1/* $NetBSD: net.c,v 1.34 2009/01/31 06:22:46 isaki 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#ifdef _STANDALONE 59#include "stand.h" 60#define delay() 61#else 62#include <errno.h> 63#include <stdio.h> 64#include <unistd.h> 65#define panic printf 66#define delay() usleep(100000) 67#define getsecs() time(NULL) 68#endif 69 70#include "net.h" 71 72/* 73 * Send a packet and wait for a reply, with exponential backoff. 74 * 75 * The send routine must return the actual number of bytes written, 76 * or -1 on error. 77 * 78 * The receive routine can indicate success by returning the number of 79 * bytes read; it can return 0 to indicate EOF; it can return -1 with a 80 * non-zero errno to indicate failure; finally, it can return -1 with a 81 * zero errno to indicate it isn't done yet. 82 */ 83ssize_t 84sendrecv(struct iodesc *d, 85 ssize_t (*sproc)(struct iodesc *, void *, size_t), 86 void *sbuf, size_t ssize, 87 ssize_t (*rproc)(struct iodesc *, void *, size_t, saseconds_t), 88 void *rbuf, size_t rsize) 89{ 90 ssize_t cc; 91 satime_t t, tlast; 92 saseconds_t tmo, tleft; 93 94#ifdef NET_DEBUG 95 if (debug) 96 printf("sendrecv: called\n"); 97#endif 98 99 tmo = MINTMO; 100 tlast = 0; 101 tleft = 0; 102 t = getsecs(); 103 for (;;) { 104 if (tleft <= 0) { 105 if (tmo >= MAXTMO) { 106 errno = ETIMEDOUT; 107 return -1; 108 } 109 cc = (*sproc)(d, sbuf, ssize); 110 111 tleft = tmo; 112 tmo <<= 1; 113 if (tmo > MAXTMO) 114 tmo = MAXTMO; 115 116 if (cc == -1) { 117 /* Error on transmit; wait before retrying */ 118 while ((getsecs() - t) < tmo) 119 delay(); 120 tleft = 0; 121 continue; 122 } 123 if ((size_t)cc < ssize) 124 panic("sendrecv: short write! (%zd < %zu)", 125 cc, ssize); 126 127 tlast = t; 128 } 129 130 /* Try to get a packet and process it. */ 131 cc = (*rproc)(d, rbuf, rsize, tleft); 132 /* Return on data, EOF or real error. */ 133 if (cc != -1 || errno != 0) 134 return cc; 135 136 /* Timed out or didn't get the packet we're waiting for */ 137 t = getsecs(); 138 tleft -= t - tlast; 139 tlast = t; 140 } 141} 142