Adding upstream version 256.upstream/256

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

1 files changed, 513 insertions, 0 deletions

diff --git a/src/libsystemd-network/sd-dhcp-server-lease.c b/src/libsystemd-network/sd-dhcp-server-lease.c
new file mode 100644
index 0000000..2f84d51
--- /dev/null
+++ b/src/libsystemd-network/sd-dhcp-server-lease.c
@@ -0,0 +1,513 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "dhcp-server-lease-internal.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "mkdir.h"
+#include "tmpfile-util.h"
+
+static sd_dhcp_server_lease* dhcp_server_lease_free(sd_dhcp_server_lease *lease) {
+        if (!lease)
+                return NULL;
+
+        if (lease->server) {
+                hashmap_remove_value(lease->server->bound_leases_by_address, UINT32_TO_PTR(lease->address), lease);
+                hashmap_remove_value(lease->server->bound_leases_by_client_id, &lease->client_id, lease);
+                hashmap_remove_value(lease->server->static_leases_by_address, UINT32_TO_PTR(lease->address), lease);
+                hashmap_remove_value(lease->server->static_leases_by_client_id, &lease->client_id, lease);
+        }
+
+        free(lease->hostname);
+        return mfree(lease);
+}
+
+DEFINE_TRIVIAL_REF_UNREF_FUNC(sd_dhcp_server_lease, sd_dhcp_server_lease, dhcp_server_lease_free);
+
+DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(
+        dhcp_server_lease_hash_ops,
+        sd_dhcp_client_id,
+        client_id_hash_func,
+        client_id_compare_func,
+        sd_dhcp_server_lease,
+        sd_dhcp_server_lease_unref);
+
+int dhcp_server_put_lease(sd_dhcp_server *server, sd_dhcp_server_lease *lease, bool is_static) {
+        int r;
+
+        assert(server);
+        assert(lease);
+
+        lease->server = server; /* This must be set before hashmap_put(). */
+
+        r = hashmap_ensure_put(is_static ? &server->static_leases_by_client_id : &server->bound_leases_by_client_id,
+                               &dhcp_server_lease_hash_ops, &lease->client_id, lease);
+        if (r < 0)
+                return r;
+
+        r = hashmap_ensure_put(is_static ? &server->static_leases_by_address : &server->bound_leases_by_address,
+                               NULL, UINT32_TO_PTR(lease->address), lease);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+int dhcp_server_set_lease(sd_dhcp_server *server, be32_t address, DHCPRequest *req, usec_t expiration) {
+        _cleanup_(sd_dhcp_server_lease_unrefp) sd_dhcp_server_lease *lease = NULL;
+        int r;
+
+        assert(server);
+        assert(address != 0);
+        assert(req);
+        assert(expiration != 0);
+
+        /* If a lease for the host already exists, update it. */
+        lease = hashmap_get(server->bound_leases_by_client_id, &req->client_id);
+        if (lease) {
+                if (lease->address != address) {
+                        hashmap_remove_value(server->bound_leases_by_address, UINT32_TO_PTR(lease->address), lease);
+                        lease->address = address;
+
+                        r = hashmap_ensure_put(&server->bound_leases_by_address, NULL, UINT32_TO_PTR(lease->address), lease);
+                        if (r < 0)
+                                return r;
+                }
+
+                lease->expiration = expiration;
+
+                TAKE_PTR(lease);
+                return 0;
+        }
+
+        /* Otherwise, add a new lease. */
+
+        lease = new(sd_dhcp_server_lease, 1);
+        if (!lease)
+                return -ENOMEM;
+
+        *lease = (sd_dhcp_server_lease) {
+                .n_ref = 1,
+                .address = address,
+                .client_id = req->client_id,
+                .htype = req->message->htype,
+                .hlen = req->message->hlen,
