blob: 0ebd78a38e38069088e509acab3af5e39d469c24 [file] [log] [blame]
/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "httpd.h"
#include "http_config.h"
#include "http_request.h"
#include "http_connection.h"
#include "http_protocol.h"
#include "http_log.h"
#include "http_core.h"
#include "util_filter.h"
#define APR_WANT_STRFUNC
#include "apr_strings.h"
#include "apr_version.h"
module AP_MODULE_DECLARE_DATA reqtimeout_module;
#define UNSET -1
#define MRT_DEFAULT_handshake_TIMEOUT 0 /* disabled */
#define MRT_DEFAULT_handshake_MAX_TIMEOUT 0
#define MRT_DEFAULT_handshake_MIN_RATE 0
#define MRT_DEFAULT_header_TIMEOUT 20
#define MRT_DEFAULT_header_MAX_TIMEOUT 40
#define MRT_DEFAULT_header_MIN_RATE 500
#define MRT_DEFAULT_body_TIMEOUT 20
#define MRT_DEFAULT_body_MAX_TIMEOUT 0
#define MRT_DEFAULT_body_MIN_RATE 500
typedef struct
{
int timeout; /* timeout in secs */
int max_timeout; /* max timeout in secs */
int min_rate; /* min rate in bytes/s */
apr_time_t rate_factor; /* scale factor (#usecs per min_rate) */
} reqtimeout_stage_t;
typedef struct
{
reqtimeout_stage_t handshake; /* Handshaking (TLS) */
reqtimeout_stage_t header; /* Reading the HTTP header */
reqtimeout_stage_t body; /* Reading the HTTP body */
} reqtimeout_srv_cfg;
/* this struct is used both as conn_config and as filter context */
typedef struct
{
apr_time_t timeout_at;
apr_time_t max_timeout_at;
reqtimeout_stage_t cur_stage;
int in_keep_alive;
char *type;
apr_socket_t *socket;
apr_bucket_brigade *tmpbb;
} reqtimeout_con_cfg;
static const char *const reqtimeout_filter_name = "reqtimeout";
static int default_handshake_rate_factor;
static int default_header_rate_factor;
static int default_body_rate_factor;
static void extend_timeout(reqtimeout_con_cfg *ccfg, apr_bucket_brigade *bb)
{
apr_off_t len;
apr_time_t new_timeout_at;
if (apr_brigade_length(bb, 0, &len) != APR_SUCCESS || len <= 0)
return;
new_timeout_at = ccfg->timeout_at + len * ccfg->cur_stage.rate_factor;
if (ccfg->max_timeout_at > 0 && new_timeout_at > ccfg->max_timeout_at) {
ccfg->timeout_at = ccfg->max_timeout_at;
}
else {
ccfg->timeout_at = new_timeout_at;
}
}
static apr_status_t check_time_left(reqtimeout_con_cfg *ccfg,
apr_time_t *time_left_p,
apr_time_t now)
{
if (!now)
now = apr_time_now();
*time_left_p = ccfg->timeout_at - now;
if (*time_left_p <= 0)
return APR_TIMEUP;
if (*time_left_p < apr_time_from_sec(1)) {
*time_left_p = apr_time_from_sec(1);
}
return APR_SUCCESS;
}
static apr_status_t have_lf_or_eos(apr_bucket_brigade *bb)
{
apr_bucket *b = APR_BRIGADE_LAST(bb);
for ( ; b != APR_BRIGADE_SENTINEL(bb) ; b = APR_BUCKET_PREV(b) ) {
const char *str;
apr_size_t len;
apr_status_t rv;
if (APR_BUCKET_IS_EOS(b))
return APR_SUCCESS;
if (APR_BUCKET_IS_METADATA(b))
continue;
rv = apr_bucket_read(b, &str, &len, APR_BLOCK_READ);
if (rv != APR_SUCCESS)
return rv;
if (len == 0)
continue;
if (str[len-1] == APR_ASCII_LF)
return APR_SUCCESS;
}
return APR_INCOMPLETE;
}
/*
* Append bbIn to bbOut and merge small buckets, to avoid DoS by high memory
* usage
*/
static apr_status_t brigade_append(apr_bucket_brigade *bbOut, apr_bucket_brigade *bbIn)
{
while (!APR_BRIGADE_EMPTY(bbIn)) {
apr_bucket *e = APR_BRIGADE_FIRST(bbIn);
const char *str;
apr_size_t len;
apr_status_t rv;
rv = apr_bucket_read(e, &str, &len, APR_BLOCK_READ);
if (rv != APR_SUCCESS) {
return rv;
}
APR_BUCKET_REMOVE(e);
if (APR_BUCKET_IS_METADATA(e) || len > APR_BUCKET_BUFF_SIZE/4) {
APR_BRIGADE_INSERT_TAIL(bbOut, e);
}
else {
if (len > 0) {
rv = apr_brigade_write(bbOut, NULL, NULL, str, len);
if (rv != APR_SUCCESS) {
apr_bucket_destroy(e);
return rv;
}
}
apr_bucket_destroy(e);
}
}
return APR_SUCCESS;
}
#define MIN(x,y) ((x) < (y) ? (x) : (y))
static apr_status_t reqtimeout_filter(ap_filter_t *f,
apr_bucket_brigade *bb,
ap_input_mode_t mode,
apr_read_type_e block,
apr_off_t readbytes)
{
apr_time_t time_left;
apr_time_t now = 0;
apr_status_t rv;
apr_interval_time_t saved_sock_timeout = UNSET;
reqtimeout_con_cfg *ccfg = f->ctx;
if (ccfg->in_keep_alive) {
/* For this read[_request line()], wait for the first byte using the
* normal keep-alive timeout (hence don't take this expected idle time
* into account to setup the connection expiry below).
