X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fodhcpd.git;a=blobdiff_plain;f=src%2Fdhcpv4.c;h=db5f138d95928f05116917d0243f09b997961d1f;hp=21d94f2290330ed291db37f79f76c2792a1f5f14;hb=7aa2594c5a127d92fa8f04328ac7b43e595bcaa7;hpb=a2d8bf66186df66b6e2b645e59c23f8ae2be49c4 diff --git a/src/dhcpv4.c b/src/dhcpv4.c index 21d94f2..db5f138 100644 --- a/src/dhcpv4.c +++ b/src/dhcpv4.c @@ -29,24 +29,47 @@ #include #include +#include + #include "odhcpd.h" #include "dhcpv4.h" #include "dhcpv6.h" +static void dhcpv4_netevent_cb(unsigned long event, struct netevent_handler_info *info); +static int setup_dhcpv4_addresses(struct interface *iface); +static void update_static_assignments(struct interface *iface); +static void valid_until_cb(struct uloop_timeout *event); +static void handle_addrlist_change(struct interface *iface); static void free_dhcpv4_assignment(struct dhcpv4_assignment *a); +static void dhcpv4_fr_start(struct dhcpv4_assignment *a); +static void dhcpv4_fr_stop(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, - uint32_t *leasetime, const char *hostname, const size_t hostname_len); + enum dhcpv4_msg msg, const uint8_t *mac, const uint32_t reqaddr, + uint32_t *leasetime, const char *hostname, const size_t hostname_len, + const bool accept_fr_nonce, bool *incl_fr_opt, uint32_t *fr_serverid); + +static struct netevent_handler dhcpv4_netevent_handler = { .cb = dhcpv4_netevent_cb, }; +static struct uloop_timeout valid_until_timeout = {.cb = valid_until_cb}; +static uint32_t serial = 0; + +struct odhcpd_ref_ip { + struct list_head head; + int ref_cnt; + struct odhcpd_ipaddr addr; +}; /* Create socket and register events */ -int init_dhcpv4(void) +int dhcpv4_init(void) { + uloop_timeout_set(&valid_until_timeout, 1000); + netlink_add_netevent_handler(&dhcpv4_netevent_handler); + return 0; } -int setup_dhcpv4_interface(struct interface *iface, bool enable) +int dhcpv4_setup_interface(struct interface *iface, bool enable) { if (iface->dhcpv4_event.uloop.fd > 0) { uloop_fd_delete(&iface->dhcpv4_event.uloop); @@ -58,10 +81,12 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) if (!iface->dhcpv4_assignments.next) INIT_LIST_HEAD(&iface->dhcpv4_assignments); + if (!iface->dhcpv4_fr_ips.next) + INIT_LIST_HEAD(&iface->dhcpv4_fr_ips); + int sock = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP); if (sock < 0) { - syslog(LOG_ERR, "Failed to create DHCPv4 server socket: %s", - strerror(errno)); + syslog(LOG_ERR, "Failed to create DHCPv4 server socket: %m"); return -1; } @@ -84,124 +109,303 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) {INADDR_ANY}, {0}}; if (bind(sock, (struct sockaddr*)&bind_addr, sizeof(bind_addr))) { - syslog(LOG_ERR, "Failed to open DHCPv4 server socket: %s", - strerror(errno)); + syslog(LOG_ERR, "Failed to open DHCPv4 server socket: %m"); return -1; } + iface->dhcpv4_event.uloop.fd = sock; + iface->dhcpv4_event.handle_dgram = handle_dhcpv4; + odhcpd_register(&iface->dhcpv4_event); - if (ntohl(iface->dhcpv4_start.s_addr) > ntohl(iface->dhcpv4_end.s_addr)) { - syslog(LOG_ERR, "Invalid DHCP range"); + if (setup_dhcpv4_addresses(iface) < 0) return -1; + + update_static_assignments(iface); + } else if (iface->dhcpv4_assignments.next) { + while (!list_empty(&iface->dhcpv4_assignments)) + free_dhcpv4_assignment(list_first_entry(&iface->dhcpv4_assignments, + struct dhcpv4_assignment, head)); + } + return 0; +} + + +static void dhcpv4_netevent_cb(unsigned long event, struct netevent_handler_info *info) +{ + struct interface *iface = info->iface; + + if (!iface || iface->dhcpv4 == MODE_DISABLED) + return; + + switch (event) { + case NETEV_IFINDEX_CHANGE: + dhcpv4_setup_interface(iface, true); + break; + case NETEV_ADDRLIST_CHANGE: + handle_addrlist_change(iface); + break; + default: + break; + } +} + +static struct dhcpv4_assignment *find_assignment_by_hwaddr(struct interface *iface, const uint8_t *hwaddr) +{ + struct dhcpv4_assignment *a; + + list_for_each_entry(a, &iface->dhcpv4_assignments, head) + if (!memcmp(a->hwaddr, hwaddr, 6)) + return a; + + return NULL; +} + +static struct dhcpv4_assignment *find_assignment_by_addr(struct interface *iface, const uint32_t addr) +{ + struct dhcpv4_assignment *a; + + list_for_each_entry(a, &iface->dhcpv4_assignments, head) + if (a->addr == addr) + return a; + + return NULL; +} + +static int setup_dhcpv4_addresses(struct interface *iface) +{ + iface->dhcpv4_start_ip.s_addr = INADDR_ANY; + iface->dhcpv4_end_ip.s_addr = INADDR_ANY; + iface->dhcpv4_local.s_addr = INADDR_ANY; + iface->dhcpv4_bcast.s_addr = INADDR_ANY; + iface->dhcpv4_mask.s_addr = INADDR_ANY; + + /* Sanity checks */ + if (iface->dhcpv4_start.s_addr & htonl(0xffff0000) || + iface->dhcpv4_end.s_addr & htonl(0xffff0000) || + ntohl(iface->dhcpv4_start.s_addr) > ntohl(iface->dhcpv4_end.s_addr)) { + syslog(LOG_ERR, "invalid DHCP range for %s", iface->name); + return -1; + } + + if (!iface->addr4_len) { + syslog(LOG_WARNING, "no network(s) available on %s", iface->name); + return -1; + } + + uint32_t start = ntohl(iface->dhcpv4_start.s_addr); + uint32_t end = ntohl(iface->dhcpv4_end.s_addr); + + for (size_t i = 0; i < iface->addr4_len && start && end; i++) { + struct in_addr *addr = &iface->addr4[i].addr.in; + struct in_addr mask; + + odhcpd_bitlen2netmask(false, iface->addr4[i].prefix, &mask); + if ((start & ntohl(~mask.s_addr)) == start && + (end & ntohl(~mask.s_addr)) == end) { + iface->dhcpv4_start_ip.s_addr = htonl(start) | + (addr->s_addr & mask.s_addr); + iface->dhcpv4_end_ip.s_addr = htonl(end) | + (addr->s_addr & mask.s_addr); + iface->dhcpv4_local = *addr; + iface->dhcpv4_bcast = iface->addr4[i].broadcast; + iface->dhcpv4_mask = mask; + return 0; } + } - /* Create a range if not specified */ - struct ifreq ifreq; - strncpy(ifreq.ifr_name, iface->ifname, sizeof(ifreq.ifr_name)); - - struct sockaddr_in *saddr = (struct sockaddr_in*)&ifreq.ifr_addr; - struct sockaddr_in *smask = (struct sockaddr_in*)&ifreq.ifr_netmask; - if (!(iface->dhcpv4_start.s_addr & htonl(0xffff0000)) && - !(iface->dhcpv4_end.s_addr & htonl(0xffff0000)) && - !ioctl(sock, SIOCGIFADDR, &ifreq)) { - struct in_addr addr = saddr->sin_addr; - - ioctl(sock, SIOCGIFNETMASK, &ifreq); - struct in_addr mask = smask->sin_addr; - - 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) { - iface->dhcpv4_start.s_addr = htonl(start) | - (addr.s_addr & mask.s_addr); - 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; - - if (ntohl(mask.s_addr) <= 0xffffff00) { - iface->dhcpv4_start.s_addr = start | htonl(100); - iface->dhcpv4_end.s_addr = end | htonl(250); - } else if (ntohl(mask.s_addr) <= 0xffffffc0) { - iface->dhcpv4_start.s_addr = start | htonl(10); - iface->dhcpv4_end.s_addr = end | htonl(60); - } else if (ntohl(mask.s_addr) <= 0xffffffe0) { - iface->dhcpv4_start.s_addr = start | htonl(10); - iface->dhcpv4_end.s_addr = end | htonl(30); - } else { - iface->dhcpv4_start.s_addr = start | htonl(3); - iface->dhcpv4_end.s_addr = end | htonl(12); - } - } + /* Don't allocate IP range for subnets bigger than 28 */ + if (iface->addr4[0].prefix > 28) { + syslog(LOG_WARNING, "auto allocation of DHCP range fails on %s", iface->name); + return -1; + } + iface->dhcpv4_local = iface->addr4[0].addr.in; + iface->dhcpv4_bcast = iface->addr4[0].broadcast; + odhcpd_bitlen2netmask(false, iface->addr4[0].prefix, &iface->dhcpv4_mask); + end = start = iface->dhcpv4_local.s_addr & iface->dhcpv4_mask.s_addr; + + /* Auto allocate ranges */ + if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffff00) { + iface->dhcpv4_start_ip.s_addr = start | htonl(100); + iface->dhcpv4_end_ip.s_addr = end | htonl(250); + } else if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffffc0) { + iface->dhcpv4_start_ip.s_addr = start | htonl(10); + iface->dhcpv4_end_ip.s_addr = end | htonl(60); + } else if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffffe0) { + iface->dhcpv4_start_ip.s_addr = start | htonl(10); + iface->dhcpv4_end_ip.s_addr = end | htonl(30); + } else { + iface->dhcpv4_start_ip.s_addr = start | htonl(3); + iface->dhcpv4_end_ip.s_addr = end | htonl(12); + } + return 0; +} + +static void update_static_assignments(struct interface *iface) +{ + struct dhcpv4_assignment *a, *c; + + /* Cleanup static entries not belonging to the network */ + list_for_each_entry_safe(a, c, &iface->dhcpv4_assignments, head) { + if ((a->flags & OAF_STATIC) && + ((a->addr & iface->dhcpv4_mask.s_addr) != + (iface->dhcpv4_start.s_addr & iface->dhcpv4_mask.s_addr))) + free_dhcpv4_assignment(a); + } + + /* Parse static entries */ + struct lease *lease; + list_for_each_entry(lease, &leases, head) { + if ((iface->dhcpv4_start_ip.s_addr & iface->dhcpv4_mask.s_addr) != + (lease->ipaddr.s_addr & iface->dhcpv4_mask.s_addr)) { + continue; } - /* Parse static entries */ - struct lease *lease; - list_for_each_entry(lease, &leases, head) { + a = find_assignment_by_hwaddr(iface, lease->mac.ether_addr_octet); + + if (!a) { + /* Check if there's an assignment with the specified IP address */ + if (find_assignment_by_addr(iface, lease->ipaddr.s_addr)) + continue; + /* Construct entry */ - struct dhcpv4_assignment *a = calloc(1, sizeof(*a)); + a = calloc(1, sizeof(*a)); if (!a) { syslog(LOG_ERR, "Calloc failed for static lease on interface %s", iface->ifname); - return -1; + continue; } + memcpy(a->hwaddr, lease->mac.ether_addr_octet, sizeof(a->hwaddr)); + } - a->leasetime = lease->dhcpv4_leasetime; + a->leasetime = lease->dhcpv4_leasetime; + + a->addr = lease->ipaddr.s_addr; + /* Static assignment */ + a->flags |= OAF_STATIC; + /* Infinite valid */ + a->valid_until = 0; + a->iface = iface; + if (lease->hostname[0]) { + free(a->hostname); + a->hostname = strdup(lease->hostname); + } - a->addr = ntohl(lease->ipaddr.s_addr); - memcpy(a->hwaddr, lease->mac.ether_addr_octet, sizeof(a->hwaddr)); - /* Static assignment */ - a->flags |= OAF_STATIC; - /* Infinite valid */ - a->valid_until = 0; - - /* 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 */ - break; + /* Assign to all interfaces */ + list_for_each_entry(c, &iface->dhcpv4_assignments, head) { + if (ntohl(c->addr) > ntohl(a->addr)) { + list_add_tail(&a->head, &c->head); + break; } + } - if (&c->head == &iface->dhcpv4_assignments) - list_add(&a->head, &iface->dhcpv4_assignments); + if (&c->head == &iface->dhcpv4_assignments) + list_add(&a->head, &iface->dhcpv4_assignments); + } +} - if (a->head.next) { - if (lease->hostname[0]) { - free(a->hostname); - a->hostname = strdup(lease->hostname); - } - } else - free_dhcpv4_assignment(a); +static void inc_ref_cnt_ip(struct odhcpd_ref_ip **ptr, struct odhcpd_ref_ip *ip) +{ + *ptr = ip; + ip->ref_cnt++; +} + +static void decr_ref_cnt_ip(struct odhcpd_ref_ip **ptr, struct interface *iface) +{ + struct