1/* $NetBSD: net.c,v 1.36 2019/03/31 20:08:45 christos 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#endif 68 69#include "net.h" 70 71/* 72 * Send a packet and wait for a reply, with exponential backoff. 73 * 74 * The send routine must return the actual number of bytes written, 75 * or -1 on error. 76 * 77 * The receive routine can indicate success by returning the number of 78 * bytes read; it can return 0 to indicate EOF; it can return -1 with a 79 * non-zero errno to indicate failure; finally, it can return -1 with a 80 * zero errno to indicate it isn't done yet. 81 */ 82ssize_t 83sendrecv(struct iodesc *d, 84 ssize_t (*sproc)(struct iodesc *, void *, size_t), 85 void *sbuf, size_t ssize, 86 ssize_t (*rproc)(struct iodesc *, void *, size_t, saseconds_t), 87 void *rbuf, size_t rsize) 88{ 89 ssize_t cc; 90 satime_t t, tlast; 91 saseconds_t tmo, tleft; 92 93#ifdef NET_DEBUG 94 if (debug) 95 printf("%s: called\n", __func__); 96#endif 97 98 tmo = MINTMO; 99 tlast = 0; 100 tleft = 0; 101 t = getsecs(); 102 for (;;) { 103 if (tleft <= 0) { 104 if (tmo >= MAXTMO) { 105 errno = ETIMEDOUT; 106 return -1; 107 } 108 cc = (*sproc)(d, sbuf, ssize); 109 110 tleft = tmo; 111 tmo <<= 1; 112 if (tmo > MAXTMO) 113 tmo = MAXTMO; 114 115 if (cc == -1) { 116 /* Error on transmit; wait before retrying */ 117 while ((getsecs() - t) < tmo) 118 delay(); 119 tleft = 0; 120 continue; 121 } 122 if ((size_t)cc < ssize) 123 panic("%s: short write! (%zd < %zu)", __func__, 124 cc, ssize); 125 126 tlast = t; 127 } 128 129 /* Try to get a packet and process it. */ 130 cc = (*rproc)(d, rbuf, rsize, tleft); 131 /* Return on data, EOF or real error. */ 132 if (cc != -1 || errno != 0) 133 return cc; 134 135 /* Timed out or didn't get the packet we're waiting for */ 136 t = getsecs(); 137 tleft -= t - tlast; 138 tlast = t; 139 } 140} 141