*/
ccfg->in_keep_alive = 0;
rv = ap_get_brigade(f->next, bb, AP_MODE_SPECULATIVE, block, 1);
if (rv != APR_SUCCESS || APR_BRIGADE_EMPTY(bb)) {
return rv;
}
apr_brigade_cleanup(bb);
}
if (ccfg->cur_stage.timeout > 0) {
/* set new timeout */
now = apr_time_now();
ccfg->timeout_at = now + apr_time_from_sec(ccfg->cur_stage.timeout);
ccfg->cur_stage.timeout = 0;
if (ccfg->cur_stage.max_timeout > 0) {
ccfg->max_timeout_at = now + apr_time_from_sec(ccfg->cur_stage.max_timeout);
ccfg->cur_stage.max_timeout = 0;
}
}
else if (ccfg->timeout_at == 0) {
/* no timeout set, or in between requests */
return ap_get_brigade(f->next, bb, mode, block, readbytes);
}
if (!ccfg->socket) {
ccfg->socket = ap_get_conn_socket(f->c);
}
rv = check_time_left(ccfg, &time_left, now);
if (rv != APR_SUCCESS)
goto out;
if (block == APR_NONBLOCK_READ || mode == AP_MODE_INIT
|| mode == AP_MODE_EATCRLF) {
rv = ap_get_brigade(f->next, bb, mode, block, readbytes);
if (ccfg->cur_stage.rate_factor && rv == APR_SUCCESS) {
extend_timeout(ccfg, bb);
}
return rv;
}
rv = apr_socket_timeout_get(ccfg->socket, &saved_sock_timeout);
AP_DEBUG_ASSERT(rv == APR_SUCCESS);
rv = apr_socket_timeout_set(ccfg->socket, MIN(time_left, saved_sock_timeout));
AP_DEBUG_ASSERT(rv == APR_SUCCESS);
if (mode == AP_MODE_GETLINE) {
/*
* For a blocking AP_MODE_GETLINE read, apr_brigade_split_line()
* would loop until a whole line has been read. As this would make it
* impossible to enforce a total timeout, we only do non-blocking
* reads.
