gd.c

Nessus的应用与漏洞扫描技术的研究

#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include "gd.h"
#include "mtables.c"

static void gdImageBrushApply(gdImagePtr im, int x, int y);
static void gdImageTileApply(gdImagePtr im, int x, int y);

gdImagePtr gdImageCreate(int sx, int sy)
{
	int i;
	gdImagePtr im;
	im = (gdImage *) malloc(sizeof(gdImage));
	/* NOW ROW-MAJOR IN GD 1.3 */
	im->pixels = (unsigned char **) malloc(sizeof(unsigned char *) * sy);
	im->polyInts = 0;
	im->polyAllocated = 0;
	im->brush = 0;
	im->tile = 0;
	im->style = 0;
	for (i=0; (i<sy); i++) {
		/* NOW ROW-MAJOR IN GD 1.3 */
		im->pixels[i] = (unsigned char *) calloc(
			sx, sizeof(unsigned char));
	}	
	im->sx = sx;
	im->sy = sy;
	im->colorsTotal = 0;
	im->transparent = (-1);
	im->interlace = 0;
	return im;
}

void gdImageDestroy(gdImagePtr im)
{
	int i;
	for (i=0; (i<im->sy); i++) {
		free(im->pixels[i]);
	}	
	free(im->pixels);
	if (im->polyInts) {
			free(im->polyInts);
	}
	if (im->style) {
		free(im->style);
	}
	free(im);
}

int gdImageColorClosest(gdImagePtr im, int r, int g, int b)
{
	int i;
	long rd, gd, bd;
	int ct = (-1);
	long mindist = 0;
	for (i=0; (i<(im->colorsTotal)); i++) {
		long dist;
		if (im->open[i]) {
			continue;
		}
		rd = (im->red[i] - r);	
		gd = (im->green[i] - g);
		bd = (im->blue[i] - b);
		dist = rd * rd + gd * gd + bd * bd;
		if ((i == 0) || (dist < mindist)) {
			mindist = dist;	
			ct = i;
		}
	}
	return ct;
}

int gdImageColorExact(gdImagePtr im, int r, int g, int b)
{
	int i;
	for (i=0; (i<(im->colorsTotal)); i++) {
		if (im->open[i]) {
			continue;
		}
		if ((im->red[i] == r) && 
			(im->green[i] == g) &&
			(im->blue[i] == b)) {
			return i;
		}
	}
	return -1;
}

int gdImageColorAllocate(gdImagePtr im, int r, int g, int b)
{
	int i;
	int ct = (-1);
	for (i=0; (i<(im->colorsTotal)); i++) {
		if (im->open[i]) {
			ct = i;
			break;
		}
	}	
	if (ct == (-1)) {
		ct = im->colorsTotal;
		if (ct == gdMaxColors) {
			return -1;
		}
		im->colorsTotal++;
	}
	im->red[ct] = r;
	im->green[ct] = g;
	im->blue[ct] = b;
	im->open[ct] = 0;
	return ct;
}

void gdImageColorDeallocate(gdImagePtr im, int color)
{
	/* Mark it open. */
	im->open[color] = 1;
}

void gdImageColorTransparent(gdImagePtr im, int color)
{
	im->transparent = color;
}

void gdImageSetPixel(gdImagePtr im, int x, int y, int color)
{
	int p;
	switch(color) {
		case gdStyled:
		if (!im->style) {
			/* Refuse to draw if no style is set. */
			return;
		} else {
			p = im->style[im->stylePos++];
		}
		if (p != (gdTransparent)) {
			gdImageSetPixel(im, x, y, p);
		}
		im->stylePos = im->stylePos %  im->styleLength;
		break;
		case gdStyledBrushed:
		if (!im->style) {
			/* Refuse to draw if no style is set. */
			return;
		}
		p = im->style[im->stylePos++];
		if ((p != gdTransparent) && (p != 0)) {
			gdImageSetPixel(im, x, y, gdBrushed);
		}
		im->stylePos = im->stylePos %  im->styleLength;
		break;
		case gdBrushed:
		gdImageBrushApply(im, x, y);
		break;
		case gdTiled:
		gdImageTileApply(im, x, y);
		break;
		default:
		if (gdImageBoundsSafe(im, x, y)) {
			/* NOW ROW-MAJOR IN GD 1.3 */
			im->pixels[y][x] = color;
		}
		break;
	}
}

