1 /*
2  *  EFI device path interface
3  *
4  *  Copyright (c) 2017 Heinrich Schuchardt
5  *
6  *  SPDX-License-Identifier:     GPL-2.0+
7  */
8 
9 #include <common.h>
10 #include <efi_loader.h>
11 
12 #define MAC_OUTPUT_LEN 22
13 #define UNKNOWN_OUTPUT_LEN 23
14 
15 #define MAX_NODE_LEN 512
16 #define MAX_PATH_LEN 1024
17 
18 const efi_guid_t efi_guid_device_path_to_text_protocol =
19 		EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID;
20 
21 static u16 *efi_str_to_u16(char *str)
22 {
23 	efi_uintn_t len;
24 	u16 *out;
25 	efi_status_t ret;
26 
27 	len = strlen(str) + 1;
28 	ret = efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, len * sizeof(u16),
29 				(void **)&out);
30 	if (ret != EFI_SUCCESS)
31 		return NULL;
32 	ascii2unicode(out, str);
33 	out[len - 1] = 0;
34 	return out;
35 }
36 
37 static char *dp_unknown(char *s, struct efi_device_path *dp)
38 {
39 	s += sprintf(s, "UNKNOWN(%04x,%04x)", dp->type, dp->sub_type);
40 	return s;
41 }
42 
43 static char *dp_hardware(char *s, struct efi_device_path *dp)
44 {
45 	switch (dp->sub_type) {
46 	case DEVICE_PATH_SUB_TYPE_MEMORY: {
47 		struct efi_device_path_memory *mdp =
48 			(struct efi_device_path_memory *)dp;
49 		s += sprintf(s, "MemoryMapped(0x%x,0x%llx,0x%llx)",
50 			     mdp->memory_type,
51 			     mdp->start_address,
52 			     mdp->end_address);
53 		break;
54 	}
55 	case DEVICE_PATH_SUB_TYPE_VENDOR: {
56 		struct efi_device_path_vendor *vdp =
57 			(struct efi_device_path_vendor *)dp;
58 		s += sprintf(s, "VenHw(%pUl)", &vdp->guid);
59 		break;
60 	}
61 	default:
62 		s = dp_unknown(s, dp);
63 		break;
64 	}
65 	return s;
66 }
67 
68 static char *dp_acpi(char *s, struct efi_device_path *dp)
69 {
70 	switch (dp->sub_type) {
71 	case DEVICE_PATH_SUB_TYPE_ACPI_DEVICE: {
72 		struct efi_device_path_acpi_path *adp =
73 			(struct efi_device_path_acpi_path *)dp;
74 		s += sprintf(s, "Acpi(PNP%04x", EISA_PNP_NUM(adp->hid));
75 		if (adp->uid)
76 			s += sprintf(s, ",%d", adp->uid);
77 		s += sprintf(s, ")");
78 		break;
79 	}
80 	default:
81 		s = dp_unknown(s, dp);
82 		break;
83 	}
84 	return s;
85 }
86 
87 static char *dp_msging(char *s, struct efi_device_path *dp)
88 {
89 	switch (dp->sub_type) {
90 	case DEVICE_PATH_SUB_TYPE_MSG_USB: {
91 		struct efi_device_path_usb *udp =
92 			(struct efi_device_path_usb *)dp;
93 		s += sprintf(s, "USB(0x%x,0x%x)", udp->parent_port_number,
94 			     udp->usb_interface);
95 		break;
96 	}
97 	case DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR: {
98 		struct efi_device_path_mac_addr *mdp =
99 			(struct efi_device_path_mac_addr *)dp;
100 
101 		if (mdp->if_type != 0 && mdp->if_type != 1)
102 			break;
103 
104 		s += sprintf(s, "MAC(%02x%02x%02x%02x%02x%02x,0x%1x)",
105 			mdp->mac.addr[0], mdp->mac.addr[1],
106 			mdp->mac.addr[2], mdp->mac.addr[3],
107 			mdp->mac.addr[4], mdp->mac.addr[5],
108 			mdp->if_type);
109 
110 		break;
111 	}
112 	case DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS: {
113 		struct efi_device_path_usb_class *ucdp =
114 			(struct efi_device_path_usb_class *)dp;
115 
116 		s += sprintf(s, "USBClass(%x,%x,%x,%x,%x)",
117 			ucdp->vendor_id, ucdp->product_id,
118 			ucdp->device_class, ucdp->device_subclass,
119 			ucdp->device_protocol);
120 
121 		break;
122 	}
123 	case DEVICE_PATH_SUB_TYPE_MSG_SD:
124 	case DEVICE_PATH_SUB_TYPE_MSG_MMC: {
125 		const char *typename =
126 			(dp->sub_type == DEVICE_PATH_SUB_TYPE_MSG_SD) ?
