/xbmc/pvrclients/MediaPortal/lib/live555/groupsock/inet.c
C | 468 lines | 257 code | 35 blank | 176 comment | 42 complexity | 48c1a3f35ecff8b736e48b95d39461ca MD5 | raw file
- /* 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
- #ifndef USE_OUR_RANDOM
- /* Use the system-supplied "random()" and "srandom()" functions */
- #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)
- srand(x);
- #else
- srandom(x);
- #endif
- }
- #else
- /* Use our own implementation of the "random()" and "srandom()" functions */
- /*
- * 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