/* Some systems (e.g., SunOS) have header files that erroneously declare
* inet_addr(), inet_ntoa() and gethostbyname() as taking no arguments.
* This confuses C++. To overcome this, we use our own routines,
* implemented in C.
*/
#ifndef _NET_COMMON_H
#include "NetCommon.h"
#endif
#include <stdio.h>
#ifdef VXWORKS
#include <inetLib.h>
#endif
unsigned our_inet_addr(cp)
char const* cp;
{
return inet_addr(cp);
}
char *
our_inet_ntoa(in)
struct in_addr in;
{
#ifndef VXWORKS
return inet_ntoa(in);
#else
/* according the man pages of inet_ntoa :
NOTES
The return value from inet_ntoa() points to a buffer which
is overwritten on each call. This buffer is implemented as
thread-specific data in multithreaded applications.
the vxworks version of inet_ntoa allocates a buffer for each
ip address string, and does not reuse the same buffer.
this is merely to simulate the same behaviour (not multithread
safe though):
*/
static char result[INET_ADDR_LEN];
inet_ntoa_b(in, result);
return(result);
#endif
}
#if defined(__WIN32__) || defined(_WIN32)
#ifndef IMN_PIM
#define WS_VERSION_CHOICE1 0x202/*MAKEWORD(2,2)*/
#define WS_VERSION_CHOICE2 0x101/*MAKEWORD(1,1)*/
int initializeWinsockIfNecessary(void) {
/* We need to call an initialization routine before
* we can do anything with winsock. (How fucking lame!):
*/
static int _haveInitializedWinsock = 0;
WSADATA wsadata;
if (!_haveInitializedWinsock) {
if ((WSAStartup(WS_VERSION_CHOICE1, &wsadata) != 0)
&& ((WSAStartup(WS_VERSION_CHOICE2, &wsadata)) != 0)) {
return 0; /* error in initialization */
}
if ((wsadata.wVersion != WS_VERSION_CHOICE1)
&& (wsadata.wVersion != WS_VERSION_CHOICE2)) {
WSACleanup();
return 0; /* desired Winsock version was not available */
}
_haveInitializedWinsock = 1;
}
return 1;
}
#else
int initializeWinsockIfNecessary(void) { return 1; }
#endif
#else
#define initializeWinsockIfNecessary() 1
#endif
#ifndef NULL
#define NULL 0
#endif
#if !defined(VXWORKS)
struct hostent* our_gethostbyname(name)
char* name;
{
if (!initializeWinsockIfNecessary()) return NULL;
return (struct hostent*) gethostbyname(name);
}
#endif
#ifdef USE_SYSTEM_RANDOM
#include <stdlib.h>
long our_random() {
#if defined(__WIN32__) || defined(_WIN32)
return rand();
#else
return random();
#endif
}
void our_srandom(unsigned int x) {
#if defined(__WIN32__) || defined(_WIN32)
return srand(x);
#else
return srandom(x);
#endif
}
#else
/*
* random.c:
*
* An improved random number generation package. In addition to the standard
* rand()/srand() like interface, this package also has a special state info
* interface. The our_initstate() routine is called with a seed, an array of
* bytes, and a count of how many bytes are being passed in; this array is
* then initialized to contain information for random number generation with
* that much state information. Good sizes for the amount of state
* information are 32, 64, 128, and 256 bytes. The state can be switched by
* calling the our_setstate() routine with the same array as was initiallized
* with our_initstate(). By default, the package runs with 128 bytes of state
* information and generates far better random numbers than a linear
* congruential generator. If the amount of state information is less than
* 32 bytes, a simple linear congruential R.N.G. is used.
*
* Internally, the state information is treated as an array of longs; the
* zeroeth element of the array is the type of R.N.G. being used (small
* integer); the remainder of the array is the state information for the
* R.N.G. Thus, 32 bytes of state information will give 7 longs worth of
* state information, which will allow a degree seven polynomial. (Note:
* the zeroeth word of state information also has some other information
* stored in it -- see our_setstate() for details).
*
* The random number generation technique is a linear feedback shift register
* approach, employing trinomials (since there are fewer terms to sum up that
* way). In this approach, the least significant bit of all the numbers in
* the state table will act as a linear feedback shift register, and will
* have period 2^deg - 1 (where deg is the degree of the polynomial being
* used, assuming that the polynomial is irreducible and primitive). The
* higher order bits will have longer periods, since their values are also
* influenced by pseudo-random carries out of the lower bits. The total
* period of the generator is approximately deg*(2**deg - 1); thus doubling
* the amount of state information has a vast influence on the period of the
* generator. Note: the deg*(2**deg - 1) is an approximation only good for
* large deg, when the period of the shift register is the dominant factor.
* With deg equal to seven, the period is actually much longer than the
* 7*(2**7 - 1) predicted by this formula.
*/
/*
* For each of the currently supported random number generators, we have a
* break value on the amount of state information (you need at least this
* many bytes of state info to support this random number generator), a degree
* for the polynomial (actually a trinomial) that the R.N.G. is based on, and
* the separation between the two lower order coefficients of the trinomial.