*/
apr_off_t remaining = HUGE_STRING_LEN;
do {
apr_off_t bblen;
#if APR_MAJOR_VERSION < 2
apr_int32_t nsds;
apr_interval_time_t poll_timeout;
apr_pollfd_t pollset;
#endif
rv = ap_get_brigade(f->next, bb, AP_MODE_GETLINE, APR_NONBLOCK_READ, remaining);
if (rv != APR_SUCCESS && !APR_STATUS_IS_EAGAIN(rv)) {
break;
}
if (!APR_BRIGADE_EMPTY(bb)) {
if (ccfg->cur_stage.rate_factor) {
extend_timeout(ccfg, bb);
}
rv = have_lf_or_eos(bb);
if (rv != APR_INCOMPLETE) {
break;
}
rv = apr_brigade_length(bb, 1, &bblen);
if (rv != APR_SUCCESS) {
break;
}
remaining -= bblen;
if (remaining <= 0) {
break;
}
/* Haven't got a whole line yet, save what we have ... */
if (!ccfg->tmpbb) {
ccfg->tmpbb = apr_brigade_create(f->c->pool, f->c->bucket_alloc);
}
rv = brigade_append(ccfg->tmpbb, bb);
if (rv != APR_SUCCESS)
break;
}
/* ... and wait for more */
#if APR_MAJOR_VERSION < 2
pollset.p = f->c->pool;
pollset.desc_type = APR_POLL_SOCKET;
pollset.reqevents = APR_POLLIN|APR_POLLHUP;
pollset.desc.s = ccfg->socket;
apr_socket_timeout_get(ccfg->socket, &poll_timeout);
rv = apr_poll(&pollset, 1, &nsds, poll_timeout);
#else
rv = apr_socket_wait(ccfg->socket, APR_WAIT_READ);
#endif
if (rv != APR_SUCCESS)
break;
rv = check_time_left(ccfg, &time_left, 0);
if (rv != APR_SUCCESS)
break;
rv = apr_socket_timeout_set(ccfg->socket,
MIN(time_left, saved_sock_timeout));
AP_DEBUG_ASSERT(rv == APR_SUCCESS);
} while (1);
if (ccfg->tmpbb)
APR_BRIGADE_PREPEND(bb, ccfg->tmpbb);
}
else { /* mode != AP_MODE_GETLINE */
rv = ap_get_brigade(f->next, bb, mode, block, readbytes);
/* Don't extend the timeout in speculative mode, wait for
* the real (relevant) bytes to be asked later, within the
* currently allotted time.
*/
if (ccfg->cur_stage.rate_factor && rv == APR_SUCCESS
&& mode != AP_MODE_SPECULATIVE) {
extend_timeout(ccfg, bb);
}
}
apr_socket_timeout_set(ccfg->socket, saved_sock_timeout);
out:
if (APR_STATUS_IS_TIMEUP(rv)) {
ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, f->c, APLOGNO(01382)
"Request %s read timeout", ccfg->type);
/*
* If we allow a normal lingering close, the client may keep this
* process/thread busy for another 30s (MAX_SECS_TO_LINGER).
* Therefore we tell ap_lingering_close() to shorten this period to
* 2s (SECONDS_TO_LINGER).
*/
apr_table_setn(f->c->notes, "short-lingering-close", "1");
/*
* Also, we must not allow keep-alive requests, as
* ap_finalize_protocol() may ignore our error status (if the timeout
* happened on a request body that is discarded).
*/
f->c->keepalive = AP_CONN_CLOSE;
}
return rv;
}
static apr_status_t reqtimeout_eor(ap_filter_t *f, apr_bucket_brigade *bb)
{
if (!APR_BRIGADE_EMPTY(bb) && AP_BUCKET_IS_EOR(APR_BRIGADE_LAST(bb))) {
reqtimeout_con_cfg *ccfg = f->ctx;
ccfg->timeout_at = 0;
}
return ap_pass_brigade(f->next, bb);
}
#define INIT_STAGE(cfg, ccfg, stage) do { \
if (cfg->stage.timeout != UNSET) { \
ccfg->cur_stage.timeout = cfg->stage.timeout; \
ccfg->cur_stage.max_timeout = cfg->stage.max_timeout; \
ccfg->cur_stage.rate_factor = cfg->stage.rate_factor; \
} \
else { \
ccfg->cur_stage.timeout = MRT_DEFAULT_##stage##_TIMEOUT; \
ccfg->cur_stage.max_timeout = MRT_DEFAULT_##stage##_MAX_TIMEOUT; \
ccfg->cur_stage.rate_factor = default_##stage##_rate_factor; \
} \
} while (0)
static int reqtimeout_init(conn_rec *c)
{
reqtimeout_con_cfg *ccfg;
reqtimeout_srv_cfg *cfg;
cfg = ap_get_module_config(c->base_server->module_config,
&reqtimeout_module);
AP_DEBUG_ASSERT(cfg != NULL);
/* For compatibility, handshake timeout is disabled when UNSET (< 0) */
if (cfg->handshake.timeout <= 0
&& cfg->header.timeout == 0
&& cfg->body.timeout == 0) {
/* disabled for this vhost */
return DECLINED;
}
ccfg = ap_get_module_config(c->conn_config, &reqtimeout_module);
if (ccfg == NULL) {
ccfg = apr_pcalloc(c->pool, sizeof(reqtimeout_con_cfg));
ap_set_module_config(c->conn_config, &reqtimeout_module, ccfg);
ap_add_output_filter(reqtimeout_filter_name, ccfg, NULL, c);
ap_add_input_filter(reqtimeout_filter_name, ccfg, NULL, c);
ccfg->type = "handshake";
if (cfg->handshake.timeout > 0) {
INIT_STAGE(cfg, ccfg, handshake);
}
}
/* we are not handling the connection, we just do initialization */
return DECLINED;
}
static void reqtimeout_before_header(request_rec *r, conn_rec *c)
{
reqtimeout_srv_cfg *cfg;
reqtimeout_con_cfg *ccfg =
ap_get_module_config(c->conn_config, &reqtimeout_module);
if (ccfg == NULL) {
/* not configured for this connection */
return;
}
cfg = ap_get_module_config(c->base_server->module_config,
&reqtimeout_module);
AP_DEBUG_ASSERT(cfg != NULL);
/* (Re)set the state for this new request, but ccfg->socket and
* ccfg->tmpbb which have the lifetime of the connection.
