542 lines
13 KiB
C
542 lines
13 KiB
C
#if 0
|
|
|
|
/*
|
|
* IMPORTANT
|
|
*
|
|
* This file should be rewritten to avoid the use of a bitmap. Our
|
|
* buffer routines can cope with being handed blocks in an arbitrary
|
|
* order, duplicate blocks, etc. This code could be substantially
|
|
* simplified by taking advantage of these features.
|
|
*
|
|
*/
|
|
|
|
#define SLAM_PORT 10000
|
|
#define SLAM_MULTICAST_IP ((239<<24)|(255<<16)|(1<<8)|(1<<0))
|
|
#define SLAM_MULTICAST_PORT 10000
|
|
#define SLAM_LOCAL_PORT 10000
|
|
|
|
/* Set the timeout intervals to at least 1 second so
|
|
* on a 100Mbit ethernet can receive 10000 packets
|
|
* in one second.
|
|
*
|
|
* The only case that is likely to trigger all of the nodes
|
|
* firing a nack packet is a slow server. The odds of this
|
|
* happening could be reduced being slightly smarter and utilizing
|
|
* the multicast channels for nacks. But that only improves the odds
|
|
* it doesn't improve the worst case. So unless this proves to be
|
|
* a common case having the control data going unicast should increase
|
|
* the odds of the data not being dropped.
|
|
*
|
|
* When doing exponential backoff we increase just the timeout
|
|
* interval and not the base to optimize for throughput. This is only
|
|
* expected to happen when the server is down. So having some nodes
|
|
* pinging immediately should get the transmission restarted quickly after a
|
|
* server restart. The host nic won't be to baddly swamped because of
|
|
* the random distribution of the nodes.
|
|
*
|
|
*/
|
|
#define SLAM_INITIAL_MIN_TIMEOUT (TICKS_PER_SEC/3)
|
|
#define SLAM_INITIAL_TIMEOUT_INTERVAL (TICKS_PER_SEC)
|
|
#define SLAM_BASE_MIN_TIMEOUT (2*TICKS_PER_SEC)
|
|
#define SLAM_BASE_TIMEOUT_INTERVAL (4*TICKS_PER_SEC)
|
|
#define SLAM_BACKOFF_LIMIT 5
|
|
#define SLAM_MAX_RETRIES 20
|
|
|
|
/*** Packets Formats ***
|
|
* Data Packet:
|
|
* transaction
|
|
* total bytes
|
|
* block size
|
|
* packet #
|
|
* data
|
|
*
|
|
* Status Request Packet
|
|
* transaction
|
|
* total bytes
|
|
* block size
|
|
*
|
|
* Status Packet
|
|
* received packets
|
|
* requested packets
|
|
* received packets
|
|
* requested packets
|
|
* ...
|
|
* received packets
|
|
* requested packtes
|
|
* 0
|
|
*/
|
|
|
|
#define MAX_HDR (7 + 7 + 7) /* transaction, total size, block size */
|
|
#define MIN_HDR (1 + 1 + 1) /* transactino, total size, block size */
|
|
|
|
#define MAX_SLAM_REQUEST MAX_HDR
|
|
#define MIN_SLAM_REQUEST MIN_HDR
|
|
|
|
#define MIN_SLAM_DATA (MIN_HDR + 1)
|
|
|
|
static struct slam_nack {
|
|
struct iphdr ip;
|
|
struct udphdr udp;
|
|
unsigned char data[ETH_MAX_MTU -
|
|
(sizeof(struct iphdr) + sizeof(struct udphdr))];
|
|
} nack;
|
|
|
|
struct slam_state {
|
|
unsigned char hdr[MAX_HDR];
|
|
unsigned long hdr_len;
|
|
unsigned long block_size;
|
|
unsigned long total_bytes;
|
|
unsigned long total_packets;
|
|
|
|
unsigned long received_packets;
|
|
|
|
struct buffer *buffer;
|
|
unsigned char *image;
