Added more unit tests, test coverage reports

Makefile

@@ -65,9 +65,11 @@ TAP_PIE_OBJ:=$(patsubst src/%.c,build/pie/%.o,$(TAP_SRC))
 ifeq ($(UNAME_S),Darwin)
   BEGIN_GROUP:=
   END_GROUP:=
+  OPEN_CMD?=open
 else
   BEGIN_GROUP:=-Wl,--start-group
   END_GROUP:=-Wl,--end-group
+  OPEN_CMD?=xdg-open
 endif
 
 CHECK_PKG_CFLAGS:=$(shell pkg-config --cflags check 2>/dev/null)
@@ -76,6 +78,7 @@ CHECK_PKG_LIBS:=$(shell pkg-config --libs check 2>/dev/null)
 ifneq ($(CHECK_PKG_CFLAGS),)
   UNIT_CFLAGS+=$(CHECK_PKG_CFLAGS)
 endif
+UNIT_CFLAGS+=-Isrc/test/unit/mocks
 
 CPPCHECK=cppcheck
 CPPCHECK_FLAGS=--enable=warning,performance,portability,missingInclude \
@@ -271,17 +274,40 @@ unit: build/test/unit
 build/test/unit:
 	@mkdir -p build/test/
 	@echo "[CC] unit.c"
-	@$(CC) $(CFLAGS) $(UNIT_CFLAGS) -c src/test/unit/unit.c -o build/test/unit.o
+	@$(CC) $(UNIT_CFLAGS) $(CFLAGS) -c src/test/unit/unit.c -o build/test/unit.o
 	@echo "[LD] $@"
 	@$(CC) build/test/unit.o -o build/test/unit $(UNIT_LDFLAGS) $(LDFLAGS)
 
+COV_DIR:=build/coverage
+COV_UNIT:=$(COV_DIR)/unit
+COV_UNIT_O:=$(COV_DIR)/unit.o
+
+$(COV_UNIT_O): src/test/unit/unit.c
+	@mkdir -p $(COV_DIR)
+	@echo "[CC] unit.c (coverage)"
+	@$(CC) $(UNIT_CFLAGS) $(CFLAGS) --coverage -c src/test/unit/unit.c -o $(COV_UNIT_O)
+
+$(COV_UNIT): LDFLAGS+=--coverage $(UNIT_LIBS)
+$(COV_UNIT): $(COV_UNIT_O)
+	@echo "[LD] $@"
+	@$(CC) $(COV_UNIT_O) -o $(COV_UNIT) $(UNIT_LDFLAGS) $(LDFLAGS)
+
+cov: unit $(COV_UNIT)
+	@echo "[RUN] unit (coverage)"
+	@rm -f $(COV_DIR)/*.gcda
+	@$(COV_UNIT)
+	@echo "[COV] gcovr html"
+	@mkdir -p build/coverage
+	@gcovr -r . --exclude "src/test/unit/unit.c" --html-details -o build/coverage/index.html
+	@$(OPEN_CMD) build/coverage/index.html
+
 # Install dynamic library to re-link linux applications
 #
 install:
 	install libwolfip.so $(PREFIX)/lib
 	ldconfig
 
-.PHONY: clean all static cppcheck
+.PHONY: clean all static cppcheck cov
 
 cppcheck:
 	$(CPPCHECK) $(CPPCHECK_FLAGS) src/ 2>cppcheck_results.xml

README.md

@@ -13,19 +13,38 @@ A single network interface can be associated with the device.
 
 ## Features supported
 
-- ARP (RFC 826)
-- IPv4 (RFC 791)
-- ICMP (RFC 792): only ping replies
-- DHCP (RFC 2131): client only
-- DNS  (RFC 1035): client only
-- UDP (RFC 768): unicast only
-- TCP (RFC 793) 
-  - TCP options supported: Timestamps, Maximum Segment Size
 - BSD-like, non blocking socket API, with custom callbacks
 - No dynamic memory allocation
   - Fixed number of concurrent sockets
   - Pre-allocated buffers for packet processing in static memory
 
