[thirdparty/systemd.git] / src / libsystemd-network / sd-ndisc.c

/***
  This file is part of systemd.

  Copyright (C) 2014 Intel Corporation. All rights reserved.

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <netinet/icmp6.h>
#include <netinet/in.h>

#include "sd-ndisc.h"

#include "alloc-util.h"
#include "fd-util.h"
#include "icmp6-util.h"
#include "in-addr-util.h"
#include "ndisc-internal.h"
#include "ndisc-router.h"
#include "random-util.h"
#include "socket-util.h"
#include "string-util.h"
#include "util.h"

#define NDISC_TIMEOUT_NO_RA_USEC (NDISC_ROUTER_SOLICITATION_INTERVAL * NDISC_MAX_ROUTER_SOLICITATIONS)

static void ndisc_callback(sd_ndisc *ndisc, sd_ndisc_event event, sd_ndisc_router *rt) {
        assert(ndisc);

        log_ndisc("Invoking callback for '%c'.", event);

        if (!ndisc->callback)
                return;

        ndisc->callback(ndisc, event, rt, ndisc->userdata);
}

_public_ int sd_ndisc_set_callback(
                sd_ndisc *nd,
                sd_ndisc_callback_t callback,
                void *userdata) {

        assert_return(nd, -EINVAL);

        nd->callback = callback;
        nd->userdata = userdata;

        return 0;
}

_public_ int sd_ndisc_set_ifindex(sd_ndisc *nd, int ifindex) {
        assert_return(nd, -EINVAL);
        assert_return(ifindex > 0, -EINVAL);
        assert_return(nd->fd < 0, -EBUSY);

        nd->ifindex = ifindex;
        return 0;
}

_public_ int sd_ndisc_set_mac(sd_ndisc *nd, const struct ether_addr *mac_addr) {
        assert_return(nd, -EINVAL);

        if (mac_addr)
                nd->mac_addr = *mac_addr;
        else
                zero(nd->mac_addr);

        return 0;
}

_public_ int sd_ndisc_attach_event(sd_ndisc *nd, sd_event *event, int64_t priority) {
        int r;

        assert_return(nd, -EINVAL);
        assert_return(nd->fd < 0, -EBUSY);
        assert_return(!nd->event, -EBUSY);

        if (event)
                nd->event = sd_event_ref(event);
        else {
                r = sd_event_default(&nd->event);
                if (r < 0)
                        return 0;
        }

        nd->event_priority = priority;

        return 0;
}

_public_ int sd_ndisc_detach_event(sd_ndisc *nd) {

        assert_return(nd, -EINVAL);
        assert_return(nd->fd < 0, -EBUSY);

        nd->event = sd_event_unref(nd->event);
        return 0;
}

_public_ sd_event *sd_ndisc_get_event(sd_ndisc *nd) {
        assert_return(nd, NULL);

        return nd->event;
}

_public_ sd_ndisc *sd_ndisc_ref(sd_ndisc *nd) {

        if (!nd)
                return NULL;

        assert(nd->n_ref > 0);
        nd->n_ref++;

        return nd;
}

static int ndisc_reset(sd_ndisc *nd) {
        assert(nd);

        nd->timeout_event_source = sd_event_source_unref(nd->timeout_event_source);
        nd->timeout_no_ra = sd_event_source_unref(nd->timeout_no_ra);
        nd->retransmit_time = 0;
        nd->recv_event_source = sd_event_source_unref(nd->recv_event_source);
        nd->fd = safe_close(nd->fd);

        return 0;
}

_public_ sd_ndisc *sd_ndisc_unref(sd_ndisc *nd) {

        if (!nd)
                return NULL;

        assert(nd->n_ref > 0);
        nd->n_ref--;

        if (nd->n_ref > 0)
                return NULL;

        ndisc_reset(nd);
        sd_ndisc_detach_event(nd);
        return mfree(nd);
}

_public_ int sd_ndisc_new(sd_ndisc **ret) {
        _cleanup_(sd_ndisc_unrefp) sd_ndisc *nd = NULL;

        assert_return(ret, -EINVAL);

        nd = new0(sd_ndisc, 1);
        if (!nd)
                return -ENOMEM;

        nd->n_ref = 1;
        nd->fd = -1;

