blob: c8eeba244ade3adf49c9878361eb2603cf5c20e5 [file] [log] [blame]
/*
* Stream filters related variables and functions.
*
* Copyright (C) 2015 Qualys Inc., Christopher Faulet <cfaulet@qualys.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/api.h>
#include <haproxy/cfgparse.h>
#include <haproxy/compression.h>
#include <haproxy/dynbuf.h>
#include <haproxy/filters.h>
#include <haproxy/http.h>
#include <haproxy/http_ana-t.h>
#include <haproxy/http_htx.h>
#include <haproxy/htx.h>
#include <haproxy/list.h>
#include <haproxy/proxy-t.h>
#include <haproxy/sample.h>
#include <haproxy/stream.h>
#include <haproxy/tools.h>
const char *http_comp_flt_id = "compression filter";
struct flt_ops comp_ops;
struct comp_state {
struct comp_ctx *comp_ctx; /* compression context */
struct comp_algo *comp_algo; /* compression algorithm if not NULL */
};
/* Pools used to allocate comp_state structs */
DECLARE_STATIC_POOL(pool_head_comp_state, "comp_state", sizeof(struct comp_state));
static THREAD_LOCAL struct buffer tmpbuf;
static THREAD_LOCAL struct buffer zbuf;
static int select_compression_request_header(struct comp_state *st,
struct stream *s,
struct http_msg *msg);
static int select_compression_response_header(struct comp_state *st,
struct stream *s,
struct http_msg *msg);
static int set_compression_response_header(struct comp_state *st,
struct stream *s,
struct http_msg *msg);
static int htx_compression_buffer_init(struct htx *htx, struct buffer *out);
static int htx_compression_buffer_add_data(struct comp_state *st, const char *data, size_t len,
struct buffer *out);
static int htx_compression_buffer_end(struct comp_state *st, struct buffer *out, int end);
/***********************************************************************/
static int
comp_flt_init(struct proxy *px, struct flt_conf *fconf)
{
fconf->flags |= FLT_CFG_FL_HTX;
return 0;
}
static int
comp_flt_init_per_thread(struct proxy *px, struct flt_conf *fconf)
{
if (!tmpbuf.size && b_alloc(&tmpbuf) == NULL)
return -1;
if (!zbuf.size && b_alloc(&zbuf) == NULL)
return -1;
return 0;
}
static void
comp_flt_deinit_per_thread(struct proxy *px, struct flt_conf *fconf)
{
if (tmpbuf.size)
b_free(&tmpbuf);
if (zbuf.size)
b_free(&zbuf);
}
static int
comp_strm_init(struct stream *s, struct filter *filter)
{
struct comp_state *st;
st = pool_alloc_dirty(pool_head_comp_state);
if (st == NULL)
return -1;
st->comp_algo = NULL;
st->comp_ctx = NULL;
filter->ctx = st;
/* Register post-analyzer on AN_RES_WAIT_HTTP because we need to
* analyze response headers before http-response rules execution
* to be sure we can use res.comp and res.comp_algo sample
* fetches */
filter->post_analyzers |= AN_RES_WAIT_HTTP;
return 1;
}
static void
comp_strm_deinit(struct stream *s, struct filter *filter)
{
struct comp_state *st = filter->ctx;
if (!st)
return;
/* release any possible compression context */
if (st->comp_algo)
st->comp_algo->end(&st->comp_ctx);
pool_free(pool_head_comp_state, st);
filter->ctx = NULL;
}
static int
comp_http_headers(struct stream *s, struct filter *filter, struct http_msg *msg)
{
struct comp_state *st = filter->ctx;
if (!strm_fe(s)->comp && !s->be->comp)
goto end;
if (!(msg->chn->flags & CF_ISRESP))
select_compression_request_header(st, s, msg);
else {
/* Response headers have already been checked in
* comp_http_post_analyze callback. */
if (st->comp_algo) {
if (!set_compression_response_header(st, s, msg))
goto end;
register_data_filter(s, msg->chn, filter);
}
}
end:
return 1;
}
static int
comp_http_post_analyze(struct stream *s, struct filter *filter,
