static apr_status_t
rate_limit_filter(ap_filter_t *f, apr_bucket_brigade *input_bb)
{
apr_status_t rv = APR_SUCCESS;
rl_ctx_t *ctx = f->ctx;
apr_bucket *fb;
int do_sleep = 0;
apr_bucket_alloc_t *ba = f->r->connection->bucket_alloc;
apr_bucket_brigade *bb = input_bb;
if (f->c->aborted) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, f->r, APLOGNO(01454) "rl: conn aborted");
apr_brigade_cleanup(bb);
return APR_ECONNABORTED;
}
if (ctx == NULL) {
const char *rl = NULL;
int ratelimit;
/* no subrequests. */
if (f->r->main != NULL) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
rl = apr_table_get(f->r->subprocess_env, "rate-limit");
if (rl == NULL) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* rl is in kilo bytes / second */
ratelimit = atoi(rl) * 1024;
if (ratelimit <= 0) {
/* remove ourselves */
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* first run, init stuff */
ctx = apr_palloc(f->r->pool, sizeof(rl_ctx_t));
f->ctx = ctx;
ctx->state = RATE_LIMIT;
ctx->speed = ratelimit;
/* calculate how many bytes / interval we want to send */
/* speed is bytes / second, so, how many (speed / 1000 % interval) */
ctx->chunk_size = (ctx->speed / (1000 / RATE_INTERVAL_MS));
ctx->tmpbb = apr_brigade_create(f->r->pool, ba);
ctx->holdingbb = apr_brigade_create(f->r->pool, ba);
}
while (ctx->state != RATE_ERROR &&
(!APR_BRIGADE_EMPTY(bb) || !APR_BRIGADE_EMPTY(ctx->holdingbb))) {
apr_bucket *e;
if (!APR_BRIGADE_EMPTY(ctx->holdingbb)) {
APR_BRIGADE_CONCAT(bb, ctx->holdingbb);
}
while (ctx->state == RATE_FULLSPEED && !APR_BRIGADE_EMPTY(bb)) {
/* Find where we 'stop' going full speed. */
for (e = APR_BRIGADE_FIRST(bb);
e != APR_BRIGADE_SENTINEL(bb); e = APR_BUCKET_NEXT(e)) {
if (AP_RL_BUCKET_IS_END(e)) {
apr_bucket *f;
f = APR_RING_LAST(&bb->list);
APR_RING_UNSPLICE(e, f, link);
APR_RING_SPLICE_TAIL(&ctx->holdingbb->list, e, f,
apr_bucket, link);
ctx->state = RATE_LIMIT;
break;
}
}
if (f->c->aborted) {
apr_brigade_cleanup(bb);
ctx->state = RATE_ERROR;
break;
}
fb = apr_bucket_flush_create(ba);
APR_BRIGADE_INSERT_TAIL(bb, fb);
rv = ap_pass_brigade(f->next, bb);
if (rv != APR_SUCCESS) {
ctx->state = RATE_ERROR;
ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, f->r, APLOGNO(01455)
"rl: full speed brigade pass failed.");
}
}
while (ctx->state == RATE_LIMIT && !APR_BRIGADE_EMPTY(bb)) {
for (e = APR_BRIGADE_FIRST(bb);
e != APR_BRIGADE_SENTINEL(bb); e = APR_BUCKET_NEXT(e)) {
if (AP_RL_BUCKET_IS_START(e)) {
apr_bucket *f;
f = APR_RING_LAST(&bb->list);
APR_RING_UNSPLICE(e, f, link);
APR_RING_SPLICE_TAIL(&ctx->holdingbb->list, e, f,
apr_bucket, link);
ctx->state = RATE_FULLSPEED;
break;
}
}
while (!APR_BRIGADE_EMPTY(bb)) {
apr_bucket *stop_point;
apr_off_t len = 0;
if (f->c->aborted) {
apr_brigade_cleanup(bb);
ctx->state = RATE_ERROR;
break;
}
if (do_sleep) {
apr_sleep(RATE_INTERVAL_MS * 1000);
}
else {
do_sleep = 1;
}
apr_brigade_length(bb, 1, &len);
rv = apr_brigade_partition(bb, ctx->chunk_size, &stop_point);
if (rv != APR_SUCCESS && rv != APR_INCOMPLETE) {
ctx->state = RATE_ERROR;
ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, f->r, APLOGNO(01456)
"rl: partition failed.");
break;
}
if (stop_point != APR_BRIGADE_SENTINEL(bb)) {
apr_bucket *f;
apr_bucket *e = APR_BUCKET_PREV(stop_point);
f = APR_RING_FIRST(&bb->list);
APR_RING_UNSPLICE(f, e, link);
APR_RING_SPLICE_HEAD(&ctx->tmpbb->list, f, e, apr_bucket,
