exported symbols from net.c More...

Macros
#define	SOL_DCCP 269
	Linux socket level. More...

#define	MAX_HOSTLEN 256
	The maximum length of the host component in an URL. More...

#define	BACKLOG 10
	Functions to support listening sockets. More...

#define	DCCP_MAX_HOST_CCIDS 20
	Functions and definitions to support `IPPROTO_DCCP`. More...

Functions
struct flowopts *	flowopt_new (void)
	Allocate and initialize a flowopt queue. More...

void	flowopt_add (struct flowopts fo, int level, int opt, const char name, const void *val, int len)
	Append new socket option to flowopt queue. More...

void	flowopt_cleanup (struct flowopts *fo)
	Deallocate all resources of a flowopts structure. More...

char *	parse_cidr (const char cidr, char addr, ssize_t addrlen, int32_t *netmask)
	Functions to parse and validate (parts of) URLs. More...

char *	parse_url (const char url, char host, ssize_t hostlen, int32_t *port)
	Parse and validate URL string. More...

__malloc char *	format_url (const char *url, int default_port)
	Pretty-print a host/port pair. More...

const char *	stringify_port (int port, const char *transport)
	Stringify port number, resolve into service name where defined. More...

int	lookup_address (unsigned l4type, bool passive, const char host, int port_number, struct addrinfo *result)
	Resolve an IPv4/IPv6 address. More...

int	makesock (unsigned l4type, bool passive, const char host, uint16_t port_number, struct flowopts fo)
	Generic socket creation (passive and active sockets). More...

int	makesock_addrinfo (unsigned l4type, bool passive, struct addrinfo ai, struct flowopts fo)
	Create an active or passive socket. More...

void	extract_v4_addr (const struct sockaddr_storage ss, struct in_addr ia)
	Extract IPv4 or IPv6-mapped-IPv4 address from sockaddr_storage. More...

bool	sockaddr_equal (const struct sockaddr sa1, const struct sockaddr sa2)
	Compare the address part of IPv4/6 addresses. More...

int	para_listen (unsigned l4type, const char *addr, uint16_t port)
	Create a passive / listening socket. More...

int	para_listen_simple (unsigned l4type, uint16_t port)
	Create a socket which listens on all network addresses. More...

char *	remote_name (int sockfd)
	Pretty-printing of IPv4/6 socket addresses. More...

int	generic_max_transport_msg_size (int sockfd)
	Determining maximum payload (packet) size. More...

int	recv_bin_buffer (int fd, char *buf, size_t size)
	Receive data from a file descriptor. More...

int	recv_buffer (int fd, char *buf, size_t size)
	Receive and write terminating NULL byte. More...

int	para_accept (int fd, void addr, socklen_t size, int new_fd)
	Wrapper around the accept system call. More...

int	create_local_socket (const char *name)
	Create a socket for local communication and listen on it. More...

int	connect_local_socket (const char *name)
	Prepare, create, and connect to a Unix domain socket for local communication. More...

int	recv_cred_buffer (int, char *, size_t)
	Receive a buffer and the Unix credentials of the sending process. More...

ssize_t	send_cred_buffer (int, char *)
	Send a buffer and the credentials of the current process to a socket. More...

int	dccp_available_ccids (uint8_t **ccid_array)
	Probe the list of DCCP CCIDs configured on this host. More...

Detailed Description

exported symbols from net.c

Macro Definition Documentation

◆ SOL_DCCP

#define SOL_DCCP 269

Linux socket level.

◆ MAX_HOSTLEN

#define MAX_HOSTLEN 256

The maximum length of the host component in an URL.

◆ BACKLOG

#define BACKLOG 10

Functions to support listening sockets.

How many pending connections queue of a listening server will hold.

◆ DCCP_MAX_HOST_CCIDS

#define DCCP_MAX_HOST_CCIDS 20

Functions and definitions to support IPPROTO_DCCP.

Hardcoded maximum number of separate CCID modules compiled into a host.

Function Documentation

◆ flowopt_new()

struct flowopts* flowopt_new ( void )

Allocate and initialize a flowopt queue.

Returns: A new structure to be passed to flowopt_add(). It is automatically deallocated in makesock().

References alloc().

◆ flowopt_add()

void flowopt_add	(	struct flowopts *	fo,
		int	lev,
		int	opt,
		const char *	name,
		const void *	val,
		int	len
	)

Append new socket option to flowopt queue.

