/* 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 "mod_proxy.h"
#include "mod_watchdog.h"
#include "ap_slotmem.h"
#include "ap_expr.h"
#if APR_HAS_THREADS
#include "apr_thread_pool.h"
#endif
module AP_MODULE_DECLARE_DATA proxy_hcheck_module;
#define HCHECK_WATHCHDOG_NAME ("_proxy_hcheck_")
#define HC_THREADPOOL_SIZE (16)
/* Why? So we can easily set/clear HC_USE_THREADS during dev testing */
#if APR_HAS_THREADS
#ifndef HC_USE_THREADS
#define HC_USE_THREADS 1
#endif
#else
#define HC_USE_THREADS 0
typedef void apr_thread_pool_t;
#endif
typedef struct {
char *name;
hcmethod_t method;
int passes;
int fails;
apr_interval_time_t interval;
char *hurl;
char *hcexpr;
} hc_template_t;
typedef struct {
char *expr;
ap_expr_info_t *pexpr; /* parsed expression */
} hc_condition_t;
typedef struct {
apr_pool_t *p;
apr_array_header_t *templates;
apr_table_t *conditions;
apr_hash_t *hcworkers;
server_rec *s;
} sctx_t;
/* Used in the HC worker via the context field */
typedef struct {
const char *path; /* The path of the original worker URL */
const char *method; /* Method string for the HTTP/AJP request */
const char *req; /* pre-formatted HTTP/AJP request */
proxy_worker *w; /* Pointer to the actual worker */
} wctx_t;
typedef struct {
apr_pool_t *ptemp;
sctx_t *ctx;
proxy_balancer *balancer;
proxy_worker *worker;
proxy_worker *hc;
apr_time_t now;
} baton_t;
static void *hc_create_config(apr_pool_t *p, server_rec *s)
{
sctx_t *ctx = apr_pcalloc(p, sizeof(sctx_t));
ctx->s = s;
apr_pool_create(&ctx->p, p);
apr_pool_tag(ctx->p, "proxy_hcheck");
ctx->templates = apr_array_make(p, 10, sizeof(hc_template_t));
ctx->conditions = apr_table_make(p, 10);
ctx->hcworkers = apr_hash_make(p);
return ctx;
}
static ap_watchdog_t *watchdog;
static int tpsize = HC_THREADPOOL_SIZE;
/*
* This serves double duty by not only validating (and creating)
* the health-check template, but also ties into set_worker_param()
* which does the actual setting of worker params in shm.
*/
static const char *set_worker_hc_param(apr_pool_t *p,
server_rec *s,
proxy_worker *worker,
const char *key,
const char *val,
void *v)
{
int ival;
hc_template_t *temp;
sctx_t *ctx = (sctx_t *) ap_get_module_config(s->module_config,
&proxy_hcheck_module);
if (!worker && !v) {
return "Bad call to set_worker_hc_param()";
}
temp = (hc_template_t *)v;
if (!strcasecmp(key, "hctemplate")) {
hc_template_t *template;
template = (hc_template_t *)ctx->templates->elts;
for (ival = 0; ival < ctx->templates->nelts; ival++, template++) {
if (!ap_cstr_casecmp(template->name, val)) {
if (worker) {
worker->s->method = template->method;
worker->s->interval = template->interval;
worker->s->passes = template->passes;
worker->s->fails = template->fails;
PROXY_STRNCPY(worker->s->hcuri, template->hurl);
PROXY_STRNCPY(worker->s->hcexpr, template->hcexpr);
} else {
temp->method = template->method;
temp->interval = template->interval;
temp->passes = template->passes;
temp->fails = template->fails;
temp->hurl = apr_pstrdup(p, template->hurl);
temp->hcexpr = apr_pstrdup(p, template->hcexpr);
}
return NULL;
}
}
return apr_psprintf(p, "Unknown ProxyHCTemplate name: %s", val);
}
else if (!strcasecmp(key, "hcmethod")) {
proxy_hcmethods_t *method = proxy_hcmethods;
for (; method->name; method++) {
if (!ap_cstr_casecmp(val, method->name)) {
if (!method->implemented) {
return apr_psprintf(p, "Health check method %s not (yet) implemented",
val);
}
if (worker) {
worker->s->method = method->method;
} else {
temp->method = method->method;
}
return NULL;
}
}
return "Unknown method";
}
else if (!strcasecmp(key, "hcinterval")) {
apr_interval_time_t hci;
apr_status_t rv;
rv = ap_timeout_parameter_parse(val, &hci, "s");
if (rv != APR_SUCCESS)
return "Unparse-able hcinterval setting";
if (hci < AP_WD_TM_SLICE)
return apr_psprintf(p, "Interval must be a positive value greater than %"
APR_TIME_T_FMT "ms", apr_time_as_msec(AP_WD_TM_SLICE));
if (worker) {
worker->s->interval = hci;
} else {
temp->interval = hci;
}
}
else if (!strcasecmp(key, "hcpasses")) {
ival = atoi(val);
if (ival < 0)
return "Passes must be a positive value";
if (worker) {
worker->s->passes = ival;
} else {