+## Protocols and RFCs
+
+| Layer | Protocol | Features | RFC(s) |
+|-------|----------|----------|--------|
+| **Data Link** | Ethernet II | Frame encapsulation | [IEEE 802.3](https://standards.ieee.org/ieee/802.3/10422/) |
+| **Data Link** | ARP | Address resolution, request/reply | [RFC 826](https://datatracker.ietf.org/doc/html/rfc826) |
+| **Network** | IPv4 | Datagram delivery, TTL handling | [RFC 791](https://datatracker.ietf.org/doc/html/rfc791) |
+| **Network** | IPv4 Forwarding | Multi-interface routing (optional) | [RFC 1812](https://datatracker.ietf.org/doc/html/rfc1812) |
+| **Network** | ICMP | Echo request/reply, TTL exceeded | [RFC 792](https://datatracker.ietf.org/doc/html/rfc792) |
+| **Transport** | UDP | Unicast datagrams, checksum | [RFC 768](https://datatracker.ietf.org/doc/html/rfc768) |
+| **Transport** | TCP | Connection management, reliable delivery | [RFC 793](https://datatracker.ietf.org/doc/html/rfc793), [RFC 9293](https://datatracker.ietf.org/doc/html/rfc9293) |
+| **Transport** | TCP Options: MSS | Maximum Segment Size negotiation | [RFC 793](https://datatracker.ietf.org/doc/html/rfc793) |
+| **Transport** | TCP Options: Timestamps | RTT measurement, PAWS | [RFC 7323](https://datatracker.ietf.org/doc/html/rfc7323) |
+| **Transport** | TCP Congestion Control | Slow start, congestion avoidance | [RFC 5681](https://datatracker.ietf.org/doc/html/rfc5681) |
+| **Transport** | TCP Fast Retransmit | Triple duplicate ACK detection | [RFC 5681](https://datatracker.ietf.org/doc/html/rfc5681) |
+| **Application** | DHCP | Client only (DORA) | [RFC 2131](https://datatracker.ietf.org/doc/html/rfc2131) |
+| **Application** | DNS | A and PTR record queries (client) | [RFC 1035](https://datatracker.ietf.org/doc/html/rfc1035) |
+| **Application** | HTTP/HTTPS | Server with wolfSSL TLS support | [RFC 9110](https://datatracker.ietf.org/doc/html/rfc9110) |
+
+### Notes
+
+- **TCP Congestion Control**: Implements slow start and congestion avoidance with `cwnd`, `ssthresh` tracking.
+- **TCP Fast Retransmit**: Detects triple duplicate ACKs and retransmits lost segments.
+- **ICMP**: Responds to ping requests; sends TTL exceeded messages when forwarding is enabled.
+- **DHCP**: Full DORA (Discover, Offer, Request, Acknowledge) state machine with retry logic.
+- **DNS**: Supports A record (forward) and PTR record (reverse) lookups.
+
 
 ## Functional tests with `LD_PRELOAD`
 

src/port/wolfssl_io.c

@@ -25,7 +25,6 @@
 #include <wolfssl/ssl.h>
 #include <wolfssl/wolfcrypt/memory.h>
 
-
 #ifndef MAX_WOLFIP_CTX
     #define MAX_WOLFIP_CTX 8 /* Default value */
 #endif

src/test/unit/mocks/wolfssl/ssl.h

@@ -0,0 +1,39 @@
+/* Mock wolfssl/ssl.h for unit tests.
+ * Only includes pieces needed by src/port/wolfssl_io.c tests.
+ */
+#ifndef WOLFSSL_SSL_H
+#define WOLFSSL_SSL_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct WOLFSSL_CTX {
+    int id;
+} WOLFSSL_CTX;
+
+typedef struct WOLFSSL {
+    WOLFSSL_CTX *ctx;
+    void *rctx;
+    void *wctx;
+} WOLFSSL;
+
+typedef int (*CallbackIORecv)(WOLFSSL *ssl, char *buf, int sz, void *ctx);
+typedef int (*CallbackIOSend)(WOLFSSL *ssl, char *buf, int sz, void *ctx);
+
+#define WOLFSSL_CBIO_ERR_GENERAL    (-1)
+#define WOLFSSL_CBIO_ERR_WANT_READ  (-2)
+#define WOLFSSL_CBIO_ERR_WANT_WRITE (-2)
+#define WOLFSSL_CBIO_ERR_CONN_CLOSE (-5)
+
+int wolfSSL_SetIORecv(WOLFSSL_CTX *ctx, CallbackIORecv cb);
+int wolfSSL_SetIOSend(WOLFSSL_CTX *ctx, CallbackIOSend cb);
+int wolfSSL_SetIOReadCtx(WOLFSSL *ssl, void *ctx);
+int wolfSSL_SetIOWriteCtx(WOLFSSL *ssl, void *ctx);
+WOLFSSL_CTX *wolfSSL_get_SSL_CTX(WOLFSSL *ssl);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* WOLFSSL_SSL_H */

src/test/unit/mocks/wolfssl/wolfcrypt/memory.h

@@ -0,0 +1,5 @@
+/* Mock wolfssl/wolfcrypt/memory.h for unit tests. */
+#ifndef WOLFSSL_WOLFCRYPT_MEMORY_H
+#define WOLFSSL_WOLFCRYPT_MEMORY_H
+
+#endif /* WOLFSSL_WOLFCRYPT_MEMORY_H */

src/test/unit/mocks/wolfssl/wolfcrypt/settings.h

@@ -0,0 +1,5 @@
+/* Mock wolfssl/wolfcrypt/settings.h for unit tests. */
+#ifndef WOLFSSL_WOLFCRYPT_SETTINGS_H
+#define WOLFSSL_WOLFCRYPT_SETTINGS_H
+
+#endif /* WOLFSSL_WOLFCRYPT_SETTINGS_H */