Unit sdl2_net

Add a socket to a set of sockets to be checked for available data *

Allocate/resize/free a single UDP packet 'size' bytes long. The new packet is returned, or NULL if the function ran out of memory.

Allocate/Free a UDP packet vector (array of packets) of 'howmany' packets, each 'size' bytes long. A pointer to the first packet in the array is returned, or NULL if the function ran out of memory.

Allocate a socket set for use with SDLNet_CheckSockets() This returns a socket set for up to 'maxsockets' sockets, or NULL if the function ran out of memory.

This function checks to see if data is available for reading on the given set of sockets. If 'timeout' is 0, it performs a quick poll, otherwise the function returns when either data is available for reading, or the timeout in milliseconds has elapsed, which ever occurs first. This function returns the number of sockets ready for reading, or -1 if there was an error with the select() system call.

Remove a socket from a set of sockets to be checked for available data *

Free a set of sockets allocated by SDL_NetAllocSocketSet() *

Get the addresses of network interfaces on this system. This returns the number of addresses saved in 'addresses'

Initialize/Cleanup the network API SDL must be initialized before calls to functions in this library, because this library uses utility functions from the SDL library.

This function gets the version of the dynamically linked SDL_net library. it should NOT be used to fill a version structure, instead you should use the SDL_NET_VERSION() macro.

Resolve an ip address to a host name in canonical form. If the ip couldn't be resolved, this function returns NULL, otherwise a pointer to a static buffer containing the hostname is returned. Note that this function is not thread-safe.

After calling SDLNet_CheckSockets(), you can use this function on a socket that was in the socket set, to find out if data is available for reading.

Accept an incoming connection on the given server socket. The newly created socket is returned, or NULL if there was an error.

Close a TCP network socket *

Get the IP address of the remote system associated with the socket. If the socket is a server socket, this function returns NULL.

Open a TCP network socket If ip.host is INADDR_NONE or INADDR_ANY, this creates a local server socket on the given port, otherwise a TCP connection to the remote host and port is attempted. The address passed in should already be swapped to network byte order (addresses returned from SDLNet_ResolveHost() are already in the correct form). The newly created socket is returned, or NULL if there was an error.

Receive up to 'maxlen' bytes of data over the non-server socket 'sock', and store them in the buffer pointed to by 'data'. This function returns the actual amount of data received. If the return value is less than or equal to zero, then either the remote connection was closed, or an unknown socket error occurred.

Send 'len' bytes of 'data' over the non-server socket 'sock' This function returns the actual amount of data sent. If the return value is less than the amount of data sent, then either the remote connection was closed, or an unknown socket error occurred.

Bind the address 'address' to the requested channel on the UDP socket. If the channel is -1, then the first unbound channel that has not yet been bound to the maximum number of addresses will be bound with the given address as it's primary address. If the channel is already bound, this new address will be added to the list of valid source addresses for packets arriving on the channel. If the channel is not already bound, then the address becomes the primary address, to which all outbound packets on the channel are sent. This function returns the channel which was bound, or -1 on error.

Close a UDP network socket *

Get the primary IP address of the remote system associated with the socket and channel. If the channel is -1, then the primary IP port of the UDP socket is returned – this is only meaningful for sockets opened with a specific port. If the channel is not bound and not -1, this function returns NULL.

Open a UDP network socket If 'port' is non-zero, the UDP socket is bound to a local port. The 'port' should be given in native byte order, but is used internally in network (big endian) byte order, in addresses, etc. This allows other systems to send to this socket via a known port.

Receive a single packet from the UDP socket. The returned packet contains the source address and the channel it arrived on. If it did not arrive on a bound channel, the the channel will be set to -1. The channels are checked in highest to lowest order, so if an address is bound to multiple channels, the highest channel with the source address bound will be returned. This function returns the number of packets read from the network, or -1 on error. This function does not block, so can return 0 packets pending.

Receive a vector of pending packets from the UDP socket. The returned packets contain the source address and the channel they arrived on. If they did not arrive on a bound channel, the the channel will be set to -1. The channels are checked in highest to lowest order, so if an address is bound to multiple channels, the highest channel with the source address bound will be returned. This function returns the number of packets read from the network, or -1 on error. This function does not block, so can return 0 packets pending.

Send a single packet to the specified channel. If the channel specified in the packet is -1, the packet will be sent to the address in the 'src' member of the packet. The packet will be updated with the status of the packet after it has been sent. This function returns 1 if the packet was sent, or 0 on error.

NOTE: The maximum size of the packet is limited by the MTU (Maximum Transfer Unit) of the transport medium. It can be as low as 250 bytes for some PPP links, and as high as 1500 bytes for ethernet.

Send a vector of packets to the the channels specified within the packet. If the channel specified in the packet is -1, the packet will be sent to the address in the 'src' member of the packet. Each packet will be updated with the status of the packet after it has been sent, -1 if the packet send failed. This function returns the number of packets sent.

Set the percentage of simulated packet loss for packets sent on the socket. *

Unbind all addresses from the given channel *

This macro can be used to fill a version structure with the compile-time version of the SDL_net library.

"The following type designates an unsigned integer type [or signed respectivly] with the property that any valid pointer to void can be converted to this type, then converted back to a pointer to void, and the result will compare equal to the original pointer: uintptr_t" Source: https://pubs.opengroup.org/onlinepubs/000095399/basedefs/stdint.h.html

Any network socket can be safely cast to this socket type *

Data types for all compilers

Resolve a host name and port to an IP address in network form. If the function succeeds, it will return 0. If the host couldn't be resolved, the host portion of the returned address will be INADDR_NONE, and the function will return -1. If 'host' is NULL, the resolved host will be set to INADDR_ANY.

The maximum addresses bound to a single UDP socket channel *

The maximum channels on a a UDP socket *

Printable format: "%d.%d.%d", MAJOR, MINOR, PATCHLEVEL *