#include <errno.h>
#include <string.h>
+#include <sys/ioctl.h>
+#include "udev.h"
+#include "udev-util.h"
+#include "virt.h"
+#include "siphash24.h"
#include "util.h"
#include "refcnt.h"
+#include "network-internal.h"
#include "sd-dhcp6-client.h"
#include "dhcp6-protocol.h"
+#include "dhcp6-internal.h"
+#include "dhcp6-lease-internal.h"
+
+#define SYSTEMD_PEN 43793
+#define HASH_KEY SD_ID128_MAKE(80,11,8c,c2,fe,4a,03,ee,3e,d6,0c,6f,36,39,14,09)
struct sd_dhcp6_client {
RefCount n_ref;
int event_priority;
int index;
struct ether_addr mac_addr;
+ DHCP6IA ia_na;
+ be32_t transaction_id;
+ struct sd_dhcp6_lease *lease;
+ int fd;
+ sd_event_source *receive_message;
+ usec_t retransmit_time;
+ uint8_t retransmit_count;
+ sd_event_source *timeout_resend;
+ sd_event_source *timeout_resend_expire;
sd_dhcp6_client_cb_t cb;
void *userdata;
+
+ struct duid_en {
+ uint16_t type; /* DHCP6_DUID_EN */
+ uint32_t pen;
+ uint8_t id[8];
+ } _packed_ duid;
+};
+
+const char * dhcp6_message_type_table[_DHCP6_MESSAGE_MAX] = {
+ [DHCP6_SOLICIT] = "SOLICIT",
+ [DHCP6_ADVERTISE] = "ADVERTISE",
+ [DHCP6_REQUEST] = "REQUEST",
+ [DHCP6_CONFIRM] = "CONFIRM",
+ [DHCP6_RENEW] = "RENEW",
+ [DHCP6_REBIND] = "REBIND",
+ [DHCP6_REPLY] = "REPLY",
+ [DHCP6_RELEASE] = "RELEASE",
+ [DHCP6_DECLINE] = "DECLINE",
+ [DHCP6_RECONFIGURE] = "RECONFIGURE",
+ [DHCP6_INFORMATION_REQUEST] = "INFORMATION-REQUEST",
+ [DHCP6_RELAY_FORW] = "RELAY-FORW",
+ [DHCP6_RELAY_REPL] = "RELAY-REPL",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(dhcp6_message_type, int);
+
+const char * dhcp6_message_status_table[_DHCP6_STATUS_MAX] = {
+ [DHCP6_STATUS_SUCCESS] = "Success",
+ [DHCP6_STATUS_UNSPEC_FAIL] = "Unspecified failure",
+ [DHCP6_STATUS_NO_ADDRS_AVAIL] = "No addresses available",
+ [DHCP6_STATUS_NO_BINDING] = "Binding unavailable",
+ [DHCP6_STATUS_NOT_ON_LINK] = "Not on link",
+ [DHCP6_STATUS_USE_MULTICAST] = "Use multicast",
};
+DEFINE_STRING_TABLE_LOOKUP(dhcp6_message_status, int);
+
+static int client_start(sd_dhcp6_client *client, enum DHCP6State state);
+
int sd_dhcp6_client_set_callback(sd_dhcp6_client *client,
sd_dhcp6_client_cb_t cb, void *userdata)
{
return 0;
}
+int sd_dhcp6_client_get_lease(sd_dhcp6_client *client, sd_dhcp6_lease **ret) {
+ assert_return(client, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ if (!client->lease)
+ return -ENOMSG;
+
+ *ret = sd_dhcp6_lease_ref(client->lease);
+
+ return 0;
+}
+
static sd_dhcp6_client *client_notify(sd_dhcp6_client *client, int event) {
if (client->cb) {
client = sd_dhcp6_client_ref(client);
{
assert_return(client, -EINVAL);
+ client->receive_message =
+ sd_event_source_unref(client->receive_message);
+
+ if (client->fd > 0)
+ client->fd = safe_close(client->fd);
+
+ client->transaction_id = 0;
+
+ client->ia_na.timeout_t1 =
+ sd_event_source_unref(client->ia_na.timeout_t1);
+ client->ia_na.timeout_t2 =
+ sd_event_source_unref(client->ia_na.timeout_t2);
+
+ client->retransmit_time = 0;
+ client->retransmit_count = 0;
+ client->timeout_resend = sd_event_source_unref(client->timeout_resend);
+ client->timeout_resend_expire =
