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/*
* HTTP compression.
*
* Copyright 2012 Exceliance, David Du Colombier <dducolombier@exceliance.fr>
* William Lallemand <wlallemand@exceliance.fr>
*
* 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 <stdio.h>
#ifdef USE_ZLIB
/* Note: the crappy zlib and openssl libs both define the "free_func" type.
* That's a very clever idea to use such a generic name in general purpose
* libraries, really... The zlib one is easier to redefine than openssl's,
* so let's only fix this one.
*/
#define free_func zlib_free_func
#include <zlib.h>
#undef free_func
#endif /* USE_ZLIB */
#include <common/compat.h>
#include <common/memory.h>
#include <types/global.h>
#include <types/compression.h>
#include <proto/compression.h>
#include <proto/freq_ctr.h>
#include <proto/proto_http.h>
#ifdef USE_ZLIB
/* zlib allocation */
static struct pool_head *zlib_pool_deflate_state = NULL;
static struct pool_head *zlib_pool_window = NULL;
static struct pool_head *zlib_pool_prev = NULL;
static struct pool_head *zlib_pool_head = NULL;
static struct pool_head *zlib_pool_pending_buf = NULL;
static long long zlib_memory_available = -1;
#endif
const struct comp_algo comp_algos[] =
{
{ "identity", 8, identity_init, identity_add_data, identity_flush, identity_reset, identity_end },
#ifdef USE_ZLIB
{ "deflate", 7, deflate_init, deflate_add_data, deflate_flush, deflate_reset, deflate_end },
{ "gzip", 4, gzip_init, deflate_add_data, deflate_flush, deflate_reset, deflate_end },
#endif /* USE_ZLIB */
{ NULL, 0, NULL , NULL, NULL, NULL, NULL }
};
/*
* Add a content-type in the configuration
*/
int comp_append_type(struct comp *comp, const char *type)
{
struct comp_type *comp_type;
comp_type = calloc(1, sizeof(struct comp_type));
comp_type->name_len = strlen(type);
comp_type->name = strdup(type);
comp_type->next = comp->types;
comp->types = comp_type;
return 0;
}
/*
* Add an algorithm in the configuration
*/
int comp_append_algo(struct comp *comp, const char *algo)
{
struct comp_algo *comp_algo;
int i;
for (i = 0; comp_algos[i].name; i++) {
if (!strcmp(algo, comp_algos[i].name)) {
comp_algo = calloc(1, sizeof(struct comp_algo));
memmove(comp_algo, &comp_algos[i], sizeof(struct comp_algo));
comp_algo->next = comp->algos;
comp->algos = comp_algo;
return 0;
}
}
return -1;
}
/* emit the chunksize followed by a CRLF on the output and return the number of
* bytes written. Appends <add_crlf> additional CRLF after the first one. Chunk
* sizes are truncated to 6 hex digits (16 MB) and padded left. The caller is
* responsible for ensuring there is enough room left in the output buffer for
* the string (8 bytes * add_crlf*2).
*/
int http_emit_chunk_size(char *out, unsigned int chksz, int add_crlf)
{
int shift;
int pos = 0;
for (shift = 20; shift >= 0; shift -= 4)
out[pos++] = hextab[(chksz >> shift) & 0xF];
do {
out[pos++] = '\r';
out[pos++] = '\n';
} while (--add_crlf >= 0);
return pos;
}
/*
* Init HTTP compression
*/
int http_compression_buffer_init(struct session *s, struct buffer *in, struct buffer *out)
{
struct http_msg *msg = &s->txn.rsp;
int left;
/* not enough space */
if (in->size - buffer_len(in) < 40)
return -1;
/*
* Skip data, we don't need them in the new buffer. They are results
* of CHUNK_CRLF and CHUNK_SIZE parsing.
*/
b_adv(in, msg->next);
msg->next = 0;
msg->sov = 0;
msg->sol = 0;
out->size = global.tune.bufsize;
out->i = 0;
out->o = 0;
out->p = out->data;
/* copy output data */
if (in->o > 0) {
left = in->o - bo_contig_data(in);
memcpy(out->data, bo_ptr(in), bo_contig_data(in));
out->p += bo_contig_data(in);
if (left > 0) { /* second part of the buffer */
memcpy(out->p, in->data, left);
out->p += left;
}
out->o = in->o;
}
out->i += http_emit_chunk_size(out->p, 0, 0);
return 0;
}
/*
* Add data to compress
*/
int http_compression_buffer_add_data(struct session *s, struct buffer *in, struct buffer *out)
{
struct http_msg *msg = &s->txn.rsp;
int data_process_len;
int left;
int ret;
/*
* Skip data, we don't need them in the new buffer. They are results
* of CHUNK_CRLF and CHUNK_SIZE parsing.
