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 channel) + global.tune.bufsize, MEM_F_SHARED);
 	return pool2_buffer != NULL;
 }

 /* Schedule up to <bytes> more bytes to be forwarded by the buffer without notifying
  * the task. Any pending data in the buffer is scheduled to be sent as well,
  * in the limit of the number of bytes to forward. This must be the only method
  * to use to schedule bytes to be sent. If the requested number is too large, it
  * is automatically adjusted. The number of bytes taken into account is returned.
  * Directly touching ->to_forward will cause lockups when ->o goes down to
  * zero if nobody is ready to push the remaining data.
  */
 unsigned long long buffer_forward(struct channel *buf, unsigned long long bytes)
 {
 	unsigned int new_forward;
 	unsigned int forwarded;
 	unsigned int bytes32;

 	bytes32 = bytes;

 	/* hint: avoid comparisons on long long for the fast case, since if the
 	 * length does not fit in an unsigned it, it will never be forwarded at
 	 * once anyway.
 	 */
 	if (bytes <= ~0U) {
 		if (bytes32 <= buf->i) {
 			/* OK this amount of bytes might be forwarded at once */
 			if (!bytes32)
 				return 0;
 			b_adv(buf, bytes32);
 			return bytes;
 		}
 	}

 	forwarded = buf->i;
 	b_adv(buf, buf->i);

 	/* Note: the case below is the only case where we may return
 	 * a byte count that does not fit into a 32-bit number.
 	 */
 	if (likely(buf->to_forward == BUF_INFINITE_FORWARD))
 		return bytes;

 	if (likely(bytes == BUF_INFINITE_FORWARD)) {
 		buf->to_forward = bytes;
 		return bytes;
 	}

 	new_forward = buf->to_forward + bytes - forwarded;
 	bytes = forwarded; /* at least those bytes were scheduled */

 	if (new_forward <= buf->to_forward) {
 		/* integer overflow detected, let's assume no more than 2G at once */
 		new_forward = MID_RANGE(new_forward);
 	}

 	if (new_forward > buf->to_forward) {
 		bytes += new_forward - buf->to_forward;
 		buf->to_forward = new_forward;
 	}
 	return bytes;
 }

 /* 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.
  * Note: this function appends data to the buffer's output and possibly overwrites
  * any pending input data which are assumed not to exist.
  */
 int bo_inject(struct channel *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->p, msg, len);
 	buf->o += len;
 	buf->p = b_ptr(buf, len);
 	buf->total += len;

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

 	return -1;
 }

 /* Tries to copy character <c> into buffer <buf> after length controls. The
  * ->o and to_forward pointers are updated. If the buffer's input is
  * closed, -2 is returned. If there is not enough room left in the buffer, -1
  * is returned. Otherwise the number of bytes copied is returned (1). Buffer
  * flags FULL, EMPTY and READ_PARTIAL are updated if some data can be
  * transferred.
  */
 int bi_putchr(struct channel *buf, char c)
 {
 	if (unlikely(buffer_input_closed(buf)))
 		return -2;

 	if (buf->flags & BF_FULL)
 		return -1;

 	*bi_end(buf) = c;

 	buf->i++;
 	if (bi_full(buf))
 		buf->flags |= BF_FULL;
 	buf->flags |= BF_READ_PARTIAL;

 	if (buf->to_forward >= 1) {
 		if (buf->to_forward != BUF_INFINITE_FORWARD)
 			buf->to_forward--;
 		b_adv(buf, 1);
 	}

 	buf->total++;
 	return 1;
 }

 /* Tries to copy block <blk> at once into buffer <buf> after length controls.
  * The ->o and to_forward pointers are updated. If the buffer's input is
  * closed, -2 is returned. If the block is too large for this buffer, -3 is
  * returned. If there is not enough room left in the buffer, -1 is returned.
  * Otherwise the number of bytes copied is returned (0 being a valid number).
  * Buffer flags FULL, EMPTY and READ_PARTIAL are updated if some data can be
  * transferred.
  */
 int bi_putblk(struct channel *buf, const char *blk, int len)
 {
 	int max;

 	if (unlikely(buffer_input_closed(buf)))
 		return -2;

 	max = buffer_max_len(buf);
 	if (unlikely(len > max - buffer_len(buf))) {
 		/* we can't write this chunk right now because the buffer is
 		 * almost full or because the block is too large. Return the
 		 * available space or -2 if impossible.
 		 */
 		if (len > max)
 			return -3;

 		return -1;
 	}

 	if (unlikely(len == 0))
 		return 0;

 	/* OK so the data fits in the buffer in one or two blocks */
 	max = buffer_contig_space_with_res(buf, buf->size - max);
 	memcpy(bi_end(buf), blk, MIN(len, max));
 	if (len > max)
 		memcpy(buf->data, blk + max, len - max);

 	buf->i += 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;
 		}
 		b_adv(buf, fwd);
 	}

