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db9ecf05 | 1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
b44cd882 | 2 | /*** |
810adae9 | 3 | Copyright © 2013 Intel Corporation. All rights reserved. |
b44cd882 TG |
4 | ***/ |
5 | ||
ddb82ec2 | 6 | #include <net/if_arp.h> |
ff734080 TG |
7 | #include <sys/ioctl.h> |
8 | ||
b44cd882 | 9 | #include "sd-dhcp-server.h" |
6e86b24d | 10 | #include "sd-id128.h" |
07630cea | 11 | |
b5efdb8a | 12 | #include "alloc-util.h" |
ff734080 | 13 | #include "dhcp-internal.h" |
07630cea | 14 | #include "dhcp-server-internal.h" |
3ffd4af2 | 15 | #include "fd-util.h" |
07630cea | 16 | #include "in-addr-util.h" |
cb310866 | 17 | #include "io-util.h" |
61a9fa8f | 18 | #include "network-common.h" |
ebffea2a | 19 | #include "ordered-set.h" |
07630cea LP |
20 | #include "siphash24.h" |
21 | #include "string-util.h" | |
9ae84244 | 22 | #include "unaligned.h" |
b44cd882 | 23 | |
586ac6f7 LP |
24 | #define DHCP_DEFAULT_LEASE_TIME_USEC USEC_PER_HOUR |
25 | #define DHCP_MAX_LEASE_TIME_USEC (USEC_PER_HOUR*12) | |
4dc35568 | 26 | |
6121fc30 | 27 | static DHCPLease *dhcp_lease_free(DHCPLease *lease) { |
45a9eac9 | 28 | if (!lease) |
6121fc30 | 29 | return NULL; |
45a9eac9 RM |
30 | |
31 | free(lease->client_id.data); | |
6121fc30 | 32 | return mfree(lease); |
45a9eac9 RM |
33 | } |
34 | ||
99634696 TG |
35 | /* configures the server's address and subnet, and optionally the pool's size and offset into the subnet |
36 | * the whole pool must fit into the subnet, and may not contain the first (any) nor last (broadcast) address | |
37 | * moreover, the server's own address may be in the pool, and is in that case reserved in order not to | |
38 | * accidentally hand it out */ | |
90810f7a LP |
39 | int sd_dhcp_server_configure_pool( |
40 | sd_dhcp_server *server, | |
41 | const struct in_addr *address, | |
42 | unsigned char prefixlen, | |
43 | uint32_t offset, | |
44 | uint32_t size) { | |
45 | ||
99634696 TG |
46 | struct in_addr netmask_addr; |
47 | be32_t netmask; | |
48 | uint32_t server_off, broadcast_off, size_max; | |
49 | ||
2dead812 TG |
50 | assert_return(server, -EINVAL); |
51 | assert_return(address, -EINVAL); | |
99634696 TG |
52 | assert_return(address->s_addr != INADDR_ANY, -EINVAL); |
53 | assert_return(prefixlen <= 32, -ERANGE); | |
99634696 | 54 | |
5a941f5f | 55 | assert_se(in4_addr_prefixlen_to_netmask(&netmask_addr, prefixlen)); |
99634696 TG |
56 | netmask = netmask_addr.s_addr; |
57 | ||
58 | server_off = be32toh(address->s_addr & ~netmask); | |
59 | broadcast_off = be32toh(~netmask); | |
60 | ||
61 | /* the server address cannot be the subnet address */ | |
62 | assert_return(server_off != 0, -ERANGE); | |
63 | ||
64 | /* nor the broadcast address */ | |
65 | assert_return(server_off != broadcast_off, -ERANGE); | |
66 | ||
67 | /* 0 offset means we should set a default, we skip the first (subnet) address | |
68 | and take the next one */ | |
69 | if (offset == 0) | |
70 | offset = 1; | |
71 | ||
72 | size_max = (broadcast_off + 1) /* the number of addresses in the subnet */ | |
73 | - offset /* exclude the addresses before the offset */ | |
74 | - 1; /* exclude the last (broadcast) address */ | |
75 | ||
76 | /* The pool must contain at least one address */ | |
77 | assert_return(size_max >= 1, -ERANGE); | |
78 | ||
79 | if (size != 0) | |
80 | assert_return(size <= size_max, -ERANGE); | |
81 | else | |
82 | size = size_max; | |
87322b3a | 83 | |
45a9eac9 | 84 | if (server->address != address->s_addr || server->netmask != netmask || server->pool_size != size || server->pool_offset != offset) { |
45a9eac9 RM |
85 | |
86 | free(server->bound_leases); | |
87 | server->bound_leases = new0(DHCPLease*, size); | |
88 | if (!server->bound_leases) | |
89 | return -ENOMEM; | |
2dead812 | 90 | |
45a9eac9 RM |
91 | server->pool_offset = offset; |
92 | server->pool_size = size; | |
2dead812 | 93 | |
45a9eac9 RM |
94 | server->address = address->s_addr; |
95 | server->netmask = netmask; | |
96 | server->subnet = address->s_addr & netmask; | |
99634696 | 97 | |
45a9eac9 RM |
98 | if (server_off >= offset && server_off - offset < size) |
99 | server->bound_leases[server_off - offset] = &server->invalid_lease; | |
100 | ||
101 | /* Drop any leases associated with the old address range */ | |
6121fc30 | 102 | hashmap_clear(server->leases_by_client_id); |
36d35f22 MAL |
103 | |
104 | if (server->callback) | |
105 | server->callback(server, SD_DHCP_SERVER_EVENT_LEASE_CHANGED, server->callback_userdata); | |
45a9eac9 | 106 | } |
20af7091 TG |
107 | |
108 | return 0; | |
109 | } | |
110 | ||
04c01369 | 111 | int sd_dhcp_server_is_running(sd_dhcp_server *server) { |
75677581 | 112 | assert_return(server, false); |
7c16313f TG |
113 | |
114 | return !!server->receive_message; | |
115 | } | |
116 | ||
c95df587 YA |
117 | int sd_dhcp_server_is_in_relay_mode(sd_dhcp_server *server) { |
118 | assert_return(server, -EINVAL); | |
119 | ||
120 | return in4_addr_is_set(&server->relay_target); | |
121 | } | |
122 | ||
7a08d314 | 123 | void client_id_hash_func(const DHCPClientId *id, struct siphash *state) { |
87322b3a TG |
124 | assert(id); |
125 | assert(id->length); | |
126 | assert(id->data); | |
127 | ||
1e2527a6 | 128 | siphash24_compress(&id->length, sizeof(id->length), state); |
b826ab58 | 129 | siphash24_compress(id->data, id->length, state); |
87322b3a TG |
130 | } |
131 | ||
7a08d314 | 132 | int client_id_compare_func(const DHCPClientId *a, const DHCPClientId *b) { |
a0edd02e | 133 | int r; |
87322b3a | 134 | |
87322b3a TG |
135 | assert(!a->length || a->data); |
136 | assert(!b->length || b->data); | |
137 | ||
a0edd02e FB |
138 | r = CMP(a->length, b->length); |
139 | if (r != 0) | |
140 | return r; | |
87322b3a TG |
141 | |
142 | return memcmp(a->data, b->data, a->length); | |
143 | } | |
144 | ||
6121fc30 YW |
145 | DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(dhcp_lease_hash_ops, DHCPClientId, client_id_hash_func, client_id_compare_func, |
146 | DHCPLease, dhcp_lease_free); | |
d5099efc | 147 | |
8301aa0b | 148 | static sd_dhcp_server *dhcp_server_free(sd_dhcp_server *server) { |
8301aa0b | 149 | assert(server); |
ff734080 | 150 | |
3bdace9b | 151 | log_dhcp_server(server, "UNREF"); |
87322b3a | 152 | |
3bdace9b | 153 | sd_dhcp_server_stop(server); |
87322b3a | 154 | |
3bdace9b LP |
155 | sd_event_unref(server->event); |
156 | ||
8eb9058d | 157 | free(server->timezone); |
ddb82ec2 | 158 | |
2324fd3a | 159 | for (sd_dhcp_lease_server_type_t i = 0; i < _SD_DHCP_LEASE_SERVER_TYPE_MAX; i++) |
ddb82ec2 | 160 | free(server->servers[i].addr); |
8eb9058d | 161 | |
3bdace9b LP |
162 | hashmap_free(server->leases_by_client_id); |
163 | ||
ebffea2a SS |
164 | ordered_set_free(server->extra_options); |
165 | ordered_set_free(server->vendor_options); | |
564ca984 | 166 | |
