Commit db425334 authored by K. Y. Srinivasan's avatar K. Y. Srinivasan Committed by Greg Kroah-Hartman
Browse files

Tools: hv: Fully support the new KVP verbs in the user level daemon 



Now fully support the new KVP messages in the user level daemon. Hyper-V defines
multiple persistent pools to which the host can write/read/modify KVP tuples.
In this patch we implement a file for each specified pool, where the KVP tuples
will be stored in the guest.

Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: default avatarHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fa3d5b85

tools/hv/hv_kvp_daemon.c

+280 −1
Original line number Diff line number Diff line
@@ -39,7 +39,8 @@ 
#include <ifaddrs.h>

#include <netdb.h>

#include <syslog.h>



#include <sys/stat.h>

#include <fcntl.h>



/*

 * KVP protocol: The user mode component first registers with the
@@ -79,6 +80,250 @@ static char *os_build; 
static char *lic_version;

static struct utsname uts_buf;





#define MAX_FILE_NAME 100

#define ENTRIES_PER_BLOCK 50



struct kvp_record {

	__u8 key[HV_KVP_EXCHANGE_MAX_KEY_SIZE];

	__u8 value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE];

};



struct kvp_file_state {

	int fd;

	int num_blocks;

	struct kvp_record *records;

	int num_records;

	__u8 fname[MAX_FILE_NAME];

};



static struct kvp_file_state kvp_file_info[KVP_POOL_COUNT];



static void kvp_acquire_lock(int pool)

{

	struct flock fl = {F_WRLCK, SEEK_SET, 0, 0, 0};

	fl.l_pid = getpid();



	if (fcntl(kvp_file_info[pool].fd, F_SETLKW, &fl) == -1) {

		syslog(LOG_ERR, "Failed to acquire the lock pool: %d", pool);

		exit(-1);

	}

}



static void kvp_release_lock(int pool)

{

	struct flock fl = {F_UNLCK, SEEK_SET, 0, 0, 0};

	fl.l_pid = getpid();



	if (fcntl(kvp_file_info[pool].fd, F_SETLK, &fl) == -1) {

		perror("fcntl");

		syslog(LOG_ERR, "Failed to release the lock pool: %d", pool);

		exit(-1);

	}

}



static void kvp_update_file(int pool)

{

	FILE *filep;

	size_t bytes_written;



	/*

	 * We are going to write our in-memory registry out to

	 * disk; acquire the lock first.

	 */

	kvp_acquire_lock(pool);



	filep = fopen(kvp_file_info[pool].fname, "w");

	if (!filep) {

		kvp_release_lock(pool);

		syslog(LOG_ERR, "Failed to open file, pool: %d", pool);

		exit(-1);

	}



	bytes_written = fwrite(kvp_file_info[pool].records,

				sizeof(struct kvp_record),

				kvp_file_info[pool].num_records, filep);



	fflush(filep);

	kvp_release_lock(pool);

}



static int kvp_file_init(void)

{

	int ret, fd;

	FILE *filep;

	size_t records_read;

	__u8 *fname;

	struct kvp_record *record;

	struct kvp_record *readp;

	int num_blocks;

	int i;

	int alloc_unit = sizeof(struct kvp_record) * ENTRIES_PER_BLOCK;



	if (access("/var/opt/hyperv", F_OK)) {

		if (mkdir("/var/opt/hyperv", S_IRUSR | S_IWUSR | S_IROTH)) {

			syslog(LOG_ERR, " Failed to create /var/opt/hyperv");

			exit(-1);

		}

	}



	for (i = 0; i < KVP_POOL_COUNT; i++) {

		fname = kvp_file_info[i].fname;

		records_read = 0;

		num_blocks = 1;

		sprintf(fname, "/var/opt/hyperv/.kvp_pool_%d", i);

		fd = open(fname, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IROTH);



		if (fd == -1)

			return 1;





		filep = fopen(fname, "r");

		if (!filep)

			return 1;



		record = malloc(alloc_unit * num_blocks);

		if (record == NULL) {

			fclose(filep);

			return 1;

		}

		while (!feof(filep)) {

			readp = &record[records_read];

			records_read += fread(readp, sizeof(struct kvp_record),

					ENTRIES_PER_BLOCK,

					filep);



			if (!feof(filep)) {

				/*

				 * We have more data to read.

				 */

				num_blocks++;

				record = realloc(record, alloc_unit *

						num_blocks);

				if (record == NULL) {

					fclose(filep);

					return 1;

				}

				continue;

			}

			break;

		}

		kvp_file_info[i].fd = fd;

		kvp_file_info[i].num_blocks = num_blocks;

		kvp_file_info[i].records = record;

		kvp_file_info[i].num_records = records_read;

		fclose(filep);



	}



	return 0;

}



static int kvp_key_delete(int pool, __u8 *key, int key_size)

{

	int i;

	int j, k;

	int num_records = kvp_file_info[pool].num_records;

	struct kvp_record *record = kvp_file_info[pool].records;



	for (i = 0; i < num_records; i++) {

		if (memcmp(key, record[i].key, key_size))

			continue;

		/*

		 * Found a match; just move the remaining

		 * entries up.

