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-rw-r--r--src/libsystemd-network/ndisc-router.c749
1 files changed, 749 insertions, 0 deletions
diff --git a/src/libsystemd-network/ndisc-router.c b/src/libsystemd-network/ndisc-router.c
new file mode 100644
index 0000000..6935311
--- /dev/null
+++ b/src/libsystemd-network/ndisc-router.c
@@ -0,0 +1,749 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+/***
+ Copyright © 2014 Intel Corporation. All rights reserved.
+***/
+
+#include <netinet/icmp6.h>
+
+#include "sd-ndisc.h"
+
+#include "alloc-util.h"
+#include "dns-domain.h"
+#include "hostname-util.h"
+#include "missing.h"
+#include "ndisc-internal.h"
+#include "ndisc-router.h"
+#include "strv.h"
+
+DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_ndisc_router, sd_ndisc_router, mfree);
+
+sd_ndisc_router *ndisc_router_new(size_t raw_size) {
+ sd_ndisc_router *rt;
+
+ rt = malloc0(ALIGN(sizeof(sd_ndisc_router)) + raw_size);
+ if (!rt)
+ return NULL;
+
+ rt->raw_size = raw_size;
+ rt->n_ref = 1;
+
+ return rt;
+}
+
+_public_ int sd_ndisc_router_from_raw(sd_ndisc_router **ret, const void *raw, size_t raw_size) {
+ _cleanup_(sd_ndisc_router_unrefp) sd_ndisc_router *rt = NULL;
+ int r;
+
+ assert_return(ret, -EINVAL);
+ assert_return(raw || raw_size <= 0, -EINVAL);
+
+ rt = ndisc_router_new(raw_size);
+ if (!rt)
+ return -ENOMEM;
+
+ memcpy(NDISC_ROUTER_RAW(rt), raw, raw_size);
+ r = ndisc_router_parse(rt);
+ if (r < 0)
+ return r;
+
+ *ret = TAKE_PTR(rt);
+
+ return r;
+}
+
+_public_ int sd_ndisc_router_get_address(sd_ndisc_router *rt, struct in6_addr *ret_addr) {
+ assert_return(rt, -EINVAL);
+ assert_return(ret_addr, -EINVAL);
+
+ if (IN6_IS_ADDR_UNSPECIFIED(&rt->address))
+ return -ENODATA;
+
+ *ret_addr = rt->address;
+ return 0;
+}
+
+_public_ int sd_ndisc_router_get_timestamp(sd_ndisc_router *rt, clockid_t clock, uint64_t *ret) {
+ assert_return(rt, -EINVAL);
+ assert_return(TRIPLE_TIMESTAMP_HAS_CLOCK(clock), -EOPNOTSUPP);
+ assert_return(clock_supported(clock), -EOPNOTSUPP);
+ assert_return(ret, -EINVAL);
+
+ if (!triple_timestamp_is_set(&rt->timestamp))
+ return -ENODATA;
+
+ *ret = triple_timestamp_by_clock(&rt->timestamp, clock);
+ return 0;
+}
+
+_public_ int sd_ndisc_router_get_raw(sd_ndisc_router *rt, const void **ret, size_t *size) {
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+ assert_return(size, -EINVAL);
+
+ *ret = NDISC_ROUTER_RAW(rt);
+ *size = rt->raw_size;
+
+ return 0;
+}
+
+int ndisc_router_parse(sd_ndisc_router *rt) {
+ struct nd_router_advert *a;
+ const uint8_t *p;
+ bool has_mtu = false, has_flag_extension = false;
+ size_t left;
+
+ assert(rt);
+
+ if (rt->raw_size < sizeof(struct nd_router_advert)) {
+ log_ndisc("Too small to be a router advertisement, ignoring.");
+ return -EBADMSG;
+ }
+
+ /* Router advertisement packets are neatly aligned to 64bit boundaries, hence we can access them directly */
+ a = NDISC_ROUTER_RAW(rt);
+
+ if (a->nd_ra_type != ND_ROUTER_ADVERT) {
+ log_ndisc("Received ND packet that is not a router advertisement, ignoring.");
+ return -EBADMSG;
+ }
+
+ if (a->nd_ra_code != 0) {
+ log_ndisc("Received ND packet with wrong RA code, ignoring.");
+ return -EBADMSG;
+ }
+
+ rt->hop_limit = a->nd_ra_curhoplimit;
