diff options
Diffstat (limited to 'usr.bin/tn3270/api/api_exch.c')
| -rw-r--r-- | usr.bin/tn3270/api/api_exch.c | 429 |
1 files changed, 429 insertions, 0 deletions
diff --git a/usr.bin/tn3270/api/api_exch.c b/usr.bin/tn3270/api/api_exch.c new file mode 100644 index 0000000..a4626b9 --- /dev/null +++ b/usr.bin/tn3270/api/api_exch.c @@ -0,0 +1,429 @@ +/*- + * Copyright (c) 1988, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef lint +static char sccsid[] = "@(#)api_exch.c 8.1 (Berkeley) 6/6/93"; +#endif /* not lint */ + +#include <stdio.h> + +#include "../general/general.h" + +#include "api_exch.h" + +static int sock; /* Socket number */ + +static char whoarewe[40] = ""; +#define WHO_ARE_WE() fprintf(stderr, "(API %s) ", whoarewe); + +static enum {CONTENTION, SEND, RECEIVE } conversation; + +static struct exch_exch exch_state; + +static unsigned int + my_sequence, + your_sequence; + +static char ibuffer[4000], *ibuf_next, *ibuf_last; +#define IBUFADDED(i) ibuf_last += (i) +#define IBUFAVAILABLE() (ibuf_last-ibuf_next) +#define IBUFFER() ibuffer +#define IBUFFREE() (ibuffer+sizeof ibuffer-ibuf_last-1) +#define IBUFGETBYTES(w,l) { memcpy(w, ibuf_next, l); ibuf_next += l; } +#define IBUFRESET() (ibuf_next = ibuf_last = ibuffer) + +char obuffer[4000], *obuf_next; +#define OBUFADDBYTES(w,l) { memcpy(obuf_next, w, l); obuf_next += l; } +#define OBUFAVAILABLE() (obuf_next - obuffer) +#define OBUFFER() obuffer +#define OBUFRESET() obuf_next = obuffer +#define OBUFROOM() (obuffer+sizeof obuffer-obuf_next) + + +static int +outflush() +{ + int length = OBUFAVAILABLE(); + + if (length != 0) { + if (write(sock, OBUFFER(), length) != length) { + WHO_ARE_WE(); + perror("write"); + return -1; + } + OBUFRESET(); + } + return 0; /* All OK */ +} + + +static int +iget(location, length) +char *location; +int length; +{ + int count; + + if (OBUFAVAILABLE()) { + if (outflush() == -1) { + return -1; + } + } + if ((count = IBUFAVAILABLE()) != 0) { + if (count > length) { + count = length; + } + IBUFGETBYTES(location, count); + length -= count; + location += count; + } + while (length) { + if (ibuf_next == ibuf_last) { + IBUFRESET(); + } + if ((count = read(sock, IBUFFER(), IBUFFREE())) < 0) { + WHO_ARE_WE(); + perror("read"); + return -1; + } + if (count == 0) { + /* Reading past end-of-file */ + WHO_ARE_WE(); + fprintf(stderr, "End of file read\r\n"); + return -1; + } + IBUFADDED(count); + if (count > length) { + count = length; + } + IBUFGETBYTES(location, count); + length -= count; + location += count; + } + return 0; +} + +static char * +exch_to_ascii(exch) +int exch; /* opcode to decode */ +{ + switch (exch) { + case EXCH_EXCH_COMMAND: + return "Command"; + case EXCH_EXCH_TYPE: + return "Type"; + case EXCH_EXCH_TURNAROUND: + return "Turnaround"; + case EXCH_EXCH_RTS: + return "Request to Send"; + default: + { + static char unknown[40]; + + sprintf(unknown, "(Unknown exchange 0x%02x)", exch&0xff); + return unknown; + } + } +} + +/* + * Send the exch structure, updating the sequnce number field. + */ + +static int +send_state() +{ + if (OBUFROOM() < sizeof exch_state) { + if (outflush() == -1) { + return -1; + } + } + my_sequence = (my_sequence+1)&0xff; + exch_state.my_sequence = my_sequence; + exch_state.your_sequence = your_sequence; + OBUFADDBYTES((char *)&exch_state, sizeof exch_state); + return 0; +} + +/* + * Receive the exch structure from the other side, checking + * sequence numbering. + */ + +static int +receive_state() +{ + if (iget((char *)&exch_state, sizeof exch_state) == -1) { + return -1; + } + if (conversation != CONTENTION) { + if (exch_state.your_sequence != my_sequence) { + WHO_ARE_WE(); + fprintf(stderr, "Send sequence number mismatch.\n"); + return -1; + } + if (exch_state.my_sequence != ((++your_sequence)&0xff)) { + WHO_ARE_WE(); + fprintf(stderr, "Receive sequence number mismatch.