127 					"SD" : "eMMC";
128 		struct efi_device_path_sd_mmc_path *sddp =
129 			(struct efi_device_path_sd_mmc_path *)dp;
130 		s += sprintf(s, "%s(%u)", typename, sddp->slot_number);
131 		break;
132 	}
133 	default:
134 		s = dp_unknown(s, dp);
135 		break;
136 	}
137 	return s;
138 }
139 
140 /*
141  * Convert a media device path node to text.
142  *
143  * @s		output buffer
144  * @dp		device path node
145  * @return	next unused buffer address
146  */
147 static char *dp_media(char *s, struct efi_device_path *dp)
148 {
149 	switch (dp->sub_type) {
150 	case DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH: {
151 		struct efi_device_path_hard_drive_path *hddp =
152 			(struct efi_device_path_hard_drive_path *)dp;
153 		void *sig = hddp->partition_signature;
154 		u64 start;
155 		u64 end;
156 
157 		/* Copy from packed structure to aligned memory */
158 		memcpy(&start, &hddp->partition_start, sizeof(start));
159 		memcpy(&end, &hddp->partition_end, sizeof(end));
160 
161 		switch (hddp->signature_type) {
162 		case SIG_TYPE_MBR: {
163 			u32 signature;
164 
165 			memcpy(&signature, sig, sizeof(signature));
166 			s += sprintf(
167 				s, "HD(%d,MBR,0x%08x,0x%llx,0x%llx)",
168 				hddp->partition_number, signature, start, end);
169 			break;
170 			}
171 		case SIG_TYPE_GUID:
172 			s += sprintf(
173 				s, "HD(%d,GPT,%pUl,0x%llx,0x%llx)",
174 				hddp->partition_number, sig, start, end);
175 			break;
176 		default:
177 			s += sprintf(
178 				s, "HD(%d,0x%02x,0,0x%llx,0x%llx)",
179 				hddp->partition_number, hddp->partmap_type,
180 				start, end);
181 			break;
182 		}
183 
184 		break;
185 	}
186 	case DEVICE_PATH_SUB_TYPE_CDROM_PATH: {
187 		struct efi_device_path_cdrom_path *cddp =
188 			(struct efi_device_path_cdrom_path *)dp;
189 		s += sprintf(s, "CDROM(0x%x)", cddp->boot_entry);
190 		break;
191 	}
192 	case DEVICE_PATH_SUB_TYPE_FILE_PATH: {
193 		struct efi_device_path_file_path *fp =
194 			(struct efi_device_path_file_path *)dp;
195 		int slen = (dp->length - sizeof(*dp)) / 2;
196 		if (slen > MAX_NODE_LEN - 2)
197 			slen = MAX_NODE_LEN - 2;
198 		s += sprintf(s, "%-.*ls", slen, fp->str);
199 		break;
200 	}
201 	default:
202 		s = dp_unknown(s, dp);
203 		break;
204 	}
205 	return s;
206 }
207 
208 /*
209  * Converts a single node to a char string.
