scripts: add --user-network to qemustart

qemustart is a handy script to quickly test OpenWrt firmware using
qemu.  Bringing up networking currently requires a bridge-helper
setup with privileged IP and bridge assignment.  To simplify
testing scenarios like the package manager, which need both shell
access and outbound internet, add a user-mode networking option
backed by SLIRP that requires no privileges.

To stay backward compatible, the defaults don't change.  The new
flag --user-network attaches two NICs (LAN + WAN) and forwards
three host ports to the guest LAN interface (192.168.1.1):
2222 -> 22 (ssh), 8080 -> 80 (http) and 8443 -> 443 (https).  The
host-side ports can be overridden with --ssh-port, --http-port
and --https-port.

Link: https://github.com/openwrt/openwrt/pull/23424
Signed-off-by: Paul Spooren <mail@aparcar.org>

diff --git a/scripts/qemustart b/scripts/qemustart
index 568b35876546d529b3d080662f0a51ffef95fe38..c7118095ef8530cc168832a53895ba9a39c4b2e7 100755 (executable)
--- a/scripts/qemustart
+++ b/scripts/qemustart
@@ -75,11 +75,36 @@ check_setup_() {
 
 check_setup() {
        [ -n "$o_network" ] || return 0
+       [ -z "$o_user" ] || return 0
        check_setup_ || {
                __errmsg "please check the script content to see the environment requirement"
                return 1
        }
 }
+
+# Append user-mode networking args to o_qemu_extra.  $1 is the qemu NIC device
+# (e.g. virtio-net-pci, e1000).  The LAN netdev shares OpenWrt's default LAN
+# subnet so the guest's static 192.168.1.1 is reachable through SLIRP; the WAN
+# netdev uses SLIRP defaults (10.0.2.0/24) to provide internet via the host.
+add_user_netdev() {
+       local nic="$1"
+       local ssh="${o_ssh_port:-2222}"
+       local http="${o_http_port:-8080}"
+       local https="${o_https_port:-8443}"
+       __errmsg "user-mode networking: ssh on 127.0.0.1:$ssh, http on 127.0.0.1:$http, https on 127.0.0.1:$https"
+
+       local lan="user,id=lan,net=192.168.1.0/24,host=192.168.1.2"
+       lan+=",hostfwd=tcp:127.0.0.1:$ssh-192.168.1.1:22"
+       lan+=",hostfwd=tcp:127.0.0.1:$http-192.168.1.1:80"
+       lan+=",hostfwd=tcp:127.0.0.1:$https-192.168.1.1:443"
+
+       o_qemu_extra+=(
+               -netdev "$lan"
+               -device "$nic,id=devlan,netdev=lan,mac=$MAC_LAN"
+               -netdev "user,id=wan"
+               -device "$nic,id=devwan,netdev=wan,mac=$MAC_WAN"
+       )
+}
 #do_setup; check_setup; exit $?
 
 usage() {
@@ -91,6 +116,7 @@ Usage: $SELF [-h|--help]
          [--rootfs <rootfs>]
          [--machine <machine>]
          [-n|--network]
+         [-u|--user-network [--ssh-port <port>] [--http-port <port>] [--https-port <port>]]
 
 <subtarget> will default to "generic" and must be specified if
 <extra-qemu-options> are present
@@ -100,15 +126,31 @@ e.g. <subtarget> for malta can be le, be, le64, be64, le-glibc, le64-glibc, etc
 <kernel>, <rootfs> can be required or optional arguments to qemu depending on
 the actual <target> in use.  They will default to files under bin/targets/
 
+Networking modes:
+  -n / --network        use bridges \$BR_LAN and \$BR_WAN (needs sudo + helper
+                        setup)
+  -u / --user-network   use rootless qemu user-mode networking; the guest LAN
+                        interface (static 192.168.1.1) is reachable from the
+                        host via 127.0.0.1:<ssh-port> (default 2222),
+                        127.0.0.1:<http-port> (default 8080) and
+                        127.0.0.1:<https-port> (default 8443); the guest WAN
+                        gets internet via SLIRP
+  --ssh-port <p>        override host-side ssh forward port (default 2222)
+  --http-port <p>       override host-side http forward port (default 8080)
+  --https-port <p>      override host-side https forward port (default 8443)
+
 Examples
 
   $SELF x86 64
+  $SELF x86 64 --user-network
+  $SELF x86 64 --user-network --ssh-port 2200 --http-port 8000 --https-port 8001
   $SELF x86 64 --machine q35,accel=kvm -device virtio-balloon-pci
   $SELF x86 64 -incoming tcp:0:4444
   $SELF x86 64-glibc
   $SELF malta be -m 64
   $SELF malta le64
   $SELF malta be-glibc
+  $SELF armsr armv8 --user-network
   $SELF armsr armv7 \\
                 --machine virt,highmem=off \\
                 --kernel bin/targets/armsr/armv7/openwrt-armsr-armv7-generic-kernel.bin \\
@@ -122,6 +164,7 @@ rand_mac() {
 
 parse_args() {
        o_network=
+       o_user=
        o_qemu_extra=()
        while [ "$#" -gt 0 ]; do
                # Cmdline options for the script itself SHOULD try to be
@@ -134,6 +177,10 @@ parse_args() {
                        --rootfs) o_rootfs="$2"; shift 2 ;;
                        --machine|-machine|-M) o_mach="$2"; shift 2 ;;
                        --network|-n) o_network=1; shift ;;
+                       --user-network|-u) o_user=1; o_network=1; shift ;;
+                       --ssh-port) o_ssh_port="$2"; shift 2 ;;
+                       --http-port) o_http_port="$2"; shift 2 ;;
+                       --https-port) o_https_port="$2"; shift 2 ;;
                        --help|-h)
                                usage
                                exit 0
@@ -196,12 +243,16 @@ start_qemu_armsr() {
        }
 