        *ret = nd;
        nd = NULL;

        return 0;
}

_public_ int sd_ndisc_get_mtu(sd_ndisc *nd, uint32_t *mtu) {
        assert_return(nd, -EINVAL);
        assert_return(mtu, -EINVAL);

        if (nd->mtu == 0)
                return -ENODATA;

        *mtu = nd->mtu;
        return 0;
}

_public_ int sd_ndisc_get_hop_limit(sd_ndisc *nd, uint8_t *ret) {
        assert_return(nd, -EINVAL);
        assert_return(ret, -EINVAL);

        if (nd->hop_limit == 0)
                return -ENODATA;

        *ret = nd->hop_limit;
        return 0;
}

static int ndisc_handle_datagram(sd_ndisc *nd, sd_ndisc_router *rt) {
        int r;

        assert(nd);
        assert(rt);

        r = ndisc_router_parse(rt);
        if (r == -EBADMSG) /* Bad packet */
                return 0;
        if (r < 0)
                return 0;

        /* Update global variables we keep */
        if (rt->mtu > 0)
                nd->mtu = rt->mtu;
        if (rt->hop_limit > 0)
                nd->hop_limit = rt->hop_limit;

        log_ndisc("Received Router Advertisement: flags %s preference %s lifetime %" PRIu16 " sec",
                  rt->flags & ND_RA_FLAG_MANAGED ? "MANAGED" : rt->flags & ND_RA_FLAG_OTHER ? "OTHER" : "none",
                  rt->preference == SD_NDISC_PREFERENCE_HIGH ? "high" : rt->preference == SD_NDISC_PREFERENCE_LOW ? "low" : "medium",
                  rt->lifetime);

        ndisc_callback(nd, SD_NDISC_EVENT_ROUTER, rt);
        return 0;
}

static int ndisc_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
        _cleanup_(sd_ndisc_router_unrefp) sd_ndisc_router *rt = NULL;
        sd_ndisc *nd = userdata;
        ssize_t buflen;
        int r;
        _cleanup_free_ char *addr = NULL;

        assert(s);
        assert(nd);
        assert(nd->event);

        buflen = next_datagram_size_fd(fd);
        if (buflen < 0)
                return log_ndisc_errno(buflen, "Failed to determine datagram size to read: %m");

        rt = ndisc_router_new(buflen);
        if (!rt)
                return -ENOMEM;

        r = icmp6_receive(fd, NDISC_ROUTER_RAW(rt), rt->raw_size, &rt->address,
                     &rt->timestamp);
        if (r < 0) {
                switch (r) {
                case -EADDRNOTAVAIL:
                        (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &rt->address, &addr);
                        log_ndisc("Received RA from non-link-local address %s. Ignoring", addr);
                        break;

                case -EMULTIHOP:
                        log_ndisc("Received RA with invalid hop limit. Ignoring.");
                        break;

                case -EPFNOSUPPORT:
                        log_ndisc("Received invalid source address from ICMPv6 socket.");
                        break;
                }

                return 0;
        }

        nd->timeout_event_source = sd_event_source_unref(nd->timeout_event_source);

        return ndisc_handle_datagram(nd, rt);
}

static usec_t ndisc_timeout_compute_random(usec_t val) {
        /* compute a time that is random within ±10% of the given value */
        return val - val / 10 +
                (random_u64() % (2 * USEC_PER_SEC)) * val / 10 / USEC_PER_SEC;
}

static int ndisc_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
        sd_ndisc *nd = userdata;
        usec_t time_now;
        int r;
        char time_string[FORMAT_TIMESPAN_MAX];

        assert(s);
        assert(nd);
        assert(nd->event);

        r = icmp6_send_router_solicitation(nd->fd, &nd->mac_addr);
        if (r < 0) {
                log_ndisc_errno(r, "Error sending Router Solicitation: %m");
                goto fail;
        }

