Memory Leak Testing

Makefile

@@ -10,6 +10,7 @@ TEST_OBJS := $(notdir $(patsubst %.c,%.o, $(wildcard $(TESTS_DIR)/*.c)))
 
 CC := gcc
 CFLAGS := -Wall -Wextra -pedantic -Werror
+CFLAGSTEST := -Wall -Wextra -pedantic -Werror -fsanitize=address -g
 LDFLAGS := -lpcap -lpthread
 
 $(NAME): dir $(OBJS)
@@ -19,13 +20,21 @@ $(OBJS):
 	@$(CC) $(CFLAGS) -o $(BUILD_DIR)/$@ -c $(SRC_DIR)/$*.c
 
 test: dir $(TEST_OBJS) $(OBJS)
-	@$(CC) $(CFLAGS) -o $(TESTS_DIR)/$(BIN_DIR)/run_all_tests \
+	@$(CC) $(CFLAGSTEST) -o $(TESTS_DIR)/$(BIN_DIR)/run_all_tests \
 	$(patsubst %,$(BUILD_DIR)/%, $(filter-out main.o, $(OBJS))) \
 	$(patsubst %,$(TESTS_DIR)/$(BUILD_DIR)/%, $(TEST_OBJS)) $(LDFLAGS)
 	@sudo $(TESTS_DIR)/$(BIN_DIR)/run_all_tests
-
+	@echo "\n-- SEPARATE LEAK TESTS --"
+	@$(MAKE) leaks
+
 $(TEST_OBJS):
-	@$(CC) $(CFLAGS) -o $(TESTS_DIR)/$(BUILD_DIR)/$@ -c $(TESTS_DIR)/$*.c
+	@$(CC) $(CFLAGSTEST) -o $(TESTS_DIR)/$(BUILD_DIR)/$@ -c $(TESTS_DIR)/$*.c
+
+leaks: CFLAGS := $(CFLAGSTEST)
+leaks: clean dir $(NAME)
+	@sudo chmod +x $(TESTS_DIR)/leaks.sh
+	@sudo $(TESTS_DIR)/leaks.sh
+	@$(MAKE) clean
 
 dir:
 	@mkdir -p $(BIN_DIR) $(BUILD_DIR) $(TESTS_DIR)/$(BIN_DIR) \
@@ -35,4 +44,4 @@ clean:
 	@rm -rf $(BUILD_DIR) $(BIN_DIR) $(TESTS_DIR)/$(BIN_DIR) \
 	$(TESTS_DIR)/$(BUILD_DIR)
 
-.PHONY: dir test clean
+.PHONY: dir test clean leaks

README.md

@@ -15,10 +15,14 @@ Disco is a cross-platform network utility available on Linux and macOS. It suppo
 - [Usage](#usage)
    - [Examples](#examples)
 - [Testing](#testing)
+   - [Integration Tests](#integration-tests)
+   - [Memory Leak Tests](#memory-leak-tests)
 - [Technical Details](#technical-details)
    - [Address Resolution Protocol (ARP)](#address-resolution-protocol-arp)
    - [ICMP Echo Request (Ping)](#icmp-echo-request-ping)
    - [TCP SYN Scanning](#tcp-syn-scanning)
+   - [OS Fingerprinting](#os-fingerprinting)
+   - [Network Diagnostics](#network-diagnostics)
 
 ## Installation
 1. Clone the repository
@@ -69,7 +73,7 @@ disco - network utility for host discovery and port enumeration
 author: pilsnerfrajz
 
