#include <unistd.h>
#include <signal.h>
#include <stdbool.h>
+#include <syslog.h>
+#include <alloca.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <netinet/ip6.h>
#include <netpacket/packet.h>
+#include <linux/netlink.h>
+#include <linux/if_addr.h>
+#include <linux/neighbour.h>
#include <linux/rtnetlink.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sys/syscall.h>
+#include <netlink/msg.h>
+#include <netlink/socket.h>
+#include <netlink/attr.h>
#include <libubox/uloop.h>
#include "odhcpd.h"
static int ioctl_sock;
-static int rtnl_socket = -1;
-static int rtnl_seq = 0;
+static struct nl_sock *rtnl_socket = NULL;
static int urandom_fd = -1;
-
static void sighandler(_unused int signal)
{
uloop_end();
}
+static void print_usage(const char *app)
+{
+ printf(
+ "== %s Usage ==\n\n"
+ " -h, --help Print this help\n"
+ " -l level Specify log level 0..7 (default %d)\n",
+ app, config.log_level
+ );
+}
-int main()
+int main(int argc, char **argv)
{
openlog("odhcpd", LOG_PERROR | LOG_PID, LOG_DAEMON);
- setlogmask(LOG_UPTO(LOG_WARNING));
+ int opt;
+
+ while ((opt = getopt(argc, argv, "hl:")) != -1) {
+ switch (opt) {
+ case 'h':
+ print_usage(argv[0]);
+ return 0;
+ case 'l':
+ config.log_level = (atoi(optarg) & LOG_PRIMASK);
+ fprintf(stderr, "Log level set to %d\n", config.log_level);
+ break;
+ }
+ }
+ setlogmask(LOG_UPTO(config.log_level));
uloop_init();
if (getuid() != 0) {
ioctl_sock = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
- if ((rtnl_socket = odhcpd_open_rtnl()) < 0) {
- syslog(LOG_ERR, "Unable to open socket: %s", strerror(errno));
+ if (!(rtnl_socket = odhcpd_create_nl_socket(NETLINK_ROUTE))) {
+ syslog(LOG_ERR, "Unable to open nl socket: %s", strerror(errno));
return 2;
}
return 0;
}
-int odhcpd_open_rtnl(void)
+struct nl_sock *odhcpd_create_nl_socket(int protocol)
{
- int sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);
+ struct nl_sock *nl_sock;
- // Connect to the kernel netlink interface
- struct sockaddr_nl nl = {.nl_family = AF_NETLINK};
- if (connect(sock, (struct sockaddr*)&nl, sizeof(nl))) {
- syslog(LOG_ERR, "Failed to connect to kernel rtnetlink: %s",
- strerror(errno));
- return -1;
- }
+ nl_sock = nl_socket_alloc();
+ if (!nl_sock)
+ goto err;
+
+ if (nl_connect(nl_sock, protocol) < 0)
+ goto err;
- return sock;
+ return nl_sock;
+
+err:
+ if (nl_sock)
+ nl_socket_free(nl_sock);
+
+ return NULL;
}
|| IN6_IS_ADDR_MC_LINKLOCAL(&dest->sin6_addr))
dest->sin6_scope_id = iface->ifindex;
- // IPV6_PKTINFO doesn't really work for IPv6-raw sockets (bug?)
