diff options
Diffstat (limited to 'src/htx.c')
| -rw-r--r-- | src/htx.c | 1099 |
1 files changed, 1099 insertions, 0 deletions
diff --git a/src/htx.c b/src/htx.c new file mode 100644 index 0000000..feb7eec --- /dev/null +++ b/src/htx.c @@ -0,0 +1,1099 @@ +/* + * internal HTTP message + * + * Copyright 2018 HAProxy Technologies, Christopher Faulet <cfaulet@haproxy.com> + * + * 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 <haproxy/chunk.h> +#include <haproxy/htx.h> +#include <haproxy/net_helper.h> + +struct htx htx_empty = { .size = 0, .data = 0, .head = -1, .tail = -1, .first = -1 }; + +/* tests show that 63% of these calls are for 64-bit chunks, so better avoid calling + * memcpy() for that! + */ +static inline __attribute__((always_inline)) void htx_memcpy(void *dst, void *src, size_t len) +{ + if (likely(len == 8)) + write_u64(dst, read_u64(src)); + else + memcpy(dst, src, len); +} + +/* Defragments an HTX message. It removes unused blocks and unwraps the payloads + * part. A temporary buffer is used to do so. This function never fails. Most of + * time, we need keep a ref on a specific HTX block. Thus is <blk> is set, the + * pointer on its new position, after defrag, is returned. In addition, if the + * size of the block must be altered, <blkinfo> info must be provided (!= + * 0). But in this case, it remains the caller responsibility to update the + * block content. + */ +/* TODO: merge data blocks into one */ +struct htx_blk *htx_defrag(struct htx *htx, struct htx_blk *blk, uint32_t blkinfo) +{ + struct buffer *chunk = get_trash_chunk(); + struct htx *tmp = htxbuf(chunk); + struct htx_blk *newblk, *oldblk; + uint32_t new, old, blkpos; + uint32_t addr, blksz; + int32_t first = -1; + + if (htx->head == -1) + return NULL; + + blkpos = -1; + + new = 0; + addr = 0; + tmp->size = htx->size; + tmp->data = 0; + + /* start from the head */ + for (old = htx_get_head(htx); old != -1; old = htx_get_next(htx, old)) { + oldblk = htx_get_blk(htx, old); + if (htx_get_blk_type(oldblk) == HTX_BLK_UNUSED) + continue; + + blksz = htx_get_blksz(oldblk); + htx_memcpy((void *)tmp->blocks + addr, htx_get_blk_ptr(htx, oldblk), blksz); + + /* update the start-line position */ + if (htx->first == old) + first = new; + + newblk = htx_get_blk(tmp, new); + newblk->addr = addr; + newblk->info = oldblk->info; + + /* if <blk> is defined, save its new position */ + if (blk != NULL && blk == oldblk) { + if (blkinfo) + newblk->info = blkinfo; + blkpos = new; + } + + blksz = htx_get_blksz(newblk); + addr += blksz; + tmp->data += blksz; + new++; + } + + htx->data = tmp->data; + htx->first = first; + htx->head = 0; + htx->tail = new - 1; + htx->head_addr = htx->end_addr = 0; + htx->tail_addr = addr; + htx->flags &= ~HTX_FL_FRAGMENTED; + htx_memcpy((void *)htx->blocks, (void *)tmp->blocks, htx->size); + + return ((blkpos == -1) ? NULL : htx_get_blk(htx, blkpos)); +} + +/* Degragments HTX blocks of an HTX message. Payloads part is keep untouched + * here. This function will move back all blocks starting at the position 0, + * removing unused blocks. It must never be called with an empty message. + */ +static void htx_defrag_blks(struct htx *htx) +{ + int32_t pos, new; + + new = 0; + for (pos = htx_get_head(htx); pos != -1; pos = htx_get_next(htx, pos)) { + struct htx_blk *posblk, *newblk; + + if (pos == new) { + new++; + continue; + } + + posblk = htx_get_blk(htx, pos); + if (htx_get_blk_type(posblk) == HTX_BLK_UNUSED) + continue; + + if (htx->first == pos) + htx->first = new; + newblk = htx_get_blk(htx, new++); + newblk->info = posblk->info; + newblk->addr = posblk->addr; + } + BUG_ON(!new); + htx->head = 0; + htx->tail = new - 1; +} + +/* Reserves a new block in the HTX message <htx> with a content of <blksz> + * bytes. If there is not enough space, NULL is returned. Otherwise the reserved + * block is returned and the HTX message is updated. Space for this new block is + * reserved in the HTX