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test-date: add missing header
[thirdparty/systemd.git] / src / libsystemd-network / dhcp-network.c
CommitLineData
db9ecf05 1/* SPDX-License-Identifier: LGPL-2.1-or-later */
8b4a9693 2/***
810adae9 3 Copyright © 2013 Intel Corporation. All rights reserved.
8b4a9693
PF
4***/
5
6#include <errno.h>
8b4a9693 7#include <net/ethernet.h>
3e7b9f76 8#include <net/if.h>
7429b07f 9#include <net/if_arp.h>
8b4a9693 10#include <stdio.h>
3ffd4af2 11#include <string.h>
bc29e507 12#include <linux/filter.h>
3ffd4af2
LP
13#include <linux/if_infiniband.h>
14#include <linux/if_packet.h>
8b4a9693 15
9bcbb614
YW
16#include "dhcp-network.h"
17#include "dhcp-protocol.h"
3ffd4af2 18#include "fd-util.h"
f11cba74 19#include "unaligned.h"
8b4a9693 20
073a1daa
YW
21static int _bind_raw_socket(
22 int ifindex,
23 union sockaddr_union *link,
24 uint32_t xid,
25 const struct hw_addr_data *hw_addr,
26 const struct hw_addr_data *bcast_addr,
27 uint16_t arp_type,
ea577968 28 uint16_t port,
29 bool so_priority_set,
30 int so_priority) {
073a1daa
YW
31
32 assert(ifindex > 0);
33 assert(link);
34 assert(hw_addr);
35 assert(bcast_addr);
36 assert(IN_SET(arp_type, ARPHRD_ETHER, ARPHRD_INFINIBAND));
37
38 switch (arp_type) {
39 case ARPHRD_ETHER:
40 assert(hw_addr->length == ETH_ALEN);
41 assert(bcast_addr->length == ETH_ALEN);
42 break;
43 case ARPHRD_INFINIBAND:
44 assert(hw_addr->length == 0);
45 assert(bcast_addr->length == INFINIBAND_ALEN);
46 break;
47 default:
48 assert_not_reached();
49 }
50
bc29e507 51 struct sock_filter filter[] = {
088b6ba2
LP
52 BPF_STMT(BPF_LD + BPF_W + BPF_LEN, 0), /* A <- packet length */
53 BPF_JUMP(BPF_JMP + BPF_JGE + BPF_K, sizeof(DHCPPacket), 1, 0), /* packet >= DHCPPacket ? */
54 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
55 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, ip.protocol)), /* A <- IP protocol */
56 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_UDP, 1, 0), /* IP protocol == UDP ? */
57 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
58 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, ip.frag_off)), /* A <- Flags */
59 BPF_STMT(BPF_ALU + BPF_AND + BPF_K, 0x20), /* A <- A & 0x20 (More Fragments bit) */
60 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 1, 0), /* A == 0 ? */
61 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
62 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(DHCPPacket, ip.frag_off)), /* A <- Flags + Fragment offset */
63 BPF_STMT(BPF_ALU + BPF_AND + BPF_K, 0x1fff), /* A <- A & 0x1fff (Fragment offset) */
64 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 1, 0), /* A == 0 ? */
65 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
66 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(DHCPPacket, udp.dest)), /* A <- UDP destination port */
9faed222 67 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, port, 1, 0), /* UDP destination port == DHCP client port ? */
088b6ba2
LP
68 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
69 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.op)), /* A <- DHCP op */
70 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, BOOTREPLY, 1, 0), /* op == BOOTREPLY ? */
71 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
72 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.htype)), /* A <- DHCP header type */
76253e73 73 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, arp_type, 1, 0), /* header type == arp_type ? */
088b6ba2 74 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
088b6ba2
LP
75 BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.xid)), /* A <- client identifier */
76 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, xid, 1, 0), /* client identifier == xid ? */
77 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