- if (dest->sin6_port == 0) {
- msg.msg_control = NULL;
- msg.msg_controllen = 0;
- }
-
char ipbuf[INET6_ADDRSTRLEN];
inet_ntop(AF_INET6, &dest->sin6_addr, ipbuf, sizeof(ipbuf));
return sent;
}
+struct addr_info {
+ int ifindex;
+ int af;
+ struct odhcpd_ipaddr **addrs;
+ int pending;
+ ssize_t ret;
+};
-int odhcpd_iterate_interface_neighbors(const struct interface *iface,
- void(*cb_neigh)(const struct in6_addr *addr,
- const struct interface *iface, void *data), void *data)
+static int cb_valid_handler(struct nl_msg *msg, void *arg)
{
- struct {
- struct nlmsghdr nhm;
- struct ndmsg ndm;
- } req = {{sizeof(req), RTM_GETNEIGH, NLM_F_REQUEST | NLM_F_DUMP,
- ++rtnl_seq, 0}, {AF_INET6, 0, 0, iface->ifindex, 0, 0, 0}};
-
- if (send(rtnl_socket, &req, sizeof(req), 0) < (ssize_t)sizeof(req))
- return -1;
+ struct addr_info *ctxt = (struct addr_info *)arg;
+ struct odhcpd_ipaddr *addrs = *(ctxt->addrs);
+ struct nlmsghdr *hdr = nlmsg_hdr(msg);
+ struct ifaddrmsg *ifa;
+ struct nlattr *nla[__IFA_MAX], *nla_addr = NULL;
+
+ if (hdr->nlmsg_type != RTM_NEWADDR)
+ return NL_SKIP;
+
+ ifa = NLMSG_DATA(hdr);
+ if (ifa->ifa_scope != RT_SCOPE_UNIVERSE ||
+ (ctxt->af != ifa->ifa_family) ||
+ (ctxt->ifindex && ifa->ifa_index != (unsigned)ctxt->ifindex))
+ return NL_SKIP;
+
+ nlmsg_parse(hdr, sizeof(*ifa), nla, __IFA_MAX - 1, NULL);
+
+ switch (ifa->ifa_family) {
+ case AF_INET6:
+ if (nla[IFA_ADDRESS])
+ nla_addr = nla[IFA_ADDRESS];
+ break;
+
+ case AF_INET:
+ if (nla[IFA_LOCAL])
+ nla_addr = nla[IFA_LOCAL];
+ break;
+
+ default:
+ break;
+ }
+ if (!nla_addr)
+ return NL_SKIP;
- uint8_t buf[8192];
- ssize_t len = 0;
-
- for (struct nlmsghdr *nhm = NULL; ; nhm = NLMSG_NEXT(nhm, len)) {
- while (len < 0 || !NLMSG_OK(nhm, (size_t)len)) {
- len = recv(rtnl_socket, buf, sizeof(buf), 0);
- nhm = (struct nlmsghdr*)buf;
- if (len < 0 || !NLMSG_OK(nhm, (size_t)len)) {
- if (errno == EINTR)
- continue;
- else
- return -1;
- }
- }
+ addrs = realloc(addrs, sizeof(*addrs)*(ctxt->ret + 1));
+ if (!addrs)
+ return NL_SKIP;
- if (nhm->nlmsg_type != RTM_NEWNEIGH)
- break;
+ memset(&addrs[ctxt->ret], 0, sizeof(addrs[ctxt->ret]));
+ addrs[ctxt->ret].prefix = ifa->ifa_prefixlen;
- struct ndmsg *ndm = NLMSG_DATA(nhm);
- if (ndm->ndm_ifindex != iface->ifindex ||
- (ndm->ndm_state & NUD_FAILED))
- continue;
+ nla_memcpy(&addrs[ctxt->ret].addr, nla_addr,
+ sizeof(addrs[ctxt->ret].addr));
- struct rtattr *rta = (struct rtattr*)&ndm[1];
- size_t alen = NLMSG_PAYLOAD(nhm, sizeof(*ndm));
+ if (nla[IFA_BROADCAST])
+ nla_memcpy(&addrs[ctxt->ret].broadcast, nla[IFA_BROADCAST],
+ sizeof(addrs[ctxt->ret].broadcast));
- while (RTA_OK(rta, alen)) {
- if (rta->rta_type == NDA_DST &&
- RTA_PAYLOAD(rta) == sizeof(struct in6_addr)) {
- cb_neigh(RTA_DATA(rta), iface, data);
- break;
- } else {
- rta = RTA_NEXT(rta, alen);
- }
- }
+ if (nla[IFA_CACHEINFO]) {
+ struct ifa_cacheinfo *ifc = nla_data(nla[IFA_CACHEINFO]);
+ addrs[ctxt->ret].preferred = ifc->ifa_prefered;
+ addrs[ctxt->ret].valid = ifc->ifa_valid;
