Tools: hv: Implement the KVP verb - KVP_OP_SET_IP_INFO

Implement the KVP verb - KVP_OP_SET_IP_INFO. This operation configures the
specified interface based on the given configuration. Since configuring
an interface is very distro specific, we invoke an external (Distro specific)
script to configure the interface.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/hyperv.h

@@ -191,6 +191,8 @@ enum hv_kvp_exchg_pool {
 #define HV_ERROR_NOT_SUPPORTED		0x80070032
 #define HV_ERROR_MACHINE_LOCKED		0x800704F7
 #define HV_ERROR_DEVICE_NOT_CONNECTED	0x8007048F
+#define HV_INVALIDARG			0x80070057
+#define HV_GUID_NOTFOUND		0x80041002
 
 #define ADDR_FAMILY_NONE	0x00
 #define ADDR_FAMILY_IPV4	0x01

tools/hv/hv_kvp_daemon.c

@@ -31,6 +31,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
+#include <ctype.h>
 #include <errno.h>
 #include <arpa/inet.h>
 #include <linux/connector.h>
@@ -41,6 +42,7 @@
 #include <syslog.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <dirent.h>
 
 /*
  * KVP protocol: The user mode component first registers with the
@@ -68,6 +70,14 @@ enum key_index {
 	ProcessorArchitecture
 };
 
+
+enum {
+	IPADDR = 0,
+	NETMASK,
+	GATEWAY,
+	DNS
+};
+
 static char kvp_send_buffer[4096];
 static char kvp_recv_buffer[4096 * 2];
 static struct sockaddr_nl addr;
@@ -81,6 +91,11 @@ static char *os_build;
 static char *lic_version = "Unknown version";
 static struct utsname uts_buf;
 
+/*
+ * The location of the interface configuration file.
+ */
+
+#define KVP_CONFIG_LOC	"/var/opt/"
 
 #define MAX_FILE_NAME 100
 #define ENTRIES_PER_BLOCK 50
@@ -490,6 +505,104 @@ done:
 	return;
 }
 
+
+
+/*
+ * Retrieve an interface name corresponding to the specified guid.
+ * If there is a match, the function returns a pointer
+ * to the interface name and if not, a NULL is returned.
+ * If a match is found, the caller is responsible for
+ * freeing the memory.
+ */
+
+static char *kvp_get_if_name(char *guid)
+{
+	DIR *dir;
+	struct dirent *entry;
+	FILE    *file;
+	char    *p, *q, *x;
+	char    *if_name = NULL;
+	char    buf[256];
+	char *kvp_net_dir = "/sys/class/net/";
+	char dev_id[256];
+
+	dir = opendir(kvp_net_dir);
+	if (dir == NULL)
+		return NULL;
+
+	snprintf(dev_id, sizeof(dev_id), "%s", kvp_net_dir);
+	q = dev_id + strlen(kvp_net_dir);
+
+	while ((entry = readdir(dir)) != NULL) {
+		/*
+		 * Set the state for the next pass.
+		 */
+		*q = '\0';
+		strcat(dev_id, entry->d_name);
+		strcat(dev_id, "/device/device_id");
+
+		file = fopen(dev_id, "r");
+		if (file == NULL)
+			continue;
+
+		p = fgets(buf, sizeof(buf), file);
+		if (p) {
+			x = strchr(p, '\n');
+			if (x)
+				*x = '\0';
+
+			if (!strcmp(p, guid)) {
+				/*
+				 * Found the guid match; return the interface
+				 * name. The caller will free the memory.
+				 */
+				if_name = strdup(entry->d_name);
+				fclose(file);
+				break;
+			}
+		}
+		fclose(file);
+	}
+
+	closedir(dir);
+	return if_name;
+}
+
+/*
+ * Retrieve the MAC address given the interface name.
+ */
+
+static char *kvp_if_name_to_mac(char *if_name)
+{
+	FILE    *file;
+	char    *p, *x;
+	char    buf[256];
+	char addr_file[256];
+	int i;
+	char *mac_addr = NULL;
+
+	snprintf(addr_file, sizeof(addr_file), "%s%s%s", "/sys/class/net/",
+		if_name, "/address");
+
+	file = fopen(addr_file, "r");
+	if (file == NULL)
+		return NULL;
+
+	p = fgets(buf, sizeof(buf), file);
+	if (p) {
+		x = strchr(p, '\n');
+		if (x)
+			*x = '\0';
+		for (i = 0; i < strlen(p); i++)
+			p[i] = toupper(p[i]);
+		mac_addr = strdup(p);
+	}
+
+	fclose(file);
+	return mac_addr;
+}
+
+
 static void kvp_process_ipconfig_file(char *cmd,
 					char *config_buf, int len,
 					int element_size, int offset)
@@ -790,6 +903,315 @@ getaddr_done:
 }
 