Parameters

fo	The flowopt queue to append to.
lev	Level at which opt resides.
opt	New option to add.
name	Stringified name of opt.
val	The value to set opt to.
len	Length of val.

See also: setsockopt(2).

References alloc(), and para_strdup().

◆ flowopt_cleanup()

void flowopt_cleanup ( struct flowopts * fo )

Deallocate all resources of a flowopts structure.

Parameters

fo	A pointer as returned from flowopt_new().

It's OK to pass NULL here in which case the function does nothing.

References list_for_each_entry_safe.

◆ parse_cidr()

char* parse_cidr	(	const char *	cidr,
		char *	addr,
		ssize_t	addrlen,
		int32_t *	netmask
	)

Functions to parse and validate (parts of) URLs.

Parameters

cidr	Address in CIDR notation
addr	Copy of the IPv4 address part of cidr
addrlen	Size of addr in bytes
netmask	Value of the netmask part in cidr or the default of 32 if not specified.

Returns: Pointer to addr if successful, NULL on error.

See also: RFC 4632.

References para_atoi32().

◆ parse_url()

char* parse_url	(	const char *	url,
		char *	host,
		ssize_t	hostlen,
		int32_t *	port
	)

Parse and validate URL string.

The URL syntax is loosely based on RFC 3986, supporting one of

"["host"]"[:port] for native IPv6 addresses and
host[:port] for IPv4 hostnames and DNS names.

Native IPv6 addresses must be enclosed in square brackets, since otherwise there is an ambiguity with the port separator ‘:’. The 'port' part is always considered to be a number; if absent, it is set to -1, to indicate that a default port is to be used.

The following are valid examples:

10.10.1.1
10.10.1.2:8000
localhost
localhost:8001
[::1]:8000
[badc0de::1]

Parameters

url	The URL string to take apart.
host	To return the copied host part of url.
hostlen	The maximum length of host.
port	To return the port number (if any) of url.

Returns: Pointer to host, or NULL if failed. If NULL is returned, host and port are undefined. If no port number was present in url, port is set to -1.

See also: RFC 3986, 3.2.2/3.2.3.

References para_atoi32().

Referenced by format_url(), and para_listen().

◆ format_url()

__malloc char* format_url	(	const char *	url,
		int	default_port
	)

Pretty-print a host/port pair.

Parameters

url	NULL, or any string accepted by parse_url().
default_port	Applies if url has no port.

If the url argument is NULL, the function returns the string 0.0.0.0:default_port. Otherwise it calls parse_url() to check the syntax of the input string given by url. On errors the string "?" is returned. Otherwise, if url contains a port, a copy of url is returned. If no port was supplied, a colon and the default port are appended to url.

Returns: In all cases the returned string is a allocated with malloc(3) and has to be freed by the caller.

References make_message(), MAX_HOSTLEN, para_strdup(), and parse_url().

Referenced by generic_com_on(), and generic_sender_status().

◆ stringify_port()

const char* stringify_port	(	int	port,
		const char *	transport
	)

Stringify port number, resolve into service name where defined.

Parameters

port	2-byte port number, in host-byte-order.
transport	Transport protocol name (e.g. "udp", "tcp"), or NULL.

Returns: Pointer to static result buffer.

See also: getservbyport(3), services(5), nsswitch.conf(5).

Referenced by generic_sender_status().

◆ lookup_address()

int lookup_address	(	unsigned	l4type,
		bool	passive,
		const char *	host,
		int	port_number,
		struct addrinfo **	result
	)

Resolve an IPv4/IPv6 address.

Parameters

l4type	The layer-4 type (`IPPROTO_xxx`).
passive	Whether `AI_PASSIVE` should be included as hint.
host	Remote or local hostname or IPv/6 address string.
port_number	Used to set the port in each returned address structure.
result	addrinfo structures are returned here.

The interpretation of host depends on the value of passive. On a passive socket host is interpreted as an interface IPv4/6 address (can be left NULL). On an active socket, host is the peer DNS name or IPv4/6 address to connect to.

Returns: Standard.

See also: getaddrinfo(3).

Referenced by makesock().

◆ makesock()

int makesock	(	unsigned	l4type,
		bool	passive,
		const char *	host,
		uint16_t	port_number,
		struct flowopts *	fo
	)

Generic socket creation (passive and active sockets).

Parameters

l4type	The layer-4 type (`IPPROTO_xxx`).
passive	Whether this is a passive or active socket.
host	Passed to lookup_address().
port_number	Passed to lookup_address().
fo	Passed to makesock_addrinfo().

