Hoi Stanislav, Thanks for the response. As I noted in my original email, I am aware that loopbacks work as BVI members, but since they are there (and have a whole device class dedicated to them!) I was hoping to (a) get some historical context on the need/differences between BVI and Loopback devices, and (b) get to the bottom of this bug and fix it :)
I can certainly work around the bug for now by dedicating a set of loopback interfaces and avoiding the use of BVIs, for now. groet, Pim On Sun, Mar 27, 2022 at 12:43 PM Stanislav Zaikin <zsta...@gmail.com> wrote: > Hi Pim, > > Well, I wasn't aware of "bvi ..." commands. Anyway, usually I go with > something like: > > create loopback interface instance 20 > set interface state loop20 up > create bridge-domain 20 learn 1 forward 1 flood 1 arp-term 1 arp-ufwd 0 > set interface l2 bridge loop20 20 bvi > > On Sun, 27 Mar 2022 at 00:41, Pim van Pelt <p...@ipng.nl> wrote: > >> Hoi, >> >> I've noticed that a pattern of 'create loopback; delete loopback; create >> bvi' as well as 'create bvi; delete bvi; create loopback' makes VPP at HEAD >> unhappy. >> I've actually long since wondered what the difference is between BVI and >> Loopback interface types, other than the BVI plumbing lives in l2/l2_bvi.c >> and the loopback lives in ethernet/interface.c their _use_ seems very >> similar if not identical. I understand that BVIs are used in bridges, but a >> loopback in practice serves that purpose equally well. >> >> I assume the issue is in the bvi/loop deletion not the creation, but I >> stared at this for an hour or so and could not understand it. Can somebody >> more knowledgeable help me out ? >> Take the following simple repro to crash VPP. The assertion in noce.c:194 >> fails in both cases: >> >> *1) create loop after bvi:* >> DBGvpp# show version >> vpp v22.06-rc0~268-g4859d8d8e built by pim on hippo at 2022-03-23T19:23:53 >> DBGvpp# bvi create instance 0 >> bvi0 >> DBGvpp# bvi delete bvi0 >> DBGvpp# create loopback interface instance 0 >> >> *0: /home/pim/src/vpp/src/vlib/node.c:194 (vlib_node_add_next_with_slot) >> assertion `slot == p[0]' fails* >> Thread 1 "vpp_main" received signal SIGABRT, Aborted. >> __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 >> 50 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory. >> (gdb) bt >> #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 >> #1 0x00007ffff69de859 in __GI_abort () at abort.c:79 >> #2 0x00000000004072f3 in os_panic () at >> /home/pim/src/vpp/src/vpp/vnet/main.c:413 >> #3 0x00007ffff6d2ebc9 in debugger () at >> /home/pim/src/vpp/src/vppinfra/error.c:84 >> #4 0x00007ffff6d2e92d in _clib_error (how_to_die=2, function_name=0x0, >> line_number=0, fmt=0x7ffff6f3b19c "%s:%d (%s) assertion `%s' fails") >> at /home/pim/src/vpp/src/vppinfra/error.c:143 >> #5 0x00007ffff6ea462b in vlib_node_add_next_with_slot >> (vm=0x7fff96800740, node_index=696, next_node_index=648, slot=2) >> at /home/pim/src/vpp/src/vlib/node.c:194 >> #6 0x00007ffff6ea61d8 in vlib_node_add_named_next_with_slot >> (vm=0x7fff96800740, node=696, name=0x7ffff7cc7c86 "l2-input", slot=2) >> at /home/pim/src/vpp/src/vlib/node.c:267 >> #7 0x00007ffff70d5ce5 in