[PATCH v3 18/21] Tools: hv: vss: use misc char device to communicate with kernel
Vitaly Kuznetsov
vkuznets at redhat.com
Thu Apr 9 08:38:47 UTC 2015
Use /dev/vmbus/hv_vss instead of netlink.
Signed-off-by: Vitaly Kuznetsov <vkuznets at redhat.com>
---
tools/hv/hv_vss_daemon.c | 139 +++++++++--------------------------------------
1 file changed, 25 insertions(+), 114 deletions(-)
diff --git a/tools/hv/hv_vss_daemon.c b/tools/hv/hv_vss_daemon.c
index 506dd01..36f1821 100644
--- a/tools/hv/hv_vss_daemon.c
+++ b/tools/hv/hv_vss_daemon.c
@@ -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;
-
- message->len = sizeof(struct hv_vss_msg);
+ vss_msg->vss_hdr.operation = VSS_OP_REGISTER1;
- 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 (addr.nl_pid) {
- syslog(LOG_WARNING,
- "Received packet from untrusted pid:%u",
- addr.nl_pid);
- continue;
+ if (len != sizeof(struct hv_vss_msg)) {
+ syslog(LOG_ERR, "read failed; error:%d %s",
+ errno, strerror(errno));
+ close(vss_fd);
+ return EXIT_FAILURE;
}
- 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);
}
--
1.9.3
More information about the devel
mailing list