11c38d3e YA |
167 | free(server->agent_circuit_id); |
168 | free(server->agent_remote_id); | |
169 | ||
3bdace9b | 170 | free(server->bound_leases); |
61a9fa8f YW |
171 | |
172 | free(server->ifname); | |
6b430fdb | 173 | return mfree(server); |
b44cd882 TG |
174 | } |
175 | ||
8301aa0b YW |
176 | DEFINE_TRIVIAL_REF_UNREF_FUNC(sd_dhcp_server, sd_dhcp_server, dhcp_server_free); |
177 | ||
3a864fe4 | 178 | int sd_dhcp_server_new(sd_dhcp_server **ret, int ifindex) { |
4afd3348 | 179 | _cleanup_(sd_dhcp_server_unrefp) sd_dhcp_server *server = NULL; |
b44cd882 TG |
180 | |
181 | assert_return(ret, -EINVAL); | |
3a864fe4 | 182 | assert_return(ifindex > 0, -EINVAL); |
b44cd882 | 183 | |
61a9fa8f | 184 | server = new(sd_dhcp_server, 1); |
b44cd882 TG |
185 | if (!server) |
186 | return -ENOMEM; | |
187 | ||
61a9fa8f YW |
188 | *server = (sd_dhcp_server) { |
189 | .n_ref = 1, | |
190 | .fd_raw = -1, | |
191 | .fd = -1, | |
21b6b87e | 192 | .fd_broadcast = -1, |
61a9fa8f YW |
193 | .address = htobe32(INADDR_ANY), |
194 | .netmask = htobe32(INADDR_ANY), | |
195 | .ifindex = ifindex, | |
21b6b87e | 196 | .bind_to_interface = true, |
61a9fa8f YW |
197 | .default_lease_time = DIV_ROUND_UP(DHCP_DEFAULT_LEASE_TIME_USEC, USEC_PER_SEC), |
198 | .max_lease_time = DIV_ROUND_UP(DHCP_MAX_LEASE_TIME_USEC, USEC_PER_SEC), | |
199 | }; | |
357e1b17 | 200 | |
6121fc30 | 201 | server->leases_by_client_id = hashmap_new(&dhcp_lease_hash_ops); |
357e1b17 LP |
202 | if (!server->leases_by_client_id) |
203 | return -ENOMEM; | |
204 | ||
1cc6c93a | 205 | *ret = TAKE_PTR(server); |
b44cd882 TG |
206 | |
207 | return 0; | |
208 | } | |
209 | ||
61a9fa8f YW |
210 | int sd_dhcp_server_set_ifname(sd_dhcp_server *server, const char *ifname) { |
211 | assert_return(server, -EINVAL); | |
212 | assert_return(ifname, -EINVAL); | |
213 | ||
214 | if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE)) | |
215 | return -EINVAL; | |
216 | ||
217 | return free_and_strdup(&server->ifname, ifname); | |
218 | } | |
219 | ||
220 | const char *sd_dhcp_server_get_ifname(sd_dhcp_server *server) { | |
221 | if (!server) | |
222 | return NULL; | |
223 | ||
224 | return get_ifname(server->ifindex, &server->ifname); | |
225 | } | |
226 | ||
32d20645 | 227 | int sd_dhcp_server_attach_event(sd_dhcp_server *server, sd_event *event, int64_t priority) { |
b44cd882 TG |
228 | int r; |
229 | ||
230 | assert_return(server, -EINVAL); | |
231 | assert_return(!server->event, -EBUSY); | |
232 | ||
233 | if (event) | |
234 | server->event = sd_event_ref(event); | |
235 | else { | |
236 | r = sd_event_default(&server->event); | |
237 | if (r < 0) | |
238 | return r; | |
239 | } | |
240 | ||
241 | server->event_priority = priority; | |
242 | ||
243 | return 0; | |
244 | } | |
245 | ||
246 | int sd_dhcp_server_detach_event(sd_dhcp_server *server) { | |
247 | assert_return(server, -EINVAL); | |
248 | ||
249 | server->event = sd_event_unref(server->event); | |
250 | ||
251 | return 0; | |
252 | } | |
253 | ||
254 | sd_event *sd_dhcp_server_get_event(sd_dhcp_server *server) { | |
255 | assert_return(server, NULL); | |
256 | ||
257 | return server->event; | |
258 | } | |
ff734080 TG |
259 | |
260 | int sd_dhcp_server_stop(sd_dhcp_server *server) { | |
c8bae363 YW |
261 | if (!server) |
262 | return 0; | |
ff734080 | 263 | |
21b6b87e YA |
264 | server->receive_message = sd_event_source_unref(server->receive_message); |
265 | server->receive_broadcast = sd_event_source_unref(server->receive_broadcast); | |
ff734080 | 266 | |
8de4a226 | 267 | server->fd_raw = safe_close(server->fd_raw); |
ff734080 | 268 | server->fd = safe_close(server->fd); |
21b6b87e | 269 | server->fd_broadcast = safe_close(server->fd_broadcast); |
ff734080 TG |
270 | |
271 | log_dhcp_server(server, "STOPPED"); | |
272 | ||
273 | return 0; | |
274 | } | |
275 | ||
a6f1e036 TG |
276 | static int dhcp_server_send_unicast_raw(sd_dhcp_server *server, |
277 | DHCPPacket *packet, size_t len) { | |
969b009d TG |
278 | union sockaddr_union link = { |
279 | .ll.sll_family = AF_PACKET, | |
8e38570e | 280 | .ll.sll_protocol = htobe16(ETH_P_IP), |
b3ec603c | 281 | .ll.sll_ifindex = server->ifindex, |
969b009d TG |
282 | .ll.sll_halen = ETH_ALEN, |
283 | }; | |
969b009d TG |
284 | |
285 | assert(server); | |
b3ec603c | 286 | assert(server->ifindex > 0); |
969b009d TG |
287 | assert(server->address); |
288 | assert(packet); | |
289 | assert(len > sizeof(DHCPPacket)); | |
290 | ||
291 | memcpy(&link.ll.sll_addr, &packet->dhcp.chaddr, ETH_ALEN); | |
292 | ||
293 | dhcp_packet_append_ip_headers(packet, server->address, DHCP_PORT_SERVER, | |
a6f1e036 | 294 | packet->dhcp.yiaddr, |
afe42aef | 295 | DHCP_PORT_CLIENT, len, -1); |
969b009d | 296 | |
b3ec603c | 297 | return dhcp_network_send_raw_socket(server->fd_raw, &link, packet, len); |
969b009d TG |
298 | } |
299 | ||
300 | static int dhcp_server_send_udp(sd_dhcp_server *server, be32_t destination, | |
8eb7b6a5 | 301 | uint16_t destination_port, |
969b009d TG |
302 | DHCPMessage *message, size_t len) { |
303 | union sockaddr_union dest = { | |
304 | .in.sin_family = AF_INET, | |
8eb7b6a5 | 305 | .in.sin_port = htobe16(destination_port), |
969b009d TG |
306 | .in.sin_addr.s_addr = destination, |
307 | }; | |
308 | struct iovec iov = { | |
309 | .iov_base = message, | |
310 | .iov_len = len, | |
311 | }; | |
fb29cdbe | 312 | CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct in_pktinfo))) control = {}; |
969b009d TG |
313 | struct msghdr msg = { |
314 | .msg_name = &dest, | |
315 | .msg_namelen = sizeof(dest.in), | |
316 | .msg_iov = &iov, | |
317 | .msg_iovlen = 1, | |
969b009d TG |
318 | }; |
319 | struct cmsghdr *cmsg; | |
320 | struct in_pktinfo *pktinfo; | |
969b009d TG |
321 | |
322 | assert(server); | |
4c9cb12c | 323 | assert(server->fd >= 0); |
969b009d TG |
324 | assert(message); |
325 | assert(len > sizeof(DHCPMessage)); | |
326 | ||
21b6b87e YA |
327 | if (server->bind_to_interface) { |
328 | msg.msg_control = &control; | |
329 | msg.msg_controllen = sizeof(control); | |
969b009d | 330 | |
21b6b87e YA |
331 | cmsg = CMSG_FIRSTHDR(&msg); |
332 | assert(cmsg); | |
969b009d | 333 | |
21b6b87e YA |
334 | cmsg->cmsg_level = IPPROTO_IP; |
335 | cmsg->cmsg_type = IP_PKTINFO; | |
336 | cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo)); | |
969b009d | 337 | |
21b6b87e YA |
338 | /* we attach source interface and address info to the message |
339 | rather than binding the socket. This will be mostly useful | |
340 | when we gain support for arbitrary number of server addresses | |
341 | */ | |
342 | pktinfo = (struct in_pktinfo*) CMSG_DATA(cmsg); | |
343 | assert(pktinfo); | |
344 | ||
345 | pktinfo->ipi_ifindex = server->ifindex; | |
346 | pktinfo->ipi_spec_dst.s_addr = server->address; | |
347 | } | |
969b009d | 348 | |
0f01c1f9 | 349 | if (sendmsg(server->fd, &msg, 0) < 0) |
