Adding upstream version 2.6.12.upstream/2.6.12upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 591 insertions, 0 deletions

diff --git a/src/channel.c b/src/channel.c
new file mode 100644
index 0000000..9970575
--- /dev/null
+++ b/src/channel.c
@@ -0,0 +1,591 @@
+/*
+ * Channel management functions.
+ *
+ * Copyright 2000-2014 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 <haproxy/api.h>
+#include <haproxy/buf.h>
+#include <haproxy/channel.h>
+
+
+/* Schedule up to <bytes> more bytes to be forwarded via the channel without
+ * notifying the owner task. Any data pending in the buffer are scheduled to be
+ * sent as well, within the limit of the number of bytes to forward. This must
+ * be the only method to use to schedule bytes to be forwarded. 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 buf->o goes down to zero if nobody is ready to push the remaining data.
+ */
+unsigned long long __channel_forward(struct channel *chn, unsigned long long bytes)
+{
+	unsigned int budget;
+	unsigned int forwarded;
+
+	/* This is more of a safety measure as it's not supposed to happen in
+	 * regular code paths.
+	 */
+	if (unlikely(chn->to_forward == CHN_INFINITE_FORWARD)) {
+		c_adv(chn, ci_data(chn));
+		return bytes;
+	}
+
+	/* Bound the transferred size to a 32-bit count since all our values
+	 * are 32-bit, and we don't want to reach CHN_INFINITE_FORWARD.
+	 */
+	budget = MIN(bytes, CHN_INFINITE_FORWARD - 1);
+
+	/* transfer as much as we can of buf->i */
+	forwarded = MIN(ci_data(chn), budget);
+	c_adv(chn, forwarded);
+	budget -= forwarded;
+
+	if (!budget)
+		return forwarded;
+
+	/* Now we must ensure chn->to_forward sats below CHN_INFINITE_FORWARD,
+	 * which also implies it won't overflow. It's less operations in 64-bit.
+	 */
+	bytes = (unsigned long long)chn->to_forward + budget;
+	if (bytes >= CHN_INFINITE_FORWARD)
+		bytes = CHN_INFINITE_FORWARD - 1;
+	budget = bytes - chn->to_forward;
+
+	chn->to_forward += budget;
+	forwarded += budget;
+	return forwarded;
+}
+
+/* writes <len> bytes from message <msg> to the channel's buffer. 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 to 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 co_inject(struct channel *chn, const char *msg, int len)
+{
+	int max;
+
+	if (len == 0)
+		return -1;
+
+	if (len < 0 || len > c_size(chn)) {
+		/* 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;
+	}
+
+	c_realign_if_empty(chn);
+	max = b_contig_space(&chn->buf);
+	if (len > max)
+		return max;
+
+	memcpy(co_tail(chn), msg, len);
+	b_add(&chn->buf, len);
+	c_adv(chn, len);
+	chn->total += len;
+	return -1;
+}
+
+/* Tries to copy character <c> into the channel's buffer after some length
+ * controls. The chn->o and to_forward pointers are updated. If the channel
+ * 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). Channel flag READ_PARTIAL is updated if some data can be transferred.
+ */
+int ci_putchr(struct channel *chn, char c)
+{
+	if (unlikely(channel_input_closed(chn)))
+		return -2;
+
+	if (!channel_may_recv(chn))
+		return -1;
+
+	*ci_tail(chn) = c;
+
+	b_add(&chn->buf, 1);
+	chn->flags |= CF_READ_PARTIAL;
+
+	if (chn->to_forward >= 1) {
+		if (chn->to_forward != CHN_INFINITE_FORWARD)
+			chn->to_forward--;
+		c_adv(chn, 1);
+	}
+
+	chn->total++;
+	return 1;
+}
+
+/* Tries to copy block <blk> at once into the channel's buffer after length
+ * controls. The chn->o and to_forward pointers are updated. If the channel
+ * 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). Channel flag READ_PARTIAL is updated if some data can be
+ * transferred.
+ */
+int ci_putblk(struct channel *chn, const char *blk, int len)
+{
+	int max;
+
+	if (unlikely(channel_input_closed(chn)))
+		return -2;
+
+	if (len < 0)
+		return -3;
+
+	max = channel_recv_limit(chn);
+	if (unlikely(len > max - c_data(chn))) {
+		/* we can't write this chunk right now because the buffer is
+		 * almost full or because the block is too large. Returns
+		 * -3 if block is too large for this buffer. Or -1 if the
+		 * room left is not large enough.
