/*
* This file is part of the Distributed Network Block Device 3
*
* Copyright(c) 2011-2012 Johann Latocha <johann@latocha.de>
*
* This file may be licensed under the terms of of the
* GNU General Public License Version 2 (the ``GPL'').
*
* Software distributed under the License is distributed
* on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
* express or implied. See the GPL for the specific language
* governing rights and limitations.
*
* You should have received a copy of the GPL along with this
* program. If not, go to http://www.gnu.org/licenses/gpl.html
* or write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include <fcntl.h>
#include <sys/sendfile.h>
#include <sys/types.h>
#include "sockhelper.h"
#include "helper.h"
#include "server.h"
#include "image.h"
#include "uplink.h"
#include "memlog.h"
#include "../serialize.h"
#include "../config.h"
static inline char recv_request_header(int sock, dnbd3_request_t *request)
{
int ret;
// Read request header from socket
if ( (ret = recv( sock, request, sizeof(*request), MSG_WAITALL )) != sizeof(*request) ) {
if ( ret == 0 ) return 0;
printf( "[DEBUG] Error receiving request: Could not read message header (%d/%d)\n", ret, (int)sizeof(*request) );
return 0;
}
// Make sure all bytes are in the right order (endianness)
fixup_request( *request );
if ( request->magic != dnbd3_packet_magic ) {
printf( "[DEBUG] Magic in client request incorrect (cmd: %d, len: %d)\n", (int)request->cmd, (int)request->size );
return 0;
}
// Payload sanity check
if ( request->cmd != CMD_GET_BLOCK && request->size > MAX_PAYLOAD ) {
memlogf( "[WARNING] Client tries to send a packet of type %d with %d bytes payload. Dropping client.", (int)request->cmd,
(int)request->size );
return 0;
}
#ifdef _DEBUG
if (_fake_delay) usleep(_fake_delay);
#endif
return 1;
}
static inline char recv_request_payload(int sock, uint32_t size, serialized_buffer_t *payload)
{
if ( size == 0 ) {
memlogf( "[BUG] Called recv_request_payload() to receive 0 bytes" );
return 0;
}
if ( size > MAX_PAYLOAD ) {
memlogf( "[BUG] Called recv_request_payload() for more bytes than the passed buffer could hold!" );
return 0;
}
if ( recv( sock, payload->buffer, size, MSG_WAITALL ) != size ) {
printf( "[ERROR] Could not receive request payload of length %d\n", (int)size );
return 0;
}
// Prepare payload buffer for reading
serializer_reset_read( payload, size );
return 1;
}
static inline char send_reply(int sock, dnbd3_reply_t *reply, void *payload)
{
const unsigned int size = reply->size;
fixup_reply( *reply );
if ( !payload || size == 0 ) {
if ( send( sock, reply, sizeof(dnbd3_reply_t), MSG_WAITALL ) != sizeof(dnbd3_reply_t) ) {
printf( "[DEBUG] Send failed (header-only)\n" );
return 0;
}
} else {
struct iovec iov[2];
iov[0].iov_base = reply;
iov[0].iov_len = sizeof(dnbd3_reply_t);
iov[1].iov_base = payload;
iov[1].iov_len = size;
if ( writev( sock, iov, 2 ) != sizeof(dnbd3_reply_t) + size ) {
printf( "[DEBUG] Send failed (reply with payload of %u bytes)\n", size );
return 0;
}
}
return 1;
}
void *net_client_handler(void *dnbd3_client)
{
dnbd3_client_t *client = (dnbd3_client_t *)(uintptr_t)dnbd3_client;
dnbd3_request_t request;
dnbd3_reply_t reply;
dnbd3_image_t *image = NULL;
int image_file = -1;
int num;
int bOk = FALSE;
serialized_buffer_t payload;