odhcpd_ref_ip *ip = *ptr; + + if (--ip->ref_cnt == 0) { + netlink_setup_addr(&ip->addr, iface->ifindex, false, false); + + list_del(&ip->head); + free(ip); + } + + *ptr = NULL; +} + +static bool leases_require_fr(struct interface *iface, struct odhcpd_ipaddr *addr, + uint32_t mask) +{ + struct dhcpv4_assignment *a = NULL; + struct odhcpd_ref_ip *fr_ip = NULL; + + list_for_each_entry(a, &iface->dhcpv4_assignments, head) { + if ((a->accept_fr_nonce || iface->dhcpv4_forcereconf) && + !a->fr_ip && + ((a->addr & mask) == (addr->addr.in.s_addr & mask))) { + if (!fr_ip) { + fr_ip = calloc(1, sizeof(*fr_ip)); + if (!fr_ip) + break; + + list_add(&fr_ip->head, &iface->dhcpv4_fr_ips); + fr_ip->addr = *addr; + } + inc_ref_cnt_ip(&a->fr_ip, fr_ip); } + } + + return fr_ip ? true : false; +} + +static void valid_until_cb(struct uloop_timeout *event) +{ + time_t now = odhcpd_time(); + struct interface *iface; + list_for_each_entry(iface, &interfaces, head) { + if (iface->dhcpv4 != MODE_SERVER || iface->dhcpv4_assignments.next == NULL) + continue; - // Clean invalid assignments struct dhcpv4_assignment *a, *n; list_for_each_entry_safe(a, n, &iface->dhcpv4_assignments, head) { - if ((htonl(a->addr) & smask->sin_addr.s_addr) != - (iface->dhcpv4_start.s_addr & smask->sin_addr.s_addr)) + if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) free_dhcpv4_assignment(a); } + } + uloop_timeout_set(event, 1000); +} - 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)) - free_dhcpv4_assignment(list_first_entry(&iface->dhcpv4_assignments, - struct dhcpv4_assignment, head)); +static void handle_addrlist_change(struct interface *iface) +{ + struct odhcpd_ipaddr ip; + struct odhcpd_ref_ip *a; + struct dhcpv4_assignment *c; + uint32_t mask = iface->dhcpv4_mask.s_addr; + + memset(&ip, 0, sizeof(ip)); + ip.addr.in = iface->dhcpv4_local; + ip.prefix = odhcpd_netmask2bitlen(false, &iface->dhcpv4_mask); + ip.broadcast = iface->dhcpv4_bcast; + + setup_dhcpv4_addresses(iface); + + if ((ip.addr.in.s_addr & mask) == + (iface->dhcpv4_local.s_addr & iface->dhcpv4_mask.s_addr)) + return; + + if (ip.addr.in.s_addr && !leases_require_fr(iface, &ip, mask)) + return; + + if (iface->dhcpv4_local.s_addr == INADDR_ANY || list_empty(&iface->dhcpv4_fr_ips)) + return; + + a = list_first_entry(&iface->dhcpv4_fr_ips, struct odhcpd_ref_ip, head); + + if (netlink_setup_addr(&a->addr, iface->ifindex, false, true)) { + syslog(LOG_ERR, "Failed to add ip address"); + return; + } + + list_for_each_entry(c, &iface->dhcpv4_assignments, head) { + if ((c->flags & OAF_BOUND) && c->fr_ip && !c->fr_cnt) { + if (c->accept_fr_nonce || iface->dhcpv4_forcereconf) + dhcpv4_fr_start(c); + else + dhcpv4_fr_stop(c); + } } - return 0; } static char *dhcpv4_msg_to_string(uint8_t reqmsg) @@ -223,6 +427,8 @@ static char *dhcpv4_msg_to_string(uint8_t reqmsg) return "DHCPV4_MSG_RELEASE"; case (DHCPV4_MSG_INFORM): return "DHCPV4_MSG_INFORM"; + case (DHCPV4_MSG_FORCERENEW): + return "DHCPV4_MSG_FORCERENEW"; default: return "UNKNOWN"; } @@ -233,6 +439,9 @@ static void free_dhcpv4_assignment(struct dhcpv4_assignment *a) if (a->head.next) list_del(&a->head); + if (a->fr_ip) + dhcpv4_fr_stop(a); + free(a->hostname); free(a); } @@ -251,6 +460,123 @@ static void dhcpv4_put(struct dhcpv4_message *msg, uint8_t **cookie, *cookie = c + len; } +static void dhcpv4_fr_send(struct dhcpv4_assignment *a) +{ + struct dhcpv4_message fr_msg = { + .op = DHCPV4_BOOTREPLY, + .htype = 1, + .hlen = 6, + .hops = 0, + .secs = 0, + .flags = 0, + .ciaddr = {INADDR_ANY}, + .yiaddr = {INADDR_ANY}, + .siaddr = {INADDR_ANY}, + .giaddr = {INADDR_ANY}, + .chaddr = {0}, + .sname = {0}, + .file = {0}, + }; + struct dhcpv4_auth_forcerenew *auth_o, auth = { + .protocol = 3, + .algorithm = 1, + .rdm = 0, + .replay = {htonl(time(NULL)), htonl(++serial)}, + .type = 2, + .key = {0}, + }; + struct interface *iface = a->iface; + + odhcpd_urandom(&fr_msg.xid, sizeof(fr_msg.xid)); + memcpy(fr_msg.chaddr, a->hwaddr, fr_msg.hlen); + + fr_msg.options[0] = 0x63; + fr_msg.options[1] = 0x82; + fr_msg.options[2] = 0x53; + fr_msg.options[3] = 0x63; + + uint8_t *cookie = &fr_msg.options[4]; + uint8_t msg = DHCPV4_MSG_FORCERENEW; + + dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_MESSAGE, 1, &msg); + if (a->accept_fr_nonce) { + dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_AUTHENTICATION, sizeof(auth), &auth); + auth_o = (struct dhcpv4_auth_forcerenew *)(cookie - sizeof(auth)); + dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_END, 0, NULL); + + md5_ctx_t md5; + uint8_t secretbytes[64]; + memset(secretbytes, 0, sizeof(secretbytes)); + memcpy(secretbytes, a->key, sizeof(a->key)); + + for (size_t i = 0; i < sizeof(secretbytes); ++i) + secretbytes[i] ^= 0x36; + + md5_begin(&md5); + md5_hash(secretbytes, sizeof(secretbytes), &md5); + md5_hash(&fr_msg, sizeof(fr_msg), &md5); + md5_end(auth_o->key, &md5); + + for (size_t i = 0; i < sizeof(secretbytes); ++i) { + secretbytes[i] ^= 0x36; + secretbytes[i] ^= 0x5c; + } + + md5_begin(&md5); + md5_hash(secretbytes, sizeof(secretbytes), &md5); + md5_hash(auth_o->key, sizeof(auth_o->key), &md5); + md5_end(auth_o->key, &md5); + } else { + dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_SERVERID, 4, + &a->fr_ip->addr.addr.in.s_addr); + dhcpv4_put(&fr_msg, &cookie, DHCPV4_OPT_END, 0, NULL); + } + + struct sockaddr_in dest; + memset(&dest, 0, sizeof(dest)); + dest.sin_family = AF_INET; + dest.sin_port = htons(DHCPV4_CLIENT_PORT); + dest.sin_addr.s_addr = a->addr; + + syslog(LOG_WARNING, "sending %s to %02x:%02x:%02x:%02x:%02x:%02x - %s", + dhcpv4_msg_to_string(msg), + a->hwaddr[0], a->hwaddr[1], a->hwaddr[2], + a->hwaddr[3], a->hwaddr[4], a->hwaddr[5], + inet_ntoa(dest.sin_addr)); + + sendto(iface->dhcpv4_event.uloop.fd, &fr_msg, sizeof(fr_msg), + MSG_DONTWAIT, (struct sockaddr*)&dest, sizeof(dest)); +} + +static void dhcpv4_fr_timer(struct uloop_timeout *event) +{ + struct dhcpv4_assignment *a = container_of(event, struct dhcpv4_assignment, fr_timer); + + if (a->fr_cnt > 0 && a->fr_cnt < 8) { + dhcpv4_fr_send(a); + uloop_timeout_set(&a->fr_timer, 1000 << a->fr_cnt); + a->fr_cnt++; + } else + dhcpv4_fr_stop(a); +} + +static void dhcpv4_fr_start(struct dhcpv4_assignment *a) +{ + uloop_timeout_set(&a->fr_timer, 1000 << a->fr_cnt); + a->fr_timer.cb = dhcpv4_fr_timer; + a->fr_cnt++; + + dhcpv4_fr_send(a); +} + +static void dhcpv4_fr_stop(struct dhcpv4_assignment *a) +{ + uloop_timeout_cancel(&a->fr_timer); + decr_ref_cnt_ip(&a->fr_ip, a->iface); + a->fr_cnt = 0; + a->fr_timer.cb = NULL; +} + // Handler for DHCPv4 messages static void handle_dhcpv4(void *addr, void *data, size_t len, struct interface *iface, _unused void *dest_addr) @@ -263,46 +589,27 @@ 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->dhcpv4_start_ip.s_addr && !iface->dhcpv4_end_ip.s_addr) { + syslog(LOG_WARNING, "No DHCP range available 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; - - if ((iface->dhcpv4_start.s_addr & ifnetmask.sin_addr.s_addr) != network || - (iface->dhcpv4_end.s_addr & ifnetmask.sin_addr.s_addr) != 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)); + int sock = iface->dhcpv4_event.uloop.fd; struct