Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 381 insertions, 0 deletions

diff --git a/src/libsystemd-network/sd-ndisc.c b/src/libsystemd-network/sd-ndisc.c
new file mode 100644
index 0000000..1beed5d
--- /dev/null
+++ b/src/libsystemd-network/sd-ndisc.c
@@ -0,0 +1,381 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/***
+  Copyright © 2014 Intel Corporation. All rights reserved.
+***/
+
+#include <netinet/icmp6.h>
+#include <netinet/in.h>
+
+#include "sd-ndisc.h"
+
+#include "alloc-util.h"
+#include "event-util.h"
+#include "fd-util.h"
+#include "icmp6-util.h"
+#include "in-addr-util.h"
+#include "memory-util.h"
+#include "ndisc-internal.h"
+#include "ndisc-router.h"
+#include "network-common.h"
+#include "random-util.h"
+#include "socket-util.h"
+#include "string-table.h"
+#include "string-util.h"
+
+#define NDISC_TIMEOUT_NO_RA_USEC (NDISC_ROUTER_SOLICITATION_INTERVAL * NDISC_MAX_ROUTER_SOLICITATIONS)
+
+static const char * const ndisc_event_table[_SD_NDISC_EVENT_MAX] = {
+        [SD_NDISC_EVENT_TIMEOUT] = "timeout",
+        [SD_NDISC_EVENT_ROUTER] = "router",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(ndisc_event, sd_ndisc_event_t);
+
+static void ndisc_callback(sd_ndisc *ndisc, sd_ndisc_event_t event, sd_ndisc_router *rt) {
+        assert(ndisc);
+        assert(event >= 0 && event < _SD_NDISC_EVENT_MAX);
+
+        if (!ndisc->callback)
+                return (void) log_ndisc(ndisc, "Received '%s' event.", ndisc_event_to_string(event));
+
+        log_ndisc(ndisc, "Invoking callback for '%s' event.", ndisc_event_to_string(event));
+        ndisc->callback(ndisc, event, rt, ndisc->userdata);
+}
+
+int sd_ndisc_set_callback(
+                sd_ndisc *nd,
+                sd_ndisc_callback_t callback,
+                void *userdata) {
+
+        assert_return(nd, -EINVAL);
+
+        nd->callback = callback;
+        nd->userdata = userdata;
+
+        return 0;
+}
+
+int sd_ndisc_set_ifindex(sd_ndisc *nd, int ifindex) {
+        assert_return(nd, -EINVAL);
+        assert_return(ifindex > 0, -EINVAL);
+        assert_return(nd->fd < 0, -EBUSY);
+
+        nd->ifindex = ifindex;
+        return 0;
+}
+
+int sd_ndisc_set_ifname(sd_ndisc *nd, const char *ifname) {
+        assert_return(nd, -EINVAL);
+        assert_return(ifname, -EINVAL);
+
+        if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE))
+                return -EINVAL;
+
+        return free_and_strdup(&nd->ifname, ifname);
+}
+
+int sd_ndisc_get_ifname(sd_ndisc *nd, const char **ret) {
+        int r;
+
+        assert_return(nd, -EINVAL);
+
+        r = get_ifname(nd->ifindex, &nd->ifname);
+        if (r < 0)
+                return r;
+
+        if (ret)
+                *ret = nd->ifname;
+
+        return 0;
+}
+
+int sd_ndisc_set_mac(sd_ndisc *nd, const struct ether_addr *mac_addr) {
+        assert_return(nd, -EINVAL);
+
+        if (mac_addr)
+                nd->mac_addr = *mac_addr;
+        else
+                zero(nd->mac_addr);
+
+        return 0;
+}
+
+int sd_ndisc_attach_event(sd_ndisc *nd, sd_event *event, int64_t priority) {
+        int r;
+
+        assert_return(nd, -EINVAL);
+        assert_return(nd->fd < 0, -EBUSY);
+        assert_return(!nd->event, -EBUSY);
+
+        if (event)
+                nd->event = sd_event_ref(event);
+        else {
+                r = sd_event_default(&nd->event);
+                if (r < 0)
+                        return 0;
+        }
+
+        nd->event_priority = priority;
+
+        return 0;
+}
+
+int sd_ndisc_detach_event(sd_ndisc *nd) {
+
+        assert_return(nd, -EINVAL);
+        assert_return(nd->fd < 0, -EBUSY);
+
+        nd->event = sd_event_unref(nd->event);
+        return 0;
+}
+
+sd_event *sd_ndisc_get_event(sd_ndisc *nd) {
+        assert_return(nd, NULL);
+
+        return nd->event;
+}
+
+static void ndisc_reset(sd_ndisc *nd) {
+        assert(nd);
+
+        (void) event_source_disable(nd->timeout_event_source);
+        (void) event_source_disable(nd->timeout_no_ra);
+        nd->retransmit_time = 0;
