blob: 43c06473bbf6f364ff3203626df13bfecebb2319 [file] [log] [blame]
/*
* 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;
}
/* 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 send_max goes down to
* zero if nobody is ready to push the remaining data.
*/
unsigned long long buffer_forward(struct buffer *buf, unsigned long long bytes)
{
unsigned int data_left;
unsigned int new_forward;
if (!bytes)
return 0;
data_left = buf->l - buf->send_max;
if (bytes <= (unsigned long long)data_left) {
buf->send_max += bytes;
buf->flags &= ~BF_OUT_EMPTY;
return bytes;
}
buf->send_max += data_left;
if (buf->send_max)
buf->flags &= ~BF_OUT_EMPTY;
if (buf->l < buffer_max_len(buf))
buf->flags &= ~BF_FULL;
else
buf->flags |= BF_FULL;
if (likely(bytes == BUF_INFINITE_FORWARD)) {
buf->to_forward = bytes;
return bytes;
}
/* 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;
new_forward = buf->to_forward + bytes - data_left;
bytes = data_left; /* 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.
*/
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;
}
/* Tries to copy character <c> into buffer <buf> after length controls. The
* send_max 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 buffer_put_char(struct buffer *buf, char c)
{
if (unlikely(buffer_input_closed(buf)))
return -2;
if (buf->flags & BF_FULL)
return -1;
*buf->r = c;
buf->l++;
if (buf->l >= buffer_max_len(buf))
buf->flags |= BF_FULL;
buf->flags |= BF_READ_PARTIAL;
buf->r++;
if (buf->r - buf->data == buf->size)
buf->r -= buf->size;
if (buf->to_forward >= 1) {
if (buf->to_forward != BUF_INFINITE_FORWARD)
buf->to_forward--;
buf->send_max++;
buf->flags &= ~BF_OUT_EMPTY;
}
buf->total++;
return 1;
}
/* Tries to copy block <blk> at once into buffer <buf> after length controls.
* The send_max 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 buffer_put_block(struct buffer *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 - buf->l)) {
/* 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(buf->r, blk, MIN(len, max));
if (len > max)
memcpy(buf->data, blk + max, len - max);
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->size;
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 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 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_get_line(struct buffer *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 = 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;
}
/* 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 buffer_skip() to
* update it.
*/
int buffer_get_block(struct buffer *buf, char *blk, int len, int offset)
{
int firstblock;
if (buf->flags & BF_SHUTW)
return -1;
if (len + offset > buf->send_max) {
if (buf->flags & (BF_SHUTW|BF_SHUTW_NOW))
return -1;
return 0;
}
firstblock = buf->data + buf->size - buf->w;
if (firstblock > offset) {
if (firstblock >= len + offset) {
memcpy(blk, buf->w + offset, len);
return len;
}
memcpy(blk, buf->w + 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, 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((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 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:
*/