        assert_se(sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now) >= 0);

        nd->timeout_event_source = sd_event_source_unref(nd->timeout_event_source);

        if (!nd->retransmit_time)
                nd->retransmit_time = ndisc_timeout_compute_random(NDISC_ROUTER_SOLICITATION_INTERVAL);
        else {
                if (nd->retransmit_time > NDISC_MAX_ROUTER_SOLICITATION_INTERVAL / 2)
                        nd->retransmit_time = ndisc_timeout_compute_random(NDISC_MAX_ROUTER_SOLICITATION_INTERVAL);
                else
                        nd->retransmit_time += ndisc_timeout_compute_random(nd->retransmit_time);
        }

        r = sd_event_add_time(nd->event, &nd->timeout_event_source,
                              clock_boottime_or_monotonic(),
                              time_now + nd->retransmit_time,
                              10 * USEC_PER_MSEC, ndisc_timeout, nd);
        if (r < 0)
                goto fail;

        r = sd_event_source_set_priority(nd->timeout_event_source, nd->event_priority);
        if (r < 0)
                goto fail;

        (void) sd_event_source_set_description(nd->timeout_event_source, "ndisc-timeout-no-ra");

        r = sd_event_source_set_enabled(nd->timeout_event_source, SD_EVENT_ONESHOT);
        if (r < 0) {
                log_ndisc_errno(r, "Error reenabling timer: %m");
                goto fail;
        }

        log_ndisc("Sent Router Solicitation, next solicitation in %s",
                  format_timespan(time_string, FORMAT_TIMESPAN_MAX,
                                  nd->retransmit_time, USEC_PER_SEC));

        return 0;

fail:
        sd_ndisc_stop(nd);
        return 0;
}

static int ndisc_timeout_no_ra(sd_event_source *s, uint64_t usec, void *userdata) {
        sd_ndisc *nd = userdata;

        assert(s);
        assert(nd);

        log_ndisc("No RA received before link confirmation timeout");

        nd->timeout_no_ra = sd_event_source_unref(nd->timeout_no_ra);
        ndisc_callback(nd, SD_NDISC_EVENT_TIMEOUT, NULL);

        return 0;
}

_public_ int sd_ndisc_stop(sd_ndisc *nd) {
        assert_return(nd, -EINVAL);

        if (nd->fd < 0)
                return 0;

        log_ndisc("Stopping IPv6 Router Solicitation client");

        ndisc_reset(nd);
        return 1;
}

_public_ int sd_ndisc_start(sd_ndisc *nd) {
        int r;
        usec_t time_now;

        assert_return(nd, -EINVAL);
        assert_return(nd->event, -EINVAL);
        assert_return(nd->ifindex > 0, -EINVAL);

        if (nd->fd >= 0)
                return 0;

        assert(!nd->recv_event_source);
        assert(!nd->timeout_event_source);

        r = sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now);
        if (r < 0)
                goto fail;

        nd->fd = icmp6_bind_router_solicitation(nd->ifindex);
        if (nd->fd < 0)
                return nd->fd;

        r = sd_event_add_io(nd->event, &nd->recv_event_source, nd->fd, EPOLLIN, ndisc_recv, nd);
        if (r < 0)
                goto fail;

        r = sd_event_source_set_priority(nd->recv_event_source, nd->event_priority);
        if (r < 0)
                goto fail;

        (void) sd_event_source_set_description(nd->recv_event_source, "ndisc-receive-message");

        r = sd_event_add_time(nd->event, &nd->timeout_event_source, clock_boottime_or_monotonic(), 0, 0, ndisc_timeout, nd);
        if (r < 0)
                goto fail;

        r = sd_event_source_set_priority(nd->timeout_event_source, nd->event_priority);
        if (r < 0)
                goto fail;