struct channel *chn, unsigned an_bit)
{
struct http_txn *txn = s->txn;
struct http_msg *msg = &txn->rsp;
struct comp_state *st = filter->ctx;
if (an_bit != AN_RES_WAIT_HTTP)
goto end;
if (!strm_fe(s)->comp && !s->be->comp)
goto end;
select_compression_response_header(st, s, msg);
end:
return 1;
}
static int
comp_http_payload(struct stream *s, struct filter *filter, struct http_msg *msg,
unsigned int offset, unsigned int len)
{
struct comp_state *st = filter->ctx;
struct htx *htx = htxbuf(&msg->chn->buf);
struct htx_ret htxret = htx_find_offset(htx, offset);
struct htx_blk *blk;
int ret, consumed = 0, to_forward = 0;
blk = htxret.blk;
offset = htxret.ret;
for (; blk && len; blk = htx_get_next_blk(htx, blk)) {
enum htx_blk_type type = htx_get_blk_type(blk);
uint32_t sz = htx_get_blksz(blk);
struct ist v;
switch (type) {
case HTX_BLK_UNUSED:
break;
case HTX_BLK_DATA:
v = htx_get_blk_value(htx, blk);
v.ptr += offset;
v.len -= offset;
if (v.len > len)
v.len = len;
if (htx_compression_buffer_init(htx, &trash) < 0) {
msg->chn->flags |= CF_WAKE_WRITE;
goto end;
}
ret = htx_compression_buffer_add_data(st, v.ptr, v.len, &trash);
if (ret < 0)
goto error;
if (htx_compression_buffer_end(st, &trash, 0) < 0)
goto error;
len -= ret;
consumed += ret;
to_forward += b_data(&trash);
if (ret == sz && !b_data(&trash)) {
offset = 0;
blk = htx_remove_blk(htx, blk);
continue;
}
v.len = ret;
blk = htx_replace_blk_value(htx, blk, v, ist2(b_head(&trash), b_data(&trash)));
break;
case HTX_BLK_TLR:
case HTX_BLK_EOT:
case HTX_BLK_EOM:
if (msg->flags & HTTP_MSGF_COMPRESSING) {
if (htx_compression_buffer_init(htx, &trash) < 0) {
msg->chn->flags |= CF_WAKE_WRITE;
goto end;
}
if (htx_compression_buffer_end(st, &trash, 1) < 0)
goto error;
if (b_data(&trash)) {
struct htx_blk *last = htx_add_last_data(htx, ist2(b_head(&trash), b_data(&trash)));
if (!last)
goto error;
blk = htx_get_next_blk(htx, last);
if (!blk)
goto error;
to_forward += b_data(&trash);
}
msg->flags &= ~HTTP_MSGF_COMPRESSING;
/* We let the mux add last empty chunk and empty trailers */
}
/* fall through */
default:
sz -= offset;
if (sz > len)
sz = len;
consumed += sz;
to_forward += sz;
len -= sz;
break;
}
offset = 0;
}
end:
if (to_forward != consumed)
flt_update_offsets(filter, msg->chn, to_forward - consumed);
if (st->comp_ctx && st->comp_ctx->cur_lvl > 0) {
update_freq_ctr(&global.comp_bps_in, consumed);
_HA_ATOMIC_ADD(&strm_fe(s)->fe_counters.comp_in, consumed);
_HA_ATOMIC_ADD(&s->be->be_counters.comp_in, consumed);
update_freq_ctr(&global.comp_bps_out, to_forward);
_HA_ATOMIC_ADD(&strm_fe(s)->fe_counters.comp_out, to_forward);
_HA_ATOMIC_ADD(&s->be->be_counters.comp_out, to_forward);
} else {
_HA_ATOMIC_ADD(&strm_fe(s)->fe_counters.comp_byp, consumed);
_HA_ATOMIC_ADD(&s->be->be_counters.comp_byp, consumed);
}
return to_forward;
error:
return -1;
}
static int
comp_http_end(struct stream *s, struct filter *filter,
struct http_msg *msg)
{
struct comp_state *st = filter->ctx;
if (!(msg->chn->flags & CF_ISRESP) || !st || !st->comp_algo)
goto end;
if (strm_fe(s)->mode == PR_MODE_HTTP)
_HA_ATOMIC_ADD(&strm_fe(s)->fe_counters.p.http.comp_rsp, 1);
if ((s->flags & SF_BE_ASSIGNED) && (s->be->mode == PR_MODE_HTTP))
_HA_ATOMIC_ADD(&s->be->be_counters.p.http.comp_rsp, 1);
end:
return 1;
}
/***********************************************************************/
static int
set_compression_response_header(struct comp_state *st, struct stream *s, struct http_msg *msg)
{
struct htx *htx = htxbuf(&msg->chn->buf);
struct http_hdr_ctx ctx;
/*
* Add Content-Encoding header when it's not identity encoding.