*/
ccfg->type = "header";
ccfg->timeout_at = 0;
ccfg->max_timeout_at = 0;
ccfg->in_keep_alive = (c->keepalives > 0);
INIT_STAGE(cfg, ccfg, header);
}
static int reqtimeout_before_body(request_rec *r)
{
reqtimeout_srv_cfg *cfg;
reqtimeout_con_cfg *ccfg =
ap_get_module_config(r->connection->conn_config, &reqtimeout_module);
if (ccfg == NULL) {
/* not configured for this connection */
return OK;
}
cfg = ap_get_module_config(r->server->module_config,
&reqtimeout_module);
AP_DEBUG_ASSERT(cfg != NULL);
ccfg->type = "body";
ccfg->timeout_at = 0;
ccfg->max_timeout_at = 0;
if (r->method_number == M_CONNECT) {
/* disabled for a CONNECT request */
ccfg->cur_stage.timeout = 0;
}
else {
INIT_STAGE(cfg, ccfg, body);
}
return OK;
}
#define UNSET_STAGE(cfg, stage) do { \
cfg->stage.timeout = UNSET; \
cfg->stage.max_timeout = UNSET; \
cfg->stage.min_rate = UNSET; \
} while (0)
static void *reqtimeout_create_srv_config(apr_pool_t *p, server_rec *s)
{
reqtimeout_srv_cfg *cfg = apr_pcalloc(p, sizeof(reqtimeout_srv_cfg));
UNSET_STAGE(cfg, handshake);
UNSET_STAGE(cfg, header);
UNSET_STAGE(cfg, body);
return cfg;
}
#define MERGE_INT(cfg, base, add, val) \
cfg->val = (add->val == UNSET) ? base->val : add->val
#define MERGE_STAGE(cfg, base, add, stage) do { \
MERGE_INT(cfg, base, add, stage.timeout); \
MERGE_INT(cfg, base, add, stage.max_timeout); \
MERGE_INT(cfg, base, add, stage.min_rate); \
cfg->stage.rate_factor = (cfg->stage.min_rate == UNSET) \
? base->stage.rate_factor \
: add->stage.rate_factor; \
} while (0)
static void *reqtimeout_merge_srv_config(apr_pool_t *p, void *base_, void *add_)
{
reqtimeout_srv_cfg *base = base_;
reqtimeout_srv_cfg *add = add_;
reqtimeout_srv_cfg *cfg = apr_pcalloc(p, sizeof(reqtimeout_srv_cfg));
MERGE_STAGE(cfg, base, add, handshake);
MERGE_STAGE(cfg, base, add, header);
MERGE_STAGE(cfg, base, add, body);
return cfg;
}
static const char *parse_int(apr_pool_t *p, const char *arg, int *val)
{
char *endptr;
*val = strtol(arg, &endptr, 10);
if (arg == endptr) {
return apr_psprintf(p, "Value '%s' not numerical", endptr);
}
if (*endptr != '\0') {
return apr_psprintf(p, "Cannot parse '%s'", endptr);
}
if (*val < 0) {
return "Value must be non-negative";
}
return NULL;
}
static const char *set_reqtimeout_param(reqtimeout_srv_cfg *conf,
apr_pool_t *p,
const char *key,
const char *val)
{
const char *ret = NULL;
char *rate_str = NULL, *initial_str, *max_str = NULL;
reqtimeout_stage_t *stage;
if (!strcasecmp(key, "handshake")) {
stage = &conf->handshake;
}
else if (!strcasecmp(key, "header")) {
stage = &conf->header;
}
else if (!strcasecmp(key, "body")) {
stage = &conf->body;
}
else {
return "Unknown RequestReadTimeout parameter";
}
memset(stage, 0, sizeof(*stage));
if ((rate_str = ap_strcasestr(val, ",minrate="))) {
initial_str = apr_pstrndup(p, val, rate_str - val);
rate_str += strlen(",minrate=");
ret = parse_int(p, rate_str, &stage->min_rate);
if (ret)
return ret;
if (stage->min_rate == 0)
return "Minimum data rate must be larger than 0";
if ((max_str = strchr(initial_str, '-'))) {
*max_str++ = '\0';
ret = parse_int(p, max_str, &stage->max_timeout);
if (ret)
return ret;
}
ret = parse_int(p, initial_str, &stage->timeout);
}
else {
if (ap_strchr_c(val, '-'))