        (void) sd_event_source_set_description(nd->timeout_event_source, "ndisc-timeout");

        r = sd_event_add_time(nd->event, &nd->timeout_no_ra,
                              clock_boottime_or_monotonic(),
                              time_now + NDISC_TIMEOUT_NO_RA_USEC,
                              10 * USEC_PER_MSEC, ndisc_timeout_no_ra, nd);
        if (r < 0)
                goto fail;

        r = sd_event_source_set_priority(nd->timeout_no_ra, nd->event_priority);
        if (r < 0)
                goto fail;

        (void) sd_event_source_set_description(nd->timeout_no_ra, "ndisc-timeout-no-ra");

        log_ndisc("Started IPv6 Router Solicitation client");
        return 1;

fail:
        ndisc_reset(nd);
        return r;
}
Commit	Line	Data
e3169126 PF	1	/***
	2	This file is part of systemd.
	3
	4	Copyright (C) 2014 Intel Corporation. All rights reserved.
	5
	6	systemd is free software; you can redistribute it and/or modify it
	7	under the terms of the GNU Lesser General Public License as published by
	8	the Free Software Foundation; either version 2.1 of the License, or
	9	(at your option) any later version.
	10
	11	systemd is distributed in the hope that it will be useful, but
	12	WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	Lesser General Public License for more details.
	15
	16	You should have received a copy of the GNU Lesser General Public License
	17	along with systemd; If not, see <http://www.gnu.org/licenses/>.
	18	***/
	19
	20	#include <netinet/icmp6.h>
07630cea	21	#include <netinet/in.h>
e3169126	22
07630cea LP	23	#include "sd-ndisc.h"
07630cea LP	24
b5efdb8a	25	#include "alloc-util.h"
1e7a0e21	26	#include "fd-util.h"
07630cea	27	#include "icmp6-util.h"
9d96e6c3	28	#include "in-addr-util.h"
1e7a0e21 LP	29	#include "ndisc-internal.h"
1e7a0e21 LP	30	#include "ndisc-router.h"
1bd6f895	31	#include "random-util.h"
940367a0	32	#include "socket-util.h"
d7fa4380	33	#include "string-util.h"
1e7a0e21	34	#include "util.h"
e3169126	35
1bd6f895	36	#define NDISC_TIMEOUT_NO_RA_USEC (NDISC_ROUTER_SOLICITATION_INTERVAL * NDISC_MAX_ROUTER_SOLICITATIONS)
e3169126	37
1e7a0e21 LP	38	static void ndisc_callback(sd_ndisc ndisc, sd_ndisc_event event, sd_ndisc_router rt) {
1e7a0e21 LP	39	assert(ndisc);
e3169126	40
1e7a0e21	41	log_ndisc("Invoking callback for '%c'.", event);
09667885	42
1e7a0e21 LP	43	if (!ndisc->callback)
1e7a0e21 LP	44	return;
9d96e6c3	45
1e7a0e21	46	ndisc->callback(ndisc, event, rt, ndisc->userdata);
5624c480 PF	47	}
5624c480 PF	48
1e7a0e21	49	_public_ int sd_ndisc_set_callback(
a1140666	50	sd_ndisc *nd,
a1140666 LP	51	sd_ndisc_callback_t callback,
	52	void *userdata) {
	53
	54	assert_return(nd, -EINVAL);
e3169126 PF	55
	56	nd->callback = callback;
	57	nd->userdata = userdata;
	58
	59	return 0;
	60	}
	61
1e7a0e21	62	_public_ int sd_ndisc_set_ifindex(sd_ndisc *nd, int ifindex) {