link);
}
else {
APR_BRIGADE_CONCAT(ctx->tmpbb, bb);
}
fb = apr_bucket_flush_create(ba);
APR_BRIGADE_INSERT_TAIL(ctx->tmpbb, fb);
#if 0
brigade_dump(f->r, ctx->tmpbb);
brigade_dump(f->r, bb);
#endif
rv = ap_pass_brigade(f->next, ctx->tmpbb);
apr_brigade_cleanup(ctx->tmpbb);
if (rv != APR_SUCCESS) {
ctx->state = RATE_ERROR;
ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, f->r, APLOGNO(01457)
"rl: brigade pass failed.");
break;
}
}
}
}
return rv;
}
static apr_status_t
rate_limit_filter(ap_filter_t *f, apr_bucket_brigade *bb)
{
apr_status_t rv = APR_SUCCESS;
rl_ctx_t *ctx = f->ctx;
apr_bucket_alloc_t *ba = f->r->connection->bucket_alloc;
/* Set up our rl_ctx_t on first use */
if (ctx == NULL) {
const char *rl = NULL;
int ratelimit;
int burst = 0;
/* no subrequests. */
if (f->r->main != NULL) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* Configuration: rate limit */
rl = apr_table_get(f->r->subprocess_env, "rate-limit");
if (rl == NULL) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* rl is in kilo bytes / second */
ratelimit = atoi(rl) * 1024;
if (ratelimit <= 0) {
/* remove ourselves */
ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, f->r,
APLOGNO(03488) "rl: disabling: rate-limit = %s (too high?)", rl);
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* Configuration: optional initial burst */
rl = apr_table_get(f->r->subprocess_env, "rate-initial-burst");
if (rl != NULL) {
burst = atoi(rl) * 1024;
if (burst <= 0) {
ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, f->r,
APLOGNO(03489) "rl: disabling burst: rate-initial-burst = %s (too high?)", rl);
burst = 0;
}
}
/* Set up our context */
ctx = apr_palloc(f->r->pool, sizeof(rl_ctx_t));
f->ctx = ctx;
ctx->state = RATE_LIMIT;
ctx->speed = ratelimit;
ctx->burst = burst;
ctx->do_sleep = 0;
/* calculate how many bytes / interval we want to send */
/* speed is bytes / second, so, how many (speed / 1000 % interval) */
ctx->chunk_size = (ctx->speed / (1000 / RATE_INTERVAL_MS));
ctx->tmpbb = apr_brigade_create(f->r->pool, ba);
ctx->holdingbb = apr_brigade_create(f->r->pool, ba);
}
else {
APR_BRIGADE_PREPEND(bb, ctx->holdingbb);
}
while (!APR_BRIGADE_EMPTY(bb)) {
apr_bucket *e;
if (ctx->state == RATE_FULLSPEED) {
/* Find where we 'stop' going full speed. */
for (e = APR_BRIGADE_FIRST(bb);
e != APR_BRIGADE_SENTINEL(bb); e = APR_BUCKET_NEXT(e)) {
if (AP_RL_BUCKET_IS_END(e)) {
apr_brigade_split_ex(bb, e, ctx->holdingbb);
ctx->state = RATE_LIMIT;
break;
}
}
e = apr_bucket_flush_create(ba);
APR_BRIGADE_INSERT_TAIL(bb, e);
rv = ap_pass_brigade(f->next, bb);
apr_brigade_cleanup(bb);
if (rv != APR_SUCCESS) {
ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, f->r, APLOGNO(01455)
"rl: full speed brigade pass failed.");
return rv;
}
}
else {
for (e = APR_BRIGADE_FIRST(bb);
e != APR_BRIGADE_SENTINEL(bb); e = APR_BUCKET_NEXT(e)) {
if (AP_RL_BUCKET_IS_START(e)) {
apr_brigade_split_ex(bb, e, ctx->holdingbb);
ctx->state = RATE_FULLSPEED;
break;
}
}
while (!APR_BRIGADE_EMPTY(bb)) {
apr_off_t len = ctx->chunk_size + ctx->burst;
APR_BRIGADE_CONCAT(ctx->tmpbb, bb);
/*
* Pull next chunk of data; the initial amount is our
* burst allotment (if any) plus a chunk. All subsequent
* iterations are just chunks with whatever remaining
* burst amounts we have left (in case not done in the
* first bucket).
