1 /*
2  * efi_selftest_snp
3  *
4  * Copyright (c) 2017 Heinrich Schuchardt <xypron.glpk@gmx.de>
5  *
6  * SPDX-License-Identifier:	GPL-2.0+
7  *
8  * This unit test covers the Simple Network Protocol as well as
9  * the CopyMem and SetMem boottime services.
10  *
11  * A DHCP discover message is sent. The test is successful if a
12  * DHCP reply is received.
13  *
14  * TODO: Once ConnectController and DisconnectController are implemented
15  *	 we should connect our code as controller.
16  */
17 
18 #include <efi_selftest.h>
19 
20 /*
21  * MAC address for broadcasts
22  */
23 static const u8 BROADCAST_MAC[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
24 
25 struct dhcp_hdr {
26 	u8 op;
27 #define BOOTREQUEST 1
28 #define BOOTREPLY 2
29 	u8 htype;
30 # define HWT_ETHER 1
31 	u8 hlen;
32 # define HWL_ETHER 6
33 	u8 hops;
34 	u32 xid;
35 	u16 secs;
36 	u16 flags;
37 #define DHCP_FLAGS_UNICAST	0x0000
38 #define DHCP_FLAGS_BROADCAST	0x0080
39 	u32 ciaddr;
40 	u32 yiaddr;
41 	u32 siaddr;
42 	u32 giaddr;
43 	u8 chaddr[16];
44 	u8 sname[64];
45 	u8 file[128];
46 };
47 
48 /*
49  * Message type option.
50  */
51 #define DHCP_MESSAGE_TYPE	0x35
52 #define DHCPDISCOVER		1
53 #define DHCPOFFER		2
54 #define DHCPREQUEST		3
55 #define DHCPDECLINE		4
56 #define DHCPACK			5
57 #define DHCPNAK			6
58 #define DHCPRELEASE		7
59 
60 struct dhcp {
61 	struct ethernet_hdr eth_hdr;
62 	struct ip_udp_hdr ip_udp;
63 	struct dhcp_hdr dhcp_hdr;
64 	u8 opt[128];
65 } __packed;
66 
67 static struct efi_boot_services *boottime;
68 static struct efi_simple_network *net;
69 static struct efi_event *timer;
70 static const efi_guid_t efi_net_guid = EFI_SIMPLE_NETWORK_GUID;
71 /* IP packet ID */
72 static unsigned int net_ip_id;
73 
74 /*
75  * Compute the checksum of the IP header. We cover even values of length only.
76  * We cannot use net/checksum.c due to different CFLAGS values.
77  *
78  * @buf:	IP header
79  * @len:	length of header in bytes
80  * @return:	checksum
81  */
82 static unsigned int efi_ip_checksum(const void *buf, size_t len)
83 {
84 	size_t i;
85 	u32 sum = 0;
86 	const u16 *pos = buf;
87 
88 	for (i = 0; i < len; i += 2)
89 		sum += *pos++;
90 
91 	sum = (sum >> 16) + (sum & 0xffff);
92 	sum += sum >> 16;
93 	sum = ~sum & 0xffff;
94 
95 	return sum;
96 }
97 
98 /*
99  * Transmit a DHCPDISCOVER message.