|
|
unsigned char *bitmap;
|
|
} state;
|
|
|
|
|
|
static void init_slam_state(void)
|
|
{
|
|
state.hdr_len = sizeof(state.hdr);
|
|
memset(state.hdr, 0, state.hdr_len);
|
|
state.block_size = 0;
|
|
state.total_packets = 0;
|
|
|
|
state.received_packets = 0;
|
|
|
|
state.image = 0;
|
|
state.bitmap = 0;
|
|
}
|
|
|
|
struct slam_info {
|
|
struct sockaddr_in server;
|
|
struct sockaddr_in local;
|
|
struct sockaddr_in multicast;
|
|
int sent_nack;
|
|
struct buffer *buffer;
|
|
};
|
|
|
|
#define SLAM_TIMEOUT 0
|
|
#define SLAM_REQUEST 1
|
|
#define SLAM_DATA 2
|
|
static int await_slam(int ival __unused, void *ptr,
|
|
unsigned short ptype __unused, struct iphdr *ip,
|
|
struct udphdr *udp, struct tcphdr *tcp __unused)
|
|
{
|
|
struct slam_info *info = ptr;
|
|
if (!udp) {
|
|
return 0;
|
|
}
|
|
/* I can receive two kinds of packets here, a multicast data packet,
|
|
* or a unicast request for information
|
|
*/
|
|
/* Check for a data request packet */
|
|
if ((ip->dest.s_addr == arptable[ARP_CLIENT].ipaddr.s_addr) &&
|
|
(ntohs(udp->dest) == info->local.sin_port) &&
|
|
(nic.packetlen >=
|
|
ETH_HLEN +
|
|
sizeof(struct iphdr) +
|
|
sizeof(struct udphdr) +
|
|
MIN_SLAM_REQUEST)) {
|
|
return SLAM_REQUEST;
|
|
}
|
|
/* Check for a multicast data packet */
|
|
if ((ip->dest.s_addr == info->multicast.sin_addr.s_addr) &&
|
|
(ntohs(udp->dest) == info->multicast.sin_port) &&
|
|
(nic.packetlen >=
|
|
ETH_HLEN +
|
|
sizeof(struct iphdr) +
|
|
sizeof(struct udphdr) +
|
|
MIN_SLAM_DATA)) {
|
|
return SLAM_DATA;
|
|
}
|
|
#if 0
|
|
printf("#");
|
|
printf("dest: %@ port: %d len: %d\n",
|
|
ip->dest.s_addr, ntohs(udp->dest), nic.packetlen);
|
|
#endif
|
|
return 0;
|
|
|
|
}
|
|
|
|
static int slam_encode(
|
|
unsigned char **ptr, unsigned char *end, unsigned long value)
|
|
{
|
|
unsigned char *data = *ptr;
|
|
int bytes;
|
|
bytes = sizeof(value);
|
|
while ((bytes > 0) && ((0xff & (value >> ((bytes -1)<<3))) == 0)) {
|
|
bytes--;
|
|
}
|
|
if (bytes <= 0) {
|
|
bytes = 1;
|
|
}
|
|
if (data + bytes >= end) {
|
|
return -1;
|
|
}
|
|
if ((0xe0 & (value >> ((bytes -1)<<3))) == 0) {
|
|
/* packed together */
|
|
*data = (bytes << 5) | (value >> ((bytes -1)<<3));
|
|
} else {
|
|
bytes++;
|
|
*data = (bytes << 5);
|
|
}
|
|
bytes--;
|
|
data++;
|
|
while(bytes) {
|
|
*(data++) = 0xff & (value >> ((bytes -1)<<3));
|
|
bytes--;
|
|
}
|
|
*ptr = data;
|
|
return 0;
|
|
}
|
|
|
|
static int slam_skip(unsigned char **ptr, unsigned char *end)
|
|
{
|
|
int bytes;
|
|
if (*ptr >= end) {
|
|
return -1;
|
|
}
|
|
bytes = ((**ptr) >> 5) & 7;
|
|
if (bytes == 0) {
|
|
return -1;
|
|
}
|
|
if (*ptr + bytes >= end) {
|
|
return -1;
|
|
}
|
|
(*ptr) += bytes;
|
|
return 0;
|
|
|
|
}
|
|
|
|
static unsigned long slam_decode(unsigned char **ptr, unsigned char *end,
|
|
int *err)
|
|
{
|
|
unsigned long value;
|
|
unsigned bytes;
|
|
if (*ptr >= end) {
|
|
*err = -1;
|
|
}
|
|
bytes = ((**ptr) >> 5) & 7;
|
|
