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Systemd/src/network/networkd-ndisc.c
Zbigniew Jędrzejewski-Szmek 11a1589223 tree-wide: drop license boilerplate 
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.

I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
2018-04-06 18:58:55 +02:00

733 lines
24 KiB
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/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
Copyright (C) 2014 Intel Corporation. All rights reserved.
***/
#include <netinet/icmp6.h>
#include <arpa/inet.h>
#include "sd-ndisc.h"
#include "networkd-ndisc.h"
#include "networkd-route.h"
#define NDISC_DNSSL_MAX 64U
#define NDISC_RDNSS_MAX 64U
#define NDISC_PREFIX_LFT_MIN 7200U
static int ndisc_netlink_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) {
_cleanup_link_unref_ Link *link = userdata;
int r;
assert(link);
assert(link->ndisc_messages > 0);
link->ndisc_messages--;
r = sd_netlink_message_get_errno(m);
if (r < 0 && r != -EEXIST)
log_link_error_errno(link, r, "Could not set NDisc route or address: %m");
if (link->ndisc_messages == 0) {
link->ndisc_configured = true;
link_check_ready(link);
}
return 1;
}
static void ndisc_router_process_default(Link *link, sd_ndisc_router *rt) {
_cleanup_route_free_ Route *route = NULL;
struct in6_addr gateway;
uint16_t lifetime;
unsigned preference;
uint32_t mtu;
usec_t time_now;
int r;
Address *address;
Iterator i;
assert(link);
assert(rt);
r = sd_ndisc_router_get_lifetime(rt, &lifetime);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
return;
}
if (lifetime == 0) /* not a default router */
return;
r = sd_ndisc_router_get_address(rt, &gateway);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
return;
}
SET_FOREACH(address, link->addresses, i) {
if (!memcmp(&gateway, &address->in_addr.in6,
sizeof(address->in_addr.in6))) {
char buffer[INET6_ADDRSTRLEN];
log_link_debug(link, "No NDisc route added, gateway %s matches local address",
inet_ntop(AF_INET6,
&address->in_addr.in6,
buffer, sizeof(buffer)));
return;
}
}
SET_FOREACH(address, link->addresses_foreign, i) {
if (!memcmp(&gateway, &address->in_addr.in6,
sizeof(address->in_addr.in6))) {
char buffer[INET6_ADDRSTRLEN];
log_link_debug(link, "No NDisc route added, gateway %s matches local address",
inet_ntop(AF_INET6,
&address->in_addr.in6,
buffer, sizeof(buffer)));
return;
}
}
r = sd_ndisc_router_get_preference(rt, &preference);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get default router preference from RA: %m");
return;
}
r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
return;
}
r = sd_ndisc_router_get_mtu(rt, &mtu);
if (r == -ENODATA)
mtu = 0;
else if (r < 0) {
log_link_warning_errno(link, r, "Failed to get default router MTU from RA: %m");
return;
}
r = route_new(&route);
if (r < 0) {
log_link_error_errno(link, r, "Could not allocate route: %m");
return;
}
route->family = AF_INET6;
route->table = link->network->ipv6_accept_ra_route_table;
route->priority = link->network->dhcp_route_metric;
route->protocol = RTPROT_RA;
route->pref = preference;
route->gw.in6 = gateway;
route->lifetime = time_now + lifetime * USEC_PER_SEC;
route->mtu = mtu;
r = route_configure(route, link, ndisc_netlink_handler);
if (r < 0) {
log_link_warning_errno(link, r, "Could not set default route: %m");
link_enter_failed(link);
