/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include "sd-device.h" #include "sd-id128.h" #include "dhcp-identifier.h" #include "netif-util.h" #include "siphash24.h" #include "sparse-endian.h" #include "stat-util.h" #include "string-table.h" #include "udev-util.h" #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 */ static const char * const duid_type_table[_DUID_TYPE_MAX] = { [DUID_TYPE_LLT] = "DUID-LLT", [DUID_TYPE_EN] = "DUID-EN/Vendor", [DUID_TYPE_LL] = "DUID-LL", [DUID_TYPE_UUID] = "UUID", }; DEFINE_STRING_TABLE_LOOKUP_TO_STRING(duid_type, DUIDType); int dhcp_validate_duid_len(DUIDType 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; } static int dhcp_identifier_set_duid_llt(const uint8_t *addr, size_t addr_len, uint16_t arp_type, usec_t t, struct duid *ret_duid, size_t *ret_len) { uint16_t time_from_2000y; assert(addr); assert(ret_duid); assert(ret_len); if (addr_len == 0) return -EOPNOTSUPP; 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 -EOPNOTSUPP; if (t < USEC_2000) time_from_2000y = 0; else time_from_2000y = (uint16_t) (((t - USEC_2000) / USEC_PER_SEC) & 0xffffffff); unaligned_write_be16(&ret_duid->type, DUID_TYPE_LLT); unaligned_write_be16(&ret_duid->llt.htype, arp_type); unaligned_write_be32(&ret_duid->llt.time, time_from_2000y); memcpy(ret_duid->llt.haddr, addr, addr_len); *ret_len = offsetof(struct duid, llt.haddr) + addr_len; return 0; } static int dhcp_identifier_set_duid_ll(const uint8_t *addr, size_t addr_len, uint16_t arp_type, struct duid *ret_duid, size_t *ret_len) { assert(addr); assert(ret_duid); assert(ret_len); if (addr_len == 0) return -EOPNOTSUPP; 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 -EOPNOTSUPP; unaligned_write_be16(&ret_duid->type, DUID_TYPE_LL); unaligned_write_be16(&ret_duid->ll.htype, arp_type); memcpy(ret_duid->ll.haddr, addr, addr_len); *ret_len = offsetof(struct duid, ll.haddr) + addr_len; return 0; } int dhcp_identifier_set_duid_en(bool test_mode, struct duid *ret_duid, size_t *ret_len) { sd_id128_t machine_id; uint64_t hash; int r; assert(ret_duid); assert(ret_len); if (!test_mode) { r = sd_id128_get_machine(&machine_id); if (r < 0) return r; } else /* For tests, especially for fuzzers, reproducibility is important. * Hence, use a static and constant machine ID. * See 9216fddc5a8ac2742e6cfa7660f95c20ca4f2193. */ machine_id = SD_ID128_MAKE(01, 02, 03, 04, 05, 06, 07, 08, 09, 0a, 0b, 0c, 0d, 0e, 0f, 10); unaligned_write_be16(&ret_duid->type, DUID_TYPE_EN); unaligned_write_be32(&ret_duid->en.pen, SYSTEMD_PEN); /* 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(ret_duid->en.id, &hash, sizeof(ret_duid->en.id)); *ret_len = offsetof(struct duid, en.id) + sizeof(ret_duid->en.id); if (test_mode) assert_se(memcmp(ret_duid, (const uint8_t[]) { 0x00, 0x02, 0x00, 0x00, 0xab, 0x11, 0x61, 0x77, 0x40, 0xde, 0x13, 0x42, 0xc3, 0xa2 }, *ret_len) == 0); return 0; } static int dhcp_identifier_set_duid_uuid(struct duid *ret_duid, size_t *ret_len) { sd_id128_t machine_id; int r; assert(ret_duid); assert(ret_len); r = sd_id128_get_machine_app_specific(APPLICATION_ID, &machine_id); if (r < 0) return r; unaligned_write_be16(&ret_duid->type, DUID_TYPE_UUID); memcpy(&ret_duid->uuid.uuid, &machine_id, sizeof(machine_id)); *ret_len = offsetof(struct duid, uuid.uuid) + sizeof(machine_id); return 0; } int dhcp_identifier_set_duid( DUIDType duid_type, const uint8_t *addr, size_t addr_len, uint16_t arp_type, usec_t llt_time, bool test_mode, struct duid *ret_duid, size_t *ret_len) { switch (duid_type) { case DUID_TYPE_LLT: return dhcp_identifier_set_duid_llt(addr, addr_len, arp_type, llt_time, ret_duid, ret_len); case DUID_TYPE_EN: return dhcp_identifier_set_duid_en(test_mode, ret_duid, ret_len); case DUID_TYPE_LL: return dhcp_identifier_set_duid_ll(addr, addr_len, arp_type, ret_duid, ret_len); case DUID_TYPE_UUID: return dhcp_identifier_set_duid_uuid(ret_duid, ret_len); default: return -EINVAL; } } int dhcp_identifier_set_iaid( int ifindex, const uint8_t *mac, size_t mac_len, bool legacy_unstable_byteorder, bool use_mac, void *ret) { /* 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; uint32_t id32; uint64_t id; int r; if (path_is_read_only_fs("/sys") <= 0 && !use_mac) { /* udev should be around */ r = sd_device_new_from_ifindex(&device, ifindex); if (r < 0) return r; r = sd_device_get_is_initialized(device); if (r < 0) return r; if (r == 0) /* not yet ready */ return -EBUSY; r = device_is_renaming(device); if (r < 0) return r; if (r > 0) /* device is under renaming */ return -EBUSY; name = net_get_persistent_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(ret, id32); return 0; }