* RFC 2616 : Identity encoding: This content-coding is used only in the
* Accept-Encoding header, and SHOULD NOT be used in the Content-Encoding
* header.
*/
if (st->comp_algo->cfg_name_len != 8 || memcmp(st->comp_algo->cfg_name, "identity", 8) != 0) {
struct ist v = ist2(st->comp_algo->ua_name, st->comp_algo->ua_name_len);
if (!http_add_header(htx, ist("Content-Encoding"), v))
goto error;
}
/* remove Content-Length header */
if (msg->flags & HTTP_MSGF_CNT_LEN) {
ctx.blk = NULL;
while (http_find_header(htx, ist("Content-Length"), &ctx, 1))
http_remove_header(htx, &ctx);
}
/* add "Transfer-Encoding: chunked" header */
if (!(msg->flags & HTTP_MSGF_TE_CHNK)) {
if (!http_add_header(htx, ist("Transfer-Encoding"), ist("chunked")))
goto error;
}
/* convert "ETag" header to a weak ETag */
ctx.blk = NULL;
if (http_find_header(htx, ist("ETag"), &ctx, 1)) {
if (ctx.value.ptr[0] == '"') {
/* This a strong ETag. Convert it to a weak one. */
struct ist v = ist2(trash.area, 0);
if (istcat(&v, ist("W/"), trash.size) == -1 || istcat(&v, ctx.value, trash.size) == -1)
goto error;
if (!http_replace_header_value(htx, &ctx, v))
goto error;
}
}
if (!http_add_header(htx, ist("Vary"), ist("Accept-Encoding")))
goto error;
return 1;
error:
st->comp_algo->end(&st->comp_ctx);
st->comp_algo = NULL;
return 0;
}
/*
* Selects a compression algorithm depending on the client request.
*/
static int
select_compression_request_header(struct comp_state *st, struct stream *s, struct http_msg *msg)
{
struct htx *htx = htxbuf(&msg->chn->buf);
struct http_hdr_ctx ctx;
struct comp_algo *comp_algo = NULL;
struct comp_algo *comp_algo_back = NULL;
/* Disable compression for older user agents announcing themselves as "Mozilla/4"
* unless they are known good (MSIE 6 with XP SP2, or MSIE 7 and later).
* See http://zoompf.com/2012/02/lose-the-wait-http-compression for more details.
*/
ctx.blk = NULL;
if (http_find_header(htx, ist("User-Agent"), &ctx, 1) &&
ctx.value.len >= 9 &&
memcmp(ctx.value.ptr, "Mozilla/4", 9) == 0 &&
(ctx.value.len < 31 ||
memcmp(ctx.value.ptr + 25, "MSIE ", 5) != 0 ||
*(ctx.value.ptr + 30) < '6' ||
(*(ctx.value.ptr + 30) == '6' &&
(ctx.value.len < 54 || memcmp(ctx.value.ptr + 51, "SV1", 3) != 0)))) {
st->comp_algo = NULL;
return 0;
}
/* search for the algo in the backend in priority or the frontend */
if ((s->be->comp && (comp_algo_back = s->be->comp->algos)) ||
(strm_fe(s)->comp && (comp_algo_back = strm_fe(s)->comp->algos))) {
int best_q = 0;
ctx.blk = NULL;
while (http_find_header(htx, ist("Accept-Encoding"), &ctx, 0)) {
const char *qval;
int q;
int toklen;
/* try to isolate the token from the optional q-value */
toklen = 0;
while (toklen < ctx.value.len && HTTP_IS_TOKEN(*(ctx.value.ptr + toklen)))
toklen++;
qval = ctx.value.ptr + toklen;
while (1) {
while (qval < ctx.value.ptr + ctx.value.len && HTTP_IS_LWS(*qval))
qval++;
if (qval >= ctx.value.ptr + ctx.value.len || *qval != ';') {
qval = NULL;
break;
}
qval++;
while (qval < ctx.value.ptr + ctx.value.len && HTTP_IS_LWS(*qval))
qval++;
if (qval >= ctx.value.ptr + ctx.value.len) {
qval = NULL;
break;
}
if (strncmp(qval, "q=", MIN(ctx.value.ptr + ctx.value.len - qval, 2)) == 0)
