type == DHCPV4_OPT_HOSTNAME && opt->len > 0) {
+                       hostname_len = opt->len;
+                       memcpy(hostname, opt->data, hostname_len);
+                       hostname[hostname_len] = 0;
+               } else if (opt->type == DHCPV4_OPT_IPADDRESS && opt->len == 4)
                        memcpy(&reqaddr, opt->data, 4);
-               else if (opt->type == DHCPV4_OPT_SERVERID && opt->len == 4) {
-                       if (memcmp(opt->data, &ifaddr.sin_addr, 4))
+               else if (opt->type == DHCPV4_OPT_SERVERID && opt->len == 4) {
+                       if (memcmp(opt->data, ifaddr, 4))
                                return;
                } else if (iface->filter_class && opt->type == DHCPV4_OPT_USER_CLASS) {
                        uint8_t *c = opt->data, *cend = &opt->data[opt->len];
@@ -331,7 +325,8 @@ static void handle_dhcpv4(void *addr, void *data, size_t len,
                                if (*c == elen && !memcmp(&c[1], iface->filter_class, elen))
                                        return; // Ignore from homenet
                        }
-               }
+               } else if (opt->type == DHCPV4_OPT_LEASETIME && opt->len == 4)
+                       memcpy(&leasetime, opt->data, 4);
        }
 
        if (reqmsg != DHCPV4_MSG_DISCOVER && reqmsg != DHCPV4_MSG_REQUEST &&
@@ -341,16 +336,17 @@ static void handle_dhcpv4(void *addr, void *data, size_t len,
 
        struct dhcpv4_assignment *lease = NULL;
        if (reqmsg != DHCPV4_MSG_INFORM)
-               lease = dhcpv4_lease(iface, reqmsg, req->chaddr, reqaddr, hostname);
+               lease = dhcpv4_lease(iface, reqmsg, req->chaddr, reqaddr,
+                                       &leasetime, hostname, hostname_len);
 
        if (!lease) {
                if (reqmsg == DHCPV4_MSG_REQUEST)
                        msg = DHCPV4_MSG_NAK;
                else if (reqmsg == DHCPV4_MSG_DISCOVER)
                        return;
-       } else if (reqmsg == DHCPV4_MSG_DISCOVER) {
+       } else if (reqmsg == DHCPV4_MSG_DISCOVER)
                msg = DHCPV4_MSG_OFFER;
-       else if (reqmsg == DHCPV4_MSG_REQUEST && reqaddr.s_addr &&
+       else if (reqmsg == DHCPV4_MSG_REQUEST && reqaddr.s_addr &&
                        reqaddr.s_addr != htonl(lease->addr)) {
                msg = DHCPV4_MSG_NAK;
                /*
@@ -365,7 +361,7 @@ static void handle_dhcpv4(void *addr, void *data, size_t len,
                 */
        }
 
-       syslog(LOG_WARNING, "received %s from %x:%x:%x:%x:%x:%x",
+       syslog(LOG_WARNING, "received %s from %02x:%02x:%02x:%02x:%02x:%02x",
                        dhcpv4_msg_to_string(reqmsg),
                        req->chaddr[0],req->chaddr[1],req->chaddr[2],
                        req->chaddr[3],req->chaddr[4],req->chaddr[5]);
@@ -374,41 +370,46 @@ static void handle_dhcpv4(void *addr, void *data, size_t len,
                return;
 
        dhcpv4_put(&reply, &cookie, DHCPV4_OPT_MESSAGE, 1, &msg);
-       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_SERVERID, 4, &ifaddr.sin_addr);
+       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_SERVERID, 4, ifaddr);
 
        if (lease) {
+               uint32_t val;
+
                reply.yiaddr.s_addr = htonl(lease->addr);
 
-               uint32_t val = htonl(iface->dhcpv4_leasetime);
+               val = htonl(leasetime);
                dhcpv4_put(&reply, &cookie, DHCPV4_OPT_LEASETIME, 4, &val);
 
-               val = htonl(500 * iface->dhcpv4_leasetime / 1000);
-               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_RENEW, 4, &val);
+               if (leasetime != UINT32_MAX) {
+                       val = htonl(500 * leasetime / 1000);
+                       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_RENEW, 4, &val);
 
-               val = htonl(875 * iface->dhcpv4_leasetime / 1000);
-               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_REBIND, 4, &val);
+                       val = htonl(875 * leasetime / 1000);
+                       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_REBIND, 4, &val);
+               }
 
-               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_NETMASK, 4, &ifnetmask.sin_addr);
+               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_NETMASK, 4, &mask);
 
-               if (lease->hostname[0])
+               if (lease->hostname)
                        dhcpv4_put(&reply, &cookie, DHCPV4_OPT_HOSTNAME,
                                        strlen(lease->hostname), lease->hostname);
 
-               if (!ioctl(sock, SIOCGIFBRDADDR, &ifr)) {
-                       struct sockaddr_in *ina = (struct sockaddr_in*)&ifr.ifr_broadaddr;
-                       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_BROADCAST, 4, &ina->sin_addr);
-               }
+               if (ifbroadcast->s_addr != INADDR_ANY)
+                       dhcpv4_put(&reply, &cookie, DHCPV4_OPT_BROADCAST, 4, ifbroadcast);
        }
 
