src/buffers.c - haproxy - Gitiles

 /*
  * Buffer management functions.
  *
  * Copyright 2000-2010 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  *
  */

 #include <ctype.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>

 #include <common/config.h>
 #include <common/memory.h>
 #include <proto/buffers.h>
 #include <types/global.h>

 struct pool_head *pool2_buffer;


 /* perform minimal intializations, report 0 in case of error, 1 if OK. */
 int init_buffer()
 {
 	pool2_buffer = create_pool("buffer", sizeof(struct buffer) + global.tune.bufsize, MEM_F_SHARED);
 	return pool2_buffer != NULL;
 }


 /* writes <len> bytes from message <msg> to buffer <buf>. Returns -1 in case of
  * success, -2 if the message is larger than the buffer size, or the number of
  * bytes available otherwise. The send limit is automatically adjusted with the
  * amount of data written. FIXME-20060521: handle unaligned data.
  */
 int buffer_write(struct buffer *buf, const char *msg, int len)
 {
 	int max;

 	if (len == 0)
 		return -1;

 	if (len > buf->size) {
 		/* we can't write this chunk and will never be able to, because
 		 * it is larger than the buffer. This must be reported as an
 		 * error. Then we return -2 so that writers that don't care can
 		 * ignore it and go on, and others can check for this value.
 		 */
 		return -2;
 	}

 	max = buffer_realign(buf);

 	if (len > max)
 		return max;

 	memcpy(buf->r, msg, len);
 	buf->l += len;
 	buf->send_max += len;
 	buf->r += len;
 	buf->total += len;
 	if (buf->r == buf->data + buf->size)
 		buf->r = buf->data;

 	buf->flags &= ~(BF_OUT_EMPTY|BF_FULL);
 	if (buf->l >= buffer_max_len(buf))
 		buf->flags |= BF_FULL;

 	return -1;
 }

 /* Try to write string <str> into buffer <buf> after length controls. This
  * is the equivalent of buffer_write() except that to_forward and send_max
  * are updated and that max_len is respected. Returns -1 in case of success,
  * -2 if it is larger than the buffer size, or the number of bytes available
  * otherwise. The send limit is automatically adjusted with the amount of data
  * written.
  */
 int buffer_feed2(struct buffer *buf, const char *str, int len)
 {
 	int max;

 	if (len == 0)
 		return -1;

 	if (len > buffer_max_len(buf)) {
 		/* we can't write this chunk and will never be able to, because
 		 * it is larger than the buffer's current max size.
 		 */
 		return -2;
 	}

 	max = buffer_contig_space(buf);

 	if (len > max)
 		return max;

 	memcpy(buf->r, str, len);
 	buf->l += len;
 	buf->r += len;
 	buf->total += len;
 	if (buf->to_forward) {
 		unsigned long fwd = len;
 		if (buf->to_forward != BUF_INFINITE_FORWARD) {
 			if (fwd > buf->to_forward)
 				fwd = buf->to_forward;
 			buf->to_forward -= fwd;
 		}
 		buf->send_max += fwd;
 		buf->flags &= ~BF_OUT_EMPTY;
 	}

 	if (buf->r == buf->data + buf->size)
 		buf->r = buf->data;

 	buf->flags &= ~BF_FULL;
 	if (buf->l >= buffer_max_len(buf))
 		buf->flags |= BF_FULL;

 	/* notify that some data was read from the SI into the buffer */
 	buf->flags |= BF_READ_PARTIAL;
 	return -1;
 }