message. But it is the caller responsibility to set right + * info in the block to reflect the stored data. + */ +static struct htx_blk *htx_reserve_nxblk(struct htx *htx, uint32_t blksz) +{ + struct htx_blk *blk; + uint32_t tail, headroom, tailroom; + + if (blksz > htx_free_data_space(htx)) + return NULL; /* full */ + + if (htx->head == -1) { + /* Empty message */ + htx->head = htx->tail = htx->first = 0; + blk = htx_get_blk(htx, htx->tail); + blk->addr = 0; + htx->data = blksz; + htx->tail_addr = blksz; + return blk; + } + + /* Find the block's position. First, we try to get the next position in + * the message, increasing the tail by one. If this position is not + * available with some holes, we try to defrag the blocks without + * touching their paylood. If it is impossible, we fully defrag the + * message. + */ + tail = htx->tail + 1; + if (htx_pos_to_addr(htx, tail) >= htx->tail_addr) + ; + else if (htx->head > 0) { + htx_defrag_blks(htx); + tail = htx->tail + 1; + BUG_ON(htx_pos_to_addr(htx, tail) < htx->tail_addr); + } + else + goto defrag; + + /* Now, we have found the block's position. Try to find where to put its + * payload. The free space is split in two areas: + * + * * The free space in front of the blocks table. This one is used if and + * only if the other one was not used yet. + * + * * The free space at the beginning of the message. Once this one is + * used, the other one is never used again, until the next defrag. + */ + headroom = (htx->end_addr - htx->head_addr); + tailroom = (!htx->head_addr ? htx_pos_to_addr(htx, tail) - htx->tail_addr : 0); + BUG_ON((int32_t)headroom < 0); + BUG_ON((int32_t)tailroom < 0); + + if (blksz <= tailroom) { + blk = htx_get_blk(htx, tail); + blk->addr = htx->tail_addr; + htx->tail_addr += blksz; + } + else if (blksz <= headroom) { + blk = htx_get_blk(htx, tail); + blk->addr = htx->head_addr; + htx->head_addr += blksz; + } + else { + defrag: + /* need to defragment the message before inserting upfront */ + htx_defrag(htx, NULL, 0); + tail = htx->tail + 1; + blk = htx_get_blk(htx, tail); + blk->addr = htx->tail_addr; + htx->tail_addr += blksz; + } + + htx->tail = tail; + htx->data += blksz; + /* Set first position if not already set */ + if (htx->first == -1) + htx->first = tail; + + BUG_ON((int32_t)htx->tail_addr < 0); + BUG_ON((int32_t)htx->head_addr < 0); + BUG_ON(htx->end_addr > htx->tail_addr); + BUG_ON(htx->head_addr > htx->end_addr); + + return blk; +} + +/* Prepares the block to an expansion of its payload. The payload will be + * expanded by <delta> bytes and we need find where this expansion will be + * performed. It can be a compression if <delta> is negative. This function only + * updates all addresses. The caller have the responsibility to perform the + * expansion and update the block and the HTX message accordingly. No error must + * occur. It returns following values: + * + * 0: The expansion cannot be performed, there is not enough space. + * + * 1: the expansion must be performed in place, there is enough space after + * the block's payload to handle it. This is especially true if it is a + * compression and not an expansion. + * + * 2: the block's payload must be moved at the new block address before doing + * the expansion. + * + * 3: the HTX message message must be defragmented + */ +static int htx_prepare_blk_expansion(struct htx *htx, struct htx_blk *blk, int32_t delta) +{ + uint32_t sz, tailroom, headroom; + int ret = 3; + + BUG_ON(htx->head == -1); + + headroom = (htx->end_addr - htx->head_addr); + tailroom = (htx_pos_to_addr(htx, htx->tail) - htx->tail_addr); + BUG_ON((int32_t)headroom < 0); + BUG_ON((int32_t)tailroom < 0); + + sz = htx_get_blksz(blk); + if (delta <= 0) { + /* It is a compression, it can be performed in place */ + if (blk->addr+sz == htx->tail_addr) + htx->tail_addr += delta; + else if (blk->addr+sz == htx->head_addr) + htx->head_addr += delta; + ret = 1; + } + else if (delta > htx_free_space(htx)) { + /* There is not enough space to handle the expansion */ + ret = 0; + } + else if (blk->addr+sz == htx->tail_addr) { + /* The block's payload is just before the tail room */ + if (delta < tailroom) { + /* Expand the block's payload */ + htx->tail_addr += delta; + ret = 1; + } + else if ((sz + delta) < headroom) { + uint32_t oldaddr = blk->addr; + + /* Move the block's payload into the headroom */ + blk->addr = htx->head_addr; + htx->tail_addr -= sz; + htx->head_addr += sz + delta; + if (oldaddr == htx->end_addr) { + if (htx->end_addr == htx->tail_addr) { + htx->tail_addr = htx->head_addr; + htx->head_addr = htx->end_addr = 0; + } + else + htx->end_addr += sz; + } + ret = 2; + } + } + else if (blk->addr+sz == htx->head_addr) { + /* The block's payload is just before the head room */ + if (delta < headroom) { + /* Expand the block's payload */ + htx->head_addr += delta; + ret = 1; + } + } + else { + /* The block's payload is not at the rooms edge */ + if (!htx->head_addr && sz+delta < tailroom) { + /* Move the block's payload into the tailroom */ + if (blk->addr == htx->end_addr) + htx->end_addr += sz; + blk->addr = htx->tail_addr; + htx->tail_addr += sz + delta; + ret = 2; + } + else if (sz+delta < headroom) { + /* Move the block's payload into the headroom */ + if (blk->addr == htx->end_addr) + htx->end_addr += sz; + blk->addr = htx->head_addr; + htx->head_addr += sz + delta; + ret = 2; + } + } + /* Otherwise defrag the HTX message */ + + BUG_ON((int32_t)htx->tail_addr < 0); + BUG_ON((int32_t)htx->head_addr < 0); + BUG_ON(htx->end_addr > htx->tail_addr); + BUG_ON(htx->head_addr > htx->end_addr); + return ret; +} + +/* Adds a new block of type <type> in the HTX message <htx>. Its content size is + * passed but it is the caller responsibility to do the copy. + */ +struct htx_blk *htx_add_blk(struct htx *htx, enum htx_blk_type type, uint32_t blksz) +{ + struct htx_blk *blk; + + BUG_ON(blksz >= 256 << 20); + blk = htx_reserve_nxblk(htx, blksz); + if (!blk) + return NULL; + BUG_ON(blk->addr > htx->size); + + blk->info = (type << 28); + return blk; +} + +/* Removes the block <blk> from the HTX message <htx>. The function returns the + * block following <blk> or NULL if <blk> is the last block or the last inserted + * one. + */ +struct htx_blk *htx_remove_blk(struct htx *htx, struct htx_blk *blk) +{ + enum htx_blk_type type; + uint32_t pos, addr, sz; + + BUG_ON(!blk || htx->head == -1); + + /* This is the last block in use */ + if (htx->head == htx->tail) { + uint32_t flags = (htx->flags & ~HTX_FL_FRAGMENTED); /* Preserve flags except FRAGMENTED */ + + htx_reset(htx); + htx->flags = flags; /* restore flags */ + return NULL; + } + + type = htx_get_blk_type(blk); + pos = htx_get_blk_pos(htx, blk); + sz = htx_get_blksz(blk); + addr = blk->addr; + if (type != HTX_BLK_UNUSED) { + /* Mark the block as unused, decrement allocated size */ + htx->data -= htx_get_blksz(blk); + blk->info = ((uint32_t)HTX_BLK_UNUSED << 28); + } + + /* There is at least 2 blocks, so tail is always > 0 */ + if (pos == htx->head) { + /* move the head forward */ + htx->head++; + } + else if (pos == htx->tail) { + /* remove the tail. this was the last inserted block so + * return NULL. */ + htx->tail--; + blk = NULL; + goto end; + } + else + htx->flags |= HTX_FL_FRAGMENTED; + + blk = htx_get_blk(htx, pos+1); + + end: + if (pos == htx->first) + htx->first = (blk ? htx_get_blk_pos(htx, blk) : -1); + + if (htx->head == htx->tail) { + /* If there is just one block in the HTX message, free space can + * be adjusted. This operation could save some defrags. */ + struct htx_blk *lastblk = htx_get_blk(htx, htx->tail); + + htx->head_addr = 0; + htx->end_addr = lastblk->addr; + htx->tail_addr = lastblk->addr+htx->data; + } + else { + if (addr+sz == htx->tail_addr) + htx->tail_addr = addr; + else if (addr+sz == htx->head_addr) + htx->head_addr = addr; + if (addr == htx->end_addr) { + if (htx->tail_addr == htx->end_addr) { + htx->tail_addr = htx->head_addr; + htx->head_addr = htx->end_addr = 0; + } + else + htx->end_addr += sz; + } + } + + BUG_ON((int32_t)htx->tail_addr < 0); + BUG_ON((int32_t)htx->head_addr < 0); + BUG_ON(htx->end_addr > htx->tail_addr); + BUG_ON(htx->head_addr > htx->end_addr); + return blk; +} + +/* Looks for the HTX block containing the offset <offset>, starting at the HTX + * message's head. The function returns an htx_ret with the found HTX block and + * the position inside this block where the offset is. If the offset <offset> is + * outside of the HTX message, htx_ret.blk is set to NULL. + */ +struct htx_ret htx_find_offset(struct htx *htx, uint32_t offset) +{ + struct htx_blk *blk; + struct htx_ret htxret = { .blk = NULL, .ret = 0 }; + + if (offset >= htx->data) + return htxret; + + for (blk = htx_get_head_blk(htx); blk && offset; blk = htx_get_next_blk(htx, blk)) { + uint32_t sz = htx_get_blksz(blk); + + if (offset < sz) + break; + offset -= sz; + } + htxret.blk = blk; + htxret.ret = offset; + return htxret; +} + +/* Removes all blocks after the one containing the offset <offset>. This last + * one may be truncated if it is a DATA block. + */ +void htx_truncate(struct htx *htx, uint32_t offset) +{ + struct htx_blk *blk; + struct htx_ret htxret = htx_find_offset(htx, offset); + + blk = htxret.blk; + if (blk && htxret.ret && htx_get_blk_type(blk) == HTX_BLK_DATA) { + htx_change_blk_value_len(htx, blk, htxret.ret); + blk = htx_get_next_blk(htx, blk); + } + while (blk) + blk = htx_remove_blk(htx, blk); +} + +/* Drains <count> bytes from the HTX message <htx>. If the last block is a DATA + * block, it will be cut if necessary. Others blocks will be removed at once if + * <count> is large enough. The function returns an htx_ret with the first block + * remaining in the message and the amount of data drained. If everything is + * removed, htx_ret.blk is set to NULL. + */ +struct htx_ret htx_drain(struct htx *htx, uint32_t count) +{ + struct htx_blk *blk; + struct htx_ret htxret = { .blk = NULL, .ret = 0 }; + + if (count == htx->data) { + uint32_t flags = (htx->flags & ~HTX_FL_FRAGMENTED); /* Preserve flags except FRAGMENTED */ + + htx_reset(htx); + htx->flags = flags; /* restore flags */ + htxret.ret = count; + return htxret; + } + + blk = htx_get_head_blk(htx); + while (count && blk) { + uint32_t sz = htx_get_blksz(blk); + enum htx_blk_type type = htx_get_blk_type(blk); + + /* Ignore unused block */ + if (type == HTX_BLK_UNUSED) + goto next; + + if (sz > count) { + if (type == HTX_BLK_DATA) { + htx_cut_data_blk(htx, blk, count); + htxret.ret += count; + } + break; + } + count -= sz; + htxret.ret += sz; + next: + blk = htx_remove_blk(htx, blk); + } + htxret.blk = blk; + + return htxret; +} + +/* Tries to append data to the last inserted block, if the type matches and if + * there is enough space to take it all. If the space wraps, the buffer is + * defragmented and a new block is inserted. If an error occurred, NULL is + * returned. Otherwise, on success, the updated block (or the new one) is + * returned. Due to its nature this function can be expensive and should be + * avoided whenever possible. + */ +struct htx_blk *htx_add_data_atonce(struct htx *htx, struct ist data) +{ + struct htx_blk *blk, *tailblk; + void *ptr; + uint32_t len, sz, tailroom, headroom; + + if (htx->head == -1) + goto add_new_block; + + /* Not enough space to store data */ + if (data.len > htx_free_data_space(htx)) + return NULL; + + /* get the tail block and its size */ + tailblk = htx_get_tail_blk(htx); + if (tailblk == NULL) + goto add_new_block; + sz = htx_get_blksz(tailblk); + + /* Don't try to append data if the last inserted block is not of the + * same type */ + if (htx_get_blk_type(tailblk) != HTX_BLK_DATA) + goto add_new_block; + + /* + * Same type and enough space: append data + */ + headroom = (htx->end_addr - htx->head_addr); + tailroom = (htx_pos_to_addr(htx, htx->tail) - htx->tail_addr); + BUG_ON((int32_t)headroom < 0); + BUG_ON((int32_t)tailroom < 0); + + len = data.len; + if (tailblk->addr+sz == htx->tail_addr) { + if (data.len <= tailroom) + goto append_data; + else if (!htx->head_addr) { + len = tailroom; + goto append_data; + } + } + else if (tailblk->addr+sz == htx->head_addr && data.len <= headroom) + goto append_data; + + goto add_new_block; + + append_data: + /* Append data and update the block itself */ + ptr = htx_get_blk_ptr(htx, tailblk); + htx_memcpy(ptr+sz, data.ptr, len); + htx_change_blk_value_len(htx, tailblk, sz+len); + + if (data.len == len) { + blk = tailblk; + goto end; + } + data = istadv(data, len); + + add_new_block: + blk = htx_add_blk(htx, HTX_BLK_DATA, data.len); + if (!blk) + return NULL; + + blk->info += data.len; + htx_memcpy(htx_get_blk_ptr(htx, blk), data.ptr, data.len); + + end: + BUG_ON((int32_t)htx->tail_addr < 0); + BUG_ON((int32_t)htx->head_addr < 0); + BUG_ON(htx->end_addr > htx->tail_addr); + BUG_ON(htx->head_addr > htx->end_addr); + return blk; +} + +/* Replaces a value part of a block by a new one. The new part can be smaller or + * larger than the old one. This function works for any kind of block with + * attached data. It returns the new block on success, otherwise it returns + * NULL. + */ +struct htx_blk *htx_replace_blk_value(struct htx *htx, struct htx_blk *blk, + const struct ist old, const struct ist new) +{ + struct ist n, v; + int32_t delta; + int ret; + + n = htx_get_blk_name(htx, blk); + v = htx_get_blk_value(htx, blk); + delta = new.len - old.len; + ret = htx_prepare_blk_expansion(htx, blk, delta); + if (!ret) + return NULL; /* not enough space */ + + if (ret == 1) { /* Replace in place */ + if (delta <= 0) { + /* compression: copy new data first then move the end */ + htx_memcpy(old.ptr, new.ptr, new.len); + memmove(old.ptr + new.len, istend(old), + istend(v) - istend(old)); + } + else { + /* expansion: move the end first then copy new data */ + memmove(old.ptr + new.len, istend(old), + istend(v) - istend(old)); + htx_memcpy(old.ptr, new.ptr, new.len); + } + + /* set the new block size and update HTX message */ + htx_set_blk_value_len(blk, v.len + delta); + htx->data += delta; + } + else if (ret == 2) { /* New address but no defrag */ + void *ptr = htx_get_blk_ptr(htx, blk); + + /* Copy the name, if any */ + htx_memcpy(ptr, n.ptr, n.len); + ptr += n.len; + + /* Copy value before old part, if any */ + htx_memcpy(ptr, v.ptr, old.ptr - v.ptr); + ptr += old.ptr - v.ptr; + + /* Copy new value */ + htx_memcpy(ptr, new.ptr, new.len); + ptr += new.len; + + /* Copy value after old part, if any */ + htx_memcpy(ptr, istend(old), istend(v) - istend(old)); + + /* set the new block size and update HTX message */ + htx_set_blk_value_len(blk, v.len + delta); + htx->data += delta; + } + else { /* Do a degrag first (it is always an expansion) */ + struct htx_blk tmpblk; + int32_t offset; + + /* use tmpblk to set new block size before defrag and to compute + * the offset after defrag + */ + tmpblk.addr = blk->addr; + tmpblk.info = blk->info; + htx_set_blk_value_len(&tmpblk, v.len + delta); + + /* htx_defrag() will take care to update the block size and the htx message */ + blk = htx_defrag(htx, blk, tmpblk.info); + + /* newblk is now the new HTX block. Compute the offset to copy/move payload */ + offset = blk->addr - tmpblk.addr; + + /* move the end first and copy new data + */ + memmove(old.ptr + offset + new.len, old.ptr + offset + old.len, + istend(v) - istend(old)); + htx_memcpy(old.ptr + offset, new.ptr, new.len); + } + return blk; +} + +/* Transfer HTX blocks from <src> to <dst>, stopping on the first block of the + * type <mark> (typically EOH or EOT) or when <count> bytes were moved + * (including payload and meta-data). It returns the number of bytes moved and + * the last HTX block inserted in <dst>. + */ +struct htx_ret htx_xfer_blks(struct htx *dst, struct htx *src, uint32_t count, + enum