blob: 734058c5ce8bf4abe3065277cc3daa3c0ca73f9d [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 <common/buffer.h>
#include <common/debug.h>
#include <common/cfgparse.h>
#include <common/compat.h>
#include <common/config.h>
#include <common/errors.h>
#include <common/namespace.h>
#include <common/standard.h>
#include <common/hathreads.h>
#include <types/filters.h>
#include <types/proto_http.h>
#include <proto/compression.h>
#include <proto/filters.h>
#include <proto/flt_http_comp.h>
#include <proto/proto_http.h>
#include <proto/stream.h>
#include <proto/stream_interface.h>
/* Pool used to allocate filters */
struct pool_head *pool_head_filter = NULL;
static int handle_analyzer_result(struct stream *s, struct channel *chn, unsigned int an_bit, int ret);
/* - RESUME_FILTER_LOOP and RESUME_FILTER_END must always be used together.
* The first one begins a loop and the seconds one ends it.
*
* - BREAK_EXECUTION must be used to break the loop and set the filter from
* which to resume the next time.
*
* Here is an example:
*
* RESUME_FILTER_LOOP(stream, channel) {
* ...
* if (cond)
* BREAK_EXECUTION(stream, channel, label);
* ...
* } RESUME_FILTER_END;
* ...
* label:
* ...
*
*/
#define RESUME_FILTER_LOOP(strm, chn) \
do { \
struct filter *filter; \
\
if (strm_flt(strm)->current[CHN_IDX(chn)]) { \
filter = strm_flt(strm)->current[CHN_IDX(chn)]; \
strm_flt(strm)->current[CHN_IDX(chn)] = NULL; \
goto resume_execution; \
} \
\
list_for_each_entry(filter, &strm_flt(s)->filters, list) { \
resume_execution:
#define RESUME_FILTER_END \
} \
} while(0)
#define BREAK_EXECUTION(strm, chn, label) \
do { \
strm_flt(strm)->current[CHN_IDX(chn)] = filter; \
goto label; \
} while (0)
/* List head of all known filter keywords */
static struct flt_kw_list flt_keywords = {
.list = LIST_HEAD_INIT(flt_keywords.list)
};
/*
* Registers the filter keyword list <kwl> as a list of valid keywords for next
* parsing sessions.
*/
void
flt_register_keywords(struct flt_kw_list *kwl)
{
LIST_ADDQ(&flt_keywords.list, &kwl->list);
}
/*
* Returns a pointer to the filter keyword <kw>, or NULL if not found. If the
* keyword is found with a NULL ->parse() function, then an attempt is made to
* find one with a valid ->parse() function. This way it is possible to declare
* platform-dependant, known keywords as NULL, then only declare them as valid
* if some options are met. Note that if the requested keyword contains an
* opening parenthesis, everything from this point is ignored.
*/
struct flt_kw *
flt_find_kw(const char *kw)
{
int index;
const char *kwend;
struct flt_kw_list *kwl;
struct flt_kw *ret = NULL;
kwend = strchr(kw, '(');
if (!kwend)
kwend = kw + strlen(kw);
list_for_each_entry(kwl, &flt_keywords.list, list) {
for (index = 0; kwl->kw[index].kw != NULL; index++) {
if ((strncmp(kwl->kw[index].kw, kw, kwend - kw) == 0) &&
kwl->kw[index].kw[kwend-kw] == 0) {
if (kwl->kw[index].parse)
return &kwl->kw[index]; /* found it !*/
else
ret = &kwl->kw[index]; /* may be OK */
}
}
}
return ret;
}
/*
* Dumps all registered "filter" keywords to the <out> string pointer. The
* unsupported keywords are only dumped if their supported form was not found.