static void gdImageBrushApply(gdImagePtr im, int x, int y)
{
	int lx, ly;
	int hy;
	int hx;
	int x1, y1, x2, y2;
	int srcx, srcy;
	if (!im->brush) {
		return;
	}
	hy = gdImageSY(im->brush)/2;
	y1 = y - hy;
	y2 = y1 + gdImageSY(im->brush);	
	hx = gdImageSX(im->brush)/2;
	x1 = x - hx;
	x2 = x1 + gdImageSX(im->brush);
	srcy = 0;
	for (ly = y1; (ly < y2); ly++) {
		srcx = 0;
		for (lx = x1; (lx < x2); lx++) {
			int p;
			p = gdImageGetPixel(im->brush, srcx, srcy);
			/* Allow for non-square brushes! */
			if (p != gdImageGetTransparent(im->brush)) {
				gdImageSetPixel(im, lx, ly,
					im->brushColorMap[p]);
			}
			srcx++;
		}
		srcy++;
	}	
}		

static void gdImageTileApply(gdImagePtr im, int x, int y)
{
	int srcx, srcy;
	int p;
	if (!im->tile) {
		return;
	}
	srcx = x % gdImageSX(im->tile);
	srcy = y % gdImageSY(im->tile);
	p = gdImageGetPixel(im->tile, srcx, srcy);
	/* Allow for transparency */
	if (p != gdImageGetTransparent(im->tile)) {
		gdImageSetPixel(im, x, y,
			im->tileColorMap[p]);
	}
}		

int gdImageGetPixel(gdImagePtr im, int x, int y)
{
	if (gdImageBoundsSafe(im, x, y)) {
		/* NOW ROW-MAJOR IN GD 1.3 */
		return im->pixels[y][x];
	} else {
		return 0;
	}
}

/* Bresenham as presented in Foley & Van Dam */

void gdImageLine(gdImagePtr im, int x1, int y1, int x2, int y2, int color)
{
	int dx, dy, incr1, incr2, d, x, y, xend, yend, xdirflag, ydirflag;
	dx = abs(x2-x1);
	dy = abs(y2-y1);
	if (dy <= dx) {
		d = 2*dy - dx;
		incr1 = 2*dy;
		incr2 = 2 * (dy - dx);
		if (x1 > x2) {
			x = x2;
			y = y2;
			ydirflag = (-1);
			xend = x1;
		} else {
			x = x1;
			y = y1;
			ydirflag = 1;
			xend = x2;
		}
		gdImageSetPixel(im, x, y, color);
		if (((y2 - y1) * ydirflag) > 0) {
			while (x < xend) {
				x++;
				if (d <0) {
					d+=incr1;
				} else {
					y++;
					d+=incr2;
				}
				gdImageSetPixel(im, x, y, color);
			}
		} else {
			while (x < xend) {
				x++;
				if (d <0) {
					d+=incr1;
				} else {
					y--;
					d+=incr2;
				}
				gdImageSetPixel(im, x, y, color);
			}
		}		
	} else {
		d = 2*dx - dy;
		incr1 = 2*dx;
		incr2 = 2 * (dx - dy);
		if (y1 > y2) {
			y = y2;
			x = x2;
			yend = y1;
			xdirflag = (-1);
		} else {
			y = y1;
			x = x1;
			yend = y2;
			xdirflag = 1;
		}
		gdImageSetPixel(im, x, y, color);
		if (((x2 - x1) * xdirflag) > 0) {
			while (y < yend) {
				y++;
				if (d <0) {
					d+=incr1;
				} else {
					x++;
					d+=incr2;
				}
				gdImageSetPixel(im, x, y, color);
			}
		} else {
			while (y < yend) {
				y++;
				if (d <0) {
					d+=incr1;
				} else {
					x--;
					d+=incr2;
				}
				gdImageSetPixel(im, x, y, color);
			}
		}
	}
}

static void dashedSet(gdImagePtr im, int x, int y, int color,
	int *onP, int *dashStepP);

