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systemd/src/libsystemd-network/sd-radv.c
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Lennart Poettering bd1ae17833 io-util: split out "struct iovec" related calls into their own .c/.h files 
This is preparation for #28891, which adds a bunch more helpers around
"struct iovec", at which point this really deserves its own .c/.h file.

The idea is that we sooner or later can consider "struct iovec" as an
entirely generic mechanism to reference some binary blob, and is the
go-to type for this purpose whenever we need one.
2023-10-20 10:34:33 +02:00

1162 lines
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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/***
Copyright © 2017 Intel Corporation. All rights reserved.
***/
#include <netinet/icmp6.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "sd-radv.h"
#include "alloc-util.h"
#include "dns-domain.h"
#include "ether-addr-util.h"
#include "event-util.h"
#include "fd-util.h"
#include "icmp6-util.h"
#include "in-addr-util.h"
#include "iovec-util.h"
#include "macro.h"
#include "memory-util.h"
#include "network-common.h"
#include "radv-internal.h"
#include "random-util.h"
#include "socket-util.h"
#include "string-util.h"
#include "strv.h"
#include "unaligned.h"
int sd_radv_new(sd_radv **ret) {
_cleanup_(sd_radv_unrefp) sd_radv *ra = NULL;
assert_return(ret, -EINVAL);
ra = new(sd_radv, 1);
if (!ra)
return -ENOMEM;
*ra = (sd_radv) {
.n_ref = 1,
.fd = -EBADF,
.lifetime_usec = RADV_DEFAULT_ROUTER_LIFETIME_USEC,
};
*ret = TAKE_PTR(ra);
return 0;
}
int sd_radv_attach_event(sd_radv *ra, sd_event *event, int64_t priority) {
int r;
assert_return(ra, -EINVAL);
assert_return(!ra->event, -EBUSY);
if (event)
ra->event = sd_event_ref(event);
else {
r = sd_event_default(&ra->event);
if (r < 0)
return 0;
}
ra->event_priority = priority;
return 0;
}
int sd_radv_detach_event(sd_radv *ra) {
assert_return(ra, -EINVAL);
ra->event = sd_event_unref(ra->event);
return 0;
}
sd_event *sd_radv_get_event(sd_radv *ra) {
assert_return(ra, NULL);
return ra->event;
}
int sd_radv_is_running(sd_radv *ra) {
assert_return(ra, false);
return ra->state != RADV_STATE_IDLE;
}
static void radv_reset(sd_radv *ra) {
assert(ra);
(void) event_source_disable(ra->timeout_event_source);
ra->recv_event_source = sd_event_source_disable_unref(ra->recv_event_source);
ra->ra_sent = 0;
}
static sd_radv *radv_free(sd_radv *ra) {
if (!ra)
return NULL;
LIST_CLEAR(prefix, ra->prefixes, sd_radv_prefix_unref);
LIST_CLEAR(prefix, ra->route_prefixes, sd_radv_route_prefix_unref);
LIST_CLEAR(prefix, ra->pref64_prefixes, sd_radv_pref64_prefix_unref);
free(ra->rdnss);
free(ra->dnssl);
radv_reset(ra);
sd_event_source_unref(ra->timeout_event_source);
sd_radv_detach_event(ra);
ra->fd = safe_close(ra->fd);
free(ra->ifname);
return mfree(ra);
}
DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv, sd_radv, radv_free);
static bool router_lifetime_is_valid(usec_t lifetime_usec) {
return lifetime_usec == 0 ||
(lifetime_usec >= RADV_MIN_ROUTER_LIFETIME_USEC &&
lifetime_usec <= RADV_MAX_ROUTER_LIFETIME_USEC);
}
static int radv_send(sd_radv *ra, const struct in6_addr *dst, usec_t lifetime_usec) {
struct sockaddr_in6 dst_addr = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
};
struct nd_router_advert adv = {};
struct {
struct nd_opt_hdr opthdr;
struct ether_addr slladdr;