htx_blk_type mark) +{ + struct htx_blk *blk, *dstblk; + struct htx_blk *srcref, *dstref; + enum htx_blk_type type; + uint32_t info, max, sz, ret; + + ret = htx_used_space(dst); + srcref = dstref = dstblk = NULL; + + /* blocks are not removed yet from <src> HTX message to be able to + * rollback the transfer if all the headers/trailers are not copied. + */ + for (blk = htx_get_head_blk(src); blk && count; blk = htx_get_next_blk(src, blk)) { + type = htx_get_blk_type(blk); + + /* Ignore unused block */ + if (type == HTX_BLK_UNUSED) + continue; + + + max = htx_get_max_blksz(dst, count); + if (!max) + break; + + sz = htx_get_blksz(blk); + info = blk->info; + if (sz > max) { + /* Only DATA blocks can be partially xferred */ + if (type != HTX_BLK_DATA) + break; + sz = max; + info = (type << 28) + sz; + } + + dstblk = htx_reserve_nxblk(dst, sz); + if (!dstblk) + break; + dstblk->info = info; + htx_memcpy(htx_get_blk_ptr(dst, dstblk), htx_get_blk_ptr(src, blk), sz); + + count -= sizeof(dstblk) + sz; + if (blk->info != info) { + /* Partial xfer: don't remove <blk> from <src> but + * resize its content */ + htx_cut_data_blk(src, blk, sz); + break; + } + + if (type == mark) { + blk = htx_get_next_blk(src, blk); + srcref = dstref = NULL; + break; + } + + /* Save <blk> to <srcref> and <dstblk> to <dstref> when we start + * to xfer headers or trailers. When EOH/EOT block is reached, + * both are reset. It is mandatory to be able to rollback a + * partial transfer. + */ + if (!srcref && !dstref && + (type == HTX_BLK_REQ_SL || type == HTX_BLK_RES_SL || type == HTX_BLK_TLR)) { + srcref = blk; + dstref = dstblk; + } + else if (type == HTX_BLK_EOH || type == HTX_BLK_EOT) + srcref = dstref = NULL; + } + + if (unlikely(dstref)) { + /* Headers or trailers part was partially xferred, so rollback + * the copy by removing all block between <dstref> and <dstblk>, + * both included. <dstblk> may be NULL. + */ + while (dstref && dstref != dstblk) + dstref = htx_remove_blk(dst, dstref); + if (dstblk) + htx_remove_blk(dst, dstblk); + + /* <dst> HTX message is empty, it means the headers or trailers + * part is too big to be copied at once. + */ + if (htx_is_empty(dst)) + src->flags |= HTX_FL_PARSING_ERROR; + } + + /* Now, remove xferred blocks from <src> htx message */ + if (!blk && !srcref) { + /* End of src reached, all blocks were consumed, drain all data */ + htx_drain(src, src->data); + } + else { + /* Remove all block from the head to <blk>, or <srcref> if defined, excluded */ + srcref = (srcref ? srcref : blk); + for (blk = htx_get_head_blk(src); blk && blk != srcref; blk = htx_remove_blk(src, blk)); + } + + end: + ret = htx_used_space(dst) - ret; + return (struct htx_ret){.ret = ret, .blk = dstblk}; +} + +/* Replaces an header by a new one. The new header can be smaller or larger than + * the old one. It returns the new block on success, otherwise it returns NULL. + * The header name is always lower cased. + */ +struct htx_blk *htx_replace_header(struct htx *htx, struct htx_blk *blk, + const struct ist name, const struct ist value) +{ + enum htx_blk_type type; + void *ptr; + int32_t delta; + int ret; + + type = htx_get_blk_type(blk); + if (type != HTX_BLK_HDR) + return NULL; + + delta = name.len + value.len - htx_get_blksz(blk); + ret = htx_prepare_blk_expansion(htx, blk, delta); + if (!ret) + return NULL; /* not enough space */ + + + /* Replace in place or at a new address is the same. We replace all the + * header (name+value). Only take care to defrag the message if + * necessary. */ + if (ret == 3) + blk = htx_defrag(htx, blk, (type << 28) + (value.len << 8) + name.len); + else { + /* Set the new block size and update HTX message */ + blk->info = (type << 28) + (value.len << 8) + name.len; + htx->data += delta; + } + + /* Finally, copy data. */ + ptr = htx_get_blk_ptr(htx, blk); + ist2bin_lc(ptr, name); + htx_memcpy(ptr + name.len, value.ptr, value.len); + return blk; +} + +/* Replaces