char *image_name;
uint16_t rid, client_version;
/*
char map_x, bit_mask;
uint64_t map_y;
uint64_t todo_size = 0;
uint64_t todo_offset = 0;
uint64_t cur_offset = 0;
uint64_t last_offset = 0;
*/
dnbd3_server_entry_t server_list[NUMBER_SERVERS];
// Set to zero to make valgrind happy
memset(&reply, 0, sizeof(reply));
memset(&payload, 0, sizeof(payload));
reply.magic = dnbd3_packet_magic;
// Receive first packet. This must be CMD_SELECT_IMAGE by protocol specification
if ( recv_request_header( client->sock, &request ) ) {
if ( request.cmd != CMD_SELECT_IMAGE ) {
printf( "[DEBUG] Client sent invalid handshake (%d). Dropping Client\n", (int)request.cmd );
} else {
if ( recv_request_payload( client->sock, request.size, &payload ) ) {
client_version = serializer_get_uint16( &payload );
image_name = serializer_get_string( &payload );
rid = serializer_get_uint16( &payload );
client->is_server = serializer_get_uint8( &payload );
if ( request.size < 3 || !image_name || client_version < MIN_SUPPORTED_CLIENT ) {
if ( client_version < MIN_SUPPORTED_CLIENT ) {
printf( "[DEBUG] Client too old\n" );
} else {
printf( "[DEBUG] Incomplete handshake received\n" );
}
} else {
image = image_get( image_name, rid );
if ( image == NULL ) {
printf( "[DEBUG] Client requested non-existent image '%s' (rid:%d), rejected\n", image_name, (int)rid );
} else if ( !image->working ) {
printf( "[DEBUG] Client requested non-working image '%s' (rid:%d), rejected\n", image_name, (int)rid );
} else {
image_file = open( image->path, O_RDONLY );
if ( image_file >= 0 ) {
serializer_reset_write( &payload );
serializer_put_uint16( &payload, PROTOCOL_VERSION );
serializer_put_string( &payload, image->lower_name );
serializer_put_uint16( &payload, image->rid );
serializer_put_uint64( &payload, image->filesize );
reply.cmd = CMD_SELECT_IMAGE;
reply.size = serializer_get_written_length( &payload );
if ( send_reply( client->sock, &reply, &payload ) ) {
client->image = image;
if ( !client->is_server ) image->atime = time( NULL );
bOk = TRUE;
}
}
}
}
}
}
}
// client handling mainloop
if ( bOk ) {
while ( recv_request_header( client->sock, &request ) ) {
switch ( request.cmd ) {
case CMD_GET_BLOCK:
if ( request.offset >= image->filesize ) {
// Sanity check
memlogf( "[WARNING] Client requested non-existent block" );
reply.size = 0;
reply.cmd = CMD_ERROR;
send_reply( client->sock, &reply, NULL );
break;
}
if ( request.offset + request.size > image->filesize ) {
// Sanity check
memlogf( "[WARNING] Client requested data block that extends beyond image size" );
reply.size = 0;
reply.cmd = CMD_ERROR;
send_reply( client->sock, &reply, NULL );
break;
}
if ( request.size > image->filesize ) {
// Sanity check
memlogf( "[WARNING] Client requested data block that is bigger than the image size" );
reply.size = 0;
reply.cmd = CMD_ERROR;
send_reply( client->sock, &reply, NULL );
break;
}
reply.cmd = CMD_GET_BLOCK;
reply.size = request.size;
reply.handle = request.handle;
fixup_reply( reply );
if ( send( client->sock, &reply, sizeof(dnbd3_reply_t), MSG_MORE ) != sizeof(dnbd3_reply_t) ) {
printf( "[DEBUG] Sending CMD_GET_BLOCK header failed\n" );
goto exit_client_cleanup;
}
if ( request.size == 0 ) { // Request for 0 bytes, done after sending header
send( client->sock, &reply, 0, 0 ); // Since we used MSG_MORE above...
