Commit | Line | Data |
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96dd86fa S |
1 | /* |
2 | * An implementation of the host initiated guest snapshot for Hyper-V. | |
3 | * | |
4 | * | |
5 | * Copyright (C) 2013, Microsoft, Inc. | |
6 | * Author : K. Y. Srinivasan <kys@microsoft.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License version 2 as published | |
10 | * by the Free Software Foundation. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, but | |
13 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | |
15 | * NON INFRINGEMENT. See the GNU General Public License for more | |
16 | * details. | |
17 | * | |
18 | */ | |
19 | ||
20 | ||
21 | #include <sys/types.h> | |
22 | #include <sys/socket.h> | |
23 | #include <sys/poll.h> | |
7b413b65 | 24 | #include <sys/ioctl.h> |
96dd86fa | 25 | #include <linux/types.h> |
7b413b65 | 26 | #include <fcntl.h> |
96dd86fa | 27 | #include <stdio.h> |
d3d1ee3a | 28 | #include <mntent.h> |
96dd86fa S |
29 | #include <stdlib.h> |
30 | #include <unistd.h> | |
31 | #include <string.h> | |
32 | #include <ctype.h> | |
33 | #include <errno.h> | |
34 | #include <arpa/inet.h> | |
7b413b65 | 35 | #include <linux/fs.h> |
96dd86fa S |
36 | #include <linux/connector.h> |
37 | #include <linux/hyperv.h> | |
38 | #include <linux/netlink.h> | |
39 | #include <syslog.h> | |
40 | ||
96dd86fa S |
41 | static struct sockaddr_nl addr; |
42 | ||
43 | #ifndef SOL_NETLINK | |
44 | #define SOL_NETLINK 270 | |
45 | #endif | |
46 | ||
47 | ||
7b413b65 OH |
48 | static int vss_do_freeze(char *dir, unsigned int cmd, char *fs_op) |
49 | { | |
50 | int ret, fd = open(dir, O_RDONLY); | |
51 | ||
52 | if (fd < 0) | |
53 | return 1; | |
54 | ret = ioctl(fd, cmd, 0); | |
55 | syslog(LOG_INFO, "VSS: %s of %s: %s\n", fs_op, dir, strerror(errno)); | |
56 | close(fd); | |
57 | return !!ret; | |
58 | } | |
59 | ||
96dd86fa S |
60 | static int vss_operate(int operation) |
61 | { | |
62 | char *fs_op; | |
d3d1ee3a OH |
63 | char match[] = "/dev/"; |
64 | FILE *mounts; | |
65 | struct mntent *ent; | |
7b413b65 | 66 | unsigned int cmd; |
d3d1ee3a | 67 | int error = 0, root_seen = 0; |
96dd86fa S |
68 | |
69 | switch (operation) { | |
70 | case VSS_OP_FREEZE: | |
7b413b65 OH |
71 | cmd = FIFREEZE; |
72 | fs_op = "freeze"; | |
96dd86fa S |
73 | break; |
74 | case VSS_OP_THAW: | |
7b413b65 OH |
75 | cmd = FITHAW; |
76 | fs_op = "thaw"; | |
96dd86fa | 77 | break; |
eb8905b8 OH |
78 | default: |
79 | return -1; | |
96dd86fa S |
80 | } |
81 | ||
d3d1ee3a OH |
82 | mounts = setmntent("/proc/mounts", "r"); |
83 | if (mounts == NULL) | |
eb8905b8 | 84 | return -1; |
96dd86fa | 85 | |
0e272639 | 86 | while ((ent = getmntent(mounts))) { |
d3d1ee3a | 87 | if (strncmp(ent->mnt_fsname, match, strlen(match))) |
96dd86fa | 88 | continue; |
10b637b4 OH |
89 | if (strcmp(ent->mnt_type, "iso9660") == 0) |
90 | continue; | |
d3d1ee3a OH |
91 | if (strcmp(ent->mnt_dir, "/") == 0) { |
92 | root_seen = 1; | |
93 | continue; | |
94 | } | |
