libsocket

#Overview

libsocket is meant to work exactly the same as the regular socket APIs when using it under IPv4 and UDP. However, under the hood, it uses UNIX sockets to communicate. As such, the only supported address is 127.0.0.1 (or localhost). Placing any other address in s_sendto does nothing. s_recvfrom will always return an address from 127.0.0.1.

If you follow the Socket Programming Tips for UDP, the only change you’ll need to make is to replace the socket, bind, recvfrom, sendto calls with ones prepended with s_.

#s_socket

int s_socket(int domain, int type, int protocol);

#Parameters

• int domain: Only supports AF_INET (IPv4).
• int type: Only supports SOCK_DGRAM (connectionless datagrams).

#Returns

int: Returns the file descriptor of the created socket or -1 if an error occured. Check errno for the specific error.

#s_bind

int s_bind(int sock, const struct sockaddr* addr, socklen_t len);

#Parameters

• int sock: Socket to bind address to
• const struct sockaddr* addr: Only supports addresses of type sockaddr_in.
• socklen_t len: Unused; here for compatibility with the standard socket API.

#Returns

int: Returns 0 on success or -1 if an error occured. Check errno for the specific error.

#s_recvfrom

ssize_t s_recvfrom(int sock, void* buf, size_t len, int flags, struct sockaddr* addr, socklen_t* addrlen);

#Parameters

• int sock: Socket to bind address to
• void* buf: Buffer to write data to
• size_t len: Max size of buffer in bytes
• int flags: See the man page for recvfrom
• struct sockaddr* addr: Will write out the address the data was received from (always 127.0.0.1 + port).
• socklen_t addrlen: Unused; here for compatibility with the standard socket API.

#Returns

ssize_t: Returns the number of bytes received or -1 if an error occured. Check errno for the specific error.

#s_sendto

ssize_t s_sendto(int sock, const void* buf, size_t len, int flags, const struct sockaddr* addr, socklen_t addrlen);

#Parameters

• int sock: Socket to bind address to
• void* buf: Buffer to read data from
• size_t len: Size of data to read in bytes
• int flags: See the man page for recvfrom
• struct sockaddr* addr: Only supports sockaddr_in addresses. The in_addr field is ignored.
• socklen_t addrlen: Unused; here for compatibility with the standard socket API.

#Returns

ssize_t: Returns the number of bytes sent or -1 if an error occured. Check errno for the specific error.