my solution to lab 6

lab/GNUmakefile

@@ -94,6 +94,10 @@ CFLAGS += -Wall -Wno-format -Wno-unused -Werror -gstabs -m32
 # mon_backtrace()'s function prologue on gcc version: (Debian 4.7.2-5) 4.7.2
 CFLAGS += -fno-tree-ch
 
+CFLAGS += -I$(TOP)/net/lwip/include \
+	  -I$(TOP)/net/lwip/include/ipv4 \
+	  -I$(TOP)/net/lwip/jos
+
 # Add -fno-stack-protector if the option exists.
 CFLAGS += $(shell $(CC) -fno-stack-protector -E -x c /dev/null >/dev/null 2>&1 && echo -fno-stack-protector)
 
@@ -142,16 +146,22 @@ include kern/Makefrag
 include lib/Makefrag
 include user/Makefrag
 include fs/Makefrag
+include net/Makefrag
 
 
 CPUS ?= 1
 
+PORT7	:= $(shell expr $(GDBPORT) + 1)
+PORT80	:= $(shell expr $(GDBPORT) + 2)
+
 QEMUOPTS = -drive file=$(OBJDIR)/kern/kernel.img,index=0,media=disk,format=raw -serial mon:stdio -gdb tcp::$(GDBPORT)
 QEMUOPTS += $(shell if $(QEMU) -nographic -help | grep -q '^-D '; then echo '-D qemu.log'; fi)
 IMAGES = $(OBJDIR)/kern/kernel.img
 QEMUOPTS += -smp $(CPUS)
 QEMUOPTS += -drive file=$(OBJDIR)/fs/fs.img,index=1,media=disk,format=raw
 IMAGES += $(OBJDIR)/fs/fs.img
+QEMUOPTS += -net user -net nic,model=e1000 -redir tcp:$(PORT7)::7 \
+	   -redir tcp:$(PORT80)::80 -redir udp:$(PORT7)::7 -net dump,file=qemu.pcap
 QEMUOPTS += $(QEMUEXTRA)
 
 .gdbinit: .gdbinit.tmpl
@@ -161,6 +171,8 @@ gdb:
 	$(GDB) -n -x .gdbinit
 
 pre-qemu: .gdbinit
+#	QEMU doesn't truncate the pcap file.  Work around this.
+	@rm -f qemu.pcap
 
 qemu: $(IMAGES) pre-qemu
 	$(QEMU) $(QEMUOPTS)
@@ -308,6 +320,7 @@ myapi.key:
 #	@./handin-prep
 
 # For test runs
+prep-net_%: override INIT_CFLAGS+=-DTEST_NO_NS
 
 prep-%:
 	$(V)$(MAKE) "INIT_CFLAGS=${INIT_CFLAGS} -DTEST=`case $* in *_*) echo $*;; *) echo user_$*;; esac`" $(IMAGES)
@@ -324,6 +337,23 @@ run-%-nox: prep-% pre-qemu
 run-%: prep-% pre-qemu
 	$(QEMU) $(QEMUOPTS)
 
+# For network connections
+which-ports:
+	@echo "Local port $(PORT7) forwards to JOS port 7 (echo server)"
+	@echo "Local port $(PORT80) forwards to JOS port 80 (web server)"
+
+nc-80:
+	nc localhost $(PORT80)
+
+nc-7:
+	nc localhost $(PORT7)
+
+telnet-80:
+	telnet localhost $(PORT80)
+
+telnet-7:
+	telnet localhost $(PORT7)
+
 # This magic automatically generates makefile dependencies
 # for header files included from C source files we compile,
 # and keeps those dependencies up-to-date every time we recompile.