summaryrefslogtreecommitdiff
path: root/tools/hv/hv_fcopy_daemon.c
blob: 785f4e95148cf13a48458c00147162ef503d6ef6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
/*
 * An implementation of host to guest copy functionality for Linux.
 *
 * Copyright (C) 2014, Microsoft, Inc.
 *
 * Author : K. Y. Srinivasan <kys@microsoft.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 */


#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <linux/hyperv.h>
#include <linux/limits.h>
#include <syslog.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <getopt.h>

static int target_fd;
static char target_fname[PATH_MAX];
static unsigned long long filesize;

static int hv_start_fcopy(struct hv_start_fcopy *smsg)
{
	int error = HV_E_FAIL;
	char *q, *p;

	filesize = 0;
	p = (char *)smsg->path_name;
	snprintf(target_fname, sizeof(target_fname), "%s/%s",
		 (char *)smsg->path_name, (char *)smsg->file_name);

	syslog(LOG_INFO, "Target file name: %s", target_fname);
	/*
	 * Check to see if the path is already in place; if not,
	 * create if required.
	 */
	while ((q = strchr(p, '/')) != NULL) {
		if (q == p) {
			p++;
			continue;
		}
		*q = '\0';
		if (access((char *)smsg->path_name, F_OK)) {
			if (smsg->copy_flags & CREATE_PATH) {
				if (mkdir((char *)smsg->path_name, 0755)) {
					syslog(LOG_ERR, "Failed to create %s",
						(char *)smsg->path_name);
					goto done;
				}
			} else {
				syslog(LOG_ERR, "Invalid path: %s",
					(char *)smsg->path_name);
				goto done;
			}
		}
		p = q + 1;
		*q = '/';
	}

	if (!access(target_fname, F_OK)) {
		syslog(LOG_INFO, "File: %s exists", target_fname);
		if (!(smsg->copy_flags & OVER_WRITE)) {
			error = HV_ERROR_ALREADY_EXISTS;
			goto done;
		}
	}

	target_fd = open(target_fname,
			 O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0744);
	if (target_fd == -1) {
		syslog(LOG_INFO, "Open Failed: %s", strerror(errno));
		goto done;
	}

	error = 0;
done:
	return error;
}

static int hv_copy_data(struct hv_do_fcopy *cpmsg)
{
	ssize_t bytes_written;
	int ret = 0;

	bytes_written = pwrite(target_fd, cpmsg->data, cpmsg->size,
				cpmsg->offset);

	filesize += cpmsg->size;
	if (bytes_written != cpmsg->size) {
		switch (errno) {
		case ENOSPC:
			ret = HV_ERROR_DISK_FULL;
			break;
		default:
			ret = HV_E_FAIL;
			break;
		}
		syslog(LOG_ERR, "pwrite failed to write %llu bytes: %ld (%s)",
		       filesize, (long)bytes_written, strerror(errno));
	}

	return ret;
}

static int hv_copy_finished(void)
{
	close(target_fd);
	return 0;
}
static int hv_copy_cancel(void)
{
	close(target_fd);
	unlink(target_fname);
	return 0;

}

void print_usage(char *argv[])
{
	fprintf(stderr, "Usage: %s [options]\n"
		"Options are:\n"
		"  -n, --no-daemon        stay in foreground, don't daemonize\n"
		"  -h, --help             print this help\n", argv[0]);
}

int main(int argc, char *argv[])
{
	int fcopy_fd;
	int error;
	int daemonize = 1, long_index = 0, opt;
	int version = FCOPY_CURRENT_VERSION;
	union {
		struct hv_fcopy_hdr hdr;
		struct hv_start_fcopy start;
		struct hv_do_fcopy copy;
		__u32 kernel_modver;
	} buffer = { };
	int in_handshake = 1;

	static struct option long_options[] = {
		{"help",	no_argument,	   0,  'h' },
		{"no-daemon",	no_argument,	   0,  'n' },
		{0,		0,		   0,  0   }
	};

	while ((opt = getopt_long(argc, argv, "hn", long_options,
				  &long_index)) != -1) {
		switch (opt) {
		case 'n':
			daemonize = 0;
			break;
		case 'h':
		default:
			print_usage(argv);
			exit(EXIT_FAILURE);
		}
	}

	if (daemonize && daemon(1, 0)) {
		syslog(LOG_ERR, "daemon() failed; error: %s", strerror(errno));
		exit(EXIT_FAILURE);
	}

	openlog("HV_FCOPY", 0, LOG_USER);
	syslog(LOG_INFO, "starting; pid is:%d", getpid());

	fcopy_fd = open("/dev/vmbus/hv_fcopy", O_RDWR);

	if (fcopy_fd < 0) {
		syslog(LOG_ERR, "open /dev/vmbus/hv_fcopy failed; error: %d %s",
			errno, strerror(errno));
		exit(EXIT_FAILURE);
	}

	/*
	 * Register with the kernel.
	 */
	if ((write(fcopy_fd, &version, sizeof(int))) != sizeof(int)) {
		syslog(LOG_ERR, "Registration failed: %s", strerror(errno));
		exit(EXIT_FAILURE);
	}

	while (1) {
		/*
		 * In this loop we process fcopy messages after the
		 * handshake is complete.
		 */
		ssize_t len;

		len = pread(fcopy_fd, &buffer, sizeof(buffer), 0);
		if (len < 0) {
			syslog(LOG_ERR, "pread failed: %s", strerror(errno));
			exit(EXIT_FAILURE);
		}

		if (in_handshake) {
			if (len != sizeof(buffer.kernel_modver)) {
				syslog(LOG_ERR, "invalid version negotiation");
				exit(EXIT_FAILURE);
			}
			in_handshake = 0;
			syslog(LOG_INFO, "kernel module version: %u",
			       buffer.kernel_modver);
			continue;
		}

		switch (buffer.hdr.operation) {
		case START_FILE_COPY:
			error = hv_start_fcopy(&buffer.start);
			break;
		case WRITE_TO_FILE:
			error = hv_copy_data(&buffer.copy);
			break;
		case COMPLETE_FCOPY:
			error = hv_copy_finished();
			break;
		case CANCEL_FCOPY:
			error = hv_copy_cancel();
			break;

		default:
			syslog(LOG_ERR, "Unknown operation: %d",
				buffer.hdr.operation);

		}

		if (pwrite(fcopy_fd, &error, sizeof(int), 0) != sizeof(int)) {
			syslog(LOG_ERR, "pwrite failed: %s", strerror(errno));
			exit(EXIT_FAILURE);
		}
	}
}