*/
void
flt_dump_kws(char **out)
{
struct flt_kw_list *kwl;
int index;
*out = NULL;
list_for_each_entry(kwl, &flt_keywords.list, list) {
for (index = 0; kwl->kw[index].kw != NULL; index++) {
if (kwl->kw[index].parse ||
flt_find_kw(kwl->kw[index].kw) == &kwl->kw[index]) {
memprintf(out, "%s[%4s] %s%s\n", *out ? *out : "",
kwl->scope,
kwl->kw[index].kw,
kwl->kw[index].parse ? "" : " (not supported)");
}
}
}
}
/*
* Lists the known filters on <out>
*/
void
list_filters(FILE *out)
{
char *filters, *p, *f;
fprintf(out, "Available filters :\n");
flt_dump_kws(&filters);
for (p = filters; (f = strtok_r(p,"\n",&p));)
fprintf(out, "\t%s\n", f);
free(filters);
}
/*
* Parses the "filter" keyword. All keywords must be handled by filters
* themselves
*/
static int
parse_filter(char **args, int section_type, struct proxy *curpx,
struct proxy *defpx, const char *file, int line, char **err)
{
struct flt_conf *fconf = NULL;
/* Filter cannot be defined on a default proxy */
if (curpx == defpx) {
memprintf(err, "parsing [%s:%d] : %s is not allowed in a 'default' section.",
file, line, args[0]);
return -1;
}
if (!strcmp(args[0], "filter")) {
struct flt_kw *kw;
int cur_arg;
if (!*args[1]) {
memprintf(err,
"parsing [%s:%d] : missing argument for '%s' in %s '%s'.",
file, line, args[0], proxy_type_str(curpx), curpx->id);
goto error;
}
fconf = calloc(1, sizeof(*fconf));
if (!fconf) {
memprintf(err, "'%s' : out of memory", args[0]);
goto error;
}
cur_arg = 1;
kw = flt_find_kw(args[cur_arg]);
if (kw) {
if (!kw->parse) {
memprintf(err, "parsing [%s:%d] : '%s' : "
"'%s' option is not implemented in this version (check build options).",
file, line, args[0], args[cur_arg]);
goto error;
}
if (kw->parse(args, &cur_arg, curpx, fconf, err, kw->private) != 0) {
if (err && *err)
memprintf(err, "'%s' : '%s'",
args[0], *err);
else
memprintf(err, "'%s' : error encountered while processing '%s'",
args[0], args[cur_arg]);
goto error;
}
}
else {
flt_dump_kws(err);
indent_msg(err, 4);
memprintf(err, "'%s' : unknown keyword '%s'.%s%s",
args[0], args[cur_arg],
err && *err ? " Registered keywords :" : "", err && *err ? *err : "");
goto error;
}
if (*args[cur_arg]) {
memprintf(err, "'%s %s' : unknown keyword '%s'.",
args[0], args[1], args[cur_arg]);
goto error;
}
if (fconf->ops == NULL) {
memprintf(err, "'%s %s' : no callbacks defined.",
args[0], args[1]);
goto error;
}
LIST_ADDQ(&curpx->filter_configs, &fconf->list);
}
return 0;
error:
free(fconf);
return -1;
}
/*
* Calls 'init' callback for all filters attached to a proxy. This happens after
* the configuration parsing. Filters can finish to fill their config. Returns
* (ERR_ALERT|ERR_FATAL) if an error occurs, 0 otherwise.
*/
static int
flt_init(struct proxy *proxy)
{
struct flt_conf *fconf;
list_for_each_entry(fconf, &proxy->filter_configs, list) {
if (fconf->ops->init && fconf->ops->init(proxy, fconf) < 0)
return ERR_ALERT|ERR_FATAL;
}
return 0;
}
/*
* Calls 'init_per_thread' callback for all filters attached to a proxy for each
* threads. This happens after the thread creation. Filters can finish to fill
* their config. Returns (ERR_ALERT|ERR_FATAL) if an error occurs, 0 otherwise.
*/
static int
flt_init_per_thread(struct proxy *proxy)
{
struct flt_conf *fconf;
list_for_each_entry(fconf, &proxy->filter_configs, list) {
if (fconf->ops->init_per_thread && fconf->ops->init_per_thread(proxy, fconf) < 0)
return ERR_ALERT|ERR_FATAL;
}
return 0;
}
/* Calls flt_init() for all proxies, see above */
static int
flt_init_all()
{
struct proxy *px;
int err_code = 0;
for (px = proxies_list; px; px = px->next) {
err_code |= flt_init(px);
if (err_code & (ERR_ABORT|ERR_FATAL)) {
ha_alert("Failed to initialize filters for proxy '%s'.\n",
px->id);
return err_code;
}
}
return 0;
}
/* Calls flt_init_per_thread() for all proxies, see above. Be carefull here, it
* returns 0 if an error occured. This is the opposite of flt_init_all. */
static int
flt_init_all_per_thread()
{
struct proxy *px;
int err_code = 0;
for (px = proxies_list; px; px = px->next) {
err_code = flt_init_per_thread(px);
if (err_code & (ERR_ABORT|ERR_FATAL)) {
ha_alert("Failed to initialize filters for proxy '%s' for thread %u.\n",
px->id, tid);
return 0;
}
}
return 1;
}
/*
* Calls 'check' callback for all filters attached to a proxy. This happens
* after the configuration parsing but before filters initialization. Returns
* the number of encountered errors.
