xref: /linux/tools/hv/hv_fcopy_uio_daemon.c (revision da5b2ad1c2f18834cb1ce429e2e5a5cf5cbdf21b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * An implementation of host to guest copy functionality for Linux.
4  *
5  * Copyright (C) 2023, Microsoft, Inc.
6  *
7  * Author : K. Y. Srinivasan <kys@microsoft.com>
8  * Author : Saurabh Sengar <ssengar@microsoft.com>
9  *
10  */
11 
12 #include <dirent.h>
13 #include <errno.h>
14 #include <fcntl.h>
15 #include <getopt.h>
16 #include <locale.h>
17 #include <stdbool.h>
18 #include <stddef.h>
19 #include <stdint.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <syslog.h>
24 #include <unistd.h>
25 #include <wchar.h>
26 #include <sys/stat.h>
27 #include <linux/hyperv.h>
28 #include <linux/limits.h>
29 #include "vmbus_bufring.h"
30 
31 #define ICMSGTYPE_NEGOTIATE	0
32 #define ICMSGTYPE_FCOPY		7
33 
34 #define WIN8_SRV_MAJOR		1
35 #define WIN8_SRV_MINOR		1
36 #define WIN8_SRV_VERSION	(WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
37 
38 #define MAX_FOLDER_NAME		15
39 #define MAX_PATH_LEN		15
40 #define FCOPY_UIO		"/sys/bus/vmbus/devices/eb765408-105f-49b6-b4aa-c123b64d17d4/uio"
41 
42 #define FCOPY_VER_COUNT		1
43 static const int fcopy_versions[] = {
44 	WIN8_SRV_VERSION
45 };
46 
47 #define FW_VER_COUNT		1
48 static const int fw_versions[] = {
49 	UTIL_FW_VERSION
50 };
51 
52 #define HV_RING_SIZE		0x4000 /* 16KB ring buffer size */
53 
54 unsigned char desc[HV_RING_SIZE];
55 
56 static int target_fd;
57 static char target_fname[PATH_MAX];
58 static unsigned long long filesize;
59 
60 static int hv_fcopy_create_file(char *file_name, char *path_name, __u32 flags)
61 {
62 	int error = HV_E_FAIL;
63 	char *q, *p;
64 
65 	filesize = 0;
66 	p = path_name;
67 	snprintf(target_fname, sizeof(target_fname), "%s/%s",
68 		 path_name, file_name);
69 
70 	/*
71 	 * Check to see if the path is already in place; if not,
72 	 * create if required.
73 	 */
74 	while ((q = strchr(p, '/')) != NULL) {
75 		if (q == p) {
76 			p++;
77 			continue;
78 		}
79 		*q = '\0';
80 		if (access(path_name, F_OK)) {
81 			if (flags & CREATE_PATH) {
82 				if (mkdir(path_name, 0755)) {
83 					syslog(LOG_ERR, "Failed to create %s",
84 					       path_name);
85 					goto done;
86 				}
87 			} else {
88 				syslog(LOG_ERR, "Invalid path: %s", path_name);
89 				goto done;
90 			}
91 		}
92 		p = q + 1;
93 		*q = '/';
94 	}
95 
96 	if (!access(target_fname, F_OK)) {
97 		syslog(LOG_INFO, "File: %s exists", target_fname);
98 		if (!(flags & OVER_WRITE)) {
99 			error = HV_ERROR_ALREADY_EXISTS;
100 			goto done;
101 		}
102 	}
103 
104 	target_fd = open(target_fname,
105 			 O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0744);
106 	if (target_fd == -1) {
107 		syslog(LOG_INFO, "Open Failed: %s", strerror(errno));
108 		goto done;
109 	}
110 
111 	error = 0;
112 done:
113 	if (error)
114 		target_fname[0] = '\0';
115 	return error;
116 }
117 
118 /* copy the data into the file */
119 static int hv_copy_data(struct hv_do_fcopy *cpmsg)
120 {
121 	ssize_t len;
122 	int ret = 0;
123 
124 	len = pwrite(target_fd, cpmsg->data, cpmsg->size, cpmsg->offset);
125 
126 	filesize += cpmsg->size;
127 	if (len != cpmsg->size) {
128 		switch (errno) {
129 		case ENOSPC:
130 			ret = HV_ERROR_DISK_FULL;
131 			break;
132 		default:
133 			ret = HV_E_FAIL;
134 			break;
135 		}
136 		syslog(LOG_ERR, "pwrite failed to write %llu bytes: %ld (%s)",
137 		       filesize, (long)len, strerror(errno));
138 	}
139 
140 	return ret;
141 }
142 
143 static int hv_copy_finished(void)
144 {
145 	close(target_fd);
146 	target_fname[0] = '\0';
147 
148 	return 0;
149 }
150 
151 static void print_usage(char *argv[])
152 {
153 	fprintf(stderr, "Usage: %s [options]\n"
154 		"Options are:\n"
155 		"  -n, --no-daemon        stay in foreground, don't daemonize\n"
156 		"  -h, --help             print this help\n", argv[0]);
157 }
158 
159 static bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, unsigned char *buf,
160 				      unsigned int buflen, const int *fw_version, int fw_vercnt,
161 				const int *srv_version, int srv_vercnt,
162 				int *nego_fw_version, int *nego_srv_version)
163 {
164 	int icframe_major, icframe_minor;
165 	int icmsg_major, icmsg_minor;
166 	int fw_major, fw_minor;
167 	int srv_major, srv_minor;
168 	int i, j;
169 	bool found_match = false;
170 	struct icmsg_negotiate *negop;
171 
172 	/* Check that there's enough space for icframe_vercnt, icmsg_vercnt */
173 	if (buflen < ICMSG_HDR + offsetof(struct icmsg_negotiate, reserved)) {
174 		syslog(LOG_ERR, "Invalid icmsg negotiate");
175 		return false;
176 	}
177 
178 	icmsghdrp->icmsgsize = 0x10;
179 	negop = (struct icmsg_negotiate *)&buf[ICMSG_HDR];
180 
181 	icframe_major = negop->icframe_vercnt;
182 	icframe_minor = 0;
183 
184 	icmsg_major = negop->icmsg_vercnt;
185 	icmsg_minor = 0;
186 
187 	/* Validate negop packet */
188 	if (icframe_major > IC_VERSION_NEGOTIATION_MAX_VER_COUNT ||
189 	    icmsg_major > IC_VERSION_NEGOTIATION_MAX_VER_COUNT ||
190 	    ICMSG_NEGOTIATE_PKT_SIZE(icframe_major, icmsg_major) > buflen) {
191 		syslog(LOG_ERR, "Invalid icmsg negotiate - icframe_major: %u, icmsg_major: %u\n",
192 		       icframe_major, icmsg_major);
193 		goto fw_error;
194 	}
195 
196 	/*
197 	 * Select the framework version number we will
198 	 * support.
199 	 */
200 
201 	for (i = 0; i < fw_vercnt; i++) {
202 		fw_major = (fw_version[i] >> 16);
203 		fw_minor = (fw_version[i] & 0xFFFF);
204 
205 		for (j = 0; j < negop->icframe_vercnt; j++) {
206 			if (negop->icversion_data[j].major == fw_major &&
207 			    negop->icversion_data[j].minor == fw_minor) {
208 				icframe_major = negop->icversion_data[j].major;
209 				icframe_minor = negop->icversion_data[j].minor;
210 				found_match = true;
211 				break;
212 			}
213 		}
214 
215 		if (found_match)
216 			break;
217 	}
218 
219 	if (!found_match)
220 		goto fw_error;
221 
222 	found_match = false;
223 
224 	for (i = 0; i < srv_vercnt; i++) {
225 		srv_major = (srv_version[i] >> 16);
226 		srv_minor = (srv_version[i] & 0xFFFF);
227 
228 		for (j = negop->icframe_vercnt;
229 			(j < negop->icframe_vercnt + negop->icmsg_vercnt);
230 			j++) {
231 			if (negop->icversion_data[j].major == srv_major &&
232 			    negop->icversion_data[j].minor == srv_minor) {
233 				icmsg_major = negop->icversion_data[j].major;
234 				icmsg_minor = negop->icversion_data[j].minor;
235 				found_match = true;
236 				break;
237 			}
238 		}
239 
240 		if (found_match)
241 			break;
242 	}
243 
244 	/*
245 	 * Respond with the framework and service
246 	 * version numbers we can support.
