1 /* $NetBSD: net.c,v 1.27 2000/10/25 01:49:55 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1992 Regents of the University of California. 5 * All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Lawrence Berkeley Laboratory and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp (LBL) 40 */ 41 42 #include <sys/param.h> 43 #include <sys/socket.h> 44 45 #ifdef _STANDALONE 46 #include <lib/libkern/libkern.h> 47 #else 48 #include <string.h> 49 #endif 50 51 #include <net/if.h> 52 #include <net/if_ether.h> 53 54 #include <netinet/in.h> 55 #include <netinet/in_systm.h> 56 #include <netinet/ip.h> 57 58 #include "stand.h" 59 #include "net.h" 60 61 /* 62 * Send a packet and wait for a reply, with exponential backoff. 63 * 64 * The send routine must return the actual number of bytes written, 65 * or -1 on error. 66 * 67 * The receive routine can indicate success by returning the number of 68 * bytes read; it can return 0 to indicate EOF; it can return -1 with a 69 * non-zero errno to indicate failure; finally, it can return -1 with a 70 * zero errno to indicate it isn't done yet. 71 */ 72 ssize_t 73 sendrecv(d, sproc, sbuf, ssize, rproc, rbuf, rsize) 74 struct iodesc *d; 75 ssize_t (*sproc)(struct iodesc *, void *, size_t); 76 void *sbuf; 77 size_t ssize; 78 ssize_t (*rproc)(struct iodesc *, void *, size_t, time_t); 79 void *rbuf; 80 size_t rsize; 81 { 82 ssize_t cc; 83 time_t t, tmo, tlast; 84 long tleft; 85 86 #ifdef NET_DEBUG 87 if (debug) 88 printf("sendrecv: called\n"); 89 #endif 90 91 tmo = MINTMO; 92 tlast = tleft = 0; 93 t = getsecs(); 94 for (;;) { 95 if (tleft <= 0) { 96 if (tmo >= MAXTMO) { 97 errno = ETIMEDOUT; 98 return -1; 99 } 100 cc = (*sproc)(d, sbuf, ssize); 101 if (cc != -1 && cc < ssize) 102 panic("sendrecv: short write! (%d < %d)", 103 cc, ssize); 104 105 tleft = tmo; 106 tmo <<= 1; 107 if (tmo > MAXTMO) 108 tmo = MAXTMO; 109 110 if (cc == -1) { 111 /* Error on transmit; wait before retrying */ 112 while ((getsecs() - t) < tmo); 113 tleft = 0; 114 continue; 115 } 116 117 tlast = t; 118 } 119 120 /* Try to get a packet and process it. */ 121 cc = (*rproc)(d, rbuf, rsize, tleft); 122 /* Return on data, EOF or real error. */ 123 if (cc != -1 || errno != 0) 124 return (cc); 125 126 /* Timed out or didn't get the packet we're waiting for */ 127 t = getsecs(); 128 tleft -= t - tlast; 129 tlast = t; 130 } 131 } 132