if ((bytes == 0) || (bytes > sizeof(unsigned long))) {
|
|
*err = -1;
|
|
return 0;
|
|
}
|
|
if ((*ptr) + bytes >= end) {
|
|
*err = -1;
|
|
}
|
|
value = (**ptr) & 0x1f;
|
|
bytes--;
|
|
(*ptr)++;
|
|
while(bytes) {
|
|
value <<= 8;
|
|
value |= **ptr;
|
|
(*ptr)++;
|
|
bytes--;
|
|
}
|
|
return value;
|
|
}
|
|
|
|
|
|
static long slam_sleep_interval(int exp)
|
|
{
|
|
long range;
|
|
long divisor;
|
|
long interval;
|
|
range = SLAM_BASE_TIMEOUT_INTERVAL;
|
|
if (exp < 0) {
|
|
divisor = RAND_MAX/SLAM_INITIAL_TIMEOUT_INTERVAL;
|
|
} else {
|
|
if (exp > SLAM_BACKOFF_LIMIT)
|
|
exp = SLAM_BACKOFF_LIMIT;
|
|
divisor = RAND_MAX/(range << exp);
|
|
}
|
|
interval = random()/divisor;
|
|
if (exp < 0) {
|
|
interval += SLAM_INITIAL_MIN_TIMEOUT;
|
|
} else {
|
|
interval += SLAM_BASE_MIN_TIMEOUT;
|
|
}
|
|
return interval;
|
|
}
|
|
|
|
|
|
static unsigned char *reinit_slam_state(
|
|
unsigned char *header, unsigned char *end)
|
|
{
|
|
unsigned long total_bytes;
|
|
unsigned long block_size;
|
|
|
|
unsigned long bitmap_len;
|
|
unsigned long max_packet_len;
|
|
unsigned char *data;
|
|
int err;
|
|
|
|
#if 0
|
|
printf("reinit\n");
|
|
#endif
|
|
data = header;
|
|
|
|
state.hdr_len = 0;
|
|
err = slam_skip(&data, end); /* transaction id */
|
|
total_bytes = slam_decode(&data, end, &err);
|
|
block_size = slam_decode(&data, end, &err);
|
|
if (err) {
|
|
printf("ALERT: slam size out of range\n");
|
|
return 0;
|
|
}
|
|
state.block_size = block_size;
|
|
state.total_bytes = total_bytes;
|
|
state.total_packets = (total_bytes + block_size - 1)/block_size;
|
|
state.hdr_len = data - header;
|
|
state.received_packets = 0;
|
|
|
|
data = state.hdr;
|
|
slam_encode(&data, &state.hdr[sizeof(state.hdr)], state.total_packets);
|
|
max_packet_len = data - state.hdr;
|
|
memcpy(state.hdr, header, state.hdr_len);
|
|
|
|
#if 0
|
|
printf("block_size: %ld\n", block_size);
|
|
printf("total_bytes: %ld\n", total_bytes);
|
|
printf("total_packets: %ld\n", state.total_packets);
|
|
printf("hdr_len: %ld\n", state.hdr_len);
|
|
printf("max_packet_len: %ld\n", max_packet_len);
|
|
#endif
|
|
|
|
if (state.block_size > ETH_MAX_MTU - (
|
|
sizeof(struct iphdr) + sizeof(struct udphdr) +
|
|
state.hdr_len + max_packet_len)) {
|
|
printf("ALERT: slam blocksize to large\n");
|
|
return 0;
|
|
}
|
|
bitmap_len = (state.total_packets + 1 + 7)/8;
|
|
state.image = phys_to_virt ( state.buffer->addr );
|
|
/* We don't use the buffer routines properly yet; fake it */
|
|
state.buffer->fill = total_bytes;
|
|
state.bitmap = state.image + total_bytes;
|
|
if ((unsigned long)state.image < 1024*1024) {
|
|
printf("ALERT: slam filesize to large for available memory\n");
|
|
return 0;
|
|
}
|
|
memset(state.bitmap, 0, bitmap_len);
|
|
|
|
return header + state.hdr_len;
|
|
}
|
|
|
|
static int slam_recv_data(unsigned char *data)
|
|
{
|
|
unsigned long packet;
|
|
unsigned long data_len;
|
|
int err;
|
|
struct udphdr *udp;
|
|
udp = (struct udphdr *)&nic.packet[ETH_HLEN + sizeof(struct iphdr)];