+                .gateway = req->message->giaddr,
+                .expiration = expiration,
+        };
+
+        memcpy(lease->chaddr, req->message->chaddr, req->message->hlen);
+
+        if (req->hostname) {
+                lease->hostname = strdup(req->hostname);
+                if (!lease->hostname)
+                        return -ENOMEM;
+        }
+
+        r = dhcp_server_put_lease(server, lease, /* is_static = */ false);
+        if (r < 0)
+                return r;
+
+        TAKE_PTR(lease);
+        return 0;
+}
+
+int dhcp_server_cleanup_expired_leases(sd_dhcp_server *server) {
+        sd_dhcp_server_lease *lease;
+        usec_t time_now;
+        int r;
+
+        assert(server);
+
+        r = sd_event_now(server->event, CLOCK_BOOTTIME, &time_now);
+        if (r < 0)
+                return r;
+
+        HASHMAP_FOREACH(lease, server->bound_leases_by_client_id)
+                if (lease->expiration < time_now) {
+                        log_dhcp_server(server, "CLEAN (0x%x)", be32toh(lease->address));
+                        sd_dhcp_server_lease_unref(lease);
+                }
+
+        return 0;
+}
+
+sd_dhcp_server_lease* dhcp_server_get_static_lease(sd_dhcp_server *server, const DHCPRequest *req) {
+        sd_dhcp_server_lease *static_lease;
+        sd_dhcp_client_id client_id;
+
+        assert(server);
+        assert(req);
+
+        static_lease = hashmap_get(server->static_leases_by_client_id, &req->client_id);
+        if (static_lease)
+                goto verify;
+
+        /* when no lease is found based on the client id fall back to chaddr */
+        if (!client_id_data_size_is_valid(req->message->hlen))
+                return NULL;
+
+        if (sd_dhcp_client_id_set(&client_id, /* type = */ 1, req->message->chaddr, req->message->hlen) < 0)
+                return NULL;
+
+        static_lease = hashmap_get(server->static_leases_by_client_id, &client_id);
+        if (!static_lease)
+                return NULL;
+
+verify:
+        /* Check if the address is in the same subnet. */
+        if ((static_lease->address & server->netmask) != server->subnet)
+                return NULL;
+
+        /* Check if the address is different from the server address. */
+        if (static_lease->address == server->address)
+                return NULL;
+
+        return static_lease;
+}
+
+int sd_dhcp_server_set_static_lease(
+                sd_dhcp_server *server,
+                const struct in_addr *address,
+                uint8_t *client_id_raw,
+                size_t client_id_size) {
+
+        _cleanup_(sd_dhcp_server_lease_unrefp) sd_dhcp_server_lease *lease = NULL;
+        sd_dhcp_client_id client_id;
+        int r;
+
+        assert_return(server, -EINVAL);
+        assert_return(client_id_raw, -EINVAL);
+        assert_return(client_id_size_is_valid(client_id_size), -EINVAL);
+        assert_return(!sd_dhcp_server_is_running(server), -EBUSY);
+
+        r = sd_dhcp_client_id_set_raw(&client_id, client_id_raw, client_id_size);
+        if (r < 0)
+                return r;
+
+        /* Static lease with an empty or omitted address is a valid entry,
+         * the server removes any static lease with the specified mac address. */
+        if (!address || address->s_addr == 0) {
+                sd_dhcp_server_lease_unref(hashmap_get(server->static_leases_by_client_id, &client_id));
+                return 0;
+        }
+
+        lease = new(sd_dhcp_server_lease, 1);
+        if (!lease)
+                return -ENOMEM;
+
+        *lease = (sd_dhcp_server_lease) {
+                .n_ref = 1,
+                .address = address->s_addr,
+                .client_id = client_id,
+        };
+
+        r = dhcp_server_put_lease(server, lease, /* is_static = */ true);
+        if (r < 0)
+                return r;
