1#ifndef _NET_COMMON_H
2#include "NetCommon.h"
3#endif
4
5#include <stdio.h>
6
7#ifdef VXWORKS
8#include <inetLib.h>
9#endif
10
11/* Some systems (e.g., SunOS) have header files that erroneously declare inet_addr() as taking no arguments.
12 * This confuses C++. To overcome this, we use our own routine, implemented in C.
13 */
14
15unsigned our_inet_addr(cp)
16 char const* cp;
17{
18 return inet_addr(cp);
19}
20
21#if defined(__WIN32__) || defined(_WIN32)
22#ifndef IMN_PIM
23#define WS_VERSION_CHOICE1 0x202/*MAKEWORD(2,2)*/
24#define WS_VERSION_CHOICE2 0x101/*MAKEWORD(1,1)*/
25int initializeWinsockIfNecessary(void) {
26 /* We need to call an initialization routine before
27 * we can do anything with winsock. (How fucking lame!):
28 */
29 static int _haveInitializedWinsock = 0;
30 WSADATA wsadata;
31
32 if (!_haveInitializedWinsock) {
33 if ((WSAStartup(WS_VERSION_CHOICE1, &wsadata) != 0)
34 && ((WSAStartup(WS_VERSION_CHOICE2, &wsadata)) != 0)) {
35 return 0; /* error in initialization */
36 }
37 if ((wsadata.wVersion != WS_VERSION_CHOICE1)
38 && (wsadata.wVersion != WS_VERSION_CHOICE2)) {
39 WSACleanup();
40 return 0; /* desired Winsock version was not available */
41 }
42 _haveInitializedWinsock = 1;
43 }
44
45 return 1;
46}
47#else
48int initializeWinsockIfNecessary(void) { return 1; }
49#endif
50#else
51#define initializeWinsockIfNecessary() 1
52#endif
53
54#ifndef NULL
55#define NULL 0
56#endif
57
58#ifdef USE_SYSTEM_RANDOM
59/* Use the system-supplied "random()" and "srandom()" functions */
60#include <stdlib.h>
61long our_random() {
62#if defined(__WIN32__) || defined(_WIN32)
63 return rand();
64#else
65 return random();
66#endif
67}
68void our_srandom(unsigned int x) {
69#if defined(__WIN32__) || defined(_WIN32)
70 srand(x);
71#else
72 srandom(x);
73#endif
74}
75
76#else
77
78/* Use our own implementation of the "random()" and "srandom()" functions */
79/*
80 * random.c:
81 *
82 * An improved random number generation package. In addition to the standard
83 * rand()/srand() like interface, this package also has a special state info
84 * interface. The our_initstate() routine is called with a seed, an array of
85 * bytes, and a count of how many bytes are being passed in; this array is
86 * then initialized to contain information for random number generation with
87 * that much state information. Good sizes for the amount of state
88 * information are 32, 64, 128, and 256 bytes. The state can be switched by
89 * calling the our_setstate() routine with the same array as was initiallized
90 * with our_initstate(). By default, the package runs with 128 bytes of state
91 * information and generates far better random numbers than a linear
92 * congruential generator. If the amount of state information is less than
93 * 32 bytes, a simple linear congruential R.N.G. is used.
94 *
95 * Internally, the state information is treated as an array of longs; the
96 * zeroeth element of the array is the type of R.N.G. being used (small
97 * integer); the remainder of the array is the state information for the
98 * R.N.G. Thus, 32 bytes of state information will give 7 longs worth of
99 * state information, which will allow a degree seven polynomial. (Note:
100 * the zeroeth word of state information also has some other information
101 * stored in it -- see our_setstate() for details).
102 *
103 * The random number generation technique is a linear feedback shift register
104 * approach, employing trinomials (since there are fewer terms to sum up that
105 * way). In this approach, the least significant bit of all the numbers in
106 * the state table will act as a linear feedback shift register, and will
107 * have period 2^deg - 1 (where deg is the degree of the polynomial being
108 * used, assuming that the polynomial is irreducible and primitive). The
109 * higher order bits will have longer periods, since their values are also
110 * influenced by pseudo-random carries out of the lower bits. The total
111 * period of the generator is approximately deg*(2**deg - 1); thus doubling
112 * the amount of state information has a vast influence on the period of the
113 * generator. Note: the deg*(2**deg - 1) is an approximation only good for
114 * large deg, when the period of the shift register is the dominant factor.