247 	 */
248 fw_error:
249 	if (!found_match) {
250 		negop->icframe_vercnt = 0;
251 		negop->icmsg_vercnt = 0;
252 	} else {
253 		negop->icframe_vercnt = 1;
254 		negop->icmsg_vercnt = 1;
255 	}
256 
257 	if (nego_fw_version)
258 		*nego_fw_version = (icframe_major << 16) | icframe_minor;
259 
260 	if (nego_srv_version)
261 		*nego_srv_version = (icmsg_major << 16) | icmsg_minor;
262 
263 	negop->icversion_data[0].major = icframe_major;
264 	negop->icversion_data[0].minor = icframe_minor;
265 	negop->icversion_data[1].major = icmsg_major;
266 	negop->icversion_data[1].minor = icmsg_minor;
267 
268 	return found_match;
269 }
270 
271 static void wcstoutf8(char *dest, const __u16 *src, size_t dest_size)
272 {
273 	size_t len = 0;
274 
275 	while (len < dest_size) {
276 		if (src[len] < 0x80)
277 			dest[len++] = (char)(*src++);
278 		else
279 			dest[len++] = 'X';
280 	}
281 
282 	dest[len] = '\0';
283 }
284 
285 static int hv_fcopy_start(struct hv_start_fcopy *smsg_in)
286 {
287 	setlocale(LC_ALL, "en_US.utf8");
288 	size_t file_size, path_size;
289 	char *file_name, *path_name;
290 	char *in_file_name = (char *)smsg_in->file_name;
291 	char *in_path_name = (char *)smsg_in->path_name;
292 
293 	file_size = wcstombs(NULL, (const wchar_t *restrict)in_file_name, 0) + 1;
294 	path_size = wcstombs(NULL, (const wchar_t *restrict)in_path_name, 0) + 1;
295 
296 	file_name = (char *)malloc(file_size * sizeof(char));
297 	path_name = (char *)malloc(path_size * sizeof(char));
298 
299 	wcstoutf8(file_name, (__u16 *)in_file_name, file_size);
300 	wcstoutf8(path_name, (__u16 *)in_path_name, path_size);
301 
302 	return hv_fcopy_create_file(file_name, path_name, smsg_in->copy_flags);
303 }
304 
305 static int hv_fcopy_send_data(struct hv_fcopy_hdr *fcopy_msg, int recvlen)
306 {
307 	int operation = fcopy_msg->operation;
308 
309 	/*
310 	 * The  strings sent from the host are encoded in
311 	 * utf16; convert it to utf8 strings.
312 	 * The host assures us that the utf16 strings will not exceed
313 	 * the max lengths specified. We will however, reserve room
314 	 * for the string terminating character - in the utf16s_utf8s()
315 	 * function we limit the size of the buffer where the converted
316 	 * string is placed to W_MAX_PATH -1 to guarantee
317 	 * that the strings can be properly terminated!
318 	 */
319 
320 	switch (operation) {
321 	case START_FILE_COPY:
322 		return hv_fcopy_start((struct hv_start_fcopy *)fcopy_msg);
323 	case WRITE_TO_FILE:
324 		return hv_copy_data((struct hv_do_fcopy *)fcopy_msg);
325 	case COMPLETE_FCOPY:
326 		return hv_copy_finished();
327 	}
328 
329 	return HV_E_FAIL;
330 }
331 
332 /* process the packet recv from host */
333 static int fcopy_pkt_process(struct vmbus_br *txbr)
334 {
335 	int ret, offset, pktlen;
336 	int fcopy_srv_version;
337 	const struct vmbus_chanpkt_hdr *pkt;
338 	struct hv_fcopy_hdr *fcopy_msg;
339 	struct icmsg_hdr *icmsghdr;
340 
341 	pkt = (const struct vmbus_chanpkt_hdr *)desc;
342 	offset = pkt->hlen << 3;
343 	pktlen = (pkt->tlen << 3) - offset;
344 	icmsghdr = (struct icmsg_hdr *)&desc[offset + sizeof(struct vmbuspipe_hdr)];
345 	icmsghdr->status = HV_E_FAIL;
346 
347 	if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
348 		if (vmbus_prep_negotiate_resp(icmsghdr, desc + offset, pktlen, fw_versions,
349 					      FW_VER_COUNT, fcopy_versions, FCOPY_VER_COUNT,
350 					      NULL, &fcopy_srv_version)) {
351 			syslog(LOG_INFO, "FCopy IC version %d.%d",
352 			       fcopy_srv_version >> 16, fcopy_srv_version & 0xFFFF);
353 			icmsghdr->status = 0;
354 		}
355 	} else if (icmsghdr->icmsgtype == ICMSGTYPE_FCOPY) {
356 		/* Ensure recvlen is big enough to contain hv_fcopy_hdr */
