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-rw-r--r--src/libsystemd-network/sd-ipv4ll.c366
1 files changed, 366 insertions, 0 deletions
diff --git a/src/libsystemd-network/sd-ipv4ll.c b/src/libsystemd-network/sd-ipv4ll.c
new file mode 100644
index 0000000..4b0fac3
--- /dev/null
+++ b/src/libsystemd-network/sd-ipv4ll.c
@@ -0,0 +1,366 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/***
+ Copyright © 2014 Axis Communications AB. All rights reserved.
+***/
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "sd-id128.h"
+#include "sd-ipv4acd.h"
+#include "sd-ipv4ll.h"
+
+#include "alloc-util.h"
+#include "ether-addr-util.h"
+#include "in-addr-util.h"
+#include "network-common.h"
+#include "random-util.h"
+#include "siphash24.h"
+#include "sparse-endian.h"
+#include "string-util.h"
+#include "util.h"
+
+#define IPV4LL_NETWORK UINT32_C(0xA9FE0000)
+#define IPV4LL_NETMASK UINT32_C(0xFFFF0000)
+
+#define IPV4LL_DONT_DESTROY(ll) \
+ _cleanup_(sd_ipv4ll_unrefp) _unused_ sd_ipv4ll *_dont_destroy_##ll = sd_ipv4ll_ref(ll)
+
+struct sd_ipv4ll {
+ unsigned n_ref;
+
+ sd_ipv4acd *acd;
+
+ be32_t address; /* the address pushed to ACD */
+ struct ether_addr mac;
+
+ struct {
+ le64_t value;
+ le64_t generation;
+ } seed;
+ bool seed_set;
+
+ /* External */
+ be32_t claimed_address;
+
+ sd_ipv4ll_callback_t callback;
+ void *userdata;
+
+ sd_ipv4ll_check_mac_callback_t check_mac_callback;
+ void *check_mac_userdata;
+};
+
+#define log_ipv4ll_errno(ll, error, fmt, ...) \
+ log_interface_prefix_full_errno( \
+ "IPv4LL: ", \
+ sd_ipv4ll, ll, \
+ error, fmt, ##__VA_ARGS__)
+#define log_ipv4ll(ll, fmt, ...) \
+ log_interface_prefix_full_errno_zerook( \
+ "IPv4LL: ", \
+ sd_ipv4ll, ll, \
+ 0, fmt, ##__VA_ARGS__)
+
+static void ipv4ll_on_acd(sd_ipv4acd *acd, int event, void *userdata);
+static int ipv4ll_check_mac(sd_ipv4acd *acd, const struct ether_addr *mac, void *userdata);
+
+static sd_ipv4ll *ipv4ll_free(sd_ipv4ll *ll) {
+ assert(ll);
+
+ sd_ipv4acd_unref(ll->acd);
+ return mfree(ll);
+}
+
+DEFINE_TRIVIAL_REF_UNREF_FUNC(sd_ipv4ll, sd_ipv4ll, ipv4ll_free);
+
+int sd_ipv4ll_new(sd_ipv4ll **ret) {
+ _cleanup_(sd_ipv4ll_unrefp) sd_ipv4ll *ll = NULL;
+ int r;
+
+ assert_return(ret, -EINVAL);
+
+ ll = new0(sd_ipv4ll, 1);
+ if (!ll)
+ return -ENOMEM;
+
+ ll->n_ref = 1;
+
+ r = sd_ipv4acd_new(&ll->acd);
+ if (r < 0)
+ return r;
+
+ r = sd_ipv4acd_set_callback(ll->acd, ipv4ll_on_acd, ll);
+ if (r < 0)
+ return r;
+
+ r = sd_ipv4acd_set_check_mac_callback(ll->acd, ipv4ll_check_mac, ll);
+ if (r < 0)
+ return r;
+
+ *ret = TAKE_PTR(ll);
+
+ return 0;
+}
+
+int sd_ipv4ll_stop(sd_ipv4ll *ll) {
+ if (!ll)
+ return 0;
+
+ return sd_ipv4acd_stop(ll->acd);
+}
+
+int sd_ipv4ll_set_ifindex(sd_ipv4ll *ll, int ifindex) {
+ assert_return(ll, -EINVAL);
+ assert_return(ifindex > 0, -EINVAL);
+ assert_return(sd_ipv4ll_is_running(ll) == 0, -EBUSY);
+
