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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 
efi_str_to_u16(char * str)20 static u16 *efi_str_to_u16(char *str)
21 {
22 	efi_uintn_t len;
23 	u16 *out;
24 	efi_status_t ret;
25 
26 	len = strlen(str) + 1;
27 	ret = efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, len * sizeof(u16),
28 				(void **)&out);
29 	if (ret != EFI_SUCCESS)
30 		return NULL;
31 	ascii2unicode(out, str);
32 	out[len - 1] = 0;
33 	return out;
34 }
35 
dp_unknown(char * s,struct efi_device_path * dp)36 static char *dp_unknown(char *s, struct efi_device_path *dp)
37 {
38 	s += sprintf(s, "UNKNOWN(%04x,%04x)", dp->type, dp->sub_type);
39 	return s;
40 }
41 
dp_hardware(char * s,struct efi_device_path * dp)42 static char *dp_hardware(char *s, struct efi_device_path *dp)
43 {
44 	switch (dp->sub_type) {
45 	case DEVICE_PATH_SUB_TYPE_MEMORY: {
46 		struct efi_device_path_memory *mdp =
47 			(struct efi_device_path_memory *)dp;
48 		s += sprintf(s, "MemoryMapped(0x%x,0x%llx,0x%llx)",
49 			     mdp->memory_type,
50 			     mdp->start_address,
51 			     mdp->end_address);
52 		break;
53 	}
54 	case DEVICE_PATH_SUB_TYPE_VENDOR: {
55 		struct efi_device_path_vendor *vdp =
56 			(struct efi_device_path_vendor *)dp;
57 		s += sprintf(s, "VenHw(%pUl)", &vdp->guid);
58 		break;
59 	}
60 	default:
61 		s = dp_unknown(s, dp);
62 		break;
63 	}
64 	return s;
65 }
66 
dp_acpi(char * s,struct efi_device_path * dp)67 static char *dp_acpi(char *s, struct efi_device_path *dp)
68 {
69 	switch (dp->sub_type) {
70 	case DEVICE_PATH_SUB_TYPE_ACPI_DEVICE: {
71 		struct efi_device_path_acpi_path *adp =
72 			(struct efi_device_path_acpi_path *)dp;
73 		s += sprintf(s, "Acpi(PNP%04x", EISA_PNP_NUM(adp->hid));
74 		if (adp->uid)
75 			s += sprintf(s, ",%d", adp->uid);
76 		s += sprintf(s, ")");
77 		break;
78 	}
79 	default:
80 		s = dp_unknown(s, dp);
81 		break;
82 	}
83 	return s;
84 }
85 
dp_msging(char * s,struct efi_device_path * dp)86 static char *dp_msging(char *s, struct efi_device_path *dp)
87 {
88 	switch (dp->sub_type) {
89 	case DEVICE_PATH_SUB_TYPE_MSG_ATAPI: {
90 		struct efi_device_path_atapi *ide =
91 			(struct efi_device_path_atapi *)dp;
92 		s += sprintf(s, "Ata(%d,%d,%d)", ide->primary_secondary,
93 			     ide->slave_master, ide->logical_unit_number);
94 		break;
95 	}
96 	case DEVICE_PATH_SUB_TYPE_MSG_SCSI: {
97 		struct efi_device_path_scsi *ide =
98 			(struct efi_device_path_scsi *)dp;
99 		s += sprintf(s, "Scsi(%u,%u)", ide->target_id,
100 			     ide->logical_unit_number);
101 		break;
102 	}
103 	case DEVICE_PATH_SUB_TYPE_MSG_USB: {
104 		struct efi_device_path_usb *udp =
105 			(struct efi_device_path_usb *)dp;
106 		s += sprintf(s, "USB(0x%x,0x%x)", udp->parent_port_number,
107 			     udp->usb_interface);
108 		break;
109 	}
110 	case DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR: {
111 		struct efi_device_path_mac_addr *mdp =
112 			(struct efi_device_path_mac_addr *)dp;
113 
114 		if (mdp->if_type != 0 && mdp->if_type != 1)
115 			break;
116 
117 		s += sprintf(s, "MAC(%02x%02x%02x%02x%02x%02x,0x%1x)",
118 			mdp->mac.addr[0], mdp->mac.addr[1],
119 			mdp->mac.addr[2], mdp->mac.addr[3],
120 			mdp->mac.addr[4], mdp->mac.addr[5],
121 			mdp->if_type);
122 
123 		break;
124 	}
125 	case DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS: {
126 		struct efi_device_path_usb_class *ucdp =
127 			(struct efi_device_path_usb_class *)dp;
128 
129 		s += sprintf(s, "USBClass(%x,%x,%x,%x,%x)",
130 			ucdp->vendor_id, ucdp->product_id,
131 			ucdp->device_class, ucdp->device_subclass,
132 			ucdp->device_protocol);
133 
134 		break;
135 	}
136 	case DEVICE_PATH_SUB_TYPE_MSG_SD:
137 	case DEVICE_PATH_SUB_TYPE_MSG_MMC: {
138 		const char *typename =
139 			(dp->sub_type == DEVICE_PATH_SUB_TYPE_MSG_SD) ?
