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git.ipfire.org Git - thirdparty/systemd.git/blob - src/libsystemd-network/dhcp-identifier.c
1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 #include <linux/if_infiniband.h>
8 #include "dhcp-identifier.h"
9 #include "dhcp6-protocol.h"
10 #include "network-internal.h"
11 #include "siphash24.h"
12 #include "sparse-endian.h"
13 #include "udev-util.h"
16 #define SYSTEMD_PEN 43793
17 #define HASH_KEY SD_ID128_MAKE(80,11,8c,c2,fe,4a,03,ee,3e,d6,0c,6f,36,39,14,09)
18 #define APPLICATION_ID SD_ID128_MAKE(a5,0a,d1,12,bf,60,45,77,a2,fb,74,1a,b1,95,5b,03)
19 #define USEC_2000 ((usec_t) 946684800000000) /* 2000-01-01 00:00:00 UTC */
21 int dhcp_validate_duid_len(uint16_t duid_type
, size_t duid_len
) {
24 assert_cc(sizeof(d
.raw
) >= MAX_DUID_LEN
);
25 if (duid_len
> MAX_DUID_LEN
)
30 if (duid_len
<= sizeof(d
.llt
))
34 if (duid_len
!= sizeof(d
.en
))
38 if (duid_len
<= sizeof(d
.ll
))
42 if (duid_len
!= sizeof(d
.uuid
))
46 /* accept unknown type in order to be forward compatible */
52 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
) {
53 uint16_t time_from_2000y
;
59 if (arp_type
== ARPHRD_ETHER
)
60 assert_return(addr_len
== ETH_ALEN
, -EINVAL
);
61 else if (arp_type
== ARPHRD_INFINIBAND
)
62 assert_return(addr_len
== INFINIBAND_ALEN
, -EINVAL
);
69 time_from_2000y
= (uint16_t) (((t
- USEC_2000
) / USEC_PER_SEC
) & 0xffffffff);
71 unaligned_write_be16(&duid
->type
, DUID_TYPE_LLT
);
72 unaligned_write_be16(&duid
->llt
.htype
, arp_type
);
73 unaligned_write_be32(&duid
->llt
.time
, time_from_2000y
);
74 memcpy(duid
->llt
.haddr
, addr
, addr_len
);
76 *len
= sizeof(duid
->type
) + sizeof(duid
->llt
.htype
) + sizeof(duid
->llt
.time
) + addr_len
;
81 int dhcp_identifier_set_duid_ll(struct duid
*duid
, const uint8_t *addr
, size_t addr_len
, uint16_t arp_type
, size_t *len
) {
86 if (arp_type
== ARPHRD_ETHER
)
87 assert_return(addr_len
== ETH_ALEN
, -EINVAL
);
88 else if (arp_type
== ARPHRD_INFINIBAND
)
89 assert_return(addr_len
== INFINIBAND_ALEN
, -EINVAL
);
93 unaligned_write_be16(&duid
->type
, DUID_TYPE_LL
);
94 unaligned_write_be16(&duid
->ll
.htype
, arp_type
);
95 memcpy(duid
->ll
.haddr
, addr
, addr_len
);
97 *len
= sizeof(duid
->type
) + sizeof(duid
->ll
.htype
) + addr_len
;
102 int dhcp_identifier_set_duid_en(struct duid
*duid
, size_t *len
) {
103 sd_id128_t machine_id
;
110 r
= sd_id128_get_machine(&machine_id
);
114 unaligned_write_be16(&duid
->type
, DUID_TYPE_EN
);
115 unaligned_write_be32(&duid
->en
.pen
, SYSTEMD_PEN
);
117 *len
= sizeof(duid
->type
) + sizeof(duid
->en
);
119 /* a bit of snake-oil perhaps, but no need to expose the machine-id
120 * directly; duid->en.id might not be aligned, so we need to copy */
121 hash
= htole64(siphash24(&machine_id
, sizeof(machine_id
), HASH_KEY
.bytes
));
122 memcpy(duid
->en
.id
, &hash
, sizeof(duid
->en
.id
));
127 int dhcp_identifier_set_duid_uuid(struct duid
*duid
, size_t *len
) {
128 sd_id128_t machine_id
;
134 r
= sd_id128_get_machine_app_specific(APPLICATION_ID
, &machine_id
);
138 unaligned_write_be16(&duid
->type
, DUID_TYPE_UUID
);
139 memcpy(&duid
->raw
.data
, &machine_id
, sizeof(machine_id
));
141 *len
= sizeof(duid
->type
) + sizeof(machine_id
);
146 int dhcp_identifier_set_iaid(int ifindex
, uint8_t *mac
, size_t mac_len
, void *_id
) {
147 /* name is a pointer to memory in the udev_device struct, so must
148 have the same scope */
149 _cleanup_(udev_device_unrefp
) struct udev_device
*device
= NULL
;
150 const char *name
= NULL
;
153 if (detect_container() <= 0) {
154 /* not in a container, udev will be around */
155 _cleanup_(udev_unrefp
) struct udev
*udev
;
156 char ifindex_str
[2 + DECIMAL_STR_MAX(int)];
162 sprintf(ifindex_str
, "n%d", ifindex
);
163 device
= udev_device_new_from_device_id(udev
, ifindex_str
);
165 if (udev_device_get_is_initialized(device
) <= 0)
169 name
= net_get_name(device
);
174 id
= siphash24(name
, strlen(name
), HASH_KEY
.bytes
);
176 /* fall back to MAC address if no predictable name available */
177 id
= siphash24(mac
, mac_len
, HASH_KEY
.bytes
);
181 /* fold into 32 bits */
182 unaligned_write_be32(_id
, (id
& 0xffffffff) ^ (id
>> 32));