return;
}
link->ndisc_messages++;
}
static void ndisc_router_process_autonomous_prefix(Link *link, sd_ndisc_router *rt) {
_cleanup_address_free_ Address *address = NULL;
Address *existing_address;
uint32_t lifetime_valid, lifetime_preferred, lifetime_remaining;
usec_t time_now;
unsigned prefixlen;
int r;
assert(link);
assert(rt);
r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
return;
}
r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
if (r < 0) {
log_link_error_errno(link, r, "Failed to get prefix length: %m");
return;
}
r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_valid);
if (r < 0) {
log_link_error_errno(link, r, "Failed to get prefix valid lifetime: %m");
return;
}
r = sd_ndisc_router_prefix_get_preferred_lifetime(rt, &lifetime_preferred);
if (r < 0) {
log_link_error_errno(link, r, "Failed to get prefix preferred lifetime: %m");
return;
}
/* The preferred lifetime is never greater than the valid lifetime */
if (lifetime_preferred > lifetime_valid)
return;
r = address_new(&address);
if (r < 0) {
log_link_error_errno(link, r, "Could not allocate address: %m");
return;
}
address->family = AF_INET6;
r = sd_ndisc_router_prefix_get_address(rt, &address->in_addr.in6);
if (r < 0) {
log_link_error_errno(link, r, "Failed to get prefix address: %m");
return;
}
if (in_addr_is_null(AF_INET6, (const union in_addr_union *) &link->network->ipv6_token) == 0)
memcpy(((char *)&address->in_addr.in6) + 8, ((char *)&link->network->ipv6_token) + 8, 8);
else {
/* see RFC4291 section 2.5.1 */
address->in_addr.in6.s6_addr[8] = link->mac.ether_addr_octet[0];
address->in_addr.in6.s6_addr[8] ^= 1 << 1;
address->in_addr.in6.s6_addr[9] = link->mac.ether_addr_octet[1];
address->in_addr.in6.s6_addr[10] = link->mac.ether_addr_octet[2];
address->in_addr.in6.s6_addr[11] = 0xff;
address->in_addr.in6.s6_addr[12] = 0xfe;
address->in_addr.in6.s6_addr[13] = link->mac.ether_addr_octet[3];
address->in_addr.in6.s6_addr[14] = link->mac.ether_addr_octet[4];
address->in_addr.in6.s6_addr[15] = link->mac.ether_addr_octet[5];
}
address->prefixlen = prefixlen;
address->flags = IFA_F_NOPREFIXROUTE|IFA_F_MANAGETEMPADDR;
address->cinfo.ifa_prefered = lifetime_preferred;
/* see RFC4862 section 5.5.3.e */
r = address_get(link, address->family, &address->in_addr, address->prefixlen, &existing_address);
if (r > 0) {
lifetime_remaining = existing_address->cinfo.tstamp / 100 + existing_address->cinfo.ifa_valid - time_now / USEC_PER_SEC;
if (lifetime_valid > NDISC_PREFIX_LFT_MIN || lifetime_valid > lifetime_remaining)
address->cinfo.ifa_valid = lifetime_valid;
else if (lifetime_remaining <= NDISC_PREFIX_LFT_MIN)
address->cinfo.ifa_valid = lifetime_remaining;
else
address->cinfo.ifa_valid = NDISC_PREFIX_LFT_MIN;
} else if (lifetime_valid > 0)
address->cinfo.ifa_valid = lifetime_valid;
else
return; /* see RFC4862 section 5.5.3.d */
if (address->cinfo.ifa_valid == 0)
return;
r = address_configure(address, link, ndisc_netlink_handler, true);
if (r < 0) {
log_link_warning_errno(link, r, "Could not set SLAAC address: %m");
link_enter_failed(link);
return;
}
link->ndisc_messages++;
}
static void ndisc_router_process_onlink_prefix(Link *link, sd_ndisc_router *rt) {
_cleanup_route_free_ Route *route = NULL;
usec_t time_now;
uint32_t lifetime;
unsigned prefixlen;
int r;
