tp4(7) CLIX tp4(7)
NAME
tp4 - ISO/OSI Transport Layer Class 4 Protocol/Internetwork Protocol
STREAMS multiplexer driver
DESCRIPTION
The tp4 driver is a ``cloneable'' (see clone) STREAMS multiplexing driver
that provides the services of the ISO/OSI transport layer class 4 and ISO
Internetwork Protocol (IP).
The tp4 driver communicates using the AT&T Transport Provider Interface
(TPI). Using TPI allows applications to interface with tp4 using the AT&T
Transport Layer Interface (TLI). The driver provides the TLI network
service type T_COTS, a connection-oriented protocol service without
orderly release. The tp4 transport protocols and connectionless network
procotols (clnp) reside within the tp4 multiplexing driver.
The tp4/clnp should be linked above the dlpi STREAMS driver that has been
bound to the Logical Link Class 1 (LLC1) Link Service Access Point (LSAP)
(such as 0xFE) to provide the tp4/clnp/llc1 functionality in accordance
with US GOSIP version 1. The incd daemon performs this binding at boot
time.
The tp4 address is represented in the following structure type:
struct netbuf {
unsigned maxlen;
unsigned len;
char *buf;
};
The maxlen member in the above should be greater or equal to the number of
bytes in buf. The len member should be the number of bytes in buf.
The buf member should point to one of the following transport address
types depending on the TLI call used:
This structure is used in the t_bind() request:
typedef struct {
unsigned len; /* length of address field */
unsigned char addr[32]; /* the address field */
} tsap_selector;
typedef struct {
unsigned len; /* length of address field */
unsigned char addr[20]; /* binary representation of address */
} nsap_address;
This structure is specified in the t_connect() request and returned in the
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t_listen() call:
typedef struct {
tsap_selector tsap; /* Transport SAP ID */
nsap_address nsap; /* Network SAP address */
} tsap_address;
The following functions can be invoked when using the tp4 interface:
The t_open() function creates a logical device for the user to communicate
with the local tp4 entity. The user should specify /dev/tp4 as the device
name when using t_open().
The t_bind() function informs tp4 of the local tsap selector to be
associated with the stream. The t_bind() request contains tsap_selector
in the address specification.
The t_unbind() function disassociates a transport endpoint created by
t_bind().
The t_close() function closes the logical device associated with the tp4
endpoint created by calling t_open().
The t_getinfo() function works as specified in TLI and TPI.
The t_connect() function opens a transport connection with a remote
entity. The t_connect() function contains the tsap_address in the address
specification.
The t_listen() function waits for a connection indication from a remote
tp4 entity. This function returns a tsap_address in the address
specification.
The t_accept() function accepts a connection indication from a remote
entity.
The t_snd() function sends normal or expedited data through an established
tp4 connection.
The t_rcv() function receives normal or expedited data from an established
tp4 connection. If the T_MORE flag is set, the user needs to issue
another t_rcv() function to receive the remainder of a packet.
The t_snddis() function uses the first longword in the udata field of the
t_call() argument to t_snddis() to specify one of the following values as
the disconnect reason:
1 Congestion at tsap.
2 Session entity not attached to tsap.
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128 Normal disconnect initiated by session entity.
133 Protocol error.
The t_rcvdis() function receives an indication that the remote tp4 entity
rejected a proposed connection or simply aborted the connection.
EXAMPLES
1. The following example is an example of a server program:
#include <stdio.h>
#include <tiuser.h>
#include <fcntl.h>
#include <stropts.h>
typedef struct {
unsigned len; /* length of address field */
unsigned char addr[32]; /* the address field */
} tsap_selector;
typedef struct {
unsigned len; /* length of address field */