140 					"SD" : "eMMC";
141 		struct efi_device_path_sd_mmc_path *sddp =
142 			(struct efi_device_path_sd_mmc_path *)dp;
143 		s += sprintf(s, "%s(%u)", typename, sddp->slot_number);
144 		break;
145 	}
146 	default:
147 		s = dp_unknown(s, dp);
148 		break;
149 	}
150 	return s;
151 }
152 
153 /*
154  * Convert a media device path node to text.
155  *
156  * @s		output buffer
157  * @dp		device path node
158  * @return	next unused buffer address
159  */
dp_media(char * s,struct efi_device_path * dp)160 static char *dp_media(char *s, struct efi_device_path *dp)
161 {
162 	switch (dp->sub_type) {
163 	case DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH: {
164 		struct efi_device_path_hard_drive_path *hddp =
165 			(struct efi_device_path_hard_drive_path *)dp;
166 		void *sig = hddp->partition_signature;
167 		u64 start;
168 		u64 end;
169 
170 		/* Copy from packed structure to aligned memory */
171 		memcpy(&start, &hddp->partition_start, sizeof(start));
172 		memcpy(&end, &hddp->partition_end, sizeof(end));
173 
174 		switch (hddp->signature_type) {
175 		case SIG_TYPE_MBR: {
176 			u32 signature;
177 
178 			memcpy(&signature, sig, sizeof(signature));
179 			s += sprintf(
180 				s, "HD(%d,MBR,0x%08x,0x%llx,0x%llx)",
181 				hddp->partition_number, signature, start, end);
182 			break;
183 			}
184 		case SIG_TYPE_GUID:
185 			s += sprintf(
186 				s, "HD(%d,GPT,%pUl,0x%llx,0x%llx)",
187 				hddp->partition_number, sig, start, end);
188 			break;
189 		default:
190 			s += sprintf(
191 				s, "HD(%d,0x%02x,0,0x%llx,0x%llx)",
192 				hddp->partition_number, hddp->partmap_type,
193 				start, end);
194 			break;
195 		}
196 
197 		break;
198 	}
199 	case DEVICE_PATH_SUB_TYPE_CDROM_PATH: {
200 		struct efi_device_path_cdrom_path *cddp =
201 			(struct efi_device_path_cdrom_path *)dp;
202 		s += sprintf(s, "CDROM(0x%x)", cddp->boot_entry);
203 		break;
204 	}
205 	case DEVICE_PATH_SUB_TYPE_FILE_PATH: {
206 		struct efi_device_path_file_path *fp =
207 			(struct efi_device_path_file_path *)dp;
208 		int slen = (dp->length - sizeof(*dp)) / 2;
209 		if (slen > MAX_NODE_LEN - 2)
210 			slen = MAX_NODE_LEN - 2;
211 		s += sprintf(s, "%-.*ls", slen, fp->str);
212 		break;
213 	}
214 	default:
215 		s = dp_unknown(s, dp);
216 		break;
217 	}
218 	return s;
219 }
220 
221 /*
222  * Converts a single node to a char string.