 /* Get one text line out of a buffer from a stream interface.
  * Return values :
  *   >0 : number of bytes read. Includes the \n if present before len or end.
  *   =0 : no '\n' before end found. <buf> is undefined.
  *   <0 : no more bytes readable + shutdown set.
  * The buffer status is not changed. The caller must call buffer_skip() to
  * update it. The '\n' is waited for as long as neither the buffer nor the
  * output are full. If either of them is full, the string may be returned
  * as is, without the '\n'.
  */
 int buffer_si_peekline(struct buffer *buf, char *str, int len)
 {
 	int ret, max;
 	char *p;

 	ret = 0;
 	max = len;
 	if (!buf->send_max) {
 		if (buf->flags & (BF_SHUTW|BF_SHUTW_NOW))
 			ret = -1;
 		goto out;
 	}

 	p = buf->w;

 	if (max > buf->send_max) {
 		max = buf->send_max;
 		str[max-1] = 0;
 	}
 	while (max) {
 		*str++ = *p;
 		ret++;
 		max--;

 		if (*p == '\n')
 			break;
 		p++;
 		if (p == buf->data + buf->size)
 			p = buf->data;
 	}
 	if (ret > 0 && ret < len && ret < buf->send_max &&
 	    *(str-1) != '\n' &&
 	    !(buf->flags & (BF_SHUTW|BF_SHUTW_NOW)))
 		ret = 0;
  out:
 	if (max)
 		*str = 0;
 	return ret;
 }

 /*
  * this function writes the string <str> at position <pos> which must be in buffer <b>,
  * and moves <end> just after the end of <str>.
  * <b>'s parameters (l, r, lr) are recomputed to be valid after the shift.
  * the shift value (positive or negative) is returned.
  * If there's no space left, the move is not done.
  * The function does not adjust ->send_max nor BF_OUT_EMPTY because it does not
  * make sense to use it on data scheduled to be sent.
  *
  */
 int buffer_replace(struct buffer *b, char *pos, char *end, const char *str)
 {
 	int delta;
 	int len;

 	len = strlen(str);
 	delta = len - (end - pos);

 	if (delta + b->r >= b->data + b->size)
 		return 0;  /* no space left */

 	if (delta + b->r > b->w && b->w >= b->r && b->l)
 		return 0;  /* no space left before wrapping data */

 	/* first, protect the end of the buffer */
 	memmove(end + delta, end, b->r - end);

 	/* now, copy str over pos */
 	memcpy(pos, str,len);

 	/* we only move data after the displaced zone */
 	if (b->r  > pos) b->r  += delta;
 	if (b->lr > pos) b->lr += delta;
 	b->l += delta;

 	b->flags &= ~BF_FULL;
 	if (b->l == 0)
 		b->r = b->w = b->lr = b->data;
 	if (b->l >= buffer_max_len(b))
 		b->flags |= BF_FULL;

 	return delta;
 }

 /*
  * same except that the string length is given, which allows str to be NULL if
  * len is 0. The send limit is *not* adjusted.
  */
 int buffer_replace2(struct buffer *b, char *pos, char *end, const char *str, int len)
 {
 	int delta;

 	delta = len - (end - pos);

 	if (delta + b->r >= b->data + b->size)
 		return 0;  /* no space left */

 	if (delta + b->r > b->w && b->w >= b->r && b->l)
 		return 0;  /* no space left before wrapping data */

 	/* first, protect the end of the buffer */
 	memmove(end + delta, end, b->r - end);

 	/* now, copy str over pos */
 	if (len)
 		memcpy(pos, str, len);

 	/* we only move data after the displaced zone */
 	if (b->r  > pos) b->r  += delta;
 	if (b->lr > pos) b->lr += delta;
 	b->l += delta;

 	b->flags &= ~BF_FULL;
 	if (b->l == 0)
 		b->r = b->w = b->lr = b->data;
 	if (b->l >= buffer_max_len(b))
 		b->flags |= BF_FULL;

 	return delta;
 }


 /*
  * Inserts <str> followed by "\r\n" at position <pos> in buffer <b>. The <len>
  * argument informs about the length of string <str> so that we don't have to
  * measure it. It does not include the "\r\n". If <str> is NULL, then the buffer
  * is only opened for len+2 bytes but nothing is copied in. It may be useful in
  * some circumstances. The send limit is *not* adjusted.
  *
  * The number of bytes added is returned on success. 0 is returned on failure.
  */
 int buffer_insert_line2(struct buffer *b, char *pos, const char *str, int len)
 {
 	int delta;

 	delta = len + 2;

 	if (delta + b->r >= b->data + b->size)
 		return 0;  /* no space left */

 	/* first, protect the end of the buffer */
 	memmove(pos + delta, pos, b->r - pos);