		 */

		if (i == num_records) {

			kvp_file_info[pool].num_records--;

			kvp_update_file(pool);

			return 0;

		}



		j = i;

		k = j + 1;

		for (; k < num_records; k++) {

			strcpy(record[j].key, record[k].key);

			strcpy(record[j].value, record[k].value);

			j++;

		}



		kvp_file_info[pool].num_records--;

		kvp_update_file(pool);

		return 0;

	}

	return 1;

}



static int kvp_key_add_or_modify(int pool, __u8 *key, int key_size, __u8 *value,

			int value_size)

{

	int i;

	int j, k;

	int num_records = kvp_file_info[pool].num_records;

	struct kvp_record *record = kvp_file_info[pool].records;

	int num_blocks = kvp_file_info[pool].num_blocks;



	if ((key_size > HV_KVP_EXCHANGE_MAX_KEY_SIZE) ||

		(value_size > HV_KVP_EXCHANGE_MAX_VALUE_SIZE))

		return 1;



	for (i = 0; i < num_records; i++) {

		if (memcmp(key, record[i].key, key_size))

			continue;

		/*

		 * Found a match; just update the value -

		 * this is the modify case.

		 */

		memcpy(record[i].value, value, value_size);

		kvp_update_file(pool);

		return 0;

	}



	/*

	 * Need to add a new entry;

	 */

	if (num_records == (ENTRIES_PER_BLOCK * num_blocks)) {

		/* Need to allocate a larger array for reg entries. */

		record = realloc(record, sizeof(struct kvp_record) *

			 ENTRIES_PER_BLOCK * (num_blocks + 1));



		if (record == NULL)

			return 1;

		kvp_file_info[pool].num_blocks++;



	}

	memcpy(record[i].value, value, value_size);

	memcpy(record[i].key, key, key_size);

	kvp_file_info[pool].records = record;

	kvp_file_info[pool].num_records++;

	kvp_update_file(pool);

	return 0;

}



static int kvp_get_value(int pool, __u8 *key, int key_size, __u8 *value,

			int value_size)

{

	int i;

	int num_records = kvp_file_info[pool].num_records;

	struct kvp_record *record = kvp_file_info[pool].records;



	if ((key_size > HV_KVP_EXCHANGE_MAX_KEY_SIZE) ||

		(value_size > HV_KVP_EXCHANGE_MAX_VALUE_SIZE))

		return 1;



	for (i = 0; i < num_records; i++) {

		if (memcmp(key, record[i].key, key_size))

			continue;

		/*

		 * Found a match; just copy the value out.

		 */

		memcpy(value, record[i].value, value_size);

		return 0;

	}



	return 1;

}



void kvp_get_os_info(void)

{

	FILE	*file;
@@ -315,6 +560,11 @@ int main(void) 
	 */

	kvp_get_os_info();



	if (kvp_file_init()) {

		syslog(LOG_ERR, "Failed to initialize the pools");

		exit(-1);

	}



	fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);

	if (fd < 0) {

		syslog(LOG_ERR, "netlink socket creation failed; error:%d", fd);
@@ -389,9 +639,38 @@ int main(void) 
			}

			continue;



		/*

		 * The current protocol with the kernel component uses a

		 * NULL key name to pass an error condition.

		 * For the SET, GET and DELETE operations,

		 * use the existing protocol to pass back error.

		 */



		case KVP_OP_SET:

			if (kvp_key_add_or_modify(hv_msg->kvp_hdr.pool,

					hv_msg->body.kvp_set.data.key,

					hv_msg->body.kvp_set.data.key_size,

					hv_msg->body.kvp_set.data.value,

					hv_msg->body.kvp_set.data.value_size))

				strcpy(hv_msg->body.kvp_set.data.key, "");

			break;



		case KVP_OP_GET:

			if (kvp_get_value(hv_msg->kvp_hdr.pool,

					hv_msg->body.kvp_set.data.key,

					hv_msg->body.kvp_set.data.key_size,

					hv_msg->body.kvp_set.data.value,

					hv_msg->body.kvp_set.data.value_size))

				strcpy(hv_msg->body.kvp_set.data.key, "");

			break;



		case KVP_OP_DELETE:

			if (kvp_key_delete(hv_msg->kvp_hdr.pool,

					hv_msg->body.kvp_delete.key,

					hv_msg->body.kvp_delete.key_size))

				strcpy(hv_msg->body.kvp_delete.key, "");

			break;



		default:

			break;

		}

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