pm24.git/drivers/net/vrf.c, branch v5.14

vrf: Reset skb conntrack connection on VRF rcv

2021-08-16T23:37:01Z

To fix the "reverse-NAT" for replies. When a packet is sent over a VRF, the POST_ROUTING hooks are called twice: Once from the VRF interface, and once from the "actual" interface the packet will be sent from: 1) First SNAT: l3mdev_l3_out() -> vrf_l3_out() -> .. -> vrf_output_direct() This causes the POST_ROUTING hooks to run. 2) Second SNAT: 'ip_output()' calls POST_ROUTING hooks again. Similarly for replies, first ip_rcv() calls PRE_ROUTING hooks, and second vrf_l3_rcv() calls them again. As an example, consider the following SNAT rule: > iptables -t nat -A POSTROUTING -p udp -m udp --dport 53 -j SNAT --to-source 2.2.2.2 -o vrf_1 In this case sending over a VRF will create 2 conntrack entries. The first is from the VRF interface, which performs the IP SNAT. The second will run the SNAT, but since the "expected reply" will remain the same, conntrack randomizes the source port of the packet: e..g With a socket bound to 1.1.1.1:10000, sending to 3.3.3.3:53, the conntrack rules are: udp 17 29 src=2.2.2.2 dst=3.3.3.3 sport=10000 dport=53 packets=1 bytes=68 [UNREPLIED] src=3.3.3.3 dst=2.2.2.2 sport=53 dport=61033 packets=0 bytes=0 mark=0 use=1 udp 17 29 src=1.1.1.1 dst=3.3.3.3 sport=10000 dport=53 packets=1 bytes=68 [UNREPLIED] src=3.3.3.3 dst=2.2.2.2 sport=53 dport=10000 packets=0 bytes=0 mark=0 use=1 i.e. First SNAT IP from 1.1.1.1 --> 2.2.2.2, and second the src port is SNAT-ed from 10000 --> 61033. But when a reply is sent (3.3.3.3:53 -> 2.2.2.2:61033) only the later conntrack entry is matched: udp 17 29 src=2.2.2.2 dst=3.3.3.3 sport=10000 dport=53 packets=1 bytes=68 src=3.3.3.3 dst=2.2.2.2 sport=53 dport=61033 packets=1 bytes=49 mark=0 use=1 udp 17 28 src=1.1.1.1 dst=3.3.3.3 sport=10000 dport=53 packets=1 bytes=68 [UNREPLIED] src=3.3.3.3 dst=2.2.2.2 sport=53 dport=10000 packets=0 bytes=0 mark=0 use=1 And a "port 61033 unreachable" ICMP packet is sent back. The issue is that when PRE_ROUTING hooks are called from vrf_l3_rcv(), the skb already has a conntrack flow attached to it, which means nf_conntrack_in() will not resolve the flow again. This means only the dest port is "reverse-NATed" (61033 -> 10000) but the dest IP remains 2.2.2.2, and since the socket is bound to 1.1.1.1 it's not received. This can be verified by logging the 4-tuple of the packet in '__udp4_lib_rcv()'. The fix is then to reset the flow when skb is received on a VRF, to let conntrack resolve the flow again (which now will hit the earlier flow). To reproduce: (Without the fix "Got pkt_to_nat_port" will not be printed by running 'bash ./repro'): $ cat run_in_A1.py import logging logging.getLogger("scapy.runtime").setLevel(logging.ERROR) from scapy.all import * import argparse def get_packet_to_send(udp_dst_port, msg_name): return Ether(src='11:22:33:44:55:66', dst=iface_mac)/ \ IP(src='3.3.3.3', dst='2.2.2.2')/ \ UDP(sport=53, dport=udp_dst_port)/ \ Raw(f'{msg_name}\x0012345678901234567890') parser = argparse.ArgumentParser() parser.add_argument('-iface_mac', dest="iface_mac", type=str, required=True, help="From run_in_A3.py") parser.add_argument('-socket_port', dest="socket_port", type=str, required=True, help="From run_in_A3.py") parser.add_argument('-v1_mac', dest="v1_mac", type=str, required=True, help="From script") args, _ = parser.parse_known_args() iface_mac = args.iface_mac socket_port = int(args.socket_port) v1_mac = args.v1_mac print(f'Source port before NAT: {socket_port}') while True: pkts = sniff(iface='_v0', store=True, count=1, timeout=10) if 0 == len(pkts): print('Something failed, rerun the script :(', flush=True) break pkt = pkts[0] if not pkt.haslayer('UDP'): continue pkt_sport = pkt.getlayer('UDP').sport print(f'Source port after NAT: {pkt_sport}', flush=True) pkt_to_send = get_packet_to_send(pkt_sport, 'pkt_to_nat_port') sendp(pkt_to_send, '_v0', verbose=False) # Will not be received pkt_to_send = get_packet_to_send(socket_port, 'pkt_to_socket_port') sendp(pkt_to_send, '_v0', verbose=False) break $ cat run_in_A2.py import socket import netifaces print(f"{netifaces.ifaddresses('e00000')[netifaces.AF_LINK][0]['addr']}", flush=True) s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) s.setsockopt(socket.SOL_SOCKET, socket.SO_BINDTODEVICE, str('vrf_1' + '\0').encode('utf-8')) s.connect(('3.3.3.3', 53)) print(f'{s. getsockname()[1]}', flush=True) s.settimeout(5) while True: try: # Periodically send in order to keep the conntrack entry alive. s.send(b'a'*40) resp = s.recvfrom(1024) msg_name = resp[0].decode('utf-8').split('\0')[0] print(f"Got {msg_name}", flush=True) except Exception as e: pass $ cat repro.sh ip netns del A1 2> /dev/null ip netns del A2 2> /dev/null ip netns add A1 ip netns add A2 ip -n A1 link add _v0 type veth peer name _v1 netns A2 ip -n A1 link set _v0 up ip -n A2 link add e00000 type bond ip -n A2 link add lo0 type dummy ip -n A2 link add vrf_1 type vrf table 10001 ip -n A2 link set vrf_1 up ip -n A2 link set e00000 master vrf_1 ip -n A2 addr add 1.1.1.1/24 dev e00000 ip -n A2 link set e00000 up ip -n A2 link set _v1 master e00000 ip -n A2 link set _v1 up ip -n A2 link set lo0 up ip -n A2 addr add 2.2.2.2/32 dev lo0 ip -n A2 neigh add 1.1.1.10 lladdr 77:77:77:77:77:77 dev e00000 ip -n A2 route add 3.3.3.3/32 via 1.1.1.10 dev e00000 table 10001 ip netns exec A2 iptables -t nat -A POSTROUTING -p udp -m udp --dport 53 -j \ SNAT --to-source 2.2.2.2 -o vrf_1 sleep 5 ip netns exec A2 python3 run_in_A2.py > x & XPID=$! sleep 5 IFACE_MAC=`sed -n 1p x` SOCKET_PORT=`sed -n 2p x` V1_MAC=`ip -n A2 link show _v1 | sed -n 2p | awk '{print $2'}` ip netns exec A1 python3 run_in_A1.py -iface_mac ${IFACE_MAC} -socket_port \ ${SOCKET_PORT} -v1_mac ${SOCKET_PORT} sleep 5 kill -9 $XPID wait $XPID 2> /dev/null ip netns del A1 ip netns del A2 tail x -n 2 rm x set +x Fixes: 73e20b761acf ("net: vrf: Add support for PREROUTING rules on vrf device") Signed-off-by: Lahav Schlesinger Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20210815120002.2787653-1-lschlesinger@drivenets.com Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-06-29T22:45:27Z