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

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

 /* Gets 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. <str> is left undefined.
  *   <0 : no more bytes readable because output is shut.
  * The buffer status is not changed. The caller must call bo_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 bo_getline(struct channel *buf, char *str, int len)
 {
 	int ret, max;
 	char *p;

 	ret = 0;
 	max = len;

 	/* closed or empty + imminent close = -1; empty = 0 */
 	if (unlikely(buf->flags & (BF_OUT_EMPTY|BF_SHUTW))) {
 		if (buf->flags & (BF_SHUTW|BF_SHUTW_NOW))
 			ret = -1;
 		goto out;
 	}

 	p = bo_ptr(buf);

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

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

 /* Gets one full block of data at once from a buffer, optionally from a
  * specific offset. Return values :
  *   >0 : number of bytes read, equal to requested size.
  *   =0 : not enough data available. <blk> is left undefined.
  *   <0 : no more bytes readable because output is shut.
  * The buffer status is not changed. The caller must call bo_skip() to
  * update it.
  */
 int bo_getblk(struct channel *buf, char *blk, int len, int offset)
 {
 	int firstblock;

 	if (buf->flags & BF_SHUTW)
 		return -1;

 	if (len + offset > buf->o) {
 		if (buf->flags & (BF_SHUTW|BF_SHUTW_NOW))
 			return -1;
 		return 0;
 	}

 	firstblock = buf->data + buf->size - bo_ptr(buf);
 	if (firstblock > offset) {
 		if (firstblock >= len + offset) {
 			memcpy(blk, bo_ptr(buf) + offset, len);
 			return len;
 		}

 		memcpy(blk, bo_ptr(buf) + offset, firstblock - offset);
 		memcpy(blk + firstblock - offset, buf->data, len - firstblock + offset);
 		return len;
 	}

 	memcpy(blk, buf->data + offset - firstblock, len);
 	return len;
 }

 /* 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> and <r> are updated 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 ->o nor BF_OUT_EMPTY because it
  * does not make sense to use it on data scheduled to be sent. For the same
  * reason, it does not make sense to call this function on unparsed data, so
  * <orig> is not updated. The string length is taken from parameter <len>. If
  * <len> is null, the <str> pointer is allowed to be null.
  */
 int buffer_replace2(struct channel *b, char *pos, char *end, const char *str, int len)
 {
 	int delta;

 	delta = len - (end - pos);

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

 	if (buffer_not_empty(b) &&
 	    bi_end(b) + delta > bo_ptr(b) &&
 	    bo_ptr(b) >= bi_end(b))
 		return 0;  /* no space left before wrapping data */

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

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

 	b->i += delta;

 	b->flags &= ~BF_FULL;
 	if (buffer_len(b) == 0)
 		b->p = b->data;
 	if (bi_full(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. Same comments as above
  * for the valid use cases.
  *
  * The number of bytes added is returned on success. 0 is returned on failure.
  */
 int buffer_insert_line2(struct channel *b, char *pos, const char *str, int len)
 {
 	int delta;

 	delta = len + 2;

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

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

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

 	b->i += delta;

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

 	return delta;
 }


 /* This function realigns input data in a possibly wrapping buffer so that it
  * becomes contiguous and starts at the beginning of the buffer area. The
  * function may only be used when the buffer's output is empty.
  */
 void buffer_slow_realign(struct channel *buf)
 {
 	/* two possible cases :
 	 *   - the buffer is in one contiguous block, we move it in-place
 	 *   - the buffer is in two blocks, we move it via the swap_buffer
 	 */
 	if (buf->i) {
 		int block1 = buf->i;
 		int block2 = 0;
 		if (buf->p + buf->i > buf->data + buf->size) {
 			/* non-contiguous block */
 			block1 = buf->data + buf->size - buf->p;
 			block2 = buf->p + buf->i - (buf->data + buf->size);
 		}
 		if (block2)
 			memcpy(swap_buffer, buf->data, block2);
 		memmove(buf->data, buf->p, block1);
 		if (block2)
 			memcpy(buf->data + block1, swap_buffer, block2);
 	}

 	buf->p = buf->data;
 }

 /* 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 channel *buf)
 {
 	int advance, to_move;
 	char *from, *to;

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

 	to_move = buffer_len(buf);
 	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 > bi_end(buf)) {
 				if (to >= bi_end(buf) && to < from)
 					break;
 			} else if (from < bi_end(buf)) {
 				if (to < from || to >= bi_end(buf))
 					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((unsigned char)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((unsigned char)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 channel *b, int from, int to)
 {
 	fprintf(o, "Dumping buffer %p\n", b);
 	fprintf(o, "  data=%p o=%d i=%d p=%p\n",
 		b->data, b->o, b->i, b->p);

 	if (!to || to > buffer_len(b))
 		to = buffer_len(b);

