From 1db747da29e661711b8342e6bdc4e0e7a08d4c12 Mon Sep 17 00:00:00 2001
From: Deomid Ryabkov <rojer@cesanta.com>
Date: Thu, 14 Sep 2017 14:45:11 +0100
Subject: [PATCH] Do not double-count recved bytes
Mongoose would report consumed bytes twice if mg_call is invoked recursively (e.g. proto_handler uses mg_call to invoke user's handler).
Reporting twice as much recved as was delivered effectively disables LwIP's TCP throttling and causes buffers to grow too big.
PUBLISHED_FROM=4ad5cd5db4dd54623bd6de2d50d32ddcc9e2b08a
---
mongoose.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/mongoose.c b/mongoose.c
index bb259a68b..4b5603bdd 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -2218,6 +2218,8 @@ MG_INTERNAL void mg_remove_conn(struct mg_connection *conn) {
MG_INTERNAL void mg_call(struct mg_connection *nc,
mg_event_handler_t ev_handler, void *user_data, int ev,
void *ev_data) {
+ static int nesting_level = 0;
+ nesting_level++;
if (ev_handler == NULL) {
/*
* If protocol handler is specified, call it. Otherwise, call user-specified
@@ -2247,7 +2249,10 @@ MG_INTERNAL void mg_call(struct mg_connection *nc,
nc->flags = (flags_before & ~_MG_CALLBACK_MODIFIABLE_FLAGS_MASK) |
(nc->flags & _MG_CALLBACK_MODIFIABLE_FLAGS_MASK);
}
- if (recved > 0 && !(nc->flags & MG_F_UDP)) {
+ /* It's important to not double-count recved bytes, and since mg_call can be
+ * called recursively (e.g. proto_handler invokes user handler), we keep
+ * track of recursion and only report received bytes at the top level. */
+ if (nesting_level == 1 && recved > 0 && !(nc->flags & MG_F_UDP)) {
nc->iface->vtable->recved(nc, recved);
}
}
@@ -2256,6 +2261,7 @@ MG_INTERNAL void mg_call(struct mg_connection *nc,
ev_handler == nc->handler ? "user" : "proto", nc->flags,
(int) nc->recv_mbuf.len, (int) nc->send_mbuf.len));
}
+ nesting_level--;
#if !MG_ENABLE_CALLBACK_USERDATA
(void) user_data;
#endif
@@ -14439,6 +14445,7 @@ static err_t mg_lwip_tcp_recv_cb(void *arg, struct tcp_pcb *tpcb,
struct pbuf *q = p->next;
for (; q != NULL; q = q->next) pbuf_ref(q);
}
+ mgos_lock();
if (cs->rx_chain == NULL) {
cs->rx_offset = 0;
} else if (pbuf_clen(cs->rx_chain) >= 4) {
@@ -14452,6 +14459,7 @@ static err_t mg_lwip_tcp_recv_cb(void *arg, struct tcp_pcb *tpcb,
p = np;
}
}
+ mgos_unlock();
mg_lwip_recv_common(nc, p);
return ERR_OK;
}
@@ -14929,7 +14937,8 @@ void mg_lwip_if_recved(struct mg_connection *nc, size_t len) {
DBG(("%p invalid socket", nc));
return;
}
- DBG(("%p %p %u", nc, cs->pcb.tcp, len));
+ DBG(("%p %p %u %u", nc, cs->pcb.tcp, len,
+ (cs->rx_chain ? cs->rx_chain->tot_len : 0)));
struct tcp_recved_ctx ctx = {.tpcb = cs->pcb.tcp, .len = len};
#if MG_ENABLE_SSL
if (!(nc->flags & MG_F_SSL)) {
--
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