357 		if (pktlen < ICMSG_HDR + sizeof(struct hv_fcopy_hdr)) {
358 			syslog(LOG_ERR, "Invalid Fcopy hdr. Packet length too small: %u",
359 			       pktlen);
360 			return -ENOBUFS;
361 		}
362 
363 		fcopy_msg = (struct hv_fcopy_hdr *)&desc[offset + ICMSG_HDR];
364 		icmsghdr->status = hv_fcopy_send_data(fcopy_msg, pktlen);
365 	}
366 
367 	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
368 	ret = rte_vmbus_chan_send(txbr, 0x6, desc + offset, pktlen, 0);
369 	if (ret) {
370 		syslog(LOG_ERR, "Write to ringbuffer failed err: %d", ret);
371 		return ret;
372 	}
373 
374 	return 0;
375 }
376 
377 static void fcopy_get_first_folder(char *path, char *chan_no)
378 {
379 	DIR *dir = opendir(path);
380 	struct dirent *entry;
381 
382 	if (!dir) {
383 		syslog(LOG_ERR, "Failed to open directory (errno=%s).\n", strerror(errno));
384 		return;
385 	}
386 
387 	while ((entry = readdir(dir)) != NULL) {
388 		if (entry->d_type == DT_DIR && strcmp(entry->d_name, ".") != 0 &&
389 		    strcmp(entry->d_name, "..") != 0) {
390 			strcpy(chan_no, entry->d_name);
391 			break;
392 		}
393 	}
394 
395 	closedir(dir);
396 }
397 
398 int main(int argc, char *argv[])
399 {
400 	int fcopy_fd = -1, tmp = 1;
401 	int daemonize = 1, long_index = 0, opt, ret = -EINVAL;
402 	struct vmbus_br txbr, rxbr;
403 	void *ring;
404 	uint32_t len = HV_RING_SIZE;
405 	char uio_name[MAX_FOLDER_NAME] = {0};
406 	char uio_dev_path[MAX_PATH_LEN] = {0};
407 
408 	static struct option long_options[] = {
409 		{"help",	no_argument,	   0,  'h' },
410 		{"no-daemon",	no_argument,	   0,  'n' },
411 		{0,		0,		   0,  0   }
412 	};
413 
414 	while ((opt = getopt_long(argc, argv, "hn", long_options,
415 				  &long_index)) != -1) {
416 		switch (opt) {
417 		case 'n':
418 			daemonize = 0;
419 			break;
420 		case 'h':
421 		default:
422 			print_usage(argv);
423 			goto exit;
424 		}
425 	}
426 
427 	if (daemonize && daemon(1, 0)) {
428 		syslog(LOG_ERR, "daemon() failed; error: %s", strerror(errno));
429 		goto exit;
430 	}
431 
432 	openlog("HV_UIO_FCOPY", 0, LOG_USER);
433 	syslog(LOG_INFO, "starting; pid is:%d", getpid());
434 
435 	fcopy_get_first_folder(FCOPY_UIO, uio_name);
436 	snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name);
437 	fcopy_fd = open(uio_dev_path, O_RDWR);
438 
439 	if (fcopy_fd < 0) {
440 		syslog(LOG_ERR, "open %s failed; error: %d %s",
441 		       uio_dev_path, errno, strerror(errno));
442 		ret = fcopy_fd;
443 		goto exit;
444 	}
445 
446 	ring = vmbus_uio_map(&fcopy_fd, HV_RING_SIZE);
447 	if (!ring) {
448 		ret = errno;
449 		syslog(LOG_ERR, "mmap ringbuffer failed; error: %d %s", ret, strerror(ret));
450 		goto close;
451 	}
452 	vmbus_br_setup(&txbr, ring, HV_RING_SIZE);
453 	vmbus_br_setup(&rxbr, (char *)ring + HV_RING_SIZE, HV_RING_SIZE);
454 
455 	rxbr.vbr->imask = 0;
456 
457 	while (1) {
458 		/*
459 		 * In this loop we process fcopy messages after the
460 		 * handshake is complete.
461 		 */
462 		ret = pread(fcopy_fd, &tmp, sizeof(int), 0);
463 		if (ret < 0) {
464 			syslog(LOG_ERR, "pread failed: %s", strerror(errno));
465 			continue;
466 		}
467 
468 		len = HV_RING_SIZE;
469 		ret = rte_vmbus_chan_recv_raw(&rxbr, desc, &len);
470 		if (unlikely(ret <= 0)) {
471 			/* This indicates a failure to communicate (or worse) */
472 			syslog(LOG_ERR, "VMBus channel recv error: %d", ret);
473 		} else {
474 			ret = fcopy_pkt_process(&txbr);
475 			if (ret < 0)
476 				goto close;
477 
478 			/* Signal host */
479 			if ((write(fcopy_fd, &tmp, sizeof(int))) != sizeof(int)) {
480 				ret = errno;
481 				syslog(LOG_ERR, "Signal to host failed: %s\n", strerror(ret));
482 				goto close;
483 			}
484 		}
485 	}
486 close:
487 	close(fcopy_fd);
488 exit:
489 	return ret;
490 }
491