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Tools: hv: vss: use misc char device to communicate with kernel

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Use /dev/vmbus/hv_vss instead of netlink.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Vitaly Kuznetsov 2015-04-11 18:07:56 -07:00 committed by Greg Kroah-Hartman
parent 8ddca80885
commit f5722b9bd4
1 changed files with 25 additions and 114 deletions
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139
tools/hv/hv_vss_daemon.c
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@ -19,7 +19,6 @@
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/poll.h>
#include <sys/ioctl.h>
#include <fcntl.h>
@ -30,21 +29,11 @@
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <arpa/inet.h>
#include <linux/fs.h>
#include <linux/connector.h>
#include <linux/hyperv.h>
#include <linux/netlink.h>
#include <syslog.h>
#include <getopt.h>
static struct sockaddr_nl addr;
#ifndef SOL_NETLINK
#define SOL_NETLINK 270
#endif
/* Don't use syslog() in the function since that can cause write to disk */
static int vss_do_freeze(char *dir, unsigned int cmd)
{
@ -143,33 +132,6 @@ out:
return error;
}
static int netlink_send(int fd, struct cn_msg *msg)
{
struct nlmsghdr nlh = { .nlmsg_type = NLMSG_DONE };
unsigned int size;
struct msghdr message;
struct iovec iov[2];
size = sizeof(struct cn_msg) + msg->len;
nlh.nlmsg_pid = getpid();
nlh.nlmsg_len = NLMSG_LENGTH(size);
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);
}
void print_usage(char *argv[])
{
fprintf(stderr, "Usage: %s [options]\n"
@ -180,16 +142,11 @@ void print_usage(char *argv[])
int main(int argc, char *argv[])
{
int fd, len, nl_group;
int vss_fd, len;
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;
char *vss_recv_buffer;
size_t vss_recv_buffer_len;
struct hv_vss_msg vss_msg[1];
int daemonize = 1, long_index = 0, opt;
static struct option long_options[] = {
@ -217,98 +174,50 @@ int main(int argc, char *argv[])
openlog("Hyper-V VSS", 0, LOG_USER);
syslog(LOG_INFO, "VSS starting; pid is:%d", getpid());
vss_recv_buffer_len = NLMSG_LENGTH(0) + sizeof(struct cn_msg) + sizeof(struct hv_vss_msg);
vss_recv_buffer = calloc(1, vss_recv_buffer_len);
if (!vss_recv_buffer) {
syslog(LOG_ERR, "Failed to allocate netlink buffers");
exit(EXIT_FAILURE);
}
fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
if (fd < 0) {
syslog(LOG_ERR, "netlink socket creation failed; error:%d %s",
errno, strerror(errno));
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 %s", errno, strerror(errno));
close(fd);
exit(EXIT_FAILURE);
}
nl_group = CN_VSS_IDX;
if (setsockopt(fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &nl_group, sizeof(nl_group)) < 0) {
syslog(LOG_ERR, "setsockopt failed; error:%d %s", errno, strerror(errno));
close(fd);
vss_fd = open("/dev/vmbus/hv_vss", O_RDWR);
if (vss_fd < 0) {
syslog(LOG_ERR, "open /dev/vmbus/hv_vss failed; error: %d %s",
errno, strerror(errno));
exit(EXIT_FAILURE);
}
/*
* Register ourselves with the kernel.
*/
message = (struct cn_msg *)vss_recv_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;
vss_msg->vss_hdr.operation = VSS_OP_REGISTER1;
message->len = sizeof(struct hv_vss_msg);
len = netlink_send(fd, message);
len = write(vss_fd, vss_msg, sizeof(struct hv_vss_msg));
if (len < 0) {
syslog(LOG_ERR, "netlink_send failed; error:%d %s", errno, strerror(errno));
close(fd);
syslog(LOG_ERR, "registration to kernel failed; error: %d %s",
errno, strerror(errno));
close(vss_fd);
exit(EXIT_FAILURE);
}
pfd.fd = fd;
pfd.fd = vss_fd;
while (1) {
struct sockaddr *addr_p = (struct sockaddr *) &addr;
socklen_t addr_l = sizeof(addr);
pfd.events = POLLIN;
pfd.revents = 0;
if (poll(&pfd, 1, -1) < 0) {
syslog(LOG_ERR, "poll failed; error:%d %s", errno, strerror(errno));
if (errno == EINVAL) {
close(fd);
close(vss_fd);
exit(EXIT_FAILURE);
}
else
continue;
}
len = recvfrom(fd, vss_recv_buffer, vss_recv_buffer_len, 0,
addr_p, &addr_l);
len = read(vss_fd, vss_msg, sizeof(struct hv_vss_msg));
if (len < 0) {
syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s",
addr.nl_pid, errno, strerror(errno));
close(fd);
return -1;
if (len != sizeof(struct hv_vss_msg)) {
syslog(LOG_ERR, "read failed; error:%d %s",
errno, strerror(errno));
close(vss_fd);
return EXIT_FAILURE;
}
if (addr.nl_pid) {
syslog(LOG_WARNING,
"Received packet from untrusted pid:%u",
addr.nl_pid);
continue;
}
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;
@ -331,12 +240,14 @@ int main(int argc, char *argv[])
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 %s",
errno, strerror(errno));
len = write(vss_fd, &error, sizeof(struct hv_vss_msg));
if (len != sizeof(struct hv_vss_msg)) {
syslog(LOG_ERR, "write failed; error: %d %s", errno,
strerror(errno));
exit(EXIT_FAILURE);
}
}
close(vss_fd);
exit(0);
}