void gdImageDashedLine(gdImagePtr im, int x1, int y1, int x2, int y2, int color)
{
	int dx, dy, incr1, incr2, d, x, y, xend, yend, xdirflag, ydirflag;
	int dashStep = 0;
	int on = 1;
	dx = abs(x2-x1);
	dy = abs(y2-y1);
	if (dy <= dx) {
		d = 2*dy - dx;
		incr1 = 2*dy;
		incr2 = 2 * (dy - dx);
		if (x1 > x2) {
			x = x2;
			y = y2;
			ydirflag = (-1);
			xend = x1;
		} else {
			x = x1;
			y = y1;
			ydirflag = 1;
			xend = x2;
		}
		dashedSet(im, x, y, color, &on, &dashStep);
		if (((y2 - y1) * ydirflag) > 0) {
			while (x < xend) {
				x++;
				if (d <0) {
					d+=incr1;
				} else {
					y++;
					d+=incr2;
				}
				dashedSet(im, x, y, color, &on, &dashStep);
			}
		} else {
			while (x < xend) {
				x++;
				if (d <0) {
					d+=incr1;
				} else {
					y--;
					d+=incr2;
				}
				dashedSet(im, x, y, color, &on, &dashStep);
			}
		}		
	} else {
		d = 2*dx - dy;
		incr1 = 2*dx;
		incr2 = 2 * (dx - dy);
		if (y1 > y2) {
			y = y2;
			x = x2;
			yend = y1;
			xdirflag = (-1);
		} else {
			y = y1;
			x = x1;
			yend = y2;
			xdirflag = 1;
		}
		dashedSet(im, x, y, color, &on, &dashStep);
		if (((x2 - x1) * xdirflag) > 0) {
			while (y < yend) {
				y++;
				if (d <0) {
					d+=incr1;
				} else {
					x++;
					d+=incr2;
				}
				dashedSet(im, x, y, color, &on, &dashStep);
			}
		} else {
			while (y < yend) {
				y++;
				if (d <0) {
					d+=incr1;
				} else {
					x--;
					d+=incr2;
				}
				dashedSet(im, x, y, color, &on, &dashStep);
			}
		}
	}
}

static void dashedSet(gdImagePtr im, int x, int y, int color,
	int *onP, int *dashStepP)
{
	int dashStep = *dashStepP;
	int on = *onP;
	dashStep++;
	if (dashStep == gdDashSize) {
		dashStep = 0;
		on = !on;
	}
	if (on) {
		gdImageSetPixel(im, x, y, color);
	}
	*dashStepP = dashStep;
	*onP = on;
}
	

int gdImageBoundsSafe(gdImagePtr im, int x, int y)
{
	return (!(((y < 0) || (y >= im->sy)) ||
		((x < 0) || (x >= im->sx))));
}

void gdImageChar(gdImagePtr im, gdFontPtr f, int x, int y, 
	int c, int color)
{
	int cx, cy;
	int px, py;
	int fline;
	cx = 0;
	cy = 0;
	if ((c < f->offset) || (c >= (f->offset + f->nchars))) {
		return;
	}
	fline = (c - f->offset) * f->h * f->w;
	for (py = y; (py < (y + f->h)); py++) {
		for (px = x; (px < (x + f->w)); px++) {
			if (f->data[fline + cy * f->w + cx]) {
				gdImageSetPixel(im, px, py, color);	
			}
			cx++;
		}
		cx = 0;
		cy++;
	}
}

void gdImageCharUp(gdImagePtr im, gdFontPtr f, 
	int x, int y, int c, int color)
{
	int cx, cy;
	int px, py;
	int fline;
	cx = 0;
	cy = 0;
	if ((c < f->offset) || (c >= (f->offset + f->nchars))) {
		return;
	}
	fline = (c - f->offset) * f->h * f->w;
	for (py = y; (py > (y - f->w)); py--) {
		for (px = x; (px < (x + f->h)); px++) {
			if (f->data[fline + cy * f->w + cx]) {
				gdImageSetPixel(im, px, py, color);	
			}
			cy++;
		}
		cy = 0;
		cx++;
	}
}

void gdImageString(gdImagePtr im, gdFontPtr f, 
	int x, int y, unsigned char *s, int color)
{
	int i;
	int l;
	l = strlen((char*)s);
	for (i=0; (i<l); i++) {
		gdImageChar(im, f, x, y, s[i], color);
		x += f->w;
	}
}

void gdImageStringUp(gdImagePtr im, gdFontPtr f, 
	int x, int y, unsigned char *s, int color)
{
	int i;
	int l;
	l = strlen((char*)s);
	for (i=0; (i<l); i++) {
		gdImageCharUp(im, f, x, y, s[i], color);
		y -= f->w;
	}
}