+ rt->flags = a->nd_ra_flags_reserved; /* the first 8bit */
+ rt->lifetime = be16toh(a->nd_ra_router_lifetime);
+
+ rt->preference = (rt->flags >> 3) & 3;
+ if (!IN_SET(rt->preference, SD_NDISC_PREFERENCE_LOW, SD_NDISC_PREFERENCE_HIGH))
+ rt->preference = SD_NDISC_PREFERENCE_MEDIUM;
+
+ p = (const uint8_t*) NDISC_ROUTER_RAW(rt) + sizeof(struct nd_router_advert);
+ left = rt->raw_size - sizeof(struct nd_router_advert);
+
+ for (;;) {
+ uint8_t type;
+ size_t length;
+
+ if (left == 0)
+ break;
+
+ if (left < 2) {
+ log_ndisc("Option lacks header, ignoring datagram.");
+ return -EBADMSG;
+ }
+
+ type = p[0];
+ length = p[1] * 8;
+
+ if (length == 0) {
+ log_ndisc("Zero-length option, ignoring datagram.");
+ return -EBADMSG;
+ }
+ if (left < length) {
+ log_ndisc("Option truncated, ignoring datagram.");
+ return -EBADMSG;
+ }
+
+ switch (type) {
+
+ case SD_NDISC_OPTION_PREFIX_INFORMATION:
+
+ if (length != 4*8) {
+ log_ndisc("Prefix option of invalid size, ignoring datagram.");
+ return -EBADMSG;
+ }
+
+ if (p[2] > 128) {
+ log_ndisc("Bad prefix length, ignoring datagram.");
+ return -EBADMSG;
+ }
+
+ break;
+
+ case SD_NDISC_OPTION_MTU: {
+ uint32_t m;
+
+ if (has_mtu) {
+ log_ndisc("MTU option specified twice, ignoring.");
+ break;
+ }
+
+ if (length != 8) {
+ log_ndisc("MTU option of invalid size, ignoring datagram.");
+ return -EBADMSG;
+ }
+
+ m = be32toh(*(uint32_t*) (p + 4));
+ if (m >= IPV6_MIN_MTU) /* ignore invalidly small MTUs */
+ rt->mtu = m;
+
+ has_mtu = true;
+ break;
+ }
+
+ case SD_NDISC_OPTION_ROUTE_INFORMATION:
+ if (length < 1*8 || length > 3*8) {
+ log_ndisc("Route information option of invalid size, ignoring datagram.");
+ return -EBADMSG;
+ }
+
+ if (p[2] > 128) {
+ log_ndisc("Bad route prefix length, ignoring datagram.");
+ return -EBADMSG;
+ }
+
+ break;
+
+ case SD_NDISC_OPTION_RDNSS:
+ if (length < 3*8 || (length % (2*8)) != 1*8) {
+ log_ndisc("RDNSS option has invalid size.");
+ return -EBADMSG;
+ }
+
+ break;
+
+ case SD_NDISC_OPTION_FLAGS_EXTENSION:
+
+ if (has_flag_extension) {
+ log_ndisc("Flags extension option specified twice, ignoring.");
+ break;
+ }
+
+ if (length < 1*8) {
+ log_ndisc("Flags extension option has invalid size.");
+ return -EBADMSG;
+ }
+
+ /* Add in the additional flags bits */
+ rt->flags |=
+ ((uint64_t) p[2] << 8) |
+ ((uint64_t) p[3] << 16) |
+ ((uint64_t) p[4] << 24) |
+ ((uint64_t) p[5] << 32) |
+ ((uint64_t) p[6] << 40) |
+ ((uint64_t) p[7] << 48);
+
+ has_flag_extension = true;
+ break;
+
+ case SD_NDISC_OPTION_DNSSL:
+ if (length < 2*8) {
+ log_ndisc("DNSSL option has invalid size.");
+ return -EBADMSG;
+ }
+
+ break;
+ }
+
+ p += length, left -= length;
+ }
+
+ rt->rindex = sizeof(struct nd_router_advert);
+ return 0;
+}
+
+_public_ 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;
+}
+
+_public_ int sd_ndisc_router_get_flags(sd_ndisc_router *rt, uint64_t *ret_flags) {
+ assert_return(rt, -EINVAL);
+ assert_return(ret_flags, -EINVAL);
+
+ *ret_flags = rt->flags;
+ return 0;
+}
+
+_public_ int sd_ndisc_router_get_lifetime(sd_ndisc_router *rt, uint16_t *ret_lifetime) {
+ assert_return(rt, -EINVAL);
+ assert_return(ret_lifetime, -EINVAL);
+
+ *ret_lifetime = rt->lifetime;
+ return 0;
+}
+
+_public_ int sd_ndisc_router_get_preference(sd_ndisc_router *rt, unsigned *ret) {