*/
#define TYPE_0 0 /* linear congruential */
#define BREAK_0 8
#define DEG_0 0
#define SEP_0 0
#define TYPE_1 1 /* x**7 + x**3 + 1 */
#define BREAK_1 32
#define DEG_1 7
#define SEP_1 3
#define TYPE_2 2 /* x**15 + x + 1 */
#define BREAK_2 64
#define DEG_2 15
#define SEP_2 1
#define TYPE_3 3 /* x**31 + x**3 + 1 */
#define BREAK_3 128
#define DEG_3 31
#define SEP_3 3
#define TYPE_4 4 /* x**63 + x + 1 */
#define BREAK_4 256
#define DEG_4 63
#define SEP_4 1
/*
* Array versions of the above information to make code run faster --
* relies on fact that TYPE_i == i.
*/
#define MAX_TYPES 5 /* max number of types above */
static int const degrees[MAX_TYPES] = { DEG_0, DEG_1, DEG_2, DEG_3, DEG_4 };
static int const seps [MAX_TYPES] = { SEP_0, SEP_1, SEP_2, SEP_3, SEP_4 };
/*
* Initially, everything is set up as if from:
*
* our_initstate(1, &randtbl, 128);
*
* Note that this initialization takes advantage of the fact that srandom()
* advances the front and rear pointers 10*rand_deg times, and hence the
* rear pointer which starts at 0 will also end up at zero; thus the zeroeth
* element of the state information, which contains info about the current
* position of the rear pointer is just
*
* MAX_TYPES * (rptr - state) + TYPE_3 == TYPE_3.
*/
static long randtbl[DEG_3 + 1] = {
TYPE_3,
0x9a319039, 0x32d9c024, 0x9b663182, 0x5da1f342, 0xde3b81e0, 0xdf0a6fb5,
0xf103bc02, 0x48f340fb, 0x7449e56b, 0xbeb1dbb0, 0xab5c5918, 0x946554fd,
0x8c2e680f, 0xeb3d799f, 0xb11ee0b7, 0x2d436b86, 0xda672e2a, 0x1588ca88,
0xe369735d, 0x904f35f7, 0xd7158fd6, 0x6fa6f051, 0x616e6b96, 0xac94efdc,
0x36413f93, 0xc622c298, 0xf5a42ab8, 0x8a88d77b, 0xf5ad9d0e, 0x8999220b,
0x27fb47b9,
};
/*
* fptr and rptr are two pointers into the state info, a front and a rear
* pointer. These two pointers are always rand_sep places aparts, as they
* cycle cyclically through the state information. (Yes, this does mean we
* could get away with just one pointer, but the code for random() is more
* efficient this way). The pointers are left positioned as they would be
* from the call
*
* our_initstate(1, randtbl, 128);
*
* (The position of the rear pointer, rptr, is really 0 (as explained above
* in the initialization of randtbl) because the state table pointer is set
* to point to randtbl[1] (as explained below).
*/
static long* fptr = &randtbl[SEP_3 + 1];
static long* rptr = &randtbl[1];
/*
* The following things are the pointer to the state information table, the
* type of the current generator, the degree of the current polynomial being
* used, and the separation between the two pointers. Note that for efficiency
* of random(), we remember the first location of the state information, not
* the zeroeth. Hence it is valid to access state[-1], which is used to
* store the type of the R.N.G. Also, we remember the last location, since
* this is more efficient than indexing every time to find the address of
* the last element to see if the front and rear pointers have wrapped.
*/
static long *state = &randtbl[1];
static int rand_type = TYPE_3;
static int rand_deg = DEG_3;
static int rand_sep = SEP_3;
static long* end_ptr = &randtbl[DEG_3 + 1];
/*
* srandom:
*
* Initialize the random number generator based on the given seed. If the
* type is the trivial no-state-information type, just remember the seed.
* Otherwise, initializes state[] based on the given "seed" via a linear
* congruential generator. Then, the pointers are set to known locations
* that are exactly rand_sep places apart. Lastly, it cycles the state
* information a given number of times to get rid of any initial dependencies
* introduced by the L.C.R.N.G. Note that the initialization of randtbl[]
* for default usage relies on values produced by this routine.
*/
long our_random(void); /*forward*/
void
our_srandom(unsigned int x)
{
register int i;
if (rand_type == TYPE_0)
state[0] = x;
else {
state[0] = x;
for (i = 1; i < rand_deg; i++)
state[i] = 1103515245 * state[i - 1] + 12345;
fptr = &state[rand_sep];
rptr = &state[0];
for (i = 0; i < 10 * rand_deg; i++)
(void)our_random();
}
}
/*
* our_initstate:
*
* Initialize the state information in the given array of n bytes for future
* random number generation. Based on the number of bytes we are given, and
* the break values for the different R.N.G.'s, we choose the best (largest)
* one we can and set things up for it. srandom() is then called to
* initialize the state information.