*/
b_adv(in, msg->next);
msg->next = 0;
msg->sov = 0;
msg->sol = 0;
/*
* select the smallest size between the announced chunk size, the input
* data, and the available output buffer size
*/
data_process_len = MIN(in->i, msg->chunk_len);
data_process_len = MIN(out->size - buffer_len(out), data_process_len);
left = data_process_len - bi_contig_data(in);
if (left <= 0) {
ret = s->comp_algo->add_data(&s->comp_ctx, bi_ptr(in),
data_process_len, bi_end(out),
out->size - buffer_len(out));
if (ret < 0)
return -1;
out->i += ret;
} else {
ret = s->comp_algo->add_data(&s->comp_ctx, bi_ptr(in), bi_contig_data(in), bi_end(out), out->size - buffer_len(out));
if (ret < 0)
return -1;
out->i += ret;
ret = s->comp_algo->add_data(&s->comp_ctx, in->data, left, bi_end(out), out->size - buffer_len(out));
if (ret < 0)
return -1;
out->i += ret;
}
b_adv(in, data_process_len);
msg->chunk_len -= data_process_len;
return 0;
}
/*
* Flush data in process, and write the header and footer of the chunk. Upon
* success, in and out buffers are swapped to avoid a copy.
*/
int http_compression_buffer_end(struct session *s, struct buffer **in, struct buffer **out, int end)
{
int to_forward;
int left;
struct http_msg *msg = &s->txn.rsp;
struct buffer *ib = *in, *ob = *out;
#ifdef USE_ZLIB
int ret;
/* flush data here */
if (end)
ret = s->comp_algo->flush(&s->comp_ctx, ob, Z_FINISH); /* end of data */
else
ret = s->comp_algo->flush(&s->comp_ctx, ob, Z_SYNC_FLUSH); /* end of buffer */
if (ret < 0)
return -1; /* flush failed */
#endif /* USE_ZLIB */
if (ob->i > 8) {
/* more than a chunk size => some data were emitted */
char *tail = ob->p + ob->i;
/* write real size at the begining of the chunk, no need of wrapping */
http_emit_chunk_size(ob->p, ob->i - 8, 0);
/* chunked encoding requires CRLF after data */
*tail++ = '\r';
*tail++ = '\n';
if (!(msg->flags & HTTP_MSGF_TE_CHNK) && msg->chunk_len == 0) {
/* End of data, 0<CRLF><CRLF> is needed but we're not
* in chunked mode on input so we must add it ourselves.
*/
memcpy(tail, "0\r\n\r\n", 5);
tail += 5;
}
ob->i = tail - ob->p;
} else {
/* no data were sent, cancel the chunk size */
ob->i = 0;
}
to_forward = ob->i;
/* update input rate */
if (s->comp_ctx.cur_lvl > 0)
update_freq_ctr(&global.comp_bps_in, ib->o - ob->o);
/* copy the remaining data in the tmp buffer. */
if (ib->i > 0) {
left = ib->i - bi_contig_data(ib);
memcpy(bi_end(ob), bi_ptr(ib), bi_contig_data(ib));
ob->i += bi_contig_data(ib);
if (left > 0) {
memcpy(bi_end(ob), ib->data, left);
ob->i += left;
}
}
/* swap the buffers */
*in = ob;
*out = ib;
if (s->comp_ctx.cur_lvl > 0)
update_freq_ctr(&global.comp_bps_out, to_forward);
/* forward the new chunk without remaining data */
b_adv(ob, to_forward);
/* if there are data between p and next, there are trailers, must forward them */
b_adv(ob, msg->next);
msg->next = 0;
return to_forward;
}
/****************************
**** Identity algorithm ****
****************************/
/*
* Init the identity algorithm
*/
int identity_init(struct comp_ctx *comp_ctx, int level)
{
return 0;
}
/*
* Process data
* Return size of processed data or -1 on error
*/
int identity_add_data(struct comp_ctx *comp_ctx, const char *in_data, int in_len, char *out_data, int out_len)
{
if (out_len < in_len)
return -1;
memcpy(out_data, in_data, in_len);
return in_len;
}
int identity_flush(struct comp_ctx *comp_ctx, struct buffer *out, int flag)
{
return 0;
}
int identity_reset(struct comp_ctx *comp_ctx)
{
return 0;
}
/*
* Deinit the algorithm
*/
int identity_end(struct comp_ctx *comp_ctx)
{
return 0;
}
#ifdef USE_ZLIB
/*
* This is a tricky allocation function using the zlib.
* This is based on the allocation order in deflateInit2.
