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-rw-r--r--src/libsystemd-network/dhcp-identifier.c209
1 files changed, 209 insertions, 0 deletions
diff --git a/src/libsystemd-network/dhcp-identifier.c b/src/libsystemd-network/dhcp-identifier.c
new file mode 100644
index 0000000..04bf64c
--- /dev/null
+++ b/src/libsystemd-network/dhcp-identifier.c
@@ -0,0 +1,209 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <linux/if_infiniband.h>
+#include <net/if_arp.h>
+
+#include "sd-device.h"
+#include "sd-id128.h"
+
+#include "dhcp-identifier.h"
+#include "dhcp6-protocol.h"
+#include "network-internal.h"
+#include "siphash24.h"
+#include "sparse-endian.h"
+#include "stdio-util.h"
+#include "virt.h"
+
+#define SYSTEMD_PEN 43793
+#define HASH_KEY SD_ID128_MAKE(80,11,8c,c2,fe,4a,03,ee,3e,d6,0c,6f,36,39,14,09)
+#define APPLICATION_ID SD_ID128_MAKE(a5,0a,d1,12,bf,60,45,77,a2,fb,74,1a,b1,95,5b,03)
+#define USEC_2000 ((usec_t) 946684800000000) /* 2000-01-01 00:00:00 UTC */
+
+int dhcp_validate_duid_len(uint16_t duid_type, size_t duid_len, bool strict) {
+ struct duid d;
+
+ assert_cc(sizeof(d.raw) >= MAX_DUID_LEN);
+ if (duid_len > MAX_DUID_LEN)
+ return -EINVAL;
+
+ if (!strict) {
+ /* Strict validation is not requested. We only ensure that the
+ * DUID is not too long. */
+ return 0;
+ }
+
+ switch (duid_type) {
+ case DUID_TYPE_LLT:
+ if (duid_len <= sizeof(d.llt))
+ return -EINVAL;
+ break;
+ case DUID_TYPE_EN:
+ if (duid_len != sizeof(d.en))
+ return -EINVAL;
+ break;
+ case DUID_TYPE_LL:
+ if (duid_len <= sizeof(d.ll))
+ return -EINVAL;
+ break;
+ case DUID_TYPE_UUID:
+ if (duid_len != sizeof(d.uuid))
+ return -EINVAL;
+ break;
+ default:
+ /* accept unknown type in order to be forward compatible */
+ break;
+ }
+ return 0;
+}
+
+int dhcp_identifier_set_duid_llt(struct duid *duid, usec_t t, const uint8_t *addr, size_t addr_len, uint16_t arp_type, size_t *len) {
+ uint16_t time_from_2000y;
+
+ assert(duid);
+ assert(len);
+ assert(addr);
+
+ if (arp_type == ARPHRD_ETHER)
+ assert_return(addr_len == ETH_ALEN, -EINVAL);
+ else if (arp_type == ARPHRD_INFINIBAND)
+ assert_return(addr_len == INFINIBAND_ALEN, -EINVAL);
+ else
+ return -EINVAL;
+
+ if (t < USEC_2000)
+ time_from_2000y = 0;
+ else
+ time_from_2000y = (uint16_t) (((t - USEC_2000) / USEC_PER_SEC) & 0xffffffff);
+
+ unaligned_write_be16(&duid->type, DUID_TYPE_LLT);
+ unaligned_write_be16(&duid->llt.htype, arp_type);
+ unaligned_write_be32(&duid->llt.time, time_from_2000y);
+ memcpy(duid->llt.haddr, addr, addr_len);
+
+ *len = sizeof(duid->type) + sizeof(duid->llt.htype) + sizeof(duid->llt.time) + addr_len;
+
+ return 0;
+}
+
+int dhcp_identifier_set_duid_ll(struct duid *duid, const uint8_t *addr, size_t addr_len, uint16_t arp_type, size_t *len) {
+ assert(duid);
+ assert(len);
+ assert(addr);
+
+ if (arp_type == ARPHRD_ETHER)
+ assert_return(addr_len == ETH_ALEN, -EINVAL);
+ else if (arp_type == ARPHRD_INFINIBAND)
+ assert_return(addr_len == INFINIBAND_ALEN, -EINVAL);
