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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/acl.h>
#include <proto/compression.h>
#include <proto/freq_ctr.h>
#include <proto/proto_http.h>
#ifdef USE_ZLIB
static void *alloc_zlib(void *opaque, unsigned int items, unsigned int size);
static void free_zlib(void *opaque, void *ptr);
/* 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;
long zlib_used_memory = 0;
#endif
unsigned int compress_min_idle = 0;
static struct pool_head *pool_comp_ctx = NULL;
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)
{
int left;
/* not enough space */
if (in->size - buffer_len(in) < 40)
return -1;
/* We start by copying the current buffer's pending outgoing data into
* a new temporary buffer that we initialize with a new empty chunk.
*/
b_reset(out);
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 consumed_data = 0;
int data_process_len;
int block1, block2;
/*
* Temporarily skip already parsed data and chunks to jump to the
* actual data block. It is fixed before leaving.
*/
b_adv(in, msg->next);
/*
* select the smallest size between the announced chunk size, the input
* data, and the available output buffer size. The compressors are
* assumed to be able to process all the bytes we pass to them at once.
*/
data_process_len = MIN(in->i, msg->chunk_len);
data_process_len = MIN(out->size - buffer_len(out), data_process_len);
block1 = data_process_len;
if (block1 > bi_contig_data(in))
block1 = bi_contig_data(in);
block2 = data_process_len - block1;
/* compressors return < 0 upon error or the amount of bytes read */
consumed_data = s->comp_algo->add_data(s->comp_ctx, bi_ptr(in), block1, out);
if (consumed_data >= 0 && block2 > 0) {
consumed_data = s->comp_algo->add_data(s->comp_ctx, in->data, block2, out);
if (consumed_data >= 0)
consumed_data += block1;
}
/* restore original buffer pointer */
b_rew(in, msg->next);
if (consumed_data > 0) {
msg->next += consumed_data;
msg->chunk_len -= consumed_data;
}
return consumed_data;
}
/*
* 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';
/* At the end of data, we must write the empty chunk 0<CRLF>,
* and terminate the trailers section with a last <CRLF>. If
* we're forwarding a chunked-encoded response, we'll have a
* trailers section after the empty chunk which needs to be
* forwarded and which will provide the last CRLF. Otherwise
* we write it ourselves.
*/
if (msg->msg_state >= HTTP_MSG_TRAILERS) {
memcpy(tail, "0\r\n", 3);
tail += 3;
if (msg->msg_state >= HTTP_MSG_DONE) {
memcpy(tail, "\r\n", 2);
tail += 2;
}
}
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 && s->comp_ctx->cur_lvl > 0) {
update_freq_ctr(&global.comp_bps_in, msg->next);
s->fe->fe_counters.comp_in += msg->next;
s->be->be_counters.comp_in += msg->next;
} else {
s->fe->fe_counters.comp_byp += msg->next;
s->be->be_counters.comp_byp += msg->next;
}
/* copy the remaining data in the tmp buffer. */
b_adv(ib, msg->next);
msg->next = 0;
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 && s->comp_ctx->cur_lvl > 0) {
update_freq_ctr(&global.comp_bps_out, to_forward);
s->fe->fe_counters.comp_out += to_forward;
s->be->be_counters.comp_out += to_forward;
}
/* forward the new chunk without remaining data */
b_adv(ob, to_forward);
return to_forward;
}
/*
* Alloc the comp_ctx
*/
static inline int init_comp_ctx(struct comp_ctx **comp_ctx)
{
#ifdef USE_ZLIB
z_stream *strm;
if (global.maxzlibmem > 0 && (global.maxzlibmem - zlib_used_memory) < sizeof(struct comp_ctx))
return -1;
#endif
if (unlikely(pool_comp_ctx == NULL))
pool_comp_ctx = create_pool("comp_ctx", sizeof(struct comp_ctx), MEM_F_SHARED);
*comp_ctx = pool_alloc2(pool_comp_ctx);
if (*comp_ctx == NULL)
return -1;
#ifdef USE_ZLIB
zlib_used_memory += sizeof(struct comp_ctx);
strm = &(*comp_ctx)->strm;
strm->zalloc = alloc_zlib;
strm->zfree = free_zlib;
strm->opaque = *comp_ctx;
#endif
return 0;
}
/*
* Dealloc the comp_ctx
*/
static inline int deinit_comp_ctx(struct comp_ctx **comp_ctx)
{
if (!*comp_ctx)
return 0;
pool_free2(pool_comp_ctx, *comp_ctx);
*comp_ctx = NULL;
#ifdef USE_ZLIB
zlib_used_memory -= sizeof(struct comp_ctx);
#endif
return 0;
}
/****************************
**** Identity algorithm ****
****************************/
/*
* Init the identity algorithm
*/
int identity_init(struct comp_ctx **comp_ctx, int level)
{
return 0;
}
/*
* Process data
* Return size of consumed data or -1 on error
*/