+        nd->recv_event_source = sd_event_source_disable_unref(nd->recv_event_source);
+        nd->fd = safe_close(nd->fd);
+}
+
+static sd_ndisc *ndisc_free(sd_ndisc *nd) {
+        assert(nd);
+
+        ndisc_reset(nd);
+
+        sd_event_source_unref(nd->timeout_event_source);
+        sd_event_source_unref(nd->timeout_no_ra);
+        sd_ndisc_detach_event(nd);
+
+        free(nd->ifname);
+        return mfree(nd);
+}
+
+DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_ndisc, sd_ndisc, ndisc_free);
+
+int sd_ndisc_new(sd_ndisc **ret) {
+        _cleanup_(sd_ndisc_unrefp) sd_ndisc *nd = NULL;
+
+        assert_return(ret, -EINVAL);
+
+        nd = new(sd_ndisc, 1);
+        if (!nd)
+                return -ENOMEM;
+
+        *nd = (sd_ndisc) {
+                .n_ref = 1,
+                .fd = -EBADF,
+        };
+
+        *ret = TAKE_PTR(nd);
+
+        return 0;
+}
+
+static int ndisc_handle_datagram(sd_ndisc *nd, sd_ndisc_router *rt) {
+        int r;
+
+        assert(nd);
+        assert(rt);
+
+        r = ndisc_router_parse(nd, rt);
+        if (r < 0)
+                return r;
+
+        log_ndisc(nd, "Received Router Advertisement: flags %s preference %s lifetime %s",
+                  rt->flags & ND_RA_FLAG_MANAGED ? "MANAGED" : rt->flags & ND_RA_FLAG_OTHER ? "OTHER" : "none",
+                  rt->preference == SD_NDISC_PREFERENCE_HIGH ? "high" : rt->preference == SD_NDISC_PREFERENCE_LOW ? "low" : "medium",
+                  FORMAT_TIMESPAN(rt->lifetime_usec, USEC_PER_SEC));
+
+        ndisc_callback(nd, SD_NDISC_EVENT_ROUTER, rt);
+        return 0;
+}
+
+static int ndisc_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        _cleanup_(sd_ndisc_router_unrefp) sd_ndisc_router *rt = NULL;
+        sd_ndisc *nd = ASSERT_PTR(userdata);
+        ssize_t buflen;
+        int r;
+
+        assert(s);
+        assert(nd->event);
+
+        buflen = next_datagram_size_fd(fd);
+        if (ERRNO_IS_NEG_TRANSIENT(buflen) || ERRNO_IS_NEG_DISCONNECT(buflen))
+                return 0;
+        if (buflen < 0) {
+                log_ndisc_errno(nd, buflen, "Failed to determine datagram size to read, ignoring: %m");
+                return 0;
+        }
+
+        rt = ndisc_router_new(buflen);
+        if (!rt)
+                return -ENOMEM;
+
+        r = icmp6_receive(fd, NDISC_ROUTER_RAW(rt), rt->raw_size, &rt->address, &rt->timestamp);
+        if (ERRNO_IS_NEG_TRANSIENT(r) || ERRNO_IS_NEG_DISCONNECT(r))
+                return 0;
+        if (r < 0)
+                switch (r) {
+                case -EADDRNOTAVAIL:
+                        log_ndisc(nd, "Received RA from neither link-local nor null address. Ignoring.");
+                        return 0;
+
+                case -EMULTIHOP:
+                        log_ndisc(nd, "Received RA with invalid hop limit. Ignoring.");
+                        return 0;
+
+                case -EPFNOSUPPORT:
+                        log_ndisc(nd, "Received invalid source address from ICMPv6 socket. Ignoring.");
+                        return 0;
+
+                default:
+                        log_ndisc_errno(nd, r, "Unexpected error while reading from ICMPv6, ignoring: %m");
+                        return 0;
+                }
+
+        /* The function icmp6_receive() accepts the null source address, but RFC 4861 Section 6.1.2 states
+         * that hosts MUST discard messages with the null source address. */
+        if (in6_addr_is_null(&rt->address))
+                log_ndisc(nd, "Received RA from null address. Ignoring.");
+
+        (void) event_source_disable(nd->timeout_event_source);
+        (void) ndisc_handle_datagram(nd, rt);
+        return 0;
+}
+
+static usec_t ndisc_timeout_compute_random(usec_t val) {
+        /* compute a time that is random within ±10% of the given value */
+        return val - val / 10 +
+                (random_u64() % (2 * USEC_PER_SEC)) * val / 10 / USEC_PER_SEC;
+}
+
+static int ndisc_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
+        sd_ndisc *nd = ASSERT_PTR(userdata);
