|
|
HP-UX Reference > Tt_open(3)HP-UX 11i Version 2: December 2007 Update |
|
NAMEt_open() — establish a transport endpoint SYNOPSIS#include <fcntl.h> #include <xti.h> /* for X/OPEN Transport Interface - XTI */ /* or */ #include <tiuser.h> /* for Transport Layer Interface - TLI */ int t_open (name, oflag, info); char *name; int oflag; struct t_info *info; DESCRIPTIONThe t_open() function must be called as the first step in the initialization of a transport endpoint. This function establishes a transport endpoint by opening a file that identifies a particular transport provider and returning a file descriptor that identifies that endpoint. The argument name points to a file name that identifies a transport provider. When using HP XTI to connect to the OSI protocol stack, name must be /dev/ositpi for the connection-mode service, or /dev/osicltpi for the connectionless service. When using HP XTI to connect to the TCP protocol stack, name should be /dev/tcp. For UDP, name should be /dev/udp. (See also the OBSOLESCENT INTERFACES section.) For TLI, use the device file name of the transport provider desired. Note that HP TCP/UDP/IP and HP OSI COTS and CLTS only support XTI. oflag identifies any open flags (as in open()) and is constructed from O_RDWR optionally or-ed with O_NONBLOCK. These flags are defined by the header file <fcntl.h>. t_open() returns a file descriptor that will be used by all subsequent functions to identify the particular local transport endpoint. This function also returns various default characteristics of the underlying transport protocol by setting fields in the t_info structure. This argument points to a t_info which contains the following members: t_scalar_t addr; /* max size of the transport protocol */ /* address */ t_scalar_t options; /* max number of bytes of */ /* protocol-specific options */ t_scalar_t tsdu; /* max size of a transport service data */ /* unit (TSDU) */ t_scalar_t etsdu; /* max size of an expedited transport */ /* service data unit (ETSDU) */ t_scalar_t connect; /* max amount of data allowed on */ /* connection establishment functions */ t_scalar_t discon; /* max amount of data allowed on */ /* t_snddis and t_rcvdis functions */ t_scalar_t servtype; /* service type supported by the */ /* transport provider */ t_scalar_t flags; /* other info about the transport provider */ The values of the fields have the following meanings:
If a transport user is concerned with protocol independence, the above sizes may be accessed to determine how large the buffer must be to hold each piece of information. Alternatively, the t_alloc() function may be used to allocate these buffers. An error will result if a transport user exceeds the allowed data size on any function. The servtype field of info specifies one of the following values on return:
If info is set to a null pointer by the transport user, no protocol information is returned by t_open(). Thread-SafenessThe t_open() function is safe to be called by multithreaded applications, and it is thread-safe for both POSIX Threads and DCE User Threads. It has a cancellation point. It is neither async-cancel safe nor async-signal safe. Finally, it is not fork-safe. Obsolescent InterfacesWhen using TCP and UDP through HP XTI, name can be /dev/inet_cots and /dev/inet_clts, respectively. These names are supported for backward-compatibility purposes. They might not be supported in future releases, and they should be replaced with /dev/tcp and /dev/udp, respectively. RETURN VALUEA valid endpoint identifier is returned upon successful completion. Otherwise, a value of -1 is returned and t_errno is set to indicate an error. HP OSI does not support the T_COTS_ORD servtype. ERRORSOn error, t_errno is set to one of the following:
|
|