break;
while (qval < ctx.value.ptr + ctx.value.len && *qval != ';')
qval++;
}
/* here we have qval pointing to the first "q=" attribute or NULL if not found */
q = qval ? http_parse_qvalue(qval + 2, NULL) : 1000;
if (q <= best_q)
continue;
for (comp_algo = comp_algo_back; comp_algo; comp_algo = comp_algo->next) {
if (*(ctx.value.ptr) == '*' ||
word_match(ctx.value.ptr, toklen, comp_algo->ua_name, comp_algo->ua_name_len)) {
st->comp_algo = comp_algo;
best_q = q;
break;
}
}
}
}
/* remove all occurrences of the header when "compression offload" is set */
if (st->comp_algo) {
if ((s->be->comp && s->be->comp->offload) ||
(strm_fe(s)->comp && strm_fe(s)->comp->offload)) {
http_remove_header(htx, &ctx);
ctx.blk = NULL;
while (http_find_header(htx, ist("Accept-Encoding"), &ctx, 1))
http_remove_header(htx, &ctx);
}
return 1;
}
/* identity is implicit does not require headers */
if ((s->be->comp && (comp_algo_back = s->be->comp->algos)) ||
(strm_fe(s)->comp && (comp_algo_back = strm_fe(s)->comp->algos))) {
for (comp_algo = comp_algo_back; comp_algo; comp_algo = comp_algo->next) {
if (comp_algo->cfg_name_len == 8 && memcmp(comp_algo->cfg_name, "identity", 8) == 0) {
st->comp_algo = comp_algo;
return 1;
}
}
}
st->comp_algo = NULL;
return 0;
}
/*
* Selects a compression algorithm depending of the server response.
*/
static int
select_compression_response_header(struct comp_state *st, struct stream *s, struct http_msg *msg)
{
struct htx *htx = htxbuf(&msg->chn->buf);
struct http_txn *txn = s->txn;
struct http_hdr_ctx ctx;
struct comp_type *comp_type;
/* no common compression algorithm was found in request header */
if (st->comp_algo == NULL)
goto fail;
/* compression already in progress */
if (msg->flags & HTTP_MSGF_COMPRESSING)
goto fail;
/* HTTP < 1.1 should not be compressed */
if (!(msg->flags & HTTP_MSGF_VER_11) || !(txn->req.flags & HTTP_MSGF_VER_11))
goto fail;
if (txn->meth == HTTP_METH_HEAD)
goto fail;
/* compress 200,201,202,203 responses only */
if ((txn->status != 200) &&
(txn->status != 201) &&
(txn->status != 202) &&
(txn->status != 203))
goto fail;
if (!(msg->flags & HTTP_MSGF_XFER_LEN) || msg->flags & HTTP_MSGF_BODYLESS)
goto fail;
/* content is already compressed */
ctx.blk = NULL;
if (http_find_header(htx, ist("Content-Encoding"), &ctx, 1))
goto fail;
/* no compression when Cache-Control: no-transform is present in the message */
ctx.blk = NULL;
while (http_find_header(htx, ist("Cache-Control"), &ctx, 0)) {
if (word_match(ctx.value.ptr, ctx.value.len, "no-transform", 12))
goto fail;
}
/* no compression when ETag is malformed */
ctx.blk = NULL;
if (http_find_header(htx, ist("ETag"), &ctx, 1)) {
if (http_get_etag_type(ctx.value) == ETAG_INVALID)
goto fail;
}
/* no compression when multiple ETags are present
* Note: Do not reset ctx.blk!
*/
if (http_find_header(htx, ist("ETag"), &ctx, 1))
goto fail;
comp_type = NULL;
/* we don't want to compress multipart content-types, nor content-types that are
* not listed in the "compression type" directive if any. If no content-type was
* found but configuration requires one, we don't compress either. Backend has
* the priority.