100  */
101 static efi_status_t send_dhcp_discover(void)
102 {
103 	efi_status_t ret;
104 	struct dhcp p = {};
105 
106 	/*
107 	 * Fill ethernet header
108 	 */
109 	boottime->copy_mem(p.eth_hdr.et_dest, (void *)BROADCAST_MAC, ARP_HLEN);
110 	boottime->copy_mem(p.eth_hdr.et_src, &net->mode->current_address,
111 			   ARP_HLEN);
112 	p.eth_hdr.et_protlen = htons(PROT_IP);
113 	/*
114 	 * Fill IP header
115 	 */
116 	p.ip_udp.ip_hl_v	= 0x45;
117 	p.ip_udp.ip_len		= htons(sizeof(struct dhcp) -
118 					sizeof(struct ethernet_hdr));
119 	p.ip_udp.ip_id		= htons(++net_ip_id);
120 	p.ip_udp.ip_off		= htons(IP_FLAGS_DFRAG);
121 	p.ip_udp.ip_ttl		= 0xff; /* time to live */
122 	p.ip_udp.ip_p		= IPPROTO_UDP;
123 	boottime->set_mem(&p.ip_udp.ip_dst, 4, 0xff);
124 	p.ip_udp.ip_sum		= efi_ip_checksum(&p.ip_udp, IP_HDR_SIZE);
125 
126 	/*
127 	 * Fill UDP header
128 	 */
129 	p.ip_udp.udp_src	= htons(68);
130 	p.ip_udp.udp_dst	= htons(67);
131 	p.ip_udp.udp_len	= htons(sizeof(struct dhcp) -
132 					sizeof(struct ethernet_hdr) -
133 					sizeof(struct ip_hdr));
134 	/*
135 	 * Fill DHCP header
136 	 */
137 	p.dhcp_hdr.op		= BOOTREQUEST;
138 	p.dhcp_hdr.htype	= HWT_ETHER;
139 	p.dhcp_hdr.hlen		= HWL_ETHER;
140 	p.dhcp_hdr.flags	= htons(DHCP_FLAGS_UNICAST);
141 	boottime->copy_mem(&p.dhcp_hdr.chaddr,
142 			   &net->mode->current_address, ARP_HLEN);
143 	/*
144 	 * Fill options
145 	 */
146 	p.opt[0]	= 0x63; /* DHCP magic cookie */
147 	p.opt[1]	= 0x82;
148 	p.opt[2]	= 0x53;
149 	p.opt[3]	= 0x63;
150 	p.opt[4]	= DHCP_MESSAGE_TYPE;
151 	p.opt[5]	= 0x01; /* length */
152 	p.opt[6]	= DHCPDISCOVER;
153 	p.opt[7]	= 0x39; /* maximum message size */
154 	p.opt[8]	= 0x02; /* length */
155 	p.opt[9]	= 0x02; /* 576 bytes */
156 	p.opt[10]	= 0x40;
157 	p.opt[11]	= 0xff; /* end of options */
158 
159 	/*
160 	 * Transmit DHCPDISCOVER message.
161 	 */
162 	ret = net->transmit(net, 0, sizeof(struct dhcp), &p, NULL, NULL, 0);
163 	if (ret != EFI_SUCCESS)
164 		efi_st_error("Sending a DHCP request failed\n");
165 	else
166 		efi_st_printf("DHCP Discover\n");
167 	return ret;
168 }
169 
170 /*
171  * Setup unit test.
172  *
173  * Create a 1 s periodic timer.
174  * Start the network driver.
175  *
176  * @handle:	handle of the loaded image
177  * @systable:	system table
178  * @return:	EFI_ST_SUCCESS for success
179  */
180 static int setup(const efi_handle_t handle,
181 		 const struct efi_system_table *systable)
182 {
183 	efi_status_t ret;
184 
185 	boottime = systable->boottime;
186 
187 	/*
188 	 * Create a timer event.
189 	 */
190 	ret = boottime->create_event(EVT_TIMER, TPL_CALLBACK, NULL, NULL,
191 				     &timer);
192 	if (ret != EFI_SUCCESS) {
193 		efi_st_error("Failed to create event\n");
194 		return EFI_ST_FAILURE;
195 	}
196 	/*
197 	 * Set timer period to 1s.
198 	 */
199 	ret = boottime->set_timer(timer, EFI_TIMER_PERIODIC, 10000000);
200 	if (ret != EFI_SUCCESS) {
201 		efi_st_error("Failed to set timer\n");
202 		return EFI_ST_FAILURE;
203 	}
204 	/*
205 	 * Find an interface implementing the SNP protocol.