        [ -z "$o_network" ] || {
-               o_qemu_extra+=( \
-                       "-netdev" "bridge,id=lan,br=$BR_LAN,helper=$HELPER" \
-                           "-device" "virtio-net-pci,id=devlan,netdev=lan,mac=$MAC_LAN" \
-                       "-netdev" "bridge,id=wan,br=$BR_WAN,helper=$HELPER" "-device" \
-                           "virtio-net-pci,id=devwan,netdev=wan,mac=$MAC_WAN" \
-               )
+               if [ -n "$o_user" ]; then
+                       add_user_netdev virtio-net-pci
+               else
+                       o_qemu_extra+=( \
+                               "-netdev" "bridge,id=lan,br=$BR_LAN,helper=$HELPER" \
+                                   "-device" "virtio-net-pci,id=devlan,netdev=lan,mac=$MAC_LAN" \
+                               "-netdev" "bridge,id=wan,br=$BR_WAN,helper=$HELPER" "-device" \
+                                   "virtio-net-pci,id=devwan,netdev=wan,mac=$MAC_WAN" \
+                       )
+               fi
        }
 
        "$qemu_exe" -machine "$mach" -cpu "$cpu" -nographic \
@@ -236,14 +287,18 @@ start_qemu_malta() {
                )
        }
 
-       # NOTE: order of wan, lan -device arguments matters as it will affect which
-       # one will be actually used as the wan, lan network interface inside the
-       # guest machine
+       # NOTE: order of -device arguments matters: the first -device becomes eth0
+       # in the guest, which OpenWrt's 99-default_network assigns as LAN; the
+       # second becomes eth1 / WAN.  Keep LAN first to match that mapping.
        [ -z "$o_network" ] || {
-               o_qemu_extra+=(
-                       -netdev bridge,id=lan,br="$BR_LAN,helper=$HELPER" -device pcnet,netdev=lan,mac="$MAC_LAN"
-                       -netdev bridge,id=wan,br="$BR_WAN,helper=$HELPER" -device pcnet,netdev=wan,mac="$MAC_WAN"
-               )
+               if [ -n "$o_user" ]; then
+                       add_user_netdev pcnet
+               else
+                       o_qemu_extra+=(
+                               -netdev bridge,id=lan,br="$BR_LAN,helper=$HELPER" -device pcnet,netdev=lan,mac="$MAC_LAN"
+                               -netdev bridge,id=wan,br="$BR_WAN,helper=$HELPER" -device pcnet,netdev=wan,mac="$MAC_WAN"
+                       )
+               fi
        }
 
        "$qemu_exe" -machine "$mach" -cpu "$cpu" -nographic \
@@ -287,16 +342,24 @@ start_qemu_x86() {
        [ -z "$o_network" ] || {
                case "${o_subtarget%-*}" in
                        legacy)
-                               o_qemu_extra+=(
-                                       -netdev "bridge,id=lan,br=$BR_LAN,helper=$HELPER" -device "e1000,id=devlan,netdev=lan,mac=$MAC_LAN"
-                                       -netdev "bridge,id=wan,br=$BR_WAN,helper=$HELPER" -device "e1000,id=devwan,netdev=wan,mac=$MAC_WAN"
-                               )
+                               if [ -n "$o_user" ]; then
+                                       add_user_netdev e1000
+                               else
+                                       o_qemu_extra+=(
+                                               -netdev "bridge,id=lan,br=$BR_LAN,helper=$HELPER" -device "e1000,id=devlan,netdev=lan,mac=$MAC_LAN"
+                                               -netdev "bridge,id=wan,br=$BR_WAN,helper=$HELPER" -device "e1000,id=devwan,netdev=wan,mac=$MAC_WAN"
+                                       )
+                               fi
                                ;;
                        generic|64)
-                               o_qemu_extra+=(
-                                       -netdev "bridge,id=lan,br=$BR_LAN,helper=$HELPER" -device "virtio-net-pci,id=devlan,netdev=lan,mac=$MAC_LAN"
-                                       -netdev "bridge,id=wan,br=$BR_WAN,helper=$HELPER" -device "virtio-net-pci,id=devwan,netdev=wan,mac=$MAC_WAN"
-                               )
+                               if [ -n "$o_user" ]; then
+                                       add_user_netdev virtio-net-pci
+                               else
+                                       o_qemu_extra+=(
+                                               -netdev "bridge,id=lan,br=$BR_LAN,helper=$HELPER" -device "virtio-net-pci,id=devlan,netdev=lan,mac=$MAC_LAN"
+                                               -netdev "bridge,id=wan,br=$BR_WAN,helper=$HELPER" -device "virtio-net-pci,id=devwan,netdev=wan,mac=$MAC_WAN"
+                                       )
+                               fi
                                ;;
                esac
        }