+ sd_event_source_unref(client->timeout_resend_expire);
+
client->state = DHCP6_STATE_STOPPED;
return 0;
return client;
}
+static int client_send_message(sd_dhcp6_client *client) {
+ _cleanup_free_ DHCP6Message *message = NULL;
+ struct in6_addr all_servers =
+ IN6ADDR_ALL_DHCP6_RELAY_AGENTS_AND_SERVERS_INIT;
+ size_t len, optlen = 512;
+ uint8_t *opt;
+ int r;
+
+ len = sizeof(DHCP6Message) + optlen;
+
+ message = malloc0(len);
+ if (!message)
+ return -ENOMEM;
+
+ opt = (uint8_t *)(message + 1);
+
+ message->transaction_id = client->transaction_id;
+
+ switch(client->state) {
+ case DHCP6_STATE_SOLICITATION:
+ message->type = DHCP6_SOLICIT;
+
+ r = dhcp6_option_append(&opt, &optlen, DHCP6_OPTION_CLIENTID,
+ sizeof(client->duid), &client->duid);
+ if (r < 0)
+ return r;
+
+ r = dhcp6_option_append_ia(&opt, &optlen, &client->ia_na);
+ if (r < 0)
+ return r;
+
+ break;
+
+ case DHCP6_STATE_STOPPED:
+ case DHCP6_STATE_RS:
+ return -EINVAL;
+ }
+
+ r = dhcp6_network_send_udp_socket(client->fd, &all_servers, message,
+ len - optlen);
+ if (r < 0)
+ return r;
+
+ log_dhcp6_client(client, "Sent %s",
+ dhcp6_message_type_to_string(message->type));
+
+ return 0;
+}
+
+static int client_timeout_resend_expire(sd_event_source *s, uint64_t usec,
+ void *userdata) {
+ sd_dhcp6_client *client = userdata;
+
+ assert(s);
+ assert(client);
+ assert(client->event);
+
+ client_stop(client, DHCP6_EVENT_RESEND_EXPIRE);
+
+ return 0;
+}
+
+static usec_t client_timeout_compute_random(usec_t val) {
+ return val - val / 10 +
+ (random_u32() % (2 * USEC_PER_SEC)) * val / 10 / USEC_PER_SEC;
+}
+
+static int client_timeout_resend(sd_event_source *s, uint64_t usec,
+ void *userdata) {
+ int r = 0;
+ sd_dhcp6_client *client = userdata;
+ usec_t time_now, init_retransmit_time, max_retransmit_time;
+ usec_t max_retransmit_duration;
+ uint8_t max_retransmit_count;
+ char time_string[FORMAT_TIMESPAN_MAX];
+
+ assert(s);
+ assert(client);
+ assert(client->event);
+
+ client->timeout_resend = sd_event_source_unref(client->timeout_resend);
+
+ switch (client->state) {
+ case DHCP6_STATE_SOLICITATION:
+ init_retransmit_time = DHCP6_SOL_TIMEOUT;
+ max_retransmit_time = DHCP6_SOL_MAX_RT;
+ max_retransmit_count = 0;
+ max_retransmit_duration = 0;
+
+ break;
+
+ case DHCP6_STATE_STOPPED:
+ case DHCP6_STATE_RS:
+ return 0;
+ }
+
+ if (max_retransmit_count &&
+ client->retransmit_count >= max_retransmit_count) {
+ client_stop(client, DHCP6_EVENT_RETRANS_MAX);
+ return 0;
+ }
+
+ r = client_send_message(client);
+ if (r >= 0)
+ client->retransmit_count++;
+
+
+ r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now);
+ if (r < 0)
+ goto error;
+
+ if (!client->retransmit_time) {
+ client->retransmit_time =
+ client_timeout_compute_random(init_retransmit_time);
+
+ if (client->state == DHCP6_STATE_SOLICITATION)
+ client->retransmit_time += init_retransmit_time / 10;
+
+ } else {
+ if (max_retransmit_time &&
+ client->retransmit_time > max_retransmit_time / 2)
+ client->retransmit_time = client_timeout_compute_random(max_retransmit_time);
+ else
+ client->retransmit_time += client_timeout_compute_random(client->retransmit_time);