*
* Note that on return from srandom(), we set state[-1] to be the type
* multiplexed with the current value of the rear pointer; this is so
* successive calls to our_initstate() won't lose this information and will be
* able to restart with our_setstate().
*
* Note: the first thing we do is save the current state, if any, just like
* our_setstate() so that it doesn't matter when our_initstate is called.
*
* Returns a pointer to the old state.
*/
char *
our_initstate(seed, arg_state, n)
unsigned int seed; /* seed for R.N.G. */
char *arg_state; /* pointer to state array */
int n; /* # bytes of state info */
{
register char *ostate = (char *)(&state[-1]);
if (rand_type == TYPE_0)
state[-1] = rand_type;
else
state[-1] = MAX_TYPES * (rptr - state) + rand_type;
if (n < BREAK_0) {
#ifdef DEBUG
(void)fprintf(stderr,
"random: not enough state (%d bytes); ignored.\n", n);
#endif
return(0);
}
if (n < BREAK_1) {
rand_type = TYPE_0;
rand_deg = DEG_0;
rand_sep = SEP_0;
} else if (n < BREAK_2) {
rand_type = TYPE_1;
rand_deg = DEG_1;
rand_sep = SEP_1;
} else if (n < BREAK_3) {
rand_type = TYPE_2;
rand_deg = DEG_2;
rand_sep = SEP_2;
} else if (n < BREAK_4) {
rand_type = TYPE_3;
rand_deg = DEG_3;
rand_sep = SEP_3;
} else {
rand_type = TYPE_4;
rand_deg = DEG_4;
rand_sep = SEP_4;
}
state = &(((long *)arg_state)[1]); /* first location */
end_ptr = &state[rand_deg]; /* must set end_ptr before srandom */
our_srandom(seed);
if (rand_type == TYPE_0)
state[-1] = rand_type;
else
state[-1] = MAX_TYPES*(rptr - state) + rand_type;
return(ostate);
}
/*
* our_setstate:
*
* Restore the state from the given state array.
*
* Note: it is important that we also remember the locations of the pointers
* in the current state information, and restore the locations of the pointers
* from the old state information. This is done by multiplexing the pointer
* location into the zeroeth word of the state information.
*
* Note that due to the order in which things are done, it is OK to call
* our_setstate() with the same state as the current state.
*
* Returns a pointer to the old state information.
*/
char *
our_setstate(arg_state)
char *arg_state;
{
register long *new_state = (long *)arg_state;
register int type = new_state[0] % MAX_TYPES;
register int rear = new_state[0] / MAX_TYPES;
char *ostate = (char *)(&state[-1]);
if (rand_type == TYPE_0)
state[-1] = rand_type;
else
state[-1] = MAX_TYPES * (rptr - state) + rand_type;
switch(type) {
case TYPE_0:
case TYPE_1:
case TYPE_2:
case TYPE_3:
case TYPE_4:
rand_type = type;
rand_deg = degrees[type];
rand_sep = seps[type];
break;
default:
#ifdef DEBUG
(void)fprintf(stderr,
"random: state info corrupted; not changed.\n");
#endif
break;
}
state = &new_state[1];
if (rand_type != TYPE_0) {
rptr = &state[rear];
fptr = &state[(rear + rand_sep) % rand_deg];
}
end_ptr = &state[rand_deg]; /* set end_ptr too */
return(ostate);
}
/*
* random:
*
* If we are using the trivial TYPE_0 R.N.G., just do the old linear
* congruential bit. Otherwise, we do our fancy trinomial stuff, which is
* the same in all the other cases due to all the global variables that have
* been set up. The basic operation is to add the number at the rear pointer
* into the one at the front pointer. Then both pointers are advanced to
* the next location cyclically in the table. The value returned is the sum
* generated, reduced to 31 bits by throwing away the "least random" low bit.
*
* Note: the code takes advantage of the fact that both the front and
* rear pointers can't wrap on the same call by not testing the rear
* pointer if the front one has wrapped.
*
* Returns a 31-bit random number.
*/
long
our_random()
{
long i;
if (rand_type == TYPE_0)
i = state[0] = (state[0] * 1103515245 + 12345) & 0x7fffffff;
else {
*fptr += *rptr;
i = (*fptr >> 1) & 0x7fffffff; /* chucking least random bit */
if (++fptr >= end_ptr) {
fptr = state;
++rptr;
} else if (++rptr >= end_ptr)
rptr = state;
}
return(i);
}
#endif
u_int32_t our_random32() {
// Return a 32-bit random number.
// Because "our_random()" returns a 31-bit random number, we call it a second
// time, to generate the high bit:
long random1 = our_random();
long random2 = our_random();
return (u_int32_t)((random2<<31) | random1);
}
#ifdef USE_OUR_BZERO
#ifndef __bzero
void
__bzero (to, count)
char *to;
int count;
{
while (count-- > 0)
{
*to++ = 0;
}
}
#endif
#endif
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