From f5722b9bd418e29b7429bd9a43bd100599b26d4f Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Sat, 11 Apr 2015 18:07:56 -0700 Subject: [PATCH] Tools: hv: vss: use misc char device to communicate with kernel Use /dev/vmbus/hv_vss instead of netlink. Signed-off-by: Vitaly Kuznetsov Tested-by: Alex Ng Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- 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 506dd0148828..36f18211afa7 100644 --- a/tools/hv/hv_vss_daemon.c +++ b/tools/hv/hv_vss_daemon.c @@ -19,7 +19,6 @@ #include -#include #include #include #include @@ -30,21 +29,11 @@ #include #include #include -#include #include -#include #include -#include #include #include -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); } -- 2.20.1