2f8e7633 LP	63	assert_return(nd, -EINVAL);
2f8e7633 LP	64	assert_return(ifindex > 0, -EINVAL);
1e7a0e21	65	assert_return(nd->fd < 0, -EBUSY);
e3169126	66
2f8e7633	67	nd->ifindex = ifindex;
e3169126 PF	68	return 0;
	69	}
	70
1e7a0e21	71	_public_ int sd_ndisc_set_mac(sd_ndisc nd, const struct ether_addr mac_addr) {
a1140666	72	assert_return(nd, -EINVAL);
e3169126 PF	73
e3169126 PF	74	if (mac_addr)
1e7a0e21	75	nd->mac_addr = *mac_addr;
e3169126	76	else
eccaf899	77	zero(nd->mac_addr);
e3169126 PF	78
e3169126 PF	79	return 0;
e3169126 PF	80	}
e3169126 PF	81
1e7a0e21	82	_public_ int sd_ndisc_attach_event(sd_ndisc nd, sd_event event, int64_t priority) {
e3169126 PF	83	int r;
	84
	85	assert_return(nd, -EINVAL);
1e7a0e21	86	assert_return(nd->fd < 0, -EBUSY);
e3169126 PF	87	assert_return(!nd->event, -EBUSY);
	88
	89	if (event)
	90	nd->event = sd_event_ref(event);
	91	else {
	92	r = sd_event_default(&nd->event);
	93	if (r < 0)
	94	return 0;
	95	}
	96
	97	nd->event_priority = priority;
	98
	99	return 0;
	100	}
	101
1e7a0e21 LP	102	_public_ int sd_ndisc_detach_event(sd_ndisc *nd) {
1e7a0e21 LP	103
e3169126	104	assert_return(nd, -EINVAL);
1e7a0e21	105	assert_return(nd->fd < 0, -EBUSY);
e3169126 PF	106
e3169126 PF	107	nd->event = sd_event_unref(nd->event);
e3169126 PF	108	return 0;
	109	}
	110
1e7a0e21	111	_public_ sd_event sd_ndisc_get_event(sd_ndisc nd) {
a1140666	112	assert_return(nd, NULL);
e3169126 PF	113
	114	return nd->event;
	115	}
	116
1e7a0e21	117	_public_ sd_ndisc sd_ndisc_ref(sd_ndisc nd) {
e3169126	118
9c8e3101 LP	119	if (!nd)
	120	return NULL;
	121
	122	assert(nd->n_ref > 0);
	123	nd->n_ref++;
e3169126 PF	124
	125	return nd;
	126	}
	127
5c4c338a	128	static int ndisc_reset(sd_ndisc *nd) {
e3169126 PF	129	assert(nd);
e3169126 PF	130
3e261cfd	131	nd->timeout_event_source = sd_event_source_unref(nd->timeout_event_source);
1bd6f895 PF	132	nd->timeout_no_ra = sd_event_source_unref(nd->timeout_no_ra);
1bd6f895 PF	133	nd->retransmit_time = 0;
1e7a0e21 LP	134	nd->recv_event_source = sd_event_source_unref(nd->recv_event_source);
1e7a0e21 LP	135	nd->fd = safe_close(nd->fd);
e3169126 PF	136
	137	return 0;
	138	}
	139
1e7a0e21	140	_public_ sd_ndisc sd_ndisc_unref(sd_ndisc nd) {
e3169126	141
9c8e3101 LP	142	if (!nd)
	143	return NULL;
	144
	145	assert(nd->n_ref > 0);
	146	nd->n_ref--;
	147
	148	if (nd->n_ref > 0)
	149	return NULL;
e3169126	150
5c4c338a	151	ndisc_reset(nd);
4d7b83da	152	sd_ndisc_detach_event(nd);
6b430fdb	153	return mfree(nd);
e3169126 PF	154	}
e3169126 PF	155
1e7a0e21	156	_public_ int sd_ndisc_new(sd_ndisc **ret) {
4afd3348	157	_cleanup_(sd_ndisc_unrefp) sd_ndisc *nd = NULL;
e3169126	158
a1140666	159	assert_return(ret, -EINVAL);
e3169126	160
4d7b83da	161	nd = new0(sd_ndisc, 1);
e3169126 PF	162	if (!nd)
	163	return -ENOMEM;
	164
9c8e3101	165	nd->n_ref = 1;