969b009d TG |
350 | return -errno; |
351 | ||
352 | return 0; | |
353 | } | |
354 | ||
c95df587 YA |
355 | static bool requested_broadcast(DHCPMessage *message) { |
356 | assert(message); | |
357 | return message->flags & htobe16(0x8000); | |
358 | } | |
969b009d | 359 | |
c95df587 YA |
360 | static int dhcp_server_send(sd_dhcp_server *server, be32_t destination, uint16_t destination_port, |
361 | DHCPPacket *packet, size_t optoffset, bool l2_broadcast) { | |
362 | if (destination != INADDR_ANY) | |
363 | return dhcp_server_send_udp(server, destination, | |
364 | destination_port, &packet->dhcp, | |
365 | sizeof(DHCPMessage) + optoffset); | |
366 | else if (l2_broadcast) | |
367 | return dhcp_server_send_udp(server, INADDR_BROADCAST, | |
368 | destination_port, &packet->dhcp, | |
369 | sizeof(DHCPMessage) + optoffset); | |
370 | else | |
371 | /* we cannot send UDP packet to specific MAC address when the | |
372 | address is not yet configured, so must fall back to raw | |
373 | packets */ | |
374 | return dhcp_server_send_unicast_raw(server, packet, | |
375 | sizeof(DHCPPacket) + optoffset); | |
969b009d TG |
376 | } |
377 | ||
378 | int dhcp_server_send_packet(sd_dhcp_server *server, | |
379 | DHCPRequest *req, DHCPPacket *packet, | |
380 | int type, size_t optoffset) { | |
381 | be32_t destination = INADDR_ANY; | |
8eb7b6a5 | 382 | uint16_t destination_port = DHCP_PORT_CLIENT; |
969b009d TG |
383 | int r; |
384 | ||
385 | assert(server); | |
386 | assert(req); | |
387 | assert(req->max_optlen); | |
11c38d3e | 388 | assert(req->message); |
969b009d TG |
389 | assert(optoffset <= req->max_optlen); |
390 | assert(packet); | |
391 | ||
392 | r = dhcp_option_append(&packet->dhcp, req->max_optlen, &optoffset, 0, | |
22805d92 | 393 | SD_DHCP_OPTION_SERVER_IDENTIFIER, |
969b009d TG |
394 | 4, &server->address); |
395 | if (r < 0) | |
396 | return r; | |
397 | ||
11c38d3e YA |
398 | if (req->agent_info_option) { |
399 | size_t opt_full_length = *(req->agent_info_option + 1) + 2; | |
400 | /* there must be space left for SD_DHCP_OPTION_END */ | |
401 | if (optoffset + opt_full_length < req->max_optlen) { | |
402 | memcpy(packet->dhcp.options + optoffset, req->agent_info_option, opt_full_length); | |
403 | optoffset += opt_full_length; | |
404 | } | |
405 | } | |
406 | ||
969b009d | 407 | r = dhcp_option_append(&packet->dhcp, req->max_optlen, &optoffset, 0, |
22805d92 | 408 | SD_DHCP_OPTION_END, 0, NULL); |
969b009d TG |
409 | if (r < 0) |
410 | return r; | |
411 | ||
412 | /* RFC 2131 Section 4.1 | |
413 | ||
414 | If the ’giaddr’ field in a DHCP message from a client is non-zero, | |
415 | the server sends any return messages to the ’DHCP server’ port on the | |
416 | BOOTP relay agent whose address appears in ’giaddr’. If the ’giaddr’ | |
417 | field is zero and the ’ciaddr’ field is nonzero, then the server | |
418 | unicasts DHCPOFFER and DHCPACK messages to the address in ’ciaddr’. | |
419 | If ’giaddr’ is zero and ’ciaddr’ is zero, and the broadcast bit is | |
420 | set, then the server broadcasts DHCPOFFER and DHCPACK messages to | |
421 | 0xffffffff. If the broadcast bit is not set and ’giaddr’ is zero and | |
422 | ’ciaddr’ is zero, then the server unicasts DHCPOFFER and DHCPACK | |
423 | messages to the client’s hardware address and ’yiaddr’ address. In | |
424 | all cases, when ’giaddr’ is zero, the server broadcasts any DHCPNAK | |
425 | messages to 0xffffffff. | |
426 | ||
427 | Section 4.3.2 | |
428 | ||
429 | If ’giaddr’ is set in the DHCPREQUEST message, the client is on a | |
430 | different subnet. The server MUST set the broadcast bit in the | |
431 | DHCPNAK, so that the relay agent will broadcast the DHCPNAK to the | |
432 | client, because the client may not have a correct network address | |
433 | or subnet mask, and the client may not be answering ARP requests. | |
434 | */ | |
435 | if (req->message->giaddr) { | |
436 | destination = req->message->giaddr; | |
8eb7b6a5 | 437 | destination_port = DHCP_PORT_SERVER; |
969b009d TG |
438 | if (type == DHCP_NAK) |
439 | packet->dhcp.flags = htobe16(0x8000); | |
440 | } else if (req->message->ciaddr && type != DHCP_NAK) | |
441 | destination = req->message->ciaddr; | |
442 | ||
c95df587 YA |
443 | bool l2_broadcast = requested_broadcast(req->message) || type == DHCP_NAK; |
444 | return dhcp_server_send(server, destination, destination_port, packet, optoffset, l2_broadcast); | |
969b009d TG |
445 | } |
446 | ||
4dc35568 | 447 | static int server_message_init(sd_dhcp_server *server, DHCPPacket **ret, |
a6f1e036 TG |
448 | uint8_t type, size_t *_optoffset, |
449 | DHCPRequest *req) { | |
4dc35568 | 450 | _cleanup_free_ DHCPPacket *packet = NULL; |
1231c4d2 | 451 | size_t optoffset = 0; |
4dc35568 TG |
452 | int r; |
453 | ||
454 | assert(server); | |
455 | assert(ret); | |
456 | assert(_optoffset); | |
bd57b450 | 457 | assert(IN_SET(type, DHCP_OFFER, DHCP_ACK, DHCP_NAK)); |
4dc35568 TG |
458 | |
459 | packet = malloc0(sizeof(DHCPPacket) + req->max_optlen); | |
460 | if (!packet) | |
461 | return -ENOMEM; | |
462 | ||
a6f1e036 | 463 | r = dhcp_message_init(&packet->dhcp, BOOTREPLY, |
76253e73 DW |
464 | be32toh(req->message->xid), type, ARPHRD_ETHER, |
465 | req->max_optlen, &optoffset); | |
4dc35568 TG |
466 | if (r < 0) |
467 | return r; | |
468 | ||
469 | packet->dhcp.flags = req->message->flags; | |
470 | packet->dhcp.giaddr = req->message->giaddr; | |
471 | memcpy(&packet->dhcp.chaddr, &req->message->chaddr, ETH_ALEN); | |
472 | ||
473 | *_optoffset = optoffset; | |
1cc6c93a | 474 | *ret = TAKE_PTR(packet); |
4dc35568 TG |
475 | |
476 | return 0; | |
477 | } | |
478 | ||
986c0edf | 479 | static int server_send_offer_or_ack( |
ddb82ec2 LP |
480 | sd_dhcp_server *server, |
481 | DHCPRequest *req, | |
986c0edf YW |
482 | be32_t address, |
483 | uint8_t type) { | |
ddb82ec2 | 484 | |
2dead812 | 485 | _cleanup_free_ DHCPPacket *packet = NULL; |
7354900d | 486 | sd_dhcp_option *j; |
986c0edf | 487 | be32_t lease_time; |
564ca984 | 488 | size_t offset; |
2dead812 TG |
489 | int r; |
490 | ||
986c0edf YW |
491 | assert(server); |
492 | assert(req); | |
493 | assert(IN_SET(type, DHCP_OFFER, DHCP_ACK)); | |
494 | ||
495 | r = server_message_init(server, &packet, type, &offset, req); | |
2dead812 TG |
496 | if (r < 0) |
497 | return r; | |
498 | ||
499 | packet->dhcp.yiaddr = address; | |
500 | ||
c7d9ffe6 | 501 | lease_time = htobe32(req->lifetime); |
2dead812 | 502 | r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0, |
22805d92 | 503 | SD_DHCP_OPTION_IP_ADDRESS_LEASE_TIME, 4, |
a6f1e036 | 504 | &lease_time); |
2dead812 TG |
505 | if (r < 0) |
506 | return r; | |
507 | ||
59b8f6b6 | 508 | r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0, |
22805d92 | 509 | SD_DHCP_OPTION_SUBNET_MASK, 4, &server->netmask); |
