From dd8be1fcb11089b22ab5eb7332d5640b4cae80b0 Mon Sep 17 00:00:00 2001
From: Ivan Nardi <12729895+IvanNardi@users.noreply.github.com>
Date: Fri, 12 Jan 2024 13:30:43 +0100
Subject: Fix some warnings reported by CODESonar (#2227)

Remove some unreached/duplicated code.

Add error checking for `atoi()` calls.

About `isdigit()` and similar functions. The warning reported is:
```
Negative Character Value help
isdigit() is invoked here with an argument of signed type char, but only
has defined behavior for int arguments that are either representable
as unsigned char or equal to the value of macro EOF(-1).
Casting the argument to unsigned char will avoid the undefined behavior.
In a number of libc implementations, isdigit() is implemented using lookup
tables (arrays): passing in a negative value can result in a read underrun.
```
Switching to our macros fix that.
Add a check to `check_symbols.sh` to avoid using the original functions
from libc.
---
 src/lib/protocols/mqtt.c | 6 ------
 1 file changed, 6 deletions(-)

(limited to 'src/lib/protocols/mqtt.c')

diff --git a/src/lib/protocols/mqtt.c b/src/lib/protocols/mqtt.c
index b6eff8c4c..c88844a09 100644
--- a/src/lib/protocols/mqtt.c
+++ b/src/lib/protocols/mqtt.c
@@ -180,18 +180,12 @@ static void ndpi_search_mqtt(struct ndpi_detection_module_struct *ndpi_struct,
 	if (pt == PUBLISH) {
 		// payload CAN be zero bytes length (section 3.3.3 of MQTT standard)
 		u_int8_t qos = (u_int8_t) (flags & 0x06);
-		u_int8_t retain = (u_int8_t) (flags & 0x01);
 		u_int8_t dup = (u_int8_t) (flags & 0x04);
 		if (qos > 2) { // qos values possible are 0,1,2
 			NDPI_LOG_DBG(ndpi_struct, "Excluding Mqtt invalid PUBLISH qos\n");
 			NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_MQTT);
 			return;
 		}
-		if (retain > 1) { // retain flag possible 0,1
-			NDPI_LOG_DBG(ndpi_struct, "Excluding Mqtt invalid PUBLISH retain\n");
-			NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_MQTT);
-			return;
-		}
 		if (dup > 1) { // dup flag possible 0,1
 			NDPI_LOG_DBG(ndpi_struct, "Excluding Mqtt invalid PUBLISH dup\n");
 			NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_MQTT);
-- 
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