+ return sd_ipv4acd_set_ifindex(ll->acd, ifindex);
+}
+
+int sd_ipv4ll_get_ifindex(sd_ipv4ll *ll) {
+ if (!ll)
+ return -EINVAL;
+
+ return sd_ipv4acd_get_ifindex(ll->acd);
+}
+
+int sd_ipv4ll_set_ifname(sd_ipv4ll *ll, const char *ifname) {
+ assert_return(ll, -EINVAL);
+ assert_return(ifname, -EINVAL);
+
+ return sd_ipv4acd_set_ifname(ll->acd, ifname);
+}
+
+int sd_ipv4ll_get_ifname(sd_ipv4ll *ll, const char **ret) {
+ assert_return(ll, -EINVAL);
+
+ return sd_ipv4acd_get_ifname(ll->acd, ret);
+}
+
+int sd_ipv4ll_set_mac(sd_ipv4ll *ll, const struct ether_addr *addr) {
+ int r;
+
+ assert_return(ll, -EINVAL);
+ assert_return(addr, -EINVAL);
+ assert_return(!ether_addr_is_null(addr), -EINVAL);
+
+ r = sd_ipv4acd_set_mac(ll->acd, addr);
+ if (r < 0)
+ return r;
+
+ ll->mac = *addr;
+ return 0;
+}
+
+int sd_ipv4ll_detach_event(sd_ipv4ll *ll) {
+ assert_return(ll, -EINVAL);
+
+ return sd_ipv4acd_detach_event(ll->acd);
+}
+
+int sd_ipv4ll_attach_event(sd_ipv4ll *ll, sd_event *event, int64_t priority) {
+ assert_return(ll, -EINVAL);
+
+ return sd_ipv4acd_attach_event(ll->acd, event, priority);
+}
+
+int sd_ipv4ll_set_callback(sd_ipv4ll *ll, sd_ipv4ll_callback_t cb, void *userdata) {
+ assert_return(ll, -EINVAL);
+
+ ll->callback = cb;
+ ll->userdata = userdata;
+
+ return 0;
+}
+
+int sd_ipv4ll_set_check_mac_callback(sd_ipv4ll *ll, sd_ipv4ll_check_mac_callback_t cb, void *userdata) {
+ assert_return(ll, -EINVAL);
+
+ ll->check_mac_callback = cb;
+ ll->check_mac_userdata = userdata;
+
+ return 0;
+}
+
+int sd_ipv4ll_get_address(sd_ipv4ll *ll, struct in_addr *address) {
+ assert_return(ll, -EINVAL);
+ assert_return(address, -EINVAL);
+
+ if (ll->claimed_address == 0)
+ return -ENOENT;
+
+ address->s_addr = ll->claimed_address;
+
+ return 0;
+}
+
+int sd_ipv4ll_set_address_seed(sd_ipv4ll *ll, uint64_t seed) {
+ assert_return(ll, -EINVAL);
+ assert_return(sd_ipv4ll_is_running(ll) == 0, -EBUSY);
+
+ ll->seed.value = htole64(seed);
+ ll->seed_set = true;
+
+ return 0;
+}
+
+int sd_ipv4ll_is_running(sd_ipv4ll *ll) {
+ assert_return(ll, false);
+
+ return sd_ipv4acd_is_running(ll->acd);
+}
+
+int sd_ipv4ll_set_address(sd_ipv4ll *ll, const struct in_addr *address) {
+ int r;
+
+ assert_return(ll, -EINVAL);
+ assert_return(address, -EINVAL);
+ assert_return(in4_addr_is_link_local_dynamic(address), -EINVAL);
+
+ r = sd_ipv4acd_set_address(ll->acd, address);
+ if (r < 0)
+ return r;
+
+ ll->address = address->s_addr;
+
+ return 0;
+}
+
+#define PICK_HASH_KEY SD_ID128_MAKE(15,ac,82,a6,d6,3f,49,78,98,77,5d,0c,69,02,94,0b)
+
+static int ipv4ll_pick_address(sd_ipv4ll *ll) {
+ be32_t addr;
+
+ assert(ll);
+
+ do {
+ uint64_t h;
+
+ h = siphash24(&ll->seed, sizeof(ll->seed), PICK_HASH_KEY.bytes);
+
+ /* Increase the generation counter by one */
+ ll->seed.generation = htole64(le64toh(ll->seed.generation) + 1);
+
+ addr = htobe32((h & UINT32_C(0x0000FFFF)) | IPV4LL_NETWORK);