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ *ret = rt->preference;
+ return 0;
+}
+
+_public_ int sd_ndisc_router_get_mtu(sd_ndisc_router *rt, uint32_t *ret) {
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ if (rt->mtu <= 0)
+ return -ENODATA;
+
+ *ret = rt->mtu;
+ return 0;
+}
+
+_public_ int sd_ndisc_router_option_rewind(sd_ndisc_router *rt) {
+ assert_return(rt, -EINVAL);
+
+ assert(rt->raw_size >= sizeof(struct nd_router_advert));
+ rt->rindex = sizeof(struct nd_router_advert);
+
+ return rt->rindex < rt->raw_size;
+}
+
+_public_ int sd_ndisc_router_option_next(sd_ndisc_router *rt) {
+ size_t length;
+
+ assert_return(rt, -EINVAL);
+
+ if (rt->rindex == rt->raw_size) /* EOF */
+ return -ESPIPE;
+
+ if (rt->rindex + 2 > rt->raw_size) /* Truncated message */
+ return -EBADMSG;
+
+ length = NDISC_ROUTER_OPTION_LENGTH(rt);
+ if (rt->rindex + length > rt->raw_size)
+ return -EBADMSG;
+
+ rt->rindex += length;
+ return rt->rindex < rt->raw_size;
+}
+
+_public_ int sd_ndisc_router_option_get_type(sd_ndisc_router *rt, uint8_t *ret) {
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ if (rt->rindex == rt->raw_size) /* EOF */
+ return -ESPIPE;
+
+ if (rt->rindex + 2 > rt->raw_size) /* Truncated message */
+ return -EBADMSG;
+
+ *ret = NDISC_ROUTER_OPTION_TYPE(rt);
+ return 0;
+}
+
+_public_ int sd_ndisc_router_option_is_type(sd_ndisc_router *rt, uint8_t type) {
+ uint8_t k;
+ int r;
+
+ assert_return(rt, -EINVAL);
+
+ r = sd_ndisc_router_option_get_type(rt, &k);
+ if (r < 0)
+ return r;
+
+ return type == k;
+}
+
+_public_ int sd_ndisc_router_option_get_raw(sd_ndisc_router *rt, const void **ret, size_t *size) {
+ size_t length;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+ assert_return(size, -EINVAL);
+
+ /* Note that this returns the full option, including the option header */
+
+ if (rt->rindex + 2 > rt->raw_size)
+ return -EBADMSG;
+
+ length = NDISC_ROUTER_OPTION_LENGTH(rt);
+ if (rt->rindex + length > rt->raw_size)
+ return -EBADMSG;
+
+ *ret = (uint8_t*) NDISC_ROUTER_RAW(rt) + rt->rindex;
+ *size = length;
+
+ return 0;
+}
+
+static int get_prefix_info(sd_ndisc_router *rt, struct nd_opt_prefix_info **ret) {
+ struct nd_opt_prefix_info *ri;
+ size_t length;
+ int r;
+
+ assert(rt);
+ assert(ret);
+
+ r = sd_ndisc_router_option_is_type(rt, SD_NDISC_OPTION_PREFIX_INFORMATION);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return -EMEDIUMTYPE;
+
+ length = NDISC_ROUTER_OPTION_LENGTH(rt);
+ if (length != sizeof(struct nd_opt_prefix_info))
+ return -EBADMSG;
+
+ ri = (struct nd_opt_prefix_info*) ((uint8_t*) NDISC_ROUTER_RAW(rt) + rt->rindex);
+ if (ri->nd_opt_pi_prefix_len > 128)
+ return -EBADMSG;
+
+ *ret = ri;
+ return 0;
+}
+
+_public_ int sd_ndisc_router_prefix_get_valid_lifetime(sd_ndisc_router *rt, uint32_t *ret) {
+ struct nd_opt_prefix_info *ri;
+ int r;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ r = get_prefix_info(rt, &ri);
+ if (r < 0)
+ return r;
+
+ *ret = be32toh(ri->nd_opt_pi_valid_time);
+ return 0;
+}
+
+_public_ int sd_ndisc_router_prefix_get_preferred_lifetime(sd_ndisc_router *rt, uint32_t *ret) {
+ struct nd_opt_prefix_info *pi;
+ int r;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ r = get_prefix_info(rt, &pi);
