General updates of socket APIs

Table 1 lists the general updates made to the IP socket APIs.

Table 1. Summary of new and changed Communications Server socket APIs
Socket API	Function call/Parameter	Rel.	Description	Reason for change
Call instruction CICS C socket calls CICS call instruction IMS call instruction Language Environment C/C++ socket Macro REXX socket UNIX System Services Assembler Callable Service	New SIOCGPARTNERINF O ioctl	V1R12	Provides an interface for an application to retrieve security information about its partner.	Trusted TCP connections
	New SIOCSPARTNERINFO ioctl	V1R12	Enables an application to avoid suspending while retrieving the partner security credentials with the SIOCGPARTNERINFO ioctl.	Trusted TCP connections
Call instruction CICS® C CICS sockets extended MACRO REXX socket UNIX assembler callable services XL C/C++	bind2addrsel()	V1R12	These APIs support the bind2addrsel() call defined in RFC 5014. This function is only supported for AF_INET6 sockets. The bind2addrsel() call binds the input socket to the source IP address TCP/IP would select for the input destination IPv6 address. The bind2addrsel function is supported in USS Assembler Callable Services with the new BPX1BAS and BPX4BAS entry points.	Configurable default address selection policy table
	getsockopt, setsockopt	V1R12	These APIs support a new socket option at the IPPROTO_IPV6 level: IPV6_ADDR_PREFERENCES as defined in RFC 5014. This socket option is only available for AF_INET6 sockets. Use this option to set and get the source IP address selection preferences affecting all packets sent by a given socket.	Configurable default address selection policy table
	inet6_is_srcaddr()	V1R12	These APIs support the inet6_is_srcaddr() call defined in RFC 5014. The inet6_is_srcaddr() API call tests whether the input IPv6 address conforms to the input address selection preference flags. The inet6_is_srcaddr function is supported in USS Assembler Callable Services as a PFS control function, BPX1PCT (PC#IsSrcAddr) or BPX4PCT (PC#IsSrcAddr).	Configurable default address selection policy table
	SIOCTTLSCTL ioctl - TTLS_STOP_CONNECTION request	V2R1	The TTLS_STOP_CONNECTION request returns errno Eproto in these conditions: If the application has not read all the data received on the secure connection, the request fails with return code of -1, errno of Eproto , and errno junior of JrTTLSStopReadDataPending. If the application has outstanding write requests on the connection, the request fails with return code of -1, errno of Eproto, and errno junior of JrTTLSStopWriteDataPending.	Data security issue with AT-TLS stopped connection
Call instruction CICS C CICS sockets extended MACRO REXX socket XL C/C++	getaddrinfo()	V1R12	The addrinfo structure is enhanced to comply with RFC 5014. You can use the enhanced structure to pass source IP source address preference flags in the hints parameter of getaddrinfo().	Configurable default address selection policy table
Call instruction CICS C socket calls CICS call instruction Language Environment C/C++ socket Macro UNIX System Services Assembler Callable Service	SIOCTTLSCTL ioctl	V2R1	TTLSi_SSL_Prot New value TTLS_PROT_TLSV1_2 (X'0303') TTLSi_Neg_Cipher New value TTLS_4CHAR_CIPHER (X'4X') TTLSi_Neg_Cipher4 New field containing four character negotiated cipher	AT-TLS support for TLS v1.2 and related features
REXX Socket	SIOCTTLSCTL	V2R1	A new four byte cipher field is returned. The existing two character cipher contains "4X" if the cipher cannot be represented with two bytes. A new value of X'0303' can be returned to identify the SSL protocol that is in use as TLS v1.2.	AT-TLS support for TLS v1.2 and related features
LE C/C++	Recv(), recvfrom(), recvmsg()	V2R1	Add new MSG_CONNTERM value in msg_flags of sys/socket.h to indicate the receive request completes only when a TCP connection is terminated.	Enhanced Fast Path socket support
TCP/IP C UNIX assembler callable services	getsockopt()	V1R12	When invoked with the SO_CLUSTERCONNTYPE option, this socket API returns an internal indicator for OSA-Express QDIO interfaces with CHPID type OSX or OSM.	z/OS Communications Server in an ensemble
UNIX assembler callable services	recv (BPX1RCV, BPX4RCV), recvfrom (BPX1RFM, BPX4RFM), recvmsg (BPX2RMS, BPX4RMS) Asyncio(BPX1AIO or BPX4AIO): AioCmd=Aio#Recv, AioCmd=Aio#RecvFrom, AioCmd=Aio#RecvMsg)	V2R1	Add new MSG_CONNTERM value in msg_flags of BPXYMSGF.macro to indicate the receive request completes only when a TCP connection is terminated.	Enhanced Fast Path socket support
XL C/C++ UNIX assembler callable services	SIOCSVIPA, SIOCSVIPA6	V2R1	New option: DVR_DEFINE_AFFINITY - Create DVIPA with affinity	Affinity for application-instance DIVPAs