misc.c

uCLinux下的一个TCP/IP协议栈源码

/* Miscellaneous machine independent utilities
 */
#include <stdio.h>
#include "global.h"
#include "socket.h"
#include "mbuf.h"

char Whitespace[] = " \t\r\n";

/* Select from an array of strings, or return ascii number if out of range */
char *
smsg(msgs,nmsgs,n)
char *msgs[];
unsigned nmsgs,n;
{
	static char buf[16];

	if(n < nmsgs && msgs[n] != NULL)
		return msgs[n];
	sprintf(buf,"%u",n);
	return buf;
}

/* Convert hex-ascii to integer */
int
htoi(s)
char *s;
{
	int i = 0;
	char c;

	while((c = *s++) != '\0'){
		if(c == 'x')
			continue;	/* allow 0x notation */
		if('0' <= c && c <= '9')
			i = (i * 16) + (c - '0');
		else if('a' <= c && c <= 'f')
			i = (i * 16) + (c - 'a' + 10);
		else if('A' <= c && c <= 'F')
			i = (i * 16) + (c - 'A' + 10);
		else
			break;
	}
	return i;
}
/* Convert single hex-ascii character to binary */
int
htob(c)
char c;
{
	if('0' <= c && c <= '9')
		return c - '0';
	else if('a' <= c && c <= 'f')
		return c - 'a' + 10;
	else if('A' <= c && c <= 'F')
		return c - 'A' + 10;
	else
		return -1;
}
/* Read an ascii-encoded hex string, convert to binary and store in
 * output buffer. Return number of bytes converted
 */
int
readhex(out,in,size)
uint8 *out;
char *in;
int size;
{
	int c,count;

	if(in == NULL)
		return 0;
	for(count=0;count < size;count++){
		while(*in == ' ' || *in == '\t')
			in++;	/* Skip white space */
		if((c = htob(*in++)) == -1)
			break;	/* Hit non-hex character */
		out[count] = c << 4;	/* First nybble */
		while(*in == ' ' || *in == '\t')
			in++;	/* Skip white space */
		if((c = htob(*in++)) == -1)
			break;	/* Hit non-hex character */
		out[count] |= c;	/* Second nybble */
	}
	return count;
}
/* replace terminating end of line marker(s) with null */
void
rip(s)
register char *s;
{
	register char *cp;

	if((cp = strchr(s,'\n')) != NULL)
		*cp = '\0';
	if((cp = strchr(s,'\r')) != NULL)
		*cp = '\0';
}
/* Count the occurrances of 'c' in a buffer */
int
memcnt(buf,c,size)
uint8 *buf;
uint8 c;
int size;
{
	int cnt = 0;
	uint8 *icp;

	while(size != 0){
		int change;

		if((icp = memchr(buf,c,size)) == NULL)
			break;	/* No more found */
		/* Advance the start of the next search to right after
		 * this character
		 */
		change = (int) (icp - buf + 1);
		buf += change;
		size -= change;
		cnt++;
	}
	return cnt;
}
/* XOR block 'b' into block 'a' */
void
memxor(a,b,n)
uint8 *a,*b;
unsigned int n;
{
	while(n-- != 0)
		*a++ ^= *b++;
}

/* Copy a string to a malloc'ed buffer. Turbo C has this one in its
 * library, but it doesn't call mallocw() and can therefore return NULL.
 * NOS uses of strdup() generally don't check for NULL, so they need this one.
 */
char *
strdup(s)
const char *s;
{
	register char *out;
	register int len;

	if(s == NULL)
		return NULL;
	len = strlen(s);
	out = mallocw(len+1);
	/* This is probably a tad faster than strcpy, since we know the len */
	memcpy(out,s,len);
	out[len] = '\0';
	return out;
}
/* Routines not needed for Turbo 2.0, but available for older libraries */
#ifdef	AZTEC

/* Case-insensitive string comparison */
strnicmp(a,b,n)
register char *a,*b;
register int n;
{
	char a1,b1;

	while(n-- != 0 && (a1 = *a++) != '\0' && (b1 = *b++) != '\0'){
		if(a1 == b1)
			continue;	/* No need to convert */
		a1 = tolower(a1);
		b1 = tolower(b1);
		if(a1 == b1)
			continue;	/* NOW they match! */
		if(a1 > b1)
			return 1;
		if(a1 < b1)
			return -1;
	}
	return 0;
}

char *
strtok(s1,s2)
char *s1;	/* Source string (first call) or NULL */
#ifdef	__STDC__	/* Ugly kludge for aztec's declaration */
const char *s2;	/* Delimiter string */
#else
char *s2;	/* Delimiter string */
#endif
{
	static int isdelim();
	static char *next;
	register char *cp;
	char *tmp;

	if(s2 == NULL)
		return NULL;	/* Must give delimiter string */

	if(s1 != NULL)
		next = s1;		/* First call */

	if(next == NULL)
		return NULL;	/* No more */

	/* Find beginning of this token */
	for(cp = next;*cp != '\0' && isdelim(*cp,s2);cp++)
		;

	if(*cp == '\0')
		return NULL;	/* Trailing delimiters, no token */

	/* Save the beginning of this token, and find its end */
	tmp = cp;
	next = NULL;	/* In case we don't find another delim */
	for(;*cp != '\0';cp++){
		if(isdelim(*cp,s2)){
			*cp = '\0';
			next = cp + 1;	/* Next call will begin here */
			break;
		}
	}
	return tmp;
}
static int
isdelim(c,delim)
char c;
register char *delim;
{
	char d;

	while((d = *delim++) != '\0'){
		if(c == d)
			return 1;
	}
	return 0;
}
#endif	/* AZTEC */



/* Host-network conversion routines, replaced on the x86 with
 * assembler code in pcgen.asm
 */
#ifndef	MSDOS
/* Put a long in host order into a char array in network order */
uint8 *
put32(cp,x)
register uint8 *cp;
int32 x;
{
	*cp++ = x >> 24;
	*cp++ = x >> 16;
	*cp++ = x >> 8;
	*cp++ = x;
	return cp;
}
/* Put a short in host order into a char array in network order */
uint8 *
put16(cp,x)
register uint8 *cp;
uint16 x;
{
	*cp++ = x >> 8;
	*cp++ = x;

	return cp;
}
uint16
get16(cp)
register uint8 *cp;
{
	register uint16 x;

	x = *cp++;
	x <<= 8;
	x |= *cp;
	return x;
}
/* Machine-independent, alignment insensitive network-to-host long conversion */
int32
get32(cp)
register uint8 *cp;
{
	int32 rval;

	rval = *cp++;
	rval <<= 8;
	rval |= *cp++;
	rval <<= 8;
	rval |= *cp++;
	rval <<= 8;
	rval |= *cp;

	return rval;
}
/* Compute int(log2(x)) */
int
ilog2(x)
register uint16 x;
{
	register int n = 16;
	for(;n != 0;n--){
		if(x & 0x8000)
			break;
		x <<= 1;
	}
	n--;
	return n;
}

#endif