115 * With deg equal to seven, the period is actually much longer than the
116 * 7*(2**7 - 1) predicted by this formula.
117 */
118
119/*
120 * For each of the currently supported random number generators, we have a
121 * break value on the amount of state information (you need at least this
122 * many bytes of state info to support this random number generator), a degree
123 * for the polynomial (actually a trinomial) that the R.N.G. is based on, and
124 * the separation between the two lower order coefficients of the trinomial.
125 */
126#define TYPE_0 0 /* linear congruential */
127#define BREAK_0 8
128#define DEG_0 0
129#define SEP_0 0
130
131#define TYPE_1 1 /* x**7 + x**3 + 1 */
132#define BREAK_1 32
133#define DEG_1 7
134#define SEP_1 3
135
136#define TYPE_2 2 /* x**15 + x + 1 */
137#define BREAK_2 64
138#define DEG_2 15
139#define SEP_2 1
140
141#define TYPE_3 3 /* x**31 + x**3 + 1 */
142#define BREAK_3 128
143#define DEG_3 31
144#define SEP_3 3
145
146#define TYPE_4 4 /* x**63 + x + 1 */
147#define BREAK_4 256
148#define DEG_4 63
149#define SEP_4 1
150
151/*
152 * Array versions of the above information to make code run faster --
153 * relies on fact that TYPE_i == i.
154 */
155#define MAX_TYPES 5 /* max number of types above */
156
157static int const degrees[MAX_TYPES] = { DEG_0, DEG_1, DEG_2, DEG_3, DEG_4 };
158static int const seps [MAX_TYPES] = { SEP_0, SEP_1, SEP_2, SEP_3, SEP_4 };
159
160/*
161 * Initially, everything is set up as if from:
162 *
163 * our_initstate(1, &randtbl, 128);
164 *
165 * Note that this initialization takes advantage of the fact that srandom()
166 * advances the front and rear pointers 10*rand_deg times, and hence the
167 * rear pointer which starts at 0 will also end up at zero; thus the zeroeth
168 * element of the state information, which contains info about the current
169 * position of the rear pointer is just
170 *
171 * MAX_TYPES * (rptr - state) + TYPE_3 == TYPE_3.
172 */
173
174static long randtbl[DEG_3 + 1] = {
175 TYPE_3,
176 0x9a319039, 0x32d9c024, 0x9b663182, 0x5da1f342, 0xde3b81e0, 0xdf0a6fb5,
177 0xf103bc02, 0x48f340fb, 0x7449e56b, 0xbeb1dbb0, 0xab5c5918, 0x946554fd,
178 0x8c2e680f, 0xeb3d799f, 0xb11ee0b7, 0x2d436b86, 0xda672e2a, 0x1588ca88,
179 0xe369735d, 0x904f35f7, 0xd7158fd6, 0x6fa6f051, 0x616e6b96, 0xac94efdc,
180 0x36413f93, 0xc622c298, 0xf5a42ab8, 0x8a88d77b, 0xf5ad9d0e, 0x8999220b,
181 0x27fb47b9,
182};
183
184/*
185 * fptr and rptr are two pointers into the state info, a front and a rear
186 * pointer. These two pointers are always rand_sep places aparts, as they
187 * cycle cyclically through the state information. (Yes, this does mean we
188 * could get away with just one pointer, but the code for random() is more
189 * efficient this way). The pointers are left positioned as they would be
190 * from the call
191 *
192 * our_initstate(1, randtbl, 128);
193 *
194 * (The position of the rear pointer, rptr, is really 0 (as explained above
195 * in the initialization of randtbl) because the state table pointer is set
196 * to point to randtbl[1] (as explained below).
197 */
198static long* fptr = &randtbl[SEP_3 + 1];
199static long* rptr = &randtbl[1];
200
201/*
202 * The following things are the pointer to the state information table, the
203 * type of the current generator, the degree of the current polynomial being
204 * used, and the separation between the two pointers. Note that for efficiency
205 * of random(), we remember the first location of the state information, not
206 * the zeroeth. Hence it is valid to access state[-1], which is used to
207 * store the type of the R.N.G. Also, we remember the last location, since
208 * this is more efficient than indexing every time to find the address of
209 * the last element to see if the front and rear pointers have wrapped.