temp->passes = ival;
}
}
else if (!strcasecmp(key, "hcfails")) {
ival = atoi(val);
if (ival < 0)
return "Fails must be a positive value";
if (worker) {
worker->s->fails = ival;
} else {
temp->fails = ival;
}
}
else if (!strcasecmp(key, "hcuri")) {
if (strlen(val) >= sizeof(worker->s->hcuri))
return apr_psprintf(p, "Health check uri length must be < %d characters",
(int)sizeof(worker->s->hcuri));
if (worker) {
PROXY_STRNCPY(worker->s->hcuri, val);
} else {
temp->hurl = apr_pstrdup(p, val);
}
}
else if (!strcasecmp(key, "hcexpr")) {
hc_condition_t *cond;
cond = (hc_condition_t *)apr_table_get(ctx->conditions, val);
if (!cond) {
return apr_psprintf(p, "Unknown health check condition expr: %s", val);
}
/* This check is wonky... a known expr can't be this big. Check anyway */
if (strlen(val) >= sizeof(worker->s->hcexpr))
return apr_psprintf(p, "Health check uri length must be < %d characters",
(int)sizeof(worker->s->hcexpr));
if (worker) {
PROXY_STRNCPY(worker->s->hcexpr, val);
} else {
temp->hcexpr = apr_pstrdup(p, val);
}
}
else {
return "unknown Worker hcheck parameter";
}
return NULL;
}
static const char *set_hc_condition(cmd_parms *cmd, void *dummy, const char *arg)
{
char *name = NULL;
char *expr;
sctx_t *ctx;
hc_condition_t *cond;
const char *err = ap_check_cmd_context(cmd, NOT_IN_HTACCESS);
if (err)
return err;
ctx = (sctx_t *) ap_get_module_config(cmd->server->module_config,
&proxy_hcheck_module);
name = ap_getword_conf(cmd->pool, &arg);
if (!*name) {
return apr_pstrcat(cmd->temp_pool, "Missing expression name for ",
cmd->cmd->name, NULL);
}
if (strlen(name) > (PROXY_WORKER_MAX_SCHEME_SIZE - 1)) {
return apr_psprintf(cmd->temp_pool, "Expression name limited to %d characters",
(PROXY_WORKER_MAX_SCHEME_SIZE - 1));
}
/* get expr. Allow fancy new {...} quoting style */
expr = ap_getword_conf2(cmd->temp_pool, &arg);
if (!*expr) {
return apr_pstrcat(cmd->temp_pool, "Missing expression for ",
cmd->cmd->name, NULL);
}
cond = apr_palloc(cmd->pool, sizeof(hc_condition_t));
cond->pexpr = ap_expr_parse_cmd(cmd, expr, 0, &err, NULL);
if (err) {
return apr_psprintf(cmd->temp_pool, "Could not parse expression \"%s\": %s",
expr, err);
}
cond->expr = apr_pstrdup(cmd->pool, expr);
apr_table_setn(ctx->conditions, name, (void *)cond);
expr = ap_getword_conf(cmd->temp_pool, &arg);
if (*expr) {
return "error: extra parameter(s)";
}
return NULL;
}
static const char *set_hc_template(cmd_parms *cmd, void *dummy, const char *arg)
{
char *name = NULL;
char *word, *val;
hc_template_t *template;
sctx_t *ctx;
const char *err = ap_check_cmd_context(cmd, NOT_IN_HTACCESS);
if (err)
return err;
ctx = (sctx_t *) ap_get_module_config(cmd->server->module_config,
&proxy_hcheck_module);
name = ap_getword_conf(cmd->temp_pool, &arg);
if (!*name) {
return apr_pstrcat(cmd->temp_pool, "Missing template name for ",
cmd->cmd->name, NULL);
}
template = (hc_template_t *)apr_array_push(ctx->templates);
template->name = apr_pstrdup(cmd->pool, name);
template->method = template->passes = template->fails = 1;
template->interval = apr_time_from_sec(HCHECK_WATHCHDOG_DEFAULT_INTERVAL);
template->hurl = NULL;
template->hcexpr = NULL;
while (*arg) {
word = ap_getword_conf(cmd->pool, &arg);
val = strchr(word, '=');
if (!val) {
return "Invalid ProxyHCTemplate parameter. Parameter must be "
"in the form 'key=value'";
}
else
*val++ = '\0';
err = set_worker_hc_param(cmd->pool, ctx->s, NULL, word, val, template);
if (err) {
/* get rid of recently pushed (bad) template */
apr_array_pop(ctx->templates);
return apr_pstrcat(cmd->temp_pool, "ProxyHCTemplate: ", err, " ", word, "=", val, "; ", name, NULL);
}
/* No error means we have a valid template */
}
return NULL;
}
#if HC_USE_THREADS
static const char *set_hc_tpsize (cmd_parms *cmd, void *dummy, const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err)
return err;
tpsize = atoi(arg);
if (tpsize < 0)
return "Invalid ProxyHCTPsize parameter. Parameter must be "
">= 0";
return NULL;
}
#endif
/*
* Create a dummy request rec, simply so we can use ap_expr.
* Use our short-lived pool for bucket_alloc so that we can simply move
* buckets and use them after the backend connection is released.