int identity_add_data(struct comp_ctx *comp_ctx, const char *in_data, int in_len, struct buffer *out)
{
char *out_data = bi_end(out);
int out_len = out->size - buffer_len(out);
if (out_len < in_len)
return -1;
memcpy(out_data, in_data, in_len);
out->i += 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;
struct pool_head *pool = NULL;
if (global.maxzlibmem > 0 && (global.maxzlibmem - zlib_used_memory) < (long)(items * size))
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);
pool = zlib_pool_deflate_state;
ctx->zlib_deflate_state = buf = pool_alloc2(pool);
break;
case 1:
if (zlib_pool_window == NULL)
zlib_pool_window = create_pool("zlib_window", size * items, MEM_F_SHARED);
pool = zlib_pool_window;
ctx->zlib_window = buf = pool_alloc2(pool);
break;
case 2:
if (zlib_pool_prev == NULL)
zlib_pool_prev = create_pool("zlib_prev", size * items, MEM_F_SHARED);
pool = zlib_pool_prev;
ctx->zlib_prev = buf = pool_alloc2(pool);
break;
case 3:
if (zlib_pool_head == NULL)
zlib_pool_head = create_pool("zlib_head", size * items, MEM_F_SHARED);
pool = zlib_pool_head;
ctx->zlib_head = buf = pool_alloc2(pool);
break;
case 4:
if (zlib_pool_pending_buf == NULL)
zlib_pool_pending_buf = create_pool("zlib_pending_buf", size * items, MEM_F_SHARED);
pool = zlib_pool_pending_buf;
ctx->zlib_pending_buf = buf = pool_alloc2(pool);
break;
}
if (buf != NULL)
zlib_used_memory += pool->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);
zlib_used_memory -= pool->size;
}
/**************************
**** gzip algorithm ****
***************************/
int gzip_init(struct comp_ctx **comp_ctx, int level)
{
z_stream *strm;
if (init_comp_ctx(comp_ctx) < 0)
return -1;
strm = &(*comp_ctx)->strm;
if (deflateInit2(strm, level, Z_DEFLATED, global.tune.zlibwindowsize + 16, global.tune.zlibmemlevel, Z_DEFAULT_STRATEGY) != Z_OK) {
deinit_comp_ctx(comp_ctx);
return -1;
}
(*comp_ctx)->cur_lvl = level;
return 0;
}
/**************************
**** Deflate algorithm ****
***************************/
int deflate_init(struct comp_ctx **comp_ctx, int level)
{
z_stream *strm;
if (init_comp_ctx(comp_ctx) < 0)
return -1;
strm = &(*comp_ctx)->strm;
if (deflateInit2(strm, level, Z_DEFLATED, global.tune.zlibwindowsize, global.tune.zlibmemlevel, Z_DEFAULT_STRATEGY) != Z_OK) {
deinit_comp_ctx(comp_ctx);
return -1;
}
(*comp_ctx)->cur_lvl = level;
return 0;
}
/* Return the size of consumed data or -1 */
int deflate_add_data(struct comp_ctx *comp_ctx, const char *in_data, int in_len, struct buffer *out)
{
int ret;
z_stream *strm = &comp_ctx->strm;
char *out_data = bi_end(out);
int out_len = out->size - buffer_len(out);
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 */
out->i += out_len - strm->avail_out;
return in_len - strm->avail_in;
}
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 limit */
if ((global.comp_rate_lim > 0 && (read_freq_ctr(&global.comp_bps_out) > global.comp_rate_lim)) || /* rate */
(idle_pct < compress_min_idle)) { /* idle */
/* 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.tune.comp_maxlevel) {
/* 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;
int ret;
ret = deflateEnd(strm);
deinit_comp_ctx(comp_ctx);
return ret;
}
#endif /* USE_ZLIB */
/* boolean, returns true if compression is used (either gzip or deflate) in the response */
static int
smp_fetch_res_comp(struct proxy *px, struct session *l4, void *l7, unsigned int opt,
const struct arg *args, struct sample *smp, const char *kw)
{
smp->type = SMP_T_BOOL;
smp->data.uint = (l4->comp_algo != NULL);
return 1;
}
/* string, returns algo */
static int
smp_fetch_res_comp_algo(struct proxy *px, struct session *l4, void *l7, unsigned int opt,
const struct arg *args, struct sample *smp, const char *kw)
{
if (!l4->comp_algo)
return 0;
smp->type = SMP_T_STR;
smp->flags = SMP_F_CONST;
smp->data.str.str = l4->comp_algo->name;
smp->data.str.len = l4->comp_algo->name_len;
return 1;
}
/* Note: must not be declared <const> as its list will be overwritten */
static struct acl_kw_list acl_kws = {ILH, {
{ /* END */ },
}};
/* Note: must not be declared <const> as its list will be overwritten */
static struct sample_fetch_kw_list sample_fetch_keywords = {ILH, {
{ "res.comp", smp_fetch_res_comp, 0, NULL, SMP_T_BOOL, SMP_USE_HRSHP },
{ "res.comp_algo", smp_fetch_res_comp_algo, 0, NULL, SMP_T_STR, SMP_USE_HRSHP },
{ /* END */ },
}};
__attribute__((constructor))
static void __comp_fetch_init(void)
{
acl_register_keywords(&acl_kws);
sample_register_fetches(&sample_fetch_keywords);
}