210 */
211static long *state = &randtbl[1];
212static int rand_type = TYPE_3;
213static int rand_deg = DEG_3;
214static int rand_sep = SEP_3;
215static long* end_ptr = &randtbl[DEG_3 + 1];
216
217/*
218 * srandom:
219 *
220 * Initialize the random number generator based on the given seed. If the
221 * type is the trivial no-state-information type, just remember the seed.
222 * Otherwise, initializes state[] based on the given "seed" via a linear
223 * congruential generator. Then, the pointers are set to known locations
224 * that are exactly rand_sep places apart. Lastly, it cycles the state
225 * information a given number of times to get rid of any initial dependencies
226 * introduced by the L.C.R.N.G. Note that the initialization of randtbl[]
227 * for default usage relies on values produced by this routine.
228 */
229long our_random(void); /*forward*/
230void
231our_srandom(unsigned int x)
232{
233 register int i;
234
235 if (rand_type == TYPE_0)
236 state[0] = x;
237 else {
238 state[0] = x;
239 for (i = 1; i < rand_deg; i++)
240 state[i] = 1103515245 * state[i - 1] + 12345;
241 fptr = &state[rand_sep];
242 rptr = &state[0];
243 for (i = 0; i < 10 * rand_deg; i++)
244 (void)our_random();
245 }
246}
247
248/*
249 * our_initstate:
250 *
251 * Initialize the state information in the given array of n bytes for future
252 * random number generation. Based on the number of bytes we are given, and
253 * the break values for the different R.N.G.'s, we choose the best (largest)
254 * one we can and set things up for it. srandom() is then called to
255 * initialize the state information.
256 *
257 * Note that on return from srandom(), we set state[-1] to be the type
258 * multiplexed with the current value of the rear pointer; this is so
259 * successive calls to our_initstate() won't lose this information and will be
260 * able to restart with our_setstate().
261 *
262 * Note: the first thing we do is save the current state, if any, just like
263 * our_setstate() so that it doesn't matter when our_initstate is called.
264 *
265 * Returns a pointer to the old state.
266 */
267char *
268our_initstate(seed, arg_state, n)
269 unsigned int seed; /* seed for R.N.G. */
270 char *arg_state; /* pointer to state array */
271 int n; /* # bytes of state info */
272{
273 register char *ostate = (char *)(&state[-1]);
274
275 if (rand_type == TYPE_0)
276 state[-1] = rand_type;
277 else
278 state[-1] = MAX_TYPES * (rptr - state) + rand_type;
279 if (n < BREAK_0) {
280#ifdef DEBUG
281 (void)fprintf(stderr,
282 "random: not enough state (%d bytes); ignored.\n", n);
283#endif
284 return(0);
285 }
286 if (n < BREAK_1) {
287 rand_type = TYPE_0;
288 rand_deg = DEG_0;
289 rand_sep = SEP_0;
290 } else if (n < BREAK_2) {
291 rand_type = TYPE_1;
292 rand_deg = DEG_1;
293 rand_sep = SEP_1;
294 } else if (n < BREAK_3) {
295 rand_type = TYPE_2;
296 rand_deg = DEG_2;
297 rand_sep = SEP_2;
298 } else if (n < BREAK_4) {
299 rand_type = TYPE_3;
300 rand_deg = DEG_3;
301 rand_sep = SEP_3;
302 } else {
303 rand_type = TYPE_4;
304 rand_deg = DEG_4;
305 rand_sep = SEP_4;
306 }
307 state = &(((long *)arg_state)[1]); /* first location */
308 end_ptr = &state[rand_deg]; /* must set end_ptr before srandom */
309 our_srandom(seed);
310 if (rand_type == TYPE_0)
311 state[-1] = rand_type;
312 else
313 state[-1] = MAX_TYPES*(rptr - state) + rand_type;
314 return(ostate);
315}
316
317/*
318 * our_setstate:
319 *
320 * Restore the state from the given state array.
321 *
322 * Note: it is important that we also remember the locations of the pointers
323 * in the current state information, and restore the locations of the pointers
324 * from the old state information. This is done by multiplexing the pointer
325 * location into the zeroeth word of the state information.