assert(link);
assert(rt);
r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
return;
}
r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
if (r < 0) {
log_link_error_errno(link, r, "Failed to get prefix length: %m");
return;
}
r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime);
if (r < 0) {
log_link_error_errno(link, r, "Failed to get prefix lifetime: %m");
return;
}
r = route_new(&route);
if (r < 0) {
log_link_error_errno(link, r, "Could not allocate route: %m");
return;
}
route->family = AF_INET6;
route->table = link->network->ipv6_accept_ra_route_table;
route->priority = link->network->dhcp_route_metric;
route->protocol = RTPROT_RA;
route->flags = RTM_F_PREFIX;
route->dst_prefixlen = prefixlen;
route->lifetime = time_now + lifetime * USEC_PER_SEC;
r = sd_ndisc_router_prefix_get_address(rt, &route->dst.in6);
if (r < 0) {
log_link_error_errno(link, r, "Failed to get prefix address: %m");
return;
}
r = route_configure(route, link, ndisc_netlink_handler);
if (r < 0) {
log_link_warning_errno(link, r, "Could not set prefix route: %m");
link_enter_failed(link);
return;
}
link->ndisc_messages++;
}
static void ndisc_router_process_route(Link *link, sd_ndisc_router *rt) {
_cleanup_route_free_ Route *route = NULL;
struct in6_addr gateway;
uint32_t lifetime;
unsigned preference, prefixlen;
usec_t time_now;
int r;
assert(link);
r = sd_ndisc_router_route_get_lifetime(rt, &lifetime);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
return;
}
if (lifetime == 0)
return;
r = sd_ndisc_router_get_address(rt, &gateway);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
return;
}
r = sd_ndisc_router_route_get_prefixlen(rt, &prefixlen);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get route prefix length: %m");
return;
}
r = sd_ndisc_router_route_get_preference(rt, &preference);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get default router preference from RA: %m");
return;
}
r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
return;
}
r = route_new(&route);
if (r < 0) {
log_link_error_errno(link, r, "Could not allocate route: %m");
return;
}
route->family = AF_INET6;
route->table = link->network->ipv6_accept_ra_route_table;
route->protocol = RTPROT_RA;
route->pref = preference;
route->gw.in6 = gateway;
route->dst_prefixlen = prefixlen;
route->lifetime = time_now + lifetime * USEC_PER_SEC;
r = sd_ndisc_router_route_get_address(rt, &route->dst.in6);
if (r < 0) {
log_link_error_errno(link, r, "Failed to get route address: %m");
return;
}
r = route_configure(route, link, ndisc_netlink_handler);
if (r < 0) {
log_link_warning_errno(link, r, "Could not set additional route: %m");
link_enter_failed(link);
return;
}
link->ndisc_messages++;
}
static void ndisc_rdnss_hash_func(const void *p, struct siphash *state) {
const NDiscRDNSS *x = p;
siphash24_compress(&x->address, sizeof(x->address), state);
}
static int ndisc_rdnss_compare_func(const void *_a, const void *_b) {
const NDiscRDNSS *a = _a, *b = _b;
return memcmp(&a->address, &b->address, sizeof(a->address));
}
static const struct hash_ops ndisc_rdnss_hash_ops = {
.hash = ndisc_rdnss_hash_func,
.compare = ndisc_rdnss_compare_func
};
static void ndisc_router_process_rdnss(Link *link, sd_ndisc_router *rt) {
uint32_t lifetime;
const struct in6_addr *a;
usec_t time_now;