 	/* now, copy str over pos */
 	if (len && str) {
 		memcpy(pos, str, len);
 		pos[len] = '\r';
 		pos[len + 1] = '\n';
 	}

 	/* we only move data after the displaced zone */
 	if (b->r  > pos) b->r  += delta;
 	if (b->lr > pos) b->lr += delta;
 	b->l += delta;

 	b->flags &= ~BF_FULL;
 	if (b->l >= buffer_max_len(b))
 		b->flags |= BF_FULL;

 	return delta;
 }


 /* Realigns a possibly non-contiguous buffer by bouncing bytes from source to
  * destination. It does not use any intermediate buffer and does the move in
  * place, though it will be slower than a simple memmove() on contiguous data,
  * so it's desirable to use it only on non-contiguous buffers. No pointers are
  * changed, the caller is responsible for that.
  */
 void buffer_bounce_realign(struct buffer *buf)
 {
 	int advance, to_move;
 	char *from, *to;

 	advance = buf->data + buf->size - buf->w;
 	if (!advance)
 		return;

 	from = buf->w;
 	to_move = buf->l;
 	while (to_move) {
 		char last, save;

 		last = *from;
 		to = from + advance;
 		if (to >= buf->data + buf->size)
 			to -= buf->size;

 		while (1) {
 			save = *to;
 			*to  = last;
 			last = save;
 			to_move--;
 			if (!to_move)
 				break;

 			/* check if we went back home after rotating a number of bytes */
 			if (to == from)
 				break;

 			/* if we ended up in the empty area, let's walk to next place. The
 			 * empty area is either between buf->r and from or before from or
 			 * after buf->r.
 			 */
 			if (from > buf->r) {
 				if (to >= buf->r && to < from)
 					break;
 			} else if (from < buf->r) {
 				if (to < from || to >= buf->r)
 					break;
 			}

 			/* we have overwritten a byte of the original set, let's move it */
 			to += advance;
 			if (to >= buf->data + buf->size)
 				to -= buf->size;
 		}

 		from++;
 		if (from >= buf->data + buf->size)
 			from -= buf->size;
 	}
 }


 /*
  * Does an snprintf() at the end of chunk <chk>, respecting the limit of
  * at most chk->size chars. If the chk->len is over, nothing is added. Returns
  * the new chunk size.
  */
 int chunk_printf(struct chunk *chk, const char *fmt, ...)
 {
 	va_list argp;
 	int ret;

 	if (!chk->str || !chk->size)
 		return 0;

 	va_start(argp, fmt);
 	ret = vsnprintf(chk->str + chk->len, chk->size - chk->len, fmt, argp);
 	if (ret >= chk->size - chk->len)
 		/* do not copy anything in case of truncation */
 		chk->str[chk->len] = 0;
 	else
 		chk->len += ret;
 	va_end(argp);
 	return chk->len;
 }

 /*
  * Encode chunk <src> into chunk <dst>, respecting the limit of at most
  * chk->size chars. Replace non-printable or special chracters with "&#%d;".
  * If the chk->len is over, nothing is added. Returns the new chunk size.
  */
 int chunk_htmlencode(struct chunk *dst, struct chunk *src) {

 	int i, l;
 	int olen, free;
 	char c;

 	olen = dst->len;

 	for (i = 0; i < src->len; i++) {
 		free = dst->size - dst->len;

 		if (!free) {
 			dst->len = olen;
 			return dst->len;
 		}

 		c = src->str[i];

 		if (!isascii(c) || !isprint(c) || c == '&' || c == '"' || c == '\'' || c == '<' || c == '>') {
 			l = snprintf(dst->str + dst->len, free, "&#%u;", (unsigned char)c);

