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 */
82 ssize_t
sendrecv(struct iodesc * d,ssize_t (* sproc)(struct iodesc *,void *,size_t),void * sbuf,size_t ssize,ssize_t (* rproc)(struct iodesc *,void *,size_t,saseconds_t),void * rbuf,size_t rsize)83 sendrecv(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