59b8f6b6 TG |
510 | if (r < 0) |
511 | return r; | |
512 | ||
77ff6022 CG |
513 | if (server->emit_router) { |
514 | r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0, | |
515 | SD_DHCP_OPTION_ROUTER, 4, &server->address); | |
516 | if (r < 0) | |
517 | return r; | |
518 | } | |
59b8f6b6 | 519 | |
986c0edf YW |
520 | if (type == DHCP_ACK) { |
521 | static const uint8_t option_map[_SD_DHCP_LEASE_SERVER_TYPE_MAX] = { | |
522 | [SD_DHCP_LEASE_DNS] = SD_DHCP_OPTION_DOMAIN_NAME_SERVER, | |
523 | [SD_DHCP_LEASE_NTP] = SD_DHCP_OPTION_NTP_SERVER, | |
524 | [SD_DHCP_LEASE_SIP] = SD_DHCP_OPTION_SIP_SERVER, | |
525 | [SD_DHCP_LEASE_POP3] = SD_DHCP_OPTION_POP3_SERVER, | |
526 | [SD_DHCP_LEASE_SMTP] = SD_DHCP_OPTION_SMTP_SERVER, | |
527 | [SD_DHCP_LEASE_LPR] = SD_DHCP_OPTION_LPR_SERVER, | |
528 | }; | |
529 | ||
530 | for (sd_dhcp_lease_server_type_t k = 0; k < _SD_DHCP_LEASE_SERVER_TYPE_MAX; k++) { | |
531 | if (server->servers[k].size <= 0) | |
532 | continue; | |
533 | ||
534 | r = dhcp_option_append( | |
535 | &packet->dhcp, req->max_optlen, &offset, 0, | |
536 | option_map[k], | |
537 | sizeof(struct in_addr) * server->servers[k].size, | |
538 | server->servers[k].addr); | |
539 | if (r < 0) | |
540 | return r; | |
541 | } | |
2c649ca1 | 542 | |
50018bfa | 543 | |
986c0edf YW |
544 | if (server->timezone) { |
545 | r = dhcp_option_append( | |
546 | &packet->dhcp, req->max_optlen, &offset, 0, | |
547 | SD_DHCP_OPTION_NEW_TZDB_TIMEZONE, | |
548 | strlen(server->timezone), server->timezone); | |
549 | if (r < 0) | |
550 | return r; | |
551 | } | |
8eb9058d LP |
552 | } |
553 | ||
ebffea2a | 554 | ORDERED_SET_FOREACH(j, server->extra_options) { |
7354900d DW |
555 | r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0, |
556 | j->option, j->length, j->data); | |
557 | if (r < 0) | |
558 | return r; | |
559 | } | |
560 | ||
ebffea2a | 561 | if (!ordered_set_isempty(server->vendor_options)) { |
564ca984 SS |
562 | r = dhcp_option_append( |
563 | &packet->dhcp, req->max_optlen, &offset, 0, | |
564 | SD_DHCP_OPTION_VENDOR_SPECIFIC, | |
ebffea2a | 565 | ordered_set_size(server->vendor_options), server->vendor_options); |
564ca984 SS |
566 | if (r < 0) |
567 | return r; | |
568 | } | |
569 | ||
986c0edf | 570 | r = dhcp_server_send_packet(server, req, packet, type, offset); |
2dead812 TG |
571 | if (r < 0) |
572 | return r; | |
573 | ||
574 | return 0; | |
575 | } | |
576 | ||
bd57b450 TG |
577 | static int server_send_nak(sd_dhcp_server *server, DHCPRequest *req) { |
578 | _cleanup_free_ DHCPPacket *packet = NULL; | |
579 | size_t offset; | |
580 | int r; | |
581 | ||
582 | r = server_message_init(server, &packet, DHCP_NAK, &offset, req); | |
583 | if (r < 0) | |
584 | return r; | |
585 | ||
b3ec603c | 586 | return dhcp_server_send_packet(server, req, packet, DHCP_NAK, offset); |
bd57b450 TG |
587 | } |
588 | ||
a6f1e036 | 589 | static int server_send_forcerenew(sd_dhcp_server *server, be32_t address, |
141261f1 | 590 | be32_t gateway, const uint8_t chaddr[]) { |
52750344 TG |
591 | _cleanup_free_ DHCPPacket *packet = NULL; |
592 | size_t optoffset = 0; | |
593 | int r; | |
594 | ||
595 | assert(server); | |
596 | assert(address != INADDR_ANY); | |
597 | assert(chaddr); | |
598 | ||
599 | packet = malloc0(sizeof(DHCPPacket) + DHCP_MIN_OPTIONS_SIZE); | |
600 | if (!packet) | |
601 | return -ENOMEM; | |
602 | ||
603 | r = dhcp_message_init(&packet->dhcp, BOOTREPLY, 0, | |
76253e73 DW |
604 | DHCP_FORCERENEW, ARPHRD_ETHER, |
605 | DHCP_MIN_OPTIONS_SIZE, &optoffset); | |
52750344 TG |
606 | if (r < 0) |
607 | return r; | |
608 | ||
609 | r = dhcp_option_append(&packet->dhcp, DHCP_MIN_OPTIONS_SIZE, | |
22805d92 | 610 | &optoffset, 0, SD_DHCP_OPTION_END, 0, NULL); |
52750344 TG |
611 | if (r < 0) |
612 | return r; | |
613 | ||
614 | memcpy(&packet->dhcp.chaddr, chaddr, ETH_ALEN); | |
615 | ||
8eb7b6a5 PF |
616 | r = dhcp_server_send_udp(server, address, DHCP_PORT_CLIENT, |
617 | &packet->dhcp, | |
52750344 | 618 | sizeof(DHCPMessage) + optoffset); |
c15fb62a TA |
619 | if (r < 0) |
620 | return r; | |
52750344 TG |
621 | |
622 | return 0; | |
623 | } | |
624 | ||
b3ec603c | 625 | static int parse_request(uint8_t code, uint8_t len, const void *option, void *userdata) { |
89ca10c6 | 626 | DHCPRequest *req = userdata; |
816e2e7a TG |
627 | |
628 | assert(req); | |
629 | ||
630 | switch(code) { | |
22805d92 | 631 | case SD_DHCP_OPTION_IP_ADDRESS_LEASE_TIME: |
c7d9ffe6 | 632 | if (len == 4) |
9ae84244 | 633 | req->lifetime = unaligned_read_be32(option); |
c7d9ffe6 TG |
634 | |
635 | break; | |
22805d92 | 636 | case SD_DHCP_OPTION_REQUESTED_IP_ADDRESS: |
2dead812 | 637 | if (len == 4) |
9ae84244 | 638 | memcpy(&req->requested_ip, option, sizeof(be32_t)); |
2dead812 TG |
639 | |
640 | break; | |
22805d92 | 641 | case SD_DHCP_OPTION_SERVER_IDENTIFIER: |
816e2e7a | 642 | if (len == 4) |
9ae84244 | 643 | memcpy(&req->server_id, option, sizeof(be32_t)); |
816e2e7a TG |
644 | |
645 | break; | |
22805d92 | 646 | case SD_DHCP_OPTION_CLIENT_IDENTIFIER: |
816e2e7a TG |
647 | if (len >= 2) { |
648 | uint8_t *data; | |
649 | ||
650 | data = memdup(option, len); | |
651 | if (!data) | |
652 | return -ENOMEM; | |
653 | ||
654 | free(req->client_id.data); | |
655 | req->client_id.data = data; | |
656 | req->client_id.length = len; | |
657 | } | |
658 | ||
659 | break; | |
22805d92 | 660 | case SD_DHCP_OPTION_MAXIMUM_MESSAGE_SIZE: |
76a9d0f1 LP |
661 | |
662 | if (len == 2 && unaligned_read_be16(option) >= sizeof(DHCPPacket)) | |
9ae84244 | 663 | req->max_optlen = unaligned_read_be16(option) - sizeof(DHCPPacket); |
816e2e7a | 664 | |
11c38d3e YA |
665 | break; |
666 | case SD_DHCP_OPTION_RELAY_AGENT_INFORMATION: | |
667 | req->agent_info_option = (uint8_t*)option - 2; | |
668 | ||
816e2e7a TG |
669 | break; |
670 | } | |
671 | ||
672 | return 0; | |
673 | } | |
674 | ||
75db809a | 675 | static DHCPRequest* dhcp_request_free(DHCPRequest *req) { |
816e2e7a | 676 | if (!req) |
75db809a | 677 | return NULL; |
816e2e7a TG |
678 | |
679 | free(req->client_id.data); | |
75db809a | 680 | return mfree(req); |
816e2e7a TG |
681 | } |
682 | ||
683 | DEFINE_TRIVIAL_CLEANUP_FUNC(DHCPRequest*, dhcp_request_free); | |
816e2e7a | 684 | |
586ac6f7 | 685 | static int ensure_sane_request(sd_dhcp_server *server, DHCPRequest *req, DHCPMessage *message) { |
816e2e7a TG |
686 | assert(req); |
687 | assert(message); | |
688 | ||
689 | req->message = message; | |
690 | ||
e2acdb6b | 691 | /* set client id based on MAC address if client did not send an explicit |
a6f1e036 | 692 | one */ |
816e2e7a | 693 | if (!req->client_id.data) { |
9a0f246f | 694 | void *data; |
816e2e7a | 695 | |
9a0f246f | 696 | data = malloc0(ETH_ALEN + 1); |
816e2e7a TG |
697 | if (!data) |
698 | return -ENOMEM; | |
699 | ||
9a0f246f LP |
700 | ((uint8_t*) data)[0] = 0x01; |
