[BUG] buffer_replace2 must never change the ->w entry

This function is used to move data which is located between ->w and ->r,
so it must not touch ->w, otherwise it will displace pending data which
is before the one we're actually overwriting. The issue arises with
some pipelined responses which cause some part of the previous one to
be chopped off when removing the connection: close header, thus
corrupting last response and shifting next one. Those are detected
in the logs because the next response will be a 502 with flags PH.
This commit is contained in:
Willy Tarreau 2010-01-25 01:49:57 +01:00
parent 2a6d88dafe
commit bbfa7938bd
1 changed files with 7 additions and 3 deletions

View File

@ -178,7 +178,7 @@ int buffer_si_peekline(struct buffer *buf, char *str, int 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, w, h, lr) are recomputed to be valid after the shift.
* <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
@ -196,6 +196,9 @@ int buffer_replace(struct buffer *b, char *pos, char *end, const char *str)
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);
@ -204,7 +207,6 @@ int buffer_replace(struct buffer *b, char *pos, char *end, const char *str)
/* we only move data after the displaced zone */
if (b->r > pos) b->r += delta;
if (b->w > pos) b->w += delta;
if (b->lr > pos) b->lr += delta;
b->l += delta;
@ -230,6 +232,9 @@ int buffer_replace2(struct buffer *b, char *pos, char *end, const char *str, int
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);
@ -239,7 +244,6 @@ int buffer_replace2(struct buffer *b, char *pos, char *end, const char *str, int
/* we only move data after the displaced zone */
if (b->r > pos) b->r += delta;
if (b->w > pos) b->w += delta;
if (b->lr > pos) b->lr += delta;
b->l += delta;