+ }
+
+ log_dhcp6_client(client, "Next retransmission in %s",
+ format_timespan(time_string, FORMAT_TIMESPAN_MAX,
+ client->retransmit_time, 0));
+
+ r = sd_event_add_time(client->event, &client->timeout_resend,
+ CLOCK_MONOTONIC,
+ time_now + client->retransmit_time,
+ 10 * USEC_PER_MSEC, client_timeout_resend,
+ client);
+ if (r < 0)
+ goto error;
+
+ r = sd_event_source_set_priority(client->timeout_resend,
+ client->event_priority);
+ if (r < 0)
+ goto error;
+
+ if (max_retransmit_duration && !client->timeout_resend_expire) {
+
+ log_dhcp6_client(client, "Max retransmission duration %"PRIu64" secs",
+ max_retransmit_duration / USEC_PER_SEC);
+
+ r = sd_event_add_time(client->event,
+ &client->timeout_resend_expire,
+ CLOCK_MONOTONIC,
+ time_now + max_retransmit_duration,
+ USEC_PER_SEC,
+ client_timeout_resend_expire, client);
+ if (r < 0)
+ goto error;
+
+ r = sd_event_source_set_priority(client->timeout_resend_expire,
+ client->event_priority);
+ if (r < 0)
+ goto error;
+ }
+
+error:
+ if (r < 0)
+ client_stop(client, r);
+
+ return 0;
+}
+
+static int client_ensure_iaid(sd_dhcp6_client *client) {
+ const char *name = NULL;
+ uint64_t id;
+
+ assert(client);
+
+ if (client->ia_na.id)
+ return 0;
+
+ if (detect_container(NULL) <= 0) {
+ /* not in a container, udev will be around */
+ _cleanup_udev_unref_ struct udev *udev;
+ _cleanup_udev_device_unref_ struct udev_device *device;
+ char ifindex_str[2 + DECIMAL_STR_MAX(int)];
+
+ udev = udev_new();
+ if (!udev)
+ return -ENOMEM;
+
+ sprintf(ifindex_str, "n%d", client->index);
+ device = udev_device_new_from_device_id(udev, ifindex_str);
+ if (!device)
+ return -errno;
+
+ if (udev_device_get_is_initialized(device) <= 0)
+ /* not yet ready */
+ return -EBUSY;
+
+ name = net_get_name(device);
+ }
+
+ if (name)
+ siphash24((uint8_t*)&id, name, strlen(name), HASH_KEY.bytes);
+ else
+ /* fall back to mac address if no predictable name available */
+ siphash24((uint8_t*)&id, &client->mac_addr, ETH_ALEN,
+ HASH_KEY.bytes);
+
+ /* fold into 32 bits */
+ client->ia_na.id = (id & 0xffffffff) ^ (id >> 32);
+
+ return 0;
+}
+
+static int client_parse_message(sd_dhcp6_client *client,
+ DHCP6Message *message, size_t len,
+ sd_dhcp6_lease *lease) {
+ int r;
+ uint8_t *optval, *option = (uint8_t *)(message + 1), *id = NULL;
+ uint16_t optcode, status;
+ size_t optlen, id_len;
+ bool clientid = false;
+ be32_t iaid_lease;
+
+ while ((r = dhcp6_option_parse(&option, &len, &optcode, &optlen,
+ &optval)) >= 0) {
+ switch (optcode) {
+ case DHCP6_OPTION_CLIENTID:
+ if (clientid) {
+ log_dhcp6_client(client, "%s contains multiple clientids",
+ dhcp6_message_type_to_string(message->type));
+ return -EINVAL;
+ }
+
+ if (optlen != sizeof(client->duid) ||
+ memcmp(&client->duid, optval, optlen) != 0) {
+ log_dhcp6_client(client, "%s DUID does not match",
+ dhcp6_message_type_to_string(message->type));
+
+ return -EINVAL;
+ }
+ clientid = true;
+
+ break;
+
+ case DHCP6_OPTION_SERVERID:
+ r = dhcp6_lease_get_serverid(lease, &id, &id_len);
+ if (r >= 0 && id) {
+ log_dhcp6_client(client, "%s contains multiple serverids",