return "Must set MinRate option if using timeout range";
ret = parse_int(p, val, &stage->timeout);
}
if (ret)
return ret;
if (stage->max_timeout && stage->timeout >= stage->max_timeout) {
return "Maximum timeout must be larger than initial timeout";
}
if (stage->min_rate) {
stage->rate_factor = apr_time_from_sec(1) / stage->min_rate;
}
return NULL;
}
static const char *set_reqtimeouts(cmd_parms *cmd, void *mconfig,
const char *arg)
{
reqtimeout_srv_cfg *conf =
ap_get_module_config(cmd->server->module_config,
&reqtimeout_module);
while (*arg) {
char *word, *val;
const char *err;
word = ap_getword_conf(cmd->temp_pool, &arg);
val = strchr(word, '=');
if (!val) {
return "Invalid RequestReadTimeout parameter. Parameter must be "
"in the form 'key=value'";
}
else
*val++ = '\0';
err = set_reqtimeout_param(conf, cmd->pool, word, val);
if (err)
return apr_psprintf(cmd->temp_pool, "RequestReadTimeout: %s=%s: %s",
word, val, err);
}
return NULL;
}
static void reqtimeout_hooks(apr_pool_t *pool)
{
/*
* mod_ssl is AP_FTYPE_CONNECTION + 5 and mod_reqtimeout needs to
* be called before mod_ssl for the handshake stage to catch SSL traffic.
*/
ap_register_input_filter(reqtimeout_filter_name, reqtimeout_filter, NULL,
AP_FTYPE_CONNECTION + 8);
/*
* We need to pause timeout detection in between requests, for
* speculative and non-blocking reads, so between each outgoing EOR
* and the next pre_read_request call.
*/
ap_register_output_filter(reqtimeout_filter_name, reqtimeout_eor, NULL,
AP_FTYPE_CONNECTION);
/*
* mod_reqtimeout needs to be called before ap_process_http_request (which
* is run at APR_HOOK_REALLY_LAST) but after all other protocol modules.
* This ensures that it only influences normal http connections and not
* e.g. mod_ftp. We still process it first though, for the handshake stage
* to work with/before mod_ssl, but since it's disabled by default it won't
* influence non-HTTP modules unless configured explicitly. Also, if
* mod_reqtimeout used the pre_connection hook, it would be inserted on
* mod_proxy's backend connections, and we don't want this.
*/
ap_hook_process_connection(reqtimeout_init, NULL, NULL, APR_HOOK_FIRST);
ap_hook_pre_read_request(reqtimeout_before_header, NULL, NULL,
APR_HOOK_MIDDLE);
ap_hook_post_read_request(reqtimeout_before_body, NULL, NULL,
APR_HOOK_MIDDLE);
#if MRT_DEFAULT_handshake_MIN_RATE
default_handshake_rate_factor = apr_time_from_sec(1) /
MRT_DEFAULT_handshake_MIN_RATE;
#endif
#if MRT_DEFAULT_header_MIN_RATE
default_header_rate_factor = apr_time_from_sec(1) /
MRT_DEFAULT_header_MIN_RATE;
#endif
#if MRT_DEFAULT_body_MIN_RATE
default_body_rate_factor = apr_time_from_sec(1) /
MRT_DEFAULT_body_MIN_RATE;
#endif
}
static const command_rec reqtimeout_cmds[] = {
AP_INIT_RAW_ARGS("RequestReadTimeout", set_reqtimeouts, NULL, RSRC_CONF,
"Set various timeout parameters for TLS handshake and/or "
"reading request headers and body"),
{NULL}
};
AP_DECLARE_MODULE(reqtimeout) = {
STANDARD20_MODULE_STUFF,
NULL, /* create per-dir config structures */
NULL, /* merge per-dir config structures */
reqtimeout_create_srv_config, /* create per-server config structures */
reqtimeout_merge_srv_config, /* merge per-server config structures */
reqtimeout_cmds, /* table of config file commands */
reqtimeout_hooks
};