*/
static request_rec *create_request_rec(apr_pool_t *p, server_rec *s,
proxy_balancer *balancer,
const char *method)
{
request_rec *r;
r = apr_pcalloc(p, sizeof(request_rec));
r->pool = p;
r->server = s;
r->per_dir_config = r->server->lookup_defaults;
if (balancer->section_config) {
r->per_dir_config = ap_merge_per_dir_configs(r->pool,
r->per_dir_config,
balancer->section_config);
}
r->proxyreq = PROXYREQ_RESPONSE;
r->user = NULL;
r->ap_auth_type = NULL;
r->allowed_methods = ap_make_method_list(p, 2);
r->headers_in = apr_table_make(r->pool, 1);
r->trailers_in = apr_table_make(r->pool, 1);
r->subprocess_env = apr_table_make(r->pool, 25);
r->headers_out = apr_table_make(r->pool, 12);
r->err_headers_out = apr_table_make(r->pool, 5);
r->trailers_out = apr_table_make(r->pool, 1);
r->notes = apr_table_make(r->pool, 5);
r->request_config = ap_create_request_config(r->pool);
/* Must be set before we run create request hook */
r->sent_bodyct = 0; /* bytect isn't for body */
r->read_length = 0;
r->read_body = REQUEST_NO_BODY;
r->status = HTTP_OK; /* Until further notice */
r->the_request = NULL;
/* Begin by presuming any module can make its own path_info assumptions,
* until some module interjects and changes the value.
*/
r->used_path_info = AP_REQ_DEFAULT_PATH_INFO;
/* Time to populate r with the data we have. */
r->method = method;
/* Provide quick information about the request method as soon as known */
r->method_number = ap_method_number_of(r->method);
if (r->method_number == M_OPTIONS
|| (r->method_number == M_GET && r->method[0] == 'H')) {
r->header_only = 1;
}
else {
r->header_only = 0;
}
r->protocol = "HTTP/1.0";
r->proto_num = HTTP_VERSION(1, 0);
r->hostname = NULL;
return r;
}
static void set_request_connection(request_rec *r, conn_rec *conn)
{
conn->bucket_alloc = apr_bucket_alloc_create(r->pool);
r->connection = conn;
r->kept_body = apr_brigade_create(r->pool, conn->bucket_alloc);
r->output_filters = r->proto_output_filters = conn->output_filters;
r->input_filters = r->proto_input_filters = conn->input_filters;
r->useragent_addr = conn->client_addr;
r->useragent_ip = conn->client_ip;
}
static void create_hcheck_req(wctx_t *wctx, proxy_worker *hc,
apr_pool_t *p)
{
char *req = NULL;
const char *method = NULL;
switch (hc->s->method) {
case OPTIONS:
method = "OPTIONS";
req = apr_psprintf(p,
"OPTIONS * HTTP/1.0\r\n"
"Host: %s:%d\r\n"
"\r\n",
hc->s->hostname_ex, (int)hc->s->port);
break;
case HEAD:
method = "HEAD";
/* fallthru */
case GET:
if (!method) { /* did we fall thru? If not, we are GET */
method = "GET";
}
req = apr_psprintf(p,
"%s %s%s%s HTTP/1.0\r\n"
"Host: %s:%d\r\n"
"\r\n",
method,
(wctx->path ? wctx->path : ""),
(wctx->path && *hc->s->hcuri ? "/" : "" ),
(*hc->s->hcuri ? hc->s->hcuri : ""),
hc->s->hostname_ex, (int)hc->s->port);
break;
default:
break;
}
wctx->req = req;
wctx->method = method;
}
static proxy_worker *hc_get_hcworker(sctx_t *ctx, proxy_worker *worker,
apr_pool_t *p)
{
proxy_worker *hc = NULL;
apr_port_t port;
hc = (proxy_worker *)apr_hash_get(ctx->hcworkers, &worker, sizeof worker);
if (!hc) {
apr_uri_t uri;
apr_status_t rv;
const char *url = worker->s->name;
wctx_t *wctx = apr_pcalloc(ctx->p, sizeof(wctx_t));
port = (worker->s->port ? worker->s->port
: ap_proxy_port_of_scheme(worker->s->scheme));
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ctx->s, APLOGNO(03248)
"Creating hc worker %pp for %s://%s:%d",
worker, worker->s->scheme, worker->s->hostname_ex,
(int)port);
ap_proxy_define_worker(ctx->p, &hc, NULL, NULL, worker->s->name, 0);
apr_snprintf(hc->s->name, sizeof hc->s->name, "%pp", worker);
PROXY_STRNCPY(hc->s->hostname, worker->s->hostname); /* for compatibility */
PROXY_STRNCPY(hc->s->hostname_ex, worker->s->hostname_ex);
PROXY_STRNCPY(hc->s->scheme, worker->s->scheme);
PROXY_STRNCPY(hc->s->hcuri, worker->s->hcuri);
PROXY_STRNCPY(hc->s->hcexpr, worker->s->hcexpr);
hc->hash.def = hc->s->hash.def = ap_proxy_hashfunc(hc->s->name, PROXY_HASHFUNC_DEFAULT);
hc->hash.fnv = hc->s->hash.fnv = ap_proxy_hashfunc(hc->s->name, PROXY_HASHFUNC_FNV);
hc->s->port = port;