}
- return 0;
+ if (ifa->ifa_flags & IFA_F_DEPRECATED)
+ addrs[ctxt->ret].preferred = 0;
+
+ ctxt->ret++;
+ *(ctxt->addrs) = addrs;
+
+ return NL_OK;
+}
+
+static int cb_finish_handler(_unused struct nl_msg *msg, void *arg)
+{
+ struct addr_info *ctxt = (struct addr_info *)arg;
+
+ ctxt->pending = 0;
+
+ return NL_STOP;
+}
+
+static int cb_error_handler(_unused struct sockaddr_nl *nla, struct nlmsgerr *err,
+ void *arg)
+{
+ struct addr_info *ctxt = (struct addr_info *)arg;
+
+ ctxt->pending = 0;
+ ctxt->ret = err->error;
+
+ return NL_STOP;
+}
+
+static int prefix_cmp(const void *va, const void *vb)
+{
+ const struct odhcpd_ipaddr *a = va, *b = vb;
+ int ret = 0;
+
+ if (a->prefix == b->prefix) {
+ ret = (ntohl(a->addr.in.s_addr) < ntohl(b->addr.in.s_addr)) ? 1 :
+ (ntohl(a->addr.in.s_addr) > ntohl(b->addr.in.s_addr)) ? -1 : 0;
+ } else
+ ret = a->prefix < b->prefix ? 1 : -1;
+
+ return ret;
}
+// compare IPv6 prefixes
+static int prefix6_cmp(const void *va, const void *vb)
+{
+ const struct odhcpd_ipaddr *a = va, *b = vb;
+ uint32_t a_pref = IN6_IS_ADDR_ULA(&a->addr.in6) ? 1 : a->preferred;
+ uint32_t b_pref = IN6_IS_ADDR_ULA(&b->addr.in6) ? 1 : b->preferred;
+ return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
+}
// Detect an IPV6-address currently assigned to the given interface
-ssize_t odhcpd_get_interface_addresses(int ifindex,
- struct odhcpd_ipaddr *addrs, size_t cnt)
-{
- struct {
- struct nlmsghdr nhm;
- struct ifaddrmsg ifa;
- } req = {{sizeof(req), RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP,
- ++rtnl_seq, 0}, {AF_INET6, 0, 0, 0, ifindex}};
- if (send(rtnl_socket, &req, sizeof(req), 0) < (ssize_t)sizeof(req))
- return 0;
+ssize_t odhcpd_get_interface_addresses(int ifindex, bool v6, struct odhcpd_ipaddr **addrs)
+{
+ struct nl_msg *msg;
+ struct ifaddrmsg ifa = {
+ .ifa_family = v6? AF_INET6: AF_INET,
+ .ifa_prefixlen = 0,
+ .ifa_flags = 0,
+ .ifa_scope = 0,
+ .ifa_index = ifindex, };
+ struct nl_cb *cb = nl_cb_alloc(NL_CB_DEFAULT);
+ struct addr_info ctxt = {
+ .ifindex = ifindex,
+ .af = v6? AF_INET6: AF_INET,
+ .addrs = addrs,
+ .ret = 0,
+ .pending = 1,
+ };
- uint8_t buf[8192];
- ssize_t len = 0, ret = 0;
-
- for (struct nlmsghdr *nhm = NULL; ; nhm = NLMSG_NEXT(nhm, len)) {
- while (len < 0 || !NLMSG_OK(nhm, (size_t)len)) {
- len = recv(rtnl_socket, buf, sizeof(buf), 0);
- nhm = (struct nlmsghdr*)buf;
- if (len < 0 || !NLMSG_OK(nhm, (size_t)len)) {
- if (errno == EINTR)
- continue;
- else
- return ret;
- }
- }
+ if (!cb) {
+ ctxt.ret = -1;
+ goto out;
+ }
- if (nhm->nlmsg_type != RTM_NEWADDR)
- break;
+ msg = nlmsg_alloc_simple(RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP);
+
+ if (!msg) {
+ ctxt.ret = - 1;
+ goto out;
+ }
+
+ nlmsg_append(msg, &ifa, sizeof(ifa), 0);
+
+ nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, cb_valid_handler, &ctxt);
+ nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, cb_finish_handler, &ctxt);
+ nl_cb_err(cb, NL_CB_CUSTOM, cb_error_handler, &ctxt);