 	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 channel) + global.tune.bufsize, MEM_F_SHARED);
	return pool2_buffer != NULL;
	}

	/* Schedule up to <bytes> more bytes to be forwarded by the buffer without notifying
	* the task. Any pending data in the buffer is scheduled to be sent as well,
	* in the limit of the number of bytes to forward. This must be the only method
	* to use to schedule bytes to be sent. If the requested number is too large, it
	* is automatically adjusted. The number of bytes taken into account is returned.
	* Directly touching ->to_forward will cause lockups when ->o goes down to
	* zero if nobody is ready to push the remaining data.
	*/
	unsigned long long buffer_forward(struct channel *buf, unsigned long long bytes)
	{
	unsigned int new_forward;
	unsigned int forwarded;
	unsigned int bytes32;

	bytes32 = bytes;

	/* hint: avoid comparisons on long long for the fast case, since if the
	* length does not fit in an unsigned it, it will never be forwarded at
	* once anyway.
	*/
	if (bytes <= ~0U) {
	if (bytes32 <= buf->i) {
	/* OK this amount of bytes might be forwarded at once */
	if (!bytes32)
	return 0;
	b_adv(buf, bytes32);
	return bytes;
	}
	}

	forwarded = buf->i;
	b_adv(buf, buf->i);

	/* Note: the case below is the only case where we may return
	* a byte count that does not fit into a 32-bit number.
	*/
	if (likely(buf->to_forward == BUF_INFINITE_FORWARD))
	return bytes;

	if (likely(bytes == BUF_INFINITE_FORWARD)) {
	buf->to_forward = bytes;
	return bytes;
	}

	new_forward = buf->to_forward + bytes - forwarded;
	bytes = forwarded; /* at least those bytes were scheduled */

	if (new_forward <= buf->to_forward) {
	/* integer overflow detected, let's assume no more than 2G at once */
	new_forward = MID_RANGE(new_forward);
	}

	if (new_forward > buf->to_forward) {
	bytes += new_forward - buf->to_forward;
	buf->to_forward = new_forward;
	}
	return bytes;
	}

	/* 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.
	* Note: this function appends data to the buffer's output and possibly overwrites
	* any pending input data which are assumed not to exist.
	*/
	int bo_inject(struct channel 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->p, msg, len);
	buf->o += len;
	buf->p = b_ptr(buf, len);
	buf->total += len;

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

	return -1;
	}

	/* Tries to copy character <c> into buffer <buf> after length controls. The
	* ->o and to_forward pointers are updated. If the buffer's input is
	* closed, -2 is returned. If there is not enough room left in the buffer, -1
	* is returned. Otherwise the number of bytes copied is returned (1). Buffer
	* flags FULL, EMPTY and READ_PARTIAL are updated if some data can be
	* transferred.
	*/
	int bi_putchr(struct channel *buf, char c)
	{
	if (unlikely(buffer_input_closed(buf)))
	return -2;

	if (buf->flags & BF_FULL)
	return -1;

	*bi_end(buf) = c;

	buf->i++;
	if (bi_full(buf))
	buf->flags \|= BF_FULL;
	buf->flags \|= BF_READ_PARTIAL;

	if (buf->to_forward >= 1) {
	if (buf->to_forward != BUF_INFINITE_FORWARD)
	buf->to_forward--;
	b_adv(buf, 1);
	}

	buf->total++;
	return 1;
	}

	/* Tries to copy block <blk> at once into buffer <buf> after length controls.
	* The ->o and to_forward pointers are updated. If the buffer's input is
	* closed, -2 is returned. If the block is too large for this buffer, -3 is
	* returned. If there is not enough room left in the buffer, -1 is returned.
	* Otherwise the number of bytes copied is returned (0 being a valid number).
	* Buffer flags FULL, EMPTY and READ_PARTIAL are updated if some data can be
	* transferred.
	*/
	int bi_putblk(struct channel buf, const char blk, int len)
	{
	int max;

	if (unlikely(buffer_input_closed(buf)))
	return -2;

	max = buffer_max_len(buf);
	if (unlikely(len > max - buffer_len(buf))) {
	/* we can't write this chunk right now because the buffer is
	* almost full or because the block is too large. Return the
	* available space or -2 if impossible.
	*/
	if (len > max)
	return -3;

	return -1;
	}

	if (unlikely(len == 0))
	return 0;

	/* OK so the data fits in the buffer in one or two blocks */
	max = buffer_contig_space_with_res(buf, buf->size - max);
	memcpy(bi_end(buf), blk, MIN(len, max));
	if (len > max)
	memcpy(buf->data, blk + max, len - max);

	buf->i += 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;
	}
	b_adv(buf, fwd);
	}