/* Do not disable worker in case of errors */
hc->s->status |= PROXY_WORKER_IGNORE_ERRORS;
/* Mark as the "generic" worker */
hc->s->status |= PROXY_WORKER_GENERIC;
ap_proxy_initialize_worker(hc, ctx->s, ctx->p);
hc->s->is_address_reusable = worker->s->is_address_reusable;
hc->s->disablereuse = worker->s->disablereuse;
hc->s->method = worker->s->method;
rv = apr_uri_parse(p, url, &uri);
if (rv == APR_SUCCESS) {
wctx->path = apr_pstrdup(ctx->p, uri.path);
}
wctx->w = worker;
create_hcheck_req(wctx, hc, ctx->p);
hc->context = wctx;
apr_hash_set(ctx->hcworkers, &worker, sizeof worker, hc);
}
/* This *could* have changed via the Balancer Manager */
/* TODO */
if (hc->s->method != worker->s->method) {
wctx_t *wctx = hc->context;
port = (worker->s->port ? worker->s->port
: ap_proxy_port_of_scheme(worker->s->scheme));
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ctx->s, APLOGNO(03311)
"Updating hc worker %pp for %s://%s:%d",
worker, worker->s->scheme, worker->s->hostname_ex,
(int)port);
hc->s->method = worker->s->method;
create_hcheck_req(wctx, hc, ctx->p);
}
return hc;
}
static int hc_determine_connection(sctx_t *ctx, proxy_worker *worker,
apr_sockaddr_t **addr, apr_pool_t *p)
{
apr_status_t rv = APR_SUCCESS;
/*
* normally, this is done in ap_proxy_determine_connection().
* TODO: Look at using ap_proxy_determine_connection() with a
* fake request_rec
*/
if (worker->cp->addr) {
*addr = worker->cp->addr;
}
else {
rv = apr_sockaddr_info_get(addr, worker->s->hostname_ex,
APR_UNSPEC, worker->s->port, 0, p);
if (rv != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ctx->s, APLOGNO(03249)
"DNS lookup failure for: %s:%d",
worker->s->hostname_ex, (int)worker->s->port);
}
}
return (rv == APR_SUCCESS ? OK : !OK);
}
static apr_status_t hc_init_worker(sctx_t *ctx, proxy_worker *worker)
{
apr_status_t rv = APR_SUCCESS;
/*
* Since this is the watchdog, workers never actually handle a
* request here, and so the local data isn't initialized (of
* course, the shared memory is). So we need to bootstrap
* worker->cp. Note, we only need do this once.
*/
if (!worker->cp) {
rv = ap_proxy_initialize_worker(worker, ctx->s, ctx->p);
if (rv != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ctx->s, APLOGNO(03250) "Cannot init worker");
return rv;
}
if (worker->s->is_address_reusable && !worker->s->disablereuse &&
hc_determine_connection(ctx, worker, &worker->cp->addr,
worker->cp->pool) != OK) {
rv = APR_EGENERAL;
}
}
return rv;
}
static apr_status_t backend_cleanup(const char *proxy_function, proxy_conn_rec *backend,
server_rec *s, int status)
{
if (backend) {
backend->close = 1;
ap_proxy_release_connection(proxy_function, backend, s);
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(03251)
"Health check %s Status (%d) for %s.",
ap_proxy_show_hcmethod(backend->worker->s->method),
status,
backend->worker->s->name);
}
if (status != OK) {
return APR_EGENERAL;
}
return APR_SUCCESS;
}
static int hc_get_backend(const char *proxy_function, proxy_conn_rec **backend,
proxy_worker *hc, sctx_t *ctx, apr_pool_t *ptemp)
{
int status;
status = ap_proxy_acquire_connection(proxy_function, backend, hc, ctx->s);
if (status == OK) {
(*backend)->addr = hc->cp->addr;
(*backend)->hostname = hc->s->hostname_ex;
if (strcmp(hc->s->scheme, "https") == 0) {
if (!ap_proxy_ssl_enable(NULL)) {
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ctx->s, APLOGNO(03252)
"mod_ssl not configured?");
return !OK;
}
(*backend)->is_ssl = 1;
}
}
return hc_determine_connection(ctx, hc, &(*backend)->addr, ptemp);
}
static apr_status_t hc_check_tcp(baton_t *baton)
{
int status;
sctx_t *ctx = baton->ctx;
proxy_worker *hc = baton->hc;
proxy_conn_rec *backend = NULL;
status = hc_get_backend("HCTCP", &backend, hc, ctx, baton->ptemp);
if (status == OK) {
status = ap_proxy_connect_backend("HCTCP", backend, hc, ctx->s);
/* does an unconditional ap_proxy_is_socket_connected() */
}
return backend_cleanup("HCTCP", backend, ctx->s, status);
}
static int hc_send(request_rec *r, const char *out, apr_bucket_brigade *bb)
{
apr_status_t rv;
conn_rec *c = r->connection;