*/
int
flt_check(struct proxy *proxy)
{
struct flt_conf *fconf;
int err = 0;
list_for_each_entry(fconf, &proxy->filter_configs, list) {
if (fconf->ops->check)
err += fconf->ops->check(proxy, fconf);
}
err += check_legacy_http_comp_flt(proxy);
return err;
}
/*
* Calls 'denit' callback for all filters attached to a proxy. This happens when
* HAProxy is stopped.
*/
void
flt_deinit(struct proxy *proxy)
{
struct flt_conf *fconf, *back;
list_for_each_entry_safe(fconf, back, &proxy->filter_configs, list) {
if (fconf->ops->deinit)
fconf->ops->deinit(proxy, fconf);
LIST_DEL(&fconf->list);
free(fconf);
}
}
/*
* Calls 'denit_per_thread' callback for all filters attached to a proxy for
* each threads. This happens before exiting a thread.
*/
void
flt_deinit_per_thread(struct proxy *proxy)
{
struct flt_conf *fconf, *back;
list_for_each_entry_safe(fconf, back, &proxy->filter_configs, list) {
if (fconf->ops->deinit_per_thread)
fconf->ops->deinit_per_thread(proxy, fconf);
}
}
/* Calls flt_deinit_per_thread() for all proxies, see above */
static void
flt_deinit_all_per_thread()
{
struct proxy *px;
for (px = proxies_list; px; px = px->next)
flt_deinit_per_thread(px);
}
/* Attaches a filter to a stream. Returns -1 if an error occurs, 0 otherwise. */
static int
flt_stream_add_filter(struct stream *s, struct flt_conf *fconf, unsigned int flags)
{
struct filter *f = pool_alloc(pool_head_filter);
if (!f) /* not enough memory */
return -1;
memset(f, 0, sizeof(*f));
f->config = fconf;
f->flags |= flags;
if (FLT_OPS(f)->attach) {
int ret = FLT_OPS(f)->attach(s, f);
if (ret <= 0) {
pool_free(pool_head_filter, f);
return ret;
}
}
LIST_ADDQ(&strm_flt(s)->filters, &f->list);
strm_flt(s)->flags |= STRM_FLT_FL_HAS_FILTERS;
return 0;
}
/*
* Called when a stream is created. It attaches all frontend filters to the
* stream. Returns -1 if an error occurs, 0 otherwise.
*/
int
flt_stream_init(struct stream *s)
{
struct flt_conf *fconf;
memset(strm_flt(s), 0, sizeof(*strm_flt(s)));
LIST_INIT(&strm_flt(s)->filters);
list_for_each_entry(fconf, &strm_fe(s)->filter_configs, list) {
if (flt_stream_add_filter(s, fconf, 0) < 0)
return -1;
}
return 0;
}
/*
* Called when a stream is closed or when analyze ends (For an HTTP stream, this
* happens after each request/response exchange). When analyze ends, backend
* filters are removed. When the stream is closed, all filters attached to the
* stream are removed.
*/
void
flt_stream_release(struct stream *s, int only_backend)
{
struct filter *filter, *back;
list_for_each_entry_safe(filter, back, &strm_flt(s)->filters, list) {
if (!only_backend || (filter->flags & FLT_FL_IS_BACKEND_FILTER)) {
if (FLT_OPS(filter)->detach)
FLT_OPS(filter)->detach(s, filter);
LIST_DEL(&filter->list);
pool_free(pool_head_filter, filter);
}
}
if (LIST_ISEMPTY(&strm_flt(s)->filters))
strm_flt(s)->flags &= ~STRM_FLT_FL_HAS_FILTERS;
}
/*
* Calls 'stream_start' for all filters attached to a stream. This happens when
* the stream is created, just after calling flt_stream_init
* function. Returns -1 if an error occurs, 0 otherwise.
*/
int
flt_stream_start(struct stream *s)
{
struct filter *filter;
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
if (FLT_OPS(filter)->stream_start && FLT_OPS(filter)->stream_start(s, filter) < 0)
return -1;
}
return 0;
}
/*
* Calls 'stream_stop' for all filters attached to a stream. This happens when
* the stream is stopped, just before calling flt_stream_release function.