This creates a ready-made IPv4/v6 socket structure after looking up the necessary parameters. The function first calls lookup_address() and passes the address information to makesock_addrinfo() to create and initialize the socket.

Returns: The newly created file descriptor on success, a negative error code on failure.

See also: lookup_address(), makesock_addrinfo().

References lookup_address(), makesock_addrinfo(), and PARA_NOTICE_LOG.

Referenced by dccp_available_ccids(), and para_listen().

◆ makesock_addrinfo()

int makesock_addrinfo	(	unsigned	l4type,
		bool	passive,
		struct addrinfo *	ai,
		struct flowopts *	fo
	)

Create an active or passive socket.

Parameters

l4type	`IPPROTO_TCP`, `IPPROTO_UDP`, or `IPPROTO_DCCP`.
passive	Whether to call bind(2) or connect(2).
ai	Address information as obtained from lookup_address().
fo	Socket options to be set before making the connection.

bind(2) is called on passive sockets, and connect(2) on active sockets. The algorithm tries all possible address combinations until it succeeds. If fo is supplied, options are set but cleanup must be performed in the caller.

Returns: File descriptor on success, E_MAKESOCK on errors.

See also: lookup_address(), makesock(), ip(7), ipv6(7), bind(2), connect(2).

Referenced by makesock().

◆ extract_v4_addr()

void extract_v4_addr	(	const struct sockaddr_storage *	ss,
		struct in_addr *	ia
	)

Extract IPv4 or IPv6-mapped-IPv4 address from sockaddr_storage.

Parameters

ss	Container of IPv4/6 address.
ia	Extracted IPv4 address (different from 0) or 0 if unsuccessful.

See also: RFC 3493.

◆ sockaddr_equal()

bool sockaddr_equal	(	const struct sockaddr *	sa1,
		const struct sockaddr *	sa2
	)

Compare the address part of IPv4/6 addresses.

Parameters

sa1	First address.
sa2	Second address.

Returns: True iff the IP address of sa1 and sa2 match.

◆ para_listen()

int para_listen	(	unsigned	l4type,
		const char *	addr,
		uint16_t	port
	)

Create a passive / listening socket.

Parameters

l4type	The transport-layer type (`IPPROTO_xxx`).
addr	Passed to parse_url() if not NULL.
port	Ignored if addr contains a port number.

Returns: Positive integer (socket descriptor) on success, negative value otherwise.

See also: makesock(), ip(7), ipv6(7), bind(2), listen(2).

References BACKLOG, ERRNO_TO_PARA_ERROR, makesock(), MAX_HOSTLEN, PARA_INFO_LOG, and parse_url().

Referenced by generic_com_on(), and para_listen_simple().

◆ para_listen_simple()

int para_listen_simple	(	unsigned	l4type,
		uint16_t	port
	)

Create a socket which listens on all network addresses.

Parameters

l4type	See para_listen().
port	See para_listen().

This is a simple wrapper for para_listen() which passes a NULL pointer as the address information.

Returns: See para_listen().

References para_listen().

◆ remote_name()

char* remote_name ( int fd )

Pretty-printing of IPv4/6 socket addresses.

Parameters

fd	The socket descriptor of the connected socket.

Returns: A static character string identifying hostname and port of the chosen side in numeric host:port format.

See also: getsockname(2), getpeername(2), parse_url(), getnameinfo(3), services(5), nsswitch.conf(5).

References PARA_ERROR_LOG.

Referenced by accept_sender_client().

◆ generic_max_transport_msg_size()

int generic_max_transport_msg_size ( int sockfd )

Determining maximum payload (packet) size.

Parameters

sockfd The socket file descriptor.

The socket must be connected. See RFC 1122, 3.3.3. If the protocol family could not be determined, AF_INET is assumed.

Returns: The maximum message size of the address family type.

References PARA_ERROR_LOG.

◆ recv_bin_buffer()

int recv_bin_buffer	(	int	fd,
		char *	buf,
		size_t	size
	)

Receive data from a file descriptor.

Parameters

fd	The file descriptor.
buf	The buffer to write the data to.
size	The size of buf.

Receive at most size bytes from file descriptor fd.

Returns: The number of bytes received on success, negative on errors, zero if the peer has performed an orderly shutdown.

See also: recv(2).

References ERRNO_TO_PARA_ERROR.

Referenced by recv_buffer(), recv_sb(), and send_callback_request().