dhcpv4_message reply = { .op = DHCPV4_BOOTREPLY, - .htype = 1, - .hlen = 6, + .htype = req->htype, + .hlen = req->hlen, .hops = 0, .xid = req->xid, .secs = 0, .flags = req->flags, .ciaddr = {INADDR_ANY}, .giaddr = req->giaddr, - .siaddr = ifaddr.sin_addr, + .siaddr = iface->dhcpv4_local, }; memcpy(reply.chaddr, req->chaddr, sizeof(reply.chaddr)); @@ -315,10 +622,12 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, uint8_t reqmsg = DHCPV4_MSG_REQUEST; uint8_t msg = DHCPV4_MSG_ACK; - struct in_addr reqaddr = {INADDR_ANY}; + uint32_t reqaddr = INADDR_ANY; uint32_t leasetime = 0; size_t hostname_len = 0; char hostname[256]; + bool accept_fr_nonce = false; + bool incl_fr_opt = false; uint8_t *start = &req->options[4]; uint8_t *end = ((uint8_t*)data) + len; @@ -333,7 +642,7 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, } 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)) + if (memcmp(opt->data, &iface->dhcpv4_local, 4)) return; } else if (iface->filter_class && opt->type == DHCPV4_OPT_USER_CLASS) { uint8_t *c = opt->data, *cend = &opt->data[opt->len]; @@ -344,6 +653,15 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, } } else if (opt->type == DHCPV4_OPT_LEASETIME && opt->len == 4) memcpy(&leasetime, opt->data, 4); + else if (opt->type == DHCPV4_OPT_FORCERENEW_NONCE_CAPABLE && opt->len > 0) { + for (uint8_t i = 0; i < opt->len; i++) { + if (opt->data[i] == 1) { + accept_fr_nonce = true; + break; + } + } + + } } if (reqmsg != DHCPV4_MSG_DISCOVER && reqmsg != DHCPV4_MSG_REQUEST && @@ -352,9 +670,13 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, return; struct dhcpv4_assignment *lease = NULL; + uint32_t serverid = iface->dhcpv4_local.s_addr; + uint32_t fr_serverid = INADDR_ANY; + if (reqmsg != DHCPV4_MSG_INFORM) lease = dhcpv4_lease(iface, reqmsg, req->chaddr, reqaddr, - &leasetime, hostname, hostname_len); + &leasetime, hostname, hostname_len, + accept_fr_nonce, &incl_fr_opt, &fr_serverid); if (!lease) { if (reqmsg == DHCPV4_MSG_REQUEST) @@ -363,19 +685,35 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, return; } else if (reqmsg == DHCPV4_MSG_DISCOVER) msg = DHCPV4_MSG_OFFER; - else if (reqmsg == DHCPV4_MSG_REQUEST && reqaddr.s_addr && - reqaddr.s_addr != htonl(lease->addr)) { + else if (reqmsg == DHCPV4_MSG_REQUEST && + ((reqaddr && reqaddr != lease->addr) || + (req->ciaddr.s_addr && req->ciaddr.s_addr != lease->addr))) { msg = DHCPV4_MSG_NAK; /* * DHCP client requested an IP which we can't offer to him. Probably the - * client changed the network. The reply type is set to DHCPV4_MSG_NAK, - * because the client should not use that IP. + * client changed the network or the network has been changed. The reply + * type is set to DHCPV4_MSG_NAK, because the client should not use that IP. * * For modern devices we build an answer that includes a valid IP, like * a DHCPV4_MSG_ACK. The client will use that IP and doesn't need to * perform additional DHCP round trips. * */ + + /* + * + * Buggy clients do serverid checking in nack messages; therefore set the + * serverid in nack messages triggered by a previous force renew equal to + * the server id in use at that time by the server + * + */ + if (fr_serverid) + serverid = fr_serverid; + + if (req->ciaddr.s_addr && + ((iface->dhcpv4_start_ip.s_addr & iface->dhcpv4_mask.s_addr) != + (req->ciaddr.s_addr & iface->dhcpv4_mask.s_addr))) + req->ciaddr.s_addr = INADDR_ANY; } syslog(LOG_WARNING, "received %s from %02x:%02x:%02x:%02x:%02x:%02x", @@ -383,16 +721,21 