*/
void
flt_stream_stop(struct stream *s)
{
struct filter *filter;
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
if (FLT_OPS(filter)->stream_stop)
FLT_OPS(filter)->stream_stop(s, filter);
}
}
/*
* Calls 'check_timeouts' for all filters attached to a stream. This happens when
* the stream is woken up because of expired timer.
*/
void
flt_stream_check_timeouts(struct stream *s)
{
struct filter *filter;
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
if (FLT_OPS(filter)->check_timeouts)
FLT_OPS(filter)->check_timeouts(s, filter);
}
}
/*
* Called when a backend is set for a stream. If the frontend and the backend
* are not the same, this function attaches all backend filters to the
* stream. Returns -1 if an error occurs, 0 otherwise.
*/
int
flt_set_stream_backend(struct stream *s, struct proxy *be)
{
struct flt_conf *fconf;
struct filter *filter;
if (strm_fe(s) == be)
goto end;
list_for_each_entry(fconf, &be->filter_configs, list) {
if (flt_stream_add_filter(s, fconf, FLT_FL_IS_BACKEND_FILTER) < 0)
return -1;
}
end:
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
if (FLT_OPS(filter)->stream_set_backend &&
FLT_OPS(filter)->stream_set_backend(s, filter, be) < 0)
return -1;
}
return 0;
}
/*
* Calls 'http_data' callback for all "data" filters attached to a stream. This
* function is called when incoming data are available (excluding chunks
* envelope for chunked messages) in the AN_REQ_HTTP_XFER_BODY and
* AN_RES_HTTP_XFER_BODY analyzers. It takes care to update the next offset of
* filters and adjusts available data to be sure that a filter cannot parse more
* data than its predecessors. A filter can choose to not consume all available
* data. Returns -1 if an error occurs, the number of consumed bytes otherwise.
*/
int
flt_http_data(struct stream *s, struct http_msg *msg)
{
struct filter *filter;
unsigned int buf_i;
int delta = 0, ret = 0;
/* Save buffer state */
buf_i = ci_data(msg->chn);
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
unsigned int *nxt;
/* Call "data" filters only */
if (!IS_DATA_FILTER(filter, msg->chn))
continue;
/* If the HTTP parser is ahead, we update the next offset of the
* current filter. This happens for chunked messages, at the
* begining of a new chunk. */
nxt = &FLT_NXT(filter, msg->chn);
if (msg->next > *nxt)
*nxt = msg->next;
if (FLT_OPS(filter)->http_data) {
unsigned int i = ci_data(msg->chn);
ret = FLT_OPS(filter)->http_data(s, filter, msg);
if (ret < 0)
break;
delta += (int)(ci_data(msg->chn) - i);
/* Update the next offset of the current filter */
*nxt += ret;
/* And set this value as the bound for the next
* filter. It will not able to parse more data than this
* one. */
b_set_data(&msg->chn->buf, co_data(msg->chn) + *nxt);
}
else {
/* Consume all available data and update the next offset
* of the current filter. buf->i is untouched here. */
ret = MIN(msg->chunk_len + msg->next, ci_data(msg->chn)) - *nxt;
*nxt += ret;
}
}
/* Restore the original buffer state */
b_set_data(&msg->chn->buf, co_data(msg->chn) + buf_i + delta);
return ret;
}
/*
* Calls 'http_chunk_trailers' callback for all "data" filters attached to a
* stream. This function is called for chunked messages only when a part of the
* trailers was parsed in the AN_REQ_HTTP_XFER_BODY and AN_RES_HTTP_XFER_BODY
* analyzers. Filters can know how much data were parsed by the HTTP parsing
* until the last call with the msg->sol value. Returns a negative value if an
* error occurs, any other value otherwise.
*/
int
flt_http_chunk_trailers(struct stream *s, struct http_msg *msg)
{
struct filter *filter;
int ret = 1;
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
unsigned int *nxt;
/* Call "data" filters only */
if (!IS_DATA_FILTER(filter, msg->chn))
continue;
/* Be sure to set the next offset of the filter at the right
* place. This is really useful when the first part of the
* trailers was parsed. */
nxt = &FLT_NXT(filter, msg->chn);
*nxt = msg->next;
if (FLT_OPS(filter)->http_chunk_trailers) {
ret = FLT_OPS(filter)->http_chunk_trailers(s, filter, msg);
if (ret < 0)
break;
}
/* Update the next offset of the current filter. Here all data
* are always consumed. */
*nxt += msg->sol;
}
return ret;
}
/*
* Calls 'http_end' callback for all filters attached to a stream. All filters
* are called here, but only if there is at least one "data" filter. This
* functions is called when all data were parsed and forwarded. 'http_end'
* callback is resumable, so this function returns a negative value if an error
* occurs, 0 if it needs to wait for some reason, any other value otherwise.
