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Subject[PATCH RESEND 2/3] Tools: hv: Fully support the new KVP verbs in the user level daemon
Date
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: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
---
tools/hv/hv_kvp_daemon.c | 281 +++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 280 insertions(+), 1 deletions(-)

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index a98878c..2fb9c3d 100644
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -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;
}
--
1.7.4.1


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