+		 */
+		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 = b_contig_space(&chn->buf);
+	memcpy(ci_tail(chn), blk, MIN(len, max));
+	if (len > max)
+		memcpy(c_orig(chn), blk + max, len - max);
+
+	b_add(&chn->buf, len);
+	channel_add_input(chn, len);
+	return len;
+}
+
+/* Locates the longest part of the channel's output buffer that is composed
+ * exclusively of characters not in the <delim> set, and delimited by one of
+ * these characters, and returns the initial part and the first of such
+ * delimiters. A single escape character in <escape> may be specified so that
+ * when not 0 and found, the character that follows it is never taken as a
+ * delimiter. Note that <delim> cannot contain the zero byte, hence this
+ * function is not usable with byte zero as a delimiter.
+ *
+ * Return values :
+ *   >0 : number of bytes read. Includes the sep if present before len or end.
+ *   =0 : no sep before end found. <str> is left undefined.
+ *   <0 : no more bytes readable because output is shut.
+ * The channel status is not changed. The caller must call co_skip() to
+ * update it. One of the delimiters 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 delimiter.
+ */
+int co_getdelim(const struct channel *chn, char *str, int len, const char *delim, char escape)
+{
+	uchar delim_map[256 / 8];
+	int found, escaped;
+	uint pos, bit;
+	int ret, max;
+	uchar b;
+	char *p;
+
+	ret = 0;
+	max = len;
+
+	/* closed or empty + imminent close = -1; empty = 0 */
+	if (unlikely((chn->flags & CF_SHUTW) || channel_is_empty(chn))) {
+		if (chn->flags & (CF_SHUTW|CF_SHUTW_NOW))
+			ret = -1;
+		goto out;
+	}
+
+	p = co_head(chn);
+
+	if (max > co_data(chn)) {
+		max = co_data(chn);
+		str[max-1] = 0;
+	}
+
+	/* create the byte map */
+	memset(delim_map, 0, sizeof(delim_map));
+	while ((b = *delim)) {
+		pos = b >> 3;
+		bit = b &  7;
+		delim_map[pos] |= 1 << bit;
+		delim++;
+	}
+
+	found = escaped = 0;
+	while (max) {
+		*str++ = b = *p;
+		ret++;
+		max--;
+
+		if (escape && (escaped || *p == escape)) {
+			escaped = !escaped;
+			goto skip;
+		}
+
+		pos = b >> 3;
+		bit = b &  7;
+		if (delim_map[pos] & (1 << bit)) {
+			found = 1;
+			break;
+		}
+	skip:
+		p = b_next(&chn->buf, p);
+	}
+
+	if (ret > 0 && ret < len &&
+	    (ret < co_data(chn) || channel_may_recv(chn)) &&
+	    !found &&
+	    !(chn->flags & (CF_SHUTW|CF_SHUTW_NOW)))
+		ret = 0;
+ out:
+	if (max)
+		*str = 0;
+	return ret;
+}
+
+/* Gets one text word out of a channel's buffer from a stream connector.
+ * Return values :
+ *   >0 : number of bytes read. Includes the sep if present before len or end.
+ *   =0 : no sep before end found. <str> is left undefined.
+ *   <0 : no more bytes readable because output is shut.
+ * The channel status is not changed. The caller must call co_skip() to
+ * update it. The line separator 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 line separator.
+ */
+int co_getword(const struct channel *chn, char *str, int len, char sep)
+{
+	int ret, max;
+	char *p;
+
+	ret = 0;
+	max = len;
+
+	/* closed or empty + imminent close = -1; empty = 0 */
+	if (unlikely((chn->flags & CF_SHUTW) || channel_is_empty(chn))) {
+		if (chn->flags & (CF_SHUTW|CF_SHUTW_NOW))
+			ret = -1;
+		goto out;
+	}
+
+	p = co_head(chn);
+
+	if (max > co_data(chn)) {
+		max = co_data(chn);
+		str[max-1] = 0;
+	}
+	while (max) {
+		*str++ = *p;
+		ret++;
+		max--;
+
+		if (*p == sep)
+			break;
+		p = b_next(&chn->buf, p);
+	}
+	if (ret > 0 && ret < len &&
+	    (ret < co_data(chn) || channel_may_recv(chn)) &&
+	    *(str-1) != sep &&
+	    !(chn->flags & (CF_SHUTW|CF_SHUTW_NOW)))
+		ret = 0;
+ out:
+	if (max)
+		*str = 0;
+	return ret;
+}
+
+/* Gets one text line out of a channel's buffer from a stream connector.