+ } while (addr == ll->address ||
+ IN_SET(be32toh(addr) & 0x0000FF00U, 0x0000U, 0xFF00U));
+
+ log_ipv4ll(ll, "Picked new IP address %s.", IN4_ADDR_TO_STRING((const struct in_addr*) &addr));
+
+ return sd_ipv4ll_set_address(ll, &(struct in_addr) { addr });
+}
+
+#define MAC_HASH_KEY SD_ID128_MAKE(df,04,22,98,3f,ad,14,52,f9,87,2e,d1,9c,70,e2,f2)
+
+static int ipv4ll_start_internal(sd_ipv4ll *ll, bool reset_generation) {
+ int r;
+ bool picked_address = false;
+
+ assert_return(ll, -EINVAL);
+ assert_return(!ether_addr_is_null(&ll->mac), -EINVAL);
+
+ /* If no random seed is set, generate some from the MAC address */
+ if (!ll->seed_set)
+ ll->seed.value = htole64(siphash24(ll->mac.ether_addr_octet, ETH_ALEN, MAC_HASH_KEY.bytes));
+
+ if (reset_generation)
+ ll->seed.generation = 0;
+
+ if (ll->address == 0) {
+ r = ipv4ll_pick_address(ll);
+ if (r < 0)
+ return r;
+
+ picked_address = true;
+ }
+
+ r = sd_ipv4acd_start(ll->acd, reset_generation);
+ if (r < 0) {
+
+ /* We couldn't start? If so, let's forget the picked address again, the user might make a change and
+ * retry, and we want the new data to take effect when picking an address. */
+ if (picked_address)
+ ll->address = 0;
+
+ return r;
+ }
+
+ return 1;
+}
+
+int sd_ipv4ll_start(sd_ipv4ll *ll) {
+ assert_return(ll, -EINVAL);
+
+ if (sd_ipv4ll_is_running(ll))
+ return 0;
+
+ return ipv4ll_start_internal(ll, true);
+}
+
+int sd_ipv4ll_restart(sd_ipv4ll *ll) {
+ ll->address = 0;
+
+ return ipv4ll_start_internal(ll, false);
+}
+
+static void ipv4ll_client_notify(sd_ipv4ll *ll, int event) {
+ assert(ll);
+
+ if (ll->callback)
+ ll->callback(ll, event, ll->userdata);
+}
+
+void ipv4ll_on_acd(sd_ipv4acd *acd, int event, void *userdata) {
+ sd_ipv4ll *ll = ASSERT_PTR(userdata);
+ IPV4LL_DONT_DESTROY(ll);
+ int r;
+
+ assert(acd);
+
+ switch (event) {
+
+ case SD_IPV4ACD_EVENT_STOP:
+ ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_STOP);
+ ll->claimed_address = 0;
+ break;
+
+ case SD_IPV4ACD_EVENT_BIND:
+ ll->claimed_address = ll->address;
+ ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_BIND);
+ break;
+
+ case SD_IPV4ACD_EVENT_CONFLICT:
+ /* if an address was already bound we must call up to the
+ user to handle this, otherwise we just try again */
+ if (ll->claimed_address != 0) {
+ ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_CONFLICT);
+
+ ll->claimed_address = 0;
+ } else {
+ r = sd_ipv4ll_restart(ll);
+ if (r < 0)
+ goto error;
+ }
+
+ break;
+
+ default:
+ assert_not_reached();
+ }
+
+ return;
+
+error:
+ ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_STOP);
+}
+
+static int ipv4ll_check_mac(sd_ipv4acd *acd, const struct ether_addr *mac, void *userdata) {
+ sd_ipv4ll *ll = ASSERT_PTR(userdata);
+
+ if (ll->check_mac_callback)
+ return ll->check_mac_callback(ll, mac, ll->check_mac_userdata);
+
+ return 0;
+}
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