+
+        TAKE_PTR(lease);
+        return 0;
+}
+
+static int dhcp_server_lease_append_json(sd_dhcp_server_lease *lease, JsonVariant **ret) {
+        assert(lease);
+        assert(ret);
+
+        return json_build(ret,
+                        JSON_BUILD_OBJECT(
+                                 JSON_BUILD_PAIR_BYTE_ARRAY("ClientId", lease->client_id.raw, lease->client_id.size),
+                                 JSON_BUILD_PAIR_IN4_ADDR_NON_NULL("Address", &(struct in_addr) { .s_addr = lease->address }),
+                                 JSON_BUILD_PAIR_STRING_NON_EMPTY("Hostname", lease->hostname)));
+}
+
+int dhcp_server_bound_leases_append_json(sd_dhcp_server *server, JsonVariant **v) {
+        _cleanup_(json_variant_unrefp) JsonVariant *array = NULL;
+        sd_dhcp_server_lease *lease;
+        usec_t now_b, now_r;
+        int r;
+
+        assert(server);
+        assert(v);
+
+        r = sd_event_now(server->event, CLOCK_BOOTTIME, &now_b);
+        if (r < 0)
+                return r;
+
+        r = sd_event_now(server->event, CLOCK_REALTIME, &now_r);
+        if (r < 0)
+                return r;
+
+        HASHMAP_FOREACH(lease, server->bound_leases_by_client_id) {
+                _cleanup_(json_variant_unrefp) JsonVariant *w = NULL;
+
+                r = dhcp_server_lease_append_json(lease, &w);
+                if (r < 0)
+                        return r;
+
+                usec_t exp_r = map_clock_usec_raw(lease->expiration, now_b, now_r);
+
+                r = json_variant_merge_objectb(&w,
+                                 JSON_BUILD_OBJECT(
+                                         JSON_BUILD_PAIR_UNSIGNED("ExpirationUSec", lease->expiration),
+                                         JSON_BUILD_PAIR_UNSIGNED("ExpirationRealtimeUSec", exp_r)));
+                if (r < 0)
+                        return r;
+
+                r = json_variant_append_array(&array, w);
+                if (r < 0)
+                        return r;
+        }
+
+        return json_variant_set_field_non_null(v, "Leases", array);
+}
+
+int dhcp_server_static_leases_append_json(sd_dhcp_server *server, JsonVariant **v) {
+        _cleanup_(json_variant_unrefp) JsonVariant *array = NULL;
+        sd_dhcp_server_lease *lease;
+        int r;
+
+        assert(server);
+        assert(v);
+
+        HASHMAP_FOREACH(lease, server->static_leases_by_client_id) {
+                _cleanup_(json_variant_unrefp) JsonVariant *w = NULL;
+
+                r = dhcp_server_lease_append_json(lease, &w);
+                if (r < 0)
+                        return r;
+
+                r = json_variant_append_array(&array, w);
+                if (r < 0)
+                        return r;
+        }
+
+        return json_variant_set_field_non_null(v, "StaticLeases", array);
+}
+
+int dhcp_server_save_leases(sd_dhcp_server *server) {
+        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+        _cleanup_free_ char *temp_path = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        sd_id128_t boot_id;
+        int r;
+
+        assert(server);
+
+        if (!server->lease_file)
+                return 0;
+
+        if (hashmap_isempty(server->bound_leases_by_client_id)) {
+                if (unlink(server->lease_file) < 0 && errno != ENOENT)
+                        return -errno;
+
+                return 0;
+        }
+
+        r = sd_id128_get_boot(&boot_id);
+        if (r < 0)
+                return r;
+
+        r = json_build(&v, JSON_BUILD_OBJECT(
+                                JSON_BUILD_PAIR_ID128("BootID", boot_id),
+                                JSON_BUILD_PAIR_IN4_ADDR("Address", &(struct in_addr) { .s_addr = server->address }),
+                                JSON_BUILD_PAIR_UNSIGNED("PrefixLength",