+ * 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 channel status is not changed. The caller must call co_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 co_getline(const struct channel *chn, char *str, int len)
+{
+	int ret, max;
+	char *p;
+
+	ret = 0;
+	max = len;
+
+	/* closed or empty + imminent close = -1; empty = 0 */
+	if (unlikely((chn->flags & CF_SHUTW) || channel_is_empty(chn))) {
+		if (chn->flags & (CF_SHUTW|CF_SHUTW_NOW))
+			ret = -1;
+		goto out;
+	}
+
+	p = co_head(chn);
+
+	if (max > co_data(chn)) {
+		max = co_data(chn);
+		str[max-1] = 0;
+	}
+	while (max) {
+		*str++ = *p;
+		ret++;
+		max--;
+
+		if (*p == '\n')
+			break;
+		p = b_next(&chn->buf, p);
+	}
+	if (ret > 0 && ret < len &&
+	    (ret < co_data(chn) || channel_may_recv(chn)) &&
+	    *(str-1) != '\n' &&
+	    !(chn->flags & (CF_SHUTW|CF_SHUTW_NOW)))
+		ret = 0;
+ out:
+	if (max)
+		*str = 0;
+	return ret;
+}
+
+/* Gets one char of data from a channel's buffer,
+ * Return values :
+ *    1 : number of bytes read, equal to requested size.
+ *   =0 : not enough data available. <c> is left undefined.
+ *   <0 : no more bytes readable because output is shut.
+ * The channel status is not changed. The caller must call co_skip() to
+ * update it.
+ */
+int co_getchar(const struct channel *chn, char *c)
+{
+	if (chn->flags & CF_SHUTW)
+		return -1;
+
+	if (unlikely(co_data(chn) == 0)) {
+		if (chn->flags & (CF_SHUTW|CF_SHUTW_NOW))
+			return -1;
+		return 0;
+	}
+
+	*c = *(co_head(chn));
+	return 1;
+}
+
+/* Gets one full block of data at once from a channel's 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 channel status is not changed. The caller must call co_skip() to
+ * update it.
+ */
+int co_getblk(const struct channel *chn, char *blk, int len, int offset)
+{
+	if (chn->flags & CF_SHUTW)
+		return -1;
+
+	if (len + offset > co_data(chn)) {
+		if (chn->flags & (CF_SHUTW|CF_SHUTW_NOW))
+			return -1;
+		return 0;
+	}
+
+	return b_getblk(&chn->buf, blk, len, offset);
+}
+
+/* Gets one or two blocks of data at once from a channel's output buffer.
+ * Return values :
+ *   >0 : number of blocks filled (1 or 2). blk1 is always filled before blk2.
+ *   =0 : not enough data available. <blk*> are left undefined.
+ *   <0 : no more bytes readable because output is shut.
+ * The channel status is not changed. The caller must call co_skip() to
+ * update it. Unused buffers are left in an undefined state.
+ */
+int co_getblk_nc(const struct channel *chn, const char **blk1, size_t *len1, const char **blk2, size_t *len2)
+{
+	if (unlikely(co_data(chn) == 0)) {
+		if (chn->flags & (CF_SHUTW|CF_SHUTW_NOW))
+			return -1;
+		return 0;
+	}
+
+	return b_getblk_nc(&chn->buf, blk1, len1, blk2, len2, 0, co_data(chn));
+}
+
+/* Gets one text line out of a channel's output buffer from a stream connector.
+ * Return values :
+ *   >0 : number of blocks returned (1 or 2). blk1 is always filled before blk2.
+ *   =0 : not enough data available.
+ *   <0 : no more bytes readable because output is shut.
+ * 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'. Unused buffers are left in an undefined state.
+ */
+int co_getline_nc(const struct channel *chn,
+                  const char **blk1, size_t *len1,
+                  const char **blk2, size_t *len2)
+{
+	int retcode;
+	int l;
+
+	retcode = co_getblk_nc(chn, blk1, len1, blk2, len2);
+	if (unlikely(retcode <= 0))
+		return retcode;
+
+	for (l = 0; l < *len1 && (*blk1)[l] != '\n'; l++);
+	if (l < *len1 && (*blk1)[l] == '\n') {
+		*len1 = l + 1;
+		return 1;
+	}
+
+	if (retcode >= 2) {
+		for (l = 0; l < *len2 && (*blk2)[l] != '\n'; l++);
+		if (l < *len2 && (*blk2)[l] == '\n') {
+			*len2 = l + 1;
+			return 2;
+		}
+	}
+
+	if (chn->flags & (CF_SHUTW|CF_SHUTW_NOW)) {
+		/* If we have found no LF and the buffer is shut, then
+		 * the resulting string is made of the concatenation of
+		 * the pending blocks (1 or 2).