 
+static int expand_ipv6(char *addr, int type)
+{
+	int ret;
+	struct in6_addr v6_addr;
+
+	ret = inet_pton(AF_INET6, addr, &v6_addr);
+
+	if (ret != 1) {
+		if (type == NETMASK)
+			return 1;
+		return 0;
+	}
+
+	sprintf(addr, "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:"
+		"%02x%02x:%02x%02x:%02x%02x",
+		(int)v6_addr.s6_addr[0], (int)v6_addr.s6_addr[1],
+		(int)v6_addr.s6_addr[2], (int)v6_addr.s6_addr[3],
+		(int)v6_addr.s6_addr[4], (int)v6_addr.s6_addr[5],
+		(int)v6_addr.s6_addr[6], (int)v6_addr.s6_addr[7],
+		(int)v6_addr.s6_addr[8], (int)v6_addr.s6_addr[9],
+		(int)v6_addr.s6_addr[10], (int)v6_addr.s6_addr[11],
+		(int)v6_addr.s6_addr[12], (int)v6_addr.s6_addr[13],
+		(int)v6_addr.s6_addr[14], (int)v6_addr.s6_addr[15]);
+
+	return 1;
+
+}
+
+static int is_ipv4(char *addr)
+{
+	int ret;
+	struct in_addr ipv4_addr;
+
+	ret = inet_pton(AF_INET, addr, &ipv4_addr);
+
+	if (ret == 1)
+		return 1;
+	return 0;
+}
+
+static int parse_ip_val_buffer(char *in_buf, int *offset,
+				char *out_buf, int out_len)
+{
+	char *x;
+	char *start;
+
+	/*
+	 * in_buf has sequence of characters that are seperated by
+	 * the character ';'. The last sequence does not have the
+	 * terminating ";" character.
+	 */
+	start = in_buf + *offset;
+
+	x = strchr(start, ';');
+	if (x)
+		*x = 0;
+	else
+		x = start + strlen(start);
+
+	if (strlen(start) != 0) {
+		int i = 0;
+		/*
+		 * Get rid of leading spaces.
+		 */
+		while (start[i] == ' ')
+			i++;
+
+		if ((x - start) <= out_len) {
+			strcpy(out_buf, (start + i));
+			*offset += (x - start) + 1;
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static int kvp_write_file(FILE *f, char *s1, char *s2, char *s3)
+{
+	int ret;
+
+	ret = fprintf(f, "%s%s%s%s\n", s1, s2, "=", s3);
+
+	if (ret < 0)
+		return HV_E_FAIL;
+
+	return 0;
+}
+
+
+static int process_ip_string(FILE *f, char *ip_string, int type)
+{
+	int error = 0;
+	char addr[INET6_ADDRSTRLEN];
+	int i = 0;
+	int j = 0;
+	char str[256];
+	char sub_str[10];
+	int offset = 0;
+
+	memset(addr, 0, sizeof(addr));
+
+	while (parse_ip_val_buffer(ip_string, &offset, addr,
+					(MAX_IP_ADDR_SIZE * 2))) {
+
+		sub_str[0] = 0;
+		if (is_ipv4(addr)) {
+			switch (type) {
+			case IPADDR:
+				snprintf(str, sizeof(str), "%s", "IPADDR");
+				break;
+			case NETMASK:
+				snprintf(str, sizeof(str), "%s", "NETMASK");
+				break;
+			case GATEWAY:
+				snprintf(str, sizeof(str), "%s", "GATEWAY");
+				break;
+			case DNS:
+				snprintf(str, sizeof(str), "%s", "DNS");
+				break;
+			}
+			if (i != 0) {
+				if (type != DNS) {
+					snprintf(sub_str, sizeof(sub_str),
+						"_%d", i++);
+				} else {
+					snprintf(sub_str, sizeof(sub_str),