701 | memcpy((uint8_t*) data + 1, &message->chaddr, ETH_ALEN); | |
702 | ||
816e2e7a TG |
703 | req->client_id.length = ETH_ALEN + 1; |
704 | req->client_id.data = data; | |
816e2e7a TG |
705 | } |
706 | ||
707 | if (req->max_optlen < DHCP_MIN_OPTIONS_SIZE) | |
708 | req->max_optlen = DHCP_MIN_OPTIONS_SIZE; | |
709 | ||
9a0f246f | 710 | if (req->lifetime <= 0) |
586ac6f7 LP |
711 | req->lifetime = MAX(1ULL, server->default_lease_time); |
712 | ||
713 | if (server->max_lease_time > 0 && req->lifetime > server->max_lease_time) | |
714 | req->lifetime = server->max_lease_time; | |
c7d9ffe6 | 715 | |
816e2e7a TG |
716 | return 0; |
717 | } | |
718 | ||
87322b3a TG |
719 | static int get_pool_offset(sd_dhcp_server *server, be32_t requested_ip) { |
720 | assert(server); | |
721 | ||
722 | if (!server->pool_size) | |
723 | return -EINVAL; | |
724 | ||
99634696 TG |
725 | if (be32toh(requested_ip) < (be32toh(server->subnet) | server->pool_offset) || |
726 | be32toh(requested_ip) >= (be32toh(server->subnet) | (server->pool_offset + server->pool_size))) | |
727 | return -ERANGE; | |
87322b3a | 728 | |
99634696 | 729 | return be32toh(requested_ip & ~server->netmask) - server->pool_offset; |
87322b3a TG |
730 | } |
731 | ||
11c38d3e YA |
732 | static int append_agent_information_option(sd_dhcp_server *server, DHCPMessage *message, size_t opt_length, size_t size) { |
733 | int r; | |
734 | size_t offset; | |
735 | ||
736 | assert(server); | |
737 | assert(message); | |
738 | ||
739 | r = dhcp_option_find_option(message->options, opt_length, SD_DHCP_OPTION_END, &offset); | |
740 | if (r < 0) | |
741 | return r; | |
742 | ||
743 | r = dhcp_option_append(message, size, &offset, 0, SD_DHCP_OPTION_RELAY_AGENT_INFORMATION, 0, server); | |
744 | if (r < 0) | |
745 | return r; | |
746 | ||
747 | r = dhcp_option_append(message, size, &offset, 0, SD_DHCP_OPTION_END, 0, NULL); | |
748 | if (r < 0) | |
749 | return r; | |
750 | return offset; | |
751 | } | |
752 | ||
753 | static int dhcp_server_relay_message(sd_dhcp_server *server, DHCPMessage *message, size_t opt_length, size_t buflen) { | |
c95df587 | 754 | _cleanup_free_ DHCPPacket *packet = NULL; |
11c38d3e | 755 | int r; |
c95df587 YA |
756 | |
757 | assert(server); | |
758 | assert(message); | |
759 | assert(sd_dhcp_server_is_in_relay_mode(server)); | |
760 | ||
761 | if (message->op == BOOTREQUEST) { | |
762 | log_dhcp_server(server, "(relay agent) BOOTREQUEST (0x%x)", be32toh(message->xid)); | |
763 | if (message->hops >= 16) | |
764 | return -ETIME; | |
765 | message->hops++; | |
766 | ||
767 | /* https://tools.ietf.org/html/rfc1542#section-4.1.1 */ | |
768 | if (message->giaddr == 0) | |
769 | message->giaddr = server->address; | |
770 | ||
11c38d3e YA |
771 | if (server->agent_circuit_id || server->agent_remote_id) { |
772 | r = append_agent_information_option(server, message, opt_length, buflen - sizeof(DHCPMessage)); | |
773 | if (r < 0) | |
774 | return log_dhcp_server_errno(server, r, "could not append relay option: %m"); | |
775 | opt_length = r; | |
776 | } | |
777 | ||
c95df587 YA |
778 | return dhcp_server_send_udp(server, server->relay_target.s_addr, DHCP_PORT_SERVER, message, sizeof(DHCPMessage) + opt_length); |
779 | } else if (message->op == BOOTREPLY) { | |
780 | log_dhcp_server(server, "(relay agent) BOOTREPLY (0x%x)", be32toh(message->xid)); | |
11c38d3e | 781 | if (message->giaddr != server->address) |
c95df587 | 782 | return log_dhcp_server_errno(server, SYNTHETIC_ERRNO(EBADMSG), |
11c38d3e | 783 | "(relay agent) BOOTREPLY giaddr mismatch, discarding"); |
c95df587 YA |
784 | |
785 | int message_type = dhcp_option_parse(message, sizeof(DHCPMessage) + opt_length, NULL, NULL, NULL); | |
786 | if (message_type < 0) | |
787 | return message_type; | |
788 | ||
789 | packet = malloc0(sizeof(DHCPPacket) + opt_length); | |
790 | if (!packet) | |
791 | return -ENOMEM; | |
792 | memcpy(&packet->dhcp, message, sizeof(DHCPMessage) + opt_length); | |
793 | ||
11c38d3e YA |
794 | r = dhcp_option_remove_option(packet->dhcp.options, opt_length, SD_DHCP_OPTION_RELAY_AGENT_INFORMATION); |
795 | if (r > 0) | |
796 | opt_length = r; | |
797 | ||
c95df587 YA |
798 | bool l2_broadcast = requested_broadcast(message) || message_type == DHCP_NAK; |
799 | const be32_t destination = message_type == DHCP_NAK ? INADDR_ANY : message->ciaddr; | |
800 | return dhcp_server_send(server, destination, DHCP_PORT_CLIENT, packet, opt_length, l2_broadcast); | |
801 | } | |
802 | return -EBADMSG; | |
803 | } | |
804 | ||
83cedf7a TG |
805 | #define HASH_KEY SD_ID128_MAKE(0d,1d,fe,bd,f1,24,bd,b3,47,f1,dd,6e,73,21,93,30) |
806 | ||
be077570 TG |
807 | int dhcp_server_handle_message(sd_dhcp_server *server, DHCPMessage *message, |
808 | size_t length) { | |
8e766630 | 809 | _cleanup_(dhcp_request_freep) DHCPRequest *req = NULL; |
f693e9b3 | 810 | _cleanup_free_ char *error_message = NULL; |
87322b3a | 811 | DHCPLease *existing_lease; |
816e2e7a | 812 | int type, r; |
be077570 TG |
813 | |
814 | assert(server); | |
815 | assert(message); | |
816 | ||
817 | if (message->op != BOOTREQUEST || | |
818 | message->htype != ARPHRD_ETHER || | |
819 | message->hlen != ETHER_ADDR_LEN) | |
820 | return 0; | |
821 | ||
816e2e7a TG |
822 | req = new0(DHCPRequest, 1); |
823 | if (!req) | |
824 | return -ENOMEM; | |
825 | ||
f693e9b3 | 826 | type = dhcp_option_parse(message, length, parse_request, req, &error_message); |
be077570 TG |
827 | if (type < 0) |
828 | return 0; | |
829 | ||
586ac6f7 | 830 | r = ensure_sane_request(server, req, message); |
816e2e7a TG |
831 | if (r < 0) |
832 | /* this only fails on critical errors */ | |
833 | return r; | |
834 | ||
a6f1e036 TG |
835 | existing_lease = hashmap_get(server->leases_by_client_id, |
836 | &req->client_id); | |
87322b3a | 837 | |
4dc35568 | 838 | switch(type) { |
9a0f246f LP |
839 | |
840 | case DHCP_DISCOVER: { | |
87322b3a TG |
841 | be32_t address = INADDR_ANY; |
842 | unsigned i; | |
2dead812 | 843 | |
4dc35568 TG |
844 | log_dhcp_server(server, "DISCOVER (0x%x)", |
845 | be32toh(req->message->xid)); | |
846 | ||
2dead812 TG |
847 | if (!server->pool_size) |
848 | /* no pool allocated */ | |
849 | return 0; | |
850 | ||
87322b3a TG |
851 | /* for now pick a random free address from the pool */ |
852 | if (existing_lease) | |
853 | address = existing_lease->address; | |
854 | else { | |
b826ab58 | 855 | struct siphash state; |
0cb3c286 | 856 | uint64_t hash; |
99634696 | 857 | uint32_t next_offer; |
83cedf7a TG |
858 | |
859 | /* even with no persistence of leases, we try to offer the same client | |
860 | the same IP address. we do this by using the hash of the client id | |
861 | as the offset into the pool of leases when finding the next free one */ | |
862 | ||
0cb3c286 | 863 | siphash24_init(&state, HASH_KEY.bytes); |