+                                        in4_addr_netmask_to_prefixlen(&(struct in_addr) { .s_addr = server->netmask }))));
+        if (r < 0)
+                return r;
+
+        r = dhcp_server_bound_leases_append_json(server, &v);
+        if (r < 0)
+                return r;
+
+        r = mkdirat_parents(server->lease_dir_fd, server->lease_file, 0755);
+        if (r < 0)
+                return r;
+
+        r = fopen_temporary_at(server->lease_dir_fd, server->lease_file, &f, &temp_path);
+        if (r < 0)
+                return r;
+
+        (void) fchmod(fileno(f), 0644);
+
+        r = json_variant_dump(v, JSON_FORMAT_NEWLINE | JSON_FORMAT_FLUSH, f, /* prefix = */ NULL);
+        if (r < 0)
+                goto failure;
+
+        r = conservative_renameat(server->lease_dir_fd, temp_path, server->lease_dir_fd, server->lease_file);
+        if (r < 0)
+                goto failure;
+
+        return 0;
+
+failure:
+        (void) unlinkat(server->lease_dir_fd, temp_path, /* flags = */ 0);
+        return r;
+}
+
+static int json_dispatch_dhcp_lease(sd_dhcp_server *server, JsonVariant *v, bool use_boottime) {
+        static const JsonDispatch dispatch_table_boottime[] = {
+                { "ClientId",               JSON_VARIANT_ARRAY,         json_dispatch_client_id, offsetof(sd_dhcp_server_lease, client_id),  JSON_MANDATORY },
+                { "Address",                JSON_VARIANT_ARRAY,         json_dispatch_in_addr,   offsetof(sd_dhcp_server_lease, address),    JSON_MANDATORY },
+                { "Hostname",               JSON_VARIANT_STRING,        json_dispatch_string,    offsetof(sd_dhcp_server_lease, hostname),   0              },
+                { "ExpirationUSec",         _JSON_VARIANT_TYPE_INVALID, json_dispatch_uint64,    offsetof(sd_dhcp_server_lease, expiration), JSON_MANDATORY },
+                { "ExpirationRealtimeUSec", _JSON_VARIANT_TYPE_INVALID, NULL,                    0,                                          JSON_MANDATORY },
+                {}
+        }, dispatch_table_realtime[] = {
+                { "ClientId",               JSON_VARIANT_ARRAY,         json_dispatch_client_id, offsetof(sd_dhcp_server_lease, client_id),  JSON_MANDATORY },
+                { "Address",                JSON_VARIANT_ARRAY,         json_dispatch_in_addr,   offsetof(sd_dhcp_server_lease, address),    JSON_MANDATORY },
+                { "Hostname",               JSON_VARIANT_STRING,        json_dispatch_string,    offsetof(sd_dhcp_server_lease, hostname),   0              },
+                { "ExpirationUSec",         _JSON_VARIANT_TYPE_INVALID, NULL,                    0,                                          JSON_MANDATORY },
+                { "ExpirationRealtimeUSec", _JSON_VARIANT_TYPE_INVALID, json_dispatch_uint64,    offsetof(sd_dhcp_server_lease, expiration), JSON_MANDATORY },
+                {}
+        };
+
+        _cleanup_(sd_dhcp_server_lease_unrefp) sd_dhcp_server_lease *lease = NULL;
+        usec_t now_b;
+        int r;
+
+        assert(server);
+        assert(v);
+
+        lease = new(sd_dhcp_server_lease, 1);
+        if (!lease)
+                return -ENOMEM;
+
+        *lease = (sd_dhcp_server_lease) {
+                .n_ref = 1,
+        };
+
+        r = json_dispatch(v, use_boottime ? dispatch_table_boottime : dispatch_table_realtime, JSON_ALLOW_EXTENSIONS, lease);
+        if (r < 0)
+                return r;
+
+        r = sd_event_now(server->event, CLOCK_BOOTTIME, &now_b);
+        if (r < 0)
+                return r;
+
+        if (use_boottime) {
+                if (lease->expiration < now_b)
+                        return 0; /* already expired */
+        } else {
+                usec_t now_r;
+
+                r = sd_event_now(server->event, CLOCK_REALTIME, &now_r);
+                if (r < 0)