+ dhcp6_message_type_to_string(message->type));
+ return -EINVAL;
+ }
+
+ r = dhcp6_lease_set_serverid(lease, optval, optlen);
+ if (r < 0)
+ return r;
+
+ break;
+
+ case DHCP6_OPTION_PREFERENCE:
+ if (optlen != 1)
+ return -EINVAL;
+
+ r = dhcp6_lease_set_preference(lease, *optval);
+ if (r < 0)
+ return r;
+
+ break;
+
+ case DHCP6_OPTION_STATUS_CODE:
+ if (optlen < 2)
+ return -EINVAL;
+
+ status = optval[0] << 8 | optval[1];
+ if (status) {
+ log_dhcp6_client(client, "%s Status %s",
+ dhcp6_message_type_to_string(message->type),
+ dhcp6_message_status_to_string(status));
+ return -EINVAL;
+ }
+
+ break;
+
+ case DHCP6_OPTION_IA_NA:
+ r = dhcp6_option_parse_ia(&optval, &optlen, optcode,
+ &lease->ia);
+ if (r < 0 && r != -ENOMSG)
+ return r;
+
+ r = dhcp6_lease_get_iaid(lease, &iaid_lease);
+ if (r < 0)
+ return r;
+
+ if (client->ia_na.id != iaid_lease) {
+ log_dhcp6_client(client, "%s has wrong IAID",
+ dhcp6_message_type_to_string(message->type));
+ return -EINVAL;
+ }
+
+ break;
+ }
+ }
+
+ if ((r < 0 && r != -ENOMSG) || !clientid) {
+ log_dhcp6_client(client, "%s has incomplete options",
+ dhcp6_message_type_to_string(message->type));
+ return -EINVAL;
+ }
+
+ r = dhcp6_lease_get_serverid(lease, &id, &id_len);
+ if (r < 0)
+ log_dhcp6_client(client, "%s has no server id",
+ dhcp6_message_type_to_string(message->type));
+
+ return r;
+}
+
+static int client_receive_advertise(sd_dhcp6_client *client,
+ DHCP6Message *advertise, size_t len) {
+ int r;
+ _cleanup_dhcp6_lease_free_ sd_dhcp6_lease *lease = NULL;
+ uint8_t pref_advertise = 0, pref_lease = 0;
+
+ if (advertise->type != DHCP6_ADVERTISE)
+ return -EINVAL;
+
+ r = dhcp6_lease_new(&lease);
+ if (r < 0)
+ return r;
+
+ r = client_parse_message(client, advertise, len, lease);
+ if (r < 0)
+ return r;
+
+ r = dhcp6_lease_get_preference(lease, &pref_advertise);
+ if (r < 0)
+ return r;
+
+ r = dhcp6_lease_get_preference(client->lease, &pref_lease);
+ if (!client->lease || r < 0 || pref_advertise > pref_lease) {
+ sd_dhcp6_lease_unref(client->lease);
+ client->lease = lease;
+ lease = NULL;
+ r = 0;
+ }
+
+ return r;
+}
+
+static int client_receive_message(sd_event_source *s, int fd, uint32_t revents,
+ void *userdata) {
+ sd_dhcp6_client *client = userdata;
+ _cleanup_free_ DHCP6Message *message;
+ int r, buflen, len;
+
+ assert(s);
+ assert(client);
+ assert(client->event);
+
+ r = ioctl(fd, FIONREAD, &buflen);
+ if (r < 0 || buflen <= 0)
+ buflen = DHCP6_MIN_OPTIONS_SIZE;
+
+ message = malloc0(buflen);
+ if (!message)
+ return -ENOMEM;
+
+ len = read(fd, message, buflen);
+ if ((size_t)len < sizeof(DHCP6Message)) {
+ log_dhcp6_client(client, "could not receive message from UDP socket: %s", strerror(errno));
+ return 0;
+ }
+
+ switch(message->type) {
+ case DHCP6_SOLICIT:
+ case DHCP6_REQUEST:
+ case DHCP6_CONFIRM:
+ case DHCP6_RENEW:
+ case DHCP6_REBIND:
+ case DHCP6_RELEASE:
+ case DHCP6_DECLINE:
+ case DHCP6_INFORMATION_REQUEST:
+ case DHCP6_RELAY_FORW:
+ case DHCP6_RELAY_REPL:
+ return 0;
+
+ case DHCP6_ADVERTISE:
+ case DHCP6_REPLY:
+ case DHCP6_RECONFIGURE:
+ break;
+
+ default:
+ log_dhcp6_client(client, "unknown message type %d",