apr_bucket_alloc_t *ba = c->bucket_alloc;
ap_log_error(APLOG_MARK, APLOG_TRACE7, 0, r->server, "%s", out);
APR_BRIGADE_INSERT_TAIL(bb, apr_bucket_pool_create(out, strlen(out),
r->pool, ba));
APR_BRIGADE_INSERT_TAIL(bb, apr_bucket_flush_create(ba));
rv = ap_pass_brigade(c->output_filters, bb);
apr_brigade_cleanup(bb);
return (rv) ? !OK : OK;
}
static int hc_read_headers(request_rec *r)
{
char buffer[HUGE_STRING_LEN];
int len;
len = ap_getline(buffer, sizeof(buffer), r, 1);
if (len <= 0) {
return !OK;
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, APLOGNO(03254)
"%.*s", len, buffer);
/* for the below, see ap_proxy_http_process_response() */
if (apr_date_checkmask(buffer, "HTTP/#.# ###*")) {
int major;
char keepchar;
int proxy_status = OK;
const char *proxy_status_line = NULL;
major = buffer[5] - '0';
if ((major != 1) || (len >= sizeof(buffer)-1)) {
return !OK;
}
keepchar = buffer[12];
buffer[12] = '\0';
proxy_status = atoi(&buffer[9]);
if (keepchar != '\0') {
buffer[12] = keepchar;
} else {
buffer[12] = ' ';
buffer[13] = '\0';
}
proxy_status_line = apr_pstrdup(r->pool, &buffer[9]);
r->status = proxy_status;
r->status_line = proxy_status_line;
} else {
return !OK;
}
/* OK, 1st line is OK... scarf in the headers */
while ((len = ap_getline(buffer, sizeof(buffer), r, 1)) > 0) {
char *value, *end;
ap_log_error(APLOG_MARK, APLOG_TRACE7, 0, r->server, "%.*s",
len, buffer);
if (!(value = strchr(buffer, ':'))) {
return !OK;
}
*value = '\0';
++value;
while (apr_isspace(*value))
++value; /* Skip to start of value */
for (end = &value[strlen(value)-1]; end > value && apr_isspace(*end); --end)
*end = '\0';
apr_table_add(r->headers_out, buffer, value);
}
return OK;
}
static int hc_read_body(request_rec *r, apr_bucket_brigade *bb)
{
apr_status_t rv = APR_SUCCESS;
int seen_eos = 0;
do {
apr_size_t len = HUGE_STRING_LEN;
apr_brigade_cleanup(bb);
rv = ap_get_brigade(r->proto_input_filters, bb, AP_MODE_READBYTES,
APR_BLOCK_READ, len);
if (rv != APR_SUCCESS) {
if (APR_STATUS_IS_EOF(rv)) {
rv = APR_SUCCESS;
break;
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, r->server, APLOGNO(03300)
"Error reading response body");
break;
}
while (!APR_BRIGADE_EMPTY(bb)) {
apr_bucket *bucket = APR_BRIGADE_FIRST(bb);
if (APR_BUCKET_IS_EOS(bucket)) {
seen_eos = 1;
break;
}
if (APR_BUCKET_IS_FLUSH(bucket)) {
apr_bucket_delete(bucket);
continue;
}
APR_BUCKET_REMOVE(bucket);
APR_BRIGADE_INSERT_TAIL(r->kept_body, bucket);
}
}
while (!seen_eos);
apr_brigade_cleanup(bb);
return (rv == APR_SUCCESS ? OK : !OK);
}
/*
* Send the HTTP OPTIONS, HEAD or GET request to the backend
* server associated w/ worker. If we have Conditions,
* then apply those to the resulting response, otherwise
* any status code 2xx or 3xx is considered "passing"
*/
static apr_status_t hc_check_http(baton_t *baton)
{
int status;
proxy_conn_rec *backend = NULL;
sctx_t *ctx = baton->ctx;
proxy_worker *hc = baton->hc;
proxy_worker *worker = baton->worker;
apr_pool_t *ptemp = baton->ptemp;
request_rec *r;
wctx_t *wctx;
hc_condition_t *cond;
apr_bucket_brigade *bb;
wctx = (wctx_t *)hc->context;
if (!wctx->req || !wctx->method) {
return APR_ENOTIMPL;
}
if ((status = hc_get_backend("HCOH", &backend, hc, ctx, ptemp)) != OK) {
return backend_cleanup("HCOH", backend, ctx->s, status);
}
if ((status = ap_proxy_connect_backend("HCOH", backend, hc, ctx->s)) != OK) {
return backend_cleanup("HCOH", backend, ctx->s, status);
}
r = create_request_rec(ptemp, ctx->s, baton->balancer, wctx->method);
if ((status = ap_proxy_connection_create_ex("HCOH", backend, r)) != OK) {
return backend_cleanup("HCOH", backend, ctx->s, status);
}
set_request_connection(r, backend->connection);
bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
if ((status = hc_send(r, wctx->req, bb)) != OK) {
return backend_cleanup("HCOH", backend, ctx->s, status);
}
if ((status = hc_read_headers(r)) != OK) {
return backend_cleanup("HCOH", backend, ctx->s, status);
}
if (!r->header_only) {
apr_table_t *saved_headers_in = r->headers_in;
r->headers_in = apr_table_copy(r->pool, r->headers_out);
