[deliverable/linux.git] / tools / hv / hv_vss_daemon.c

/*
 * An implementation of the host initiated guest snapshot for Hyper-V.
 *
 *
 * Copyright (C) 2013, 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 <sys/socket.h>
#include <sys/poll.h>
#include <linux/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <arpa/inet.h>
#include <linux/connector.h>
#include <linux/hyperv.h>
#include <linux/netlink.h>
#include <syslog.h>

static char vss_recv_buffer[4096];
static char vss_send_buffer[4096];
static struct sockaddr_nl addr;

#ifndef SOL_NETLINK
#define SOL_NETLINK 270
#endif


static int vss_operate(int operation)
{
	char *fs_op;
	char cmd[512];
	char buf[512];
	FILE *file;
	char *p;
	char *x;
	int error = 0;

	switch (operation) {
	case VSS_OP_FREEZE:
		fs_op = "-f ";
		break;
	case VSS_OP_THAW:
		fs_op = "-u ";
		break;
	default:
		return -1;
	}

	file = popen("mount | awk '/^\\/dev\\// { print $3}'", "r");
	if (file == NULL)
		return -1;

	while ((p = fgets(buf, sizeof(buf), file)) != NULL) {
		x = strchr(p, '\n');
		*x = '\0';
		if (!strncmp(p, "/", sizeof("/")))
			continue;

		sprintf(cmd, "%s %s %s", "fsfreeze ", fs_op, p);
		syslog(LOG_INFO, "VSS cmd is %s\n", cmd);
		error = system(cmd);
	}
	pclose(file);

	sprintf(cmd, "%s %s %s", "fsfreeze ", fs_op, "/");
	syslog(LOG_INFO, "VSS cmd is %s\n", cmd);
	error = system(cmd);

	return error;
}

static int netlink_send(int fd, struct cn_msg *msg)
{
	struct nlmsghdr *nlh;
	unsigned int size;
	struct msghdr message;
	char buffer[64];
	struct iovec iov[2];

	size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len);

	nlh = (struct nlmsghdr *)buffer;
	nlh->nlmsg_seq = 0;
	nlh->nlmsg_pid = getpid();
	nlh->nlmsg_type = NLMSG_DONE;
	nlh->nlmsg_len = NLMSG_LENGTH(size - sizeof(*nlh));
	nlh->nlmsg_flags = 0;

	iov[0].iov_base = nlh;
	iov[0].iov_len = sizeof(*nlh);

	iov[1].iov_base = msg;
	iov[1].iov_len = size;

	memset(&message, 0, sizeof(message));
	message.msg_name = &addr;
	message.msg_namelen = sizeof(addr);
	message.msg_iov = iov;
	message.msg_iovlen = 2;

	return sendmsg(fd, &message, 0);
}

int main(void)
{
	int fd, len, nl_group;
	int error;
	struct cn_msg *message;
	struct pollfd pfd;
	struct nlmsghdr *incoming_msg;
	struct cn_msg	*incoming_cn_msg;
	int	op;
	struct hv_vss_msg *vss_msg;

	if (daemon(1, 0))
		return 1;

	openlog("Hyper-V VSS", 0, LOG_USER);
	syslog(LOG_INFO, "VSS starting; pid is:%d", getpid());

	fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
	if (fd < 0) {
		syslog(LOG_ERR, "netlink socket creation failed; error:%d", fd);
		exit(EXIT_FAILURE);
	}
	addr.nl_family = AF_NETLINK;
	addr.nl_pad = 0;
	addr.nl_pid = 0;
	addr.nl_groups = 0;


	error = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
	if (error < 0) {
		syslog(LOG_ERR, "bind failed; error:%d", error);
		close(fd);
		exit(EXIT_FAILURE);
	}
	nl_group = CN_VSS_IDX;
	setsockopt(fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &nl_group, sizeof(nl_group));
	/*
	 * Register ourselves with the kernel.
	 */
	message = (struct cn_msg *)vss_send_buffer;
	message->id.idx = CN_VSS_IDX;
	message->id.val = CN_VSS_VAL;
	message->ack = 0;
	vss_msg = (struct hv_vss_msg *)message->data;
	vss_msg->vss_hdr.operation = VSS_OP_REGISTER;

	message->len = sizeof(struct hv_vss_msg);