 			if (free < l) {
 				dst->len = olen;
 				return dst->len;
 			}

 			dst->len += l;
 		} else {
 			dst->str[dst->len] = c;
 			dst->len++;
 		}
 	}

 	return dst->len;
 }

 /*
  * Encode chunk <src> into chunk <dst>, respecting the limit of at most
  * chk->size chars. Replace non-printable or char passed in qc with "<%02X>".
  * If the chk->len is over, nothing is added. Returns the new chunk size.
  */
 int chunk_asciiencode(struct chunk *dst, struct chunk *src, char qc) {
 	int i, l;
 	int olen, free;
 	char c;

 	olen = dst->len;

 	for (i = 0; i < src->len; i++) {
 		free = dst->size - dst->len;

 		if (!free) {
 			dst->len = olen;
 			return dst->len;
 		}

 		c = src->str[i];

 		if (!isascii(c) || !isprint(c) || c == '<' || c == '>' || c == qc) {
 			l = snprintf(dst->str + dst->len, free, "<%02X>", (unsigned char)c);

 			if (free < l) {
 				dst->len = olen;
 				return dst->len;
 			}

 			dst->len += l;
 		} else {
 			dst->str[dst->len] = c;
 			dst->len++;
 		}
 	}

 	return dst->len;
 }

 /*
  * Dumps part or all of a buffer.
  */
 void buffer_dump(FILE *o, struct buffer *b, int from, int to)
 {
 	fprintf(o, "Dumping buffer %p\n", b);
 	fprintf(o, "  data=%p l=%d r=%p w=%p lr=%p\n",
 		b->data, b->l, b->r, b->w, b->lr);

 	if (!to || to > b->l)
 		to = b->l;

 	fprintf(o, "Dumping contents from byte %d to byte %d\n", from, to);
 	for (; from < to; from++) {
 		if ((from & 15) == 0)
 			fprintf(o, "  %04x: ", from);
 		fprintf(o, "%02x ", b->data[from]);
 		if ((from & 15) == 7)
 			fprintf(o, "- ");
 		else if (((from & 15) == 15) && (from != to-1))
 			fprintf(o, "\n");
 	}
 	fprintf(o, "\n--\n");
 }


 /*
  * Local variables:
  *  c-indent-level: 8
  *  c-basic-offset: 8
  * End:
  */
	/*
	* Buffer management functions.
	*
	* Copyright 2000-2010 Willy Tarreau <w@1wt.eu>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*
	*/

	#include <ctype.h>
	#include <stdarg.h>
	#include <stdio.h>
	#include <string.h>

	#include <common/config.h>
	#include <common/memory.h>
	#include <proto/buffers.h>
	#include <types/global.h>

	struct pool_head *pool2_buffer;


	/* perform minimal intializations, report 0 in case of error, 1 if OK. */
	int init_buffer()
	{
	pool2_buffer = create_pool("buffer", sizeof(struct buffer) + global.tune.bufsize, MEM_F_SHARED);
	return pool2_buffer != NULL;
	}


	/* writes <len> bytes from message <msg> to buffer <buf>. Returns -1 in case of
	* success, -2 if the message is larger than the buffer size, or the number of
	* bytes available otherwise. The send limit is automatically adjusted with the
	* amount of data written. FIXME-20060521: handle unaligned data.
	*/
	int buffer_write(struct buffer buf, const char msg, int len)
	{
	int max;

	if (len == 0)
	return -1;

	if (len > buf->size) {
	/* we can't write this chunk and will never be able to, because
	* it is larger than the buffer. This must be reported as an
	* error. Then we return -2 so that writers that don't care can
	* ignore it and go on, and others can check for this value.
	*/
	return -2;
	}

	max = buffer_realign(buf);

	if (len > max)
	return max;

	memcpy(buf->r, msg, len);
	buf->l += len;
	buf->send_max += len;
	buf->r += len;
	buf->total += len;
	if (buf->r == buf->data + buf->size)
	buf->r = buf->data;