*/
int
flt_http_end(struct stream *s, struct http_msg *msg)
{
int ret = 1;
RESUME_FILTER_LOOP(s, msg->chn) {
if (FLT_OPS(filter)->http_end) {
ret = FLT_OPS(filter)->http_end(s, filter, msg);
if (ret <= 0)
BREAK_EXECUTION(s, msg->chn, end);
}
} RESUME_FILTER_END;
end:
return ret;
}
/*
* Calls 'http_reset' callback for all filters attached to a stream. This
* happens when a 100-continue response is received.
*/
void
flt_http_reset(struct stream *s, struct http_msg *msg)
{
struct filter *filter;
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
if (FLT_OPS(filter)->http_reset)
FLT_OPS(filter)->http_reset(s, filter, msg);
}
}
/*
* Calls 'http_reply' callback for all filters attached to a stream when HA
* decides to stop the HTTP message processing.
*/
void
flt_http_reply(struct stream *s, short status, const struct buffer *msg)
{
struct filter *filter;
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
if (FLT_OPS(filter)->http_reply)
FLT_OPS(filter)->http_reply(s, filter, status, msg);
}
}
/*
* Calls 'http_forward_data' callback for all "data" filters attached to a
* stream. This function is called when some data can be forwarded in the
* AN_REQ_HTTP_XFER_BODY and AN_RES_HTTP_XFER_BODY analyzers. It takes care to
* update the forward offset of filters and adjusts "forwardable" data to be
* sure that a filter cannot forward more data than its predecessors. A filter
* can choose to not forward all parsed data. Returns a negative value if an
* error occurs, else the number of forwarded bytes.
*/
int
flt_http_forward_data(struct stream *s, struct http_msg *msg, unsigned int len)
{
struct filter *filter;
int ret = len;
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
unsigned int *nxt, *fwd;
/* Call "data" filters only */
if (!IS_DATA_FILTER(filter, msg->chn))
continue;
/* If the HTTP parser is ahead, we update the next offset of the
* current filter. This happens for chunked messages, when the
* chunk envelope is parsed. */
nxt = &FLT_NXT(filter, msg->chn);
fwd = &FLT_FWD(filter, msg->chn);
if (msg->next > *nxt)
*nxt = msg->next;
if (FLT_OPS(filter)->http_forward_data) {
/* Remove bytes that the current filter considered as
* forwarded */
ret = FLT_OPS(filter)->http_forward_data(s, filter, msg, ret - *fwd);
if (ret < 0)
goto end;
}
/* Adjust bytes that the current filter considers as
* forwarded */
*fwd += ret;
/* And set this value as the bound for the next filter. It will
* not able to forward more data than the current one. */
ret = *fwd;
}
if (!ret)
goto end;
/* Finally, adjust filters offsets by removing data that HAProxy will
* forward. */
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
if (!IS_DATA_FILTER(filter, msg->chn))
continue;
FLT_NXT(filter, msg->chn) -= ret;
FLT_FWD(filter, msg->chn) -= ret;
}
end:
return ret;
}
/*
* Calls 'channel_start_analyze' callback for all filters attached to a
* stream. This function is called when we start to analyze a request or a
* response. For frontend filters, it is called before all other analyzers. For
* backend ones, it is called before all backend
* analyzers. 'channel_start_analyze' callback is resumable, so this function
* returns 0 if an error occurs or if it needs to wait, any other value
* otherwise.