} _packed_ opt_mac = {
.opthdr = {
.nd_opt_type = ND_OPT_SOURCE_LINKADDR,
.nd_opt_len = (sizeof(struct nd_opt_hdr) +
sizeof(struct ether_addr) - 1) /8 + 1,
},
};
struct nd_opt_mtu opt_mtu = {
.nd_opt_mtu_type = ND_OPT_MTU,
.nd_opt_mtu_len = 1,
};
/* Reserve iov space for RA header, linkaddr, MTU, N prefixes, N routes, RDNSS
and DNSSL */
struct iovec iov[5 + ra->n_prefixes + ra->n_route_prefixes];
struct msghdr msg = {
.msg_name = &dst_addr,
.msg_namelen = sizeof(dst_addr),
.msg_iov = iov,
};
usec_t time_now;
int r;
assert(ra);
assert(router_lifetime_is_valid(lifetime_usec));
r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
if (r < 0)
return r;
if (dst && in6_addr_is_set(dst))
dst_addr.sin6_addr = *dst;
adv.nd_ra_type = ND_ROUTER_ADVERT;
adv.nd_ra_curhoplimit = ra->hop_limit;
adv.nd_ra_retransmit = usec_to_be32_msec(ra->retransmit_usec);
adv.nd_ra_flags_reserved = ra->flags;
assert_cc(RADV_MAX_ROUTER_LIFETIME_USEC <= UINT16_MAX * USEC_PER_SEC);
adv.nd_ra_router_lifetime = usec_to_be16_sec(lifetime_usec);
iov[msg.msg_iovlen++] = IOVEC_MAKE(&adv, sizeof(adv));
/* MAC address is optional, either because the link does not use L2
addresses or load sharing is desired. See RFC 4861, Section 4.2 */
if (!ether_addr_is_null(&ra->mac_addr)) {
opt_mac.slladdr = ra->mac_addr;
iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mac, sizeof(opt_mac));
}
if (ra->mtu > 0) {
opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mtu, sizeof(opt_mtu));
}
LIST_FOREACH(prefix, p, ra->prefixes) {
usec_t lifetime_valid_usec, lifetime_preferred_usec;
lifetime_valid_usec = MIN(usec_sub_unsigned(p->valid_until, time_now),
p->lifetime_valid_usec);
lifetime_preferred_usec = MIN3(usec_sub_unsigned(p->preferred_until, time_now),
p->lifetime_preferred_usec,
lifetime_valid_usec);
p->opt.lifetime_valid = usec_to_be32_sec(lifetime_valid_usec);
p->opt.lifetime_preferred = usec_to_be32_sec(lifetime_preferred_usec);
iov[msg.msg_iovlen++] = IOVEC_MAKE(&p->opt, sizeof(p->opt));
}
LIST_FOREACH(prefix, rt, ra->route_prefixes) {
rt->opt.lifetime = usec_to_be32_sec(MIN(usec_sub_unsigned(rt->valid_until, time_now),
rt->lifetime_usec));
iov[msg.msg_iovlen++] = IOVEC_MAKE(&rt->opt, sizeof(rt->opt));
}
LIST_FOREACH(prefix, p, ra->pref64_prefixes)
iov[msg.msg_iovlen++] = IOVEC_MAKE(&p->opt, sizeof(p->opt));
if (ra->rdnss)
iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->rdnss, ra->rdnss->length * 8);
if (ra->dnssl)
iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->dnssl, ra->dnssl->length * 8);
if (FLAGS_SET(ra->flags, ND_RA_FLAG_HOME_AGENT)) {
ra->home_agent.nd_opt_home_agent_info_type = ND_OPT_HOME_AGENT_INFO;
ra->home_agent.nd_opt_home_agent_info_len = 1;
/* 0 means to place the current Router Lifetime value */
if (ra->home_agent.nd_opt_home_agent_info_lifetime == 0)
ra->home_agent.nd_opt_home_agent_info_lifetime = adv.nd_ra_router_lifetime;
iov[msg.msg_iovlen++] = IOVEC_MAKE(&ra->home_agent, sizeof(ra->home_agent));
}
if (sendmsg(ra->fd, &msg, 0) < 0)
return -errno;
return 0;
}
static int radv_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
sd_radv *ra = ASSERT_PTR(userdata);
struct in6_addr src;
triple_timestamp timestamp;
int r;
assert(s);
assert(ra->event);
ssize_t buflen = next_datagram_size_fd(fd);
if (ERRNO_IS_NEG_TRANSIENT(buflen) || ERRNO_IS_NEG_DISCONNECT(buflen))
return 0;
if (buflen < 0) {
