lkml.org 
[lkml]   [2015]   [Apr]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 17/21] Tools: hv: kvp: use misc char device to communicate with kernel
Date
From: Vitaly Kuznetsov <vkuznets@redhat.com>

Use /dev/vmbus/hv_kvp 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>
---
tools/hv/hv_kvp_daemon.c | 166 +++++++++-------------------------------------
1 files changed, 31 insertions(+), 135 deletions(-)

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index 408bb07..0d9f48e 100644
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -33,7 +33,6 @@
#include <ctype.h>
#include <errno.h>
#include <arpa/inet.h>
-#include <linux/connector.h>
#include <linux/hyperv.h>
#include <linux/netlink.h>
#include <ifaddrs.h>
@@ -79,7 +78,6 @@ enum {
DNS
};

-static struct sockaddr_nl addr;
static int in_hand_shake = 1;

static char *os_name = "";
@@ -1387,34 +1385,6 @@ kvp_get_domain_name(char *buffer, int length)
freeaddrinfo(info);
}

-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"
@@ -1425,22 +1395,17 @@ void print_usage(char *argv[])

int main(int argc, char *argv[])
{
- int fd, len, nl_group;
+ int kvp_fd, len;
int error;
- struct cn_msg *message;
struct pollfd pfd;
- struct nlmsghdr *incoming_msg;
- struct cn_msg *incoming_cn_msg;
- struct hv_kvp_msg *hv_msg;
- char *p;
+ char *p;
+ struct hv_kvp_msg hv_msg[1];
char *key_value;
char *key_name;
int op;
int pool;
char *if_name;
struct hv_kvp_ipaddr_value *kvp_ip_val;
- char *kvp_recv_buffer;
- size_t kvp_recv_buffer_len;
int daemonize = 1, long_index = 0, opt;

static struct option long_options[] = {
@@ -1468,12 +1433,14 @@ int main(int argc, char *argv[])
openlog("KVP", 0, LOG_USER);
syslog(LOG_INFO, "KVP starting; pid is:%d", getpid());

- kvp_recv_buffer_len = NLMSG_LENGTH(0) + sizeof(struct cn_msg) + sizeof(struct hv_kvp_msg);
- kvp_recv_buffer = calloc(1, kvp_recv_buffer_len);
- if (!kvp_recv_buffer) {
- syslog(LOG_ERR, "Failed to allocate netlink buffer");
+ kvp_fd = open("/dev/vmbus/hv_kvp", O_RDWR);
+
+ if (kvp_fd < 0) {
+ syslog(LOG_ERR, "open /dev/vmbus/hv_kvp failed; error: %d %s",
+ errno, strerror(errno));
exit(EXIT_FAILURE);
}
+
/*
* Retrieve OS release information.
*/
@@ -1489,100 +1456,44 @@ int main(int argc, char *argv[])
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_KVP_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);
- exit(EXIT_FAILURE);
- }
-
/*
* Register ourselves with the kernel.
*/
- message = (struct cn_msg *)kvp_recv_buffer;
- message->id.idx = CN_KVP_IDX;
- message->id.val = CN_KVP_VAL;
-
- hv_msg = (struct hv_kvp_msg *)message->data;
hv_msg->kvp_hdr.operation = KVP_OP_REGISTER1;
- message->ack = 0;
- message->len = sizeof(struct hv_kvp_msg);
-
- len = netlink_send(fd, message);
- if (len < 0) {
- syslog(LOG_ERR, "netlink_send failed; error: %d %s", errno, strerror(errno));
- close(fd);
+ len = write(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));
+ if (len != sizeof(struct hv_kvp_msg)) {
+ syslog(LOG_ERR, "registration to kernel failed; error: %d %s",
+ errno, strerror(errno));
+ close(kvp_fd);
exit(EXIT_FAILURE);
}

- pfd.fd = fd;
+ pfd.fd = kvp_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(kvp_fd);
exit(EXIT_FAILURE);
}
else
continue;
}

- len = recvfrom(fd, kvp_recv_buffer, kvp_recv_buffer_len, 0,
- addr_p, &addr_l);
-
- if (len < 0) {
- int saved_errno = errno;
- syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s",
- addr.nl_pid, errno, strerror(errno));
+ len = read(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));

- if (saved_errno == ENOBUFS) {
- syslog(LOG_ERR, "receive error: ignored");
- continue;
- }
+ if (len != sizeof(struct hv_kvp_msg)) {
+ syslog(LOG_ERR, "read failed; error:%d %s",
+ errno, strerror(errno));

- close(fd);
- return -1;
+ close(kvp_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 *)kvp_recv_buffer;
-
- if (incoming_msg->nlmsg_type != NLMSG_DONE)
- continue;
-
- incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg);
- hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data;
-
/*
* We will use the KVP header information to pass back
* the error from this daemon. So, first copy the state
@@ -1603,7 +1514,7 @@ int main(int argc, char *argv[])
if (lic_version) {
strcpy(lic_version, p);
syslog(LOG_INFO, "KVP LIC Version: %s",
- lic_version);
+ lic_version);
} else {
syslog(LOG_ERR, "malloc failed");
}
@@ -1702,7 +1613,6 @@ int main(int argc, char *argv[])
goto kvp_done;
}

- hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data;
key_name = (char *)hv_msg->body.kvp_enum_data.data.key;
key_value = (char *)hv_msg->body.kvp_enum_data.data.value;

@@ -1753,31 +1663,17 @@ int main(int argc, char *argv[])
hv_msg->error = HV_S_CONT;
break;
}
- /*
- * Send the value back to the kernel. The response is
- * already in the receive buffer. Update the cn_msg header to
- * reflect the key value that has been added to the message
- */
-kvp_done:
-
- incoming_cn_msg->id.idx = CN_KVP_IDX;
- incoming_cn_msg->id.val = CN_KVP_VAL;
- incoming_cn_msg->ack = 0;
- incoming_cn_msg->len = sizeof(struct hv_kvp_msg);
-
- len = netlink_send(fd, incoming_cn_msg);
- if (len < 0) {
- int saved_errno = errno;
- syslog(LOG_ERR, "net_link send failed; error: %d %s", errno,
- strerror(errno));
-
- if (saved_errno == ENOMEM || saved_errno == ENOBUFS) {
- syslog(LOG_ERR, "send error: ignored");
- continue;
- }

+ /* Send the value back to the kernel. */
+kvp_done:
+ len = write(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));
+ if (len != sizeof(struct hv_kvp_msg)) {
+ syslog(LOG_ERR, "write failed; error: %d %s", errno,
+ strerror(errno));
exit(EXIT_FAILURE);
}
}

+ close(kvp_fd);
+ exit(0);
}
--
1.7.4.1


\
 
 \ /
  Last update: 2015-04-12 02:21    [W:0.116 / U:3.344 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site