static int strlen16(unsigned short *s);

void gdImageString16(gdImagePtr im, gdFontPtr f, 
	int x, int y, unsigned short *s, int color)
{
	int i;
	int l;
	l = strlen16(s);
	for (i=0; (i<l); i++) {
		gdImageChar(im, f, x, y, s[i], color);
		x += f->w;
	}
}

void gdImageStringUp16(gdImagePtr im, gdFontPtr f, 
	int x, int y, unsigned short *s, int color)
{
	int i;
	int l;
	l = strlen16(s);
	for (i=0; (i<l); i++) {
		gdImageCharUp(im, f, x, y, s[i], color);
		y -= f->w;
	}
}

static int strlen16(unsigned short *s)
{
	int len = 0;
	while (*s) {
		s++;
		len++;
	}
	return len;
}

/* s and e are integers modulo 360 (degrees), with 0 degrees
  being the rightmost extreme and degrees changing clockwise.
  cx and cy are the center in pixels; w and h are the horizontal 
  and vertical diameter in pixels. Nice interface, but slow, since
  I don't yet use Bresenham (I'm using an inefficient but
  simple solution with too much work going on in it; generalizing
  Bresenham to ellipses and partial arcs of ellipses is non-trivial,
  at least for me) and there are other inefficiencies (small circles
  do far too much work). */

void gdImageArc(gdImagePtr im, int cx, int cy, int w, int h, int s, int e, int color)
{
	int i;
	int lx = 0, ly = 0;
	int w2, h2;
	w2 = w/2;
	h2 = h/2;
	while (e < s) {
		e += 360;
	}
	for (i=s; (i <= e); i++) {
		int x, y;
		x = ((long)cost[i % 360] * (long)w2 / costScale) + cx; 
		y = ((long)sint[i % 360] * (long)h2 / sintScale) + cy;
		if (i != s) {
			gdImageLine(im, lx, ly, x, y, color);	
		}
		lx = x;
		ly = y;
	}
}


#if 0
	/* Bresenham octant code, which I should use eventually */
	int x, y, d;
	x = 0;
	y = w;
	d = 3-2*w;
	while (x < y) {
		gdImageSetPixel(im, cx+x, cy+y, color);
		if (d < 0) {
			d += 4 * x + 6;
		} else {
			d += 4 * (x - y) + 10;
			y--;
		}
		x++;
	}
	if (x == y) {
		gdImageSetPixel(im, cx+x, cy+y, color);
	}
#endif

void gdImageFillToBorder(gdImagePtr im, int x, int y, int border, int color)
{
	int lastBorder;
	/* Seek left */
	int leftLimit, rightLimit;
	int i;
	leftLimit = (-1);
	if (border < 0) {
		/* Refuse to fill to a non-solid border */
		return;
	}
	for (i = x; (i >= 0); i--) {
		if (gdImageGetPixel(im, i, y) == border) {
			break;
		}
		gdImageSetPixel(im, i, y, color);
		leftLimit = i;
	}
	if (leftLimit == (-1)) {
		return;
	}
	/* Seek right */
	rightLimit = x;
	for (i = (x+1); (i < im->sx); i++) {	
		if (gdImageGetPixel(im, i, y) == border) {
			break;
		}
		gdImageSetPixel(im, i, y, color);
		rightLimit = i;
	}
	/* Look at lines above and below and start paints */
	/* Above */
	if (y > 0) {
		lastBorder = 1;
		for (i = leftLimit; (i <= rightLimit); i++) {
			int c;
			c = gdImageGetPixel(im, i, y-1);
			if (lastBorder) {
				if ((c != border) && (c != color)) {	
					gdImageFillToBorder(im, i, y-1, 
						border, color);		
					lastBorder = 0;
				}
			} else if ((c == border) || (c == color)) {
				lastBorder = 1;
			}
		}
	}
	/* Below */
	if (y < ((im->sy) - 1)) {
		lastBorder = 1;
		for (i = leftLimit; (i <= rightLimit); i++) {
			int c;
			c = gdImageGetPixel(im, i, y+1);
			if (lastBorder) {
				if ((c != border) && (c != color)) {	
					gdImageFillToBorder(im, i, y+1, 
						border, color);		
					lastBorder = 0;
				}
			} else if ((c == border) || (c == color)) {
				lastBorder = 1;
			}
		}
	}
}