socket.c File Reference

Compatibility and utility functions for working with network sockets. More...

#include "lib/net/socket.h"
#include "lib/net/socketpair.h"
#include "lib/net/address.h"
#include "lib/cc/compat_compiler.h"
#include "lib/err/torerr.h"
#include "lib/lock/compat_mutex.h"
#include "lib/log/log.h"
#include "lib/log/util_bug.h"
#include <stddef.h>
#include <string.h>

Go to the source code of this file.

Macros
#define	mark_socket_open(s)   ((void) (s))
#define	mark_socket_closed(s)   ((void) (s))

Functions
int	network_init (void)
void	check_network_configuration (bool server_mode)
int	get_max_sockets (void)
void	set_max_sockets (int n)
static void	socket_accounting_lock (void)
static void	socket_accounting_unlock (void)
int	tor_close_socket_simple (tor_socket_t s)
int	tor_close_socket (tor_socket_t s)
tor_socket_t	tor_open_socket (int domain, int type, int protocol)
tor_socket_t	tor_connect_socket (tor_socket_t sock, const struct sockaddr *address, socklen_t address_len)
tor_socket_t	tor_open_socket_nonblocking (int domain, int type, int protocol)
tor_socket_t	tor_open_socket_with_extensions (int domain, int type, int protocol, int cloexec, int nonblock)
void	tor_take_socket_ownership (tor_socket_t s)
void	tor_release_socket_ownership (tor_socket_t s)
tor_socket_t	tor_accept_socket (tor_socket_t sockfd, struct sockaddr *addr, socklen_t *len)
tor_socket_t	tor_accept_socket_nonblocking (tor_socket_t sockfd, struct sockaddr *addr, socklen_t *len)
tor_socket_t	tor_accept_socket_with_extensions (tor_socket_t sockfd, struct sockaddr *addr, socklen_t *len, int cloexec, int nonblock)
int	get_n_open_sockets (void)
int	tor_socketpair (int family, int type, int protocol, tor_socket_t fd[2])
int	tor_getsockname (tor_socket_t sock, struct sockaddr *address, socklen_t *address_len)
int	tor_addr_from_getsockname (struct tor_addr_t *addr_out, tor_socket_t sock)
int	set_socket_nonblocking (tor_socket_t sock)
ssize_t	read_all_from_socket (tor_socket_t sock, char *buf, size_t count)
ssize_t	write_all_to_socket (tor_socket_t fd, const char *buf, size_t count)

Variables
static int	max_sockets = 1024
static int	n_sockets_open = 0
static tor_mutex_t *	socket_accounting_mutex = NULL

Detailed Description

Compatibility and utility functions for working with network sockets.

Definition in file socket.c.

Function Documentation

check_network_configuration()

void check_network_configuration

(

bool

server_mode

)

Warn the user if any system network parameters should be changed.

Definition at line 69 of file socket.c.

get_max_sockets()

int get_max_sockets

(

void

)

Return the maximum number of allowed sockets.

Definition at line 98 of file socket.c.

Referenced by fill_socket_values(), and socket_failed_from_resource_exhaustion().

get_n_open_sockets()

int get_n_open_sockets

(

void

)

Return the number of sockets we currently have opened.

Definition at line 440 of file socket.c.

Referenced by fill_socket_values(), and tor_accept_socket_with_extensions().

network_init()

int network_init

(

void

)

Called before we make any calls to network-related functions. (Some operating systems require their network libraries to be initialized.)

Definition at line 41 of file socket.c.

read_all_from_socket()

ssize_t read_all_from_socket	(	tor_socket_t	sock,
		char *	buf,
		size_t	count
	)

Read from sock to buf, until we get count bytes or reach the end of the file. Return the number of bytes read, or -1 on error. Only use if fd is a blocking fd.

Definition at line 587 of file socket.c.

set_max_sockets()

void set_max_sockets

(

int

n

)

Set the maximum number of allowed sockets to n

Definition at line 105 of file socket.c.

set_socket_nonblocking()

int set_socket_nonblocking

(

tor_socket_t

sock

)

Turn socket into a nonblocking socket. Return 0 on success, -1 on failure.

Definition at line 560 of file socket.c.

socket_accounting_lock()

static void socket_accounting_lock ( void  )

inlinestatic

Helper: acquire the socket accounting lock.

Definition at line 130 of file socket.c.

Referenced by get_n_open_sockets(), tor_close_socket(), tor_release_socket_ownership(), and tor_take_socket_ownership().

socket_accounting_unlock()

static void socket_accounting_unlock ( void  )

inlinestatic

Helper: release the socket accounting lock.

Definition at line 139 of file socket.c.

Referenced by get_n_open_sockets().

tor_accept_socket()

tor_socket_t tor_accept_socket	(	tor_socket_t	sockfd,
		struct sockaddr *	addr,
		socklen_t *	len
	)

As accept(), but counts the number of open sockets.

Definition at line 358 of file socket.c.

tor_accept_socket_nonblocking()

tor_socket_t tor_accept_socket_nonblocking	(	tor_socket_t	sockfd,
		struct sockaddr *	addr,
		socklen_t *	len
	)

As accept(), but returns a nonblocking socket and counts the number of open sockets.