+        usec_t time_now;
+        int r;
+
+        assert(s);
+        assert(nd->event);
+
+        assert_se(sd_event_now(nd->event, CLOCK_BOOTTIME, &time_now) >= 0);
+
+        if (!nd->retransmit_time)
+                nd->retransmit_time = ndisc_timeout_compute_random(NDISC_ROUTER_SOLICITATION_INTERVAL);
+        else {
+                if (nd->retransmit_time > NDISC_MAX_ROUTER_SOLICITATION_INTERVAL / 2)
+                        nd->retransmit_time = ndisc_timeout_compute_random(NDISC_MAX_ROUTER_SOLICITATION_INTERVAL);
+                else
+                        nd->retransmit_time += ndisc_timeout_compute_random(nd->retransmit_time);
+        }
+
+        r = event_reset_time(nd->event, &nd->timeout_event_source,
+                             CLOCK_BOOTTIME,
+                             time_now + nd->retransmit_time, 10 * USEC_PER_MSEC,
+                             ndisc_timeout, nd,
+                             nd->event_priority, "ndisc-timeout-no-ra", true);
+        if (r < 0)
+                goto fail;
+
+        r = icmp6_send_router_solicitation(nd->fd, &nd->mac_addr);
+        if (r < 0)
+                log_ndisc_errno(nd, r, "Failed to send Router Solicitation, next solicitation in %s, ignoring: %m",
+                                FORMAT_TIMESPAN(nd->retransmit_time, USEC_PER_SEC));
+        else
+                log_ndisc(nd, "Sent Router Solicitation, next solicitation in %s",
+                          FORMAT_TIMESPAN(nd->retransmit_time, USEC_PER_SEC));
+
+        return 0;
+
+fail:
+        (void) sd_ndisc_stop(nd);
+        return 0;
+}
+
+static int ndisc_timeout_no_ra(sd_event_source *s, uint64_t usec, void *userdata) {
+        sd_ndisc *nd = ASSERT_PTR(userdata);
+
+        assert(s);
+
+        log_ndisc(nd, "No RA received before link confirmation timeout");
+
+        (void) event_source_disable(nd->timeout_no_ra);
+        ndisc_callback(nd, SD_NDISC_EVENT_TIMEOUT, NULL);
+
+        return 0;
+}
+
+int sd_ndisc_stop(sd_ndisc *nd) {
+        if (!nd)
+                return 0;
+
+        if (nd->fd < 0)
+                return 0;
+
+        log_ndisc(nd, "Stopping IPv6 Router Solicitation client");
+
+        ndisc_reset(nd);
+        return 1;
+}
+
+int sd_ndisc_start(sd_ndisc *nd) {
+        int r;
+        usec_t time_now;
+
+        assert_return(nd, -EINVAL);
+        assert_return(nd->event, -EINVAL);
+        assert_return(nd->ifindex > 0, -EINVAL);
+
+        if (nd->fd >= 0)
+                return 0;
+
+        assert(!nd->recv_event_source);
+
+        r = sd_event_now(nd->event, CLOCK_BOOTTIME, &time_now);
+        if (r < 0)
+                goto fail;
+
+        nd->fd = icmp6_bind_router_solicitation(nd->ifindex);
+        if (nd->fd < 0)
+                return nd->fd;
+
+        r = sd_event_add_io(nd->event, &nd->recv_event_source, nd->fd, EPOLLIN, ndisc_recv, nd);
+        if (r < 0)
+                goto fail;
+
+        r = sd_event_source_set_priority(nd->recv_event_source, nd->event_priority);
+        if (r < 0)
+                goto fail;
+
+        (void) sd_event_source_set_description(nd->recv_event_source, "ndisc-receive-message");
+
+        r = event_reset_time(nd->event, &nd->timeout_event_source,
+                             CLOCK_BOOTTIME,
+                             time_now + USEC_PER_SEC / 2, 1 * USEC_PER_SEC, /* See RFC 8415 sec. 18.2.1 */
+                             ndisc_timeout, nd,
+                             nd->event_priority, "ndisc-timeout", true);
+        if (r < 0)
+                goto fail;
+
+        r = event_reset_time(nd->event, &nd->timeout_no_ra,
+                             CLOCK_BOOTTIME,
+                             time_now + NDISC_TIMEOUT_NO_RA_USEC, 10 * USEC_PER_MSEC,
+                             ndisc_timeout_no_ra, nd,
+                             nd->event_priority, "ndisc-timeout-no-ra", true);
+        if (r < 0)
+                goto fail;
+
+        log_ndisc(nd, "Started IPv6 Router Solicitation client");
+        return 1;
+
+fail:
+        ndisc_reset(nd);
+        return r;
+}