log_radv_errno(ra, buflen, "Failed to determine datagram size to read, ignoring: %m");
return 0;
}
_cleanup_free_ char *buf = new0(char, buflen);
if (!buf)
return -ENOMEM;
r = icmp6_receive(fd, buf, buflen, &src, &timestamp);
if (ERRNO_IS_NEG_TRANSIENT(r) || ERRNO_IS_NEG_DISCONNECT(r))
return 0;
if (r < 0)
switch (r) {
case -EADDRNOTAVAIL:
log_radv(ra, "Received RS from neither link-local nor null address. Ignoring");
return 0;
case -EMULTIHOP:
log_radv(ra, "Received RS with invalid hop limit. Ignoring.");
return 0;
case -EPFNOSUPPORT:
log_radv(ra, "Received invalid source address from ICMPv6 socket. Ignoring.");
return 0;
default:
log_radv_errno(ra, r, "Unexpected error receiving from ICMPv6 socket, ignoring: %m");
return 0;
}
if ((size_t) buflen < sizeof(struct nd_router_solicit)) {
log_radv(ra, "Too short packet received, ignoring");
return 0;
}
/* TODO: if the sender address is null, check that the message does not have the source link-layer
* address option. See RFC 4861 Section 6.1.1. */
const char *addr = IN6_ADDR_TO_STRING(&src);
r = radv_send(ra, &src, ra->lifetime_usec);
if (r < 0)
log_radv_errno(ra, r, "Unable to send solicited Router Advertisement to %s, ignoring: %m", addr);
else
log_radv(ra, "Sent solicited Router Advertisement to %s", addr);
return 0;
}
static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
usec_t min_timeout, max_timeout, time_now, timeout;
sd_radv *ra = ASSERT_PTR(userdata);
int r;
assert(s);
assert(ra->event);
assert(router_lifetime_is_valid(ra->lifetime_usec));
r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
if (r < 0)
goto fail;
r = radv_send(ra, NULL, ra->lifetime_usec);
if (r < 0)
log_radv_errno(ra, r, "Unable to send Router Advertisement, ignoring: %m");
/* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
if (ra->ra_sent < RADV_MAX_INITIAL_RTR_ADVERTISEMENTS)
max_timeout = RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
else
max_timeout = RADV_DEFAULT_MAX_TIMEOUT_USEC;
/* RFC 4861, Section 6.2.1, lifetime must be at least MaxRtrAdvInterval,
* so lower the interval here */
if (ra->lifetime_usec > 0)
max_timeout = MIN(max_timeout, ra->lifetime_usec);
if (max_timeout >= 9 * USEC_PER_SEC)
min_timeout = max_timeout / 3;
else
min_timeout = max_timeout * 3 / 4;
/* RFC 4861, Section 6.2.1.
* MaxRtrAdvInterval MUST be no less than 4 seconds and no greater than 1800 seconds.
* MinRtrAdvInterval MUST be no less than 3 seconds and no greater than .75 * MaxRtrAdvInterval. */
assert(max_timeout >= RADV_MIN_MAX_TIMEOUT_USEC);
assert(max_timeout <= RADV_MAX_MAX_TIMEOUT_USEC);
assert(min_timeout >= RADV_MIN_MIN_TIMEOUT_USEC);
assert(min_timeout <= max_timeout * 3 / 4);
timeout = min_timeout + random_u64_range(max_timeout - min_timeout);
log_radv(ra, "Next Router Advertisement in %s", FORMAT_TIMESPAN(timeout, USEC_PER_SEC));
r = event_reset_time(ra->event, &ra->timeout_event_source,
CLOCK_BOOTTIME,
usec_add(time_now, timeout), MSEC_PER_SEC,
radv_timeout, ra,
ra->event_priority, "radv-timeout", true);
if (r < 0)
goto fail;
ra->ra_sent++;
return 0;
fail:
sd_radv_stop(ra);
return 0;
}
int sd_radv_stop(sd_radv *ra) {
int r;
if (!ra)
return 0;
if (ra->state == RADV_STATE_IDLE)
return 0;
log_radv(ra, "Stopping IPv6 Router Advertisement daemon");
/* RFC 4861, Section 6.2.5, send at least one Router Advertisement
with zero lifetime */
r = radv_send(ra, NULL, 0);
if (r < 0)