int i, n, r;
assert(link);
assert(rt);
r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
return;
}
r = sd_ndisc_router_rdnss_get_lifetime(rt, &lifetime);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get RDNSS lifetime: %m");
return;
}
n = sd_ndisc_router_rdnss_get_addresses(rt, &a);
if (n < 0) {
log_link_warning_errno(link, n, "Failed to get RDNSS addresses: %m");
return;
}
for (i = 0; i < n; i++) {
NDiscRDNSS d = {
.address = a[i]
}, *x;
if (lifetime == 0) {
(void) set_remove(link->ndisc_rdnss, &d);
link_dirty(link);
continue;
}
x = set_get(link->ndisc_rdnss, &d);
if (x) {
x->valid_until = time_now + lifetime * USEC_PER_SEC;
continue;
}
ndisc_vacuum(link);
if (set_size(link->ndisc_rdnss) >= NDISC_RDNSS_MAX) {
log_link_warning(link, "Too many RDNSS records per link, ignoring.");
continue;
}
r = set_ensure_allocated(&link->ndisc_rdnss, &ndisc_rdnss_hash_ops);
if (r < 0) {
log_oom();
return;
}
x = new0(NDiscRDNSS, 1);
if (!x) {
log_oom();
return;
}
x->address = a[i];
x->valid_until = time_now + lifetime * USEC_PER_SEC;
r = set_put(link->ndisc_rdnss, x);
if (r < 0) {
free(x);
log_oom();
return;
}
assert(r > 0);
link_dirty(link);
}
}
static void ndisc_dnssl_hash_func(const void *p, struct siphash *state) {
const NDiscDNSSL *x = p;
siphash24_compress(NDISC_DNSSL_DOMAIN(x), strlen(NDISC_DNSSL_DOMAIN(x)), state);
}
static int ndisc_dnssl_compare_func(const void *_a, const void *_b) {
const NDiscDNSSL *a = _a, *b = _b;
return strcmp(NDISC_DNSSL_DOMAIN(a), NDISC_DNSSL_DOMAIN(b));
}
static const struct hash_ops ndisc_dnssl_hash_ops = {
.hash = ndisc_dnssl_hash_func,
.compare = ndisc_dnssl_compare_func
};
static void ndisc_router_process_dnssl(Link *link, sd_ndisc_router *rt) {
_cleanup_strv_free_ char **l = NULL;
uint32_t lifetime;
usec_t time_now;
char **i;
int r;
assert(link);
assert(rt);
r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get RA timestamp: %m");
return;
}
r = sd_ndisc_router_dnssl_get_lifetime(rt, &lifetime);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get RDNSS lifetime: %m");
return;
}
r = sd_ndisc_router_dnssl_get_domains(rt, &l);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get RDNSS addresses: %m");
return;
}
STRV_FOREACH(i, l) {
_cleanup_free_ NDiscDNSSL *s;
NDiscDNSSL *x;
s = malloc0(ALIGN(sizeof(NDiscDNSSL)) + strlen(*i) + 1);
if (!s) {
log_oom();
return;
}
strcpy(NDISC_DNSSL_DOMAIN(s), *i);
if (lifetime == 0) {
(void) set_remove(link->ndisc_dnssl, s);
link_dirty(link);
continue;
}
x = set_get(link->ndisc_dnssl, s);
if (x) {
x->valid_until = time_now + lifetime * USEC_PER_SEC;
continue;
}
ndisc_vacuum(link);
if (set_size(link->ndisc_dnssl) >= NDISC_DNSSL_MAX) {
log_link_warning(link, "Too many DNSSL records per link, ignoring.");
continue;
}
r = set_ensure_allocated(&link->ndisc_dnssl, &ndisc_dnssl_hash_ops);
if (r < 0) {
log_oom();
return;
}
s->valid_until = time_now + lifetime * USEC_PER_SEC;
r = set_put(link->ndisc_dnssl, s);
if (r < 0) {
log_oom();
return;
}
s = NULL;
assert(r > 0);
link_dirty(link);
}
}
static void ndisc_router_process_options(Link *link, sd_ndisc_router *rt) {
int r;
assert(link);
assert(rt);
r = sd_ndisc_router_option_rewind(rt);
for (;;) {
uint8_t type;
if (r < 0) {
log_link_warning_errno(link, r, "Failed to iterate through options: %m");
return;
}
if (r == 0) /* EOF */