unsigned char addr[20]; /* binary representation of address */
} nsap_address;
typedef struct {
tsap_selector tsap; /* Transport SAP ID */
nsap_address nsap; /* Network SAP address */
} tsap_address;
#define verbose 1 /* 1 on 0 off */
#define bufsize 1024
#define MAXBUFSZ 4*1024
extern int t_errno;
char data_buf[MAXBUFSZ];
char rdata_buf[MAXBUFSZ];
tsap_address *remaddr;
main()
{
int fd, nbytes, i, flags;
struct t_call *call;
struct t_bind *bind;
tsap_selector *loctsap;
if ((fd = t_open("/dev/tp4", O_RDWR, NULL)) < 0) {
t_error("/dev/tp4 t_open failed");
exit(1);
}
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/* Bind local to TSAP 0009*/
if ((bind = (struct t_bind *) t_alloc(fd, T_BIND, T_ALL)) == NULL) {
t_error("tp4 t_bind failed");
t_close(fd); exit(2);
}
bind->addr.len = sizeof (tsap_selector);
loctsap = (tsap_selector *) bind->addr.buf;
loctsap->len = 2; loctsap->addr[0] = 0x0; loctsap->addr[1] = 0x9;
bind->qlen = 1; /* passive */
if (t_bind(fd, bind, bind) < 0) {
t_error("t_bind failed");
t_close(fd); exit(3);
}
t_free(bind);
/* listen for incomming connection */
if ((call = (struct t_call *)t_alloc(fd, T_CALL, T_ALL)) == NULL) {
t_error("t_alloc of t_call struct failed");
t_close(fd); exit(3);
}
if (verbose) printf("posting a listen\n");
if (t_listen(fd, call) < 0) {
t_error("t_listen failed for listen_fd");
t_close(fd); exit(6);
}
if (verbose) {
remaddr = (tsap_address *)call->addr.buf;
printf("t_listen completed: from_nsap (%d)[%x][%x]... ",
remaddr->nsap.len, remaddr->nsap.addr[0],
remaddr->nsap.addr[1]);
printf("from_tsap (%d)[%x][%x]...\n", remaddr->tsap.len,
remaddr->tsap.addr[0], remaddr->tsap.addr[1]);
}
if (t_accept(fd, fd, call) < 0) {
if (t_errno == TLOOK) {
if (t_close(fd) < 0) {
t_error("t_close failed for listen_fd");
exit(10);
}
}
t_error ("t_accept failed");
exit(7);
}
if (verbose) printf("t_accept success\n");
t_free(call);
for (i = 0; ; i++) {
int total = 0;
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rcv_again:
if ((nbytes = t_rcv(fd, &rdata_buf[total], bufsize-total,
&flags)) < 0) {
printf("loop #%d: ", i);
if (t_errno == TLOOK) {
printf("t_rcv failed, t_look = %d\n", t_look(fd));
t_close(fd); exit(6);
}
t_error("t_rcv failed for fd");
t_close(fd); exit(8);
}
if (strncmp(rdata_buf, "END OF TEST", 11) == 0)
break;
total += nbytes;
if (total != bufsize) {
if (flags & T_MORE) {
if (verbose) printf(".");
goto rcv_again;
}
printf("loop #%d: rcvd %d bytes instead of %d\n",
i, nbytes, bufsize);
continue;
} else if (verbose)
printf("received %d bytes, SUCCESS\n", total);
if ((nbytes = t_snd(fd, rdata_buf, bufsize, 0)) < 0) {
printf("loop #%d: ", i);
t_error("t_snd failed for fd");
t_close(fd); exit(5);
}
if (nbytes != bufsize) {
printf("loop #%d: ", i);
printf("sent %d bytes instead of %d\n");
continue;
}
}
/*
* Send a finish response packet
*/
if ((nbytes = t_snd(fd, "END OF TEST", 11, 0)) != 11) {
printf("Unable to send a fin response\n");
t_error("t_snd failed for fd");
exit(6);
}
for (;;) {
switch(t_look(fd)) {
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case 0: /* No event */
sleep(1);
continue;
case T_DISCONNECT: {
struct t_discon *discon;
discon = (struct t_discon *)
t_alloc(fd, T_DIS, T_ALL);
if (t_rcvdis(fd, discon) < 0) {
t_error("t_rcvdis failed on tp4_fd");
break;
}
printf("Remote disconnect reason %d\n",
discon->reason);
t_free(discon);
t_close(fd); exit(0);
}
default:
printf("unexpected event\n");
}
}
t_close(fd);
}
2. The following is an example of a client program:
#include <stdio.h>
#include <tiuser.h>
#include <fcntl.h>
#include <stropts.h>
typedef struct {
unsigned len; /* length of address field */
unsigned char addr[32]; /* the address field */
} tsap_selector;
typedef struct {
unsigned len; /* length of address field */
unsigned char addr[20]; /* binary representation of address */
} nsap_address;
typedef struct {
tsap_selector tsap; /* Transport SAP ID */
nsap_address nsap; /* Network SAP address */
} tsap_address;
tsap_address remaddr;
#define verbose 1 /* 1 on 0 off */
#define nloop 10
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#define bufsize 1024