◆ recv_buffer()

int recv_buffer	(	int	fd,
		char *	buf,
		size_t	size
	)

Receive and write terminating NULL byte.

Parameters

fd	The file descriptor.
buf	The buffer to write the data to.
size	The size of buf.

Read at most size - 1 bytes from file descriptor fd and write a NULL byte at the end of the received data.

Returns: The return value of the underlying call to recv_bin_buffer().

See also: recv_bin_buffer()

References recv_bin_buffer().

◆ para_accept()

int para_accept	(	int	fd,
		void *	addr,
		socklen_t	size,
		int *	new_fd
	)

Wrapper around the accept system call.

Parameters

fd	The listening socket.
addr	Structure which is filled in with the address of the peer socket.
size	Should contain the size of the structure pointed to by addr.
new_fd	Result pointer.

Accept incoming connections on addr, retry if interrupted.

Returns: Negative on errors, zero if no connections are present to be accepted, one otherwise.

See also: accept(2).

References ERRNO_TO_PARA_ERROR.

Referenced by accept_sender_client().

◆ create_local_socket()

int create_local_socket ( const char * name )

Create a socket for local communication and listen on it.

Parameters

name	The socket pathname.

This function creates a passive local socket for sequenced, reliable, two-way, connection-based byte streams. The socket file descriptor is set to nonblocking mode and listen(2) is called to prepare the socket for accepting incoming connection requests.

Returns: The file descriptor on success, negative error code on failure.

See also: socket(2),; bind(2),; chmod(2), listen(2), unix(7).

◆ connect_local_socket()

int connect_local_socket ( const char * name )

Prepare, create, and connect to a Unix domain socket for local communication.

Parameters

name	The socket pathname.

This function creates a local socket for sequenced, reliable, two-way, connection-based byte streams.

Returns: The file descriptor of the connected socket on success, negative on errors.

See also: create_local_socket(), unix(7), connect(2).

References ERRNO_TO_PARA_ERROR, and PARA_DEBUG_LOG.

Referenced by send_callback_request().

◆ recv_cred_buffer()

int recv_cred_buffer	(	int	fd,
		char *	buf,
		size_t	size
	)

Receive a buffer and the Unix credentials of the sending process.

Parameters

fd	The file descriptor of the receiving socket.
buf	The buffer to store the received message.
size	The length of buf in bytes.

Returns: Negative on errors, the user id of the sending process on success.

See also: send_cred_buffer and the references given there.

◆ send_cred_buffer()

ssize_t send_cred_buffer	(	int	sock,
		char *	buf
	)

Send a buffer and the credentials of the current process to a socket.

Parameters

sock	The file descriptor of the sending socket.
buf	The zero-terminated buffer to send.

Returns: On success, this call returns the number of bytes sent. On errors, -E_SENDMSG is returned.

See also: recv_cred_buffer, sendmsg(2), socket(7), unix(7).

◆ dccp_available_ccids()

int dccp_available_ccids ( uint8_t ** ccid_array )

Probe the list of DCCP CCIDs configured on this host.

Parameters

ccid_array Pointer to return statically allocated array in.

Returns: Number of elements returned in ccid_array or error.

NB: This feature is only available on Linux > 2.6.30; on older kernels ENOPROTOOPT ("Protocol not available") will be returned.

< Linux socket level.

< List of supported CCIDs.

References DCCP_MAX_HOST_CCIDS, DCCP_SOCKOPT_AVAILABLE_CCIDS, ERRNO_TO_PARA_ERROR, makesock(), PARA_ERROR_LOG, and SOL_DCCP.

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Macros

Functions

Detailed Description

Macro Definition Documentation

◆ SOL_DCCP

◆ MAX_HOSTLEN

◆ BACKLOG

◆ DCCP_MAX_HOST_CCIDS

Function Documentation

◆ flowopt_new()

◆ flowopt_add()

◆ flowopt_cleanup()

◆ parse_cidr()

◆ parse_url()

◆ format_url()

◆ stringify_port()

◆ lookup_address()

◆ makesock()

◆ makesock_addrinfo()

◆ extract_v4_addr()

◆ sockaddr_equal()

◆ para_listen()

◆ para_listen_simple()

◆ remote_name()

◆ generic_max_transport_msg_size()

◆ recv_bin_buffer()

◆ recv_buffer()

◆ para_accept()

◆ create_local_socket()

◆ connect_local_socket()

◆ recv_cred_buffer()

◆ send_cred_buffer()

◆ dccp_available_ccids()