Trivial conflict in net/netfilter/nf_tables_api.c. Duplicate fix in tools/testing/selftests/net/devlink_port_split.py - take the net-next version. skmsg, and L4 bpf - keep the bpf code but remove the flags and err params. Signed-off-by: Jakub Kicinski

vrf: do not push non-ND strict packets with a source LLA through packet taps again

2021-06-21T18:50:04Z

Non-ND strict packets with a source LLA go through the packet taps again, while non-ND strict packets with other source addresses do not, and we can see a clone of those packets on the vrf interface (we should not). This is due to a series of changes: Commit 6f12fa775530[1] made non-ND strict packets not being pushed again in the packet taps. This changed with commit 205704c618af[2] for those packets having a source LLA, as they need a lookup with the orig_iif. The issue now is those packets do not skip the 'vrf_ip6_rcv' function to the end (as the ones without a source LLA) and go through the check to call packet taps again. This check was changed by commit 6f12fa775530[1] and do not exclude non-strict packets anymore. Packets matching 'need_strict && !is_ndisc && is_ll_src' are now being sent through the packet taps again. This can be seen by dumping packets on the vrf interface. Fix this by having the same code path for all non-ND strict packets and selectively lookup with the orig_iif for those with a source LLA. This has the effect to revert to the pre-205704c618af[2] condition, which should also be easier to maintain. [1] 6f12fa775530 ("vrf: mark skb for multicast or link-local as enslaved to VRF") [2] 205704c618af ("vrf: packets with lladdr src needs dst at input with orig_iif when needs strict") Fixes: 205704c618af ("vrf: packets with lladdr src needs dst at input with orig_iif when needs strict") Cc: Stephen Suryaputra Reported-by: Paolo Abeni Signed-off-by: Antoine Tenart Reviewed-by: David Ahern Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-06-19T02:47:02Z