+       struct ifreq ifr = {.ifr_name = ""};
+       strncpy(ifr.ifr_name, iface->ifname, sizeof(ifr.ifr_name));
+
        if (!ioctl(sock, SIOCGIFMTU, &ifr)) {
                uint16_t mtu = htons(ifr.ifr_mtu);
                dhcpv4_put(&reply, &cookie, DHCPV4_OPT_MTU, 2, &mtu);
        }
 
-       if (iface->search && iface->search_len <= 255) {
+       if (iface->search && iface->search_len <= 255)
                dhcpv4_put(&reply, &cookie, DHCPV4_OPT_SEARCH_DOMAIN,
                                iface->search_len, iface->search);
-       else if (!res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) {
+       else if (!res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) {
                uint8_t search_buf[256];
                int len = dn_comp(_res.dnsrch[0], search_buf,
                                                sizeof(search_buf), NULL, NULL);
@@ -418,14 +419,14 @@ static void handle_dhcpv4(void *addr, void *data, size_t len,
        }
 
        if (iface->dhcpv4_router_cnt == 0)
-               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_ROUTER, 4, &ifaddr.sin_addr);
+               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_ROUTER, 4, ifaddr);
        else
                dhcpv4_put(&reply, &cookie, DHCPV4_OPT_ROUTER,
                                4 * iface->dhcpv4_router_cnt, iface->dhcpv4_router);
 
 
        if (iface->dhcpv4_dns_cnt == 0)
-               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_DNSSERVER, 4, &ifaddr.sin_addr);
+               dhcpv4_put(&reply, &cookie, DHCPV4_OPT_DNSSERVER, 4, ifaddr);
        else
                dhcpv4_put(&reply, &cookie, DHCPV4_OPT_DNSSERVER,
                                4 * iface->dhcpv4_dns_cnt, iface->dhcpv4_dns);
@@ -475,24 +476,21 @@ static void handle_dhcpv4(void *addr, void *data, size_t len,
                ioctl(sock, SIOCSARP, &arp);
        }
 
-       if (dest.sin_addr.s_addr == INADDR_BROADCAST) {
-               /*
-                * reply goes to IP broadcast -> MAC broadcast
-                */
+       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 {
+       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",
+               syslog(LOG_WARNING, "sending %s to %02x:%02x:%02x:%02x:%02x:%02x - %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));
@@ -502,10 +500,11 @@ static bool dhcpv4_test(struct interface *iface, uint32_t try)
 {
        struct dhcpv4_assignment *c;
        list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
-               if (c->addr == try) {
+               if (c->addr == try)
                        return false;
-               }
+
        }
+
        return true;
 }
 
@@ -519,8 +518,7 @@ static bool dhcpv4_assign(struct interface *iface,
        // try to assign the IP the client asked for
        if (start <= raddr && raddr <= end && dhcpv4_test(iface, raddr)) {
                assign->addr = raddr;
-               list_add(&assign->head, &iface->dhcpv4_assignments);
-               syslog(LOG_DEBUG, "assigning the IP the client asked for: %u.%u.%u.%u",
+               syslog(LOG_INFO, "assigning the IP the client asked for: %u.%u.%u.%u",
                                (assign->addr & 0xff000000) >> 24,
                                (assign->addr & 0x00ff0000) >> 16,
                                (assign->addr & 0x0000ff00) >> 8,
@@ -535,14 +533,14 @@ static bool dhcpv4_assign(struct interface *iface,
                uint8_t o = assign->hwaddr[i];
                seed += (o*2654435761) % UINT32_MAX;
        }
+
        srand(seed);
 
        uint32_t try = (((uint32_t)rand()) % count) + start;
 
        if (list_empty(&iface->dhcpv4_assignments)) {
                assign->addr = try;
-               list_add(&assign->head, &iface->dhcpv4_assignments);
-               syslog(LOG_DEBUG, "assigning mapped IP (empty list): %u.%u.%u.%u",
+               syslog(LOG_INFO, "assigning mapped IP (empty list): %u.%u.%u.%u",
                                (assign->addr & 0xff000000) >> 24,
                                (assign->addr & 0x00ff0000) >> 16,
                                (assign->addr & 0x0000ff00) >> 8,
@@ -554,7 +552,6 @@ static bool dhcpv4_assign(struct interface *iface,
                if (dhcpv4_test(iface, try)) {
                        /* test was successful: IP address is not assigned, assign it */
                        assign->addr = try;
-                       list_add(&assign->head, &iface->dhcpv4_assignments);
                        syslog(LOG_DEBUG, "assigning mapped IP: %u.%u.%u.%u (try %u of %u)",
                                        (assign->addr & 0xff000000) >> 24,
                                        (assign->addr & 0x00ff0000) >> 16,
@@ -565,14 +562,14 @@ static bool dhcpv4_assign(struct interface *iface,
                try = (((try - start) + 1) % count) + start;
        }
 