b826ab58 | 864 | client_id_hash_func(&req->client_id, &state); |
933f9cae | 865 | hash = htole64(siphash24_finalize(&state)); |
0cb3c286 | 866 | next_offer = hash % server->pool_size; |
83cedf7a | 867 | |
87322b3a | 868 | for (i = 0; i < server->pool_size; i++) { |
83cedf7a | 869 | if (!server->bound_leases[next_offer]) { |
99634696 | 870 | address = server->subnet | htobe32(server->pool_offset + next_offer); |
87322b3a | 871 | break; |
6408ba5f LP |
872 | } |
873 | ||
874 | next_offer = (next_offer + 1) % server->pool_size; | |
87322b3a TG |
875 | } |
876 | } | |
877 | ||
878 | if (address == INADDR_ANY) | |
879 | /* no free addresses left */ | |
880 | return 0; | |
2dead812 | 881 | |
986c0edf | 882 | r = server_send_offer_or_ack(server, req, address, DHCP_OFFER); |
6e741541 | 883 | if (r < 0) |
4dc35568 | 884 | /* this only fails on critical errors */ |
6e741541 | 885 | return log_dhcp_server_errno(server, r, "Could not send offer: %m"); |
be077570 | 886 | |
6e741541 LP |
887 | log_dhcp_server(server, "OFFER (0x%x)", be32toh(req->message->xid)); |
888 | return DHCP_OFFER; | |
4dc35568 | 889 | } |
5b34277c | 890 | case DHCP_DECLINE: |
f693e9b3 | 891 | log_dhcp_server(server, "DECLINE (0x%x): %s", be32toh(req->message->xid), strna(error_message)); |
5b34277c TG |
892 | |
893 | /* TODO: make sure we don't offer this address again */ | |
894 | ||
895 | return 1; | |
896 | ||
9a0f246f | 897 | case DHCP_REQUEST: { |
2dead812 | 898 | be32_t address; |
bd57b450 | 899 | bool init_reboot = false; |
87322b3a | 900 | int pool_offset; |
2dead812 TG |
901 | |
902 | /* see RFC 2131, section 4.3.2 */ | |
903 | ||
904 | if (req->server_id) { | |
905 | log_dhcp_server(server, "REQUEST (selecting) (0x%x)", | |
906 | be32toh(req->message->xid)); | |
907 | ||
908 | /* SELECTING */ | |
909 | if (req->server_id != server->address) | |
910 | /* client did not pick us */ | |
911 | return 0; | |
912 | ||
913 | if (req->message->ciaddr) | |
914 | /* this MUST be zero */ | |
915 | return 0; | |
916 | ||
917 | if (!req->requested_ip) | |
918 | /* this must be filled in with the yiaddr | |
919 | from the chosen OFFER */ | |
920 | return 0; | |
921 | ||
922 | address = req->requested_ip; | |
923 | } else if (req->requested_ip) { | |
924 | log_dhcp_server(server, "REQUEST (init-reboot) (0x%x)", | |
925 | be32toh(req->message->xid)); | |
926 | ||
927 | /* INIT-REBOOT */ | |
928 | if (req->message->ciaddr) | |
929 | /* this MUST be zero */ | |
930 | return 0; | |
931 | ||
bd57b450 | 932 | /* TODO: check more carefully if IP is correct */ |
2dead812 | 933 | address = req->requested_ip; |
bd57b450 | 934 | init_reboot = true; |
2dead812 TG |
935 | } else { |
936 | log_dhcp_server(server, "REQUEST (rebinding/renewing) (0x%x)", | |
937 | be32toh(req->message->xid)); | |
938 | ||
939 | /* REBINDING / RENEWING */ | |
940 | if (!req->message->ciaddr) | |
941 | /* this MUST be filled in with clients IP address */ | |
942 | return 0; | |
943 | ||
944 | address = req->message->ciaddr; | |
945 | } | |
946 | ||
87322b3a TG |
947 | pool_offset = get_pool_offset(server, address); |
948 | ||
949 | /* verify that the requested address is from the pool, and either | |
950 | owned by the current client or free */ | |
951 | if (pool_offset >= 0 && | |
952 | server->bound_leases[pool_offset] == existing_lease) { | |
953 | DHCPLease *lease; | |
a7f7d1bd | 954 | usec_t time_now = 0; |
87322b3a TG |
955 | |
956 | if (!existing_lease) { | |
957 | lease = new0(DHCPLease, 1); | |
357e1b17 LP |
958 | if (!lease) |
959 | return -ENOMEM; | |
28c78e07 | 960 | lease->address = address; |
87322b3a TG |
961 | lease->client_id.data = memdup(req->client_id.data, |
962 | req->client_id.length); | |
02557f97 TA |
963 | if (!lease->client_id.data) { |
964 | free(lease); | |
87322b3a | 965 | return -ENOMEM; |
02557f97 | 966 | } |
87322b3a | 967 | lease->client_id.length = req->client_id.length; |
a6f1e036 TG |
968 | memcpy(&lease->chaddr, &req->message->chaddr, |
969 | ETH_ALEN); | |
52750344 | 970 | lease->gateway = req->message->giaddr; |
87322b3a TG |
971 | } else |
972 | lease = existing_lease; | |
973 | ||
a6f1e036 TG |
974 | r = sd_event_now(server->event, |
975 | clock_boottime_or_monotonic(), | |
976 | &time_now); | |
bff92d2c SS |
977 | if (r < 0) { |
978 | if (!existing_lease) | |
979 | dhcp_lease_free(lease); | |
38a03f06 | 980 | return r; |
bff92d2c SS |
981 | } |
982 | ||
87322b3a TG |
983 | lease->expiration = req->lifetime * USEC_PER_SEC + time_now; |
984 | ||
986c0edf | 985 | r = server_send_offer_or_ack(server, req, address, DHCP_ACK); |
2dead812 TG |
986 | if (r < 0) { |
987 | /* this only fails on critical errors */ | |
6e741541 | 988 | log_dhcp_server_errno(server, r, "Could not send ack: %m"); |
87322b3a TG |
989 | |
990 | if (!existing_lease) | |
991 | dhcp_lease_free(lease); | |
992 | ||
2dead812 TG |
993 | return r; |
994 | } else { | |
995 | log_dhcp_server(server, "ACK (0x%x)", | |
996 | be32toh(req->message->xid)); | |
87322b3a TG |
997 | |
998 | server->bound_leases[pool_offset] = lease; | |
a6f1e036 TG |
999 | hashmap_put(server->leases_by_client_id, |
1000 | &lease->client_id, lease); | |
87322b3a | 1001 | |
36d35f22 MAL |
1002 | if (server->callback) |
1003 | server->callback(server, SD_DHCP_SERVER_EVENT_LEASE_CHANGED, server->callback_userdata); | |
1004 | ||
2dead812 TG |
1005 | return DHCP_ACK; |
1006 | } | |
6e741541 | 1007 | |
bd57b450 TG |
1008 | } else if (init_reboot) { |
1009 | r = server_send_nak(server, req); | |
6e741541 | 1010 | if (r < 0) |
bd57b450 | 1011 | /* this only fails on critical errors */ |
6e741541 LP |
1012 | return log_dhcp_server_errno(server, r, "Could not send nak: %m"); |
1013 | ||
1014 | log_dhcp_server(server, "NAK (0x%x)", be32toh(req->message->xid)); | |
1015 | return DHCP_NAK; | |
bd57b450 | 1016 | } |
2dead812 TG |
1017 | |
1018 | break; | |
1019 | } | |
9a0f246f | 1020 | |
500792d8 TG |
1021 | case DHCP_RELEASE: { |
1022 | int pool_offset; | |
1023 | ||
1024 | log_dhcp_server(server, "RELEASE (0x%x)", | |
1025 | be32toh(req->message->xid)); | |
1026 | ||
1027 | if (!existing_lease) | |
1028 | return 0; | |
1029 | ||
1030 | if (existing_lease->address != req->message->ciaddr) | |
1031 | return 0; | |
1032 | ||
1033 | pool_offset = get_pool_offset(server, req->message->ciaddr); | |
1034 | if (pool_offset < 0) | |
1035 | return 0; | |
1036 | ||
1037 | if (server->bound_leases[pool_offset] == existing_lease) { | |
1038 | server->bound_leases[pool_offset] = NULL; | |
1039 | hashmap_remove(server->leases_by_client_id, existing_lease); | |
1040 | dhcp_lease_free(existing_lease); | |
36d35f22 MAL |
1041 | |
1042 | if (server->callback) | |
1043 | server->callback(server, SD_DHCP_SERVER_EVENT_LEASE_CHANGED, server->callback_userdata); | |
c3922c0c | 1044 | } |
500792d8 | 1045 | |
c3922c0c LP |
1046 | return 0; |
1047 | }} | |
4dc35568 TG |