ap_proxy_pre_http_request(backend->connection, r);
status = hc_read_body(r, bb);
r->headers_in = saved_headers_in;
if (status != OK) {
return backend_cleanup("HCOH", backend, ctx->s, status);
}
r->trailers_out = apr_table_copy(r->pool, r->trailers_in);
}
if (*worker->s->hcexpr &&
(cond = (hc_condition_t *)apr_table_get(ctx->conditions, worker->s->hcexpr)) != NULL) {
const char *err;
int ok = ap_expr_exec(r, cond->pexpr, &err);
if (ok > 0) {
ap_log_error(APLOG_MARK, APLOG_TRACE2, 0, ctx->s,
"Condition %s for %s (%s): passed", worker->s->hcexpr,
hc->s->name, worker->s->name);
} else if (ok < 0 || err) {
ap_log_error(APLOG_MARK, APLOG_INFO, 0, ctx->s, APLOGNO(03301)
"Error on checking condition %s for %s (%s): %s", worker->s->hcexpr,
hc->s->name, worker->s->name, err);
status = !OK;
} else {
ap_log_error(APLOG_MARK, APLOG_TRACE2, 0, ctx->s,
"Condition %s for %s (%s) : failed", worker->s->hcexpr,
hc->s->name, worker->s->name);
status = !OK;
}
} else if (r->status < 200 || r->status > 399) {
ap_log_error(APLOG_MARK, APLOG_TRACE2, 0, ctx->s,
"Response status %i for %s (%s): failed", r->status,
hc->s->name, worker->s->name);
status = !OK;
}
return backend_cleanup("HCOH", backend, ctx->s, status);
}
static void * APR_THREAD_FUNC hc_check(apr_thread_t *thread, void *b)
{
baton_t *baton = (baton_t *)b;
server_rec *s = baton->ctx->s;
proxy_worker *worker = baton->worker;
proxy_worker *hc = baton->hc;
apr_time_t now = baton->now;
apr_status_t rv;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(03256)
"%sHealth checking %s", (thread ? "Threaded " : ""),
worker->s->name);
worker->s->updated = now;
if (hc->s->method == TCP) {
rv = hc_check_tcp(baton);
}
else {
rv = hc_check_http(baton);
}
if (rv == APR_ENOTIMPL) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(03257)
"Somehow tried to use unimplemented hcheck method: %d",
(int)hc->s->method);
apr_pool_destroy(baton->ptemp);
return NULL;
}
/* what state are we in ? */
if (PROXY_WORKER_IS_HCFAILED(worker)) {
if (rv == APR_SUCCESS) {
worker->s->pcount += 1;
if (worker->s->pcount >= worker->s->passes) {
ap_proxy_set_wstatus(PROXY_WORKER_HC_FAIL_FLAG, 0, worker);
ap_proxy_set_wstatus(PROXY_WORKER_IN_ERROR_FLAG, 0, worker);
worker->s->pcount = 0;
ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(03302)
"%sHealth check ENABLING %s", (thread ? "Threaded " : ""),
worker->s->name);
}
}
} else {
if (rv != APR_SUCCESS) {
worker->s->error_time = now;
worker->s->fcount += 1;
if (worker->s->fcount >= worker->s->fails) {
ap_proxy_set_wstatus(PROXY_WORKER_HC_FAIL_FLAG, 1, worker);
worker->s->fcount = 0;
ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(03303)
"%sHealth check DISABLING %s", (thread ? "Threaded " : ""),
worker->s->name);
}
}
}
apr_pool_destroy(baton->ptemp);
return NULL;
}
static apr_status_t hc_watchdog_callback(int state, void *data,
apr_pool_t *pool)
{
apr_status_t rv = APR_SUCCESS;
apr_time_t now = apr_time_now();
proxy_balancer *balancer;
sctx_t *ctx = (sctx_t *)data;
server_rec *s = ctx->s;
proxy_server_conf *conf;
static apr_thread_pool_t *hctp = NULL;
switch (state) {
case AP_WATCHDOG_STATE_STARTING:
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(03258)
"%s watchdog started.",
HCHECK_WATHCHDOG_NAME);
#if HC_USE_THREADS
if (tpsize && hctp == NULL) {
rv = apr_thread_pool_create(&hctp, tpsize,
tpsize, ctx->p);
if (rv != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_INFO, rv, s, APLOGNO(03312)
"apr_thread_pool_create() with %d threads failed",
tpsize);
/* we can continue on without the threadpools */
hctp = NULL;
} else {
ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, s, APLOGNO(03313)
"apr_thread_pool_create() with %d threads succeeded",
tpsize);
}
} else {
ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, s, APLOGNO(03314)
"Skipping apr_thread_pool_create()");
hctp = NULL;
}
#endif
break;
case AP_WATCHDOG_STATE_RUNNING:
/* loop thru all workers */
ap_log_error(APLOG_MARK, APLOG_TRACE5, 0, s,
"Run of %s watchdog.",
HCHECK_WATHCHDOG_NAME);
if (s) {
int i;
conf = (proxy_server_conf *) ap_get_module_config(s->module_config, &proxy_module);