vnet_create_loopback_interface >> (sw_if_indexp=0x7fff515421e8, mac_address=0x7fff515421e2 "", is_specified=1 >> '\001', >> user_instance=0) at >> /home/pim/src/vpp/src/vnet/ethernet/interface.c:890 >> #8 0x00007ffff70d98df in create_simulated_ethernet_interfaces >> (vm=0x7fff96800740, input=0x7fff51542e40, cmd=0x7fff99b88088) >> at /home/pim/src/vpp/src/vnet/ethernet/interface.c:930 >> #9 0x00007ffff6e681d4 in vlib_cli_dispatch_sub_commands >> (vm=0x7fff96800740, cm=0x4312e0 <vlib_global_main+32>, >> input=0x7fff51542e40, >> parent_command_index=1146) at /home/pim/src/vpp/src/vlib/cli.c:592 >> #10 0x00007ffff6e67f4e in vlib_cli_dispatch_sub_commands >> (vm=0x7fff96800740, cm=0x4312e0 <vlib_global_main+32>, >> input=0x7fff51542e40, >> parent_command_index=33) at /home/pim/src/vpp/src/vlib/cli.c:549 >> #11 0x00007ffff6e67f4e in vlib_cli_dispatch_sub_commands >> (vm=0x7fff96800740, cm=0x4312e0 <vlib_global_main+32>, >> input=0x7fff51542e40, >> parent_command_index=0) at /home/pim/src/vpp/src/vlib/cli.c:549 >> #12 0x00007ffff6e66e98 in vlib_cli_input (vm=0x7fff96800740, >> input=0x7fff51542e40, function=0x7ffff6ef2c40 <unix_vlib_cli_output>, >> function_arg=0) >> at /home/pim/src/vpp/src/vlib/cli.c:695 >> #13 0x00007ffff6ef48dd in unix_cli_process_input (cm=0x7ffff6f69748 >> <unix_cli_main>, cli_file_index=0) at >> /home/pim/src/vpp/src/vlib/unix/cli.c:2617 >> #14 0x00007ffff6ef1cb1 in unix_cli_process (vm=0x7fff96800740, >> rt=0x7fff9bc4ea80, f=0x0) at /home/pim/src/vpp/src/vlib/unix/cli.c:2746 >> #15 0x00007ffff6e9f26d in vlib_process_bootstrap (_a=140735646532920) at >> /home/pim/src/vpp/src/vlib/main.c:1220 >> #16 0x00007ffff6d47e08 in clib_calljmp () at >> /home/pim/src/vpp/src/vppinfra/longjmp.S:123 >> #17 0x00007fff92380530 in ?? () >> #18 0x00007ffff6e9eb3f in vlib_process_startup (vm=0x1, p=0x8, >> f=0x7fff968008b0) at /home/pim/src/vpp/src/vlib/main.c:1245 >> #19 0x00007fff96800740 in ?? () >> #20 0x00007fff923805c0 in ?? () >> #21 0x00007ffff6eff104 in vlib_process_signal_event (vm=<error reading >> variable: Cannot access memory at address 0x2a7>, >> node_index=<error reading variable: Cannot access memory at address >> 0x29f>, >> type_opaque=<error reading variable: Cannot access memory at address >> 0x297>, >> data=<error reading variable: Cannot access memory at address 0x28f>) >> at /home/pim/src/vpp/src/vlib/node_funcs.h:1025 >> Backtrace stopped: previous frame inner to this frame (corrupt stack?) >> >> *2) Create bvi after loop:* >> DBGvpp# show version >> vpp v22.06-rc0~268-g4859d8d8e built by pim on hippo at 2022-03-23T19:23:53 >> DBGvpp# create loopback >> loop0 >> DBGvpp# delete loopback interface intfc loop0 >> DBGvpp# bvi create >> *0: /home/pim/src/vpp/src/vlib/node.c:194 (vlib_node_add_next_with_slot) >> assertion `slot == p[0]' fails >> * >> >> >> Thread 1 "vpp_main" received signal SIGABRT, Aborted. >> >> __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 >> >> >> 50 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory. >> >> (gdb) bt >> >> #0 __GI_raise (sig=sig@entry=6) at >> ../sysdeps/unix/sysv/linux/raise.c:50 >> >> #1 0x00007ffff69de859 in __GI_abort () at abort.c:79 >> >> #2 0x00000000004072f3 in