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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  EFI device path interface
4  *
5  *  Copyright (c) 2017 Heinrich Schuchardt
6  */
7 
8 #include <common.h>
9 #include <efi_loader.h>
10 
11 #define MAC_OUTPUT_LEN 22
12 #define UNKNOWN_OUTPUT_LEN 23
13 
14 #define MAX_NODE_LEN 512
15 #define MAX_PATH_LEN 1024
16 
17 const efi_guid_t efi_guid_device_path_to_text_protocol =
18 		EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID;
19 
20 /**
21  * efi_str_to_u16() - convert ASCII string to UTF-16
22  *
23  * A u16 buffer is allocated from pool. The ASCII string is copied to the u16
24  * buffer.
25  *
26  * @str:	ASCII string
27  * Return:	UTF-16 string. NULL if out of memory.
28  */
efi_str_to_u16(char * str)29 static u16 *efi_str_to_u16(char *str)
30 {
31 	efi_uintn_t len;
32 	u16 *out, *dst;
33 	efi_status_t ret;
34 
35 	len = sizeof(u16) * (utf8_utf16_strlen(str) + 1);
36 	ret = efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, len, (void **)&out);
37 	if (ret != EFI_SUCCESS)
38 		return NULL;
39 	dst = out;
40 	utf8_utf16_strcpy(&dst, str);
41 	return out;
42 }
43 
dp_unknown(char * s,struct efi_device_path * dp)44 static char *dp_unknown(char *s, struct efi_device_path *dp)
45 {
46 	s += sprintf(s, "UNKNOWN(%04x,%04x)", dp->type, dp->sub_type);
47 	return s;
48 }
49 
dp_hardware(char * s,struct efi_device_path * dp)50 static char *dp_hardware(char *s, struct efi_device_path *dp)
51 {
52 	switch (dp->sub_type) {
53 	case DEVICE_PATH_SUB_TYPE_MEMORY: {
54 		struct efi_device_path_memory *mdp =
55 			(struct efi_device_path_memory *)dp;
56 		s += sprintf(s, "MemoryMapped(0x%x,0x%llx,0x%llx)",
57 			     mdp->memory_type,
58 			     mdp->start_address,
59 			     mdp->end_address);
60 		break;
61 	}
62 	case DEVICE_PATH_SUB_TYPE_VENDOR: {
63 		int i, n;
64 		struct efi_device_path_vendor *vdp =
65 			(struct efi_device_path_vendor *)dp;
66 
67 		s += sprintf(s, "VenHw(%pUl", &vdp->guid);
68 		n = (int)vdp->dp.length - sizeof(struct efi_device_path_vendor);
69 		if (n > 0) {
70 			s += sprintf(s, ",");
71 			for (i = 0; i < n; ++i)
72 				s += sprintf(s, "%02x", vdp->vendor_data[i]);
73 		}
74 		s += sprintf(s, ")");
75 		break;
76 	}
77 	default:
78 		s = dp_unknown(s, dp);
79 		break;
80 	}
81 	return s;
82 }
83 
dp_acpi(char * s,struct efi_device_path * dp)84 static char *dp_acpi(char *s, struct efi_device_path *dp)
85 {
86 	switch (dp->sub_type) {
87 	case DEVICE_PATH_SUB_TYPE_ACPI_DEVICE: {
88 		struct efi_device_path_acpi_path *adp =
89 			(struct efi_device_path_acpi_path *)dp;
90 
91 		s += sprintf(s, "Acpi(PNP%04X,%d)", EISA_PNP_NUM(adp->hid),
92 			     adp->uid);
93 		break;
94 	}
95 	default:
96 		s = dp_unknown(s, dp);
97 		break;
98 	}
99 	return s;
100 }
101 
dp_msging(char * s,struct efi_device_path * dp)102 static char *dp_msging(char *s, struct efi_device_path *dp)
103 {
104 	switch (dp->sub_type) {
105 	case DEVICE_PATH_SUB_TYPE_MSG_ATAPI: {
106 		struct efi_device_path_atapi *ide =
107 			(struct efi_device_path_atapi *)dp;
108 		s += sprintf(s, "Ata(%d,%d,%d)", ide->primary_secondary,
109 			     ide->slave_master, ide->logical_unit_number);
110 		break;
111 	}
112 	case DEVICE_PATH_SUB_TYPE_MSG_SCSI: {
113 		struct efi_device_path_scsi *ide =
114 			(struct efi_device_path_scsi *)dp;
115 		s += sprintf(s, "Scsi(%u,%u)", ide->target_id,
116 			     ide->logical_unit_number);
117 		break;
118 	}
119 	case DEVICE_PATH_SUB_TYPE_MSG_USB: {
120 		struct efi_device_path_usb *udp =
121 			(struct efi_device_path_usb *)dp;
122 		s += sprintf(s, "USB(0x%x,0x%x)", udp->parent_port_number,
123 			     udp->usb_interface);
124 		break;
125 	}
126 	case DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR: {