*/
int
flt_start_analyze(struct stream *s, struct channel *chn, unsigned int an_bit)
{
int ret = 1;
/* If this function is called, this means there is at least one filter,
* so we do not need to check the filter list's emptiness. */
/* Set flag on channel to tell that the channel is filtered */
chn->flags |= CF_FLT_ANALYZE;
RESUME_FILTER_LOOP(s, chn) {
if (!(chn->flags & CF_ISRESP)) {
if (an_bit == AN_REQ_FLT_START_BE &&
!(filter->flags & FLT_FL_IS_BACKEND_FILTER))
continue;
}
else {
if (an_bit == AN_RES_FLT_START_BE &&
!(filter->flags & FLT_FL_IS_BACKEND_FILTER))
continue;
}
FLT_NXT(filter, chn) = 0;
FLT_FWD(filter, chn) = 0;
if (FLT_OPS(filter)->channel_start_analyze) {
ret = FLT_OPS(filter)->channel_start_analyze(s, filter, chn);
if (ret <= 0)
BREAK_EXECUTION(s, chn, end);
}
} RESUME_FILTER_END;
end:
return handle_analyzer_result(s, chn, an_bit, ret);
}
/*
* Calls 'channel_pre_analyze' callback for all filters attached to a
* stream. This function is called BEFORE each analyzer attached to a channel,
* expects analyzers responsible for data sending. 'channel_pre_analyze'
* callback is resumable, so this function returns 0 if an error occurs or if it
* needs to wait, any other value otherwise.
*
* Note this function can be called many times for the same analyzer. In fact,
* it is called until the analyzer finishes its processing.
*/
int
flt_pre_analyze(struct stream *s, struct channel *chn, unsigned int an_bit)
{
int ret = 1;
RESUME_FILTER_LOOP(s, chn) {
if (FLT_OPS(filter)->channel_pre_analyze && (filter->pre_analyzers & an_bit)) {
ret = FLT_OPS(filter)->channel_pre_analyze(s, filter, chn, an_bit);
if (ret <= 0)
BREAK_EXECUTION(s, chn, check_result);
}
} RESUME_FILTER_END;
check_result:
return handle_analyzer_result(s, chn, 0, ret);
}
/*
* Calls 'channel_post_analyze' callback for all filters attached to a
* stream. This function is called AFTER each analyzer attached to a channel,
* expects analyzers responsible for data sending. 'channel_post_analyze'
* callback is NOT resumable, so this function returns a 0 if an error occurs,
* any other value otherwise.
*
* Here, AFTER means when the analyzer finishes its processing.
*/
int
flt_post_analyze(struct stream *s, struct channel *chn, unsigned int an_bit)
{
struct filter *filter;
int ret = 1;
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
if (FLT_OPS(filter)->channel_post_analyze && (filter->post_analyzers & an_bit)) {
ret = FLT_OPS(filter)->channel_post_analyze(s, filter, chn, an_bit);
if (ret < 0)
break;
}
}
return handle_analyzer_result(s, chn, 0, ret);
}
/*
* This function is the AN_REQ/RES_FLT_HTTP_HDRS analyzer, used to filter HTTP
* headers or a request or a response. Returns 0 if an error occurs or if it
* needs to wait, any other value otherwise.
*/
int
flt_analyze_http_headers(struct stream *s, struct channel *chn, unsigned int an_bit)
{
struct filter *filter;
struct http_msg *msg;
int ret = 1;
msg = ((chn->flags & CF_ISRESP) ? &s->txn->rsp : &s->txn->req);
RESUME_FILTER_LOOP(s, chn) {
if (FLT_OPS(filter)->http_headers) {
ret = FLT_OPS(filter)->http_headers(s, filter, msg);
if (ret <= 0)
BREAK_EXECUTION(s, chn, check_result);
}
} RESUME_FILTER_END;
/* We increase next offset of all "data" filters after all processing on
* headers because any filter can alter them. So the definitive size of
* headers (msg->sov) is only known when all filters have been
* called. */
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
/* Handle "data" filters only */
if (!IS_DATA_FILTER(filter, chn))
continue;
FLT_NXT(filter, chn) = msg->sov;
}
check_result:
return handle_analyzer_result(s, chn, an_bit, ret);
}
/*
* Calls 'channel_end_analyze' callback for all filters attached to a
* stream. This function is called when we stop to analyze a request or a
* response. It is called after all other analyzers. 'channel_end_analyze'
* callback is resumable, so this function returns 0 if an error occurs or if it
* needs to wait, any other value otherwise.