Definition at line 366 of file socket.c.

tor_accept_socket_with_extensions()

tor_socket_t tor_accept_socket_with_extensions	(	tor_socket_t	sockfd,
		struct sockaddr *	addr,
		socklen_t *	len,
		int	cloexec,
		int	nonblock
	)

As accept(), but counts the number of open sockets and handles socket creation with either of SOCK_CLOEXEC and SOCK_NONBLOCK specified. cloexec and nonblock should be either 0 or 1 to indicate if the corresponding extension should be used.

Definition at line 377 of file socket.c.

Referenced by tor_accept_socket(), and tor_accept_socket_nonblocking().

tor_addr_from_getsockname()

int tor_addr_from_getsockname	(	struct tor_addr_t *	addr_out,
		tor_socket_t	sock
	)

Find the local address associated with the socket sock, and place it in *addr_out. Return 0 on success, -1 on failure.

(As tor_getsockname, but instead places the result in a tor_addr_t.)

Definition at line 544 of file socket.c.

Referenced by client_check_address_changed().

tor_close_socket()

int tor_close_socket

(

tor_socket_t

s

)

As tor_close_socket_simple(), but keeps track of the number of open sockets. Returns 0 on success, -1 on failure.

Definition at line 217 of file socket.c.

Referenced by alert_sockets_close().

tor_close_socket_simple()

int tor_close_socket_simple

(

tor_socket_t

s

)

As close(), but guaranteed to work for sockets across platforms (including Windows, where close()ing a socket doesn't work. Returns 0 on success and the socket error code on failure.

Definition at line 148 of file socket.c.

Referenced by tor_close_socket().

tor_connect_socket()

tor_socket_t tor_connect_socket	(	tor_socket_t	sock,
		const struct sockaddr *	address,
		socklen_t	address_len
	)

Mockable wrapper for connect().

Definition at line 251 of file socket.c.

tor_getsockname()

int tor_getsockname	(	tor_socket_t	sock,
		struct sockaddr *	address,
		socklen_t *	address_len
	)

Mockable wrapper for getsockname().

Definition at line 533 of file socket.c.

Referenced by tor_addr_from_getsockname().

tor_open_socket()

tor_socket_t tor_open_socket	(	int	domain,
		int	type,
		int	protocol
	)

As socket(), but counts the number of open sockets.

Definition at line 243 of file socket.c.

Referenced by get_interface_address6_via_udp_socket_hack().

tor_open_socket_nonblocking()

tor_socket_t tor_open_socket_nonblocking	(	int	domain,
		int	type,
		int	protocol
	)

As socket(), but creates a nonblocking socket and counts the number of open sockets.

Definition at line 259 of file socket.c.

Referenced by tor_tls_release_socket().

tor_open_socket_with_extensions()

tor_socket_t tor_open_socket_with_extensions	(	int	domain,
		int	type,
		int	protocol,
		int	cloexec,
		int	nonblock
	)

As socket(), but counts the number of open sockets and handles socket creation with either of SOCK_CLOEXEC and SOCK_NONBLOCK specified. cloexec and nonblock should be either 0 or 1 to indicate if the corresponding extension should be used.

Definition at line 269 of file socket.c.

tor_release_socket_ownership()

void tor_release_socket_ownership

(

tor_socket_t

s

)

For socket accounting: declare that we are no longer the owner of the socket s. This will prevent us from overallocating sockets, and prevent us from asserting later when we close the socket s.

Definition at line 348 of file socket.c.

tor_socketpair()

int tor_socketpair	(	int	family,
		int	type,
		int	protocol,
		tor_socket_t	fd[2]
	)

Allocate a pair of connected sockets. (Like socketpair(family, type,protocol,fd), but works on systems that don't have socketpair.)

Currently, only (AF_UNIX, SOCK_STREAM, 0) sockets are supported.

Note that on systems without socketpair, this call will fail if localhost is inaccessible (for example, if the networking stack is down). And even if it succeeds, the socket pair will not be able to read while localhost is down later (the socket pair may even close, depending on OS-specific timeouts). The socket pair should work on IPv4-only, IPv6-only, and dual-stack systems, as long as they have the standard localhost addresses.

Returns 0 on success and -errno on failure; do not rely on the value of errno or WSAGetLastError().

Definition at line 469 of file socket.c.

tor_take_socket_ownership()

void tor_take_socket_ownership

(

tor_socket_t

s

)

For socket accounting: remember that we are the owner of the socket s. This will prevent us from overallocating sockets, and prevent us from asserting later when we close the socket s.

Definition at line 334 of file socket.c.

write_all_to_socket()

ssize_t write_all_to_socket	(	tor_socket_t	fd,
		const char *	buf,
		size_t	count
	)

Write count bytes from buf to sock. Return the number of bytes written, or -1 on error. Only use if fd is a blocking fd.

Definition at line 611 of file socket.c.

Variable Documentation

n_sockets_open

int n_sockets_open = 0

static

Count of number of sockets currently open. (Undercounts sockets opened by eventdns and libevent.)

Definition at line 123 of file socket.c.

Referenced by get_n_open_sockets(), tor_release_socket_ownership(), and tor_take_socket_ownership().

socket_accounting_mutex

tor_mutex_t* socket_accounting_mutex = NULL

static

Mutex to protect open_sockets, max_socket, and n_sockets_open.

Definition at line 126 of file socket.c.

Referenced by socket_accounting_unlock().