Implement flow control for tftp.

* grub-core/net/net.c (receive_packets): Decrease the stop to 10
	packets but stop only if stop condition is satisfied.
	(grub_net_fs_read_real): Call packets_pulled after real read. Use
	`stall' instead of `eof' as stop condition.
	* grub-core/net/http.c (parse_line): Set `stall' on EOF.
	(http_err): Likewise.
	* grub-core/net/tftp.c (ack): Replace the first argument with data
	instead of socket.
	(tftp_receive): Stall if too many packets are in wait queue.
	(tftp_packets_pulled): New function.
	(grub_tftp_protocol): Set packets_pulled.
	* include/grub/net.h (grub_net_packets): New field count.
	(grub_net_put_packet): Increment count.
	(grub_net_remove_packet): Likewise.
	(grub_net_app_protocol): New field `packets_pulled'.
	(grub_net): New field `stall'.
This commit is contained in:
Vladimir 'phcoder' Serbinenko 2012-06-22 14:17:46 +02:00
parent 6b9cfac683
commit b27069e06d
5 changed files with 78 additions and 14 deletions

View file

@ -1,3 +1,24 @@
2012-06-22 Vladimir Serbinenko <phcoder@gmail.com>
Implement flow control for tftp.
* grub-core/net/net.c (receive_packets): Decrease the stop to 10
packets but stop only if stop condition is satisfied.
(grub_net_fs_read_real): Call packets_pulled after real read. Use
`stall' instead of `eof' as stop condition.
* grub-core/net/http.c (parse_line): Set `stall' on EOF.
(http_err): Likewise.
* grub-core/net/tftp.c (ack): Replace the first argument with data
instead of socket.
(tftp_receive): Stall if too many packets are in wait queue.
(tftp_packets_pulled): New function.
(grub_tftp_protocol): Set packets_pulled.
* include/grub/net.h (grub_net_packets): New field count.
(grub_net_put_packet): Increment count.
(grub_net_remove_packet): Likewise.
(grub_net_app_protocol): New field `packets_pulled'.
(grub_net): New field `stall'.
2012-06-22 Vladimir Serbinenko <phcoder@gmail.com>
* grub-core/net/net.c (receive_packets): Stop after 100 packets to let

View file

@ -82,6 +82,7 @@ parse_line (grub_file_t file, http_data_t data, char *ptr, grub_size_t len)
if (data->chunk_rem == 0)
{
file->device->net->eof = 1;
file->device->net->stall = 1;
if (file->size == GRUB_FILE_SIZE_UNKNOWN)
file->size = have_ahead (file);
}
@ -156,6 +157,7 @@ http_err (grub_net_tcp_socket_t sock __attribute__ ((unused)),
grub_free (data->current_line);
grub_free (data);
file->device->net->eof = 1;
file->device->net->stall = 1;
if (file->size == GRUB_FILE_SIZE_UNKNOWN)
file->size = have_ahead (file);
}

View file

@ -1309,7 +1309,7 @@ grub_net_fs_close (grub_file_t file)
}
static void
receive_packets (struct grub_net_card *card)
receive_packets (struct grub_net_card *card, int *stop_condition)
{
int received = 0;
if (card->num_ifaces == 0)
@ -1332,7 +1332,7 @@ receive_packets (struct grub_net_card *card)
and just mark them as used and not used. */
struct grub_net_buff *nb;
if (received > 100)
if (received > 10 && stop_condition && *stop_condition)
break;
nb = card->driver->recv (card);
@ -1362,7 +1362,7 @@ grub_net_poll_cards (unsigned time, int *stop_condition)
while ((grub_get_time_ms () - start_time) < time
&& (!stop_condition || !*stop_condition))
FOR_NET_CARDS (card)
receive_packets (card);
receive_packets (card, stop_condition);
grub_net_tcp_retransmit ();
}
@ -1376,7 +1376,7 @@ grub_net_poll_cards_idle_real (void)
if (ctime < card->last_poll
|| ctime >= card->last_poll + card->idle_poll_delay_ms)
receive_packets (card);
receive_packets (card, 0);
}
grub_net_tcp_retransmit ();
}
@ -1417,12 +1417,19 @@ grub_net_fs_read_real (grub_file_t file, char *buf, grub_size_t len)
nb->data += amount;
if (!len)
{
if (net->protocol->packets_pulled)
net->protocol->packets_pulled (file);
return total;
}
}
if (net->protocol->packets_pulled)
net->protocol->packets_pulled (file);
if (!net->eof)
{
try++;
grub_net_poll_cards (GRUB_NET_INTERVAL, &net->eof);
grub_net_poll_cards (GRUB_NET_INTERVAL, &net->stall);
}
else
return total;