log_radv_errno(ra, r, "Unable to send last Router Advertisement with router lifetime set to zero, ignoring: %m");
radv_reset(ra);
ra->fd = safe_close(ra->fd);
ra->state = RADV_STATE_IDLE;
return 0;
}
int sd_radv_start(sd_radv *ra) {
int r;
assert_return(ra, -EINVAL);
assert_return(ra->event, -EINVAL);
assert_return(ra->ifindex > 0, -EINVAL);
if (ra->state != RADV_STATE_IDLE)
return 0;
r = event_reset_time(ra->event, &ra->timeout_event_source,
CLOCK_BOOTTIME,
0, 0,
radv_timeout, ra,
ra->event_priority, "radv-timeout", true);
if (r < 0)
goto fail;
r = icmp6_bind_router_advertisement(ra->ifindex);
if (r < 0)
goto fail;
ra->fd = r;
r = sd_event_add_io(ra->event, &ra->recv_event_source, ra->fd, EPOLLIN, radv_recv, ra);
if (r < 0)
goto fail;
r = sd_event_source_set_priority(ra->recv_event_source, ra->event_priority);
if (r < 0)
goto fail;
(void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");
ra->state = RADV_STATE_ADVERTISING;
log_radv(ra, "Started IPv6 Router Advertisement daemon");
return 0;
fail:
radv_reset(ra);
return r;
}
int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
assert_return(ra, -EINVAL);
assert_return(ifindex > 0, -EINVAL);
if (ra->state != RADV_STATE_IDLE)
return -EBUSY;
ra->ifindex = ifindex;
return 0;
}
int sd_radv_set_ifname(sd_radv *ra, const char *ifname) {
assert_return(ra, -EINVAL);
assert_return(ifname, -EINVAL);
if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE))
return -EINVAL;
return free_and_strdup(&ra->ifname, ifname);
}
int sd_radv_get_ifname(sd_radv *ra, const char **ret) {
int r;
assert_return(ra, -EINVAL);
r = get_ifname(ra->ifindex, &ra->ifname);
if (r < 0)
return r;
if (ret)
*ret = ra->ifname;
return 0;
}
int sd_radv_set_mac(sd_radv *ra, const struct ether_addr *mac_addr) {
assert_return(ra, -EINVAL);
if (ra->state != RADV_STATE_IDLE)
return -EBUSY;
if (mac_addr)
ra->mac_addr = *mac_addr;
else
zero(ra->mac_addr);
return 0;
}
int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
assert_return(ra, -EINVAL);
assert_return(mtu >= 1280, -EINVAL);
ra->mtu = mtu;
return 0;
}
int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
assert_return(ra, -EINVAL);
if (ra->state != RADV_STATE_IDLE)
return -EBUSY;
ra->hop_limit = hop_limit;
return 0;
}
int sd_radv_set_retransmit(sd_radv *ra, uint64_t usec) {
assert_return(ra, -EINVAL);
if (ra->state != RADV_STATE_IDLE)
return -EBUSY;
if (usec > RADV_MAX_RETRANSMIT_USEC)
return -EINVAL;
ra->retransmit_usec = usec;
return 0;
}
int sd_radv_set_router_lifetime(sd_radv *ra, uint64_t usec) {
assert_return(ra, -EINVAL);
if (ra->state != RADV_STATE_IDLE)
return -EBUSY;
if (!router_lifetime_is_valid(usec))
return -EINVAL;
/* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the preference value MUST be set
* to (00) by the sender..." */
if (usec == 0 &&
(ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
return -EINVAL;
ra->lifetime_usec = usec;
return 0;
}
int sd_radv_set_managed_information(sd_radv *ra, int managed) {
assert_return(ra, -EINVAL);
if (ra->state != RADV_STATE_IDLE)
return -EBUSY;
SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);
return 0;
}
int sd_radv_set_other_information(sd_radv *ra, int other) {
assert_return(ra, -EINVAL);
if (ra->state != RADV_STATE_IDLE)
return -EBUSY;
SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);
return 0;
}
int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
assert_return(ra, -EINVAL);
assert_return(IN_SET(preference,