break;
}
// no cache map means image is complete
if ( image->cache_map == NULL ) {
const ssize_t ret = sendfile( client->sock, image_file, (off_t *)&request.offset, request.size );
if ( ret != request.size ) {
printf( "[ERROR] sendfile failed (image to net %d/%d)\n", (int)ret, (int)request.size );
goto exit_client_cleanup;
}
break;
}
printf( "[DEBUG] Caching/Proxying not implemented yet!\n" );
goto exit_client_cleanup;
/*
// caching is on
dirty = 0;
todo_size = 0;
todo_offset = request.offset;
cur_offset = request.offset;
last_offset = request.offset + request.size;
// first make sure the whole requested part is in the local cache file
while(cur_offset < last_offset)
{
map_y = cur_offset >> 15; // div 32768
map_x = (cur_offset >> 12) & 7; // (X div 4096) mod 8
bit_mask = 0b00000001 << (map_x);
cur_offset += 4096;
if ((image->cache_map[map_y] & bit_mask) != 0) // cache hit
{
if (todo_size != 0) // fetch missing chunks
{
lseek(image_cache, todo_offset, SEEK_SET);
if (sendfile(image_cache, image_file, (off_t *) &todo_offset, todo_size) != todo_size)
{
if (image->file == NULL)
printf("[ERROR] Device was closed when local copy was incomplete.");
printf("[ERROR] sendfile failed (copy to cache 1)\n");
goto exit_client_cleanup;
}
todo_size = 0;
dirty = 1;
}
todo_offset = cur_offset;
}
else
{
todo_size += 4096;
}
}
// whole request was missing
if (todo_size != 0)
{
lseek(image_cache, todo_offset, SEEK_SET);
if (sendfile(image_cache, image_file, (off_t *) &todo_offset, todo_size) != todo_size)
{
printf("[ERROR] sendfile failed (copy to cache 2)\n");
goto exit_client_cleanup;
}
dirty = 1;
}
if (dirty) // cache map needs to be updated as something was missing locally
{
// set 1 in cache map for whole request
cur_offset = request.offset;
while(cur_offset < last_offset)
{
map_y = cur_offset >> 15;
map_x = (cur_offset >> 12) & 7; // mod 8
bit_mask = 0b00000001 << (map_x);
image->cache_map[map_y] |= bit_mask;
cur_offset += 4096;
}
}
// send data to client
if (sendfile(client->sock, image_cache, (off_t *) &request.offset, request.size) != request.size)
{
memlogf("[ERROR] sendfile failed (cache to net)\n");
close(client->sock);
client->sock = -1;
}
*/
break;
case CMD_GET_SERVERS:
client->is_server = FALSE; // Only clients request list of servers
// Build list of known working alt servers
num = uplink_get_matching_alt_servers( &client->host, server_list, NUMBER_SERVERS );
reply.cmd = CMD_GET_SERVERS;
reply.size = num * sizeof(dnbd3_server_entry_t);
send_reply( client->sock, &reply, server_list );
break;
case CMD_KEEPALIVE:
reply.cmd = CMD_KEEPALIVE;
reply.size = 0;
send_reply( client->sock, &reply, NULL );
break;
case CMD_SET_CLIENT_MODE:
client->is_server = FALSE;
break;
default:
memlogf( "[ERROR] Unknown command: %d", (int)request.cmd );
break;
}
// Check for messages that have been queued from another thread
while ( client->sendqueue != NULL ) {
dnbd3_binstring_t *message = NULL;
pthread_spin_lock( &client->lock );
if ( client->sendqueue != NULL ) {
message = client->sendqueue->data;
client->sendqueue = g_slist_remove( client->sendqueue, message );
}
pthread_spin_unlock( &client->lock );
send_data( client->sock, message->data, message->len );
free( message );
}
}
}
exit_client_cleanup: ;
if ( image_file != -1 ) close( image_file );
dnbd3_remove_client( client );
client = dnbd3_free_client( client );
pthread_exit( (void *)0 );
}