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

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

	/* Gets 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. <str> is left undefined.
	* <0 : no more bytes readable because output is shut.
	* The buffer status is not changed. The caller must call bo_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 bo_getline(struct channel buf, char str, int len)
	{
	int ret, max;
	char *p;

	ret = 0;
	max = len;

	/* closed or empty + imminent close = -1; empty = 0 */
	if (unlikely(buf->flags & (BF_OUT_EMPTY\|BF_SHUTW))) {
	if (buf->flags & (BF_SHUTW\|BF_SHUTW_NOW))
	ret = -1;
	goto out;
	}

	p = bo_ptr(buf);

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

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

	/* Gets one full block of data at once from a buffer, optionally from a
	* specific offset. Return values :
	* >0 : number of bytes read, equal to requested size.
	* =0 : not enough data available. <blk> is left undefined.
	* <0 : no more bytes readable because output is shut.
	* The buffer status is not changed. The caller must call bo_skip() to
	* update it.
	*/
	int bo_getblk(struct channel buf, char blk, int len, int offset)
	{
	int firstblock;

	if (buf->flags & BF_SHUTW)
	return -1;

	if (len + offset > buf->o) {
	if (buf->flags & (BF_SHUTW\|BF_SHUTW_NOW))
	return -1;
	return 0;
	}

	firstblock = buf->data + buf->size - bo_ptr(buf);
	if (firstblock > offset) {
	if (firstblock >= len + offset) {
	memcpy(blk, bo_ptr(buf) + offset, len);
	return len;
	}

	memcpy(blk, bo_ptr(buf) + offset, firstblock - offset);
	memcpy(blk + firstblock - offset, buf->data, len - firstblock + offset);
	return len;
	}

	memcpy(blk, buf->data + offset - firstblock, len);
	return len;
	}

	/* 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> and <r> are updated 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 ->o nor BF_OUT_EMPTY because it
	* does not make sense to use it on data scheduled to be sent. For the same
	* reason, it does not make sense to call this function on unparsed data, so
	* <orig> is not updated. The string length is taken from parameter <len>. If
	* <len> is null, the <str> pointer is allowed to be null.
	*/
	int buffer_replace2(struct channel b, char pos, char end, const char str, int len)
	{
	int delta;

	delta = len - (end - pos);

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

	if (buffer_not_empty(b) &&
	bi_end(b) + delta > bo_ptr(b) &&
	bo_ptr(b) >= bi_end(b))
	return 0; /* no space left before wrapping data */

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

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

	b->i += delta;

	b->flags &= ~BF_FULL;
	if (buffer_len(b) == 0)
	b->p = b->data;
	if (bi_full(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. Same comments as above
	* for the valid use cases.
	*
	* The number of bytes added is returned on success. 0 is returned on failure.
	*/
	int buffer_insert_line2(struct channel b, char pos, const char *str, int len)
	{
	int delta;

	delta = len + 2;

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

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

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

	b->i += delta;

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

	return delta;
	}


	/* This function realigns input data in a possibly wrapping buffer so that it
	* becomes contiguous and starts at the beginning of the buffer area. The
	* function may only be used when the buffer's output is empty.
	*/
	void buffer_slow_realign(struct channel *buf)
	{
	/* two possible cases :
	* - the buffer is in one contiguous block, we move it in-place
	* - the buffer is in two blocks, we move it via the swap_buffer
	*/
	if (buf->i) {
	int block1 = buf->i;
	int block2 = 0;
	if (buf->p + buf->i > buf->data + buf->size) {
	/* non-contiguous block */
	block1 = buf->data + buf->size - buf->p;
	block2 = buf->p + buf->i - (buf->data + buf->size);
	}
	if (block2)
	memcpy(swap_buffer, buf->data, block2);
	memmove(buf->data, buf->p, block1);
	if (block2)
	memcpy(buf->data + block1, swap_buffer, block2);
	}

	buf->p = buf->data;
	}

	/* 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 channel *buf)
	{
	int advance, to_move;
	char from, to;

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

	to_move = buffer_len(buf);
	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 > bi_end(buf)) {
	if (to >= bi_end(buf) && to < from)
	break;
	} else if (from < bi_end(buf)) {
	if (to < from \|\| to >= bi_end(buf))
	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((unsigned char)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((unsigned char)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 channel b, int from, int to)
	{
	fprintf(o, "Dumping buffer %p\n", b);
	fprintf(o, " data=%p o=%d i=%d p=%p\n",
	b->data, b->o, b->i, b->p);

	if (!to \|\| to > buffer_len(b))
	to = buffer_len(b);

	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:
	*/