+ if (r < 0)
+ return r;
+
+ *ret = be32toh(pi->nd_opt_pi_preferred_time);
+ return 0;
+}
+
+_public_ int sd_ndisc_router_prefix_get_flags(sd_ndisc_router *rt, uint8_t *ret) {
+ struct nd_opt_prefix_info *pi;
+ uint8_t flags;
+ int r;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ r = get_prefix_info(rt, &pi);
+ if (r < 0)
+ return r;
+
+ flags = pi->nd_opt_pi_flags_reserved;
+
+ if ((flags & ND_OPT_PI_FLAG_AUTO) && (pi->nd_opt_pi_prefix_len != 64)) {
+ log_ndisc("Invalid prefix length, ignoring prefix for stateless autoconfiguration.");
+ flags &= ~ND_OPT_PI_FLAG_AUTO;
+ }
+
+ *ret = flags;
+ return 0;
+}
+
+_public_ int sd_ndisc_router_prefix_get_address(sd_ndisc_router *rt, struct in6_addr *ret_addr) {
+ struct nd_opt_prefix_info *pi;
+ int r;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret_addr, -EINVAL);
+
+ r = get_prefix_info(rt, &pi);
+ if (r < 0)
+ return r;
+
+ *ret_addr = pi->nd_opt_pi_prefix;
+ return 0;
+}
+
+_public_ int sd_ndisc_router_prefix_get_prefixlen(sd_ndisc_router *rt, unsigned *ret) {
+ struct nd_opt_prefix_info *pi;
+ int r;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ r = get_prefix_info(rt, &pi);
+ if (r < 0)
+ return r;
+
+ if (pi->nd_opt_pi_prefix_len > 128)
+ return -EBADMSG;
+
+ *ret = pi->nd_opt_pi_prefix_len;
+ return 0;
+}
+
+static int get_route_info(sd_ndisc_router *rt, uint8_t **ret) {
+ uint8_t *ri;
+ size_t length;
+ int r;
+
+ assert(rt);
+ assert(ret);
+
+ r = sd_ndisc_router_option_is_type(rt, SD_NDISC_OPTION_ROUTE_INFORMATION);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return -EMEDIUMTYPE;
+
+ length = NDISC_ROUTER_OPTION_LENGTH(rt);
+ if (length < 1*8 || length > 3*8)
+ return -EBADMSG;
+
+ ri = (uint8_t*) NDISC_ROUTER_RAW(rt) + rt->rindex;
+
+ if (ri[2] > 128)
+ return -EBADMSG;
+
+ *ret = ri;
+ return 0;
+}
+
+_public_ int sd_ndisc_router_route_get_lifetime(sd_ndisc_router *rt, uint32_t *ret) {
+ uint8_t *ri;
+ int r;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ r = get_route_info(rt, &ri);
+ if (r < 0)
+ return r;
+
+ *ret = be32toh(*(uint32_t*) (ri + 4));
+ return 0;
+}
+
+_public_ int sd_ndisc_router_route_get_address(sd_ndisc_router *rt, struct in6_addr *ret_addr) {
+ uint8_t *ri;
+ int r;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret_addr, -EINVAL);
+
+ r = get_route_info(rt, &ri);
+ if (r < 0)
+ return r;
+
+ zero(*ret_addr);
+ memcpy(ret_addr, ri + 8, NDISC_ROUTER_OPTION_LENGTH(rt) - 8);
+
+ return 0;
+}
+
+_public_ int sd_ndisc_router_route_get_prefixlen(sd_ndisc_router *rt, unsigned *ret) {
+ uint8_t *ri;
+ int r;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ r = get_route_info(rt, &ri);
+ if (r < 0)
+ return r;
+
+ *ret = ri[2];
+ return 0;
+}
+
+_public_ int sd_ndisc_router_route_get_preference(sd_ndisc_router *rt, unsigned *ret) {
+ uint8_t *ri;
+ int r;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ r = get_route_info(rt, &ri);
+ if (r < 0)
+ return r;
+
+ *ret = (ri[3] >> 3) & 3;
+ if (!IN_SET(*ret, SD_NDISC_PREFERENCE_LOW, SD_NDISC_PREFERENCE_HIGH))
+ *ret = SD_NDISC_PREFERENCE_MEDIUM;
+
+ return 0;
+}
+
+static int get_rdnss_info(sd_ndisc_router *rt, uint8_t **ret) {
+ size_t length;
+ int r;
+
+ assert(rt);
+ assert(ret);
+
