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udpgw: another attempt at fixing binding
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ambrop7 committed Jan 1, 2012
1 parent f3e11e4 commit 59d9ed2
Showing 1 changed file with 87 additions and 25 deletions.
112 changes: 87 additions & 25 deletions udpgw/udpgw.c
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Original file line number Diff line number Diff line change
Expand Up @@ -82,6 +82,7 @@ struct connection {
BAddr addr;
const uint8_t *first_data;
int first_data_len;
btime_t last_use_time;
int closing;
BPending first_job;
BufferWriter *send_if;
Expand Down Expand Up @@ -160,6 +161,7 @@ static void client_disconnect_timer_handler (struct client *client);
static void client_connection_handler (struct client *client, int event);
static void client_decoder_handler_error (struct client *client);
static void client_recv_if_handler_send (struct client *client, uint8_t *data, int data_len);
static uint8_t * build_port_usage_array_and_find_least_used_connection (BAddr remote_addr, struct connection **out_con);
static void connection_init (struct client *client, uint16_t conid, BAddr addr, const uint8_t *data, int data_len);
static void connection_free (struct connection *con);
static void connection_logfunc (struct connection *con);
Expand Down Expand Up @@ -805,6 +807,49 @@ void client_recv_if_handler_send (struct client *client, uint8_t *data, int data
}
}

uint8_t * build_port_usage_array_and_find_least_used_connection (BAddr remote_addr, struct connection **out_con)
{
ASSERT(options.local_udp_num_ports >= 0)

// allocate port usage array
uint8_t *port_usage = BAllocSize(bsize_fromint(options.local_udp_num_ports));
if (!port_usage) {
return NULL;
}

// zero array
memset(port_usage, 0, options.local_udp_num_ports);

struct connection *least_con = NULL;

// flag inappropriate ports (those with the same remote address)
for (LinkedList1Node *ln = LinkedList1_GetFirst(&clients_list); ln; ln = LinkedList1Node_Next(ln)) {
struct client *client = UPPER_OBJECT(ln, struct client, clients_list_node);

for (LinkedList1Node *ln2 = LinkedList1_GetFirst(&client->connections_list); ln2; ln2 = LinkedList1Node_Next(ln2)) {
struct connection *con = UPPER_OBJECT(ln2, struct connection, connections_list_node);
ASSERT(con->client == client)
ASSERT(!con->closing)
ASSERT(con->local_port_index < options.local_udp_num_ports)

if (con->local_port_index < 0) {
continue;
}

if (BAddr_Compare(&con->addr, &remote_addr)) {
port_usage[con->local_port_index] = 1;

if (!least_con || con->last_use_time < least_con->last_use_time) {
least_con = con;
}
}
}
}

*out_con = least_con;
return port_usage;
}

void connection_init (struct client *client, uint16_t conid, BAddr addr, const uint8_t *data, int data_len)
{
ASSERT(client->num_connections < options.max_connections_for_client)
Expand All @@ -828,6 +873,9 @@ void connection_init (struct client *client, uint16_t conid, BAddr addr, const u
con->first_data = data;
con->first_data_len = data_len;

// set last use time
con->last_use_time = btime_gettime();

// set not closing
con->closing = 0;

Expand All @@ -854,29 +902,13 @@ void connection_init (struct client *client, uint16_t conid, BAddr addr, const u
con->local_port_index = -1;

if (options.local_udp_num_ports >= 0) {
// allocate port usage array
uint8_t *port_usage = BAllocSize(bsize_fromint(options.local_udp_num_ports));
// build port usage array, find least used connection
struct connection *least_con;
uint8_t *port_usage = build_port_usage_array_and_find_least_used_connection(addr, &least_con);
if (!port_usage) {
client_log(client, BLOG_ERROR, "BAllocSize failed");
client_log(client, BLOG_ERROR, "build_port_usage_array failed");
goto failed;
}
memset(port_usage, 0, options.local_udp_num_ports);

// flag inappropriate ports (those with the same remote address)
for (LinkedList1Node *ln = LinkedList1_GetFirst(&clients_list); ln; ln = LinkedList1Node_Next(ln)) {
struct client *client2 = UPPER_OBJECT(ln, struct client, clients_list_node);

for (LinkedList1Node *ln2 = LinkedList1_GetFirst(&client2->connections_list); ln2; ln2 = LinkedList1Node_Next(ln2)) {
struct connection *con2 = UPPER_OBJECT(ln2, struct connection, connections_list_node);
ASSERT(con2->client == client2)
ASSERT(!con2->closing)
ASSERT(con2->local_port_index < options.local_udp_num_ports)

if (con2->local_port_index >= 0 && BAddr_Compare(&con2->addr, &con->addr)) {
port_usage[con2->local_port_index] = 1;
}
}
}

// set SO_REUSEADDR
if (!BDatagram_SetReuseAddr(&con->udp_dgram, 1)) {
Expand All @@ -891,20 +923,44 @@ void connection_init (struct client *client, uint16_t conid, BAddr addr, const u
continue;
}

BAddr addr = local_udp_addr;
BAddr_SetPort(&addr, hton16(ntoh16(BAddr_GetPort(&addr)) + (uint16_t)i));

if (BDatagram_Bind(&con->udp_dgram, addr)) {
BAddr bind_addr = local_udp_addr;
BAddr_SetPort(&bind_addr, hton16(ntoh16(BAddr_GetPort(&bind_addr)) + (uint16_t)i));
if (BDatagram_Bind(&con->udp_dgram, bind_addr)) {
// remember which port we're using
con->local_port_index = i;
goto cont;
}
}

// try closing an unused connection with the same remote addr
if (!least_con || PacketPassFairQueueFlow_IsBusy(&least_con->send_qflow)) {
goto failed;
}

ASSERT(least_con->local_port_index >= 0)
ASSERT(least_con->local_port_index < options.local_udp_num_ports)
ASSERT(BAddr_Compare(&least_con->addr, &addr))

int i = least_con->local_port_index;

BLog(BLOG_INFO, "closing connection for its remote address");

// close the offending connection
connection_close(least_con);

// try binding to its port
BAddr bind_addr = local_udp_addr;
BAddr_SetPort(&bind_addr, hton16(ntoh16(BAddr_GetPort(&bind_addr)) + (uint16_t)i));
if (BDatagram_Bind(&con->udp_dgram, bind_addr)) {
// remember which port we're using
con->local_port_index = i;
goto cont;
}

failed:
client_log(client, BLOG_WARNING, "failed to bind to any local address; proceeding regardless");
cont:;
free(port_usage);
BFree(port_usage);
}

// set UDP dgram send address
Expand Down Expand Up @@ -1085,6 +1141,9 @@ int connection_send_to_udp (struct connection *con, const uint8_t *data, int dat

connection_log(con, BLOG_DEBUG, "from client %d bytes", data_len);

// set last use time
con->last_use_time = btime_gettime();

// move connection to front
LinkedList1_Remove(&client->connections_list, &con->connections_list_node);
LinkedList1_Append(&client->connections_list, &con->connections_list_node);
Expand Down Expand Up @@ -1173,6 +1232,9 @@ void connection_udp_recv_if_handler_send (struct connection *con, uint8_t *data,

connection_log(con, BLOG_DEBUG, "from UDP %d bytes", data_len);

// set last use time
con->last_use_time = btime_gettime();

// move connection to front
LinkedList1_Remove(&client->connections_list, &con->connections_list_node);
LinkedList1_Append(&client->connections_list, &con->connections_list_node);
Expand Down

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