7b413b65 | 95 | error |= vss_do_freeze(ent->mnt_dir, cmd, fs_op); |
96dd86fa | 96 | } |
d3d1ee3a | 97 | endmntent(mounts); |
96dd86fa | 98 | |
d3d1ee3a | 99 | if (root_seen) { |
7b413b65 | 100 | error |= vss_do_freeze("/", cmd, fs_op); |
d3d1ee3a | 101 | } |
96dd86fa S |
102 | |
103 | return error; | |
104 | } | |
105 | ||
106 | static int netlink_send(int fd, struct cn_msg *msg) | |
107 | { | |
108 | struct nlmsghdr *nlh; | |
109 | unsigned int size; | |
110 | struct msghdr message; | |
111 | char buffer[64]; | |
112 | struct iovec iov[2]; | |
113 | ||
114 | size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len); | |
115 | ||
116 | nlh = (struct nlmsghdr *)buffer; | |
117 | nlh->nlmsg_seq = 0; | |
118 | nlh->nlmsg_pid = getpid(); | |
119 | nlh->nlmsg_type = NLMSG_DONE; | |
120 | nlh->nlmsg_len = NLMSG_LENGTH(size - sizeof(*nlh)); | |
121 | nlh->nlmsg_flags = 0; | |
122 | ||
123 | iov[0].iov_base = nlh; | |
124 | iov[0].iov_len = sizeof(*nlh); | |
125 | ||
126 | iov[1].iov_base = msg; | |
127 | iov[1].iov_len = size; | |
128 | ||
129 | memset(&message, 0, sizeof(message)); | |
130 | message.msg_name = &addr; | |
131 | message.msg_namelen = sizeof(addr); | |
132 | message.msg_iov = iov; | |
133 | message.msg_iovlen = 2; | |
134 | ||
135 | return sendmsg(fd, &message, 0); | |
136 | } | |
137 | ||
138 | int main(void) | |
139 | { | |
140 | int fd, len, nl_group; | |
141 | int error; | |
142 | struct cn_msg *message; | |
143 | struct pollfd pfd; | |
144 | struct nlmsghdr *incoming_msg; | |
145 | struct cn_msg *incoming_cn_msg; | |
146 | int op; | |
147 | struct hv_vss_msg *vss_msg; | |
b4919a5f OH |
148 | char *vss_send_buffer; |
149 | char *vss_recv_buffer; | |
150 | size_t vss_recv_buffer_len; | |
96dd86fa | 151 | |
eb8905b8 OH |
152 | if (daemon(1, 0)) |
153 | return 1; | |
154 | ||
96dd86fa S |
155 | openlog("Hyper-V VSS", 0, LOG_USER); |
156 | syslog(LOG_INFO, "VSS starting; pid is:%d", getpid()); | |
157 | ||
b4919a5f OH |
158 | vss_recv_buffer_len = NLMSG_HDRLEN + sizeof(struct cn_msg) + sizeof(struct hv_vss_msg); |
159 | vss_send_buffer = calloc(1, vss_recv_buffer_len); | |
160 | vss_recv_buffer = calloc(1, vss_recv_buffer_len); | |
161 | if (!(vss_send_buffer && vss_recv_buffer)) { | |
162 | syslog(LOG_ERR, "Failed to allocate netlink buffers"); | |
163 | exit(EXIT_FAILURE); | |
164 | } | |
165 | ||
96dd86fa S |
166 | fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR); |
167 | if (fd < 0) { | |
5c289269 TH |
168 | syslog(LOG_ERR, "netlink socket creation failed; error:%d %s", |
169 | errno, strerror(errno)); | |
96dd86fa S |
170 | exit(EXIT_FAILURE); |
171 | } | |
172 | addr.nl_family = AF_NETLINK; | |
173 | addr.nl_pad = 0; | |
174 | addr.nl_pid = 0; | |
175 | addr.nl_groups = 0; | |
176 | ||
177 | ||
178 | error = bind(fd, (struct sockaddr *)&addr, sizeof(addr)); | |
179 | if (error < 0) { | |
5c289269 | 180 | syslog(LOG_ERR, "bind failed; error:%d %s", errno, strerror(errno)); |
96dd86fa S |
181 | close(fd); |
182 | exit(EXIT_FAILURE); | |
183 | } | |