127 		int i, n = sizeof(struct efi_mac_addr);
128 		struct efi_device_path_mac_addr *mdp =
129 			(struct efi_device_path_mac_addr *)dp;
130 
131 		if (mdp->if_type <= 1)
132 			n = 6;
133 		s += sprintf(s, "MAC(");
134 		for (i = 0; i < n; ++i)
135 			s += sprintf(s, "%02x", mdp->mac.addr[i]);
136 		s += sprintf(s, ",%u)", mdp->if_type);
137 
138 		break;
139 	}
140 	case DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS: {
141 		struct efi_device_path_usb_class *ucdp =
142 			(struct efi_device_path_usb_class *)dp;
143 
144 		s += sprintf(s, "UsbClass(0x%x,0x%x,0x%x,0x%x,0x%x)",
145 			ucdp->vendor_id, ucdp->product_id,
146 			ucdp->device_class, ucdp->device_subclass,
147 			ucdp->device_protocol);
148 
149 		break;
150 	}
151 	case DEVICE_PATH_SUB_TYPE_MSG_NVME: {
152 		struct efi_device_path_nvme *ndp =
153 			(struct efi_device_path_nvme *)dp;
154 		u32 ns_id;
155 		int i;
156 
157 		memcpy(&ns_id, &ndp->ns_id, sizeof(ns_id));
158 		s += sprintf(s, "NVMe(0x%x,", ns_id);
159 		for (i = 0; i < sizeof(ndp->eui64); ++i)
160 			s += sprintf(s, "%s%02x", i ? "-" : "",
161 				     ndp->eui64[i]);
162 		s += sprintf(s, ")");
163 
164 		break;
165 	}
166 	case DEVICE_PATH_SUB_TYPE_MSG_SD:
167 	case DEVICE_PATH_SUB_TYPE_MSG_MMC: {
168 		const char *typename =
169 			(dp->sub_type == DEVICE_PATH_SUB_TYPE_MSG_SD) ?
170 					"SD" : "eMMC";
171 		struct efi_device_path_sd_mmc_path *sddp =
172 			(struct efi_device_path_sd_mmc_path *)dp;
173 		s += sprintf(s, "%s(%u)", typename, sddp->slot_number);
174 		break;
175 	}
176 	default:
177 		s = dp_unknown(s, dp);
178 		break;
179 	}
180 	return s;
181 }
182 
183 /*
184  * Convert a media device path node to text.
185  *
186  * @s		output buffer
187  * @dp		device path node
188  * @return	next unused buffer address
189  */
dp_media(char * s,struct efi_device_path * dp)190 static char *dp_media(char *s, struct efi_device_path *dp)
191 {
192 	switch (dp->sub_type) {
193 	case DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH: {
194 		struct efi_device_path_hard_drive_path *hddp =
195 			(struct efi_device_path_hard_drive_path *)dp;
196 		void *sig = hddp->partition_signature;
197 		u64 start;
198 		u64 end;
199 
200 		/* Copy from packed structure to aligned memory */
201 		memcpy(&start, &hddp->partition_start, sizeof(start));
202 		memcpy(&end, &hddp->partition_end, sizeof(end));
203 
204 		switch (hddp->signature_type) {
205 		case SIG_TYPE_MBR: {
206 			u32 signature;
207 
208 			memcpy(&signature, sig, sizeof(signature));
209 			s += sprintf(
210 				s, "HD(%d,MBR,0x%08x,0x%llx,0x%llx)",
211 				hddp->partition_number, signature, start, end);
212 			break;
213 			}
214 		case SIG_TYPE_GUID:
215 			s += sprintf(
216 				s, "HD(%d,GPT,%pUl,0x%llx,0x%llx)",
217 				hddp->partition_number, sig, start, end);
218 			break;
219 		default:
220 			s += sprintf(
221 				s, "HD(%d,0x%02x,0,0x%llx,0x%llx)",
222 				hddp->partition_number, hddp->partmap_type,
223 				start, end);
224 			break;
225 		}
226 
227 		break;
228 	}
229 	case DEVICE_PATH_SUB_TYPE_CDROM_PATH: {
230 		struct efi_device_path_cdrom_path *cddp =
231 			(struct efi_device_path_cdrom_path *)dp;
232 		s += sprintf(s, "CDROM(%u,0x%llx,0x%llx)", cddp->boot_entry,
233 			     cddp->partition_start, cddp->partition_size);
234 		break;
235 	}
236 	case DEVICE_PATH_SUB_TYPE_FILE_PATH: {
237 		struct efi_device_path_file_path *fp =
238 			(struct efi_device_path_file_path *)dp;
239 		int slen = (dp->length - sizeof(*dp)) / 2;
240 		if (slen > MAX_NODE_LEN - 2)
241 			slen = MAX_NODE_LEN - 2;
242 		s += sprintf(s, "%-.*ls", slen, fp->str);
243 		break;
244 	}
245 	default:
246 		s = dp_unknown(s, dp);
247 		break;
248 	}
249 	return s;
250 }
251 
252 /*
253  * Converts a single node to a char string.