	len = netlink_send(fd, message);
	if (len < 0) {
		syslog(LOG_ERR, "netlink_send failed; error:%d", len);
		close(fd);
		exit(EXIT_FAILURE);
	}

	pfd.fd = fd;

	while (1) {
		struct sockaddr *addr_p = (struct sockaddr *) &addr;
		socklen_t addr_l = sizeof(addr);
		pfd.events = POLLIN;
		pfd.revents = 0;
		poll(&pfd, 1, -1);

		len = recvfrom(fd, vss_recv_buffer, sizeof(vss_recv_buffer), 0,
				addr_p, &addr_l);

		if (len < 0 || addr.nl_pid) {
			syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s",
					addr.nl_pid, errno, strerror(errno));
			close(fd);
			return -1;
		}

		incoming_msg = (struct nlmsghdr *)vss_recv_buffer;

		if (incoming_msg->nlmsg_type != NLMSG_DONE)
			continue;

		incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg);
		vss_msg = (struct hv_vss_msg *)incoming_cn_msg->data;
		op = vss_msg->vss_hdr.operation;
		error =  HV_S_OK;

		switch (op) {
		case VSS_OP_FREEZE:
		case VSS_OP_THAW:
			error = vss_operate(op);
			if (error)
				error = HV_E_FAIL;
			break;
		default:
			syslog(LOG_ERR, "Illegal op:%d\n", op);
		}
		vss_msg->error = error;
		len = netlink_send(fd, incoming_cn_msg);
		if (len < 0) {
			syslog(LOG_ERR, "net_link send failed; error:%d", len);
			exit(EXIT_FAILURE);
		}
	}