+ message->type);
+ return 0;
+ }
+
+ if (client->transaction_id != (message->transaction_id &
+ htobe32(0x00ffffff)))
+ return 0;
+
+ switch (client->state) {
+ case DHCP6_STATE_SOLICITATION:
+ r = client_receive_advertise(client, message, len);
+
+ break;
+
+ case DHCP6_STATE_STOPPED:
+ case DHCP6_STATE_RS:
+ return 0;
+ }
+
+ if (r >= 0) {
+ log_dhcp6_client(client, "Recv %s",
+ dhcp6_message_type_to_string(message->type));
+ }
+
+ return 0;
+}
+
+static int client_start(sd_dhcp6_client *client, enum DHCP6State state)
+{
+ int r;
+
+ assert_return(client, -EINVAL);
+ assert_return(client->event, -EINVAL);
+ assert_return(client->index > 0, -EINVAL);
+ assert_return(client->state != state, -EINVAL);
+
+ client->timeout_resend_expire =
+ sd_event_source_unref(client->timeout_resend_expire);
+ client->timeout_resend = sd_event_source_unref(client->timeout_resend);
+ client->retransmit_time = 0;
+ client->retransmit_count = 0;
+
+ switch (state) {
+ case DHCP6_STATE_STOPPED:
+ case DHCP6_STATE_RS:
+ case DHCP6_STATE_SOLICITATION:
+
+ r = client_ensure_iaid(client);
+ if (r < 0)
+ return r;
+
+ r = dhcp6_network_bind_udp_socket(client->index, NULL);
+ if (r < 0)
+ return r;
+
+ client->fd = r;
+
+ r = sd_event_add_io(client->event, &client->receive_message,
+ client->fd, EPOLLIN, client_receive_message,
+ client);
+ if (r < 0)
+ return r;
+
+ r = sd_event_source_set_priority(client->receive_message,
+ client->event_priority);
+ if (r < 0)
+ return r;
+
+ client->state = DHCP6_STATE_SOLICITATION;
+
+ break;
+ }
+
+ client->transaction_id = random_u32() & htobe32(0x00ffffff);
+
+ r = sd_event_add_time(client->event, &client->timeout_resend,
+ CLOCK_MONOTONIC, 0, 0, client_timeout_resend,
+ client);
+ if (r < 0)
+ return r;
+
+ r = sd_event_source_set_priority(client->timeout_resend,
+ client->event_priority);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
int sd_dhcp6_client_stop(sd_dhcp6_client *client)
{
client_stop(client, DHCP6_EVENT_STOP);
assert_return(client->event, -EINVAL);
assert_return(client->index > 0, -EINVAL);
- return r;
+ r = client_initialize(client);
+ if (r < 0)
+ return r;
+
+ return client_start(client, DHCP6_STATE_SOLICITATION);
}
int sd_dhcp6_client_attach_event(sd_dhcp6_client *client, sd_event *event,
sd_dhcp6_client *sd_dhcp6_client_unref(sd_dhcp6_client *client) {
if (client && REFCNT_DEC(client->n_ref) <= 0) {
-
client_initialize(client);
sd_dhcp6_client_detach_event(client);
int sd_dhcp6_client_new(sd_dhcp6_client **ret)
{
_cleanup_dhcp6_client_free_ sd_dhcp6_client *client = NULL;
+ sd_id128_t machine_id;
+ int r;
assert_return(ret, -EINVAL);
client->n_ref = REFCNT_INIT;
+ client->ia_na.type = DHCP6_OPTION_IA_NA;
+
client->index = -1;
+ /* initialize DUID */
+ client->duid.type = htobe16(DHCP6_DUID_EN);
+ client->duid.pen = htobe32(SYSTEMD_PEN);
+
+ r = sd_id128_get_machine(&machine_id);
+ if (r < 0)
+ return r;
+
+ /* a bit of snake-oil perhaps, but no need to expose the machine-id
+ directly */
+ siphash24(client->duid.id, &machine_id, sizeof(machine_id),
+ HASH_KEY.bytes);
+
*ret = client;
client = NULL;