326 *
327 * Note that due to the order in which things are done, it is OK to call
328 * our_setstate() with the same state as the current state.
329 *
330 * Returns a pointer to the old state information.
331 */
332char *
333our_setstate(arg_state)
334 char *arg_state;
335{
336 register long *new_state = (long *)arg_state;
337 register int type = new_state[0] % MAX_TYPES;
338 register int rear = new_state[0] / MAX_TYPES;
339 char *ostate = (char *)(&state[-1]);
340
341 if (rand_type == TYPE_0)
342 state[-1] = rand_type;
343 else
344 state[-1] = MAX_TYPES * (rptr - state) + rand_type;
345 switch(type) {
346 case TYPE_0:
347 case TYPE_1:
348 case TYPE_2:
349 case TYPE_3:
350 case TYPE_4:
351 rand_type = type;
352 rand_deg = degrees[type];
353 rand_sep = seps[type];
354 break;
355 default:
356#ifdef DEBUG
357 (void)fprintf(stderr,
358 "random: state info corrupted; not changed.\n");
359#endif
360 break;
361 }
362 state = &new_state[1];
363 if (rand_type != TYPE_0) {
364 rptr = &state[rear];
365 fptr = &state[(rear + rand_sep) % rand_deg];
366 }
367 end_ptr = &state[rand_deg]; /* set end_ptr too */
368 return(ostate);
369}
370
371/*
372 * random:
373 *
374 * If we are using the trivial TYPE_0 R.N.G., just do the old linear
375 * congruential bit. Otherwise, we do our fancy trinomial stuff, which is
376 * the same in all the other cases due to all the global variables that have
377 * been set up. The basic operation is to add the number at the rear pointer
378 * into the one at the front pointer. Then both pointers are advanced to
379 * the next location cyclically in the table. The value returned is the sum
380 * generated, reduced to 31 bits by throwing away the "least random" low bit.
381 *
382 * Note: the code takes advantage of the fact that both the front and
383 * rear pointers can't wrap on the same call by not testing the rear
384 * pointer if the front one has wrapped.
385 *
386 * Returns a 31-bit random number.
387 */
388long our_random() {
389 long i;
390
391 if (rand_type == TYPE_0) {
392 i = state[0] = (state[0] * 1103515245 + 12345) & 0x7fffffff;
393 } else {
394 /* Make copies of "rptr" and "fptr" before working with them, in case we're being called concurrently by multiple threads: */
395 long* rp = rptr;
396 long* fp = fptr;
397
398 /* Make sure "rp" and "fp" are separated by the correct distance (again, allowing for concurrent access): */
399 if (!(fp == rp+SEP_3 || fp+DEG_3 == rp+SEP_3)) {
400 /* A rare case that should occur only if we're being called concurrently by multiple threads. */
401 /* Restore the proper separation between the pointers: */
402 if (rp <= fp) rp = fp-SEP_3; else rp = fp+DEG_3-SEP_3;
403 }
404
405 *fp += *rp;
406 i = (*fp >> 1) & 0x7fffffff; /* chucking least random bit */
407 if (++fp >= end_ptr) {
408 fp = state;
409 ++rp;
410 } else if (++rp >= end_ptr) {
411 rp = state;
412 }
413
414 /* Restore "rptr" and "fptr" from our working copies: */
415 rptr = rp;
416 fptr = fp;
417 }
418
419 return i;
420}
421#endif
422
423u_int32_t our_random32() {
424 /* Return a 32-bit random number.
425 Because "our_random()" returns a 31-bit random number, we call it a second
426 time, to generate the high bit.
427 (Actually, to increase the likelhood of randomness, we take the middle 16 bits of two successive calls to "our_random()")
428 */
429 long random_1 = our_random();
430 u_int32_t random16_1 = (u_int32_t)(random_1&0x00FFFF00);
431
432 long random_2 = our_random();
433 u_int32_t random16_2 = (u_int32_t)(random_2&0x00FFFF00);
434
435 return (random16_1<<8) | (random16_2>>8);
436}
437
438#ifdef USE_OUR_BZERO
439#ifndef __bzero
440void
441__bzero (to, count)
442 char *to;
443 int count;
444{
445 while (count-- > 0)
446 {
447 *to++ = 0;
448 }
449}
450#endif
451#endif
452