210  *
211  * @buffer		output buffer
212  * @dp			device path or node
213  * @return		end of string
214  */
215 static char *efi_convert_single_device_node_to_text(
216 		char *buffer,
217 		struct efi_device_path *dp)
218 {
219 	char *str = buffer;
220 
221 	switch (dp->type) {
222 	case DEVICE_PATH_TYPE_HARDWARE_DEVICE:
223 		str = dp_hardware(str, dp);
224 		break;
225 	case DEVICE_PATH_TYPE_ACPI_DEVICE:
226 		str = dp_acpi(str, dp);
227 		break;
228 	case DEVICE_PATH_TYPE_MESSAGING_DEVICE:
229 		str = dp_msging(str, dp);
230 		break;
231 	case DEVICE_PATH_TYPE_MEDIA_DEVICE:
232 		str = dp_media(str, dp);
233 		break;
234 	default:
235 		str = dp_unknown(str, dp);
236 	}
237 
238 	*str = '\0';
239 	return str;
240 }
241 
242 /*
243  * This function implements the ConvertDeviceNodeToText service of the
244  * EFI_DEVICE_PATH_TO_TEXT_PROTOCOL.
245  * See the Unified Extensible Firmware Interface (UEFI) specification
246  * for details.
247  *
248  * device_node		device node to be converted
249  * display_only		true if the shorter text represenation shall be used
250  * allow_shortcuts	true if shortcut forms may be used
251  * @return		text represenation of the device path
252  *			NULL if out of memory of device_path is NULL
253  */
254 static uint16_t EFIAPI *efi_convert_device_node_to_text(
255 		struct efi_device_path *device_node,
256 		bool display_only,
257 		bool allow_shortcuts)
258 {
259 	char str[MAX_NODE_LEN];
260 	uint16_t *text = NULL;
261 
262 	EFI_ENTRY("%p, %d, %d", device_node, display_only, allow_shortcuts);
263 
264 	if (!device_node)
265 		goto out;
266 	efi_convert_single_device_node_to_text(str, device_node);
267 
268 	text = efi_str_to_u16(str);
269 
270 out:
271 	EFI_EXIT(EFI_SUCCESS);
272 	return text;
273 }
274 
275 /*
276  * This function implements the ConvertDevicePathToText service of the
277  * EFI_DEVICE_PATH_TO_TEXT_PROTOCOL.
278  * See the Unified Extensible Firmware Interface (UEFI) specification
279  * for details.
280  *
281  * device_path		device path to be converted
282  * display_only		true if the shorter text represenation shall be used
283  * allow_shortcuts	true if shortcut forms may be used
284  * @return		text represenation of the device path
285  *			NULL if out of memory of device_path is NULL
286  */
287 static uint16_t EFIAPI *efi_convert_device_path_to_text(
288 		struct efi_device_path *device_path,
289 		bool display_only,
290 		bool allow_shortcuts)
291 {
292 	uint16_t *text = NULL;
293 	char buffer[MAX_PATH_LEN];
294 	char *str = buffer;
295 
296 	EFI_ENTRY("%p, %d, %d", device_path, display_only, allow_shortcuts);
297 
298 	if (!device_path)
299 		goto out;
300 	while (device_path &&
301 	       str + MAX_NODE_LEN < buffer + MAX_PATH_LEN) {
302 		*str++ = '/';
303 		str = efi_convert_single_device_node_to_text(str, device_path);
304 		device_path = efi_dp_next(device_path);
305 	}
306 
307 	text = efi_str_to_u16(buffer);
308 
309 out:
310 	EFI_EXIT(EFI_SUCCESS);
311 	return text;
312 }
313 
314 /* helper for debug prints.. efi_free_pool() the result. */
315 uint16_t *efi_dp_str(struct efi_device_path *dp)
316 {
317 	return EFI_CALL(efi_convert_device_path_to_text(dp, true, true));
318 }
319 
320 const struct efi_device_path_to_text_protocol efi_device_path_to_text = {
321 	.convert_device_node_to_text = efi_convert_device_node_to_text,
322 	.convert_device_path_to_text = efi_convert_device_path_to_text,
323 };
324