1048 | |
1049 | return 0; | |
be077570 TG |
1050 | } |
1051 | ||
11c38d3e YA |
1052 | static size_t relay_agent_information_length(const char* agent_circuit_id, const char* agent_remote_id) { |
1053 | size_t sum = 0; | |
1054 | if (agent_circuit_id) | |
1055 | sum += 2 + strlen(agent_circuit_id); | |
1056 | if (agent_remote_id) | |
1057 | sum += 2 + strlen(agent_remote_id); | |
1058 | return sum; | |
1059 | } | |
1060 | ||
ff734080 TG |
1061 | static int server_receive_message(sd_event_source *s, int fd, |
1062 | uint32_t revents, void *userdata) { | |
be077570 | 1063 | _cleanup_free_ DHCPMessage *message = NULL; |
fb29cdbe | 1064 | CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct in_pktinfo))) control; |
ff734080 TG |
1065 | sd_dhcp_server *server = userdata; |
1066 | struct iovec iov = {}; | |
1067 | struct msghdr msg = { | |
1068 | .msg_iov = &iov, | |
1069 | .msg_iovlen = 1, | |
fb29cdbe LP |
1070 | .msg_control = &control, |
1071 | .msg_controllen = sizeof(control), | |
ff734080 | 1072 | }; |
3a864fe4 | 1073 | struct cmsghdr *cmsg; |
11c38d3e | 1074 | ssize_t datagram_size, len; |
57027d03 | 1075 | int r; |
ff734080 TG |
1076 | |
1077 | assert(server); | |
1078 | ||
11c38d3e YA |
1079 | datagram_size = next_datagram_size_fd(fd); |
1080 | if (datagram_size < 0) | |
1081 | return datagram_size; | |
1082 | ||
1083 | size_t buflen = datagram_size; | |
1084 | if (sd_dhcp_server_is_in_relay_mode(server)) | |
1085 | /* Preallocate the additional size for DHCP Relay Agent Information Option if neeeded */ | |
1086 | buflen += relay_agent_information_length(server->agent_circuit_id, server->agent_remote_id) + 2; | |
ff734080 | 1087 | |
0d43d2fc | 1088 | message = malloc(buflen); |
ff734080 TG |
1089 | if (!message) |
1090 | return -ENOMEM; | |
1091 | ||
11c38d3e | 1092 | iov = IOVEC_MAKE(message, datagram_size); |
ff734080 | 1093 | |
2efa5bc6 LP |
1094 | len = recvmsg_safe(fd, &msg, 0); |
1095 | if (IN_SET(len, -EAGAIN, -EINTR)) | |
1096 | return 0; | |
1097 | if (len < 0) | |
1098 | return len; | |
1099 | if ((size_t) len < sizeof(DHCPMessage)) | |
be077570 | 1100 | return 0; |
ff734080 | 1101 | |
2a1288ff | 1102 | CMSG_FOREACH(cmsg, &msg) { |
3a864fe4 TG |
1103 | if (cmsg->cmsg_level == IPPROTO_IP && |
1104 | cmsg->cmsg_type == IP_PKTINFO && | |
1105 | cmsg->cmsg_len == CMSG_LEN(sizeof(struct in_pktinfo))) { | |
1106 | struct in_pktinfo *info = (struct in_pktinfo*)CMSG_DATA(cmsg); | |
1107 | ||
a6f1e036 TG |
1108 | /* TODO figure out if this can be done as a filter on |
1109 | * the socket, like for IPv6 */ | |
b3ec603c | 1110 | if (server->ifindex != info->ipi_ifindex) |
3a864fe4 TG |
1111 | return 0; |
1112 | ||
1113 | break; | |
1114 | } | |
1115 | } | |
1116 | ||
c95df587 | 1117 | if (sd_dhcp_server_is_in_relay_mode(server)) { |
11c38d3e | 1118 | r = dhcp_server_relay_message(server, message, len - sizeof(DHCPMessage), buflen); |
c95df587 YA |
1119 | if (r < 0) |
1120 | log_dhcp_server_errno(server, r, "Couldn't relay message: %m"); | |
1121 | } else { | |
1122 | r = dhcp_server_handle_message(server, message, (size_t) len); | |
1123 | if (r < 0) | |
1124 | log_dhcp_server_errno(server, r, "Couldn't process incoming message: %m"); | |
1125 | } | |
57027d03 | 1126 | return 0; |
ff734080 TG |
1127 | } |
1128 | ||
1129 | int sd_dhcp_server_start(sd_dhcp_server *server) { | |
1130 | int r; | |
1131 | ||
1132 | assert_return(server, -EINVAL); | |
1133 | assert_return(server->event, -EINVAL); | |
1134 | assert_return(!server->receive_message, -EBUSY); | |
cfcbb135 LP |
1135 | assert_return(server->fd_raw < 0, -EBUSY); |
1136 | assert_return(server->fd < 0, -EBUSY); | |
20af7091 | 1137 | assert_return(server->address != htobe32(INADDR_ANY), -EUNATCH); |
ff734080 | 1138 | |
3e29b889 | 1139 | r = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0); |
8de4a226 TG |
1140 | if (r < 0) { |
1141 | r = -errno; | |
21b6b87e | 1142 | goto on_error; |
8de4a226 TG |
1143 | } |
1144 | server->fd_raw = r; | |
1145 | ||
21b6b87e YA |
1146 | if (server->bind_to_interface) |
1147 | r = dhcp_network_bind_udp_socket(server->ifindex, INADDR_ANY, DHCP_PORT_SERVER, -1); | |
1148 | else | |
1149 | r = dhcp_network_bind_udp_socket(0, server->address, DHCP_PORT_SERVER, -1); | |
1150 | if (r < 0) | |
1151 | goto on_error; | |
ff734080 TG |
1152 | server->fd = r; |
1153 | ||
1154 | r = sd_event_add_io(server->event, &server->receive_message, | |
1155 | server->fd, EPOLLIN, | |
1156 | server_receive_message, server); | |
21b6b87e YA |
1157 | if (r < 0) |
1158 | goto on_error; | |
ff734080 TG |
1159 | |
1160 | r = sd_event_source_set_priority(server->receive_message, | |
1161 | server->event_priority); | |
21b6b87e YA |
1162 | if (r < 0) |
1163 | goto on_error; | |
1164 | ||
1165 | if (!server->bind_to_interface) { | |
1166 | r = dhcp_network_bind_udp_socket(server->ifindex, INADDR_BROADCAST, DHCP_PORT_SERVER, -1); | |
1167 | if (r < 0) | |
1168 | goto on_error; | |
1169 | ||
1170 | server->fd_broadcast = r; | |
1171 | ||
1172 | r = sd_event_add_io(server->event, &server->receive_broadcast, | |
1173 | server->fd_broadcast, EPOLLIN, | |
1174 | server_receive_message, server); | |
1175 | if (r < 0) | |
1176 | goto on_error; | |
1177 | ||
1178 | r = sd_event_source_set_priority(server->receive_broadcast, | |
1179 | server->event_priority); | |
1180 | if (r < 0) | |
1181 | goto on_error; | |
ff734080 TG |
1182 | } |
1183 | ||
1184 | log_dhcp_server(server, "STARTED"); | |
1185 | ||
1186 | return 0; | |
21b6b87e YA |
1187 | |
1188 | on_error: | |
1189 | sd_dhcp_server_stop(server); | |
1190 | return r; | |
ff734080 | 1191 | } |
52750344 TG |
1192 | |
1193 | int sd_dhcp_server_forcerenew(sd_dhcp_server *server) { | |
621ac3d2 | 1194 | int r = 0; |
52750344 TG |
1195 | |
1196 | assert_return(server, -EINVAL); | |
1197 | assert(server->bound_leases); | |
1198 | ||
fe96c0f8 | 1199 | for (uint32_t i = 0; i < server->pool_size; i++) { |
52750344 TG |
1200 | DHCPLease *lease = server->bound_leases[i]; |
1201 | ||
99634696 | 1202 | if (!lease || lease == &server->invalid_lease) |
52750344 TG |
1203 | continue; |
1204 | ||
1205 | r = server_send_forcerenew(server, lease->address, | |
1206 | lease->gateway, | |
1207 | lease->chaddr); | |
1208 | if (r < 0) | |
1209 | return r; | |
6408ba5f LP |
1210 | |
1211 | log_dhcp_server(server, "FORCERENEW"); | |
52750344 TG |
1212 | } |
1213 | ||
1214 | return r; | |
1215 | } | |
8eb9058d | 1216 | |
21b6b87e YA |
1217 | int sd_dhcp_server_set_bind_to_interface(sd_dhcp_server *server, int enabled) { |
1218 | assert_return(server, -EINVAL); | |
1219 | assert_return(!sd_dhcp_server_is_running(server), -EBUSY); | |
1220 | ||
1221 | if (!!enabled == server->bind_to_interface) | |
1222 | return 0; | |
1223 | ||
1224 | server->bind_to_interface = enabled; | |
1225 | ||
1226 | return 1; | |
1227 | } | |
