X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fodhcpd.git;a=blobdiff_plain;f=src%2Fdhcpv4.c;h=0d7573011dba88379548ac4ab5bcfa223422b516;hp=38b4f9ba5bb9869a19da709897117dc5665e2c37;hb=428908569b8da45613891e21736c587894e0c449;hpb=8b19de666e02f24280728938dd985ecb3673b83e diff --git a/src/dhcpv4.c b/src/dhcpv4.c index 38b4f9b..0d75730 100644 --- a/src/dhcpv4.c +++ b/src/dhcpv4.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -33,12 +34,11 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, - struct interface *iface); + 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); - // Create socket and register events int init_dhcpv4(void) { @@ -49,6 +49,7 @@ int init_dhcpv4(void) int setup_dhcpv4_interface(struct interface *iface, bool enable) { if (iface->dhcpv4_event.uloop.fd > 0) { + uloop_fd_delete(&iface->dhcpv4_event.uloop); close(iface->dhcpv4_event.uloop.fd); iface->dhcpv4_event.uloop.fd = -1; } @@ -58,6 +59,11 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) INIT_LIST_HEAD(&iface->dhcpv4_assignments); 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)); + return -1; + } // Basic IPv6 configuration int val = 1; @@ -65,7 +71,7 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &val, sizeof(val)); setsockopt(sock, IPPROTO_IP, IP_PKTINFO, &val, sizeof(val)); - val = IPTOS_CLASS_CS6; + val = IPTOS_PREC_INTERNETCONTROL; setsockopt(sock, IPPROTO_IP, IP_TOS, &val, sizeof(val)); val = IP_PMTUDISC_DONT; @@ -114,16 +120,22 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) (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) <= 0xffffffc0) { + } 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(20); - iface->dhcpv4_end.s_addr = end | htonl(199); - } else { + 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(59); + 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); } } @@ -136,21 +148,30 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) // Construct entry size_t hostlen = strlen(lease->hostname) + 1; struct dhcpv4_assignment *a = calloc(1, sizeof(*a) + hostlen); - + if (!a) { + syslog(LOG_ERR, "Calloc failed for static lease on interface %s", + iface->ifname); + return -1; + } 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; // 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; } } + if (&c->head == &iface->dhcpv4_assignments) { + list_add(&a->head, &iface->dhcpv4_assignments); + } if (!a->head.next) free(a); @@ -160,7 +181,7 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) 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) != - (saddr->sin_addr.s_addr & smask->sin_addr.s_addr)) { + (iface->dhcpv4_start.s_addr & smask->sin_addr.s_addr)) { list_del(&a->head); free(a); } @@ -168,7 +189,7 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) if (iface->dhcpv4_leasetime < 60) - iface->dhcpv4_leasetime = 1800; + iface->dhcpv4_leasetime = 43200; iface->dhcpv4_event.uloop.fd = sock; iface->dhcpv4_event.handle_dgram = handle_dhcpv4; @@ -204,7 +225,7 @@ static void dhcpv4_put(struct dhcpv4_message *msg, uint8_t **cookie, // Simple DHCPv6-server for information requests static void handle_dhcpv4(void *addr, void *data, size_t len, - struct interface *iface) + struct interface *iface, _unused void *dest_addr) { if (!iface->dhcpv4) return; @@ -284,6 +305,13 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, } else if (opt->type == DHCPV4_OPT_SERVERID && opt->len == 4) { if (memcmp(opt->data, &ifaddr.sin_addr, 4)) return; + } else if (iface->filter_class && opt->type == DHCPV4_OPT_USER_CLASS) { + uint8_t *c = opt->data, *cend = &opt->data[opt->len]; + for (; c < cend && &c[*c] < cend; c = &c[1 + *c]) { + size_t elen = strlen(iface->filter_class); + if (*c == elen && !memcmp(&c[1], iface->filter_class, elen)) + return; // Ignore from homenet + } } } @@ -303,6 +331,19 @@ 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)) { + 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. + * + * 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. + * + */ } if (reqmsg == DHCPV4_MSG_DECLINE || reqmsg == DHCPV4_MSG_RELEASE) @@ -340,14 +381,16 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, dhcpv4_put(&reply, &cookie, DHCPV4_OPT_MTU, 2, &mtu); } - if (iface->search) { - char b[256]; - if (dn_expand(iface->search, iface->search + iface->search_len, - iface->search, b, sizeof(b)) > 0) - dhcpv4_put(&reply, &cookie, DHCPV4_OPT_DOMAIN, strlen(b), b); + 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]) { - dhcpv4_put(&reply, &cookie, DHCPV4_OPT_DOMAIN, - strlen(_res.dnsrch[0]), _res.dnsrch[0]); + uint8_t search_buf[256]; + int len = dn_comp(_res.dnsrch[0], search_buf, + sizeof(search_buf), NULL, NULL); + if (len > 0) + dhcpv4_put(&reply, &cookie, DHCPV4_OPT_SEARCH_DOMAIN, + len, search_buf); } dhcpv4_put(&reply, &cookie, DHCPV4_OPT_ROUTER, 4, &ifaddr.sin_addr); @@ -371,7 +414,7 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, dest.sin_addr = req->ciaddr; dest.sin_port = htons(DHCPV4_CLIENT_PORT); } else if ((ntohs(req->flags) & DHCPV4_FLAG_BROADCAST) || - req->hlen != reply.hlen) { + req->hlen != reply.hlen || !reply.yiaddr.s_addr) { dest.sin_addr.s_addr = INADDR_BROADCAST; dest.sin_port = htons(DHCPV4_CLIENT_PORT); } else { @@ -447,22 +490,26 @@ static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface, struct dhcpv4_assignment *c, *n, *a = NULL; list_for_each_entry_safe(c, n, &iface->dhcpv4_assignments, head) { - if (c->addr == raddr && !memcmp(c->hwaddr, mac, 6)) { + if (!memcmp(c->hwaddr, mac, 6)) { a = c; - break; + if (c->addr == raddr) + break; } else if (c->valid_until < now) { list_del(&c->head); free(c); } } - bool update_state = false; if (msg == DHCPV4_MSG_DISCOVER || msg == DHCPV4_MSG_REQUEST) { bool assigned = !!a; size_t hostlen = strlen(hostname) + 1; if (!a && !iface->no_dynamic_dhcp) { // Create new binding a = calloc(1, sizeof(*a) + hostlen); + 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); @@ -471,6 +518,10 @@ static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface, 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); // Fixup list @@ -492,16 +543,13 @@ static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface, } else if (msg == DHCPV4_MSG_RELEASE) { if (a) { a->valid_until = 0; - update_state = true; } } else if (msg == DHCPV4_MSG_DECLINE) { memset(a->hwaddr, 0, sizeof(a->hwaddr)); a->valid_until = now + 3600; // Block address for 1h - update_state = true; } - if (update_state) - dhcpv6_write_statefile(); + dhcpv6_write_statefile(); return lease; }