diff options
Diffstat (limited to 'src/libsystemd-network/sd-ndisc-router.c')
| -rw-r--r-- | src/libsystemd-network/sd-ndisc-router.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/src/libsystemd-network/sd-ndisc-router.c b/src/libsystemd-network/sd-ndisc-router.c new file mode 100644 index 0000000..9ca737d --- /dev/null +++ b/src/libsystemd-network/sd-ndisc-router.c @@ -0,0 +1,344 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/*** + Copyright © 2014 Intel Corporation. All rights reserved. +***/ + +#include <netinet/icmp6.h> + +#include "sd-ndisc.h" + +#include "alloc-util.h" +#include "ndisc-internal.h" +#include "ndisc-router-internal.h" +#include "string-table.h" + +static sd_ndisc_router* ndisc_router_free(sd_ndisc_router *rt) { + if (!rt) + return NULL; + + icmp6_packet_unref(rt->packet); + set_free(rt->options); + return mfree(rt); +} + +DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_ndisc_router, sd_ndisc_router, ndisc_router_free); + +sd_ndisc_router* ndisc_router_new(ICMP6Packet *packet) { + sd_ndisc_router *rt; + + assert(packet); + + rt = new(sd_ndisc_router, 1); + if (!rt) + return NULL; + + *rt = (sd_ndisc_router) { + .n_ref = 1, + .packet = icmp6_packet_ref(packet), + .iterator = ITERATOR_FIRST, + }; + + return rt; +} + +int sd_ndisc_router_set_sender_address(sd_ndisc_router *rt, const struct in6_addr *addr) { + assert_return(rt, -EINVAL); + + return icmp6_packet_set_sender_address(rt->packet, addr); +} + +int sd_ndisc_router_get_sender_address(sd_ndisc_router *rt, struct in6_addr *ret) { + assert_return(rt, -EINVAL); + + return icmp6_packet_get_sender_address(rt->packet, ret); +} + +int sd_ndisc_router_get_timestamp(sd_ndisc_router *rt, clockid_t clock, uint64_t *ret) { + assert_return(rt, -EINVAL); + assert_return(ret, -EINVAL); + + return icmp6_packet_get_timestamp(rt->packet, clock, ret); +} + +#define DEFINE_GET_TIMESTAMP(name) \ + int sd_ndisc_router_##name##_timestamp( \ + sd_ndisc_router *rt, \ + clockid_t clock, \ + uint64_t *ret) { \ + \ + usec_t s, t; \ + int r; \ + \ + assert_return(rt, -EINVAL); \ + assert_return(ret, -EINVAL); \ + \ + r = sd_ndisc_router_##name(rt, &s); \ + if (r < 0) \ + return r; \ + \ + r = sd_ndisc_router_get_timestamp(rt, clock, &t); \ + if (r < 0) \ + return r; \ + \ + *ret = time_span_to_stamp(s, t); \ + return 0; \ + } + +DEFINE_GET_TIMESTAMP(get_lifetime); +DEFINE_GET_TIMESTAMP(prefix_get_valid_lifetime); +DEFINE_GET_TIMESTAMP(prefix_get_preferred_lifetime); +DEFINE_GET_TIMESTAMP(route_get_lifetime); +DEFINE_GET_TIMESTAMP(rdnss_get_lifetime); +DEFINE_GET_TIMESTAMP(dnssl_get_lifetime); +DEFINE_GET_TIMESTAMP(prefix64_get_lifetime); + +int ndisc_router_parse(sd_ndisc *nd, sd_ndisc_router *rt) { + const struct nd_router_advert *a; + int r; + + assert(rt); + assert(rt->packet); + + if (rt->packet->raw_size < sizeof(struct nd_router_advert)) + return log_ndisc_errno(nd, SYNTHETIC_ERRNO(EBADMSG), + "Too small to be a router advertisement, ignoring."); + + a = (const struct nd_router_advert*) rt->packet->raw_packet; + assert(a->nd_ra_type == ND_ROUTER_ADVERT); + assert(a->nd_ra_code == 0); + + rt->hop_limit = a->nd_ra_curhoplimit; + rt->flags = a->nd_ra_flags_reserved; /* the first 8 bits */ + rt->lifetime_usec = be16_sec_to_usec(a->nd_ra_router_lifetime, /* max_as_infinity = */ false); + rt->reachable_time_usec = be32_msec_to_usec(a->nd_ra_reachable, /* mas_as_infinity = */ false); + rt->retransmission_time_usec = be32_msec_to_usec(a->nd_ra_retransmit, /* max_as_infinity = */ false); + + /* RFC 4191 section 2.2 + * Prf (Default Router Preference) + * 2-bit signed integer. Indicates whether to prefer this router over other default routers. If the + * Router Lifetime is zero, the preference value MUST be set to (00) by the sender and MUST be + * ignored by the receiver. If the Reserved (10) value is received, the receiver MUST treat the value + * as if it were (00). */ + rt->preference = (rt->flags >> 3) & 3; + if (rt->preference == SD_NDISC_PREFERENCE_RESERVED) + rt->preference = SD_NDISC_PREFERENCE_MEDIUM; + + r = ndisc_parse_options(rt->packet, &rt->options); + if (r < 0) + return log_ndisc_errno(nd, r, "Failed to parse NDisc options in router advertisement message, ignoring: %m"); + + return 0; +} + +int sd_ndisc_router_get_hop_limit(sd_ndisc_router *rt, uint8_t *ret) { + assert_return(rt, -EINVAL); + assert_return(ret, -EINVAL); + + *ret = rt->hop_limit; + return 0; +} + +int sd_ndisc_router_get_reachable_time(sd_ndisc_router *rt, uint64_t *ret) { + assert_return(rt, -EINVAL); + assert_return(ret, -EINVAL); + + *ret = rt->reachable_time_usec; + return 0; +} + +int sd_ndisc_router_get_retransmission_time(sd_ndisc_router *rt, uint64_t *ret) { + assert_return(rt, -EINVAL); + assert_return(ret, -EINVAL); + + *ret = rt->retransmission_time_usec; + return 0; +} + +int sd_ndisc_router_get_flags(sd_ndisc_router *rt, uint64_t *ret) { + assert_return(rt, -EINVAL); + assert_return(ret, -EINVAL); + + sd_ndisc_option *p = ndisc_option_get_by_type(rt->options, SD_NDISC_OPTION_FLAGS_EXTENSION); + + *ret = rt->flags | (p ? p->extended_flags : 0); + return 0; +} + +int ndisc_router_flags_to_string(uint64_t flags, char **ret) { + _cleanup_free_ char *s = NULL; + + assert(ret); + + if (FLAGS_SET(flags, ND_RA_FLAG_MANAGED) && + !strextend_with_separator(&s, ", ", "managed")) + return -ENOMEM; + + if (FLAGS_SET(flags, ND_RA_FLAG_OTHER) && + !strextend_with_separator(&s, ", ", "other")) + return -ENOMEM; + + if (FLAGS_SET(flags, ND_RA_FLAG_HOME_AGENT) && + !strextend_with_separator(&s, ", ", "home-agent")) + return -ENOMEM; + + *ret = TAKE_PTR(s); + return 0; +} + +int sd_ndisc_router_get_lifetime(sd_ndisc_router *rt, uint64_t *ret) { + assert_return(rt, -EINVAL); + + if (ret) + *ret = rt->lifetime_usec; + + return rt->lifetime_usec > 0; /* Indicate if the router is still valid or not. */ +} + +int sd_ndisc_router_get_preference(sd_ndisc_router *rt, uint8_t *ret) { + assert_return(rt, -EINVAL); + assert_return(ret, -EINVAL); + + *ret = rt->preference; + return 0; +} + +static const char* const ndisc_router_preference_table[] = { + [SD_NDISC_PREFERENCE_LOW] = "low", + [SD_NDISC_PREFERENCE_MEDIUM] = "medium", + [SD_NDISC_PREFERENCE_HIGH] = "high", + [SD_NDISC_PREFERENCE_RESERVED] = "reserved", +}; + +DEFINE_STRING_TABLE_LOOKUP_TO_STRING(ndisc_router_preference, int); + +int sd_ndisc_router_get_sender_mac(sd_ndisc_router *rt, struct ether_addr *ret) { + assert_return(rt, -EINVAL); + + return ndisc_option_get_mac(rt->options, SD_NDISC_OPTION_SOURCE_LL_ADDRESS, ret); +} + +int sd_ndisc_router_get_mtu(sd_ndisc_router *rt, uint32_t *ret) { + assert_return(rt, -EINVAL); + assert_return(ret, -EINVAL); + + sd_ndisc_option *p = ndisc_option_get_by_type(rt->options, SD_NDISC_OPTION_MTU); + if (!p) + return -ENODATA; + + *ret = p->mtu; + return 0; +} + +int