184 | nl_group = CN_VSS_IDX; | |
d12e1469 TH |
185 | if (setsockopt(fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &nl_group, sizeof(nl_group)) < 0) { |
186 | syslog(LOG_ERR, "setsockopt failed; error:%d %s", errno, strerror(errno)); | |
187 | close(fd); | |
188 | exit(EXIT_FAILURE); | |
189 | } | |
96dd86fa S |
190 | /* |
191 | * Register ourselves with the kernel. | |
192 | */ | |
193 | message = (struct cn_msg *)vss_send_buffer; | |
194 | message->id.idx = CN_VSS_IDX; | |
195 | message->id.val = CN_VSS_VAL; | |
196 | message->ack = 0; | |
197 | vss_msg = (struct hv_vss_msg *)message->data; | |
198 | vss_msg->vss_hdr.operation = VSS_OP_REGISTER; | |
199 | ||
200 | message->len = sizeof(struct hv_vss_msg); | |
201 | ||
202 | len = netlink_send(fd, message); | |
203 | if (len < 0) { | |
5c289269 | 204 | syslog(LOG_ERR, "netlink_send failed; error:%d %s", errno, strerror(errno)); |
96dd86fa S |
205 | close(fd); |
206 | exit(EXIT_FAILURE); | |
207 | } | |
208 | ||
209 | pfd.fd = fd; | |
210 | ||
211 | while (1) { | |
212 | struct sockaddr *addr_p = (struct sockaddr *) &addr; | |
213 | socklen_t addr_l = sizeof(addr); | |
214 | pfd.events = POLLIN; | |
215 | pfd.revents = 0; | |
9561d479 TH |
216 | |
217 | if (poll(&pfd, 1, -1) < 0) { | |
218 | syslog(LOG_ERR, "poll failed; error:%d %s", errno, strerror(errno)); | |
219 | if (errno == EINVAL) { | |
220 | close(fd); | |
221 | exit(EXIT_FAILURE); | |
222 | } | |
223 | else | |
224 | continue; | |
225 | } | |
96dd86fa | 226 | |
b4919a5f | 227 | len = recvfrom(fd, vss_recv_buffer, vss_recv_buffer_len, 0, |
96dd86fa S |
228 | addr_p, &addr_l); |
229 | ||
5edf5ee4 | 230 | if (len < 0) { |
96dd86fa S |
231 | syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s", |
232 | addr.nl_pid, errno, strerror(errno)); | |
233 | close(fd); | |
234 | return -1; | |
235 | } | |
236 | ||
5edf5ee4 | 237 | if (addr.nl_pid) { |
038336a5 S |
238 | syslog(LOG_WARNING, |
239 | "Received packet from untrusted pid:%u", | |
240 | addr.nl_pid); | |
5edf5ee4 OH |
241 | continue; |
242 | } | |
243 | ||
96dd86fa S |
244 | incoming_msg = (struct nlmsghdr *)vss_recv_buffer; |
245 | ||
246 | if (incoming_msg->nlmsg_type != NLMSG_DONE) | |
247 | continue; | |
248 | ||
249 | incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg); | |
250 | vss_msg = (struct hv_vss_msg *)incoming_cn_msg->data; | |
251 | op = vss_msg->vss_hdr.operation; | |
252 | error = HV_S_OK; | |
253 | ||
254 | switch (op) { | |
255 | case VSS_OP_FREEZE: | |
256 | case VSS_OP_THAW: | |
257 | error = vss_operate(op); | |
258 | if (error) | |
259 | error = HV_E_FAIL; | |
260 | break; | |
261 | default: | |
262 | syslog(LOG_ERR, "Illegal op:%d\n", op); | |
263 | } | |
264 | vss_msg->error = error; | |
265 | len = netlink_send(fd, incoming_cn_msg); | |
266 | if (len < 0) { | |
5c289269 TH |
267 | syslog(LOG_ERR, "net_link send failed; error:%d %s", |
268 | errno, strerror(errno)); | |
96dd86fa S |
269 | exit(EXIT_FAILURE); |
270 | } | |
271 | } | |
272 | ||
273 | } |