+						"%d", ++i);
+				}
+			} else if (type == DNS) {
+				snprintf(sub_str, sizeof(sub_str), "%d", ++i);
+			}
+
+
+		} else if (expand_ipv6(addr, type)) {
+			switch (type) {
+			case IPADDR:
+				snprintf(str, sizeof(str), "%s", "IPV6ADDR");
+				break;
+			case NETMASK:
+				snprintf(str, sizeof(str), "%s", "IPV6NETMASK");
+				break;
+			case GATEWAY:
+				snprintf(str, sizeof(str), "%s",
+					"IPV6_DEFAULTGW");
+				break;
+			case DNS:
+				snprintf(str, sizeof(str), "%s",  "DNS");
+				break;
+			}
+			if ((j != 0) || (type == DNS)) {
+				if (type != DNS) {
+					snprintf(sub_str, sizeof(sub_str),
+						"_%d", j++);
+				} else {
+					snprintf(sub_str, sizeof(sub_str),
+						"%d", ++i);
+				}
+			} else if (type == DNS) {
+				snprintf(sub_str, sizeof(sub_str),
+					"%d", ++i);
+			}
+		} else {
+			return  HV_INVALIDARG;
+		}
+
+		error = kvp_write_file(f, str, sub_str, addr);
+		if (error)
+			return error;
+		memset(addr, 0, sizeof(addr));
+	}
+
+	return 0;
+}
+
+static int kvp_set_ip_info(char *if_name, struct hv_kvp_ipaddr_value *new_val)
+{
+	int error = 0;
+	char if_file[128];
+	FILE *file;
+	char cmd[512];
+	char *mac_addr;
+
+	/*
+	 * Set the configuration for the specified interface with
+	 * the information provided. Since there is no standard
+	 * way to configure an interface, we will have an external
+	 * script that does the job of configuring the interface and
+	 * flushing the configuration.
+	 *
+	 * The parameters passed to this external script are:
+	 * 1. A configuration file that has the specified configuration.
+	 *
+	 * We will embed the name of the interface in the configuration
+	 * file: ifcfg-ethx (where ethx is the interface name).
+	 *
+	 * The information provided here may be more than what is needed
+	 * in a given distro to configure the interface and so are free
+	 * ignore information that may not be relevant.
+	 *
+	 * Here is the format of the ip configuration file:
+	 *
+	 * HWADDR=macaddr
+	 * IF_NAME=interface name
+	 * DHCP=yes (This is optional; if yes, DHCP is configured)
+	 *
+	 * IPADDR=ipaddr1
+	 * IPADDR_1=ipaddr2
+	 * IPADDR_x=ipaddry (where y = x + 1)
+	 *
+	 * NETMASK=netmask1
+	 * NETMASK_x=netmasky (where y = x + 1)
+	 *
+	 * GATEWAY=ipaddr1
+	 * GATEWAY_x=ipaddry (where y = x + 1)
+	 *
+	 * DNSx=ipaddrx (where first DNS address is tagged as DNS1 etc)
+	 *
+	 * IPV6 addresses will be tagged as IPV6ADDR, IPV6 gateway will be
+	 * tagged as IPV6_DEFAULTGW and IPV6 NETMASK will be tagged as
+	 * IPV6NETMASK.
+	 *
+	 * The host can specify multiple ipv4 and ipv6 addresses to be
+	 * configured for the interface. Furthermore, the configuration
