1 /* $NetBSD: net.c,v 1.20 1997/12/26 22:41:30 scottr 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. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp (LBL)
36 */
37
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD: stable/12/stand/libsa/net.c 370814 2021-10-17 18:45:28Z kevans $");
40
41 #include <sys/param.h>
42 #include <sys/socket.h>
43
44 #include <string.h>
45
46 #include <net/if.h>
47 #include <netinet/in.h>
48 #include <netinet/if_ether.h>
49 #include <netinet/in_systm.h>
50
51 #include <netinet/ip.h>
52 #include <netinet/ip_var.h>
53 #include <netinet/udp.h>
54 #include <netinet/udp_var.h>
55
56 #include "stand.h"
57 #include "net.h"
58
59 /*
60 * Maximum wait time for sending and receiving before we give up and timeout.
61 * If set to 0, operations will eventually timeout completely, but send/recv
62 * timeouts must progress exponentially from MINTMO to MAXTMO before final
63 * timeout is hit.
64 */
65 #ifndef MAXWAIT
66 #define MAXWAIT 300 /* seconds */
67 #endif
68
69 #if MAXWAIT < 0
70 #error MAXWAIT must not be a negative number
71 #endif
72
73 /*
74 * Send a packet and wait for a reply, with exponential backoff.
75 *
76 * The send routine must return the actual number of bytes written,
77 * or -1 on error.
78 *
79 * The receive routine can indicate success by returning the number of
80 * bytes read; it can return 0 to indicate EOF; it can return -1 with a
81 * non-zero errno to indicate failure; finally, it can return -1 with a
82 * zero errno to indicate it isn't done yet.
83 */
84 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 **,void **,time_t,void *),void ** pkt,void ** payload,void * recv_extra)85 sendrecv(struct iodesc *d,
86 ssize_t (*sproc)(struct iodesc *, void *, size_t),
87 void *sbuf, size_t ssize,
88 ssize_t (*rproc)(struct iodesc *, void **, void **, time_t, void *),
89 void **pkt, void **payload, void *recv_extra)
90 {
91 ssize_t cc;
92 time_t t, tmo, tlast;
93 time_t tref;
94 long tleft;
95
96 #ifdef NET_DEBUG
97 if (debug)
98 printf("sendrecv: called\n");
99 #endif
100
101 tmo = MINTMO;
102 tlast = 0;
103 tleft = 0;
104 tref = getsecs();
105 t = getsecs();
106 for (;;) {
107 if (MAXWAIT > 0 && (getsecs() - tref) >= MAXWAIT) {
108 errno = ETIMEDOUT;
109 return -1;
110 }
111 if (tleft <= 0) {
112 if (tmo >= MAXTMO) {
113 errno = ETIMEDOUT;
114 return -1;
115 }
116 cc = (*sproc)(d, sbuf, ssize);
117 if (cc != -1 && cc < ssize)
118 panic("sendrecv: short write! (%zd < %zd)",
119 cc, ssize);
120
121 tleft = tmo;
122 tmo += MINTMO;
123 if (tmo > MAXTMO)
124 tmo = MAXTMO;
125
126 if (cc == -1) {
127 /* Error on transmit; wait before retrying */
128 while ((getsecs() - t) < tmo)
129 ;
130 tleft = 0;
131 continue;
132 }
133
134 tlast = t;
135 }
136
137 /* Try to get a packet and process it. */
138 cc = (*rproc)(d, pkt, payload, tleft, recv_extra);
139 /* Return on data, EOF or real error. */
140 if (cc != -1 || (errno != 0 && errno != ETIMEDOUT))
141 return (cc);
142
143 /* Timed out or didn't get the packet we're waiting for */
144 t = getsecs();
145 tleft -= t - tlast;
146 tlast = t;
147 }
148 }
149
150 /*
151 * Like inet_addr() in the C library, but we only accept base-10.
152 * Return values are in network order.