*/
static void *alloc_zlib(void *opaque, unsigned int items, unsigned int size)
{
struct comp_ctx *ctx = opaque;
static char round = 0; /* order in deflateInit2 */
void *buf = NULL;
if (global.maxzlibmem > 0 && zlib_memory_available < items * size){
buf = NULL;
goto end;
}
switch (round) {
case 0:
if (zlib_pool_deflate_state == NULL)
zlib_pool_deflate_state = create_pool("zlib_state", size * items, MEM_F_SHARED);
ctx->zlib_deflate_state = buf = pool_alloc2(zlib_pool_deflate_state);
break;
case 1:
if (zlib_pool_window == NULL)
zlib_pool_window = create_pool("zlib_window", size * items, MEM_F_SHARED);
ctx->zlib_window = buf = pool_alloc2(zlib_pool_window);
break;
case 2:
if (zlib_pool_prev == NULL)
zlib_pool_prev = create_pool("zlib_prev", size * items, MEM_F_SHARED);
ctx->zlib_prev = buf = pool_alloc2(zlib_pool_prev);
break;
case 3:
if (zlib_pool_head == NULL)
zlib_pool_head = create_pool("zlib_head", size * items, MEM_F_SHARED);
ctx->zlib_head = buf = pool_alloc2(zlib_pool_head);
break;
case 4:
if (zlib_pool_pending_buf == NULL)
zlib_pool_pending_buf = create_pool("zlib_pending_buf", size * items, MEM_F_SHARED);
ctx->zlib_pending_buf = buf = pool_alloc2(zlib_pool_pending_buf);
break;
}
if (buf != NULL && global.maxzlibmem > 0)
zlib_memory_available -= items * size;
end:
/* deflateInit2() first allocates and checks the deflate_state, then if
* it succeeds, it allocates all other 4 areas at ones and checks them
* at the end. So we want to correctly count the rounds depending on when
* zlib is supposed to abort.
*/
if (buf || round)
round = (round + 1) % 5;
return buf;
}
static void free_zlib(void *opaque, void *ptr)
{
struct comp_ctx *ctx = opaque;
struct pool_head *pool = NULL;
if (ptr == ctx->zlib_window)
pool = zlib_pool_window;
else if (ptr == ctx->zlib_deflate_state)
pool = zlib_pool_deflate_state;
else if (ptr == ctx->zlib_prev)
pool = zlib_pool_prev;
else if (ptr == ctx->zlib_head)
pool = zlib_pool_head;
else if (ptr == ctx->zlib_pending_buf)
pool = zlib_pool_pending_buf;
pool_free2(pool, ptr);
if (global.maxzlibmem > 0)
zlib_memory_available += pool->size;
}
/**************************
**** gzip algorithm ****
***************************/
int gzip_init(struct comp_ctx *comp_ctx, int level)
{
z_stream *strm = &comp_ctx->strm;
if (global.maxzlibmem > 0 && zlib_memory_available < 0)
zlib_memory_available = global.maxzlibmem * 1024 * 1024; /* Megabytes to bytes */
strm->zalloc = alloc_zlib;
strm->zfree = free_zlib;
strm->opaque = comp_ctx;
if (deflateInit2(&comp_ctx->strm, level, Z_DEFLATED, global.tune.zlibwindowsize + 16, global.tune.zlibmemlevel, Z_DEFAULT_STRATEGY) != Z_OK)
return -1;
return 0;
}
/**************************
**** Deflate algorithm ****
***************************/
int deflate_init(struct comp_ctx *comp_ctx, int level)
{
z_stream *strm = &comp_ctx->strm;
strm->zalloc = alloc_zlib;
strm->zfree = free_zlib;
strm->opaque = comp_ctx;
if (deflateInit(&comp_ctx->strm, level) != Z_OK)
return -1;
return 0;
}
int deflate_add_data(struct comp_ctx *comp_ctx, const char *in_data, int in_len, char *out_data, int out_len)
{
z_stream *strm = &comp_ctx->strm;
int ret;
if (in_len <= 0)
return 0;
if (out_len <= 0)
return -1;
strm->next_in = (unsigned char *)in_data;
strm->avail_in = in_len;
strm->next_out = (unsigned char *)out_data;
strm->avail_out = out_len;
ret = deflate(strm, Z_NO_FLUSH);
if (ret != Z_OK)
return -1;
/* deflate update the available data out */
return out_len - strm->avail_out;
}
int deflate_flush(struct comp_ctx *comp_ctx, struct buffer *out, int flag)
{
int ret;
int out_len = 0;
z_stream *strm = &comp_ctx->strm;
strm->next_out = (unsigned char *)bi_end(out);
strm->avail_out = out->size - buffer_len(out);
ret = deflate(strm, flag);
if (ret != Z_OK && ret != Z_STREAM_END)
return -1;
out_len = (out->size - buffer_len(out)) - strm->avail_out;
out->i += out_len;
/* compression rate limit */
if (global.comp_rate_lim > 0) {
if (read_freq_ctr(&global.comp_bps_out) > global.comp_rate_lim) {
/* decrease level */
if (comp_ctx->cur_lvl > 0) {
comp_ctx->cur_lvl--;
deflateParams(&comp_ctx->strm, comp_ctx->cur_lvl, Z_DEFAULT_STRATEGY);
}
} else if (comp_ctx->cur_lvl < global.comp_rate_lim) {
/* increase level */
comp_ctx->cur_lvl++ ;
deflateParams(&comp_ctx->strm, comp_ctx->cur_lvl, Z_DEFAULT_STRATEGY);
}
}
return out_len;
}
int deflate_reset(struct comp_ctx *comp_ctx)
{
z_stream *strm = &comp_ctx->strm;
if (deflateReset(strm) == Z_OK)
return 0;
return -1;
}
int deflate_end(struct comp_ctx *comp_ctx)
{
z_stream *strm = &comp_ctx->strm;
if (deflateEnd(strm) != Z_OK)
return -1;
return 0;
}
#endif /* USE_ZLIB */