Staging: hv: Add a user-space daemon to support key/value pair (KVP)

All guest specific data gathering is implemented in a user-mode daemon.
The kernel component of KVP passes the "key" to this daemon and
the daemon is responsible for passing back the corresponding
value. This daemon communicates with the kernel
component via a netlink channel.

Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/tools/hv_kvp_daemon.c

+/*
+ * An implementation of key value pair (KVP) functionality for Linux.
+ *
+ *
+ * Copyright (C) 2010, Novell, Inc.
+ * Author : K. Y. Srinivasan <ksrinivasan@novell.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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/poll.h>
+#include <sys/utsname.h>
+#include <linux/types.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <arpa/inet.h>
+#include <linux/connector.h>
+#include <linux/netlink.h>
+#include <sys/socket.h>
+#include <ifaddrs.h>
+#include <netdb.h>
+#include <syslog.h>
+
+/*
+ * KYS: TODO. Need to register these in the kernel.
+ *
+ * The following definitions are shared with the in-kernel component; do not
+ * change any of this without making the corresponding changes in
+ * the KVP kernel component.
+ */
+#define CN_KVP_IDX		0x9     /* MSFT KVP functionality */
+#define CN_KVP_VAL		0x1 /* This supports queries from the kernel */
+#define CN_KVP_USER_VAL		0x2 /* This supports queries from the user  */
+
+/*
+ * KVP protocol: The user mode component first registers with the
+ * the kernel component. Subsequently, the kernel component requests, data
+ * for the specified keys. In response to this message the user mode component
+ * fills in the value corresponding to the specified key. We overload the
+ * sequence field in the cn_msg header to define our KVP message types.
+ *
+ * We use this infrastructure for also supporting queries from user mode
+ * application for state that may be maintained in the KVP kernel component.
+ *
+ * XXXKYS: Have a shared header file between the user and kernel (TODO)
+ */
+
+enum kvp_op {
+	KVP_REGISTER = 0, /* Register the user mode component*/
+	KVP_KERNEL_GET, /*Kernel is requesting the value for the specified key*/
+	KVP_KERNEL_SET, /*Kernel is providing the value for the specified key*/
+	KVP_USER_GET, /*User is requesting the value for the specified key*/
+	KVP_USER_SET /*User is providing the value for the specified key*/
+};
+
+#define HV_KVP_EXCHANGE_MAX_KEY_SIZE	512
+#define HV_KVP_EXCHANGE_MAX_VALUE_SIZE	2048
+
+struct hv_ku_msg {
+	__u32	kvp_index;
+	__u8  kvp_key[HV_KVP_EXCHANGE_MAX_KEY_SIZE]; /* Key name */
+	__u8  kvp_value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE]; /* Key  value */
+};
+
+enum key_index {
+	FullyQualifiedDomainName = 0,
+	IntegrationServicesVersion, /*This key is serviced in the kernel*/
+	NetworkAddressIPv4,
+	NetworkAddressIPv6,
+	OSBuildNumber,
+	OSName,
+	OSMajorVersion,
+	OSMinorVersion,
+	OSVersion,
+	ProcessorArchitecture
+};
+
+/*
+ * End of shared definitions.
+ */
+
+static char kvp_send_buffer[4096];
+static char kvp_recv_buffer[4096];
+static struct sockaddr_nl addr;
+
+static char os_name[100];
+static char os_major[50];
+static char os_minor[50];
+static char processor_arch[50];
+static char os_build[100];
+static char *lic_version;
+
+void kvp_get_os_info(void)
+{
+	FILE	*file;
+	char	*eol;
+	struct utsname buf;
+
+	uname(&buf);
+	strcpy(os_build, buf.release);
+	strcpy(processor_arch, buf.machine);
+
+	file = fopen("/etc/SuSE-release", "r");
+	if (file != NULL)
+		goto kvp_osinfo_found;
+	file  = fopen("/etc/redhat-release", "r");
+	if (file != NULL)
+		goto kvp_osinfo_found;
+	/*
+	 * Add code for other supported platforms.
+	 */
+
+	/*
+	 * We don't have information about the os.