Trivial conflicts in net/can/isotp.c and tools/testing/selftests/net/mptcp/mptcp_connect.sh scaled_ppm_to_ppb() was moved from drivers/ptp/ptp_clock.c to include/linux/ptp_clock_kernel.h in -next so re-apply the fix there. Signed-off-by: Jakub Kicinski

vrf: fix maximum MTU

2021-06-08T18:46:23Z

My initial goal was to fix the default MTU, which is set to 65536, ie above the maximum defined in the driver: 65535 (ETH_MAX_MTU). In fact, it's seems more consistent, wrt min_mtu, to set the max_mtu to IP6_MAX_MTU (65535 + sizeof(struct ipv6hdr)) and use it by default. Let's also, for consistency, set the mtu in vrf_setup(). This function calls ether_setup(), which set the mtu to 1500. Thus, the whole mtu config is done in the same function. Before the patch: $ ip link add blue type vrf table 1234 $ ip link list blue 9: blue: mtu 65536 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether fa:f5:27:70:24:2a brd ff:ff:ff:ff:ff:ff $ ip link set dev blue mtu 65535 $ ip link set dev blue mtu 65536 Error: mtu greater than device maximum. Fixes: 5055376a3b44 ("net: vrf: Fix ping failed when vrf mtu is set to 0") CC: Miaohe Lin Signed-off-by: Nicolas Dichtel Reviewed-by: David Ahern Signed-off-by: David S. Miller

vrf: Fix a typo

2021-06-02T00:05:04Z

possibile ==> possible Signed-off-by: Zheng Yongjun Reviewed-by: David Ahern Signed-off-by: David S. Miller

vrf: fix a comment about loopback device

2021-04-14T20:13:53Z

This is a leftover of the below commit. Fixes: 4f04256c983a ("net: vrf: Drop local rtable and rt6_info") Signed-off-by: Nicolas Dichtel Acked-by: David Ahern Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-12-12T06:29:38Z

xdp_return_frame_bulk() needs to pass a xdp_buff to __xdp_return(). strlcpy got converted to strscpy but here it makes no functional difference, so just keep the right code. Conflicts: net/netfilter/nf_tables_api.c Signed-off-by: Jakub Kicinski

vrf: handle CONFIG_IPV6 not set for vrf_add_mac_header_if_unset()

2020-12-09T20:00:40Z

The vrf_add_mac_header_if_unset() is defined within a conditional compilation block which depends on the CONFIG_IPV6 macro. However, the vrf_add_mac_header_if_unset() needs to be called also by IPv4 related code and when the CONFIG_IPV6 is not set, this function is missing. As a consequence, the build process stops reporting the error: ERROR: implicit declaration of function 'vrf_add_mac_header_if_unset' The problem is solved by *only* moving functions vrf_add_mac_header_if_unset() and vrf_prepare_mac_header() out of the conditional block. Reported-by: kernel test robot Fixes: 0489390882202 ("vrf: add mac header for tunneled packets when sniffer is attached") Signed-off-by: Andrea Mayer Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20201208175210.8906-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski

vrf: packets with lladdr src needs dst at input with orig_iif when needs strict

2020-12-05T21:46:07Z

Depending on the order of the routes to fe80::/64 are installed on the VRF table, the NS for the source link-local address of the originator might be sent to the wrong interface. This patch ensures that packets with link-local addr source is doing a lookup with the orig_iif when the destination addr indicates that it is strict. Add the reproducer as a use case in self test script fcnal-test.sh. Fixes: b4869aa2f881 ("net: vrf: ipv6 support for local traffic to local addresses") Signed-off-by: Stephen Suryaputra Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20201204030604.18828-1-ssuryaextr@gmail.com Signed-off-by: Jakub Kicinski