增加对dhcpv4的支持（tcp、udp socket已写好，但由于缺少epoll机制，尚未完整测试） (#237)

* 为virtio网卡完成smoltcp的phy层配置

* raw socket

* 初步写完udp和tcp socket

* 能够正常通过dhcp获取ipv4地址（具有全局iface btree)

---------

Co-authored-by: guanjinquan <1666320330@qq.com>

tools/configure_network.sh

@@ -0,0 +1,27 @@
+# Replace with your wired Ethernet interface name
+ETH=eno1
+
+sudo modprobe bridge
+sudo modprobe br_netfilter
+
+sudo sysctl -w net.bridge.bridge-nf-call-arptables=0
+sudo sysctl -w net.bridge.bridge-nf-call-ip6tables=0
+sudo sysctl -w net.bridge.bridge-nf-call-iptables=0
+
+sudo ip tuntap add name tap0 mode tap user $USER
+sudo brctl addbr br0
+sudo brctl addif br0 tap0
+sudo brctl addif br0 $ETH
+sudo ip link set tap0 up
+sudo ip link set $ETH up
+sudo ip link set br0 up
+
+
+# This connects your host system to the internet, so you can use it
+# at the same time you run the examples.
+sudo dhcpcd br0
+
+sudo mkdir -p /usr/local/etc/qemu
+sudo mkdir -p /etc/qemu
+sudo sh -c 'echo "allow br0" > /usr/local/etc/qemu/bridge.conf'
+sudo sh -c 'echo "allow br0" > /etc/qemu/bridge.conf'

tools/run-qemu.sh

@@ -6,7 +6,7 @@ echo "$@"
 allflags=$(qemu-system-x86_64 -cpu help | awk '/flags/ {y=1; getline}; y {print}' | tr ' ' '\n' | grep -Ev "^$" | sed -r 's|^|+|' | tr '\n' ',' | sed -r "s|,$||")
 ARCH="x86_64"
 #ARCH="i386"
-# 请根据自己的需要，在-d 后方加入所需的trace事件
+# 请根据自己的需要，在-d 后方加入所需的 trace 事件
 
 # 标准的trace events
 qemu_trace_std=cpu_reset,guest_errors,exec,cpu,trace:virtio*
@@ -29,7 +29,7 @@ QEMU_RTC_CLOCK="clock=host,base=localtime"
 QEMU_SERIAL="file:../serial_opt.txt"
 QEMU_DRIVE="id=disk,file=${QEMU_DISK_IMAGE},if=none"
 
-QEMU_DEVICES="-device ahci,id=ahci -device ide-hd,drive=disk,bus=ahci.0 -nic user,model=virtio  -usb -device qemu-xhci,id=xhci,p2=8,p3=4 -machine accel=${qemu_accel}"
+QEMU_DEVICES="-device ahci,id=ahci -device ide-hd,drive=disk,bus=ahci.0 -nic user,model=virtio-net-pci -usb -device qemu-xhci,id=xhci,p2=8,p3=4 -machine accel=${qemu_accel}"
 
 QEMU_ARGUMENT="-d ${QEMU_DISK_IMAGE} -m ${QEMU_MEMORY} -smp ${QEMU_SMP} -boot order=d -monitor ${QEMU_MONITOR} -d ${qemu_trace_std} "