 usage: disco target [-h] [-p ports] [-o] [-n] [-P] [-a] [-S]
-                    [-w file] [-f]
+					[-w file] [-f]
 options:
   target          : host to scan (IP address or domain)
   -p, --ports     : ports to scan, e.g., -p 1-1024 or -p 21,22,80
@@ -98,6 +102,8 @@ sudo ./bin/disco 127.0.0.1 -n -p 1-65535
 ```
 
 ## Testing
+
+### Integration Tests
 The program includes comprehensive **integration tests** that validate real network functionality. Run with `make test` from the project root to test:
 - ARP 
 	- Requests to LAN devices 
@@ -111,13 +117,14 @@ The program includes comprehensive **integration tests** that validate real netw
 	- Port scan of IPv4/IPv6 localhost
 	- Port scan of LAN device
 	- Port scan of IPv4/IPv6 external hosts
-- CLI
-	- Setting all available CLI arguments
-	- Printing of usage message with `-h` flag
+- OS Fingerprinting
+	- Windows, Linux and BSD-like (e.g. macOS) systems
+- Memory leaks (see Section [Memory Leak Tests](#memory-leak-tests))
 
 Some tests may fail due to hardcoded IP addresses and port numbers not accessible or open on the targets in your network. Test cases that involve localhost or domains should still pass however. 
 
-The future plan is to implement these tests in a CI pipeline using Docker to ensure working features, regardless of device and network configurations. 
+### Memory Leak Tests
+Memory leak tests are included to ensure proper memory management. These tests utilize the `AddressSanitizer` available in `clang`. Run with `make leaks` from the project root to execute leak tests with various argument combinations. Each test will report if any memory leaks were detected.
 
 ## Technical Details
 Disco is implemented in C using `libpcap` for frame injection and packet filtering. This section describes the implementation of ARP, ping and port scanning in more detail for those interested.

src/arp.c

@@ -183,6 +183,9 @@ int arp(char *address)
 		return PCAP_OPEN;
 	}
 
+	/* Free memory */
+	free(if_name);
+
 	if (pcap_inject(handle, &arp_frame, sizeof(arp_frame)) < 0)
 	{
 		pcap_close(handle);
@@ -210,6 +213,9 @@ int arp(char *address)
 		return PCAP_FILTER;
 	}
 
+	/* Free filter malloc */
+	pcap_freecode(&filter);
+
 	struct callback_data c_data = {0};
 	memcpy(&c_data.arp_frame, &arp_frame, sizeof(c_data.arp_frame));
 	c_data.reply_found = 0;

src/ping.c

@@ -283,8 +283,7 @@ int ping(char *address, int tries)
 			free(reply_hdr);
 		}
 	}
-
-	if (dst->ai_family == AF_INET6)
+	else if (dst->ai_family == AF_INET6)
 	{
 		for (int attempt = 0; attempt < tries; attempt++)
 		{

src/syn_scan.c

@@ -731,6 +731,10 @@ static int pcap_filter_setup(char *address, struct src_info src_info)
 	{
 		return PCAP_FILTER;
 	}
+
+	/* Free filter malloc */
+	pcap_freecode(&filter);
+
 	return 0;
 }
 

src/utils.c

@@ -74,13 +74,16 @@ struct addrinfo *get_dst_addr_struct(char *dst, int sock_type)
 		return NULL;
 	}
 
-	res->ai_addr = malloc(sizeof(struct addrinfo));
+	/* Clear struct in case there is garbage */
+	memset(res, 0, sizeof(struct addrinfo));
+
+	res->ai_addr = malloc(temp->ai_addrlen);
 	if (res->ai_addr == NULL)
 	{
 		freeaddrinfo(dst_info);
 		return NULL;
 	}
-	memcpy(res->ai_addr, temp->ai_addr, sizeof(struct addrinfo));
+	memcpy(res->ai_addr, temp->ai_addr, temp->ai_addrlen);
 	res->ai_family = temp->ai_family;
 	res->ai_addrlen = temp->ai_addrlen;
 

tests/fingerprint_test.c

@@ -9,7 +9,7 @@
 
 void fingerprint_tests(void)
 {
-	printf("-- Fingerprint Tests --\n");
+	printf("-- FINGERPRINT TESTS --\n");
 
 	set_test_print_flag(0);
 

tests/leaks.sh

@@ -0,0 +1,72 @@
+#!/bin/bash
+
+BIN="./bin/disco"
+
+run_test() {
+	ERR_LOG=$(mktemp)
+
+	# run binary with argument
+	$BIN "$@" > /dev/null 2> "$ERR_LOG"
+	if grep -q "Sanitizer" "$ERR_LOG"; then
+		echo "❌ Leak test with arguments '$@': failed"
+		cat "$ERR_LOG"
+		exit 1
+	else
+		echo "✅ Leak test with arguments '$@': passed"
+	fi
+	rm -f "$ERR_LOG"
+}
+
+run_test "-h"
+run_test --help
+run_test
+
+run_test localhost -P
+run_test localhost --ping-only
+run_test localhost -a
+run_test localhost --arp-only
+run_test localhost -S
+run_test localhost --syn-only
+run_test localhost -n
+
+run_test localhost -p 80
+run_test localhost -p 22,80,443
+run_test localhost -p 1-100
+run_test localhost -p 1-5,80,8080-8090
+
+run_test localhost -p 0
+run_test localhost -p 70000
+run_test localhost -p 80,,22
+run_test 0.0.0.0 -P
+run_test 255.255.255.255 -P
+
+run_test localhost -P -w out.txt
+rm -f out.txt
+
+run_test localhost -p 80 -o -f
+run_test localhost -n -p 22,80 -w out.txt
+rm -f out.txt
+
+run_test 192.168.1.1 -P
+run_test 192.168.1.1 --ping-only
+run_test 192.168.1.1 -a
+run_test 192.168.1.1 --arp-only
+run_test 192.168.1.1 -S
+run_test 192.168.1.1 --syn-only
+run_test 192.168.1.1 -n
+
+run_test 192.168.1.1 -p 80
+run_test 192.168.1.1 -p 22,80,443
+run_test 192.168.1.1 -p 1-100
+run_test 192.168.1.1 -p 1-5,80,8080-8090
+
+run_test 192.168.1.1 -p 0
+run_test 192.168.1.1 -p 70000
+run_test 192.168.1.1 -p 80,,22
+
+run_test 192.168.1.1 -P -w out.txt
+rm -f out.txt
+
+run_test 192.168.1.1 -p 80 -o -f
+run_test 192.168.1.1 -n -p 22,80 -w out.txt
+rm -f out.txt