+
+ nl_send_auto_complete(rtnl_socket, msg);
+ while (ctxt.pending > 0)
+ nl_recvmsgs(rtnl_socket, cb);
+
+ nlmsg_free(msg);
+
+ if (ctxt.ret <= 0)
+ goto out;
+
+ time_t now = odhcpd_time();
+ struct odhcpd_ipaddr *addr = *addrs;
+
+ qsort(addr, ctxt.ret, sizeof(*addr), v6 ? prefix6_cmp : prefix_cmp);
+
+ for (ssize_t i = 0; i < ctxt.ret; ++i) {
+ if (addr[i].preferred < UINT32_MAX - now)
+ addr[i].preferred += now;
+
+ if (addr[i].valid < UINT32_MAX - now)
+ addr[i].valid += now;
+ }
+
+out:
+ nl_cb_put(cb);
+
+ return ctxt.ret;
+}
+
+static int odhcpd_get_linklocal_interface_address(int ifindex, struct in6_addr *lladdr)
+{
+ int status = -1;
+ struct sockaddr_in6 addr = {AF_INET6, 0, 0, ALL_IPV6_ROUTERS, ifindex};
+ socklen_t alen = sizeof(addr);
+ int sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
+
+ if (!connect(sock, (struct sockaddr*)&addr, sizeof(addr)) &&
+ !getsockname(sock, (struct sockaddr*)&addr, &alen)) {
+ *lladdr = addr.sin6_addr;
+ status = 0;
+ }
- // Skip address but keep clearing socket buffer
- if (ret >= (ssize_t)cnt)
+ close(sock);
+
+ return status;
+}
+
+/*
+ * DNS address selection criteria order :
+ * - use IPv6 address with valid lifetime if none is yet selected
+ * - use IPv6 address with a preferred lifetime if the already selected IPv6 address is deprecated
+ * - use an IPv6 ULA address if the already selected IPv6 address is not an ULA address
+ * - use the IPv6 address with the longest preferred lifetime
+ */
+int odhcpd_get_interface_dns_addr(const struct interface *iface, struct in6_addr *addr)
+{
+ time_t now = odhcpd_time();
+ ssize_t m = -1;
+
+ for (size_t i = 0; i < iface->ia_addr_len; ++i) {
+ if (iface->ia_addr[i].valid <= (uint32_t)now)
continue;
- struct ifaddrmsg *ifa = NLMSG_DATA(nhm);
- if (ifa->ifa_scope != RT_SCOPE_UNIVERSE ||
- (ifindex && ifa->ifa_index != (unsigned)ifindex))
+ if (m < 0) {
+ m = i;
continue;
+ }
- struct rtattr *rta = (struct rtattr*)&ifa[1];
- size_t alen = NLMSG_PAYLOAD(nhm, sizeof(*ifa));
- memset(&addrs[ret], 0, sizeof(addrs[ret]));
- addrs[ret].prefix = ifa->ifa_prefixlen;
-
- while (RTA_OK(rta, alen)) {
- if (rta->rta_type == IFA_ADDRESS) {
- memcpy(&addrs[ret].addr, RTA_DATA(rta),
- sizeof(struct in6_addr));
- } else if (rta->rta_type == IFA_CACHEINFO) {
- struct ifa_cacheinfo *ifc = RTA_DATA(rta);
- addrs[ret].preferred = ifc->ifa_prefered;
- addrs[ret].valid = ifc->ifa_valid;
- }
+ if (iface->ia_addr[m].preferred >= (uint32_t)now &&
+ iface->ia_addr[i].preferred < (uint32_t)now)
+ continue;
- rta = RTA_NEXT(rta, alen);
- }
+ if (IN6_IS_ADDR_ULA(&iface->ia_addr[i].addr.in6)) {
+ if (!IN6_IS_ADDR_ULA(&iface->ia_addr[m].addr.in6)) {
+ m = i;
+ continue;
+ }
+ } else if (IN6_IS_ADDR_ULA(&iface->ia_addr[m].addr.in6))
+ continue;
- if (ifa->ifa_flags & IFA_F_DEPRECATED)
- addrs[ret].preferred = 0;
+ if (iface->ia_addr[i].preferred > iface->ia_addr[m].preferred)
+ m = i;
+ }
- ++ret;
+ if (m >= 0) {
+ *addr = iface->ia_addr[m].addr.in6;
+ return 0;
}
- return ret;
