kernel/linux.git/drivers/net/vrf.c, branch v5.15.7

vrf: Reset IPCB/IP6CB when processing outbound pkts in vrf dev xmit

2021-12-08T08:04:41+00:00

commit ee201011c1e1563c114a55c86eb164b236f18e84 upstream. IPCB/IP6CB need to be initialized when processing outbound v4 or v6 pkts in the codepath of vrf device xmit function so that leftover garbage doesn't cause futher code that uses the CB to incorrectly process the pkt. One occasion of the issue might occur when MPLS route uses the vrf device as the outgoing device such as when the route is added using "ip -f mpls route add dev " command. The problems seems to exist since day one. Hence I put the day one commits on the Fixes tags. Fixes: 193125dbd8eb ("net: Introduce VRF device driver") Fixes: 35402e313663 ("net: Add IPv6 support to VRF device") Cc: stable@vger.kernel.org Signed-off-by: Stephen Suryaputra Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20211130162637.3249-1-ssuryaextr@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

vrf: run conntrack only in context of lower/physdev for locally generated packets

2021-11-18T18:16:19+00:00

[ Upstream commit 8c9c296adfae9ea05f655d69e9f6e13daa86fb4a ] The VRF driver invokes netfilter for output+postrouting hooks so that users can create rules that check for 'oif $vrf' rather than lower device name. This is a problem when NAT rules are configured. To avoid any conntrack involvement in round 1, tag skbs as 'untracked' to prevent conntrack from picking them up. This gets cleared before the packet gets handed to the ip stack so conntrack will be active on the second iteration. One remaining issue is that a rule like output ... oif $vrfname notrack won't propagate to the second round because we can't tell 'notrack set via ruleset' and 'notrack set by vrf driver' apart. However, this isn't a regression: the 'notrack' removal happens instead of unconditional nf_reset_ct(). I'd also like to avoid leaking more vrf specific conditionals into the netfilter infra. For ingress, conntrack has already been done before the packet makes it to the vrf driver, with this patch egress does connection tracking with lower/physical device as well. Signed-off-by: Florian Westphal Acked-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

vrf: Revert "Reset skb conntrack connection..."

2021-10-20T10:27:19+00:00

This reverts commit 09e856d54bda5f288ef8437a90ab2b9b3eab83d1. When an interface is enslaved in a VRF, prerouting conntrack hook is called twice: once in the context of the original input interface, and once in the context of the VRF interface. If no special precausions are taken, this leads to creation of two conntrack entries instead of one, and breaks SNAT. Commit above was intended to avoid creation of extra conntrack entries when input interface is enslaved in a VRF. It did so by resetting conntrack related data associated with the skb when it enters VRF context. However it breaks netfilter operation. Imagine a use case when conntrack zone must be assigned based on the original input interface, rather than VRF interface (that would make original interfaces indistinguishable). One could create netfilter rules similar to these: chain rawprerouting { type filter hook prerouting priority raw; iif realiface1 ct zone set 1 return iif realiface2 ct zone set 2 return } This works before the mentioned commit, but not after: zone assignment is "forgotten", and any subsequent NAT or filtering that is dependent on the conntrack zone does not work. Here is a reproducer script that demonstrates the difference in behaviour. ========== #!/bin/sh # This script demonstrates unexpected change of nftables behaviour # caused by commit 09e856d54bda5f28 ""vrf: Reset skb conntrack # connection on VRF rcv" # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=09e856d54bda5f288ef8437a90ab2b9b3eab83d1 # # Before the commit, it was possible to assign conntrack zone to a # packet (or mark it for `notracking`) in the prerouting chanin, raw # priority, based on the `iif` (interface from which the packet # arrived). # After the change, # if the interface is enslaved in a VRF, such # assignment is lost. Instead, assignment based on the `iif` matching # the VRF master interface is honored. Thus it is impossible to # distinguish packets based on the original interface. # # This script demonstrates this change of behaviour: conntrack zone 1 # or 2 is assigned depending on the match with the original interface # or the vrf master interface. It can be observed that conntrack entry # appears in different zone in the kernel versions before and after # the commit. IPIN=172.30.30.1 IPOUT=172.30.30.2 PFXL=30 ip li sh vein >/dev/null 2>&1 && ip li del vein ip li sh tvrf >/dev/null 2>&1 && ip li del tvrf nft list table testct >/dev/null 2>&1 && nft delete table testct ip li add vein type veth peer veout ip li add tvrf type vrf table 9876 ip li set veout master tvrf ip li set vein up ip li set veout up ip li set tvrf up /sbin/sysctl -w net.ipv4.conf.veout.accept_local=1 /sbin/sysctl -w net.ipv4.conf.veout.rp_filter=0 ip addr add $IPIN/$PFXL dev vein ip addr add $IPOUT/$PFXL dev veout nft -f - <<__END__ table testct { chain rawpre { type filter hook prerouting priority raw; iif { veout, tvrf } meta nftrace set 1 iif veout ct zone set 1 return iif tvrf ct zone set 2 return notrack } chain rawout { type filter hook output priority raw; notrack } } __END__ uname -rv conntrack -F ping -W 1 -c 1 -I vein $IPOUT conntrack -L Signed-off-by: Eugene Crosser Acked-by: David Ahern Signed-off-by: David S. Miller

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

2021-08-20T01:09:18+00:00

drivers/ptp/Kconfig: 55c8fca1dae1 ("ptp_pch: Restore dependency on PCI") e5f31552674e ("ethernet: fix PTP_1588_CLOCK dependencies") Signed-off-by: Jakub Kicinski

vrf: Reset skb conntrack connection on VRF rcv

2021-08-16T23:37:01+00:00

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

vrf: fix NULL dereference in vrf_finish_output()

2021-08-06T22:40:37+00:00

The "skb" pointer is NULL on this error path so we can't dereference it. Use "dev" instead. Fixes: 14ee70ca89e6 ("vrf: use skb_expand_head in vrf_finish_output") Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/20210806150435.GB15586@kili Signed-off-by: Jakub Kicinski

vrf: use skb_expand_head in vrf_finish_output

2021-08-03T10:21:39+00:00

Unlike skb_realloc_headroom, new helper skb_expand_head does not allocate a new skb if possible. Signed-off-by: Vasily Averin Signed-off-by: David S. Miller

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

2021-06-29T22:45:27+00:00

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

2021-06-21T18:50:04+00:00

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

2021-06-19T02:47:02+00:00

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