1 /* $NetBSD: net.c,v 1.30 2006/01/21 10:06:06 dsl 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 */ 83 ssize_t 84 sendrecv(d, sproc, sbuf, ssize, rproc, rbuf, rsize) 85 struct iodesc *d; 86 ssize_t (*sproc)(struct iodesc *, void *, size_t); 87 void *sbuf; 88 size_t ssize; 89 ssize_t (*rproc)(struct iodesc *, void *, size_t, time_t); 90 void *rbuf; 91 size_t rsize; 92 { 93 ssize_t cc; 94 time_t t, tmo, tlast; 95 long tleft; 96 97 #ifdef NET_DEBUG 98 if (debug) 99 printf("sendrecv: called\n"); 100 #endif 101 102 tmo = MINTMO; 103 tlast = tleft = 0; 104 t = getsecs(); 105 for (;;) { 106 if (tleft <= 0) { 107 if (tmo >= MAXTMO) { 108 errno = ETIMEDOUT; 109 return -1; 110 } 111 cc = (*sproc)(d, sbuf, ssize); 112 113 tleft = tmo; 114 tmo <<= 1; 115 if (tmo > MAXTMO) 116 tmo = MAXTMO; 117 118 if (cc == -1) { 119 /* Error on transmit; wait before retrying */ 120 while ((getsecs() - t) < tmo) 121 delay(); 122 tleft = 0; 123 continue; 124 } 125 if (cc < ssize) 126 panic("sendrecv: short write! (%zd < %zd)", 127 cc, ssize); 128 129 tlast = t; 130 } 131 132 /* Try to get a packet and process it. */ 133 cc = (*rproc)(d, rbuf, rsize, tleft); 134 /* Return on data, EOF or real error. */ 135 if (cc != -1 || errno != 0) 136 return (cc); 137 138 /* Timed out or didn't get the packet we're waiting for */ 139 t = getsecs(); 140 tleft -= t - tlast; 141 tlast = t; 142 } 143 } 144