03de7ed9	166	nd->fd = -1;
e3169126 PF	167
	168	*ret = nd;
	169	nd = NULL;
	170
	171	return 0;
	172	}
	173
1e7a0e21	174	_public_ int sd_ndisc_get_mtu(sd_ndisc nd, uint32_t mtu) {
d14b5bc6 PF	175	assert_return(nd, -EINVAL);
	176	assert_return(mtu, -EINVAL);
	177
	178	if (nd->mtu == 0)
1e7a0e21	179	return -ENODATA;
d14b5bc6 PF	180
d14b5bc6 PF	181	*mtu = nd->mtu;
d14b5bc6 PF	182	return 0;
	183	}
	184
1e7a0e21 LP	185	_public_ int sd_ndisc_get_hop_limit(sd_ndisc nd, uint8_t ret) {
	186	assert_return(nd, -EINVAL);
	187	assert_return(ret, -EINVAL);
d77bde34	188
1e7a0e21 LP	189	if (nd->hop_limit == 0)
1e7a0e21 LP	190	return -ENODATA;
d77bde34	191
1e7a0e21	192	*ret = nd->hop_limit;
d77bde34 PF	193	return 0;
	194	}
	195
1e7a0e21	196	static int ndisc_handle_datagram(sd_ndisc nd, sd_ndisc_router rt) {
f6e0ce66	197	int r;
d77bde34	198
f6e0ce66	199	assert(nd);
1e7a0e21	200	assert(rt);
d77bde34	201
1e7a0e21 LP	202	r = ndisc_router_parse(rt);
1e7a0e21 LP	203	if (r == -EBADMSG) /* Bad packet */
9d96e6c3	204	return 0;
f6e0ce66	205	if (r < 0)
1e7a0e21	206	return 0;
09667885	207
1e7a0e21 LP	208	/* Update global variables we keep */
	209	if (rt->mtu > 0)
	210	nd->mtu = rt->mtu;
	211	if (rt->hop_limit > 0)
	212	nd->hop_limit = rt->hop_limit;
09667885	213
1e7a0e21 LP	214	log_ndisc("Received Router Advertisement: flags %s preference %s lifetime %" PRIu16 " sec",
	215	rt->flags & ND_RA_FLAG_MANAGED ? "MANAGED" : rt->flags & ND_RA_FLAG_OTHER ? "OTHER" : "none",
	216	rt->preference == SD_NDISC_PREFERENCE_HIGH ? "high" : rt->preference == SD_NDISC_PREFERENCE_LOW ? "low" : "medium",
	217	rt->lifetime);
09667885	218
1e7a0e21	219	ndisc_callback(nd, SD_NDISC_EVENT_ROUTER, rt);
09667885 PF	220	return 0;
	221	}
	222
1e7a0e21 LP	223	static int ndisc_recv(sd_event_source s, int fd, uint32_t revents, void userdata) {
1e7a0e21 LP	224	_cleanup_(sd_ndisc_router_unrefp) sd_ndisc_router *rt = NULL;
4d7b83da	225	sd_ndisc *nd = userdata;
88d5a3db PF	226	ssize_t buflen;
	227	int r;
	228	_cleanup_free_ char *addr = NULL;
e3169126 PF	229
	230	assert(s);
	231	assert(nd);
	232	assert(nd->event);
	233
4edc2c9b LP	234	buflen = next_datagram_size_fd(fd);
4edc2c9b LP	235	if (buflen < 0)
1e7a0e21	236	return log_ndisc_errno(buflen, "Failed to determine datagram size to read: %m");
cddf4d81	237
1e7a0e21 LP	238	rt = ndisc_router_new(buflen);
1e7a0e21 LP	239	if (!rt)
09667885 PF	240	return -ENOMEM;
09667885 PF	241
88d5a3db PF	242	r = icmp6_receive(fd, NDISC_ROUTER_RAW(rt), rt->raw_size, &rt->address,
	243	&rt->timestamp);
	244	if (r < 0) {
	245	switch (r) {
	246	case -EADDRNOTAVAIL:
	247	(void) in_addr_to_string(AF_INET6, (union in_addr_union*) &rt->address, &addr);
	248	log_ndisc("Received RA from non-link-local address %s. Ignoring", addr);
	249	break;
	250
	251	case -EMULTIHOP:
	252	log_ndisc("Received RA with invalid hop limit. Ignoring.");
	253	break;
	254