SD_NDISC_PREFERENCE_LOW,
SD_NDISC_PREFERENCE_MEDIUM,
SD_NDISC_PREFERENCE_HIGH), -EINVAL);
/* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the preference value MUST be set
* to (00) by the sender..." */
if (ra->lifetime_usec == 0 && preference != SD_NDISC_PREFERENCE_MEDIUM)
return -EINVAL;
ra->flags = (ra->flags & ~(0x3 << 3)) | (preference << 3);
return 0;
}
int sd_radv_set_home_agent_information(sd_radv *ra, int home_agent) {
assert_return(ra, -EINVAL);
if (ra->state != RADV_STATE_IDLE)
return -EBUSY;
SET_FLAG(ra->flags, ND_RA_FLAG_HOME_AGENT, home_agent);
return 0;
}
int sd_radv_set_home_agent_preference(sd_radv *ra, uint16_t preference) {
assert_return(ra, -EINVAL);
if (ra->state != RADV_STATE_IDLE)
return -EBUSY;
ra->home_agent.nd_opt_home_agent_info_preference = htobe16(preference);
return 0;
}
int sd_radv_set_home_agent_lifetime(sd_radv *ra, uint64_t lifetime_usec) {
assert_return(ra, -EINVAL);
if (ra->state != RADV_STATE_IDLE)
return -EBUSY;
if (lifetime_usec > RADV_HOME_AGENT_MAX_LIFETIME_USEC)
return -EINVAL;
ra->home_agent.nd_opt_home_agent_info_lifetime = usec_to_be16_sec(lifetime_usec);
return 0;
}
int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p) {
sd_radv_prefix *found = NULL;
int r;
assert_return(ra, -EINVAL);
assert_return(p, -EINVAL);
/* Refuse prefixes that don't have a prefix set */
if (in6_addr_is_null(&p->opt.in6_addr))
return -ENOEXEC;
const char *addr_p = IN6_ADDR_PREFIX_TO_STRING(&p->opt.in6_addr, p->opt.prefixlen);
LIST_FOREACH(prefix, cur, ra->prefixes) {
r = in_addr_prefix_intersect(AF_INET6,
(const union in_addr_union*) &cur->opt.in6_addr,
cur->opt.prefixlen,
(const union in_addr_union*) &p->opt.in6_addr,
p->opt.prefixlen);
if (r < 0)
return r;
if (r == 0)
continue;
if (cur->opt.prefixlen == p->opt.prefixlen) {
found = cur;
break;
}
return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
"IPv6 prefix %s conflicts with %s, ignoring.",
addr_p,
IN6_ADDR_PREFIX_TO_STRING(&cur->opt.in6_addr, cur->opt.prefixlen));
}
if (found) {
/* p and cur may be equivalent. First increment the reference counter. */
sd_radv_prefix_ref(p);
/* Then, remove the old entry. */
LIST_REMOVE(prefix, ra->prefixes, found);
sd_radv_prefix_unref(found);
/* Finally, add the new entry. */
LIST_APPEND(prefix, ra->prefixes, p);
log_radv(ra, "Updated/replaced IPv6 prefix %s (preferred: %s, valid: %s)",
addr_p,
FORMAT_TIMESPAN(p->lifetime_preferred_usec, USEC_PER_SEC),
FORMAT_TIMESPAN(p->lifetime_valid_usec, USEC_PER_SEC));
} else {
/* The prefix is new. Let's simply add it. */
sd_radv_prefix_ref(p);
LIST_APPEND(prefix, ra->prefixes, p);
ra->n_prefixes++;
log_radv(ra, "Added prefix %s", addr_p);
}
if (ra->state == RADV_STATE_IDLE)
return 0;
if (ra->ra_sent == 0)
return 0;
/* If RAs have already been sent, send an RA immediately to announce the newly-added prefix */
r = radv_send(ra, NULL, ra->lifetime_usec);
if (r < 0)
log_radv_errno(ra, r, "Unable to send Router Advertisement for added prefix %s, ignoring: %m", addr_p);
else
log_radv(ra, "Sent Router Advertisement for added/updated prefix %s.", addr_p);
return 0;
}
void sd_radv_remove_prefix(
sd_radv *ra,
const struct in6_addr *prefix,
unsigned char prefixlen) {
if (!ra)
return;
if (!prefix)
return;
LIST_FOREACH(prefix, cur, ra->prefixes) {
if (prefixlen != cur->opt.prefixlen)
continue;
if (!in6_addr_equal(prefix, &cur->opt.in6_addr))
continue;