balancer = (proxy_balancer *)conf->balancers->elts;
ctx->s = s;
for (i = 0; i < conf->balancers->nelts; i++, balancer++) {
int n;
proxy_worker **workers;
proxy_worker *worker;
/* Have any new balancers or workers been added dynamically? */
ap_proxy_sync_balancer(balancer, s, conf);
workers = (proxy_worker **)balancer->workers->elts;
for (n = 0; n < balancer->workers->nelts; n++) {
worker = *workers;
if (!PROXY_WORKER_IS(worker, PROXY_WORKER_STOPPED) &&
(worker->s->method != NONE) &&
(now > worker->s->updated + worker->s->interval)) {
baton_t *baton;
apr_pool_t *ptemp;
ap_log_error(APLOG_MARK, APLOG_TRACE3, 0, s,
"Checking %s worker: %s [%d] (%pp)", balancer->s->name,
worker->s->name, worker->s->method, worker);
if ((rv = hc_init_worker(ctx, worker)) != APR_SUCCESS) {
return rv;
}
/* This pool must last the lifetime of the (possible) thread */
apr_pool_create(&ptemp, ctx->p);
apr_pool_tag(ptemp, "hc_request");
baton = apr_palloc(ptemp, sizeof(baton_t));
baton->ctx = ctx;
baton->now = now;
baton->balancer = balancer;
baton->worker = worker;
baton->ptemp = ptemp;
baton->hc = hc_get_hcworker(ctx, worker, ptemp);
if (!hctp) {
hc_check(NULL, baton);
}
#if HC_USE_THREADS
else {
rv = apr_thread_pool_push(hctp, hc_check, (void *)baton,
APR_THREAD_TASK_PRIORITY_NORMAL, NULL);
}
#endif
}
workers++;
}
}
}
break;
case AP_WATCHDOG_STATE_STOPPING:
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(03261)
"stopping %s watchdog.",
HCHECK_WATHCHDOG_NAME);
#if HC_USE_THREADS
if (hctp) {
rv = apr_thread_pool_destroy(hctp);
if (rv != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_INFO, rv, s, APLOGNO(03315)
"apr_thread_pool_destroy() failed");
}
}
#endif
hctp = NULL;
break;
}
return rv;
}
static int hc_pre_config(apr_pool_t *pconf, apr_pool_t *plog,
apr_pool_t *ptemp)
{
tpsize = HC_THREADPOOL_SIZE;
return OK;
}
static int hc_post_config(apr_pool_t *p, apr_pool_t *plog,
apr_pool_t *ptemp, server_rec *main_s)
{
apr_status_t rv;
server_rec *s = main_s;
APR_OPTIONAL_FN_TYPE(ap_watchdog_get_instance) *hc_watchdog_get_instance;
APR_OPTIONAL_FN_TYPE(ap_watchdog_register_callback) *hc_watchdog_register_callback;
if (ap_state_query(AP_SQ_MAIN_STATE) == AP_SQ_MS_CREATE_PRE_CONFIG) {
return OK;
}
hc_watchdog_get_instance = APR_RETRIEVE_OPTIONAL_FN(ap_watchdog_get_instance);
hc_watchdog_register_callback = APR_RETRIEVE_OPTIONAL_FN(ap_watchdog_register_callback);
if (!hc_watchdog_get_instance || !hc_watchdog_register_callback) {
ap_log_error(APLOG_MARK, APLOG_CRIT, 0, s, APLOGNO(03262)
"mod_watchdog is required");
return !OK;
}
rv = hc_watchdog_get_instance(&watchdog,
HCHECK_WATHCHDOG_NAME,
0, 1, p);
if (rv) {
ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(03263)
"Failed to create watchdog instance (%s)",
HCHECK_WATHCHDOG_NAME);
return !OK;
}
while (s) {
sctx_t *ctx = ap_get_module_config(s->module_config,
&proxy_hcheck_module);
if (s != ctx->s) {
ap_log_error(APLOG_MARK, APLOG_TRACE4, 0, s, APLOGNO(10019)
"Missing unique per-server context: %s (%pp:%pp) (no hchecks)",
s->server_hostname, s, ctx->s);
s = s->next;
continue;
}
rv = hc_watchdog_register_callback(watchdog,
AP_WD_TM_SLICE,
ctx,
hc_watchdog_callback);
if (rv) {
ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(03264)
"Failed to register watchdog callback (%s)",
HCHECK_WATHCHDOG_NAME);
return !OK;
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(03265)
"watchdog callback registered (%s for %s)", HCHECK_WATHCHDOG_NAME, s->server_hostname);
s = s->next;
}
return OK;
}
static void hc_show_exprs(request_rec *r)
{
const apr_table_entry_t *elts;
const apr_array_header_t *hdr;
int i;
sctx_t *ctx = (sctx_t *) ap_get_module_config(r->server->module_config,
&proxy_hcheck_module);
if (apr_is_empty_table(ctx->conditions))
return;
ap_rputs("\n\n<table>"
"<tr><th colspan='2'>Health check cond. expressions:</th></tr>\n"
"<tr><th>Expr name</th><th>Expression</th></tr>\n", r);
hdr = apr_table_elts(ctx->conditions);
elts = (const apr_table_entry_t *) hdr->elts;
for (i = 0; i < hdr->nelts; ++i) {
hc_condition_t *cond;
if (!elts[i].key) {