*/
rv = apr_brigade_partition(ctx->tmpbb, len, &e);
if (rv != APR_SUCCESS && rv != APR_INCOMPLETE) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, f->r, APLOGNO(01456)
"rl: partition failed.");
return rv;
}
/* Send next metadata now if any */
while (e != APR_BRIGADE_SENTINEL(ctx->tmpbb)
&& APR_BUCKET_IS_METADATA(e)) {
e = APR_BUCKET_NEXT(e);
}
if (e != APR_BRIGADE_SENTINEL(ctx->tmpbb)) {
apr_brigade_split_ex(ctx->tmpbb, e, bb);
}
else {
apr_brigade_length(ctx->tmpbb, 1, &len);
}
/*
* Adjust the burst amount depending on how much
* we've done up to now.
*/
if (ctx->burst) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, f->r,
APLOGNO(03485) "rl: burst %d; len %"APR_OFF_T_FMT, ctx->burst, len);
if (len < ctx->burst) {
ctx->burst -= len;
}
else {
ctx->burst = 0;
}
}
e = APR_BRIGADE_LAST(ctx->tmpbb);
if (APR_BUCKET_IS_EOS(e)) {
ap_remove_output_filter(f);
}
else if (!APR_BUCKET_IS_FLUSH(e)) {
if (APR_BRIGADE_EMPTY(bb)) {
/* Wait for more (or next call) */
break;
}
e = apr_bucket_flush_create(ba);
APR_BRIGADE_INSERT_TAIL(ctx->tmpbb, e);
}
#if defined(RLFDEBUG)
brigade_dump(f->r, ctx->tmpbb);
brigade_dump(f->r, bb);
#endif /* RLFDEBUG */
if (ctx->do_sleep) {
apr_sleep(RATE_INTERVAL_MS * 1000);
}
else {
ctx->do_sleep = 1;
}
rv = ap_pass_brigade(f->next, ctx->tmpbb);
apr_brigade_cleanup(ctx->tmpbb);
if (rv != APR_SUCCESS) {
/* Most often, user disconnects from stream */
ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, f->r, APLOGNO(01457)
"rl: brigade pass failed.");
return rv;
}
}
}
if (!APR_BRIGADE_EMPTY(ctx->holdingbb)) {
/* Any rate-limited data in tmpbb is sent unlimited along
* with the rest.
*/
APR_BRIGADE_CONCAT(bb, ctx->tmpbb);
APR_BRIGADE_CONCAT(bb, ctx->holdingbb);
}
}
#if defined(RLFDEBUG)
brigade_dump(f->r, ctx->tmpbb);
#endif /* RLFDEBUG */
/* Save remaining tmpbb with the correct lifetime for the next call */
return ap_save_brigade(f, &ctx->holdingbb, &ctx->tmpbb, f->r->pool);
}