*/
int
flt_end_analyze(struct stream *s, struct channel *chn, unsigned int an_bit)
{
int ret = 1;
/* Check if all filters attached on the stream have finished their
* processing on this channel. */
if (!(chn->flags & CF_FLT_ANALYZE))
goto sync;
RESUME_FILTER_LOOP(s, chn) {
FLT_NXT(filter, chn) = 0;
FLT_FWD(filter, chn) = 0;
unregister_data_filter(s, chn, filter);
if (FLT_OPS(filter)->channel_end_analyze) {
ret = FLT_OPS(filter)->channel_end_analyze(s, filter, chn);
if (ret <= 0)
BREAK_EXECUTION(s, chn, end);
}
} RESUME_FILTER_END;
end:
/* We don't remove yet this analyzer because we need to synchronize the
* both channels. So here, we just remove the flag CF_FLT_ANALYZE. */
ret = handle_analyzer_result(s, chn, 0, ret);
if (ret) {
chn->flags &= ~CF_FLT_ANALYZE;
/* Pretend there is an activity on both channels. Flag on the
* current one will be automatically removed, so only the other
* one will remain. This is a way to be sure that
* 'channel_end_analyze' callback will have a chance to be
* called at least once for the other side to finish the current
* processing. Of course, this is the filter responsiblity to
* wakeup the stream if it choose to loop on this callback. */
s->req.flags |= CF_WAKE_ONCE;
s->res.flags |= CF_WAKE_ONCE;
}
sync:
/* Now we can check if filters have finished their work on the both
* channels */
if (!(s->req.flags & CF_FLT_ANALYZE) && !(s->res.flags & CF_FLT_ANALYZE)) {
/* Sync channels by removing this analyzer for the both channels */
s->req.analysers &= ~AN_REQ_FLT_END;
s->res.analysers &= ~AN_RES_FLT_END;
/* Clean up the HTTP transaction if needed */
if (s->txn && (s->txn->flags & TX_WAIT_CLEANUP))
http_end_txn_clean_session(s);
/* Remove backend filters from the list */
flt_stream_release(s, 1);
}
return ret;
}
/*
* Calls 'tcp_data' callback for all "data" filters attached to a stream. This
* function is called when incoming data are available. It takes care to update
* the next offset of filters and adjusts available data to be sure that a
* filter cannot parse more data than its predecessors. A filter can choose to
* not consume all available data. Returns -1 if an error occurs, the number of
* consumed bytes otherwise.
*/
static int
flt_data(struct stream *s, struct channel *chn)
{
struct filter *filter;
unsigned int buf_i;
int delta = 0, ret = 0;
/* Save buffer state */
buf_i = ci_data(chn);
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
unsigned int *nxt;
/* Call "data" filters only */
if (!IS_DATA_FILTER(filter, chn))
continue;
nxt = &FLT_NXT(filter, chn);
if (FLT_OPS(filter)->tcp_data) {
unsigned int i = ci_data(chn);
ret = FLT_OPS(filter)->tcp_data(s, filter, chn);
if (ret < 0)
break;
delta += (int)(ci_data(chn) - i);
/* Increase next offset of the current filter */
*nxt += ret;
/* And set this value as the bound for the next
* filter. It will not able to parse more data than the
* current one. */
b_set_data(&chn->buf, co_data(chn) + *nxt);
}
else {
/* Consume all available data */
*nxt = ci_data(chn);
}
/* Update <ret> value to be sure to have the last one when we
* exit from the loop. This value will be used to know how much
* data are "forwardable" */
ret = *nxt;
}
/* Restore the original buffer state */
b_set_data(&chn->buf, co_data(chn) + buf_i + delta);
return ret;
}
/*
* Calls 'tcp_forward_data' callback for all "data" filters attached to a
* stream. This function is called when some data can be forwarded. It takes
* care to update the forward offset of filters and adjusts "forwardable" data
* to be sure that a filter cannot forward more data than its predecessors. A
* filter can choose to not forward all parsed data. Returns a negative value if
* an error occurs, else the number of forwarded bytes.
*/
static int
flt_forward_data(struct stream *s, struct channel *chn, unsigned int len)
{
struct filter *filter;
int ret = len;
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
unsigned int *fwd;
/* Call "data" filters only */
if (!IS_DATA_FILTER(filter, chn))
continue;
fwd = &FLT_FWD(filter, chn);
if (FLT_OPS(filter)->tcp_forward_data) {
/* Remove bytes that the current filter considered as
* forwarded */
ret = FLT_OPS(filter)->tcp_forward_data(s, filter, chn, ret - *fwd);
if (ret < 0)
goto end;
}
/* Adjust bytes that the current filter considers as
* forwarded */
*fwd += ret;
/* And set this value as the bound for the next filter. It will
* not able to forward more data than the current one. */
ret = *fwd;
}
if (!ret)
goto end;
/* Finally, adjust filters offsets by removing data that HAProxy will
* forward. */
list_for_each_entry(filter, &strm_flt(s)->filters, list) {
if (!IS_DATA_FILTER(filter, chn))
continue;
FLT_NXT(filter, chn) -= ret;
FLT_FWD(filter, chn) -= ret;
}
end:
return ret;
}
/*
* Called when TCP data must be filtered on a channel. This function is the
* AN_REQ/RES_FLT_XFER_DATA analyzer. When called, it is responsible to forward
* data when the proxy is not in http mode. Behind the scene, it calls
* consecutively 'tcp_data' and 'tcp_forward_data' callbacks for all "data"
* filters attached to a stream. Returns 0 if an error occurs or if it needs to
* wait, any other value otherwise.