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, req->chaddr[0],req->chaddr[1],req->chaddr[2], req->chaddr[3],req->chaddr[4],req->chaddr[5]); +#ifdef WITH_UBUS + if (reqmsg == DHCPV4_MSG_RELEASE) + ubus_bcast_dhcp_event("dhcp.release", req->chaddr, req->hlen, + &req->ciaddr, hostname, iface->ifname); +#endif if (reqmsg == DHCPV4_MSG_DECLINE || reqmsg == DHCPV4_MSG_RELEASE) 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, &serverid); if (lease) { uint32_t val; - reply.yiaddr.s_addr = htonl(lease->addr); + reply.yiaddr.s_addr = lease->addr; val = htonl(leasetime); dhcpv4_put(&reply, &cookie, DHCPV4_OPT_LEASETIME, 4, &val); @@ -405,18 +748,40 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, 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, + &iface->dhcpv4_mask.s_addr); 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 (iface->dhcpv4_bcast.s_addr != INADDR_ANY) + dhcpv4_put(&reply, &cookie, DHCPV4_OPT_BROADCAST, 4, &iface->dhcpv4_bcast); + + if (incl_fr_opt) { + if (reqmsg == DHCPV4_MSG_REQUEST) { + struct dhcpv4_auth_forcerenew auth = { + .protocol = 3, + .algorithm = 1, + .rdm = 0, + .replay = {htonl(time(NULL)), htonl(++serial)}, + .type = 1, + .key = {0}, + }; + + memcpy(auth.key, lease->key, sizeof(auth.key)); + dhcpv4_put(&reply, &cookie, DHCPV4_OPT_AUTHENTICATION, sizeof(auth), &auth); + } else { + uint8_t one = 1; + dhcpv4_put(&reply, &cookie, DHCPV4_OPT_FORCERENEW_NONCE_CAPABLE, + sizeof(one), &one); + } } } + 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); @@ -435,14 +800,14 @@ 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, &iface->dhcpv4_local); 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, &iface->dhcpv4_local); else dhcpv4_put(&reply, &cookie, DHCPV4_OPT_DNSSERVER, 4 * iface->dhcpv4_dns_cnt, iface->dhcpv4_dns); @@ -510,36 +875,30 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, sendto(sock, &reply, sizeof(reply), MSG_DONTWAIT, (struct sockaddr*)&dest, sizeof(dest)); -} - -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) - return false; - } - - return true; +#ifdef WITH_UBUS + if (msg == DHCPV4_MSG_ACK) + ubus_bcast_dhcp_event("dhcp.ack", req->chaddr, req->hlen, &reply.yiaddr, + hostname, iface->ifname); +#endif } static bool dhcpv4_assign(struct interface *iface, struct dhcpv4_assignment *assign, uint32_t raddr) { - uint32_t start = ntohl(iface->dhcpv4_start.s_addr); - uint32_t end = ntohl(iface->dhcpv4_end.s_addr); + uint32_t start = ntohl(iface->dhcpv4_start_ip.s_addr); + uint32_t end = ntohl(iface->dhcpv4_end_ip.s_addr); uint32_t count = end - start + 1; // try to assign the IP the client asked for - if (start <= raddr && raddr <= end && dhcpv4_test(iface, raddr)) { + if (start <= ntohl(raddr) && ntohl(raddr) <= end && + !find_assignment_by_addr(iface, raddr)) { assign->addr = raddr; - list_add(&assign->head, &iface->dhcpv4_assignments); 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, - (assign->addr & 0x000000ff)); + ((uint8_t *)&assign->addr)[0], + ((uint8_t *)&assign->addr)[1], + ((uint8_t *)&assign->addr)[2], + ((uint8_t *)&assign->addr)[3]); return true; } @@ -556,26 +915,25 @@ static bool dhcpv4_assign(struct interface *iface, uint32_t try = (((uint32_t)rand()) % count) + start; if (list_empty(&iface->dhcpv4_assignments)) { - assign->addr = try; - list_add(&assign->head, &iface->dhcpv4_assignments); + assign->addr = htonl(try); syslog(LOG_INFO, "assigning mapped IP (empty list): %u.%u.%u.