*/
ctx.blk = NULL;
if (http_find_header(htx, ist("Content-Type"), &ctx, 1)) {
if (ctx.value.len >= 9 && strncasecmp("multipart", ctx.value.ptr, 9) == 0)
goto fail;
if ((s->be->comp && (comp_type = s->be->comp->types)) ||
(strm_fe(s)->comp && (comp_type = strm_fe(s)->comp->types))) {
for (; comp_type; comp_type = comp_type->next) {
if (ctx.value.len >= comp_type->name_len &&
strncasecmp(ctx.value.ptr, comp_type->name, comp_type->name_len) == 0)
/* this Content-Type should be compressed */
break;
}
/* this Content-Type should not be compressed */
if (comp_type == NULL)
goto fail;
}
}
else { /* no content-type header */
if ((s->be->comp && s->be->comp->types) ||
(strm_fe(s)->comp && strm_fe(s)->comp->types))
goto fail; /* a content-type was required */
}
/* limit compression rate */
if (global.comp_rate_lim > 0)
if (read_freq_ctr(&global.comp_bps_in) > global.comp_rate_lim)
goto fail;
/* limit cpu usage */
if (ti->idle_pct < compress_min_idle)
goto fail;
/* initialize compression */
if (st->comp_algo->init(&st->comp_ctx, global.tune.comp_maxlevel) < 0)
goto fail;
msg->flags |= HTTP_MSGF_COMPRESSING;
return 1;
fail:
st->comp_algo = NULL;
return 0;
}
/***********************************************************************/
static int
htx_compression_buffer_init(struct htx *htx, struct buffer *out)
{
/* output stream requires at least 10 bytes for the gzip header, plus
* at least 8 bytes for the gzip trailer (crc+len), plus a possible
* plus at most 5 bytes per 32kB block and 2 bytes to close the stream.
*/
if (htx_free_space(htx) < 20 + 5 * ((htx->data + 32767) >> 15))
return -1;
b_reset(out);
return 0;
}
static int
htx_compression_buffer_add_data(struct comp_state *st, const char *data, size_t len,
struct buffer *out)
{
return st->comp_algo->add_data(st->comp_ctx, data, len, out);
}
static int
htx_compression_buffer_end(struct comp_state *st, struct buffer *out, int end)
{
if (end)
return st->comp_algo->finish(st->comp_ctx, out);
else
return st->comp_algo->flush(st->comp_ctx, out);
}
/***********************************************************************/
struct flt_ops comp_ops = {
.init = comp_flt_init,
.init_per_thread = comp_flt_init_per_thread,
.deinit_per_thread = comp_flt_deinit_per_thread,
.attach = comp_strm_init,
.detach = comp_strm_deinit,
.channel_post_analyze = comp_http_post_analyze,
.http_headers = comp_http_headers,
.http_payload = comp_http_payload,
.http_end = comp_http_end,
};
static int
parse_compression_options(char **args, int section, struct proxy *proxy,
struct proxy *defpx, const char *file, int line,
char **err)
{
struct comp *comp;
if (proxy->comp == NULL) {
comp = calloc(1, sizeof(*comp));
proxy->comp = comp;
}
else
comp = proxy->comp;
if (strcmp(args[1], "algo") == 0) {
struct comp_ctx *ctx;
int cur_arg = 2;
if (!*args[cur_arg]) {
memprintf(err, "parsing [%s:%d] : '%s' expects <algorithm>\n",
file, line, args[0]);
return -1;
}
while (*(args[cur_arg])) {
if (comp_append_algo(comp, args[cur_arg]) < 0) {
memprintf(err, "'%s' : '%s' is not a supported algorithm.\n",
args[0], args[cur_arg]);
return -1;
}
if (proxy->comp->algos->init(&ctx, 9) == 0)
proxy->comp->algos->end(&ctx);
else {
memprintf(err, "'%s' : Can't init '%s' algorithm.\n",
args[0], args[cur_arg]);
return -1;
}
cur_arg++;
continue;
}
}
else if (strcmp(args[1], "offload") == 0)
comp->offload = 1;
else if (strcmp(args[1], "type") == 0) {
int cur_arg = 2;
if (!*args[cur_arg]) {
memprintf(err, "'%s' expects <type>\n", args[0]);