+	 */
+	strcpy(os_name, "Linux");
+	strcpy(os_major, "0");
+	strcpy(os_minor, "0");
+	return;
+
+kvp_osinfo_found:
+	fgets(os_name, 99, file);
+	eol = index(os_name, '\n');
+	*eol = '\0';
+	fgets(os_major, 49, file);
+	eol = index(os_major, '\n');
+	*eol = '\0';
+	fgets(os_minor, 49, file);
+	eol = index(os_minor, '\n');
+	*eol = '\0';
+	fclose(file);
+	return;
+}
+
+static int
+kvp_get_ip_address(int family, char *buffer, int length)
+{
+	struct ifaddrs *ifap;
+	struct ifaddrs *curp;
+	int ipv4_len = strlen("255.255.255.255") + 1;
+	int ipv6_len = strlen("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff")+1;
+	int offset = 0;
+	const char *str;
+	char tmp[50];
+	int error = 0;
+
+	/*
+	 * On entry into this function, the buffer is capable of holding the
+	 * maximum key value (2048 bytes).
+	 */
+
+	if (getifaddrs(&ifap)) {
+		strcpy(buffer, "getifaddrs failed\n");
+		return 1;
+	}
+
+	curp = ifap;
+	while (curp != NULL) {
+		if ((curp->ifa_addr != NULL) &&
+		   (curp->ifa_addr->sa_family == family)) {
+			if (family == AF_INET) {
+				struct sockaddr_in *addr =
+				(struct sockaddr_in *) curp->ifa_addr;
+
+				str = inet_ntop(family, &addr->sin_addr,
+						tmp, 50);
+				if (str == NULL) {
+					strcpy(buffer, "inet_ntop failed\n");
+					error = 1;
+					goto getaddr_done;
+				}
+				if (offset == 0)
+					strcpy(buffer, tmp);
+				else
+					strcat(buffer, tmp);
+				strcat(buffer, ";");
+
+				offset += strlen(str) + 1;
+				if ((length - offset) < (ipv4_len + 1))
+					goto getaddr_done;
+
+			} else {
+
+			/*
+			 * We only support AF_INET and AF_INET6
+			 * and the list of addresses is seperated by a ";".
+			 */
+				struct sockaddr_in6 *addr =
+				(struct sockaddr_in6 *) curp->ifa_addr;
+
+				str = inet_ntop(family,
+					&addr->sin6_addr.s6_addr,
+					tmp, 50);
+				if (str == NULL) {
+					strcpy(buffer, "inet_ntop failed\n");
+					error = 1;
+					goto getaddr_done;
+				}
+				if (offset == 0)
+					strcpy(buffer, tmp);
+				else
+					strcat(buffer, tmp);
+				strcat(buffer, ";");
+				offset += strlen(str) + 1;
+				if ((length - offset) < (ipv6_len + 1))
+					goto getaddr_done;
+
+			}
+
+		}
+		curp = curp->ifa_next;
+	}
+
+getaddr_done:
+	freeifaddrs(ifap);
+	return error;
+}
+
+
+static int
+kvp_get_domain_name(char *buffer, int length)
+{
+	struct addrinfo	hints, *info ;
+	gethostname(buffer, length);
+	int error = 0;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_INET; /*Get only ipv4 addrinfo. */
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags = AI_CANONNAME;
+
+	error = getaddrinfo(buffer, "http", &hints, &info);
+	if (error != 0) {
+		strcpy(buffer, "getaddrinfo failed\n");
+		error = 1;
+		goto get_domain_done;
+	}
+	strcpy(buffer, info->ai_canonname);
+get_domain_done:
+	freeaddrinfo(info);
+	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);
+}
+
+main(void)
+{
+	int fd, len, sock_opt;
+	int error;
+	struct cn_msg *message;
+	struct pollfd pfd;
+	struct nlmsghdr *incoming_msg;
+	struct cn_msg	*incoming_cn_msg;
+	char	*key_value;
+	char	*key_name;
+	int	 key_index;
+
+	daemon(1, 0);
+	openlog("KVP", 0, LOG_USER);
+	syslog(LOG_INFO, "KVP starting; pid is:%d", getpid());
+	/*
+	 * Retrieve OS release information.
+	 */
+	kvp_get_os_info();
+
+	fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
+	if (fd < 0) {
+		syslog(LOG_ERR, "netlink socket creation failed; error:%d", fd);
+		exit(-1);
+	}
+	addr.nl_family = AF_NETLINK;
+	addr.nl_pad = 0;
+	addr.nl_pid = 0;
+	addr.nl_groups = CN_KVP_IDX;
+
+
+	error = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
+	if (error < 0) {
+		syslog(LOG_ERR, "bind failed; error:%d", error);
+		close(fd);
+		exit(-1);
+	}
+	sock_opt = addr.nl_groups;
+	setsockopt(fd, 270, 1, &sock_opt, sizeof(sock_opt));
+	/*
+	 * Register ourselves with the kernel.