break;
r = sd_ndisc_router_option_get_type(rt, &type);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get RA option type: %m");
return;
}
switch (type) {
case SD_NDISC_OPTION_PREFIX_INFORMATION: {
uint8_t flags;
r = sd_ndisc_router_prefix_get_flags(rt, &flags);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get RA prefix flags: %m");
return;
}
if (flags & ND_OPT_PI_FLAG_ONLINK)
ndisc_router_process_onlink_prefix(link, rt);
if (flags & ND_OPT_PI_FLAG_AUTO)
ndisc_router_process_autonomous_prefix(link, rt);
break;
}
case SD_NDISC_OPTION_ROUTE_INFORMATION:
ndisc_router_process_route(link, rt);
break;
case SD_NDISC_OPTION_RDNSS:
if (link->network->ipv6_accept_ra_use_dns)
ndisc_router_process_rdnss(link, rt);
break;
case SD_NDISC_OPTION_DNSSL:
if (link->network->ipv6_accept_ra_use_dns)
ndisc_router_process_dnssl(link, rt);
break;
}
r = sd_ndisc_router_option_next(rt);
}
}
static void ndisc_router_handler(Link *link, sd_ndisc_router *rt) {
uint64_t flags;
int r;
assert(link);
assert(link->network);
assert(link->manager);
assert(rt);
r = sd_ndisc_router_get_flags(rt, &flags);
if (r < 0) {
log_link_warning_errno(link, r, "Failed to get RA flags: %m");
return;
}
if (flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER)) {
/* (re)start DHCPv6 client in stateful or stateless mode according to RA flags */
r = dhcp6_request_address(link, !(flags & ND_RA_FLAG_MANAGED));
if (r < 0 && r != -EBUSY)
log_link_warning_errno(link, r, "Could not acquire DHCPv6 lease on NDisc request: %m");
else
log_link_debug(link, "Acquiring DHCPv6 lease on NDisc request");
}
ndisc_router_process_default(link, rt);
ndisc_router_process_options(link, rt);
}
static void ndisc_handler(sd_ndisc *nd, sd_ndisc_event event, sd_ndisc_router *rt, void *userdata) {
Link *link = userdata;
assert(link);
if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
return;
switch (event) {
case SD_NDISC_EVENT_ROUTER:
ndisc_router_handler(link, rt);
break;
case SD_NDISC_EVENT_TIMEOUT:
link->ndisc_configured = true;
link_check_ready(link);
break;
default:
log_link_warning(link, "IPv6 Neighbor Discovery unknown event: %d", event);
}
}
int ndisc_configure(Link *link) {
int r;
assert(link);
r = sd_ndisc_new(&link->ndisc);
if (r < 0)
return r;
r = sd_ndisc_attach_event(link->ndisc, NULL, 0);
if (r < 0)
return r;
r = sd_ndisc_set_mac(link->ndisc, &link->mac);
if (r < 0)
return r;
r = sd_ndisc_set_ifindex(link->ndisc, link->ifindex);
if (r < 0)
return r;
r = sd_ndisc_set_callback(link->ndisc, ndisc_handler, link);
if (r < 0)
return r;
return 0;
}
void ndisc_vacuum(Link *link) {
NDiscRDNSS *r;
NDiscDNSSL *d;
Iterator i;
usec_t time_now;
assert(link);
/* Removes all RDNSS and DNSSL entries whose validity time has passed */
time_now = now(clock_boottime_or_monotonic());
SET_FOREACH(r, link->ndisc_rdnss, i)
if (r->valid_until < time_now) {
free(set_remove(link->ndisc_rdnss, r));
link_dirty(link);
}
SET_FOREACH(d, link->ndisc_dnssl, i)
if (d->valid_until < time_now) {
free(set_remove(link->ndisc_dnssl, d));
link_dirty(link);
}
}
void ndisc_flush(Link *link) {
assert(link);
/* Removes all RDNSS and DNSSL entries, without exception */
link->ndisc_rdnss = set_free_free(link->ndisc_rdnss);
link->ndisc_dnssl = set_free_free(link->ndisc_dnssl);
}
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