153 */
154 n_long
inet_addr(char * cp)155 inet_addr(char *cp)
156 {
157 u_long val;
158 int n;
159 char c;
160 u_int parts[4];
161 u_int *pp = parts;
162
163 for (;;) {
164 /*
165 * Collect number up to ``.''.
166 * Values are specified as for C:
167 * 0x=hex, 0=octal, other=decimal.
168 */
169 val = 0;
170 while ((c = *cp) != '\0') {
171 if (c >= '0' && c <= '9') {
172 val = (val * 10) + (c - '0');
173 cp++;
174 continue;
175 }
176 break;
177 }
178 if (*cp == '.') {
179 /*
180 * Internet format:
181 * a.b.c.d
182 * a.b.c (with c treated as 16-bits)
183 * a.b (with b treated as 24 bits)
184 */
185 if (pp >= parts + 3 || val > 0xff)
186 goto bad;
187 *pp++ = val, cp++;
188 } else
189 break;
190 }
191 /*
192 * Check for trailing characters.
193 */
194 if (*cp != '\0')
195 goto bad;
196
197 /*
198 * Concoct the address according to
199 * the number of parts specified.
200 */
201 n = pp - parts + 1;
202 switch (n) {
203
204 case 1: /* a -- 32 bits */
205 break;
206
207 case 2: /* a.b -- 8.24 bits */
208 if (val > 0xffffff)
209 goto bad;
210 val |= parts[0] << 24;
211 break;
212
213 case 3: /* a.b.c -- 8.8.16 bits */
214 if (val > 0xffff)
215 goto bad;
216 val |= (parts[0] << 24) | (parts[1] << 16);
217 break;
218
219 case 4: /* a.b.c.d -- 8.8.8.8 bits */
220 if (val > 0xff)
221 goto bad;
222 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
223 break;
224 }
225
226 return (htonl(val));
227 bad:
228 return (htonl(INADDR_NONE));
229 }
230
231 char *
inet_ntoa(struct in_addr ia)232 inet_ntoa(struct in_addr ia)
233 {
234 return (intoa(ia.s_addr));
235 }
236
237 /* Similar to inet_ntoa() */
238 char *
intoa(n_long addr)239 intoa(n_long addr)
240 {
241 char *cp;
242 u_int byte;
243 int n;
244 static char buf[17]; /* strlen(".255.255.255.255") + 1 */
245
246 addr = ntohl(addr);
247 cp = &buf[sizeof buf];
248 *--cp = '\0';
249
250 n = 4;
251 do {
252 byte = addr & 0xff;
253 *--cp = byte % 10 + '0';
254 byte /= 10;
255 if (byte > 0) {
256 *--cp = byte % 10 + '0';
257 byte /= 10;
258 if (byte > 0)
259 *--cp = byte + '0';
260 }
261 *--cp = '.';
262 addr >>= 8;
263 } while (--n > 0);
264
265 return (cp+1);
266 }
267
268 static char *
number(char * s,n_long * n)269 number(char *s, n_long *n)
270 {
271 for (*n = 0; isdigit(*s); s++)
272 *n = (*n * 10) + *s - '0';
273 return s;
274 }
275
276 n_long
ip_convertaddr(char * p)277 ip_convertaddr(char *p)
278 {
279 #define IP_ANYADDR 0
280 n_long addr = 0, n;
281
282 if (p == NULL || *p == '\0')
283 return IP_ANYADDR;
284 p = number(p, &n);
285 addr |= (n << 24) & 0xff000000;
286 if (*p == '\0' || *p++ != '.')
287 return IP_ANYADDR;
288 p = number(p, &n);
289 addr |= (n << 16) & 0xff0000;
290 if (*p == '\0' || *p++ != '.')
291 return IP_ANYADDR;
292 p = number(p, &n);
293 addr |= (n << 8) & 0xff00;
294 if (*p == '\0' || *p++ != '.')
295 return IP_ANYADDR;
296 p = number(p, &n);
297 addr |= n & 0xff;
298 if (*p != '\0')
299 return IP_ANYADDR;
300
301 return htonl(addr);
302 }
303