1228 | ||
64d6c229 | 1229 | int sd_dhcp_server_set_timezone(sd_dhcp_server *server, const char *tz) { |
8eb9058d LP |
1230 | int r; |
1231 | ||
1232 | assert_return(server, -EINVAL); | |
089fb865 | 1233 | assert_return(timezone_is_valid(tz, LOG_DEBUG), -EINVAL); |
8eb9058d | 1234 | |
64d6c229 | 1235 | if (streq_ptr(tz, server->timezone)) |
8eb9058d LP |
1236 | return 0; |
1237 | ||
64d6c229 | 1238 | r = free_and_strdup(&server->timezone, tz); |
8eb9058d LP |
1239 | if (r < 0) |
1240 | return r; | |
1241 | ||
1242 | return 1; | |
1243 | } | |
586ac6f7 LP |
1244 | |
1245 | int sd_dhcp_server_set_max_lease_time(sd_dhcp_server *server, uint32_t t) { | |
1246 | assert_return(server, -EINVAL); | |
1247 | ||
1248 | if (t == server->max_lease_time) | |
1249 | return 0; | |
1250 | ||
1251 | server->max_lease_time = t; | |
1252 | return 1; | |
1253 | } | |
1254 | ||
1255 | int sd_dhcp_server_set_default_lease_time(sd_dhcp_server *server, uint32_t t) { | |
1256 | assert_return(server, -EINVAL); | |
1257 | ||
1258 | if (t == server->default_lease_time) | |
1259 | return 0; | |
1260 | ||
1261 | server->default_lease_time = t; | |
1262 | return 1; | |
1263 | } | |
1a04db0f | 1264 | |
c8407baf ZJS |
1265 | int sd_dhcp_server_set_servers( |
1266 | sd_dhcp_server *server, | |
2324fd3a | 1267 | sd_dhcp_lease_server_type_t what, |
c8407baf | 1268 | const struct in_addr addresses[], |
90810f7a | 1269 | size_t n_addresses) { |
1a04db0f | 1270 | |
ddb82ec2 LP |
1271 | struct in_addr *c = NULL; |
1272 | ||
1a04db0f | 1273 | assert_return(server, -EINVAL); |
c8407baf | 1274 | assert_return(addresses || n_addresses == 0, -EINVAL); |
ddb82ec2 LP |
1275 | assert_return(what >= 0, -EINVAL); |
1276 | assert_return(what < _SD_DHCP_LEASE_SERVER_TYPE_MAX, -EINVAL); | |
1a04db0f | 1277 | |
ddb82ec2 LP |
1278 | if (server->servers[what].size == n_addresses && |
1279 | memcmp(server->servers[what].addr, addresses, sizeof(struct in_addr) * n_addresses) == 0) | |
f678ac7e SS |
1280 | return 0; |
1281 | ||
c8407baf ZJS |
1282 | if (n_addresses > 0) { |
1283 | c = newdup(struct in_addr, addresses, n_addresses); | |
f678ac7e SS |
1284 | if (!c) |
1285 | return -ENOMEM; | |
f678ac7e SS |
1286 | } |
1287 | ||
ddb82ec2 LP |
1288 | free(server->servers[what].addr); |
1289 | server->servers[what].addr = c; | |
1290 | server->servers[what].size = n_addresses; | |
f678ac7e SS |
1291 | return 1; |
1292 | } | |
1293 | ||
90810f7a | 1294 | int sd_dhcp_server_set_dns(sd_dhcp_server *server, const struct in_addr dns[], size_t n) { |
ddb82ec2 | 1295 | return sd_dhcp_server_set_servers(server, SD_DHCP_LEASE_DNS, dns, n); |
c8407baf | 1296 | } |
90810f7a | 1297 | int sd_dhcp_server_set_ntp(sd_dhcp_server *server, const struct in_addr ntp[], size_t n) { |
ddb82ec2 | 1298 | return sd_dhcp_server_set_servers(server, SD_DHCP_LEASE_NTP, ntp, n); |
c8407baf | 1299 | } |
90810f7a | 1300 | int sd_dhcp_server_set_sip(sd_dhcp_server *server, const struct in_addr sip[], size_t n) { |
ddb82ec2 | 1301 | return sd_dhcp_server_set_servers(server, SD_DHCP_LEASE_SIP, sip, n); |
c8407baf | 1302 | } |
90810f7a | 1303 | int sd_dhcp_server_set_pop3(sd_dhcp_server *server, const struct in_addr pop3[], size_t n) { |
ddb82ec2 | 1304 | return sd_dhcp_server_set_servers(server, SD_DHCP_LEASE_POP3, pop3, n); |
c8407baf | 1305 | } |
90810f7a | 1306 | int sd_dhcp_server_set_smtp(sd_dhcp_server *server, const struct in_addr smtp[], size_t n) { |
ddb82ec2 | 1307 | return sd_dhcp_server_set_servers(server, SD_DHCP_LEASE_SMTP, smtp, n); |
2c649ca1 | 1308 | } |
90810f7a | 1309 | int sd_dhcp_server_set_lpr(sd_dhcp_server *server, const struct in_addr lpr[], size_t n) { |
ddb82ec2 | 1310 | return sd_dhcp_server_set_servers(server, SD_DHCP_LEASE_LPR, lpr, n); |
50018bfa | 1311 | } |
2c649ca1 | 1312 | |
77ff6022 CG |
1313 | int sd_dhcp_server_set_emit_router(sd_dhcp_server *server, int enabled) { |
1314 | assert_return(server, -EINVAL); | |
1315 | ||
1316 | if (enabled == server->emit_router) | |
1317 | return 0; | |
1318 | ||
1319 | server->emit_router = enabled; | |
1320 | ||
1321 | return 1; | |
1322 | } | |
564ca984 | 1323 | |
461dbb2f | 1324 | int sd_dhcp_server_add_option(sd_dhcp_server *server, sd_dhcp_option *v) { |
564ca984 SS |
1325 | int r; |
1326 | ||
1327 | assert_return(server, -EINVAL); | |
1328 | assert_return(v, -EINVAL); | |
1329 | ||
ebffea2a | 1330 | r = ordered_set_ensure_put(&server->extra_options, &dhcp_option_hash_ops, v); |
7354900d DW |
1331 | if (r < 0) |
1332 | return r; | |
1333 | ||
1334 | sd_dhcp_option_ref(v); | |
1335 | return 0; | |
1336 | } | |
1337 | ||
1338 | int sd_dhcp_server_add_vendor_option(sd_dhcp_server *server, sd_dhcp_option *v) { | |
1339 | int r; | |
1340 | ||
1341 | assert_return(server, -EINVAL); | |
1342 | assert_return(v, -EINVAL); | |
1343 | ||
ebffea2a | 1344 | r = ordered_set_ensure_put(&server->vendor_options, &dhcp_option_hash_ops, v); |
564ca984 SS |
1345 | if (r < 0) |
1346 | return r; | |
1347 | ||
461dbb2f | 1348 | sd_dhcp_option_ref(v); |
564ca984 SS |
1349 | |
1350 | return 1; | |
1351 | } | |
5b03043a MAL |
1352 | |
1353 | int sd_dhcp_server_set_callback(sd_dhcp_server *server, sd_dhcp_server_callback_t cb, void *userdata) { | |
1354 | assert_return(server, -EINVAL); | |
1355 | ||
1356 | server->callback = cb; | |
1357 | server->callback_userdata = userdata; | |
1358 | ||
1359 | return 0; | |
1360 | } | |
c95df587 | 1361 | |
11c38d3e | 1362 | int sd_dhcp_server_set_relay_target(sd_dhcp_server *server, const struct in_addr *address) { |
c95df587 YA |
1363 | assert_return(server, -EINVAL); |
1364 | assert_return(!sd_dhcp_server_is_running(server), -EBUSY); | |
1365 | ||
1366 | if (memcmp(address, &server->relay_target, sizeof(struct in_addr)) == 0) | |
1367 | return 0; | |
1368 | ||
1369 | server->relay_target = *address; | |
1370 | return 1; | |
1371 | } | |
11c38d3e YA |
1372 | |
1373 | int sd_dhcp_server_set_relay_agent_information( | |
1374 | sd_dhcp_server *server, | |
1375 | const char *agent_circuit_id, | |
1376 | const char *agent_remote_id) { | |
1377 | _cleanup_free_ char *circuit_id_dup = NULL, *remote_id_dup = NULL; | |
1378 | ||
1379 | assert_return(server, -EINVAL); | |
1380 | ||
1381 | if (relay_agent_information_length(agent_circuit_id, agent_remote_id) > UINT8_MAX) | |
1382 | return -ENOBUFS; | |
1383 | ||
1384 | if (agent_circuit_id) { | |
1385 | circuit_id_dup = strdup(agent_circuit_id); | |
1386 | if (!circuit_id_dup) | |
1387 | return -ENOMEM; | |
1388 | } | |
1389 | ||
1390 | if (agent_remote_id) { | |
1391 | remote_id_dup = strdup(agent_remote_id); | |
1392 | if (!remote_id_dup) | |
1393 | return -ENOMEM; | |
1394 | } | |
1395 | ||
1396 | free_and_replace(server->agent_circuit_id, circuit_id_dup); | |
1397 | free_and_replace(server->agent_remote_id, remote_id_dup); | |
1398 | return 0; | |
1399 | } |