+ return odhcpd_get_linklocal_interface_address(iface->ifindex, addr);
}
-int odhcpd_get_preferred_interface_address(int ifindex, struct in6_addr *addr)
+int odhcpd_setup_route(const struct in6_addr *addr, const int prefixlen,
+ const struct interface *iface, const struct in6_addr *gw,
+ const uint32_t metric, const bool add)
{
- struct odhcpd_ipaddr ipaddrs[8];
- ssize_t ip_cnt = odhcpd_get_interface_addresses(ifindex, ipaddrs, ARRAY_SIZE(ipaddrs));
- uint32_t preferred = 0;
+ struct nl_msg *msg;
+ struct rtmsg rtm = {
+ .rtm_family = AF_INET6,
+ .rtm_dst_len = prefixlen,
+ .rtm_src_len = 0,
+ .rtm_table = RT_TABLE_MAIN,
+ .rtm_protocol = (add ? RTPROT_STATIC : RTPROT_UNSPEC),
+ .rtm_scope = (add ? (gw ? RT_SCOPE_UNIVERSE : RT_SCOPE_LINK) : RT_SCOPE_NOWHERE),
+ .rtm_type = (add ? RTN_UNICAST : RTN_UNSPEC),
+ };
int ret = 0;
- for (ssize_t i = 0; i < ip_cnt; i++) {
- struct odhcpd_ipaddr *ipaddr = &ipaddrs[i];
+ msg = nlmsg_alloc_simple(add ? RTM_NEWROUTE : RTM_DELROUTE,
+ add ? NLM_F_CREATE | NLM_F_REPLACE : 0);
+ if (!msg)
+ return -1;
+
+ nlmsg_append(msg, &rtm, sizeof(rtm), 0);
+
+ nla_put(msg, RTA_DST, sizeof(*addr), addr);
+ nla_put_u32(msg, RTA_OIF, iface->ifindex);
+ nla_put_u32(msg, RTA_PRIORITY, metric);
+
+ if (gw)
+ nla_put(msg, RTA_GATEWAY, sizeof(*gw), gw);
+
+ ret = nl_send_auto_complete(rtnl_socket, msg);
+ nlmsg_free(msg);
+
+ if (ret < 0)
+ return ret;
+
+ return nl_wait_for_ack(rtnl_socket);
+}
+
+int odhcpd_setup_proxy_neigh(const struct in6_addr *addr,
+ const struct interface *iface, const bool add)
+{
+ struct nl_msg *msg;
+ struct ndmsg ndm = {
+ .ndm_family = AF_INET6,
+ .ndm_flags = NTF_PROXY,
+ .ndm_ifindex = iface->ifindex,
+ };
+ int ret = 0, flags = NLM_F_REQUEST;
+
+ if (add)
+ flags |= NLM_F_REPLACE | NLM_F_CREATE;
+
+ msg = nlmsg_alloc_simple(add ? RTM_NEWNEIGH : RTM_DELNEIGH, flags);
+ if (!msg)
+ return -1;
+
+ nlmsg_append(msg, &ndm, sizeof(ndm), 0);
- if (ipaddr->preferred > preferred || !preferred) {
- preferred = ipaddr->preferred;
- *addr = ipaddr->addr;
- ret = 1;
+ nla_put(msg, NDA_DST, sizeof(*addr), addr);
+
+ ret = nl_send_auto_complete(rtnl_socket, msg);
+ nlmsg_free(msg);
+
+ if (ret < 0)
+ return ret;
+
+ return nl_wait_for_ack(rtnl_socket);
+}
+
+int odhcpd_setup_addr(struct odhcpd_ipaddr *addr,
+ const struct interface *iface, const bool v6,
+ const bool add)
+{
+ struct nl_msg *msg;
+ struct ifaddrmsg ifa = {
+ .ifa_family = v6 ? AF_INET6 : AF_INET,
+ .ifa_prefixlen = addr->prefix,
+ .ifa_flags = 0,
+ .ifa_scope = 0,
+ .ifa_index = iface->ifindex, };
+ int ret = 0, flags = NLM_F_REQUEST;
+
+ if (add)
+ flags |= NLM_F_REPLACE | NLM_F_CREATE;
+
+ msg = nlmsg_alloc_simple(add ? RTM_NEWADDR : RTM_DELADDR, 0);
+ if (!msg)
+ return -1;
+
+ nlmsg_append(msg, &ifa, sizeof(ifa), flags);
+ nla_put(msg, IFA_LOCAL, v6 ? 16 : 4, &addr->addr);
+ if (v6) {
+ struct ifa_cacheinfo cinfo = { .ifa_prefered = 0xffffffffU,
+ .ifa_valid = 0xffffffffU,
+ .cstamp = 0,
+ .tstamp = 0 };
+ time_t now = odhcpd_time();
+