206 	 */
207 	ret = boottime->locate_protocol(&efi_net_guid, NULL, (void **)&net);
208 	if (ret != EFI_SUCCESS) {
209 		net = NULL;
210 		efi_st_error("Failed to locate simple network protocol\n");
211 		return EFI_ST_FAILURE;
212 	}
213 	/*
214 	 * Check hardware address size.
215 	 */
216 	if (!net->mode) {
217 		efi_st_error("Mode not provided\n");
218 		return EFI_ST_FAILURE;
219 	}
220 	if (net->mode->hwaddr_size != ARP_HLEN) {
221 		efi_st_error("HwAddressSize = %u, expected %u\n",
222 			     net->mode->hwaddr_size, ARP_HLEN);
223 		return EFI_ST_FAILURE;
224 	}
225 	/*
226 	 * Check that WaitForPacket event exists.
227 	 */
228 	if (!net->wait_for_packet) {
229 		efi_st_error("WaitForPacket event missing\n");
230 		return EFI_ST_FAILURE;
231 	}
232 	/*
233 	 * Initialize network adapter.
234 	 */
235 	ret = net->initialize(net, 0, 0);
236 	if (ret != EFI_SUCCESS) {
237 		efi_st_error("Failed to initialize network adapter\n");
238 		return EFI_ST_FAILURE;
239 	}
240 	/*
241 	 * Start network adapter.
242 	 */
243 	ret = net->start(net);
244 	if (ret != EFI_SUCCESS) {
245 		efi_st_error("Failed to start network adapter\n");
246 		return EFI_ST_FAILURE;
247 	}
248 	return EFI_ST_SUCCESS;
249 }
250 
251 /*
252  * Execute unit test.
253  *
254  * A DHCP discover message is sent. The test is successful if a
255  * DHCP reply is received within 10 seconds.
256  *
257  * @return:	EFI_ST_SUCCESS for success
258  */
259 static int execute(void)
260 {
261 	efi_status_t ret;
262 	struct efi_event *events[2];
263 	size_t index;
264 	union {
265 		struct dhcp p;
266 		u8 b[PKTSIZE];
267 	} buffer;
268 	struct efi_mac_address srcaddr;
269 	struct efi_mac_address destaddr;
270 	size_t buffer_size;
271 	u8 *addr;
272 	/*
273 	 * The timeout is to occur after 10 s.
274 	 */
275 	unsigned int timeout = 10;
276 
277 	/* Setup may have failed */
278 	if (!net || !timer) {
279 		efi_st_error("Cannot execute test after setup failure\n");
280 		return EFI_ST_FAILURE;
281 	}
282 
283 	/*
284 	 * Send DHCP discover message
285 	 */
286 	ret = send_dhcp_discover();
287 	if (ret != EFI_SUCCESS)
288 		return EFI_ST_FAILURE;
289 
290 	/*
291 	 * If we would call WaitForEvent only with the WaitForPacket event,
292 	 * our code would block until a packet is received which might never
293 	 * occur. By calling WaitFor event with both a timer event and the
294 	 * WaitForPacket event we can escape this blocking situation.
295 	 *
296 	 * If the timer event occurs before we have received a DHCP reply
297 	 * a further DHCP discover message is sent.
298 	 */
299 	events[0] = timer;
300 	events[1] = net->wait_for_packet;
301 	for (;;) {
302 		/*
303 		 * Wait for packet to be received or timer event.
304 		 */
305 		boottime->wait_for_event(2, events, &index);
306 		if (index == 0) {
307 			/*
308 			 * The timer event occurred. Check for timeout.
309 			 */
310 			--timeout;
311 			if (!timeout) {
312 				efi_st_error("Timeout occurred\n");
313 				return EFI_ST_FAILURE;
314 			}
315 			/*
316 			 * Send further DHCP discover message
317 			 */
318 			ret = send_dhcp_discover();
319 			if (ret != EFI_SUCCESS)
320 				return EFI_ST_FAILURE;
321 			continue;
322 		}
323 		/*
324 		 * Receive packet
325 		 */
326 		buffer_size = sizeof(buffer);
327 		net->receive(net, NULL, &buffer_size, &buffer,
328 			     &srcaddr, &destaddr, NULL);
329 		if (ret != EFI_SUCCESS) {
330 			efi_st_error("Failed to receive packet");
331 			return EFI_ST_FAILURE;
332 		}
333 		/*
334 		 * Check the packet is meant for this system.