13f1fd03 78 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.hlen)), /* A <- MAC address length */
073a1daa 79 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, (uint8_t) hw_addr->length, 1, 0), /* address length == hw_addr->length ? */
13f1fd03
TH
80 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
81
82 /* We only support MAC address length to be either 0 or 6 (ETH_ALEN). Optionally
83 * compare chaddr for ETH_ALEN bytes. */
073a1daa
YW
84 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETH_ALEN, 0, 8), /* A (the MAC address length) == ETH_ALEN ? */
85 BPF_STMT(BPF_LDX + BPF_IMM, unaligned_read_be32(hw_addr->bytes)), /* X <- 4 bytes of client's MAC */
86 BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.chaddr)), /* A <- 4 bytes of MAC from dhcp.chaddr */
87 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_X, 0, 1, 0), /* A == X ? */
88 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
89 BPF_STMT(BPF_LDX + BPF_IMM, unaligned_read_be16(hw_addr->bytes + 4)), /* X <- remainder of client's MAC */
90 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(DHCPPacket, dhcp.chaddr) + 4), /* A <- remainder of MAC from dhcp.chaddr */
91 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_X, 0, 1, 0), /* A == X ? */
92 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
13f1fd03 93
088b6ba2
LP
94 BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.magic)), /* A <- DHCP magic cookie */
95 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DHCP_MAGIC_COOKIE, 1, 0), /* cookie == DHCP magic cookie ? */
96 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
ea51deb1 97 BPF_STMT(BPF_RET + BPF_K, UINT32_MAX), /* accept */
bc29e507
TG
98 };
99 struct sock_fprog fprog = {
088b6ba2
LP
100 .len = ELEMENTSOF(filter),
101 .filter = filter
bc29e507 102 };
5bb1d7fb 103 _cleanup_close_ int s = -EBADF;
6d5e65f6 104 int r;
8b4a9693 105
66a67eff 106 s = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
8b4a9693
PF
107 if (s < 0)
108 return -errno;
109
2ff48e98 110 r = setsockopt_int(s, SOL_PACKET, PACKET_AUXDATA, true);
c3d2994b 111 if (r < 0)
2ff48e98 112 return r;
c3d2994b
TG
113
114 r = setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &fprog, sizeof(fprog));
115 if (r < 0)
116 return -errno;
117
905d0ea7
YW
118 r = setsockopt_int(s, SOL_SOCKET, SO_TIMESTAMP, true);
119 if (r < 0)
120 return r;
121
ea577968 122 if (so_priority_set) {
123 r = setsockopt_int(s, SOL_SOCKET, SO_PRIORITY, so_priority);
124 if (r < 0)
125 return r;
126 }
127
b1f24b75
BG
128 link->ll = (struct sockaddr_ll) {
129 .sll_family = AF_PACKET,
130 .sll_protocol = htobe16(ETH_P_IP),
131 .sll_ifindex = ifindex,
132 .sll_hatype = htobe16(arp_type),
073a1daa 133 .sll_halen = bcast_addr->length,
b1f24b75 134 };
073a1daa
YW
135 /* We may overflow link->ll. link->ll_buffer ensures we have enough space. */
136 memcpy(link->ll.sll_addr, bcast_addr->bytes, bcast_addr->length);
8b4a9693 137
b1f24b75 138 r = bind(s, &link->sa, SOCKADDR_LL_LEN(link->ll));
c3d2994b 139 if (r < 0)
bc29e507 140 return -errno;
bc29e507 141
c10d6bdb 142 return TAKE_FD(s);
8c00042c
PF
143}
144
155943b2
YW
145int dhcp_network_bind_raw_socket(
146 int ifindex,
147 union sockaddr_union *link,
148 uint32_t xid,
073a1daa
YW
149 const struct hw_addr_data *hw_addr,
150 const struct hw_addr_data *bcast_addr,
155943b2 151 uint16_t arp_type,
ea577968 152 uint16_t port,
153 bool so_priority_set,
154 int so_priority) {
155943b2 155
073a1daa
YW
156 static struct hw_addr_data default_eth_bcast = {
157 .length = ETH_ALEN,
158 .ether = {{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }},
159 }, default_ib_bcast = {
160 .length = INFINIBAND_ALEN,
161 .infiniband = {
162 0x00, 0xff, 0xff, 0xff, 0xff, 0x12, 0x40, 0x1b,