+                        return r;
+
+                if (lease->expiration < now_r)
+                        return 0; /* already expired */
+
+                lease->expiration = map_clock_usec_raw(lease->expiration, now_r, now_b);
+        }
+
+        r = dhcp_server_put_lease(server, lease, /* is_static = */ false);
+        if (r == -EEXIST)
+                return 0;
+        if (r < 0)
+                return r;
+
+        TAKE_PTR(lease);
+        return 0;
+}
+
+typedef struct SavedInfo {
+        sd_id128_t boot_id;
+        struct in_addr address;
+        uint8_t prefixlen;
+        JsonVariant *leases;
+} SavedInfo;
+
+static void saved_info_done(SavedInfo *info) {
+        if (!info)
+                return;
+
+        json_variant_unref(info->leases);
+}
+
+static int load_leases_file(int dir_fd, const char *path, SavedInfo *ret) {
+        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+        int r;
+
+        assert(dir_fd >= 0 || dir_fd == AT_FDCWD);
+        assert(path);
+        assert(ret);
+
+        r = json_parse_file_at(
+                        /* f = */ NULL,
+                        dir_fd,
+                        path,
+                        /* flags = */ 0,
+                        &v,
+                        /* ret_line = */ NULL,
+                        /* ret_column = */ NULL);
+        if (r < 0)
+                return r;
+
+        static const JsonDispatch dispatch_lease_file_table[] = {
+                { "BootID",       JSON_VARIANT_STRING,        json_dispatch_id128,   offsetof(SavedInfo, boot_id),   JSON_MANDATORY },
+                { "Address",      JSON_VARIANT_ARRAY,         json_dispatch_in_addr, offsetof(SavedInfo, address),   JSON_MANDATORY },
+                { "PrefixLength", _JSON_VARIANT_TYPE_INVALID, json_dispatch_uint8,   offsetof(SavedInfo, prefixlen), JSON_MANDATORY },
+                { "Leases",       JSON_VARIANT_ARRAY,         json_dispatch_variant, offsetof(SavedInfo, leases),    JSON_MANDATORY },
+                {}
+        };
+
+        return json_dispatch(v, dispatch_lease_file_table, JSON_ALLOW_EXTENSIONS, ret);
+}
+
+int dhcp_server_load_leases(sd_dhcp_server *server) {
+        _cleanup_(saved_info_done) SavedInfo info = {};
+        sd_id128_t boot_id;
+        size_t n, m;
+        int r;
+
+        assert(server);
+        assert(server->event);
+
+        if (!server->lease_file)
+                return 0;
+
+        r = load_leases_file(server->lease_dir_fd, server->lease_file, &info);
+        if (r == -ENOENT)
+                return 0;
+        if (r < 0)
+                return r;
+
+        r = sd_id128_get_boot(&boot_id);
+        if (r < 0)
+                return r;
+
+        n = hashmap_size(server->bound_leases_by_client_id);
+
+        JsonVariant *i;
+        JSON_VARIANT_ARRAY_FOREACH(i, info.leases)
+                RET_GATHER(r, json_dispatch_dhcp_lease(server, i, /* use_boottime = */ sd_id128_equal(info.boot_id, boot_id)));
+
+        m = hashmap_size(server->bound_leases_by_client_id);
+        assert(m >= n);
+        log_dhcp_server(server, "Loaded %zu lease(s) from %s.", m - n, server->lease_file);
+
+        return r;
+}
+
+int dhcp_server_leases_file_get_server_address(
+                int dir_fd,
+                const char *path,
+                struct in_addr *ret_address,
+                uint8_t *ret_prefixlen) {
+
+        _cleanup_(saved_info_done) SavedInfo info = {};
+        int r;
+
+        if (!ret_address && !ret_prefixlen)
+                return 0;
+
+        r = load_leases_file(dir_fd, path, &info);
+        if (r < 0)
+                return r;
+
+        if (ret_address)
+                *ret_address = info.address;
+        if (ret_prefixlen)
+                *ret_prefixlen = info.prefixlen;
+        return 0;
+}