forked from kvmtool/kvmtool
-
Notifications
You must be signed in to change notification settings - Fork 0
/
builtin-setup.c
285 lines (226 loc) · 5.52 KB
/
builtin-setup.c
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
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
#include <kvm/util.h>
#include <kvm/kvm-cmd.h>
#include <kvm/builtin-setup.h>
#include <kvm/kvm.h>
#include <kvm/parse-options.h>
#include <kvm/read-write.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <limits.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/mman.h>
#include <fcntl.h>
static const char *instance_name;
static const char * const setup_usage[] = {
"lkvm setup [name]",
NULL
};
static const struct option setup_options[] = {
OPT_END()
};
static void parse_setup_options(int argc, const char **argv)
{
while (argc != 0) {
argc = parse_options(argc, argv, setup_options, setup_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
if (argc != 0 && instance_name)
kvm_setup_help();
else
instance_name = argv[0];
argv++;
argc--;
}
}
void kvm_setup_help(void)
{
printf("\n%s setup creates a new rootfs under %s.\n"
"This can be used later by the '-d' parameter of '%s run'.\n",
KVM_BINARY_NAME, kvm__get_dir(), KVM_BINARY_NAME);
usage_with_options(setup_usage, setup_options);
}
static int copy_file(const char *from, const char *to)
{
int in_fd, out_fd;
void *src, *dst;
struct stat st;
int err = -1;
in_fd = open(from, O_RDONLY);
if (in_fd < 0)
return err;
if (fstat(in_fd, &st) < 0)
goto error_close_in;
out_fd = open(to, O_RDWR | O_CREAT | O_TRUNC, st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO));
if (out_fd < 0)
goto error_close_in;
src = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, in_fd, 0);
if (src == MAP_FAILED)
goto error_close_out;
if (ftruncate(out_fd, st.st_size) < 0)
goto error_munmap_src;
dst = mmap(NULL, st.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, out_fd, 0);
if (dst == MAP_FAILED)
goto error_munmap_src;
memcpy(dst, src, st.st_size);
if (fsync(out_fd) < 0)
goto error_munmap_dst;
err = 0;
error_munmap_dst:
munmap(dst, st.st_size);
error_munmap_src:
munmap(src, st.st_size);
error_close_out:
close(out_fd);
error_close_in:
close(in_fd);
return err;
}
static const char *guestfs_dirs[] = {
"/dev",
"/etc",
"/home",
"/host",
"/proc",
"/root",
"/sys",
"/tmp",
"/var",
"/var/lib",
"/virt",
"/virt/home",
};
static const char *guestfs_symlinks[] = {
"/bin",
"/lib",
"/lib64",
"/sbin",
"/usr",
"/etc/ld.so.conf",
};
#ifdef CONFIG_GUEST_INIT
static int extract_file(const char *guestfs_name, const char *filename,
const void *data, size_t size)
{
char path[PATH_MAX];
int fd, ret;
snprintf(path, PATH_MAX, "%s%s/%s", kvm__get_dir(),
guestfs_name, filename);
fd = open(path, O_EXCL | O_CREAT | O_WRONLY, 0755);
if (fd < 0) {
if (errno == EEXIST)
return 0;
die("Fail to setup %s", path);
}
ret = xwrite(fd, data, size);
if (ret < 0)
die("Fail to setup %s", path);
close(fd);
return 0;
}
extern unsigned char init_binary[];
extern unsigned long init_binary_size;
extern unsigned char pre_init_binary[];
extern unsigned long pre_init_binary_size;
int kvm_setup_guest_init(const char *guestfs_name)
{
int err;
#ifdef CONFIG_GUEST_PRE_INIT
err = extract_file(guestfs_name, "virt/pre_init",
pre_init_binary, pre_init_binary_size);
if (err)
return err;
#endif
err = extract_file(guestfs_name, "virt/init",
init_binary, init_binary_size);
return err;
}
#else
int kvm_setup_guest_init(const char *guestfs_name)
{
die("Guest init image not compiled in");
return 0;
}
#endif
static int copy_passwd(const char *guestfs_name)
{
char path[PATH_MAX];
FILE *file;
int ret;
snprintf(path, PATH_MAX, "%s%s/etc/passwd", kvm__get_dir(), guestfs_name);
file = fopen(path, "w");
if (!file)
return -1;
ret = fprintf(file, "root:x:0:0:root:/root:/bin/sh\n");
if (ret > 0)
ret = 0;
fclose(file);
return ret;
}
static int make_guestfs_symlink(const char *guestfs_name, const char *path)
{
char target[PATH_MAX];
char name[PATH_MAX];
snprintf(name, PATH_MAX, "%s%s%s", kvm__get_dir(), guestfs_name, path);
snprintf(target, PATH_MAX, "/host%s", path);
return symlink(target, name);
}
static int make_dir(const char *dir)
{
char name[PATH_MAX];
snprintf(name, PATH_MAX, "%s%s", kvm__get_dir(), dir);
return mkdir(name, 0777);
}
static void make_guestfs_dir(const char *guestfs_name, const char *dir)
{
char name[PATH_MAX];
snprintf(name, PATH_MAX, "%s%s", guestfs_name, dir);
make_dir(name);
}
void kvm_setup_resolv(const char *guestfs_name)
{
char path[PATH_MAX];
snprintf(path, PATH_MAX, "%s%s/etc/resolv.conf", kvm__get_dir(), guestfs_name);
copy_file("/etc/resolv.conf", path);
}
static int do_setup(const char *guestfs_name)
{
unsigned int i;
int ret;
ret = make_dir(guestfs_name);
if (ret < 0)
return ret;
for (i = 0; i < ARRAY_SIZE(guestfs_dirs); i++)
make_guestfs_dir(guestfs_name, guestfs_dirs[i]);
for (i = 0; i < ARRAY_SIZE(guestfs_symlinks); i++) {
make_guestfs_symlink(guestfs_name, guestfs_symlinks[i]);
}
ret = kvm_setup_guest_init(guestfs_name);
if (ret < 0)
return ret;
return copy_passwd(guestfs_name);
}
int kvm_setup_create_new(const char *guestfs_name)
{
return do_setup(guestfs_name);
}
int kvm_cmd_setup(int argc, const char **argv, const char *prefix)
{
int r;
parse_setup_options(argc, argv);
if (instance_name == NULL)
kvm_setup_help();
r = do_setup(instance_name);
if (r == 0)
printf("A new rootfs '%s' has been created in '%s%s'.\n\n"
"You can now start it by running the following command:\n\n"
" %s run -d %s\n",
instance_name, kvm__get_dir(), instance_name,
KVM_BINARY_NAME,instance_name);
else
printf("Unable to create rootfs in %s%s: %s\n",
kvm__get_dir(), instance_name, strerror(errno));
return r;
}