+	 */
+	message = (struct cn_msg *)kvp_send_buffer;
+	message->id.idx = CN_KVP_IDX;
+	message->id.val = CN_KVP_VAL;
+	message->seq = KVP_REGISTER;
+	message->ack = 0;
+	message->len = 0;
+
+	len = netlink_send(fd, message);
+	if (len < 0) {
+		syslog(LOG_ERR, "netlink_send failed; error:%d", len);
+		close(fd);
+		exit(-1);
+	}
+
+	pfd.fd = fd;
+
+	while (1) {
+		pfd.events = POLLIN;
+		pfd.revents = 0;
+		poll(&pfd, 1, -1);
+
+		len = recv(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0);
+
+		if (len < 0) {
+			syslog(LOG_ERR, "recv failed; error:%d", len);
+			close(fd);
+			return -1;
+		}
+
+		incoming_msg = (struct nlmsghdr *)kvp_recv_buffer;
+		incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg);
+
+		switch (incoming_cn_msg->seq) {
+		case KVP_REGISTER:
+			/*
+			 * Driver is registering with us; stash away the version
+			 * information.
+			 */
+			lic_version = malloc(strlen(incoming_cn_msg->data) + 1);
+			if (lic_version) {
+				strcpy(lic_version, incoming_cn_msg->data);
+				syslog(LOG_INFO, "KVP LIC Version: %s",
+					lic_version);
+			} else {
+				syslog(LOG_ERR, "malloc failed");
+			}
+			continue;
+
+		case KVP_KERNEL_GET:
+			break;
+		default:
+			continue;
+		}
+
+		key_index =
+		((struct hv_ku_msg *)incoming_cn_msg->data)->kvp_index;
+		key_name =
+		((struct hv_ku_msg *)incoming_cn_msg->data)->kvp_key;
+		key_value =
+		((struct hv_ku_msg *)incoming_cn_msg->data)->kvp_value;
+
+		switch (key_index) {
+		case FullyQualifiedDomainName:
+			kvp_get_domain_name(key_value,
+					HV_KVP_EXCHANGE_MAX_VALUE_SIZE);
+			strcpy(key_name, "FullyQualifiedDomainName");
+			break;
+		case IntegrationServicesVersion:
+			strcpy(key_name, "IntegrationServicesVersion");
+			strcpy(key_value, lic_version);
+			break;
+		case NetworkAddressIPv4:
+			kvp_get_ip_address(AF_INET, key_value,
+					HV_KVP_EXCHANGE_MAX_VALUE_SIZE);
+			strcpy(key_name, "NetworkAddressIPv4");
+			break;
+		case NetworkAddressIPv6:
+			kvp_get_ip_address(AF_INET6, key_value,
+					HV_KVP_EXCHANGE_MAX_VALUE_SIZE);
+			strcpy(key_name, "NetworkAddressIPv6");
+			break;
+		case OSBuildNumber:
+			strcpy(key_value, os_build);
+			strcpy(key_name, "OSBuildNumber");
+			break;
+		case OSName:
+			strcpy(key_value, os_name);
+			strcpy(key_name, "OSName");
+			break;
+		case OSMajorVersion:
+			strcpy(key_value, os_major);
+			strcpy(key_name, "OSMajorVersion");
+			break;
+		case OSMinorVersion:
+			strcpy(key_value, os_minor);
+			strcpy(key_name, "OSMinorVersion");
+			break;
+		case OSVersion:
+			strcpy(key_value, os_build);
+			strcpy(key_name, "OSVersion");
+			break;
+		case ProcessorArchitecture:
+			strcpy(key_value, processor_arch);
+			strcpy(key_name, "ProcessorArchitecture");
+			break;
+		default:
+			strcpy(key_value, "Unknown Key");
+			/*
+			 * We use a null key name to terminate enumeration.
+			 */
+			strcpy(key_name, "");
+			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
+		 */
+
+		incoming_cn_msg->id.idx = CN_KVP_IDX;
+		incoming_cn_msg->id.val = CN_KVP_VAL;
+		incoming_cn_msg->seq = KVP_USER_SET;
+		incoming_cn_msg->ack = 0;
+		incoming_cn_msg->len = sizeof(struct hv_ku_msg);
+
+		len = netlink_send(fd, incoming_cn_msg);
+		if (len < 0) {
+			syslog(LOG_ERR, "net_link send failed; error:%d", len);
+			exit(-1);
+		}
+	}
+
+}