223  *
224  * @buffer		output buffer
225  * @dp			device path or node
226  * @return		end of string
227  */
efi_convert_single_device_node_to_text(char * buffer,struct efi_device_path * dp)228 static char *efi_convert_single_device_node_to_text(
229 		char *buffer,
230 		struct efi_device_path *dp)
231 {
232 	char *str = buffer;
233 
234 	switch (dp->type) {
235 	case DEVICE_PATH_TYPE_HARDWARE_DEVICE:
236 		str = dp_hardware(str, dp);
237 		break;
238 	case DEVICE_PATH_TYPE_ACPI_DEVICE:
239 		str = dp_acpi(str, dp);
240 		break;
241 	case DEVICE_PATH_TYPE_MESSAGING_DEVICE:
242 		str = dp_msging(str, dp);
243 		break;
244 	case DEVICE_PATH_TYPE_MEDIA_DEVICE:
245 		str = dp_media(str, dp);
246 		break;
247 	case DEVICE_PATH_TYPE_END:
248 		break;
249 	default:
250 		str = dp_unknown(str, dp);
251 	}
252 
253 	*str = '\0';
254 	return str;
255 }
256 
257 /*
258  * This function implements the ConvertDeviceNodeToText service of the
259  * EFI_DEVICE_PATH_TO_TEXT_PROTOCOL.
260  * See the Unified Extensible Firmware Interface (UEFI) specification
261  * for details.
262  *
263  * device_node		device node to be converted
264  * display_only		true if the shorter text represenation shall be used
265  * allow_shortcuts	true if shortcut forms may be used
266  * @return		text represenation of the device path
267  *			NULL if out of memory of device_path is NULL
268  */
efi_convert_device_node_to_text(struct efi_device_path * device_node,bool display_only,bool allow_shortcuts)269 static uint16_t EFIAPI *efi_convert_device_node_to_text(
270 		struct efi_device_path *device_node,
271 		bool display_only,
272 		bool allow_shortcuts)
273 {
274 	char str[MAX_NODE_LEN];
275 	uint16_t *text = NULL;
276 
277 	EFI_ENTRY("%p, %d, %d", device_node, display_only, allow_shortcuts);
278 
279 	if (!device_node)
280 		goto out;
281 	efi_convert_single_device_node_to_text(str, device_node);
282 
283 	text = efi_str_to_u16(str);
284 
285 out:
286 	EFI_EXIT(EFI_SUCCESS);
287 	return text;
288 }
289 
290 /*
291  * This function implements the ConvertDevicePathToText service of the
292  * EFI_DEVICE_PATH_TO_TEXT_PROTOCOL.
293  * See the Unified Extensible Firmware Interface (UEFI) specification
294  * for details.
295  *
296  * device_path		device path to be converted
297  * display_only		true if the shorter text represenation shall be used
298  * allow_shortcuts	true if shortcut forms may be used
299  * @return		text represenation of the device path
300  *			NULL if out of memory of device_path is NULL
301  */
efi_convert_device_path_to_text(struct efi_device_path * device_path,bool display_only,bool allow_shortcuts)302 static uint16_t EFIAPI *efi_convert_device_path_to_text(
303 		struct efi_device_path *device_path,
304 		bool display_only,
305 		bool allow_shortcuts)
306 {
307 	uint16_t *text = NULL;
308 	char buffer[MAX_PATH_LEN];
309 	char *str = buffer;
310 
311 	EFI_ENTRY("%p, %d, %d", device_path, display_only, allow_shortcuts);
312 
313 	if (!device_path)
314 		goto out;
315 	while (device_path &&
316 	       str + MAX_NODE_LEN < buffer + MAX_PATH_LEN) {
317 		*str++ = '/';
318 		str = efi_convert_single_device_node_to_text(str, device_path);
319 		device_path = efi_dp_next(device_path);
320 	}
321 
322 	text = efi_str_to_u16(buffer);
323 
324 out:
325 	EFI_EXIT(EFI_SUCCESS);
326 	return text;
327 }
328 
329 /* helper for debug prints.. efi_free_pool() the result. */
efi_dp_str(struct efi_device_path * dp)330 uint16_t *efi_dp_str(struct efi_device_path *dp)
331 {
332 	return EFI_CALL(efi_convert_device_path_to_text(dp, true, true));
333 }
334 
335 const struct efi_device_path_to_text_protocol efi_device_path_to_text = {
336 	.convert_device_node_to_text = efi_convert_device_node_to_text,
337 	.convert_device_path_to_text = efi_convert_device_path_to_text,
338 };
339