return -1;
}
while (*(args[cur_arg])) {
comp_append_type(comp, args[cur_arg]);
cur_arg++;
continue;
}
}
else {
memprintf(err, "'%s' expects 'algo', 'type' or 'offload'\n",
args[0]);
return -1;
}
return 0;
}
static int
parse_http_comp_flt(char **args, int *cur_arg, struct proxy *px,
struct flt_conf *fconf, char **err, void *private)
{
struct flt_conf *fc, *back;
list_for_each_entry_safe(fc, back, &px->filter_configs, list) {
if (fc->id == http_comp_flt_id) {
memprintf(err, "%s: Proxy supports only one compression filter\n", px->id);
return -1;
}
}
fconf->id = http_comp_flt_id;
fconf->conf = NULL;
fconf->ops = &comp_ops;
(*cur_arg)++;
return 0;
}
int
check_implicit_http_comp_flt(struct proxy *proxy)
{
struct flt_conf *fconf;
int explicit = 0;
int comp = 0;
int err = 0;
if (proxy->comp == NULL)
goto end;
if (!LIST_ISEMPTY(&proxy->filter_configs)) {
list_for_each_entry(fconf, &proxy->filter_configs, list) {
if (fconf->id == http_comp_flt_id)
comp = 1;
else if (fconf->id == cache_store_flt_id) {
if (comp) {
ha_alert("config: %s '%s': unable to enable the compression filter "
"before any cache filter.\n",
proxy_type_str(proxy), proxy->id);
err++;
goto end;
}
}
else if (fconf->id == fcgi_flt_id)
continue;
else
explicit = 1;
}
}
if (comp)
goto end;
else if (explicit) {
ha_alert("config: %s '%s': require an explicit filter declaration to use "
"HTTP compression\n", proxy_type_str(proxy), proxy->id);
err++;
goto end;
}
/* Implicit declaration of the compression filter is always the last
* one */
fconf = calloc(1, sizeof(*fconf));
if (!fconf) {
ha_alert("config: %s '%s': out of memory\n",
proxy_type_str(proxy), proxy->id);
err++;
goto end;
}
fconf->id = http_comp_flt_id;
fconf->conf = NULL;
fconf->ops = &comp_ops;
LIST_ADDQ(&proxy->filter_configs, &fconf->list);
end:
return err;
}
/*
* boolean, returns true if compression is used (either gzip or deflate) in the
* response.
*/
static int
smp_fetch_res_comp(const struct arg *args, struct sample *smp, const char *kw,
void *private)
{
struct http_txn *txn = smp->strm ? smp->strm->txn : NULL;
smp->data.type = SMP_T_BOOL;
smp->data.u.sint = (txn && (txn->rsp.flags & HTTP_MSGF_COMPRESSING));
return 1;
}
/*
* string, returns algo
*/
static int
smp_fetch_res_comp_algo(const struct arg *args, struct sample *smp,
const char *kw, void *private)
{
struct http_txn *txn = smp->strm ? smp->strm->txn : NULL;
struct filter *filter;
struct comp_state *st;
if (!txn || !(txn->rsp.flags & HTTP_MSGF_COMPRESSING))
return 0;
list_for_each_entry(filter, &strm_flt(smp->strm)->filters, list) {
if (FLT_ID(filter) != http_comp_flt_id)
continue;
if (!(st = filter->ctx))
break;
smp->data.type = SMP_T_STR;
smp->flags = SMP_F_CONST;
smp->data.u.str.area = st->comp_algo->cfg_name;
smp->data.u.str.data = st->comp_algo->cfg_name_len;
return 1;
}
return 0;
}
/* Declare the config parser for "compression" keyword */
static struct cfg_kw_list cfg_kws = {ILH, {
{ CFG_LISTEN, "compression", parse_compression_options },
{ 0, NULL, NULL },
}
};
INITCALL1(STG_REGISTER, cfg_register_keywords, &cfg_kws);
/* Declare the filter parser for "compression" keyword */
static struct flt_kw_list filter_kws = { "COMP", { }, {
{ "compression", parse_http_comp_flt, NULL },
{ NULL, NULL, NULL },
}
};
INITCALL1(STG_REGISTER, flt_register_keywords, &filter_kws);
/* 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 */ },
}
};
INITCALL1(STG_REGISTER, sample_register_fetches, &sample_fetch_keywords);