\n"); + return -1; + } + } + your_sequence = exch_state.my_sequence; + return 0; +} + +static int +enter_receive() +{ + switch (conversation) { + case CONTENTION: + exch_state.opcode = EXCH_EXCH_TURNAROUND; + if (send_state() == -1) { + return -1; + } + if (receive_state() == -1) { + return -1; + } + if (exch_state.opcode != EXCH_EXCH_RTS) { + WHO_ARE_WE(); + fprintf(stderr, "In CONTENTION state: "); + if (exch_state.opcode == EXCH_EXCH_TURNAROUND) { + fprintf(stderr, + "Both sides tried to enter RECEIVE state.\n"); + } else { + fprintf(stderr, + "Protocol error trying to enter RECEIVE state.\n"); + } + return -1; + } + break; + case SEND: + exch_state.opcode = EXCH_EXCH_TURNAROUND; + if (send_state() == -1) { + return -1; + } + break; + } + conversation = RECEIVE; + return 0; +} + +static int +enter_send() +{ + switch (conversation) { + case CONTENTION: + exch_state.opcode = EXCH_EXCH_RTS; + if (send_state() == -1) { + return -1; + } + /* fall through */ + case RECEIVE: + if (receive_state() == -1) { + return -1; + } + if (exch_state.opcode != EXCH_EXCH_TURNAROUND) { + WHO_ARE_WE(); + fprintf(stderr, "Conversation error - both sides in SEND state.\n"); + return -1; + } + } + conversation = SEND; + return 0; +} + +int +api_exch_nextcommand() +{ + if (conversation != RECEIVE) { + if (enter_receive() == -1) { + return -1; + } + } + if (receive_state() == -1) { + return -1; + } + if (exch_state.opcode != EXCH_EXCH_COMMAND) { + WHO_ARE_WE(); + fprintf(stderr, "Expected a %s exchange, received a %s exchange.\n", + exch_to_ascii(EXCH_EXCH_COMMAND), exch_to_ascii(exch_state.opcode)); + return -1; + } + return exch_state.command_or_type; +} + + +int +api_exch_incommand(command) +int command; +{ + int i; + + if ((i = api_exch_nextcommand()) == -1) { + return -1; + } + if (i != command) { + WHO_ARE_WE(); + fprintf(stderr, "Expected API command 0x%x, got API command 0x%x.\n", + command, i); + return -1; + } + return 0; +} + + +int +api_exch_outcommand(command) +int command; +{ + if (conversation != SEND) { + if (enter_send() == -1) { + return -1; + } + } + exch_state.command_or_type = command; + exch_state.opcode = EXCH_EXCH_COMMAND; + if (send_state() == -1) { + return -1; + } else { + return 0; + } +} + + +int +api_exch_outtype(type, length, location) +int + type, + length; +char + *location; +{ + int netleng = length; + + if (conversation != SEND) { + if (enter_send() == -1) { + return -1; + } + } + exch_state.opcode = EXCH_EXCH_TYPE; + exch_state.command_or_type = type; + exch_state.length = netleng; + if (send_state() == -1) { + return -1; + } + if (length) { + if (OBUFROOM() > length) { + OBUFADDBYTES(location, length); + } else { + if (outflush() == -1) { + return -1; + } + if (write(sock, location, length) != length) { + WHO_ARE_WE(); + perror("write"); + return -1; + } + } + } + return 0; +} + + +int +api_exch_intype(type, length, location) +int + type, + length; +char + *location; +{ + int netleng = length; + + if (conversation != RECEIVE) { + if (enter_receive() == -1) { + return -1; + } + } + if (receive_state() == -1) { + return -1; + } + if (exch_state.opcode != EXCH_EXCH_TYPE) { + WHO_ARE_WE(); + fprintf(stderr, + "Expected to receive a %s exchange, received a %s exchange.\n", + exch_to_ascii(EXCH_EXCH_TYPE), exch_to_ascii(exch_state.opcode)); + return -1; + } + if (exch_state.command_or_type != type) { + WHO_ARE_WE(); + fprintf(stderr, "Expected type 0x%x, got type 0x%x.\n", + type, exch_state.command_or_type); + return -1; + } + if (exch_state.length != netleng) { + fprintf(stderr, "Type 0x%x - expected length %d, received length %u.\n", + type, length, exch_state.length); + return -1; + } + if (iget(location, length) == -1) { + return -1; + } + return 0; +} + +int +api_exch_flush() +{ + return outflush(); +} + +int +api_exch_init(sock_number, ourname) +int sock_number; +char *ourname; +{ + extern char *strcpy(); + + sock = sock_number; + (void) strcpy(whoarewe, ourname); /* For error messages */ + + my_sequence = your_sequence = 0; + + conversation = CONTENTION; /* We don't know which direction */ + + IBUFRESET(); + OBUFRESET(); + + return 0; +} |