	buf->flags &= ~(BF_OUT_EMPTY\|BF_FULL);
	if (buf->l >= buffer_max_len(buf))
	buf->flags \|= BF_FULL;

	return -1;
	}

	/* Try to write string <str> into buffer <buf> after length controls. This
	* is the equivalent of buffer_write() except that to_forward and send_max
	* are updated and that max_len is respected. Returns -1 in case of success,
	* -2 if it is larger than the buffer size, or the number of bytes available
	* otherwise. The send limit is automatically adjusted with the amount of data
	* written.
	*/
	int buffer_feed2(struct buffer buf, const char str, int len)
	{
	int max;

	if (len == 0)
	return -1;

	if (len > buffer_max_len(buf)) {
	/* we can't write this chunk and will never be able to, because
	* it is larger than the buffer's current max size.
	*/
	return -2;
	}

	max = buffer_contig_space(buf);

	if (len > max)
	return max;

	memcpy(buf->r, str, len);
	buf->l += len;
	buf->r += len;
	buf->total += len;
	if (buf->to_forward) {
	unsigned long fwd = len;
	if (buf->to_forward != BUF_INFINITE_FORWARD) {
	if (fwd > buf->to_forward)
	fwd = buf->to_forward;
	buf->to_forward -= fwd;
	}
	buf->send_max += fwd;
	buf->flags &= ~BF_OUT_EMPTY;
	}

	if (buf->r == buf->data + buf->size)
	buf->r = buf->data;

	buf->flags &= ~BF_FULL;
	if (buf->l >= buffer_max_len(buf))
	buf->flags \|= BF_FULL;

	/* notify that some data was read from the SI into the buffer */
	buf->flags \|= BF_READ_PARTIAL;
	return -1;
	}

	/* Get one text line out of a buffer from a stream interface.
	* Return values :
	* >0 : number of bytes read. Includes the \n if present before len or end.
	* =0 : no '\n' before end found. <buf> is undefined.
	* <0 : no more bytes readable + shutdown set.
	* The buffer status is not changed. The caller must call buffer_skip() to
	* update it. The '\n' is waited for as long as neither the buffer nor the
	* output are full. If either of them is full, the string may be returned
	* as is, without the '\n'.
	*/
	int buffer_si_peekline(struct buffer buf, char str, int len)
	{
	int ret, max;
	char *p;

	ret = 0;
	max = len;
	if (!buf->send_max) {
	if (buf->flags & (BF_SHUTW\|BF_SHUTW_NOW))
	ret = -1;
	goto out;
	}

	p = buf->w;

	if (max > buf->send_max) {
	max = buf->send_max;
	str[max-1] = 0;
	}
	while (max) {
	str++ = p;
	ret++;
	max--;

	if (*p == '\n')
	break;
	p++;
	if (p == buf->data + buf->size)
	p = buf->data;
	}
	if (ret > 0 && ret < len && ret < buf->send_max &&
	*(str-1) != '\n' &&
	!(buf->flags & (BF_SHUTW\|BF_SHUTW_NOW)))
	ret = 0;
	out:
	if (max)
	*str = 0;
	return ret;
	}

	/*
	* this function writes the string <str> at position <pos> which must be in buffer <b>,
	* and moves <end> just after the end of <str>.
	* <b>'s parameters (l, r, lr) are recomputed to be valid after the shift.
	* the shift value (positive or negative) is returned.
	* If there's no space left, the move is not done.
	* The function does not adjust ->send_max nor BF_OUT_EMPTY because it does not
	* make sense to use it on data scheduled to be sent.
	*
	*/
	int buffer_replace(struct buffer b, char pos, char end, const char str)
	{
	int delta;
	int len;

	len = strlen(str);
	delta = len - (end - pos);

	if (delta + b->r >= b->data + b->size)
	return 0; /* no space left */

	if (delta + b->r > b->w && b->w >= b->r && b->l)
	return 0; /* no space left before wrapping data */

	/* first, protect the end of the buffer */
	memmove(end + delta, end, b->r - end);

