X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Flibsystemd-network%2Fsd-dhcp6-client.c;h=1a59cc286179d8007efd3b622212d30ca426608d;hb=c3e2adeaba8e043caed0ef139eeaea016bd152d0;hp=15d174beee2c256561a3d60a5899a65254c227b3;hpb=f12abb48fc510b8b349c05e35ba048134debaf25;p=elogind.git

diff --git a/src/libsystemd-network/sd-dhcp6-client.c b/src/libsystemd-network/sd-dhcp6-client.c
index 15d174bee..1a59cc286 100644
--- a/src/libsystemd-network/sd-dhcp6-client.c
+++ b/src/libsystemd-network/sd-dhcp6-client.c
@@ -21,6 +21,7 @@
 
 #include <errno.h>
 #include <string.h>
+#include <sys/ioctl.h>
 
 #include "udev.h"
 #include "udev-util.h"
@@ -33,6 +34,7 @@
 #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)
@@ -46,6 +48,14 @@ struct sd_dhcp6_client {
         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;
 
@@ -56,6 +66,37 @@ struct sd_dhcp6_client {
         } _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)
 {
@@ -90,6 +131,18 @@ int sd_dhcp6_client_set_mac(sd_dhcp6_client *client,
         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);
@@ -104,11 +157,25 @@ static int client_initialize(sd_dhcp6_client *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;
@@ -124,6 +191,176 @@ static sd_dhcp6_client *client_stop(sd_dhcp6_client *client, int error) {
         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;
@@ -168,15 +405,268 @@ static int client_ensure_iaid(sd_dhcp6_client *client) {
         return 0;
 }
 
-static int client_start(sd_dhcp6_client *client)
+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 = client_ensure_iaid(client);
+        r = sd_event_source_set_priority(client->timeout_resend,
+                                         client->event_priority);
         if (r < 0)
                 return r;
 
@@ -202,7 +692,7 @@ int sd_dhcp6_client_start(sd_dhcp6_client *client)
         if (r < 0)
                 return r;
 
-        return client_start(client);
+        return client_start(client, DHCP6_STATE_SOLICITATION);
 }
 
 int sd_dhcp6_client_attach_event(sd_dhcp6_client *client, sd_event *event,