#define MAXBUFSZ 4*1024
extern int t_errno;
char data_buf[MAXBUFSZ];
char rdata_buf[MAXBUFSZ];
main()
{
int fd, nbytes, i, j, flags, tbytes, reason;
struct t_call *call;
struct t_bind *bind;
tsap_selector *loctsap;
if ((fd = t_open("/dev/tp4", O_RDWR, NULL)) < 0) {
t_error("/dev/tp4 t_open failed");
exit(1);
}
/* Bind local to TSAP 0008*/
if ((bind = (struct t_bind *) t_alloc(fd, T_BIND, T_ALL)) == NULL) {
t_error("tp4 t_bind failed");
t_close(fd); exit(2);
}
bind->addr.len = sizeof (tsap_selector);
loctsap = (tsap_selector *) bind->addr.buf;
loctsap->len = 2; loctsap->addr[0] = 0x0; loctsap->addr[1] = 0x8;
if (t_bind(fd, bind, bind) < 0) {
t_error("t_bind failed");
t_close(fd); exit(3);
}
t_free(bind);
/* Remote TSAP address */
remaddr.tsap.len = 2;
remaddr.tsap.addr[0] = 0x00; remaddr.tsap.addr[1] = 0x09;
remaddr.nsap.len = 14;
remaddr.nsap.addr[0] = 0x47;
remaddr.nsap.addr[1] = 0x00;
remaddr.nsap.addr[2] = 0x04;
remaddr.nsap.addr[3] = 0x00;
remaddr.nsap.addr[4] = 0x30;
remaddr.nsap.addr[5] = 0x00;
remaddr.nsap.addr[6] = 0x01;
remaddr.nsap.addr[7] = 0x00;
remaddr.nsap.addr[8] = 0x00;
remaddr.nsap.addr[9] = 0x00;
remaddr.nsap.addr[10] = 0x00;
remaddr.nsap.addr[11] = 0x00;
remaddr.nsap.addr[12] = 0x01;
remaddr.nsap.addr[13] = 0x01;
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/* Get a connection established */
if ((call = (struct t_call *)t_alloc(fd, T_CALL, T_ALL)) == NULL) {
t_error("t_alloc of t_call struct failed");
t_close(fd); exit(3);
}
*((tsap_address *)call->addr.buf) = remaddr;
call->addr.len = sizeof (tsap_address);
if (t_connect(fd, call, NULL) < 0) {
if (t_errno == TLOOK) {
printf("t_rcv failed, t_look = %d\n", t_look(fd));
t_close(fd); exit(6);
}
t_error("t_connect failed");
t_close(fd); exit(4);
}
t_free(call);
printf("t_connect success\n");
/* Initialize the data buffer */
for (i = 0; i < bufsize; i++) data_buf[i] = 0xEE;
tbytes = 0;
for (i = 0; i < nloop; i++) {
int total = 0;
if ((nbytes = t_snd(fd, data_buf, bufsize, 0)) < 0) {
printf("loop #%d: ", i);
t_error("t_snd failed for fd");
t_close(fd); exit(5);
}
if (nbytes != bufsize) {
printf("loop #%d: sent %d bytes instead of %d\n",
i, nbytes, bufsize);
continue;
} else {
tbytes += nbytes;
if (verbose)
printf("send %d bytes, SUCCESS\n", nbytes);
}
rcv_again:
if ((nbytes = t_rcv(fd, &rdata_buf[total], bufsize-total,
&flags)) < 0) {
printf("loop #%d: ", i);
if (t_errno == TLOOK) {
printf("t_rcv failed, t_look = %d\n",
t_look(fd));
t_close(fd); exit(6);
}
t_error("t_rcv failed for fd");
t_close(fd); exit(8);
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}
tbytes += nbytes; total += nbytes;
if (total != bufsize) {
if (flags & T_MORE) {
if (verbose) printf(".");
goto rcv_again;
}
printf("loop #%d: rcvd %d bytes instead of %d\n",
i, total, bufsize);
continue;
}
for (j = 0; j < bufsize; j++) {
if ((unsigned char)rdata_buf[j]
!= (unsigned char)0xEE) {
int b;
printf("loop #%d: ", i);
b = (int)rdata_buf[i];
printf("data error at byte #%d (%x)\n", j, b);
goto endloop;
}
}
successloop:
if (verbose)
printf("loop #%d SUCCESS\n", i);
endloop:
}
/* Send a finish packet */
if ((nbytes = t_snd(fd, "END OF TEST", 11, 0)) != 11) {
printf("Unable to send a fin\n");
t_error("t_snd failed for fd");
exit(6);
}
/* Receive fin response packet */
if ((nbytes = t_rcv(fd, rdata_buf, 64, &flags)) < 0) {
if (t_errno == TLOOK) {
printf("failed to rcv a fin response\n", t_look(fd));
t_close(fd); exit(6);
}
t_error("failed to rcv a fin response\n");
t_close(fd); exit(8);
}
if (strncmp(rdata_buf, "END OF TEST", 11) != 0) {
printf("Handshake close failed\n");
exit(10);
}
/* destroy the transport connection */
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if ((call = (struct t_call *)t_alloc(fd, T_CALL, T_ALL)) == NULL) {
t_error("t_alloc of t_call struct failed");
t_close(fd); exit(3);
}
call->udata.len = sizeof (int);
reason = 128; /* NORMAL Disconnect */
call->udata.buf = (char *)&reason;
t_snddis(fd, call);
t_free(call);
sleep(2);
t_close(fd);
}
RELATED INFORMATION
AT&T UNIX System V STREAMS Programmer's Guide, AT&T UNIX System V Network
Programmer's Guide
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