	/* now, copy str over pos */
	memcpy(pos, str,len);

	/* we only move data after the displaced zone */
	if (b->r > pos) b->r += delta;
	if (b->lr > pos) b->lr += delta;
	b->l += delta;

	b->flags &= ~BF_FULL;
	if (b->l == 0)
	b->r = b->w = b->lr = b->data;
	if (b->l >= buffer_max_len(b))
	b->flags \|= BF_FULL;

	return delta;
	}

	/*
	* same except that the string length is given, which allows str to be NULL if
	* len is 0. The send limit is not adjusted.
	*/
	int buffer_replace2(struct buffer b, char pos, char end, const char str, int len)
	{
	int delta;

	delta = len - (end - pos);

	if (delta + b->r >= b->data + b->size)
	return 0; /* no space left */

	if (delta + b->r > b->w && b->w >= b->r && b->l)
	return 0; /* no space left before wrapping data */

	/* first, protect the end of the buffer */
	memmove(end + delta, end, b->r - end);

	/* now, copy str over pos */
	if (len)
	memcpy(pos, str, len);

	/* we only move data after the displaced zone */
	if (b->r > pos) b->r += delta;
	if (b->lr > pos) b->lr += delta;
	b->l += delta;

	b->flags &= ~BF_FULL;
	if (b->l == 0)
	b->r = b->w = b->lr = b->data;
	if (b->l >= buffer_max_len(b))
	b->flags \|= BF_FULL;

	return delta;
	}


	/*
	* Inserts <str> followed by "\r\n" at position <pos> in buffer <b>. The <len>
	* argument informs about the length of string <str> so that we don't have to
	* measure it. It does not include the "\r\n". If <str> is NULL, then the buffer
	* is only opened for len+2 bytes but nothing is copied in. It may be useful in
	* some circumstances. The send limit is not adjusted.
	*
	* The number of bytes added is returned on success. 0 is returned on failure.
	*/
	int buffer_insert_line2(struct buffer b, char pos, const char *str, int len)
	{
	int delta;

	delta = len + 2;

	if (delta + b->r >= b->data + b->size)
	return 0; /* no space left */

	/* first, protect the end of the buffer */
	memmove(pos + delta, pos, b->r - pos);

	/* now, copy str over pos */
	if (len && str) {
	memcpy(pos, str, len);
	pos[len] = '\r';
	pos[len + 1] = '\n';
	}

	/* we only move data after the displaced zone */
	if (b->r > pos) b->r += delta;
	if (b->lr > pos) b->lr += delta;
	b->l += delta;

	b->flags &= ~BF_FULL;
	if (b->l >= buffer_max_len(b))
	b->flags \|= BF_FULL;

	return delta;
	}


	/* Realigns a possibly non-contiguous buffer by bouncing bytes from source to
	* destination. It does not use any intermediate buffer and does the move in
	* place, though it will be slower than a simple memmove() on contiguous data,
	* so it's desirable to use it only on non-contiguous buffers. No pointers are
	* changed, the caller is responsible for that.
	*/
	void buffer_bounce_realign(struct buffer *buf)
	{
	int advance, to_move;
	char from, to;

	advance = buf->data + buf->size - buf->w;
	if (!advance)
	return;

	from = buf->w;
	to_move = buf->l;
	while (to_move) {
	char last, save;

	last = *from;
	to = from + advance;
	if (to >= buf->data + buf->size)
	to -= buf->size;

	while (1) {
	save = *to;
	*to = last;
	last = save;
	to_move--;
	if (!to_move)
	break;

	/* check if we went back home after rotating a number of bytes */
	if (to == from)
	break;

	/* if we ended up in the empty area, let's walk to next place. The
	* empty area is either between buf->r and from or before from or
	* after buf->r.
	*/
	if (from > buf->r) {
	if (to >= buf->r && to < from)
	break;
	} else if (from < buf->r) {
	if (to < from \|\| to >= buf->r)
	break;
	}