|
|
err = 0;
|
|
packet = slam_decode(&data, &nic.packet[nic.packetlen], &err);
|
|
if (err || (packet > state.total_packets)) {
|
|
printf("ALERT: Invalid packet number\n");
|
|
return 0;
|
|
}
|
|
/* Compute the expected data length */
|
|
if (packet != state.total_packets -1) {
|
|
data_len = state.block_size;
|
|
} else {
|
|
data_len = state.total_bytes % state.block_size;
|
|
}
|
|
/* If the packet size is wrong drop the packet and then continue */
|
|
if (ntohs(udp->len) != (data_len + (data - (unsigned char*)udp))) {
|
|
printf("ALERT: udp packet is not the correct size\n");
|
|
return 1;
|
|
}
|
|
if (nic.packetlen < data_len + (data - nic.packet)) {
|
|
printf("ALERT: Ethernet packet shorter than data_len\n");
|
|
return 1;
|
|
}
|
|
if (data_len > state.block_size) {
|
|
data_len = state.block_size;
|
|
}
|
|
if (((state.bitmap[packet >> 3] >> (packet & 7)) & 1) == 0) {
|
|
/* Non duplicate packet */
|
|
state.bitmap[packet >> 3] |= (1 << (packet & 7));
|
|
memcpy(state.image + (packet*state.block_size), data, data_len);
|
|
state.received_packets++;
|
|
} else {
|
|
#ifdef MDEBUG
|
|
printf("<DUP>\n");
|
|
#endif
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static void transmit_nack(unsigned char *ptr, struct slam_info *info)
|
|
{
|
|
int nack_len;
|
|
/* Ensure the packet is null terminated */
|
|
*ptr++ = 0;
|
|
nack_len = ptr - (unsigned char *)&nack;
|
|
build_udp_hdr(info->server.sin_addr.s_addr, info->local.sin_port,
|
|
info->server.sin_port, 1, nack_len, &nack);
|
|
ip_transmit(nack_len, &nack);
|
|
#if defined(MDEBUG) && 0
|
|
printf("Sent NACK to %@ bytes: %d have:%ld/%ld\n",
|
|
info->server_ip, nack_len,
|
|
state.received_packets, state.total_packets);
|
|
#endif
|
|
}
|
|
|
|
static void slam_send_nack(struct slam_info *info)
|
|
{
|
|
unsigned char *ptr, *end;
|
|
/* Either I timed out or I was explicitly
|
|
* asked for a request packet
|
|
*/
|
|
ptr = &nack.data[0];
|
|
/* Reserve space for the trailling null */
|
|
end = &nack.data[sizeof(nack.data) -1];
|
|
if (!state.bitmap) {
|
|
slam_encode(&ptr, end, 0);
|
|
slam_encode(&ptr, end, 1);
|
|
}
|
|
else {
|
|
/* Walk the bitmap */
|
|
unsigned long i;
|
|
unsigned long len;
|
|
unsigned long max;
|
|
int value;
|
|
int last;
|
|
/* Compute the last bit and store an inverted trailer */
|
|
max = state.total_packets;
|
|
value = ((state.bitmap[(max -1) >> 3] >> ((max -1) & 7) ) & 1);
|
|
value = !value;
|
|
state.bitmap[max >> 3] &= ~(1 << (max & 7));
|
|
state.bitmap[max >> 3] |= value << (max & 7);
|
|
|
|
len = 0;
|
|
last = 1; /* Start with the received packets */
|
|
for(i = 0; i <= max; i++) {
|
|
value = (state.bitmap[i>>3] >> (i & 7)) & 1;
|
|
if (value == last) {
|
|
len++;
|
|
} else {
|
|
if (slam_encode(&ptr, end, len))
|
|
break;
|
|
last = value;
|
|
len = 1;
|
|
}
|
|
}
|
|
}
|
|
info->sent_nack = 1;
|
|
transmit_nack(ptr, info);
|
|
}
|
|
|
|
static void slam_send_disconnect(struct slam_info *info)