+ else
+ return -EINVAL;
+
+ unaligned_write_be16(&duid->type, DUID_TYPE_LL);
+ unaligned_write_be16(&duid->ll.htype, arp_type);
+ memcpy(duid->ll.haddr, addr, addr_len);
+
+ *len = sizeof(duid->type) + sizeof(duid->ll.htype) + addr_len;
+
+ return 0;
+}
+
+int dhcp_identifier_set_duid_en(struct duid *duid, size_t *len) {
+ sd_id128_t machine_id;
+ uint64_t hash;
+ int r;
+
+ assert(duid);
+ assert(len);
+
+ r = sd_id128_get_machine(&machine_id);
+ if (r < 0) {
+#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+ machine_id = SD_ID128_MAKE(01, 02, 03, 04, 05, 06, 07, 08, 09, 0a, 0b, 0c, 0d, 0e, 0f, 10);
+#else
+ return r;
+#endif
+ }
+
+ unaligned_write_be16(&duid->type, DUID_TYPE_EN);
+ unaligned_write_be32(&duid->en.pen, SYSTEMD_PEN);
+
+ *len = sizeof(duid->type) + sizeof(duid->en);
+
+ /* a bit of snake-oil perhaps, but no need to expose the machine-id
+ * directly; duid->en.id might not be aligned, so we need to copy */
+ hash = htole64(siphash24(&machine_id, sizeof(machine_id), HASH_KEY.bytes));
+ memcpy(duid->en.id, &hash, sizeof(duid->en.id));
+
+ return 0;
+}
+
+int dhcp_identifier_set_duid_uuid(struct duid *duid, size_t *len) {
+ sd_id128_t machine_id;
+ int r;
+
+ assert(duid);
+ assert(len);
+
+ r = sd_id128_get_machine_app_specific(APPLICATION_ID, &machine_id);
+ if (r < 0)
+ return r;
+
+ unaligned_write_be16(&duid->type, DUID_TYPE_UUID);
+ memcpy(&duid->raw.data, &machine_id, sizeof(machine_id));
+
+ *len = sizeof(duid->type) + sizeof(machine_id);
+
+ return 0;
+}
+
+int dhcp_identifier_set_iaid(
+ int ifindex,
+ const uint8_t *mac,
+ size_t mac_len,
+ bool legacy_unstable_byteorder,
+ void *_id) {
+ /* name is a pointer to memory in the sd_device struct, so must
+ * have the same scope */
+ _cleanup_(sd_device_unrefp) sd_device *device = NULL;
+ const char *name = NULL;
+ uint64_t id;
+ uint32_t id32;
+
+ if (detect_container() <= 0) {
+ /* not in a container, udev will be around */
+ char ifindex_str[1 + DECIMAL_STR_MAX(int)];
+ int r;
+
+ xsprintf(ifindex_str, "n%d", ifindex);
+ if (sd_device_new_from_device_id(&device, ifindex_str) >= 0) {
+ r = sd_device_get_is_initialized(device);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ /* not yet ready */
+ return -EBUSY;
+
+ name = net_get_name(device);
+ }
+ }
+
+ if (name)
+ id = siphash24(name, strlen(name), HASH_KEY.bytes);
+ else
+ /* fall back to MAC address if no predictable name available */
+ id = siphash24(mac, mac_len, HASH_KEY.bytes);
+
+ id32 = (id & 0xffffffff) ^ (id >> 32);
+
+ if (legacy_unstable_byteorder)
+ /* for historical reasons (a bug), the bits were swapped and thus
+ * the result was endianness dependent. Preserve that behavior. */
+ id32 = __bswap_32(id32);
+ else
+ /* the fixed behavior returns a stable byte order. Since LE is expected
+ * to be more common, swap the bytes on LE to give the same as legacy
+ * behavior. */
+ id32 = be32toh(id32);
+
+ unaligned_write_ne32(_id, id32);
+ return 0;
+}