From 08a10a8af5684409c815fea3867512565496a534 Mon Sep 17 00:00:00 2001
From: Deomid Ryabkov <rojer@cesanta.com>
Date: Mon, 10 Apr 2017 18:34:35 +0300
Subject: [PATCH] Handle multiple MQTT messages per RECV event
PUBLISHED_FROM=fc98c51254dd94d3f443fb66e49449da7d9e754c
---
mongoose.c | 30 +++++++++++++++++++-----------
1 file changed, 19 insertions(+), 11 deletions(-)
diff --git a/mongoose.c b/mongoose.c
index fcc508335..32fe0d70d 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -9740,21 +9740,27 @@ static const char *scanto(const char *p, struct mg_str *s) {
MG_INTERNAL int parse_mqtt(struct mbuf *io, struct mg_mqtt_message *mm) {
uint8_t header;
- size_t len = 0;
+ size_t len = 0, len_len = 0;
+ const char *p, *end;
+ unsigned char lc = 0;
int cmd;
- const char *p = &io->buf[1], *end;
if (io->len < 2) return -1;
header = io->buf[0];
cmd = header >> 4;
/* decode mqtt variable length */
- do {
- len += (*p & 127) << 7 * (p - &io->buf[1]);
- } while ((*p++ & 128) != 0 && ((size_t)(p - io->buf) <= io->len));
+ len = len_len = 0;
+ p = io->buf + 1;
+ while ((size_t)(p - io->buf) < io->len) {
+ lc = *((const unsigned char *) p++);
+ len += (lc & 0x7f) << 7 * len_len;
+ len_len++;
+ if (!(lc & 0x80) || (len_len > sizeof(len))) break;
+ }
end = p + len;
- if (end > io->buf + io->len + 1) {
+ if (lc & 0x80 || end > io->buf + io->len) {
return -1;
}
@@ -9829,7 +9835,6 @@ MG_INTERNAL int parse_mqtt(struct mbuf *io, struct mg_mqtt_message *mm) {
static void mqtt_handler(struct mg_connection *nc, int ev,
void *ev_data MG_UD_ARG(void *user_data)) {
- int len;
struct mbuf *io = &nc->recv_mbuf;
struct mg_mqtt_message mm;
memset(&mm, 0, sizeof(mm));
@@ -9838,10 +9843,13 @@ static void mqtt_handler(struct mg_connection *nc, int ev,
switch (ev) {
case MG_EV_RECV:
- len = parse_mqtt(io, &mm);
- if (len == -1) break; /* not fully buffered */
- nc->handler(nc, MG_MQTT_EVENT_BASE + mm.cmd, &mm MG_UD_ARG(user_data));
- mbuf_remove(io, len);
+ /* There can be multiple messages in the buffer, process them all. */
+ while (1) {
+ int len = parse_mqtt(io, &mm);
+ if (len == -1) break; /* not fully buffered */
+ nc->handler(nc, MG_MQTT_EVENT_BASE + mm.cmd, &mm MG_UD_ARG(user_data));
+ mbuf_remove(io, len);
+ }
break;
}
}
--
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