%u", - (assign->addr & 0xff000000) >> 24, - (assign->addr & 0x00ff0000) >> 16, - (assign->addr & 0x0000ff00) >> 8, - (assign->addr & 0x000000ff)); + ((uint8_t *)&assign->addr)[0], + ((uint8_t *)&assign->addr)[1], + ((uint8_t *)&assign->addr)[2], + ((uint8_t *)&assign->addr)[3]); return true; } for (uint32_t i = 0; i < count; ++i) { - if (dhcpv4_test(iface, try)) { + if (!find_assignment_by_addr(iface, htonl(try))) { /* test was successful: IP address is not assigned, assign it */ - assign->addr = try; - list_add(&assign->head, &iface->dhcpv4_assignments); + assign->addr = htonl(try); syslog(LOG_DEBUG, "assigning mapped IP: %u.%u.%u.%u (try %u of %u)", - (assign->addr & 0xff000000) >> 24, - (assign->addr & 0x00ff0000) >> 16, - (assign->addr & 0x0000ff00) >> 8, - (assign->addr & 0x000000ff), i, count); + ((uint8_t *)&assign->addr)[0], + ((uint8_t *)&assign->addr)[1], + ((uint8_t *)&assign->addr)[2], + ((uint8_t *)&assign->addr)[3], + i, count); return true; } try = (((try - start) + 1) % count) + start; @@ -587,53 +945,65 @@ static bool dhcpv4_assign(struct interface *iface, static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface, - enum dhcpv4_msg msg, const uint8_t *mac, struct in_addr reqaddr, - uint32_t *leasetime, const char *hostname, const size_t hostname_len) + enum dhcpv4_msg msg, const uint8_t *mac, const uint32_t reqaddr, + uint32_t *leasetime, const char *hostname, const size_t hostname_len, + const bool accept_fr_nonce, bool *incl_fr_opt, uint32_t *fr_serverid) { + struct dhcpv4_assignment *a = find_assignment_by_hwaddr(iface, mac); struct dhcpv4_assignment *lease = NULL; - uint32_t raddr = ntohl(reqaddr.s_addr); time_t now = odhcpd_time(); - struct dhcpv4_assignment *c, *n, *a = NULL; - list_for_each_entry_safe(c, n, &iface->dhcpv4_assignments, head) { - if (!memcmp(c->hwaddr, mac, 6)) { - a = c; - if (c->addr == raddr) - break; - } else if (!INFINITE_VALID(c->valid_until) && c->valid_until < now) - free_dhcpv4_assignment(c); + if (a && (a->flags & OAF_BOUND) && a->fr_ip) { + *fr_serverid = a->fr_ip->addr.addr.in.s_addr; + dhcpv4_fr_stop(a); } if (msg == DHCPV4_MSG_DISCOVER || msg == DHCPV4_MSG_REQUEST) { bool assigned = !!a; - uint32_t my_leasetime; - 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; + if (!a) { + if (!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)); + /* Don't consider new assignment as infinite */ + a->valid_until = now; + + assigned = dhcpv4_assign(iface, a, reqaddr); + if (assigned) { + a->iface = iface; + list_add(&a->head, &iface->dhcpv4_assignments); + } } - memcpy(a->hwaddr, mac, sizeof(a->hwaddr)); - /* Don't consider new assignment as infinite */ - a->valid_until = now; + } else if ((a->addr & iface->dhcpv4_mask.s_addr) != + (iface->dhcpv4_start_ip.s_addr & iface->dhcpv4_mask.s_addr)) { + list_del(&a->head); - assigned = dhcpv4_assign(iface, a, raddr); + assigned = dhcpv4_assign(iface, a, reqaddr); + if (assigned) + list_add(&a->head, &iface->dhcpv4_assignments); } - if (a->leasetime) - my_leasetime = a->leasetime; - else - my_leasetime = iface->dhcpv4_leasetime; + if (assigned) { + uint32_t my_leasetime; - if ((*leasetime == 0) || (my_leasetime < *leasetime)) - *leasetime = my_leasetime; + 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; + *incl_fr_opt = accept_fr_nonce; if (!(a->flags & OAF_STATIC)) a->valid_until = now; } else { @@ -645,7 +1015,13 @@ static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface, } } - a->flags |= OAF_BOUND; + if (!(a->flags & OAF_BOUND)) { + a->accept_fr_nonce = accept_fr_nonce; + *incl_fr_opt = accept_fr_nonce; + odhcpd_urandom(a->key, sizeof(a->key)); + a->flags |= OAF_BOUND; + } else + *incl_fr_opt = false; if (!(a->flags & OAF_STATIC)) a->valid_until = ((*leasetime == UINT32_MAX) ? 0 : (time_t)(now + *leasetime));