|
|
{
|
|
if (info->sent_nack) {
|
|
/* A disconnect is a packet with just the null terminator */
|
|
transmit_nack(&nack.data[0], info);
|
|
}
|
|
info->sent_nack = 0;
|
|
}
|
|
|
|
|
|
static int proto_slam(struct slam_info *info)
|
|
{
|
|
int retry;
|
|
long timeout;
|
|
|
|
init_slam_state();
|
|
state.buffer = info->buffer;
|
|
|
|
retry = -1;
|
|
rx_qdrain();
|
|
/* Arp for my server */
|
|
if (arptable[ARP_SERVER].ipaddr.s_addr != info->server.sin_addr.s_addr) {
|
|
arptable[ARP_SERVER].ipaddr.s_addr = info->server.sin_addr.s_addr;
|
|
memset(arptable[ARP_SERVER].node, 0, ETH_ALEN);
|
|
}
|
|
/* If I'm running over multicast join the multicast group */
|
|
join_group(IGMP_SERVER, info->multicast.sin_addr.s_addr);
|
|
for(;;) {
|
|
unsigned char *header;
|
|
unsigned char *data;
|
|
int type;
|
|
header = data = 0;
|
|
|
|
timeout = slam_sleep_interval(retry);
|
|
type = await_reply(await_slam, 0, info, timeout);
|
|
/* Compute the timeout for next time */
|
|
if (type == SLAM_TIMEOUT) {
|
|
/* If I timeouted recompute the next timeout */
|
|
if (retry++ > SLAM_MAX_RETRIES) {
|
|
return 0;
|
|
}
|
|
} else {
|
|
retry = 0;
|
|
}
|
|
if ((type == SLAM_DATA) || (type == SLAM_REQUEST)) {
|
|
/* Check the incomming packet and reinit the data
|
|
* structures if necessary.
|
|
*/
|
|
header = &nic.packet[ETH_HLEN +
|
|
sizeof(struct iphdr) + sizeof(struct udphdr)];
|
|
data = header + state.hdr_len;
|
|
if (memcmp(state.hdr, header, state.hdr_len) != 0) {
|
|
/* Something is fishy reset the transaction */
|
|
data = reinit_slam_state(header, &nic.packet[nic.packetlen]);
|
|
if (!data) {
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
if (type == SLAM_DATA) {
|
|
if (!slam_recv_data(data)) {
|
|
return 0;
|
|
}
|
|
if (state.received_packets == state.total_packets) {
|
|
/* We are done get out */
|
|
break;
|
|
}
|
|
}
|
|
if ((type == SLAM_TIMEOUT) || (type == SLAM_REQUEST)) {
|
|
/* Either I timed out or I was explicitly
|
|
* asked by a request packet
|
|
*/
|
|
slam_send_nack(info);
|
|
}
|
|
}
|
|
slam_send_disconnect(info);
|
|
|
|
/* Leave the multicast group */
|
|
leave_group(IGMP_SERVER);
|
|
/* FIXME don't overwrite myself */
|
|
/* load file to correct location */
|
|
return 1;
|
|
}
|
|
|
|
static int url_slam ( char *url __unused, struct sockaddr_in *server,
|
|
char *file, struct buffer *buffer ) {
|
|
struct slam_info info;
|
|
/* Set the defaults */
|
|
info.server = *server;
|
|
info.multicast.sin_addr.s_addr = htonl(SLAM_MULTICAST_IP);
|
|
info.multicast.sin_port = SLAM_MULTICAST_PORT;
|
|
info.local.sin_addr.s_addr = arptable[ARP_CLIENT].ipaddr.s_addr;
|
|
info.local.sin_port = SLAM_LOCAL_PORT;
|
|
info.buffer = buffer;
|
|
info.sent_nack = 0;
|
|
if (file[0]) {
|
|
printf("\nBad url\n");
|
|
return 0;
|
|
}
|
|
return proto_slam(&info);
|
|
}
|
|
|
|
struct protocol slam_protocol __protocol = {
|
|
.name = "x-slam",
|
|
.default_port = SLAM_PORT,
|
|
.load = url_slam,
|
|
};
|
|
|
|
#endif
|