#include "job.h"
#include "saveload.h"
#include "memlog.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <glib/gslist.h>
#include <libxml/parser.h>
#include <libxml/xpath.h>
#include "xmlutil.h"
#define DEV_STRLEN 12 // INCLUDING NULLCHAR (increase to 13 if you need more than 100 (0-99) devices)
#define MAX_NUM_DEVICES_TO_CHECK 100
#ifndef FALSE
#define FALSE (0)
#endif
#ifndef TRUE
#define TRUE (!FALSE)
#endif
typedef struct
{
char available;
char name[DEV_STRLEN];
} device_t;
// "/dev/dnbdXX" == 11 bytes per device + nullchar = 12
static device_t *devices = NULL;
static int num_devices = 0;
static char keep_running = TRUE;
// Private functions
static char *get_free_device();
static void query_servers();
static void update_image_atimes(time_t now);
//
void *dnbd3_job_thread(void *data)
{
int i, j;
// Determine number of available dnbd3 devices, which are needed for proxy mode
char dev[DEV_STRLEN];
for (i = 0; i < MAX_NUM_DEVICES_TO_CHECK; ++i)
{
snprintf(dev, DEV_STRLEN, "/dev/dnbd%d", i);
if (access(dev, W_OK | R_OK)) // Need RW access to device to read and do ioctl
continue;
++num_devices;
}
if (num_devices > 0)
{
devices = calloc(num_devices, sizeof(*devices));
for (i = 0, j = 0; i < MAX_NUM_DEVICES_TO_CHECK; ++i)
{
memset(dev, 0, DEV_STRLEN);
snprintf(dev, DEV_STRLEN, "/dev/dnbd%d", i);
if (access(dev, W_OK | R_OK))
continue;
if (j >= num_devices) // More available devices during second iteration? :-(
break;
memcpy(devices[j].name, dev, DEV_STRLEN);
devices[j].available = TRUE;
++j;
}
}
//
time_t next_delete_invocation = 0;
//
// Job/Watchdog mainloop
while (keep_running)
{
const time_t starttime = time(NULL);
//
// Update image atime
update_image_atimes(starttime);
// Call image deletion function if last call is more than 5 minutes ago
if (starttime < next_delete_invocation)
{
next_delete_invocation = starttime + 300;
dnbd3_exec_delete(TRUE);
}
// TODO: Replicate proxied images (limited bandwidth)
// Query other servers for new images/status/...
query_servers();
// TODO: Switch server of dnbd device based on more sophisticated inputs than just rtt
// Calc sleep timeout for next iteration
sleep(30 - (time(NULL) - starttime)); // Sleep 30 seconds, but account for the time it took to execute the loop
}
//
free(devices);
devices = NULL;
pthread_exit(NULL);
return NULL;
}
void dnbd3_job_shutdown()
{
keep_running = FALSE;
}
static void update_image_atimes(time_t now)
{
GSList *iterator;
pthread_spin_lock(&_spinlock);
for (iterator = _dnbd3_clients; iterator; iterator = iterator->next)
{
dnbd3_client_t *client = iterator->data;
if (client && client->image && !client->is_server)
client->image->atime = now;
}
pthread_spin_unlock(&_spinlock);
}
static void query_servers()
{
if (_trusted_servers == NULL)
return;
struct timeval client_timeout, connect_timeout;
client_timeout.tv_sec = 0;
client_timeout.tv_usec = 500 * 1000;
connect_timeout.tv_sec = 2;
connect_timeout.tv_usec = 0;
int client_sock, num;
dnbd3_trusted_server_t *server;
dnbd3_host_t host;
struct sockaddr_in addr4;
for (num = 0;; ++num)
{
// "Iterate" this way to prevent holding the lock for a long time, although it is possible to skip a server this way...
pthread_spin_lock(&_spinlock);
server = g_slist_nth_data(_trusted_servers, num);
if (server == NULL)
{
pthread_spin_unlock(&_spinlock);
break; // Done
}
memcpy(&host, &server->host, sizeof(host));
pthread_spin_unlock(&_spinlock);
// Connect
if (host.type != AF_INET)
{
printf("[DEBUG] Unsupported addr type '%d', ignoring trusted server.\n", (int)host.type);
continue;
}
// Create socket (Extend for IPv6)
if ((client_sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
{
printf("[DEBUG] Error creating server-to-server socket.\n");
continue;
}
// Set host (IPv4)
memset(&addr4, 0, sizeof(addr4));
addr4.sin_family = AF_INET;
memcpy(&addr4.sin_addr.s_addr, host.addr, 4);
addr4.sin_port = host.port;
// Connect to server
setsockopt(client_sock, SOL_SOCKET, SO_RCVTIMEO, &connect_timeout, sizeof(connect_timeout));
setsockopt(client_sock, SOL_SOCKET, SO_SNDTIMEO, &connect_timeout, sizeof(connect_timeout));
if (connect(client_sock, (struct sockaddr *)&addr4, sizeof(addr4)) < 0)
{
printf("[DEBUG] Could not connect to other server...\n");
close(client_sock); // TODO: Remove from alt server list if failed too often
continue;
}
// Apply read/write timeout
setsockopt(client_sock, SOL_SOCKET, SO_RCVTIMEO, &client_timeout, sizeof(client_timeout));
setsockopt(client_sock, SOL_SOCKET, SO_SNDTIMEO, &client_timeout, sizeof(client_timeout));
//
// TODO: Send and receive info from server
//
close(client_sock);
//
// TODO: Process data, update server info, add/remove this server as alt server for images, replicate images, etc.
}
}
/**
* Get full name of an available dnbd3 device, eg. /dev/dnbd4
* Returned buffer is owned by this module, do not modify or free!
* Returns NULL if all devices are in use
*/
static char *get_free_device()
{
if (devices == NULL)
return NULL;
int i, c;
char buffer[100];
for (i = 0; i < num_devices; ++i)
{
if (!devices[i].available)
continue;
devices[i].available = FALSE;
// Check sysfs if device is maybe already connected
snprintf(buffer, 100, "/sys/devices/virtual/block/%s/net/cur_server_addr", devices[i].name + 5);
FILE *f = fopen(buffer, "r");
if (f == NULL)
{
printf("[DEBUG] Could not open %s - device marked as used.\n", buffer);
continue;
}
c = fgetc(f);
fclose(f);
if (c > 0)
{
// Could read something, so the device is connected
printf("[DEBUG] Free device %s is actually in use - marked as such.\n", devices[i].name);
continue;
}
return devices[i].name;
}
memlogf("[WARNING] No more free dnbd3 devices - proxy mode probably affected.");
return NULL;
}