os_panic () at >> /home/pim/src/vpp/src/vpp/vnet/main.c:413 >> >> #3 0x00007ffff6d2ebc9 in debugger () at >> /home/pim/src/vpp/src/vppinfra/error.c:84 >> >> #4 0x00007ffff6d2e92d in _clib_error (how_to_die=2, function_name=0x0, >> line_number=0, fmt=0x7ffff6f3b19c "%s:%d (%s) assertion `%s' fails") >> >> at /home/pim/src/vpp/src/vppinfra/error.c:143 >> >> #5 0x00007ffff6ea462b in vlib_node_add_next_with_slot >> (vm=0x7fff96800740, node_index=696, next_node_index=648, slot=0) >> >> at /home/pim/src/vpp/src/vlib/node.c:194 >> >> #6 0x00007ffff6ea61d8 in vlib_node_add_named_next_with_slot >> (vm=0x7fff96800740, node=696, name=0x7ffff7cc7c86 "l2-input", slot=0) >> >> at /home/pim/src/vpp/src/vlib/node.c:267 >> >> #7 0x00007ffff7123f69 in l2_bvi_create (user_instance=4294967295, >> mac_in=0x7fff515424e8, sw_if_indexp=0x7fff515424f8) >> >> at /home/pim/src/vpp/src/vnet/l2/l2_bvi.c:186 >> >> #8 0x00007ffff71266b9 in l2_bvi_create_cli (vm=0x7fff96800740, >> input=0x7fff51542e40, cmd=0x7fff99b87868) >> >> at /home/pim/src/vpp/src/vnet/l2/l2_bvi.c:256 >> >> #9 0x00007ffff6e681d4 in vlib_cli_dispatch_sub_commands >> (vm=0x7fff96800740, cm=0x4312e0 <vlib_global_main+32>, >> input=0x7fff51542e40, >> parent_command_index=1124) at /home/pim/src/vpp/src/vlib/cli.c:592 >> >> #10 0x00007ffff6e67f4e in vlib_cli_dispatch_sub_commands >> (vm=0x7fff96800740, cm=0x4312e0 <vlib_global_main+32>, >> input=0x7fff51542e40, >> parent_command_index=0) at /home/pim/src/vpp/src/vlib/cli.c:549 >> >> #11 0x00007ffff6e66e98 in vlib_cli_input (vm=0x7fff96800740, >> input=0x7fff51542e40, function=0x7ffff6ef2c40 <unix_vlib_cli_output>, >> function_arg=0) >> at /home/pim/src/vpp/src/vlib/cli.c:695 >> >> #12 0x00007ffff6ef48dd in unix_cli_process_input (cm=0x7ffff6f69748 >> <unix_cli_main>, cli_file_index=0) at >> /home/pim/src/vpp/src/vlib/unix/cli.c:2617 >> #13 0x00007ffff6ef1cb1 in unix_cli_process (vm=0x7fff96800740, >> rt=0x7fff9bc4ea80, f=0x0) at /home/pim/src/vpp/src/vlib/unix/cli.c:2746 >> >> #14 0x00007ffff6e9f26d in vlib_process_bootstrap (_a=140735646532920) at >> /home/pim/src/vpp/src/vlib/main.c:1220 >> #15 0x00007ffff6d47e08 in clib_calljmp () at >> /home/pim/src/vpp/src/vppinfra/longjmp.S:123 >> >> #16 0x00007fff92380530 in ?? () >> >> #17 0x00007ffff6e9eb3f in vlib_process_startup (vm=0x1, p=0x8, >> f=0x7fff968008b0) at /home/pim/src/vpp/src/vlib/main.c:1245 >> >> #18 0x00007fff96800740 in ?? () >> #19 0x00007fff923805c0 in ?? () >> #20 0x00007ffff6eff104 in vlib_process_signal_event (vm=<error reading >> variable: Cannot access memory at address 0x2a7>, >> node_index=<error reading variable: Cannot access memory at address >> 0x29f>, >> type_opaque=<error reading variable: Cannot access memory at address >> 0x297>, >> data=<error reading variable: Cannot access memory at address 0x28f>) >> at /home/pim/src/vpp/src/vlib/node_funcs.h:1025 >> Backtrace stopped: previous frame inner to this frame (corrupt stack?) >> >> -- >> Pim van Pelt <p...@ipng.nl> >> PBVP1-RIPE - http://www.ipng.nl/ >> >> >> >> > > -- > Best regards > Stanislav Zaikin > -- Pim van Pelt <p...@ipng.nl> PBVP1-RIPE - http://www.ipng.nl/
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