+	 * needs to be persistent. A subsequent GET call on the interface
+	 * is expected to return the configuration that is set via the SET
+	 * call.
+	 */
+
+	snprintf(if_file, sizeof(if_file), "%s%s%s", KVP_CONFIG_LOC,
+		"hyperv/ifcfg-", if_name);
+
+	file = fopen(if_file, "w");
+
+	if (file == NULL) {
+		syslog(LOG_ERR, "Failed to open config file");
+		return HV_E_FAIL;
+	}
+
+	/*
+	 * First write out the MAC address.
+	 */
+
+	mac_addr = kvp_if_name_to_mac(if_name);
+	if (mac_addr == NULL) {
+		error = HV_E_FAIL;
+		goto setval_error;
+	}
+
+	error = kvp_write_file(file, "HWADDR", "", mac_addr);
+	if (error)
+		goto setval_error;
+
+	error = kvp_write_file(file, "IF_NAME", "", if_name);
+	if (error)
+		goto setval_error;
+
+	if (new_val->dhcp_enabled) {
+		error = kvp_write_file(file, "DHCP", "", "yes");
+		if (error)
+			goto setval_error;
+
+		/*
+		 * We are done!.
+		 */
+		goto setval_done;
+	}
+
+	/*
+	 * Write the configuration for ipaddress, netmask, gateway and
+	 * name servers.
+	 */
+
+	error = process_ip_string(file, (char *)new_val->ip_addr, IPADDR);
+	if (error)
+		goto setval_error;
+
+	error = process_ip_string(file, (char *)new_val->sub_net, NETMASK);
+	if (error)
+		goto setval_error;
+
+	error = process_ip_string(file, (char *)new_val->gate_way, GATEWAY);
+	if (error)
+		goto setval_error;
+
+	error = process_ip_string(file, (char *)new_val->dns_addr, DNS);
+	if (error)
+		goto setval_error;
+
+setval_done:
+	free(mac_addr);
+	fclose(file);
+
+	/*
+	 * Now that we have populated the configuration file,
+	 * invoke the external script to do its magic.
+	 */
+
+	snprintf(cmd, sizeof(cmd), "%s %s", "hv_set_ifconfig", if_file);
+	system(cmd);
+	return 0;
+
+setval_error:
+	syslog(LOG_ERR, "Failed to write config file");
+	free(mac_addr);
+	fclose(file);
+	return error;
+}
+
+
 static int
 kvp_get_domain_name(char *buffer, int length)
 {
@@ -859,6 +1281,8 @@ int main(void)
 	char	*key_name;
 	int	op;
 	int	pool;
+	char	*if_name;
+	struct hv_kvp_ipaddr_value *kvp_ip_val;
 
 	daemon(1, 0);
 	openlog("KVP", 0, LOG_USER);
@@ -962,6 +1386,25 @@ int main(void)
 		}
 
 		switch (op) {
+		case KVP_OP_SET_IP_INFO:
+			kvp_ip_val = &hv_msg->body.kvp_ip_val;
+			if_name = kvp_get_if_name(
+					(char *)kvp_ip_val->adapter_id);
+			if (if_name == NULL) {
+				/*
+				 * We could not map the guid to an
+				 * interface name; return error.
+				 */
+				hv_msg->error = HV_GUID_NOTFOUND;
+				break;
+			}
+			error = kvp_set_ip_info(if_name, kvp_ip_val);
+			if (error)
+				hv_msg->error = error;
+
+			free(if_name);
+			break;
+
 		case KVP_OP_SET:
 			if (kvp_key_add_or_modify(pool,
 					hv_msg->body.kvp_set.data.key,