*/
int
flt_xfer_data(struct stream *s, struct channel *chn, unsigned int an_bit)
{
int ret = 1;
/* If there is no "data" filters, we do nothing */
if (!HAS_DATA_FILTERS(s, chn))
goto end;
/* Be sure that the output is still opened. Else we stop the data
* filtering. */
if ((chn->flags & (CF_READ_ERROR|CF_READ_TIMEOUT|CF_WRITE_ERROR|CF_WRITE_TIMEOUT)) ||
((chn->flags & CF_SHUTW) && (chn->to_forward || co_data(chn))))
goto end;
/* Let all "data" filters parsing incoming data */
ret = flt_data(s, chn);
if (ret < 0)
goto end;
/* And forward them */
ret = flt_forward_data(s, chn, ret);
if (ret < 0)
goto end;
/* Consume data that all filters consider as forwarded. */
c_adv(chn, ret);
/* Stop waiting data if the input in closed and no data is pending or if
* the output is closed. */
if ((chn->flags & CF_SHUTW) ||
((chn->flags & CF_SHUTR) && !ci_data(chn))) {
ret = 1;
goto end;
}
/* Wait for data */
return 0;
end:
/* Terminate the data filtering. If <ret> is negative, an error was
* encountered during the filtering. */
return handle_analyzer_result(s, chn, an_bit, ret);
}
/*
* Handles result of filter's analyzers. It returns 0 if an error occurs or if
* it needs to wait, any other value otherwise.
*/
static int
handle_analyzer_result(struct stream *s, struct channel *chn,
unsigned int an_bit, int ret)
{
int finst;
if (ret < 0)
goto return_bad_req;
else if (!ret)
goto wait;
/* End of job, return OK */
if (an_bit) {
chn->analysers &= ~an_bit;
chn->analyse_exp = TICK_ETERNITY;
}
return 1;
return_bad_req:
/* An error occurs */
channel_abort(&s->req);
channel_abort(&s->res);
if (!(chn->flags & CF_ISRESP)) {
s->req.analysers &= AN_REQ_FLT_END;
finst = SF_FINST_R;
/* FIXME: incr counters */
}
else {
s->res.analysers &= AN_RES_FLT_END;
finst = SF_FINST_H;
/* FIXME: incr counters */
}
if (s->txn) {
/* Do not do that when we are waiting for the next request */
if (s->txn->status)
http_reply_and_close(s, s->txn->status, NULL);
else {
s->txn->status = 400;
http_reply_and_close(s, 400, http_error_message(s));
}
}
if (!(s->flags & SF_ERR_MASK))
s->flags |= SF_ERR_PRXCOND;
if (!(s->flags & SF_FINST_MASK))
s->flags |= finst;
return 0;
wait:
if (!(chn->flags & CF_ISRESP))
channel_dont_connect(chn);
return 0;
}
/* Note: must not be declared <const> as its list will be overwritten.
* Please take care of keeping this list alphabetically sorted, doing so helps
* all code contributors.
* Optional keywords are also declared with a NULL ->parse() function so that
* the config parser can report an appropriate error when a known keyword was
* not enabled. */
static struct cfg_kw_list cfg_kws = {ILH, {
{ CFG_LISTEN, "filter", parse_filter },
{ 0, NULL, NULL },
}
};
__attribute__((constructor))
static void
__filters_init(void)
{
pool_head_filter = create_pool("filter", sizeof(struct filter), MEM_F_SHARED);
cfg_register_keywords(&cfg_kws);
hap_register_post_check(flt_init_all);
hap_register_per_thread_init(flt_init_all_per_thread);
hap_register_per_thread_deinit(flt_deinit_all_per_thread);
}
__attribute__((destructor))
static void
__filters_deinit(void)
{
pool_destroy(pool_head_filter);
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/