View file

@ -102,6 +102,7 @@ typedef struct tftp_data
grub_uint64_t file_size;
grub_uint64_t block;
grub_uint32_t block_size;
grub_uint32_t ack_sent;
int have_oack;
struct grub_error_saved save_err;
grub_net_udp_socket_t sock;
@ -124,7 +125,7 @@ cmp (const void *a__, const void *b__)
}
static grub_err_t
ack (grub_net_udp_socket_t sock, grub_uint16_t block)
ack (tftp_data_t data, grub_uint16_t block)
{
struct tftphdr *tftph_ack;
grub_uint8_t nbdata[512];
@ -144,8 +145,11 @@ ack (grub_net_udp_socket_t sock, grub_uint16_t block)
tftph_ack->opcode = grub_cpu_to_be16 (TFTP_ACK);
tftph_ack->u.ack.block = block;
err = grub_net_send_udp_packet (sock, &nb_ack);
err = grub_net_send_udp_packet (data->sock, &nb_ack);
if (err)
return err;
data->ack_sent = block;
return GRUB_ERR_NONE;
}
static grub_err_t
@ -185,7 +189,7 @@ tftp_receive (grub_net_udp_socket_t sock __attribute__ ((unused)),
}
data->block = 0;
grub_netbuff_free (nb);
err = ack (data->sock, 0);
err = ack (data, 0);
grub_error_save (&data->save_err);
return GRUB_ERR_NONE;
case TFTP_DATA:
@ -195,9 +199,6 @@ tftp_receive (grub_net_udp_socket_t sock __attribute__ ((unused)),
grub_dprintf ("tftp", "TFTP packet too small\n");
return GRUB_ERR_NONE;
}
err = ack (data->sock, tftph->u.data.block);
if (err)
return err;
err = grub_priority_queue_push (data->pq, &nb);
if (err)
@ -223,6 +224,16 @@ tftp_receive (grub_net_udp_socket_t sock __attribute__ ((unused)),
grub_priority_queue_pop (data->pq);
if (file->device->net->packs.count < 200)
err = ack (data, tftph->u.data.block);
else
{
file->device->net->stall = 1;
err = 0;
}
if (err)
return err;
err = grub_netbuff_pull (nb_top, sizeof (tftph->opcode) +
sizeof (tftph->u.data.block));
if (err)
@ -233,6 +244,7 @@ tftp_receive (grub_net_udp_socket_t sock __attribute__ ((unused)),
if (size < data->block_size)
{
file->device->net->eof = 1;
file->device->net->stall = 1;
grub_net_udp_close (data->sock);
data->sock = NULL;
}
@ -435,11 +447,26 @@ tftp_close (struct grub_file *file)
return GRUB_ERR_NONE;
}
static grub_err_t
tftp_packets_pulled (struct grub_file *file)
{
tftp_data_t data = file->data;
if (file->device->net->packs.count >= 200)
return 0;
if (!file->device->net->eof)
file->device->net->stall = 0;
if (data->ack_sent >= data->block)
return 0;
return ack (data, data->block);
}
static struct grub_net_app_protocol grub_tftp_protocol =
{
.name = "tftp",
.open = tftp_open,
.close = tftp_close
.close = tftp_close,
.packets_pulled = tftp_packets_pulled
};
GRUB_MOD_INIT (tftp)

View file

@ -93,6 +93,7 @@ typedef struct grub_net_packets
{
grub_net_packet_t *first;
grub_net_packet_t *last;
grub_size_t count;
} grub_net_packets_t;
#ifdef GRUB_MACHINE_EFI
@ -204,12 +205,16 @@ grub_net_put_packet (grub_net_packets_t *pkts, struct grub_net_buff *nb)
else
pkts->first = pkts->last = n;
pkts->count++;
return GRUB_ERR_NONE;
}
static inline void
grub_net_remove_packet (grub_net_packet_t *pkt)
{
pkt->up->count--;
if (pkt->prev)
pkt->prev->next = pkt->next;
else
@ -236,6 +241,7 @@ struct grub_net_app_protocol
grub_err_t (*open) (struct grub_file *file, const char *filename);
grub_err_t (*seek) (struct grub_file *file, grub_off_t off);
grub_err_t (*close) (struct grub_file *file);
grub_err_t (*packets_pulled) (struct grub_file *file);
};
typedef struct grub_net
@ -247,6 +253,7 @@ typedef struct grub_net
grub_off_t offset;
grub_fs_t fs;
int eof;
int stall;
} *grub_net_t;
extern grub_net_t (*EXPORT_VAR (grub_net_open)) (const char *name);