LIST_REMOVE(prefix, ra->prefixes, cur);
ra->n_prefixes--;
sd_radv_prefix_unref(cur);
return;
}
}
int sd_radv_add_route_prefix(sd_radv *ra, sd_radv_route_prefix *p) {
sd_radv_route_prefix *found = NULL;
int r;
assert_return(ra, -EINVAL);
assert_return(p, -EINVAL);
const char *addr_p = IN6_ADDR_PREFIX_TO_STRING(&p->opt.in6_addr, p->opt.prefixlen);
LIST_FOREACH(prefix, cur, ra->route_prefixes) {
r = in_addr_prefix_intersect(AF_INET6,
(const union in_addr_union*) &cur->opt.in6_addr,
cur->opt.prefixlen,
(const union in_addr_union*) &p->opt.in6_addr,
p->opt.prefixlen);
if (r < 0)
return r;
if (r == 0)
continue;
if (cur->opt.prefixlen == p->opt.prefixlen) {
found = cur;
break;
}
return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
"IPv6 route prefix %s conflicts with %s, ignoring.",
addr_p,
IN6_ADDR_PREFIX_TO_STRING(&cur->opt.in6_addr, cur->opt.prefixlen));
}
if (found) {
/* p and cur may be equivalent. First increment the reference counter. */
sd_radv_route_prefix_ref(p);
/* Then, remove the old entry. */
LIST_REMOVE(prefix, ra->route_prefixes, found);
sd_radv_route_prefix_unref(found);
/* Finally, add the new entry. */
LIST_APPEND(prefix, ra->route_prefixes, p);
log_radv(ra, "Updated/replaced IPv6 route prefix %s (lifetime: %s)",
strna(addr_p),
FORMAT_TIMESPAN(p->lifetime_usec, USEC_PER_SEC));
} else {
/* The route prefix is new. Let's simply add it. */
sd_radv_route_prefix_ref(p);
LIST_APPEND(prefix, ra->route_prefixes, p);
ra->n_route_prefixes++;
log_radv(ra, "Added route prefix %s", strna(addr_p));
}
if (ra->state == RADV_STATE_IDLE)
return 0;
if (ra->ra_sent == 0)
return 0;
/* If RAs have already been sent, send an RA immediately to announce the newly-added route prefix */
r = radv_send(ra, NULL, ra->lifetime_usec);
if (r < 0)
log_radv_errno(ra, r, "Unable to send Router Advertisement for added route prefix %s, ignoring: %m",
strna(addr_p));
else
log_radv(ra, "Sent Router Advertisement for added route prefix %s.", strna(addr_p));
return 0;
}
int sd_radv_add_pref64_prefix(sd_radv *ra, sd_radv_pref64_prefix *p) {
sd_radv_pref64_prefix *found = NULL;
int r;
assert_return(ra, -EINVAL);
assert_return(p, -EINVAL);
const char *addr_p = IN6_ADDR_PREFIX_TO_STRING(&p->in6_addr, p->prefixlen);
LIST_FOREACH(prefix, cur, ra->pref64_prefixes) {
r = in_addr_prefix_intersect(AF_INET6,
(const union in_addr_union*) &cur->in6_addr,
cur->prefixlen,
(const union in_addr_union*) &p->in6_addr,
p->prefixlen);
if (r < 0)
return r;
if (r == 0)
continue;
if (cur->prefixlen == p->prefixlen) {
found = cur;
break;
}
return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
"IPv6 PREF64 prefix %s conflicts with %s, ignoring.",
addr_p,
IN6_ADDR_PREFIX_TO_STRING(&cur->in6_addr, cur->prefixlen));
}
if (found) {
/* p and cur may be equivalent. First increment the reference counter. */
sd_radv_pref64_prefix_ref(p);
/* Then, remove the old entry. */
LIST_REMOVE(prefix, ra->pref64_prefixes, found);
sd_radv_pref64_prefix_unref(found);
/* Finally, add the new entry. */
LIST_APPEND(prefix, ra->pref64_prefixes, p);
log_radv(ra, "Updated/replaced IPv6 PREF64 prefix %s (lifetime: %s)",
strna(addr_p),
FORMAT_TIMESPAN(p->lifetime_usec, USEC_PER_SEC));
} else {
/* The route prefix is new. Let's simply add it. */
sd_radv_pref64_prefix_ref(p);
LIST_APPEND(prefix, ra->pref64_prefixes, p);
ra->n_pref64_prefixes++;
log_radv(ra, "Added PREF64 prefix %s", strna(addr_p));