254  *
255  * @buffer		output buffer
256  * @dp			device path or node
257  * @return		end of string
258  */
efi_convert_single_device_node_to_text(char * buffer,struct efi_device_path * dp)259 static char *efi_convert_single_device_node_to_text(
260 		char *buffer,
261 		struct efi_device_path *dp)
262 {
263 	char *str = buffer;
264 
265 	switch (dp->type) {
266 	case DEVICE_PATH_TYPE_HARDWARE_DEVICE:
267 		str = dp_hardware(str, dp);
268 		break;
269 	case DEVICE_PATH_TYPE_ACPI_DEVICE:
270 		str = dp_acpi(str, dp);
271 		break;
272 	case DEVICE_PATH_TYPE_MESSAGING_DEVICE:
273 		str = dp_msging(str, dp);
274 		break;
275 	case DEVICE_PATH_TYPE_MEDIA_DEVICE:
276 		str = dp_media(str, dp);
277 		break;
278 	case DEVICE_PATH_TYPE_END:
279 		break;
280 	default:
281 		str = dp_unknown(str, dp);
282 	}
283 
284 	*str = '\0';
285 	return str;
286 }
287 
288 /*
289  * This function implements the ConvertDeviceNodeToText service of the
290  * EFI_DEVICE_PATH_TO_TEXT_PROTOCOL.
291  * See the Unified Extensible Firmware Interface (UEFI) specification
292  * for details.
293  *
294  * device_node		device node to be converted
295  * display_only		true if the shorter text representation shall be used
296  * allow_shortcuts	true if shortcut forms may be used
297  * @return		text representation of the device path
298  *			NULL if out of memory of device_path is NULL
299  */
efi_convert_device_node_to_text(struct efi_device_path * device_node,bool display_only,bool allow_shortcuts)300 static uint16_t EFIAPI *efi_convert_device_node_to_text(
301 		struct efi_device_path *device_node,
302 		bool display_only,
303 		bool allow_shortcuts)
304 {
305 	char str[MAX_NODE_LEN];
306 	uint16_t *text = NULL;
307 
308 	EFI_ENTRY("%p, %d, %d", device_node, display_only, allow_shortcuts);
309 
310 	if (!device_node)
311 		goto out;
312 	efi_convert_single_device_node_to_text(str, device_node);
313 
314 	text = efi_str_to_u16(str);
315 
316 out:
317 	EFI_EXIT(EFI_SUCCESS);
318 	return text;
319 }
320 
321 /*
322  * This function implements the ConvertDevicePathToText service of the
323  * EFI_DEVICE_PATH_TO_TEXT_PROTOCOL.
324  * See the Unified Extensible Firmware Interface (UEFI) specification
325  * for details.
326  *
327  * device_path		device path to be converted
328  * display_only		true if the shorter text representation shall be used
329  * allow_shortcuts	true if shortcut forms may be used
330  * @return		text representation of the device path
331  *			NULL if out of memory of device_path is NULL
332  */
efi_convert_device_path_to_text(struct efi_device_path * device_path,bool display_only,bool allow_shortcuts)333 static uint16_t EFIAPI *efi_convert_device_path_to_text(
334 		struct efi_device_path *device_path,
335 		bool display_only,
336 		bool allow_shortcuts)
337 {
338 	uint16_t *text = NULL;
339 	char buffer[MAX_PATH_LEN];
340 	char *str = buffer;
341 
342 	EFI_ENTRY("%p, %d, %d", device_path, display_only, allow_shortcuts);
343 
344 	if (!device_path)
345 		goto out;
346 	while (device_path &&
347 	       str + MAX_NODE_LEN < buffer + MAX_PATH_LEN) {
348 		*str++ = '/';
349 		str = efi_convert_single_device_node_to_text(str, device_path);
350 		device_path = efi_dp_next(device_path);
351 	}
352 
353 	text = efi_str_to_u16(buffer);
354 
355 out:
356 	EFI_EXIT(EFI_SUCCESS);
357 	return text;
358 }
359 
360 /* helper for debug prints.. efi_free_pool() the result. */
efi_dp_str(struct efi_device_path * dp)361 uint16_t *efi_dp_str(struct efi_device_path *dp)
362 {
363 	return EFI_CALL(efi_convert_device_path_to_text(dp, true, true));
364 }
365 
366 const struct efi_device_path_to_text_protocol efi_device_path_to_text = {
367 	.convert_device_node_to_text = efi_convert_device_node_to_text,
368 	.convert_device_path_to_text = efi_convert_device_path_to_text,
369 };
370