335 		 * Unfortunately QEMU ignores the broadcast flag.
336 		 * So we have to check for broadcasts too.
337 		 */
338 		if (efi_st_memcmp(&destaddr, &net->mode->current_address,
339 				  ARP_HLEN) &&
340 		    efi_st_memcmp(&destaddr, BROADCAST_MAC, ARP_HLEN))
341 			continue;
342 		/*
343 		 * Check this is a DHCP reply
344 		 */
345 		if (buffer.p.eth_hdr.et_protlen != ntohs(PROT_IP) ||
346 		    buffer.p.ip_udp.ip_hl_v != 0x45 ||
347 		    buffer.p.ip_udp.ip_p != IPPROTO_UDP ||
348 		    buffer.p.ip_udp.udp_src != ntohs(67) ||
349 		    buffer.p.ip_udp.udp_dst != ntohs(68) ||
350 		    buffer.p.dhcp_hdr.op != BOOTREPLY)
351 			continue;
352 		/*
353 		 * We successfully received a DHCP reply.
354 		 */
355 		break;
356 	}
357 
358 	/*
359 	 * Write a log message.
360 	 */
361 	addr = (u8 *)&buffer.p.ip_udp.ip_src;
362 	efi_st_printf("DHCP reply received from %u.%u.%u.%u (%pm) ",
363 		      addr[0], addr[1], addr[2], addr[3], &srcaddr);
364 	if (!efi_st_memcmp(&destaddr, BROADCAST_MAC, ARP_HLEN))
365 		efi_st_printf("as broadcast message.\n");
366 	else
367 		efi_st_printf("as unicast message.\n");
368 
369 	return EFI_ST_SUCCESS;
370 }
371 
372 /*
373  * Tear down unit test.
374  *
375  * Close the timer event created in setup.
376  * Shut down the network adapter.
377  *
378  * @return:	EFI_ST_SUCCESS for success
379  */
380 static int teardown(void)
381 {
382 	efi_status_t ret;
383 	int exit_status = EFI_ST_SUCCESS;
384 
385 	if (timer) {
386 		/*
387 		 * Stop timer.
388 		 */
389 		ret = boottime->set_timer(timer, EFI_TIMER_STOP, 0);
390 		if (ret != EFI_SUCCESS) {
391 			efi_st_error("Failed to stop timer");
392 			exit_status = EFI_ST_FAILURE;
393 		}
394 		/*
395 		 * Close timer event.
396 		 */
397 		ret = boottime->close_event(timer);
398 		if (ret != EFI_SUCCESS) {
399 			efi_st_error("Failed to close event");
400 			exit_status = EFI_ST_FAILURE;
401 		}
402 	}
403 	if (net) {
404 		/*
405 		 * Stop network adapter.
406 		 */
407 		ret = net->stop(net);
408 		if (ret != EFI_SUCCESS) {
409 			efi_st_error("Failed to stop network adapter\n");
410 			exit_status = EFI_ST_FAILURE;
411 		}
412 		/*
413 		 * Shut down network adapter.
414 		 */
415 		ret = net->shutdown(net);
416 		if (ret != EFI_SUCCESS) {
417 			efi_st_error("Failed to shut down network adapter\n");
418 			exit_status = EFI_ST_FAILURE;
419 		}
420 	}
421 
422 	return exit_status;
423 }
424 
425 EFI_UNIT_TEST(snp) = {
426 	.name = "simple network protocol",
427 	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
428 	.setup = setup,
429 	.execute = execute,
430 	.teardown = teardown,
431 };
432