}
if (ra->state == RADV_STATE_IDLE)
return 0;
if (ra->ra_sent == 0)
return 0;
/* If RAs have already been sent, send an RA immediately to announce the newly-added route prefix */
r = radv_send(ra, NULL, ra->lifetime_usec);
if (r < 0)
log_radv_errno(ra, r, "Unable to send Router Advertisement for added PREF64 prefix %s, ignoring: %m",
strna(addr_p));
else
log_radv(ra, "Sent Router Advertisement for added PREF64 prefix %s.", strna(addr_p));
return 0;
}
int sd_radv_set_rdnss(
sd_radv *ra,
uint64_t lifetime_usec,
const struct in6_addr *dns,
size_t n_dns) {
_cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
size_t len;
assert_return(ra, -EINVAL);
assert_return(n_dns < 128, -EINVAL);
if (lifetime_usec > RADV_RDNSS_MAX_LIFETIME_USEC)
return -EINVAL;
if (!dns || n_dns == 0) {
ra->rdnss = mfree(ra->rdnss);
ra->n_rdnss = 0;
return 0;
}
len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;
opt_rdnss = malloc0(len);
if (!opt_rdnss)
return -ENOMEM;
opt_rdnss->type = RADV_OPT_RDNSS;
opt_rdnss->length = len / 8;
opt_rdnss->lifetime = usec_to_be32_sec(lifetime_usec);
memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));
free_and_replace(ra->rdnss, opt_rdnss);
ra->n_rdnss = n_dns;
return 0;
}
int sd_radv_set_dnssl(
sd_radv *ra,
uint64_t lifetime_usec,
char **search_list) {
_cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
size_t len = 0;
uint8_t *p;
assert_return(ra, -EINVAL);
if (lifetime_usec > RADV_DNSSL_MAX_LIFETIME_USEC)
return -EINVAL;
if (strv_isempty(search_list)) {
ra->dnssl = mfree(ra->dnssl);
return 0;
}
STRV_FOREACH(s, search_list)
len += strlen(*s) + 2;
len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;
opt_dnssl = malloc0(len);
if (!opt_dnssl)
return -ENOMEM;
opt_dnssl->type = RADV_OPT_DNSSL;
opt_dnssl->length = len / 8;
opt_dnssl->lifetime = usec_to_be32_sec(lifetime_usec);
p = (uint8_t *)(opt_dnssl + 1);
len -= sizeof(struct sd_radv_opt_dns);
STRV_FOREACH(s, search_list) {
int r;
r = dns_name_to_wire_format(*s, p, len, false);
if (r < 0)
return r;
if (len < (size_t)r)
return -ENOBUFS;
p += r;
len -= r;
}
free_and_replace(ra->dnssl, opt_dnssl);
return 0;
}
int sd_radv_prefix_new(sd_radv_prefix **ret) {
sd_radv_prefix *p;
assert_return(ret, -EINVAL);
p = new(sd_radv_prefix, 1);
if (!p)
return -ENOMEM;
*p = (sd_radv_prefix) {
.n_ref = 1,
.opt.type = ND_OPT_PREFIX_INFORMATION,
.opt.length = (sizeof(p->opt) - 1)/8 + 1,
.opt.prefixlen = 64,
/* RFC 4861, Section 6.2.1 */
.opt.flags = ND_OPT_PI_FLAG_ONLINK|ND_OPT_PI_FLAG_AUTO,
.lifetime_valid_usec = RADV_DEFAULT_VALID_LIFETIME_USEC,
.lifetime_preferred_usec = RADV_DEFAULT_PREFERRED_LIFETIME_USEC,
.valid_until = USEC_INFINITY,
.preferred_until = USEC_INFINITY,
};
*ret = p;
return 0;
}
DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_prefix, sd_radv_prefix, mfree);
int sd_radv_prefix_set_prefix(
sd_radv_prefix *p,
const struct in6_addr *in6_addr,
unsigned char prefixlen) {
assert_return(p, -EINVAL);
assert_return(in6_addr, -EINVAL);
if (prefixlen < 3 || prefixlen > 128)
return -EINVAL;
if (prefixlen > 64)
/* unusual but allowed, log it */
log_radv(NULL, "Unusual prefix length %d greater than 64", prefixlen);
p->opt.in6_addr = *in6_addr;
p->opt.prefixlen = prefixlen;
return 0;
}
int sd_radv_prefix_get_prefix(
sd_radv_prefix *p,
struct in6_addr *ret_in6_addr,
unsigned char *ret_prefixlen) {
assert_return(p, -EINVAL);