	/* we have overwritten a byte of the original set, let's move it */
	to += advance;
	if (to >= buf->data + buf->size)
	to -= buf->size;
	}

	from++;
	if (from >= buf->data + buf->size)
	from -= buf->size;
	}
	}


	/*
	* Does an snprintf() at the end of chunk <chk>, respecting the limit of
	* at most chk->size chars. If the chk->len is over, nothing is added. Returns
	* the new chunk size.
	*/
	int chunk_printf(struct chunk chk, const char fmt, ...)
	{
	va_list argp;
	int ret;

	if (!chk->str \|\| !chk->size)
	return 0;

	va_start(argp, fmt);
	ret = vsnprintf(chk->str + chk->len, chk->size - chk->len, fmt, argp);
	if (ret >= chk->size - chk->len)
	/* do not copy anything in case of truncation */
	chk->str[chk->len] = 0;
	else
	chk->len += ret;
	va_end(argp);
	return chk->len;
	}

	/*
	* Encode chunk <src> into chunk <dst>, respecting the limit of at most
	* chk->size chars. Replace non-printable or special chracters with "&#%d;".
	* If the chk->len is over, nothing is added. Returns the new chunk size.
	*/
	int chunk_htmlencode(struct chunk dst, struct chunk src) {

	int i, l;
	int olen, free;
	char c;

	olen = dst->len;

	for (i = 0; i < src->len; i++) {
	free = dst->size - dst->len;

	if (!free) {
	dst->len = olen;
	return dst->len;
	}

	c = src->str[i];

	if (!isascii(c) \|\| !isprint(c) \|\| c == '&' \|\| c == '"' \|\| c == '\'' \|\| c == '<' \|\| c == '>') {
	l = snprintf(dst->str + dst->len, free, "&#%u;", (unsigned char)c);

	if (free < l) {
	dst->len = olen;
	return dst->len;
	}

	dst->len += l;
	} else {
	dst->str[dst->len] = c;
	dst->len++;
	}
	}

	return dst->len;
	}

	/*
	* Encode chunk <src> into chunk <dst>, respecting the limit of at most
	* chk->size chars. Replace non-printable or char passed in qc with "<%02X>".
	* If the chk->len is over, nothing is added. Returns the new chunk size.
	*/
	int chunk_asciiencode(struct chunk dst, struct chunk src, char qc) {
	int i, l;
	int olen, free;
	char c;

	olen = dst->len;

	for (i = 0; i < src->len; i++) {
	free = dst->size - dst->len;

	if (!free) {
	dst->len = olen;
	return dst->len;
	}

	c = src->str[i];

	if (!isascii(c) \|\| !isprint(c) \|\| c == '<' \|\| c == '>' \|\| c == qc) {
	l = snprintf(dst->str + dst->len, free, "<%02X>", (unsigned char)c);

	if (free < l) {
	dst->len = olen;
	return dst->len;
	}

	dst->len += l;
	} else {
	dst->str[dst->len] = c;
	dst->len++;
	}
	}

	return dst->len;
	}

	/*
	* Dumps part or all of a buffer.
	*/
	void buffer_dump(FILE o, struct buffer b, int from, int to)
	{
	fprintf(o, "Dumping buffer %p\n", b);
	fprintf(o, " data=%p l=%d r=%p w=%p lr=%p\n",
	b->data, b->l, b->r, b->w, b->lr);

	if (!to \|\| to > b->l)
	to = b->l;

	fprintf(o, "Dumping contents from byte %d to byte %d\n", from, to);
	for (; from < to; from++) {
	if ((from & 15) == 0)
	fprintf(o, " %04x: ", from);
	fprintf(o, "%02x ", b->data[from]);
	if ((from & 15) == 7)
	fprintf(o, "- ");
	else if (((from & 15) == 15) && (from != to-1))
	fprintf(o, "\n");
	}
	fprintf(o, "\n--\n");
	}


	/*
	* Local variables:
	* c-indent-level: 8
	* c-basic-offset: 8
	* End:
	*/