continue;
}
cond = (hc_condition_t *)elts[i].val;
ap_rprintf(r, "<tr><td>%s</td><td>%s</td></tr>\n",
ap_escape_html(r->pool, elts[i].key),
ap_escape_html(r->pool, cond->expr));
}
ap_rputs("</table><hr/>\n", r);
}
static void hc_select_exprs(request_rec *r, const char *expr)
{
const apr_table_entry_t *elts;
const apr_array_header_t *hdr;
int i;
sctx_t *ctx = (sctx_t *) ap_get_module_config(r->server->module_config,
&proxy_hcheck_module);
if (apr_is_empty_table(ctx->conditions))
return;
hdr = apr_table_elts(ctx->conditions);
elts = (const apr_table_entry_t *) hdr->elts;
for (i = 0; i < hdr->nelts; ++i) {
if (!elts[i].key) {
continue;
}
ap_rprintf(r, "<option value='%s' %s >%s</option>\n",
ap_escape_html(r->pool, elts[i].key),
(!strcmp(elts[i].key, expr)) ? "selected" : "",
ap_escape_html(r->pool, elts[i].key));
}
}
static int hc_valid_expr(request_rec *r, const char *expr)
{
const apr_table_entry_t *elts;
const apr_array_header_t *hdr;
int i;
sctx_t *ctx = (sctx_t *) ap_get_module_config(r->server->module_config,
&proxy_hcheck_module);
if (apr_is_empty_table(ctx->conditions))
return 0;
hdr = apr_table_elts(ctx->conditions);
elts = (const apr_table_entry_t *) hdr->elts;
for (i = 0; i < hdr->nelts; ++i) {
if (!elts[i].key) {
continue;
}
if (!strcmp(elts[i].key, expr))
return 1;
}
return 0;
}
static const char *hc_get_body(request_rec *r)
{
apr_off_t length;
apr_size_t len;
apr_status_t rv;
char *buf;
if (!r || !r->kept_body)
return "";
rv = apr_brigade_length(r->kept_body, 1, &length);
len = (apr_size_t)length;
if (rv != APR_SUCCESS || len == 0)
return "";
buf = apr_palloc(r->pool, len + 1);
rv = apr_brigade_flatten(r->kept_body, buf, &len);
if (rv != APR_SUCCESS)
return "";
buf[len] = '\0'; /* ensure */
return (const char*)buf;
}
static const char *hc_expr_var_fn(ap_expr_eval_ctx_t *ctx, const void *data)
{
char *var = (char *)data;
if (var && *var && ctx->r && ap_cstr_casecmp(var, "BODY") == 0) {
return hc_get_body(ctx->r);
}
return NULL;
}
static const char *hc_expr_func_fn(ap_expr_eval_ctx_t *ctx, const void *data,
const char *arg)
{
char *var = (char *)arg;
if (var && *var && ctx->r && ap_cstr_casecmp(var, "BODY") == 0) {
return hc_get_body(ctx->r);
}
return NULL;
}
static int hc_expr_lookup(ap_expr_lookup_parms *parms)
{
switch (parms->type) {
case AP_EXPR_FUNC_VAR:
/* for now, we just handle everything that starts with HC_.
*/
if (strncasecmp(parms->name, "HC_", 3) == 0) {
*parms->func = hc_expr_var_fn;
*parms->data = parms->name + 3;
return OK;
}
break;
case AP_EXPR_FUNC_STRING:
/* Function HC() is implemented by us.
*/
if (strcasecmp(parms->name, "HC") == 0) {
*parms->func = hc_expr_func_fn;
*parms->data = parms->arg;
return OK;
}
break;
}
return DECLINED;
}
static const command_rec command_table[] = {
AP_INIT_RAW_ARGS("ProxyHCTemplate", set_hc_template, NULL, OR_FILEINFO,
"Health check template"),
AP_INIT_RAW_ARGS("ProxyHCExpr", set_hc_condition, NULL, OR_FILEINFO,
"Define a health check condition ruleset expression"),
#if HC_USE_THREADS
AP_INIT_TAKE1("ProxyHCTPsize", set_hc_tpsize, NULL, RSRC_CONF,
"Set size of health check thread pool"),
#endif
{ NULL }
};
static void hc_register_hooks(apr_pool_t *p)
{
static const char *const aszPre[] = { "mod_proxy_balancer.c", "mod_proxy.c", NULL};
static const char *const aszSucc[] = { "mod_watchdog.c", NULL};
APR_REGISTER_OPTIONAL_FN(set_worker_hc_param);
APR_REGISTER_OPTIONAL_FN(hc_show_exprs);
APR_REGISTER_OPTIONAL_FN(hc_select_exprs);
APR_REGISTER_OPTIONAL_FN(hc_valid_expr);
ap_hook_pre_config(hc_pre_config, NULL, NULL, APR_HOOK_MIDDLE);
ap_hook_post_config(hc_post_config, aszPre, aszSucc, APR_HOOK_LAST);
ap_hook_expr_lookup(hc_expr_lookup, NULL, NULL, APR_HOOK_MIDDLE);
}
/* the main config structure */
AP_DECLARE_MODULE(proxy_hcheck) =
{
STANDARD20_MODULE_STUFF,
NULL, /* create per-dir config structures */
NULL, /* merge per-dir config structures */
hc_create_config, /* create per-server config structures */
NULL, /* merge per-server config structures */
command_table, /* table of config file commands */
hc_register_hooks /* register hooks */
};