163 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
164 0xff, 0xff, 0xff, 0xff
165 },
14b66dbc 166 };
76253e73 167
073a1daa
YW
168 assert(ifindex > 0);
169 assert(link);
170 assert(hw_addr);
171
172 switch (arp_type) {
173 case ARPHRD_ETHER:
174 return _bind_raw_socket(ifindex, link, xid,
175 hw_addr,
176 (bcast_addr && !hw_addr_is_null(bcast_addr)) ? bcast_addr : &default_eth_bcast,
ea577968 177 arp_type, port, so_priority_set, so_priority);
073a1daa
YW
178
179 case ARPHRD_INFINIBAND:
180 return _bind_raw_socket(ifindex, link, xid,
181 &HW_ADDR_NULL,
182 (bcast_addr && !hw_addr_is_null(bcast_addr)) ? bcast_addr : &default_ib_bcast,
ea577968 183 arp_type, port, so_priority_set, so_priority);
073a1daa
YW
184 default:
185 return -EINVAL;
14b66dbc 186 }
76253e73
DW
187}
188
afe42aef 189int dhcp_network_bind_udp_socket(int ifindex, be32_t address, uint16_t port, int ip_service_type) {
234fc2df
PF
190 union sockaddr_union src = {
191 .in.sin_family = AF_INET,
080ab276
TG
192 .in.sin_port = htobe16(port),
193 .in.sin_addr.s_addr = address,
234fc2df 194 };
5bb1d7fb 195 _cleanup_close_ int s = -EBADF;
9e5b6496 196 int r;
234fc2df
PF
197
198 s = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
199 if (s < 0)
200 return -errno;
201
afe42aef
SC
202 if (ip_service_type >= 0)
203 r = setsockopt_int(s, IPPROTO_IP, IP_TOS, ip_service_type);
204 else
205 r = setsockopt_int(s, IPPROTO_IP, IP_TOS, IPTOS_CLASS_CS6);
c3d2994b 206 if (r < 0)
9e5b6496 207 return r;
b44cd882 208
2ff48e98 209 r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
076adf01 210 if (r < 0)
2ff48e98 211 return r;
fef0e0f3 212
905d0ea7
YW
213 r = setsockopt_int(s, SOL_SOCKET, SO_TIMESTAMP, true);
214 if (r < 0)
215 return r;
216
3e7b9f76 217 if (ifindex > 0) {
953a02d1 218 r = socket_bind_to_ifindex(s, ifindex);
3e7b9f76 219 if (r < 0)
953a02d1 220 return r;
3e7b9f76
MK
221 }
222
21b6b87e 223 if (port == DHCP_PORT_SERVER) {
2ff48e98 224 r = setsockopt_int(s, SOL_SOCKET, SO_BROADCAST, true);
d6bd972d 225 if (r < 0)
2ff48e98 226 return r;
21b6b87e
YA
227 if (address == INADDR_ANY) {
228 /* IP_PKTINFO filter should not be applied when packets are
229 allowed to enter/leave through the interface other than
230 DHCP server sits on(BindToInterface option). */
231 r = setsockopt_int(s, IPPROTO_IP, IP_PKTINFO, true);
232 if (r < 0)
233 return r;
234 }
076adf01 235 } else {
2ff48e98 236 r = setsockopt_int(s, IPPROTO_IP, IP_FREEBIND, true);
076adf01 237 if (r < 0)
2ff48e98 238 return r;
fef0e0f3 239 }
85923f79 240
d70c7813 241 if (bind(s, &src.sa, sizeof(src.in)) < 0)
234fc2df 242 return -errno;
234fc2df 243
c10d6bdb 244 return TAKE_FD(s);
234fc2df
PF
245}
246
155943b2
YW
247int dhcp_network_send_raw_socket(
248 int s,
249 const union sockaddr_union *link,
250 const void *packet,
251 size_t len) {
c3d2994b 252
b8319d74
YW
253 /* Do not add assert(s >= 0) here, as this is called in fuzz-dhcp-server, and in that case this
254 * function should fail with negative errno. */
255
23f30ed3
TG
256 assert(link);
257 assert(packet);
b8319d74 258 assert(len > 0);
23f30ed3 259
d70c7813 260 if (sendto(s, packet, len, 0, &link->sa, SOCKADDR_LL_LEN(link->ll)) < 0)
1c8035a8 261 return -errno;
8b4a9693 262
1c8035a8 263 return 0;
8b4a9693 264}
234fc2df 265
155943b2
YW
266int dhcp_network_send_udp_socket(
267 int s,
268 be32_t address,
269 uint16_t port,
270 const void *packet,
271 size_t len) {
272
234fc2df
PF
273 union sockaddr_union dest = {
274 .in.sin_family = AF_INET,
080ab276
TG
275 .in.sin_port = htobe16(port),
276 .in.sin_addr.s_addr = address,
234fc2df 277 };
c3d2994b
TG
278
279 assert(s >= 0);
280 assert(packet);
b8319d74 281 assert(len > 0);
234fc2df 282
d70c7813 283 if (sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in)) < 0)
234fc2df
PF
284 return -errno;
285
286 return 0;
287}