	255	case -EPFNOSUPPORT:
	256	log_ndisc("Received invalid source address from ICMPv6 socket.");
	257	break;
1e7a0e21 LP	258	}
1e7a0e21 LP	259
88d5a3db	260	return 0;
d7fa4380	261	}
3ccd3163	262
3e261cfd	263	nd->timeout_event_source = sd_event_source_unref(nd->timeout_event_source);
09667885	264
1e7a0e21	265	return ndisc_handle_datagram(nd, rt);
e3169126 PF	266	}
e3169126 PF	267
1bd6f895 PF	268	static usec_t ndisc_timeout_compute_random(usec_t val) {
	269	/* compute a time that is random within ±10% of the given value */
	270	return val - val / 10 +
	271	(random_u64() % (2 * USEC_PER_SEC)) * val / 10 / USEC_PER_SEC;
	272	}
	273
1e7a0e21	274	static int ndisc_timeout(sd_event_source s, uint64_t usec, void userdata) {
4d7b83da	275	sd_ndisc *nd = userdata;
1bd6f895	276	usec_t time_now;
e3169126	277	int r;
1bd6f895	278	char time_string[FORMAT_TIMESPAN_MAX];
e3169126 PF	279
	280	assert(s);
	281	assert(nd);
	282	assert(nd->event);
	283
1e7a0e21 LP	284	r = icmp6_send_router_solicitation(nd->fd, &nd->mac_addr);
	285	if (r < 0) {
	286	log_ndisc_errno(r, "Error sending Router Solicitation: %m");
	287	goto fail;
	288	}
e3169126	289
1e7a0e21	290	assert_se(sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now) >= 0);
e3169126	291
1bd6f895 PF	292	nd->timeout_event_source = sd_event_source_unref(nd->timeout_event_source);
	293
	294	if (!nd->retransmit_time)
	295	nd->retransmit_time = ndisc_timeout_compute_random(NDISC_ROUTER_SOLICITATION_INTERVAL);
	296	else {
	297	if (nd->retransmit_time > NDISC_MAX_ROUTER_SOLICITATION_INTERVAL / 2)
	298	nd->retransmit_time = ndisc_timeout_compute_random(NDISC_MAX_ROUTER_SOLICITATION_INTERVAL);
	299	else
	300	nd->retransmit_time += ndisc_timeout_compute_random(nd->retransmit_time);
1e7a0e21	301	}
9021bb9f	302
1bd6f895 PF	303	r = sd_event_add_time(nd->event, &nd->timeout_event_source,
	304	clock_boottime_or_monotonic(),
	305	time_now + nd->retransmit_time,
	306	10 * USEC_PER_MSEC, ndisc_timeout, nd);
	307	if (r < 0)
	308	goto fail;
	309
	310	r = sd_event_source_set_priority(nd->timeout_event_source, nd->event_priority);
	311	if (r < 0)
	312	goto fail;
	313
	314	(void) sd_event_source_set_description(nd->timeout_event_source, "ndisc-timeout-no-ra");
	315
1e7a0e21 LP	316	r = sd_event_source_set_enabled(nd->timeout_event_source, SD_EVENT_ONESHOT);
	317	if (r < 0) {
	318	log_ndisc_errno(r, "Error reenabling timer: %m");
	319	goto fail;
e3169126 PF	320	}
e3169126 PF	321
1bd6f895 PF	322	log_ndisc("Sent Router Solicitation, next solicitation in %s",
	323	format_timespan(time_string, FORMAT_TIMESPAN_MAX,
	324	nd->retransmit_time, USEC_PER_SEC));
	325
e3169126	326	return 0;
b9e7b1cf LP	327
	328	fail:
	329	sd_ndisc_stop(nd);
	330	return 0;
e3169126 PF	331	}
e3169126 PF	332
1bd6f895 PF	333	static int ndisc_timeout_no_ra(sd_event_source s, uint64_t usec, void userdata) {
