diff options
Diffstat (limited to 'src/network/networkd-ndisc.c')
| -rw-r--r-- | src/network/networkd-ndisc.c | 671 |
1 files changed, 671 insertions, 0 deletions
diff --git a/src/network/networkd-ndisc.c b/src/network/networkd-ndisc.c new file mode 100644 index 0000000..e5b8d11 --- /dev/null +++ b/src/network/networkd-ndisc.c @@ -0,0 +1,671 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ +/*** + Copyright © 2014 Intel Corporation. All rights reserved. +***/ + +#include <netinet/icmp6.h> +#include <arpa/inet.h> + +#include "sd-ndisc.h" + +#include "missing_network.h" +#include "networkd-ndisc.h" +#include "networkd-route.h" +#include "strv.h" + +#define NDISC_DNSSL_MAX 64U +#define NDISC_RDNSS_MAX 64U +#define NDISC_PREFIX_LFT_MIN 7200U + +static int ndisc_netlink_message_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) { + 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 int ndisc_router_process_default(Link *link, sd_ndisc_router *rt) { + _cleanup_(route_freep) 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) + return log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m"); + + if (lifetime == 0) /* not a default router */ + return 0; + + r = sd_ndisc_router_get_address(rt, &gateway); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m"); + + 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 0; + } + + 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 0; + } + + r = sd_ndisc_router_get_preference(rt, &preference); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to get default router preference from RA: %m"); + + r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to get RA timestamp: %m"); + + r = sd_ndisc_router_get_mtu(rt, &mtu); + if (r == -ENODATA) + mtu = 0; + else if (r < 0) + return log_link_warning_errno(link, r, "Failed to get default router MTU from RA: %m"); + + r = route_new(&route); + if (r < 0) + return log_link_error_errno(link, r, "Could not allocate route: %m"); + + 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_message_handler); + if (r < 0) { + log_link_warning_errno(link, r, "Could not set default route: %m"); + link_enter_failed(link); + return r; + } + + link->ndisc_messages++; + + return 0; +} + +static int ndisc_router_process_autonomous_prefix(Link *link, sd_ndisc_router *rt) { + _cleanup_(address_freep) 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) + return log_link_warning_errno(link, r, "Failed to get RA timestamp: %m"); + + r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen); + if (r < 0) + return log_link_error_errno(link, r, "Failed to get prefix length: %m"); + + r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_valid); + if (r < 0) + return log_link_error_errno(link, r, "Failed to get prefix valid lifetime: %m"); + + r = sd_ndisc_router_prefix_get_preferred_lifetime(rt, &lifetime_preferred); + if (r < 0) + return log_link_error_errno(link, r, "Failed to get prefix preferred lifetime: %m"); + + /* The preferred lifetime is never greater than the valid lifetime */ + if (lifetime_preferred > lifetime_valid) + return 0; + + r = address_new(&address); + if (r < 0) + return log_link_error_errno(link, r, "Could not allocate address: %m"); + + address->family = AF_INET6; + r = sd_ndisc_router_prefix_get_address(rt, &address->in_addr.in6); + if (r < 0) + return log_link_error_errno(link, r, "Failed to get prefix address: %m"); + + 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 0; /* see RFC4862 section 5.5.3.d */ + + if (address->cinfo.ifa_valid == 0) + return 0; + + r = address_configure(address, link, ndisc_netlink_message_handler, true); + if (r < 0) { + log_link_warning_errno(link, r, "Could not set SLAAC address: %m"); + link_enter_failed(link); + return r; + } + + link->ndisc_messages++; + + return 0; +} + +static int ndisc_router_process_onlink_prefix(Link *link, sd_ndisc_router *rt) { + _cleanup_(route_freep) 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) + return log_link_warning_errno(link, r, "Failed to get RA timestamp: %m"); + + r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen); + if (r < 0) + return log_link_error_errno(link, r, "Failed to get prefix length: %m"); + + r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime); + if (r < 0) + return log_link_error_errno(link, r, "Failed to get prefix lifetime: %m"); + + r = route_new(&route); + if (r < 0) + return log_link_error_errno(link, r, "Could not allocate route: %m"); + + 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) + return log_link_error_errno(link, r, "Failed to get prefix address: %m"); + + r = route_configure(route, link, ndisc_netlink_message_handler); + if (r < 0) { + log_link_warning_errno(link, r, "Could not set prefix route: %m"); + link_enter_failed(link); + return r; + } + + link->ndisc_messages++; + + return 0; +} + +static int ndisc_router_process_route(Link *link, sd_ndisc_router *rt) { + _cleanup_(route_freep) 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) + return log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m"); + + if (lifetime == 0) + return 0; + + r = sd_ndisc_router_get_address(rt, &gateway); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m"); + + r = sd_ndisc_router_route_get_prefixlen(rt, &prefixlen); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to get route prefix length: %m"); + + r = sd_ndisc_router_route_get_preference(rt, &preference); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to get default router preference from RA: %m"); + + r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to get RA timestamp: %m"); + + r = route_new(&route); + if (r < 0) + return log_link_error_errno(link, r, "Could not allocate route: %m"); + + 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) + return log_link_error_errno(link, r, "Failed to get route address: %m"); + + r = route_configure(route, link, ndisc_netlink_message_handler); + if (r < 0) { + log_link_warning_errno(link, r, "Could not set additional route: %m"); + link_enter_failed(link); + return r; + } + + link->ndisc_messages++; + + return 0; +} + +static void ndisc_rdnss_hash_func(const NDiscRDNSS *x, struct siphash *state) { + siphash24_compress(&x->address, sizeof(x->address), state); +} + +static int ndisc_rdnss_compare_func(const NDiscRDNSS *a, const NDiscRDNSS *b) { + return memcmp(&a->address, &b->address, sizeof(a->address)); +} + +DEFINE_PRIVATE_HASH_OPS(ndisc_rdnss_hash_ops, NDiscRDNSS, ndisc_rdnss_hash_func, ndisc_rdnss_compare_func); + +static int 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) + return log_link_warning_errno(link, r, "Failed to get RA timestamp: %m"); + + r = sd_ndisc_router_rdnss_get_lifetime(rt, &lifetime); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to get RDNSS lifetime: %m"); + + n = sd_ndisc_router_rdnss_get_addresses(rt, &a); + if (n < 0) + return log_link_warning_errno(link, n, "Failed to get RDNSS addresses: %m"); + + for (i = 0; i < n; i++) { + _cleanup_free_ NDiscRDNSS *x = NULL; + NDiscRDNSS d = { + .address = a[i], + }, *y; + + if (lifetime == 0) { + (void) set_remove(link->ndisc_rdnss, &d); + link_dirty(link); + continue; + } + + y = set_get(link->ndisc_rdnss, &d); + if (y) { + y->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) + return log_oom(); + + x = new(NDiscRDNSS, 1); + if (!x) + return log_oom(); + + *x = (NDiscRDNSS) { + .address = a[i], + .valid_until = time_now + lifetime * USEC_PER_SEC, + }; + + r = set_put(link->ndisc_rdnss, x); + if (r < 0) + return log_oom(); + + TAKE_PTR(x); + + assert(r > 0); + link_dirty(link); + } + + return 0; +} + +static void ndisc_dnssl_hash_func(const NDiscDNSSL *x, struct siphash *state) { + siphash24_compress(NDISC_DNSSL_DOMAIN(x), strlen(NDISC_DNSSL_DOMAIN(x)), state); +} + +static int ndisc_dnssl_compare_func(const NDiscDNSSL *a, const NDiscDNSSL *b) { + return strcmp(NDISC_DNSSL_DOMAIN(a), NDISC_DNSSL_DOMAIN(b)); +} + +DEFINE_PRIVATE_HASH_OPS(ndisc_dnssl_hash_ops, NDiscDNSSL, ndisc_dnssl_hash_func, 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) + (void) ndisc_router_process_onlink_prefix(link, rt); + if (flags & ND_OPT_PI_FLAG_AUTO) + (void) ndisc_router_process_autonomous_prefix(link, rt); + + break; + } + + case SD_NDISC_OPTION_ROUTE_INFORMATION: + (void) ndisc_router_process_route(link, rt); + break; + + case SD_NDISC_OPTION_RDNSS: + if (link->network->ipv6_accept_ra_use_dns) + (void) ndisc_router_process_rdnss(link, rt); + break; + + case SD_NDISC_OPTION_DNSSL: + if (link->network->ipv6_accept_ra_use_dns) + (void) ndisc_router_process_dnssl(link, rt); + break; + } + + r = sd_ndisc_router_option_next(rt); + } +} + +static int ndisc_router_handler(Link *link, sd_ndisc_router *rt) { + uint64_t flags; + int r = 0; + + assert(link); + assert(link->network); + assert(link->manager); + assert(rt); + + r = sd_ndisc_router_get_flags(rt, &flags); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to get RA flags: %m"); + + 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"); + r = 0; + } + } + + ndisc_router_process_default(link, rt); + ndisc_router_process_options(link, rt); + + return r; +} + +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: + (void) 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); +} |