+ r = sd_ndisc_router_option_is_type(rt, SD_NDISC_OPTION_RDNSS);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return -EMEDIUMTYPE;
+
+ length = NDISC_ROUTER_OPTION_LENGTH(rt);
+ if (length < 3*8 || (length % (2*8)) != 1*8)
+ return -EBADMSG;
+
+ *ret = (uint8_t*) NDISC_ROUTER_RAW(rt) + rt->rindex;
+ return 0;
+}
+
+_public_ int sd_ndisc_router_rdnss_get_addresses(sd_ndisc_router *rt, const struct in6_addr **ret) {
+ uint8_t *ri;
+ int r;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ r = get_rdnss_info(rt, &ri);
+ if (r < 0)
+ return r;
+
+ *ret = (const struct in6_addr*) (ri + 8);
+ return (NDISC_ROUTER_OPTION_LENGTH(rt) - 8) / 16;
+}
+
+_public_ int sd_ndisc_router_rdnss_get_lifetime(sd_ndisc_router *rt, uint32_t *ret) {
+ uint8_t *ri;
+ int r;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ r = get_rdnss_info(rt, &ri);
+ if (r < 0)
+ return r;
+
+ *ret = be32toh(*(uint32_t*) (ri + 4));
+ return 0;
+}
+
+static int get_dnssl_info(sd_ndisc_router *rt, uint8_t **ret) {
+ size_t length;
+ int r;
+
+ assert(rt);
+ assert(ret);
+
+ r = sd_ndisc_router_option_is_type(rt, SD_NDISC_OPTION_DNSSL);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return -EMEDIUMTYPE;
+
+ length = NDISC_ROUTER_OPTION_LENGTH(rt);
+ if (length < 2*8)
+ return -EBADMSG;
+
+ *ret = (uint8_t*) NDISC_ROUTER_RAW(rt) + rt->rindex;
+ return 0;
+}
+
+_public_ int sd_ndisc_router_dnssl_get_domains(sd_ndisc_router *rt, char ***ret) {
+ _cleanup_strv_free_ char **l = NULL;
+ _cleanup_free_ char *e = NULL;
+ size_t allocated = 0, n = 0, left;
+ uint8_t *ri, *p;
+ bool first = true;
+ int r;
+ unsigned k = 0;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ r = get_dnssl_info(rt, &ri);
+ if (r < 0)
+ return r;
+
+ p = ri + 8;
+ left = NDISC_ROUTER_OPTION_LENGTH(rt) - 8;
+
+ for (;;) {
+ if (left == 0) {
+
+ if (n > 0) /* Not properly NUL terminated */
+ return -EBADMSG;
+
+ break;
+ }
+
+ if (*p == 0) {
+ /* Found NUL termination */
+
+ if (n > 0) {
+ _cleanup_free_ char *normalized = NULL;
+
+ e[n] = 0;
+ r = dns_name_normalize(e, 0, &normalized);
+ if (r < 0)
+ return r;
+
+ /* Ignore the root domain name or "localhost" and friends */
+ if (!is_localhost(normalized) &&
+ !dns_name_is_root(normalized)) {
+
+ if (strv_push(&l, normalized) < 0)
+ return -ENOMEM;
+
+ normalized = NULL;
+ k++;
+ }
+ }
+
+ n = 0;
+ first = true;
+ p++, left--;
+ continue;
+ }
+
+ /* Check for compression (which is not allowed) */
+ if (*p > 63)
+ return -EBADMSG;
+
+ if (1U + *p + 1U > left)
+ return -EBADMSG;
+
+ if (!GREEDY_REALLOC(e, allocated, n + !first + DNS_LABEL_ESCAPED_MAX + 1U))
+ return -ENOMEM;
+
+ if (first)
+ first = false;
+ else
+ e[n++] = '.';
+
+ r = dns_label_escape((char*) p+1, *p, e + n, DNS_LABEL_ESCAPED_MAX);
+ if (r < 0)
+ return r;
+
+ n += r;
+
+ left -= 1 + *p;
+ p += 1 + *p;
+ }
+
+ if (strv_isempty(l)) {
+ *ret = NULL;
+ return 0;
+ }
+
+ *ret = TAKE_PTR(l);
+
+ return k;
+}
+
+_public_ int sd_ndisc_router_dnssl_get_lifetime(sd_ndisc_router *rt, uint32_t *ret_sec) {
+ uint8_t *ri;
+ int r;
+
+ assert_return(rt, -EINVAL);
+ assert_return(ret_sec, -EINVAL);
+
+ r = get_dnssl_info(rt, &ri);
+ if (r < 0)
+ return r;
+
+ *ret_sec = be32toh(*(uint32_t*) (ri + 4));
+ return 0;
+}
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