	334	sd_ndisc *nd = userdata;
	335
	336	assert(s);
	337	assert(nd);
	338
	339	log_ndisc("No RA received before link confirmation timeout");
	340
	341	nd->timeout_no_ra = sd_event_source_unref(nd->timeout_no_ra);
	342	ndisc_callback(nd, SD_NDISC_EVENT_TIMEOUT, NULL);
	343
	344	return 0;
	345	}
	346
1e7a0e21	347	_public_ int sd_ndisc_stop(sd_ndisc *nd) {
836cf090	348	assert_return(nd, -EINVAL);
836cf090	349
1e7a0e21	350	if (nd->fd < 0)
c1c9b211 LP	351	return 0;
c1c9b211 LP	352
1e7a0e21	353	log_ndisc("Stopping IPv6 Router Solicitation client");
836cf090	354
5c4c338a	355	ndisc_reset(nd);
1e7a0e21	356	return 1;
836cf090 PF	357	}
836cf090 PF	358
1e7a0e21	359	_public_ int sd_ndisc_start(sd_ndisc *nd) {
e3169126	360	int r;
1bd6f895	361	usec_t time_now;
e3169126	362
a1140666 LP	363	assert_return(nd, -EINVAL);
	364	assert_return(nd->event, -EINVAL);
	365	assert_return(nd->ifindex > 0, -EINVAL);
e3169126	366
1e7a0e21 LP	367	if (nd->fd >= 0)
1e7a0e21 LP	368	return 0;
e3169126	369
1e7a0e21 LP	370	assert(!nd->recv_event_source);
1e7a0e21 LP	371	assert(!nd->timeout_event_source);
e3169126	372
1bd6f895 PF	373	r = sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now);
	374	if (r < 0)
	375	goto fail;
	376
1e7a0e21 LP	377	nd->fd = icmp6_bind_router_solicitation(nd->ifindex);
	378	if (nd->fd < 0)
	379	return nd->fd;
	380
	381	r = sd_event_add_io(nd->event, &nd->recv_event_source, nd->fd, EPOLLIN, ndisc_recv, nd);
e3169126	382	if (r < 0)
5c4c338a	383	goto fail;
e3169126	384
3e261cfd	385	r = sd_event_source_set_priority(nd->recv_event_source, nd->event_priority);
e3169126	386	if (r < 0)
5c4c338a	387	goto fail;
e3169126	388
3e261cfd	389	(void) sd_event_source_set_description(nd->recv_event_source, "ndisc-receive-message");
9021bb9f	390
1e7a0e21	391	r = sd_event_add_time(nd->event, &nd->timeout_event_source, clock_boottime_or_monotonic(), 0, 0, ndisc_timeout, nd);
e3169126	392	if (r < 0)
5c4c338a	393	goto fail;
e3169126	394
3e261cfd	395	r = sd_event_source_set_priority(nd->timeout_event_source, nd->event_priority);
9021bb9f	396	if (r < 0)
5c4c338a	397	goto fail;
e3169126	398
3e261cfd	399	(void) sd_event_source_set_description(nd->timeout_event_source, "ndisc-timeout");
5c4c338a	400
1bd6f895 PF	401	r = sd_event_add_time(nd->event, &nd->timeout_no_ra,
	402	clock_boottime_or_monotonic(),
	403	time_now + NDISC_TIMEOUT_NO_RA_USEC,
	404	10 * USEC_PER_MSEC, ndisc_timeout_no_ra, nd);
	405	if (r < 0)
	406	goto fail;
	407
	408	r = sd_event_source_set_priority(nd->timeout_no_ra, nd->event_priority);
	409	if (r < 0)
	410	goto fail;
	411
	412	(void) sd_event_source_set_description(nd->timeout_no_ra, "ndisc-timeout-no-ra");
	413
1e7a0e21 LP	414	log_ndisc("Started IPv6 Router Solicitation client");
1e7a0e21 LP	415	return 1;
e3169126	416
5c4c338a LP	417	fail:
5c4c338a LP	418	ndisc_reset(nd);
e3169126 PF	419	return r;
e3169126 PF	420	}