Date: Wed, 31 Mar 2021 11:17:06 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 254675] ICMP Unreach needfrag is broken in 13.0-RC4 Message-ID: <bug-254675-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D254675 Bug ID: 254675 Summary: ICMP Unreach needfrag is broken in 13.0-RC4 Product: Base System Version: 13.0-STABLE Hardware: Any OS: Any Status: New Severity: Affects Many People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: afedorov@FreeBSD.org Hello. I have the following setup with two VM's: <public net> --- [ FreeBSD 13.0 RC4 GW_VM + NAT ] --- <private net> --- [Li= nux VM] GW_VM: Interfaces: vtnet1 <public ip> vtnet2 192.168.1.1/24 net.inet.ip.forwarding=3D1 NAT pf.conf: nat on vtnet1 from 192.168.1.0/24 to any -> vtnet1 Linux VM: enp0s2 192.168.1 When I'm trying iperf3 from Linux VM to public host: [ 4] local 192.168.1.4 port 49412 connected to <PUBLIC_HOST> port 5201 [ ID] Interval Transfer Bandwidth Retr Cwnd [ 4] 0.00-1.01 sec 263 KBytes 2.14 Mbits/sec 45 5.66 KBytes=20= =20=20=20=20=20=20 [ 4] 1.01-2.00 sec 156 KBytes 1.28 Mbits/sec 32 5.66 KBytes=20= =20=20=20=20=20=20 [ 4] 2.00-3.00 sec 156 KBytes 1.27 Mbits/sec 26 5.66 KBytes=20= =20=20=20=20=20=20 The low upload speed is predictable due to virtio-net offload are enabled. But what I did not expect was the absence of the needfrag ICMP packet. I setup 12.2 RELEASE with same configuration, and root@edge-12:~ # tcpdump -i vtnet2 proto ICMP tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on vtnet2, link-type EN10MB (Ethernet), capture size 262144 bytes 14:07:09.803538 IP 192.168.1.1 > 192.168.1.4: ICMP 10.78.28.17 unreachable - need to frag (mtu 1500), length 176 14:07:09.803581 IP 192.168.1.1 > 192.168.1.4: ICMP 10.78.28.17 unreachable - need to frag (mtu 1500), length 176 14:07:09.803605 IP 192.168.1.1 > 192.168.1.4: ICMP 10.78.28.17 unreachable - need to frag (mtu 1500), length 176 14:07:09.806829 IP 192.168.1.1 > 192.168.1.4: ICMP 10.78.28.17 unreachable - need to frag (mtu 1500), length 176 14:07:09.806856 IP 192.168.1.1 > 192.168.1.4: ICMP 10.78.28.17 unreachable - need to frag (mtu 1500), length 176 14:07:09.810143 IP 192.168.1.1 > 192.168.1.4: ICMP 10.78.28.17 unreachable - need to frag (mtu 1500), length 176 14:07:09.810172 IP 192.168.1.1 > 192.168.1.4: ICMP 10.78.28.17 unreachable - need to frag (mtu 1500), length 176 Using the following DTrace script: dtrace -n 'fbt:kernel:icmp_error:entry { stack(); printf("type: %d code: %d", arg1, arg2);}' 12.2-RELEASE work as expected: ip_forward() call ip_output() which return EMSGSIZE -> generate ICMP unreach needsfrag. 0 53981 icmp_error:entry=20 kernel`ip_forward+0x5c4 kernel`ip_input+0x7a7 kernel`netisr_dispatch_src+0xca kernel`ether_demux+0x138 kernel`ether_nh_input+0x33b kernel`netisr_dispatch_src+0xca kernel`ether_input+0x4b kernel`vtnet_rxq_eof+0x7a5 kernel`vtnet_rx_vq_process+0xb7 kernel`ithread_loop+0x23c kernel`fork_exit+0x7e kernel`0xffffffff81067f6e type: 3 code: 4 0 53981 icmp_error:entry=20 kernel`ip_forward+0x5c4 kernel`ip_input+0x7a7 kernel`netisr_dispatch_src+0xca kernel`ether_demux+0x138 kernel`ether_nh_input+0x33b kernel`netisr_dispatch_src+0xca kernel`ether_input+0x4b kernel`vtnet_rxq_eof+0x7a5 kernel`vtnet_rx_vq_process+0xb7 kernel`ithread_loop+0x23c kernel`fork_exit+0x7e kernel`0xffffffff81067f6e type: 3 code: 4 13-RC4: 0 54326 icmp_error:entry=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20 kernel`ip_tryforward+0x730=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20 kernel`ip_input+0x356=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20 kernel`netisr_dispatch_src+0xca=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20 kernel`ether_demux+0x148=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20 kernel`ether_nh_input+0x34c=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20 kernel`netisr_dispatch_src+0xca=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20 kernel`ether_input+0x69=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20 kernel`vtnet_rxq_eof+0x7d4=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20 kernel`vtnet_rx_vq_process+0xb7=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20 kernel`ithread_loop+0x24d=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20 kernel`fork_exit+0x7e=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20 kernel`0xffffffff810625ae=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20 type: 3 code: 4=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20 1 54326 icmp_error:entry=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20 kernel`ip_forward+0x9c=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20 kernel`ip_input+0x6cc=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20 kernel`swi_net+0x12b=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20 kernel`ithread_loop+0x24d=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20 kernel`fork_exit+0x7e=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20 kernel`0xffffffff810625ae=20 type: 3 code: 1 So, As I understand ip_tryforward() trying to generate ICMP needsfrag, but after that generated ICMP ICMP_UNREACH_HOST. --=20 You are receiving this mail because: You are the assignee for the bug.=
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