}
Commit	Line	Data
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>
	24	#include <linux/types.h>
	25	#include <stdio.h>
	26	#include <stdlib.h>
	27	#include <unistd.h>
	28	#include <string.h>
	29	#include <ctype.h>
	30	#include <errno.h>
	31	#include <arpa/inet.h>
	32	#include <linux/connector.h>
	33	#include <linux/hyperv.h>
	34	#include <linux/netlink.h>
	35	#include <syslog.h>
	36
	37	static char vss_recv_buffer[4096];
	38	static char vss_send_buffer[4096];
	39	static struct sockaddr_nl addr;
	40
	41	#ifndef SOL_NETLINK
	42	#define SOL_NETLINK 270
	43	#endif
	44
	45
	46	static int vss_operate(int operation)
	47	{
	48	char *fs_op;
	49	char cmd[512];
	50	char buf[512];
	51	FILE *file;
	52	char *p;
	53	char *x;
eb8905b8	54	int error = 0;
96dd86fa S	55
	56	switch (operation) {
	57	case VSS_OP_FREEZE:
	58	fs_op = "-f ";
	59	break;
	60	case VSS_OP_THAW:
	61	fs_op = "-u ";
	62	break;
eb8905b8 OH	63	default:
eb8905b8 OH	64	return -1;
96dd86fa S	65	}
96dd86fa S	66
eb8905b8	67	file = popen("mount \| awk '/^\\/dev\\// { print $3}'", "r");
96dd86fa	68	if (file == NULL)
eb8905b8	69	return -1;
96dd86fa S	70
	71	while ((p = fgets(buf, sizeof(buf), file)) != NULL) {
	72	x = strchr(p, '\n');
	73	*x = '\0';
	74	if (!strncmp(p, "/", sizeof("/")))
	75	continue;
	76
	77	sprintf(cmd, "%s %s %s", "fsfreeze ", fs_op, p);
	78	syslog(LOG_INFO, "VSS cmd is %s\n", cmd);
	79	error = system(cmd);
	80	}
	81	pclose(file);
	82
	83	sprintf(cmd, "%s %s %s", "fsfreeze ", fs_op, "/");
	84	syslog(LOG_INFO, "VSS cmd is %s\n", cmd);
	85	error = system(cmd);
	86
	87	return error;
	88	}
	89
	90	static int netlink_send(int fd, struct cn_msg *msg)
	91	{
	92	struct nlmsghdr *nlh;
	93	unsigned int size;
	94	struct msghdr message;
	95	char buffer[64];
	96	struct iovec iov[2];
	97
	98	size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len);
	99
	100	nlh = (struct nlmsghdr *)buffer;
	101	nlh->nlmsg_seq = 0;
	102	nlh->nlmsg_pid = getpid();
	103	nlh->nlmsg_type = NLMSG_DONE;
	104	nlh->nlmsg_len = NLMSG_LENGTH(size - sizeof(*nlh));
	105	nlh->nlmsg_flags = 0;
	106
	107	iov[0].iov_base = nlh;
	108	iov[0].iov_len = sizeof(*nlh);
	109
	110	iov[1].iov_base = msg;
	111	iov[1].iov_len = size;
	112
	113	memset(&message, 0, sizeof(message));
	114	message.msg_name = &addr;
	115	message.msg_namelen = sizeof(addr);
	116	message.msg_iov = iov;
	117	message.msg_iovlen = 2;
	118
	119	return sendmsg(fd, &message, 0);
	120	}
	121
	122	int main(void)
	123	{
	124	int fd, len, nl_group;
	125	int error;
	126	struct cn_msg *message;
	127	struct pollfd pfd;
	128	struct nlmsghdr *incoming_msg;
	129	struct cn_msg *incoming_cn_msg;
	130	int op;
	131	struct hv_vss_msg *vss_msg;
	132
eb8905b8 OH	133	if (daemon(1, 0))
	134	return 1;
	135
96dd86fa S	136	openlog("Hyper-V VSS", 0, LOG_USER);
	137	syslog(LOG_INFO, "VSS starting; pid is:%d", getpid());
	138
	139	fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
	140	if (fd < 0) {
	141	syslog(LOG_ERR, "netlink socket creation failed; error:%d", fd);
	142	exit(EXIT_FAILURE);
	143	}
	144	addr.nl_family = AF_NETLINK;
	145	addr.nl_pad = 0;
	146	addr.nl_pid = 0;
	147	addr.nl_groups = 0;
	148
	149
	150	error = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
	151	if (error < 0) {
	152	syslog(LOG_ERR, "bind failed; error:%d", error);
	153	close(fd);
	154	exit(EXIT_FAILURE);
	155	}
	156	nl_group = CN_VSS_IDX;
	157	setsockopt(fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &nl_group, sizeof(nl_group));
	158	/*
	159	* Register ourselves with the kernel.
	160	*/
	161	message = (struct cn_msg *)vss_send_buffer;
	162	message->id.idx = CN_VSS_IDX;
	163	message->id.val = CN_VSS_VAL;
	164	message->ack = 0;
	165	vss_msg = (struct hv_vss_msg *)message->data;
	166	vss_msg->vss_hdr.operation = VSS_OP_REGISTER;
	167
	168	message->len = sizeof(struct hv_vss_msg);
	169
	170	len = netlink_send(fd, message);
	171	if (len < 0) {
	172	syslog(LOG_ERR, "netlink_send failed; error:%d", len);
	173	close(fd);
	174	exit(EXIT_FAILURE);
	175	}
	176
	177	pfd.fd = fd;
	178
	179	while (1) {
	180	struct sockaddr addr_p = (struct sockaddr ) &addr;
	181	socklen_t addr_l = sizeof(addr);
	182	pfd.events = POLLIN;
	183	pfd.revents = 0;
	184	poll(&pfd, 1, -1);
	185
	186	len = recvfrom(fd, vss_recv_buffer, sizeof(vss_recv_buffer), 0,
	187	addr_p, &addr_l);
	188
	189	if (len < 0 \|\| addr.nl_pid) {
	190	syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s",
	191	addr.nl_pid, errno, strerror(errno));
	192	close(fd);
	193	return -1;
	194	}
	195
	196	incoming_msg = (struct nlmsghdr *)vss_recv_buffer;
	197
	198	if (incoming_msg->nlmsg_type != NLMSG_DONE)
	199	continue;
200
201	incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg);
202	vss_msg = (struct hv_vss_msg *)incoming_cn_msg->data;
203	op = vss_msg->vss_hdr.operation;
204	error = HV_S_OK;
205
206	switch (op) {
207	case VSS_OP_FREEZE:
208	case VSS_OP_THAW:
209	error = vss_operate(op);
210	if (error)
211	error = HV_E_FAIL;
212	break;
213	default:
214	syslog(LOG_ERR, "Illegal op:%d\n", op);
215	}
216	vss_msg->error = error;
217	len = netlink_send(fd, incoming_cn_msg);
218	if (len < 0) {
219	syslog(LOG_ERR, "net_link send failed; error:%d", len);
220	exit(EXIT_FAILURE);
221	}
222	}
223
224	}