tcp_conn_limit.c File Reference

This file helps the server discard excess TCP connections. More...

#include "config.h"
#include "util/regional.h"
#include "util/log.h"
#include "util/config_file.h"
#include "util/net_help.h"
#include "util/tcp_conn_limit.h"
#include "services/localzone.h"
#include "sldns/str2wire.h"

Functions
struct tcl_list *	tcl_list_create (void)
	Create TCP connection limit structure.
static void	tcl_list_free_node (rbnode_type *node, void *ATTR_UNUSED(arg))
void	tcl_list_delete (struct tcl_list *tcl)
	Delete TCP connection limit structure.
static struct tcl_addr *	tcl_list_insert (struct tcl_list *tcl, struct sockaddr_storage *addr, socklen_t addrlen, int net, uint32_t limit, int complain_duplicates)
	insert new address into tcl_list structure
static int	tcl_list_str_cfg (struct tcl_list *tcl, const char *str, const char *s2, int complain_duplicates)
	apply tcl_list string
static int	read_tcl_list (struct tcl_list *tcl, struct config_file *cfg)
	read tcl_list config
int	tcl_list_apply_cfg (struct tcl_list *tcl, struct config_file *cfg)
	Process TCP connection limit config.
int	tcl_new_connection (struct tcl_addr *tcl)
	Increment TCP connection count if found, provided the count was below the limit.
void	tcl_close_connection (struct tcl_addr *tcl)
	Decrement TCP connection count if found.
struct tcl_addr *	tcl_addr_lookup (struct tcl_list *tcl, struct sockaddr_storage *addr, socklen_t addrlen)
	Lookup address to see its TCP connection limit structure.
size_t	tcl_list_get_mem (struct tcl_list *tcl)
	Get memory used by TCP connection limit structure.
void	tcl_list_swap_tree (struct tcl_list *tcl, struct tcl_list *data)
	Swap internal tree with preallocated entries.

Detailed Description

This file helps the server discard excess TCP connections.

Function Documentation

tcl_list_create()

struct tcl_list * tcl_list_create

(

void

)

Create TCP connection limit structure.

Returns

new structure or NULL on error.

References tcl_list::region, regional_create(), and tcl_list_delete().

Referenced by daemon_init(), and fr_construct_from_config().

tcl_list_delete()

void tcl_list_delete

(

struct tcl_list *

tcl

)

Delete TCP connection limit structure.

Parameters

tcl	to delete.

References tcl_list::region, regional_destroy(), traverse_postorder(), and tcl_list::tree.

Referenced by daemon_delete(), daemon_init(), fr_construct_clear(), and tcl_list_create().

tcl_list_apply_cfg()

int tcl_list_apply_cfg	(	struct tcl_list *	tcl,
		struct config_file *	cfg
	)

Process TCP connection limit config.

Parameters

tcl	where to store.
cfg	config options.

Returns

0 on error.

References addr_tree_init(), addr_tree_init_parents(), read_tcl_list(), tcl_list::region, regional_free_all(), and tcl_list::tree.

Referenced by daemon_fork(), and fr_construct_from_config().

tcl_new_connection()

int tcl_new_connection

(

struct tcl_addr *

tcl

)

Increment TCP connection count if found, provided the count was below the limit.

Parameters

tcl	structure for tcl storage, or NULL.

Returns

: 0 if limit reached, 1 if tcl was NULL or limit not reached.

References tcl_addr::count, tcl_addr::limit, and tcl_addr::lock.

Referenced by comm_point_perform_accept().

tcl_close_connection()

void tcl_close_connection

(

struct tcl_addr *

tcl

)

Decrement TCP connection count if found.

Parameters

tcl	structure for tcl storage, or NULL.

References tcl_addr::count, tcl_addr::lock, and log_assert.

Referenced by comm_point_close().

tcl_addr_lookup()

struct tcl_addr * tcl_addr_lookup	(	struct tcl_list *	tcl,
		struct sockaddr_storage *	addr,
		socklen_t	addrlen
	)

Lookup address to see its TCP connection limit structure.

Parameters

tcl	structure for address storage.
addr	address to check
addrlen	length of addr.

Returns

: tcl structure from this address.

References addr_tree_lookup(), and tcl_list::tree.

Referenced by comm_point_perform_accept().

tcl_list_get_mem()

size_t tcl_list_get_mem

(

struct tcl_list *

tcl

)

Get memory used by TCP connection limit structure.

Parameters

tcl	structure for address storage.

Returns

bytes in use.

References tcl_list::region, and regional_get_mem().

Referenced by fr_printmem().

tcl_list_swap_tree()

void tcl_list_swap_tree	(	struct tcl_list *	tcl,
		struct tcl_list *	data
	)

Swap internal tree with preallocated entries.

Caller should manage tcl_addr item locks.

Parameters

tcl	the tcp connection list structure.
data	the data structure used to take elements from. This contains the old elements on return.

References regional::data, tcl_list::region, and tcl_list::tree.

Referenced by fr_reload_config().