net: forward-port FreeBSD IPv6 stack with SLAAC + DHCPv6 autoconfig

Merge the upstream ipv6 branch (FreeBSD 9 netinet6 import + OSv glue) and add
boot-time IPv6 autoconfiguration:

- netinet6 stack (ip6, icmp6, nd6, in6_*, udp6, raw_ip6, mld6) behind conf-INET6
- OSv net-channel fast path, LRO, RCU classifier extended for IPv6/TCP
- Linux socket-option compat for 43 IPV6_* options; getifaddrs/netlink v6
- SLAAC: kernel Router Solicitation (nd6_rs_output) + accept-RA per-interface
  flag fix so a unikernel (no rtsold) autoconfigures from Router Advertisements
- DHCPv6 client (RFC 8415 stateful: SOLICIT/ADVERTISE/REQUEST/REPLY, DUID-LLT,
  IA_NA) triggered when the RA sets the Managed (M) flag, e.g. AWS VPC
- loader picks SLAAC vs DHCPv6 from RA flags; --ipv6 for IPv6-only boot
- all IPv6 code compile-gated (conf-INET6, conf_networking_dhcp6)
- tests: tst-tcp-v6-smoke, tst-ipv6-internet, tst-ifaddr-dump

Author: gburd

.travis.yml

@@ -23,7 +23,7 @@ before_install:
   - sudo adduser $USER libvirt
   - sudo adduser $USER kvm
   - echo "$DOCKER_ACCESS_TOKEN" | docker login --username osvunikernel --password-stdin
-  - pushd docker && docker build -t osv/builder -f ./Dockerfile.builder --build-arg DIST="ubuntu-20.10" . && popd
+  - pushd docker && docker build -t osv/builder -f ./Dockerfile.builder --build-arg DIST="ubuntu-20.10" --build-arg GIT_BRANCH="ipv6" . && popd
   - docker run -it --privileged -d --name build osv/builder
 stages:
   - build_and_publish

Makefile

@@ -361,7 +361,7 @@ COMMON = $(autodepend) -g -Wall -Wno-pointer-arith $(CFLAGS_WERROR) -Wformat=0 -
 	-fno-omit-frame-pointer $(compiler-specific) \
 	-include compiler/include/intrinsics.hh \
 	$(conf_compiler_cflags) $(conf_compiler_opt) $(acpi-defines) $(tracing-flags) $(gcc-sysroot) \
-	-D__OSV__ -D__XEN_INTERFACE_VERSION__="0x00030207" -DARCH_STRING=$(ARCH_STR) $(EXTRA_FLAGS)
+	$(configuration) -D__OSV__ -D__XEN_INTERFACE_VERSION__="0x00030207" -DARCH_STRING=$(ARCH_STR) $(EXTRA_FLAGS)
 COMMON += $(standard-includes-flag)
 
 tracing-flags-0 =
@@ -398,6 +398,11 @@ $(out)/bsd/%.o: INCLUDES += -isystem bsd/
 # for machine/
 $(out)/bsd/%.o: INCLUDES += -isystem bsd/$(arch)
 