+ if (addr->preferred) {
+ int64_t preferred = addr->preferred - now;
+ if (preferred < 0)
+ preferred = 0;
+ else if (preferred > UINT32_MAX)
+ preferred = UINT32_MAX;
+
+ cinfo.ifa_prefered = preferred;
}
+
+ if (addr->valid) {
+ int64_t valid = addr->valid - now;
+ if (valid <= 0) {
+ nlmsg_free(msg);
+ return -1;
+ }
+ else if (valid > UINT32_MAX)
+ valid = UINT32_MAX;
+
+ cinfo.ifa_valid = valid;
+ }
+
+ nla_put(msg, IFA_CACHEINFO, sizeof(cinfo), &cinfo);
+
+ nla_put_u32(msg, IFA_FLAGS, IFA_F_NOPREFIXROUTE);
+ } else {
+ if (addr->broadcast.s_addr)
+ nla_put_u32(msg, IFA_BROADCAST, addr->broadcast.s_addr);
}
- return ret;
+ ret = nl_send_auto_complete(rtnl_socket, msg);
+ nlmsg_free(msg);
+
+ if (ret < 0)
+ return ret;
+
+ return nl_wait_for_ack(rtnl_socket);
}
struct interface* odhcpd_get_interface_by_index(int ifindex)
{
struct odhcpd_event *e = container_of(u, struct odhcpd_event, uloop);
- uint8_t data_buf[RELAYD_BUFFER_SIZE], cmsg_buf[128];
+ uint8_t data_buf[8192], cmsg_buf[128];
union {
struct sockaddr_in6 in6;
struct sockaddr_in in;
struct sockaddr_nl nl;
} addr;
+ if (u->error) {
+ int ret = -1;
+ socklen_t ret_len = sizeof(ret);
+ getsockopt(u->fd, SOL_SOCKET, SO_ERROR, &ret, &ret_len);
+ u->error = false;
+ if (e->handle_error)
+ e->handle_error(e, ret);
+ }
+
+ if (e->recv_msgs) {
+ e->recv_msgs(e);
+ return;
+ }
+
while (true) {
struct iovec iov = {data_buf, sizeof(data_buf)};
struct msghdr msg = {
else if (addr.in.sin_family == AF_INET)
inet_ntop(AF_INET, &addr.in.sin_addr, ipbuf, sizeof(ipbuf));
- syslog(LOG_DEBUG, "--");
syslog(LOG_DEBUG, "Received %li Bytes from %s%%%s", (long)len,
ipbuf, (iface) ? iface->ifname : "netlink");
int odhcpd_register(struct odhcpd_event *event)
{
event->uloop.cb = odhcpd_receive_packets;
- return uloop_fd_add(&event->uloop, ULOOP_READ);
+ return uloop_fd_add(&event->uloop, ULOOP_READ |
+ ((event->handle_error) ? ULOOP_ERROR_CB : 0));
+}
+
+int odhcpd_deregister(struct odhcpd_event *event)
+{
+ event->uloop.cb = NULL;
+ return uloop_fd_delete(&event->uloop);
}
void odhcpd_process(struct odhcpd_event *event)
a[bytes] = (a[bytes] & mask) | ((~mask) & b[bytes]);
}
}
+
+
+int odhcpd_netmask2bitlen(bool inet6, void *mask)
+{
+ int bits;
+ struct in_addr *v4;
+ struct in6_addr *v6;
+
+ if (inet6)
+ for (bits = 0, v6 = mask;
+ bits < 128 && (v6->s6_addr[bits / 8] << (bits % 8)) & 128;
+ bits++);
+ else
+ for (bits = 0, v4 = mask;
+ bits < 32 && (ntohl(v4->s_addr) << bits) & 0x80000000;
+ bits++);
+
+ return bits;
+}
+
+bool odhcpd_bitlen2netmask(bool inet6, unsigned int bits, void *mask)
+{
+ uint8_t b;
+ struct in_addr *v4;
+ struct in6_addr *v6;
+
+ if (inet6)
+ {
+ if (bits > 128)
+ return false;
+
+ v6 = mask;
+
+ for (unsigned int i = 0; i < sizeof(v6->s6_addr); i++)
+ {
+ b = (bits > 8) ? 8 : bits;
+ v6->s6_addr[i] = (uint8_t)(0xFF << (8 - b));
+ bits -= b;
+ }
+ }
+ else
+ {
+ if (bits > 32)
+ return false;
+
+ v4 = mask;
+ v4->s_addr = bits ? htonl(~((1 << (32 - bits)) - 1)) : 0;
+ }
+
+ return true;
+}