the parts of the start-line. It returns the new start-line on + * success, otherwise it returns NULL. It is the caller responsibility to update + * sl->info, if necessary. + */ +struct htx_sl *htx_replace_stline(struct htx *htx, struct htx_blk *blk, const struct ist p1, + const struct ist p2, const struct ist p3) +{ + enum htx_blk_type type; + struct htx_sl *sl; + struct htx_sl tmp; /* used to save sl->info and sl->flags */ + uint32_t sz; + int32_t delta; + int ret; + + type = htx_get_blk_type(blk); + if (type != HTX_BLK_REQ_SL && type != HTX_BLK_RES_SL) + return NULL; + + /* Save start-line info and flags */ + sl = htx_get_blk_ptr(htx, blk); + tmp.info = sl->info; + tmp.flags = sl->flags; + + sz = htx_get_blksz(blk); + delta = sizeof(*sl) + p1.len + p2.len + p3.len - sz; + ret = htx_prepare_blk_expansion(htx, blk, delta); + if (!ret) + return NULL; /* not enough space */ + + /* Replace in place or at a new address is the same. We replace all the + * start-line. Only take care to defrag the message if necessary. */ + if (ret == 3) { + blk = htx_defrag(htx, blk, (type << 28) + sz + delta); + } + else { + /* Set the new block size and update HTX message */ + blk->info = (type << 28) + sz + delta; + htx->data += delta; + } + + /* Restore start-line info and flags and copy parts of the start-line */ + sl = htx_get_blk_ptr(htx, blk); + sl->info = tmp.info; + sl->flags = tmp.flags; + + HTX_SL_P1_LEN(sl) = p1.len; + HTX_SL_P2_LEN(sl) = p2.len; + HTX_SL_P3_LEN(sl) = p3.len; + + htx_memcpy(HTX_SL_P1_PTR(sl), p1.ptr, p1.len); + htx_memcpy(HTX_SL_P2_PTR(sl), p2.ptr, p2.len); + htx_memcpy(HTX_SL_P3_PTR(sl), p3.ptr, p3.len); + + return sl; +} + +/* Reserves the maximum possible size for an HTX data block, by extending an + * existing one or by creating a now one. It returns a compound result with the + * HTX block and the position where new data must be inserted (0 for a new + * block). If an error occurs or if there is no space left, NULL is returned + * instead of a pointer on an HTX block. + */ +struct htx_ret htx_reserve_max_data(struct htx *htx) +{ + struct htx_blk *blk, *tailblk; + uint32_t sz, room; + int32_t len = htx_free_data_space(htx); + + if (htx->head == -1) + goto rsv_new_block; + + if (!len) + return (struct htx_ret){.ret = 0, .blk = NULL}; + + /* get the tail and head block */ + tailblk = htx_get_tail_blk(htx); + if (tailblk == NULL) + goto rsv_new_block; + sz = htx_get_blksz(tailblk); + + /* Don't try to append data if the last inserted block is not of the + * same type */ + if (htx_get_blk_type(tailblk) != HTX_BLK_DATA) + goto rsv_new_block; + + /* + * Same type and enough space: append data + */ + if (!htx->head_addr) { + if (tailblk->addr+sz != htx->tail_addr) + goto rsv_new_block; + room = (htx_pos_to_addr(htx, htx->tail) - htx->tail_addr); + } + else { + if (tailblk->addr+sz != htx->head_addr) + goto rsv_new_block; + room = (htx->end_addr - htx->head_addr); + } + BUG_ON((int32_t)room < 0); + if (room < len) + len = room; + +append_data: + htx_change_blk_value_len(htx, tailblk, sz+len); + + BUG_ON((int32_t)htx->tail_addr < 0); + BUG_ON((int32_t)htx->head_addr < 0); + BUG_ON(htx->end_addr > htx->tail_addr); + BUG_ON(htx->head_addr > htx->end_addr); + return (struct htx_ret){.ret = sz, .blk = tailblk}; + +rsv_new_block: + blk = htx_add_blk(htx, HTX_BLK_DATA, len); + if (!blk) + return (struct htx_ret){.ret = 0, .blk = NULL}; + blk->info += len; + return (struct htx_ret){.ret = 0, .blk = blk}; +} + +/* Adds an HTX block of type DATA in <htx>. It first tries to append data if + * possible. It returns the number of bytes consumed from <data>, which may be + * zero if nothing could be copied. + */ +size_t htx_add_data(struct htx *htx, const struct ist data) +{ + struct htx_blk *blk, *tailblk; + void *ptr; + uint32_t sz, room; + int32_t len = data.len; + + /* Not enough space to store data */ + if (len > htx_free_data_space(htx)) + len = htx_free_data_space(htx); + + if (!len) + return 0; + + if (htx->head == -1) + goto add_new_block; + + /* get the tail and head block */ + tailblk = htx_get_tail_blk(htx); + if (tailblk == NULL) + goto add_new_block; + sz = htx_get_blksz(tailblk); + + /* Don't try to append data if the last inserted block is not of the + * same type */ + if (htx_get_blk_type(tailblk) != HTX_BLK_DATA) + goto add_new_block; + + /* + * Same type and enough space: append data + */ + if (!htx->head_addr) { + if (tailblk->addr+sz != htx->tail_addr) + goto add_new_block; + room = (htx_pos_to_addr(htx, htx->tail) - htx->tail_addr); + } + else { + if (tailblk->addr+sz != htx->head_addr) + goto add_new_block; + room = (htx->end_addr - htx->head_addr); + } + BUG_ON((int32_t)room < 0); + if (room < len) + len = room; + + append_data: + /* Append data and update the block itself */ + ptr = htx_get_blk_ptr(htx, tailblk); + htx_memcpy(ptr + sz, data.ptr, len); + htx_change_blk_value_len(htx, tailblk, sz+len); + + BUG_ON((int32_t)htx->tail_addr < 0); + BUG_ON((int32_t)htx->head_addr < 0); + BUG_ON(htx->end_addr > htx->tail_addr); + BUG_ON(htx->head_addr > htx->end_addr); + return len; + + add_new_block: + blk = htx_add_blk(htx, HTX_BLK_DATA, len); + if (!blk) + return 0; + + blk->info += len; + htx_memcpy(htx_get_blk_ptr(htx, blk), data.ptr, len); + return len; +} + + +/* Adds an HTX block of type DATA in <htx> just after all other DATA + * blocks. Because it relies on htx_add_data_atonce(), It may be happened to a + * DATA block if possible. But, if the function succeeds, it will be the last + * DATA block in all cases. If an error occurred, NULL is returned. Otherwise, + * on success, the updated block (or the new one) is returned. + */ +struct htx_blk *htx_add_last_data(struct htx *htx, struct ist data) +{ + struct htx_blk *blk, *pblk; + + blk = htx_add_data_atonce(htx, data); + if (!blk) + return NULL; + + for (pblk = htx_get_prev_blk(htx, blk); pblk; pblk = htx_get_prev_blk(htx, pblk)) { + if (htx_get_blk_type(pblk) <= HTX_BLK_DATA) + break; + + /* Swap .addr and .info fields */ + blk->addr ^= pblk->addr; pblk->addr ^= blk->addr; blk->addr ^= pblk->addr; + blk->info ^= pblk->info; pblk->info ^= blk->info; blk->info ^= pblk->info; + + if (blk->addr == pblk->addr) + blk->addr += htx_get_blksz(pblk); + blk = pblk; + } + + return blk; +} + +/* Moves the block <blk> just before the block <ref>. Both blocks must be in the + * HTX message <htx> and <blk> must be placed after <ref>. pointer to these + * blocks are updated to remain valid after the move. */ +void htx_move_blk_before(struct htx *htx, struct htx_blk **blk, struct htx_blk **ref) +{ + struct htx_blk *cblk, *pblk; + + cblk = *blk; + for (pblk = htx_get_prev_blk(htx, cblk); pblk; pblk = htx_get_prev_blk(htx, pblk)) { + /* Swap .addr and .info fields */ + cblk->addr ^= pblk->addr; pblk->addr ^= cblk->addr; cblk->addr ^= pblk->addr; + cblk->info ^= pblk->info; pblk->info ^= cblk->info; cblk->info ^= pblk->info; + + if (cblk->addr == pblk->addr) + cblk->addr += htx_get_blksz(pblk); + if (pblk == *ref) + break; + cblk = pblk; + } + *blk = cblk; + *ref = pblk; +} + +/* Append the HTX message <src> to the HTX message <dst>. It returns 1 on + * success and 0 on error. All the message or nothing is copied. If an error + * occurred, all blocks from <src> already appended to <dst> are truncated. + */ +int htx_append_msg(struct htx *dst, const struct htx *src) +{ + struct htx_blk *blk, *newblk; + enum htx_blk_type type; + uint32_t blksz, offset = dst->data; + + for (blk = htx_get_head_blk(src); blk; blk = htx_get_next_blk(src, blk)) { + type = htx_get_blk_type(blk); + + if (type == HTX_BLK_UNUSED) + continue; + + blksz = htx_get_blksz(blk); + newblk = htx_add_blk(dst, type, blksz); + if (!newblk) + goto error; + newblk->info = blk->info; + htx_memcpy(htx_get_blk_ptr(dst, newblk), htx_get_blk_ptr(src, blk), blksz); + } + + return 1; + + error: + htx_truncate(dst, offset); + return 0; +} |