+		 */
+		return retcode;
+	}
+
+	/* No LF yet and not shut yet */
+	return 0;
+}
+
+/* Gets one full block of data at once from a channel's input buffer.
+ * This function can return the data slitted in one or two blocks.
+ * Return values :
+ *   >0 : number of blocks returned (1 or 2). blk1 is always filled before blk2.
+ *   =0 : not enough data available.
+ *   <0 : no more bytes readable because input is shut.
+ */
+int ci_getblk_nc(const struct channel *chn,
+                 char **blk1, size_t *len1,
+                 char **blk2, size_t *len2)
+{
+	if (unlikely(ci_data(chn) == 0)) {
+		if (chn->flags & CF_SHUTR)
+			return -1;
+		return 0;
+	}
+
+	if (unlikely(ci_head(chn) + ci_data(chn) > c_wrap(chn))) {
+		*blk1 = ci_head(chn);
+		*len1 = c_wrap(chn) - ci_head(chn);
+		*blk2 = c_orig(chn);
+		*len2 = ci_data(chn) - *len1;
+		return 2;
+	}
+
+	*blk1 = ci_head(chn);
+	*len1 = ci_data(chn);
+	return 1;
+}
+
+/* Gets one text line out of a channel's input buffer from a stream connector.
+ * Return values :
+ *   >0 : number of blocks returned (1 or 2). blk1 is always filled before blk2.
+ *   =0 : not enough data available.
+ *   <0 : no more bytes readable because output is shut.
+ * The '\n' is waited for as long as neither the buffer nor the input are
+ * full. If either of them is full, the string may be returned as is, without
+ * the '\n'. Unused buffers are left in an undefined state.
+ */
+int ci_getline_nc(const struct channel *chn,
+                  char **blk1, size_t *len1,
+                  char **blk2, size_t *len2)
+{
+	int retcode;
+	int l;
+
+	retcode = ci_getblk_nc(chn, blk1, len1, blk2, len2);
+	if (unlikely(retcode <= 0))
+		return retcode;
+
+	for (l = 0; l < *len1 && (*blk1)[l] != '\n'; l++);
+	if (l < *len1 && (*blk1)[l] == '\n') {
+		*len1 = l + 1;
+		return 1;
+	}
+
+	if (retcode >= 2) {
+		for (l = 0; l < *len2 && (*blk2)[l] != '\n'; l++);
+		if (l < *len2 && (*blk2)[l] == '\n') {
+			*len2 = l + 1;
+			return 2;
+		}
+	}
+
+	if (chn->flags & CF_SHUTW) {
+		/* If we have found no LF and the buffer is shut, then
+		 * the resulting string is made of the concatenation of
+		 * the pending blocks (1 or 2).
+		 */
+		return retcode;
+	}
+
+	/* No LF yet and not shut yet */
+	return 0;
+}
+
+/* Inserts <str> followed by "\r\n" at position <pos> relative to channel <c>'s
+ * input head. The <len> argument informs about the length of string <str> so
+ * that we don't have to measure it. <str> must be a valid pointer and must not
+ * include the trailing "\r\n".
+ *
+ * The number of bytes added is returned on success. 0 is returned on failure.
+ */
+int ci_insert_line2(struct channel *c, int pos, const char *str, int len)
+{
+	struct buffer *b = &c->buf;
+	char *dst = c_ptr(c, pos);
+	int delta;
+
+	delta = len + 2;
+
+	if (__b_tail(b) + delta >= b_wrap(b))
+		return 0;  /* no space left */
+
+	if (b_data(b) &&
+	    b_tail(b) + delta > b_head(b) &&
+	    b_head(b) >= b_tail(b))
+		return 0;  /* no space left before wrapping data */
+
+	/* first, protect the end of the buffer */
+	memmove(dst + delta, dst, b_tail(b) - dst);
+
+	/* now, copy str over dst */
+	memcpy(dst, str, len);
+	dst[len] = '\r';
+	dst[len + 1] = '\n';
+
+	b_add(b, delta);
+	return delta;
+}
+
+/*
+ * Local variables:
+ *  c-indent-level: 8
+ *  c-basic-offset: 8
+ * End:
+ */