assert_return(ret_in6_addr, -EINVAL);
assert_return(ret_prefixlen, -EINVAL);
*ret_in6_addr = p->opt.in6_addr;
*ret_prefixlen = p->opt.prefixlen;
return 0;
}
int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
assert_return(p, -EINVAL);
SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
return 0;
}
int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p, int address_autoconfiguration) {
assert_return(p, -EINVAL);
SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
return 0;
}
int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p, uint64_t lifetime_usec, uint64_t valid_until) {
assert_return(p, -EINVAL);
p->lifetime_valid_usec = lifetime_usec;
p->valid_until = valid_until;
return 0;
}
int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p, uint64_t lifetime_usec, uint64_t valid_until) {
assert_return(p, -EINVAL);
p->lifetime_preferred_usec = lifetime_usec;
p->preferred_until = valid_until;
return 0;
}
int sd_radv_route_prefix_new(sd_radv_route_prefix **ret) {
sd_radv_route_prefix *p;
assert_return(ret, -EINVAL);
p = new(sd_radv_route_prefix, 1);
if (!p)
return -ENOMEM;
*p = (sd_radv_route_prefix) {
.n_ref = 1,
.opt.type = RADV_OPT_ROUTE_INFORMATION,
.opt.length = DIV_ROUND_UP(sizeof(p->opt), 8),
.opt.prefixlen = 64,
.lifetime_usec = RADV_DEFAULT_VALID_LIFETIME_USEC,
.valid_until = USEC_INFINITY,
};
*ret = p;
return 0;
}
DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_route_prefix, sd_radv_route_prefix, mfree);
int sd_radv_route_prefix_set_prefix(
sd_radv_route_prefix *p,
const struct in6_addr *in6_addr,
unsigned char prefixlen) {
assert_return(p, -EINVAL);
assert_return(in6_addr, -EINVAL);
if (prefixlen > 128)
return -EINVAL;
if (prefixlen > 64)
/* unusual but allowed, log it */
log_radv(NULL, "Unusual prefix length %u greater than 64", prefixlen);
p->opt.in6_addr = *in6_addr;
p->opt.prefixlen = prefixlen;
return 0;
}
int sd_radv_route_prefix_set_lifetime(sd_radv_route_prefix *p, uint64_t lifetime_usec, uint64_t valid_until) {
assert_return(p, -EINVAL);
p->lifetime_usec = lifetime_usec;
p->valid_until = valid_until;
return 0;
}
int sd_radv_pref64_prefix_new(sd_radv_pref64_prefix **ret) {
sd_radv_pref64_prefix *p;
assert_return(ret, -EINVAL);
p = new(sd_radv_pref64_prefix, 1);
if (!p)
return -ENOMEM;
*p = (sd_radv_pref64_prefix) {
.n_ref = 1,
.opt.type = RADV_OPT_PREF64,
.opt.length = 2,
};
*ret = p;
return 0;
}
DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_pref64_prefix, sd_radv_pref64_prefix, mfree);
int sd_radv_pref64_prefix_set_prefix(
sd_radv_pref64_prefix *p,
const struct in6_addr *prefix,
uint8_t prefixlen,
uint64_t lifetime_usec) {
uint16_t pref64_lifetime;
uint8_t prefixlen_code;
int r;
assert_return(p, -EINVAL);
assert_return(prefix, -EINVAL);
r = pref64_prefix_length_to_plc(prefixlen, &prefixlen_code);
if (r < 0)
return log_radv_errno(NULL, r,
"Unsupported PREF64 prefix length %u. Valid lengths are 32, 40, 48, 56, 64 and 96", prefixlen);
if (lifetime_usec > PREF64_MAX_LIFETIME_USEC)
return -EINVAL;
/* RFC 8781 - 4.1 rounding up lifetime to multiply of 8 */
pref64_lifetime = DIV_ROUND_UP(lifetime_usec, 8 * USEC_PER_SEC) << 3;
pref64_lifetime |= prefixlen_code;
unaligned_write_be16(&p->opt.lifetime_and_plc, pref64_lifetime);
memcpy(&p->opt.prefix, prefix, sizeof(p->opt.prefix));
p->in6_addr = *prefix;
p->prefixlen = prefixlen;
return 0;
}
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