sd_ndisc_router_get_captive_portal(sd_ndisc_router *rt, const char **ret) { + assert_return(rt, -EINVAL); + assert_return(ret, -EINVAL); + + sd_ndisc_option *p = ndisc_option_get_by_type(rt->options, SD_NDISC_OPTION_CAPTIVE_PORTAL); + if (!p) + return -ENODATA; + + *ret = p->captive_portal; + return 0; +} + +int sd_ndisc_router_option_rewind(sd_ndisc_router *rt) { + assert_return(rt, -EINVAL); + + rt->iterator = ITERATOR_FIRST; + return sd_ndisc_router_option_next(rt); +} + +int sd_ndisc_router_option_next(sd_ndisc_router *rt) { + assert_return(rt, -EINVAL); + + return set_iterate(rt->options, &rt->iterator, (void**) &rt->current_option); +} + +int sd_ndisc_router_option_get_type(sd_ndisc_router *rt, uint8_t *ret) { + assert_return(rt, -EINVAL); + assert_return(ret, -EINVAL); + + if (!rt->current_option) + return -ENODATA; + + *ret = rt->current_option->type; + return 0; +} + +int sd_ndisc_router_option_is_type(sd_ndisc_router *rt, uint8_t type) { + uint8_t t; + int r; + + assert_return(rt, -EINVAL); + + r = sd_ndisc_router_option_get_type(rt, &t); + if (r < 0) + return r; + + return t == type; +} + +int sd_ndisc_router_option_get_raw(sd_ndisc_router *rt, const uint8_t **ret, size_t *ret_size) { + assert_return(rt, -EINVAL); + + if (!rt->current_option) + return -ENODATA; + + return ndisc_option_parse(rt->packet, rt->current_option->offset, NULL, ret_size, ret); +} + +#define DEFINE_GETTER(name, type, element, element_type) \ + int sd_ndisc_router_##name##_get_##element( \ + sd_ndisc_router *rt, \ + element_type *ret) { \ + \ + int r; \ + \ + assert_return(rt, -EINVAL); \ + assert_return(ret, -EINVAL); \ + \ + r = sd_ndisc_router_option_is_type(rt, type); \ + if (r < 0) \ + return r; \ + if (r == 0) \ + return -EMEDIUMTYPE; \ + \ + *ret = rt->current_option->name.element; \ + return 0; \ + } + +DEFINE_GETTER(prefix, SD_NDISC_OPTION_PREFIX_INFORMATION, flags, uint8_t); +DEFINE_GETTER(prefix, SD_NDISC_OPTION_PREFIX_INFORMATION, prefixlen, uint8_t); +DEFINE_GETTER(prefix, SD_NDISC_OPTION_PREFIX_INFORMATION, address, struct in6_addr); +DEFINE_GETTER(prefix, SD_NDISC_OPTION_PREFIX_INFORMATION, valid_lifetime, uint64_t); +DEFINE_GETTER(prefix, SD_NDISC_OPTION_PREFIX_INFORMATION, preferred_lifetime, uint64_t); + +DEFINE_GETTER(route, SD_NDISC_OPTION_ROUTE_INFORMATION, preference, uint8_t); +DEFINE_GETTER(route, SD_NDISC_OPTION_ROUTE_INFORMATION, prefixlen, uint8_t); +DEFINE_GETTER(route, SD_NDISC_OPTION_ROUTE_INFORMATION, address, struct in6_addr); +DEFINE_GETTER(route, SD_NDISC_OPTION_ROUTE_INFORMATION, lifetime, uint64_t); + +DEFINE_GETTER(rdnss, SD_NDISC_OPTION_RDNSS, lifetime, uint64_t); + +int sd_ndisc_router_rdnss_get_addresses(sd_ndisc_router *rt, const struct in6_addr **ret) { + int r; + + assert_return(rt, -EINVAL); + assert_return(ret, -EINVAL); + + r = sd_ndisc_router_option_is_type(rt, SD_NDISC_OPTION_RDNSS); + if (r < 0) + return r; + if (r == 0) + return -EMEDIUMTYPE; + + *ret = rt->current_option->rdnss.addresses; + return (int) rt->current_option->rdnss.n_addresses; +} + +DEFINE_GETTER(dnssl, SD_NDISC_OPTION_DNSSL, domains, char**); +DEFINE_GETTER(dnssl, SD_NDISC_OPTION_DNSSL, lifetime, uint64_t); + +DEFINE_GETTER(prefix64, SD_NDISC_OPTION_PREF64, prefixlen, uint8_t); +DEFINE_GETTER(prefix64, SD_NDISC_OPTION_PREF64, prefix, struct in6_addr); +DEFINE_GETTER(prefix64, SD_NDISC_OPTION_PREF64, lifetime, uint64_t); 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