-       syslog(LOG_DEBUG, "can't assign any IP address -> address space is full");
+       syslog(LOG_WARNING, "can't assign any IP address -> address space is full");
        return false;
 }
 
 
 static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface,
                enum dhcpv4_msg msg, const uint8_t *mac, struct in_addr reqaddr,
-               const char *hostname)
+               uint32_t *leasetime, const char *hostname, const size_t hostname_len)
 {
        struct dhcpv4_assignment *lease = NULL;
        uint32_t raddr = ntohl(reqaddr.s_addr);
@@ -584,62 +581,82 @@ static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface,
                        a = c;
                        if (c->addr == raddr)
                                break;
-               } else if (c->valid_until < now) {
-                       list_del(&c->head);
-                       free(c);
-               }
+               } else if (!INFINITE_VALID(c->valid_until) && c->valid_until < now)
+                       free_dhcpv4_assignment(c);
        }
 
        if (msg == DHCPV4_MSG_DISCOVER || msg == DHCPV4_MSG_REQUEST) {
                bool assigned = !!a;
-               size_t hostlen = strlen(hostname) + 1;
+               uint32_t my_leasetime;
 
-               if (!a && !iface->no_dynamic_dhcp) { // Create new binding
-                       a = calloc(1, sizeof(*a) + hostlen);
+               if (!a && !iface->no_dynamic_dhcp) {
+                       /* Create new binding */
+                       a = calloc(1, sizeof(*a));
                        if (!a) {
                                syslog(LOG_ERR, "Failed to calloc binding on interface %s", iface->ifname);
                                return NULL;
                        }
                        memcpy(a->hwaddr, mac, sizeof(a->hwaddr));
-                       memcpy(a->hostname, hostname, hostlen);
+                       /* Don't consider new assignment as infinite */
+                       a->valid_until = now;
 
                        assigned = dhcpv4_assign(iface, a, raddr);
+                       if (assigned)
+                               list_add(&a->head, &iface->dhcpv4_assignments);
                }
 
-               if (assigned && !a->hostname[0] && hostname) {
-                       a = realloc(a, sizeof(*a) + hostlen);
-                       if (!a) {
-                               syslog(LOG_ERR, "Failed to realloc binding on interface %s", iface->ifname);
-                               return NULL;
-                       }
-                       memcpy(a->hostname, hostname, hostlen);
+               if (a->leasetime)
+                       my_leasetime = a->leasetime;
+               else
+                       my_leasetime = iface->dhcpv4_leasetime;
+
+               if ((*leasetime == 0) || (my_leasetime < *leasetime))
+                       *leasetime = my_leasetime;
+
+               if (assigned) {
+                       if (msg == DHCPV4_MSG_DISCOVER) {
+                               a->flags &= ~OAF_BOUND;
+
+                               if (!(a->flags & OAF_STATIC))
+                                       a->valid_until = now;
+                       } else {
+                               if (hostname_len > 0) {
+                                       a->hostname = realloc(a->hostname, hostname_len + 1);
+                                       if (a->hostname) {
+                                               memcpy(a->hostname, hostname, hostname_len);
+                                               a->hostname[hostname_len] = 0;
+                                       }
+                               }
 
-                       // Fixup list
-                       a->head.next->prev = &a->head;
-                       a->head.prev->next = &a->head;
-               }
+                               a->flags |= OAF_BOUND;
 
-               // Was only a solicitation: mark binding for removal
-               if (assigned && a->valid_until < now) {
-                       a->valid_until = (msg == DHCPV4_MSG_DISCOVER) ? 0 :
-                                       (now + iface->dhcpv4_leasetime);
-               } else if (!assigned && a) { // Cleanup failed assignment
-                       free(a);
+                               if (!(a->flags & OAF_STATIC))
+                                       a->valid_until = ((*leasetime == UINT32_MAX) ? 0 : (time_t)(now + *leasetime));
+                       }
+               } else if (!assigned && a) {
+                       /* Cleanup failed assignment */
+                       free_dhcpv4_assignment(a);
                        a = NULL;
                }
 
                if (assigned && a)
                        lease = a;
-       } else if (msg == DHCPV4_MSG_RELEASE) {
-               if (a && a->valid_until != LONG_MAX)
-                       a->valid_until = 0;
-       } else if (msg == DHCPV4_MSG_DECLINE && a && a->valid_until != LONG_MAX) {
-               memset(a->hwaddr, 0, sizeof(a->hwaddr));
-               a->valid_until = now + 3600; // Block address for 1h
+       } else if (msg == DHCPV4_MSG_RELEASE && a) {
+               a->flags &= ~OAF_BOUND;
+
+               if (!(a->flags & OAF_STATIC))
+                       a->valid_until = now - 1;
+
+       } else if (msg == DHCPV4_MSG_DECLINE && a) {
+               a->flags &= ~OAF_BOUND;
+
+               if (!(a->flags & OAF_STATIC)) {
+                       memset(a->hwaddr, 0, sizeof(a->hwaddr));
+                       a->valid_until = now + 3600; /* Block address for 1h */
+               }
        }
 
        dhcpv6_write_statefile();
 
        return lease;
 }
-