diff options
Diffstat (limited to 'usr.sbin/timed/timed/acksend.c')
| -rw-r--r-- | usr.sbin/timed/timed/acksend.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/usr.sbin/timed/timed/acksend.c b/usr.sbin/timed/timed/acksend.c new file mode 100644 index 0000000..c84f52d --- /dev/null +++ b/usr.sbin/timed/timed/acksend.c @@ -0,0 +1,132 @@ +/*- + * Copyright (c) 1985, 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[] = "@(#)acksend.c 8.1 (Berkeley) 6/6/93"; +#endif /* not lint */ + +#ifdef sgi +#ident "$Revision: 1.6 $" +#endif + +#include "globals.h" + +struct tsp *answer; + +extern u_short sequence; + +void +xmit(type, seq, addr) + int type; + u_int seq; + struct sockaddr_in *addr; +{ + static struct tsp msg; + + msg.tsp_type = type; + msg.tsp_seq = seq; + msg.tsp_vers = TSPVERSION; + (void)strcpy(msg.tsp_name, hostname); + bytenetorder(&msg); + if (sendto(sock, (char *)&msg, sizeof(struct tsp), 0, + (struct sockaddr*)addr, sizeof(struct sockaddr)) < 0) { + trace_sendto_err(addr->sin_addr); + } +} + + +/* + * Acksend implements reliable datagram transmission by using sequence + * numbers and retransmission when necessary. + * If `name' is ANYADDR, this routine implements reliable broadcast. + * + * Because this function calls readmsg(), none of its args may be in + * a message provided by readmsg(). + */ +struct tsp * +acksend(message, addr, name, ack, net, bad) + struct tsp *message; /* this message */ + struct sockaddr_in *addr; /* to here */ + char *name; + int ack; /* look for this ack */ + struct netinfo *net; /* receive from this network */ + int bad; /* 1=losing patience */ +{ + struct timeval twait; + int count; + long msec; + + message->tsp_vers = TSPVERSION; + message->tsp_seq = sequence; + if (trace) { + fprintf(fd, "acksend: to %s: ", + (name == ANYADDR ? "broadcast" : name)); + print(message, addr); + } + bytenetorder(message); + + msec = 200; + count = bad ? 1 : 5; /* 5 packets in 6.4 seconds */ + answer = 0; + do { + if (!answer) { + /* do not go crazy transmitting just because the + * other guy cannot keep our sequence numbers + * straight. + */ + if (sendto(sock, (char *)message, sizeof(struct tsp), + 0, (struct sockaddr*)addr, + sizeof(struct sockaddr)) < 0) { + trace_sendto_err(addr->sin_addr); + break; + } + } + + mstotvround(&twait, msec); + answer = readmsg(ack, name, &twait, net); + if (answer != 0) { + if (answer->tsp_seq != sequence) { + if (trace) + fprintf(fd,"acksend: seq # %u!=%u\n", + answer->tsp_seq, sequence); + continue; + } + break; + } + + msec *= 2; + } while (--count > 0); + sequence++; + + return(answer); +} |