+configuration-defines = conf-INET6
+
+configuration = $(foreach cf,$(configuration-defines), \
+                      -D$(cf:conf-%=CONF_%)=$($(cf)))
+
 makedir = $(call very-quiet, mkdir -p $(dir $@))
 build-so = $(CC) $(CFLAGS) -o $@ $^ $(EXTRA_LIBS)
 q-build-so = $(call quiet, $(build-so), LINK $@)
@@ -688,6 +693,41 @@ bsd += bsd/sys/netinet/cc/cc_cubic.o
 bsd += bsd/sys/netinet/cc/cc_htcp.o
 bsd += bsd/sys/netinet/cc/cc_newreno.o
 bsd += bsd/sys/netinet/arpcache.o
+ifeq ($(conf-INET6), 1)
+ifeq ($(conf_networking_dhcp6),1)
+bsd += bsd/porting/dhcp6.o
+endif
+bsd += bsd/sys/netinet6/dest6.o
+bsd += bsd/sys/netinet6/frag6.o
+bsd += bsd/sys/netinet6/icmp6.o
+$(out)/bsd/sys/netinet6/icmp6.o: COMMON+=-Wno-address-of-packed-member
+bsd += bsd/sys/netinet6/in6.o
+$(out)/bsd/sys/netinet6/in6.o: COMMON+=-fno-strict-aliasing
+bsd += bsd/sys/netinet6/in6_cksum.o
+bsd += bsd/sys/netinet6/in6_ifattach.o
+bsd += bsd/sys/netinet6/in6_mcast.o
+bsd += bsd/sys/netinet6/in6_pcb.o
+bsd += bsd/sys/netinet6/in6_proto.o
+bsd += bsd/sys/netinet6/in6_rmx.o
+$(out)/bsd/sys/netinet6/in6_rmx.o: COMMON+=-fno-strict-aliasing
+bsd += bsd/sys/netinet6/in6_src.o
+bsd += bsd/sys/netinet6/ip6_forward.o
+bsd += bsd/sys/netinet6/ip6_id.o
+bsd += bsd/sys/netinet6/ip6_input.o
+bsd += bsd/sys/netinet6/ip6_output.o
+bsd += bsd/sys/netinet6/mld6.o
+$(out)/bsd/sys/netinet6/mld6.o: COMMON+=-Wno-address-of-packed-member
+bsd += bsd/sys/netinet6/nd6.o
+$(out)/bsd/sys/netinet6/nd6.o: COMMON+=-fno-strict-aliasing
+bsd += bsd/sys/netinet6/nd6_nbr.o
+bsd += bsd/sys/netinet6/nd6_rtr.o
+$(out)/bsd/sys/netinet6/nd6_rtr.o: COMMON+=-fno-strict-aliasing
+bsd += bsd/sys/netinet6/raw_ip6.o
+$(out)/bsd/sys/netinet6/raw_ip6.o: COMMON+=-Wno-address-of-packed-member
+bsd += bsd/sys/netinet6/route6.o
+bsd += bsd/sys/netinet6/scope6.o
+bsd += bsd/sys/netinet6/udp6_usrreq.o
+endif
 endif
 ifeq ($(conf_drivers_xen),1)
 bsd += bsd/sys/xen/evtchn.o
@@ -1156,6 +1196,11 @@ objects += core/percpu-worker.o
 ifeq ($(conf_networking_dhcp),1)
 objects += core/dhcp.o
 endif
+ifeq ($(conf-INET6),1)
+ifeq ($(conf_networking_dhcp6),1)
+# bsd/porting/dhcp6.o is added to the bsd list (needs BSD-internal headers)
+endif
+endif
 objects += core/run.o
 objects += core/shutdown.o
 objects += core/version.o

bsd/net.cc

@@ -24,13 +24,22 @@
 #include <bsd/sys/net/ethernet.h>
 #include <bsd/sys/net/route.h>
 #include <bsd/sys/compat/linux/linux_netlink.h>
+#ifdef INET6
+#include <bsd/sys/netinet/icmp6.h>
+#include <bsd/sys/netinet6/in6.h>
+#include <bsd/sys/netinet6/mld6.h>
+#endif
 
 /* Generation of ip ids */
 void ip_initid(void);
 
 extern "C" {
     /* AF_INET */
     extern  struct domain inetdomain;
+#ifdef INET6
+    /* AF_INET6 */
+    extern  struct domain inet6domain;
+#endif
     /* AF_ROUTE */
     extern  struct domain routedomain;
     /* AF_NETLINK */
@@ -55,22 +64,34 @@ void net_init(void)
     vnet_pfil_init();
     domaininit(NULL);
     OSV_DOMAIN_SET(inet);
+#ifdef INET6
+    OSV_DOMAIN_SET(inet6);
+#endif
     OSV_DOMAIN_SET(route);
     OSV_DOMAIN_SET(netlink);
     rts_init();
     route_init();
     vnet_route_init();
     netlink_init();
+#ifdef INET6
+    ip6_init2(NULL);
+    mld_init(NULL);
+    vnet_mld_init(NULL);
+#endif
     ipport_tick_init(NULL);
     arp_init();
     domainfinalize(NULL);
     cc_init();
     if_attachdomain(NULL);
     vnet_loif_init();
 
+    /* Adding IPv4 address before starting the loopback interface
+     * cause the interface to be brought up without IPv6 support.
+     */
+
     /* Start the loopback device */
-    osv::start_if("lo0", "127.0.0.1", "255.0.0.0");
     osv::ifup("lo0");
+    osv::start_if("lo0", "127.0.0.1", "255.0.0.0");
 
     debug(" - done\n");
 }