FreeBSD/Linux Kernel Cross Reference
sys/lib/libsa/net.c
1 /* $NetBSD: net.c,v 1.28 2003/08/31 22:40:48 fvdl 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 && (size_t)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 }
Cache object: f76e18208a1e4bbdcb2448c5b5fd50f5
|