Relax rtsock message restrictions

[melifaro]

Summary

Address multiple issues with strict rtsock message validation.

D28668 "normalisation" approach was based on the assumption that we always have at least "standard".
It turned out to be false - certain older applications like quagga or routed abuse sin[6]_len field and set it to the offset to the first fully-zero bit in the mask. It is impossible to normalize such sockaddrs without reallocation.

With that in mind, change the approach to use a distinct memory buffer for the altered sockaddrs.
This allows supporting the older software while maintaining the guarantee on the "standard" sockaddrs.

Test Plan

bird2-2.0.7

Configs:

protocol static random_s4 {
        disabled;
        ipv4 { export all; };
        route 11.0.0.0/24 blackhole;
        route 11.0.1.0/24 unreachable;
#        route 11.0.2.0/24 prohibit;
        route 11.0.3.0/24 via 10.0.0.9;
#       route 11.0.4.0/24 via 10.0.0.8;
        route 11.0.5.0/24 via "vtnet0";
}

protocol static random_s6 {
        disabled;
        ipv6 { export all; };
        route 2a02:6b8:0:1::/64 blackhole;
        route 2a02:6b8:0:2::/64 unreachable;
        route 2a02:6b8:0:3::/64 via fe80::333%vtnet0;
#       route 2a02:6b8:0:4::/64 via fe80::5054:ff:fe14:e319%vtnet0;
        route 2a02:6b8:0:5::/64 via "vtnet0";
}

Output:

2021-04-18 20:42:37.019 <INFO> Enabling protocol random_s4
2021-04-18 20:42:37.019 <TRACE> random_s4: Starting
2021-04-18 20:42:37.019 <TRACE> random_s4: State changed to up
2021-04-18 20:42:37.019 <TRACE> random_s4 > added [best] 11.0.0.0/24 blackhole
2021-04-18 20:42:37.019 <TRACE> kernel1 < added 11.0.0.0/24 blackhole
2021-04-18 20:42:37.019 <TRACE> random_s4 > added [best] 11.0.1.0/24 unreachable
2021-04-18 20:42:37.019 <TRACE> kernel1 < added 11.0.1.0/24 unreachable
2021-04-18 20:42:37.019 <TRACE> random_s4 > added [best] 11.0.2.0/24 prohibited
2021-04-18 20:42:37.019 <TRACE> kernel1 < rejected by protocol 11.0.2.0/24 prohibited
2021-04-18 20:42:37.019 <TRACE> random_s4 > added [best] 11.0.3.0/24 unicast
2021-04-18 20:42:37.019 <TRACE> kernel1 < added 11.0.3.0/24 unicast
2021-04-18 20:42:37.019 <TRACE> random_s4 > added [best] 11.0.5.0/24 unicast
2021-04-18 20:42:37.019 <TRACE> kernel1 < added 11.0.5.0/24 unicast
2021-04-18 20:42:38.234 <INFO> Enabling protocol random_s6
2021-04-18 20:42:38.234 <TRACE> random_s6: Starting
2021-04-18 20:42:38.234 <TRACE> random_s6: State changed to up
2021-04-18 20:42:38.234 <TRACE> random_s6 > added [best] 2a02:6b8:0:1::/64 blackhole
2021-04-18 20:42:38.234 <TRACE> kernel2 < added 2a02:6b8:0:1::/64 blackhole
2021-04-18 20:42:38.234 <TRACE> random_s6 > added [best] 2a02:6b8:0:2::/64 unreachable
2021-04-18 20:42:38.234 <TRACE> kernel2 < added 2a02:6b8:0:2::/64 unreachable
2021-04-18 20:42:38.234 <TRACE> random_s6 > added [best] 2a02:6b8:0:3::/64 unicast
2021-04-18 20:42:38.234 <TRACE> kernel2 < added 2a02:6b8:0:3::/64 unicast
2021-04-18 20:42:38.234 <TRACE> random_s6 > added [best] 2a02:6b8:0:5::/64 unicast
2021-04-18 20:42:38.234 <TRACE> kernel2 < added 2a02:6b8:0:5::/64 unicast
2021-04-18 20:42:38.234 <TRACE> random_s6 > added [best] 2a02:6b8:0:6::/64 unicast
2021-04-18 20:42:38.234 <TRACE> kernel2 < added 2a02:6b8:0:6::/64 unicast


20:40 [0] m@devel2 netstat -4rnW | grep 11.0
11.0.0.0/24        127.0.0.1          UG1B        5  16384        lo0
11.0.1.0/24        127.0.0.1          UGR1        6  16384        lo0
11.0.3.0/24        10.0.0.9           UG1         7   1500     vtnet0
11.0.5.0/24        link#1             U1          8   1500     vtnet0

20:40 [0] m@devel2 netstat -4onW
Nexthop data

Internet:
Idx   Type         IFA                Gateway             Flags      Use Mtu         Netif     Addrif Refcnt Prepend
1       v4/resolve 127.0.0.1          lo0/resolve        H         81858  16384        lo0               2
2       v4/resolve 10.0.0.8           vtnet0/resolve                  53   1500     vtnet0               2
3       v4/resolve 127.0.0.1          lo0/resolve        HS            0  16384        lo0    vtnet0     2
4            v4/gw 10.0.0.8           10.0.0.1           GS           41   1500     vtnet0               2
5            v4/gw 127.0.0.1          127.0.0.1          G1B           0  16384        lo0               2
6            v4/gw 127.0.0.1          127.0.0.1          GR1           0  16384        lo0               2
7            v4/gw 10.0.0.8           10.0.0.9           G1            0   1500     vtnet0               2
8       v4/resolve 10.0.0.8           vtnet0/resolve     1             0   1500     vtnet0               2

//

20:41 [0] m@devel2 netstat -6rnW | grep 2a02:6b
2a02:6b8:0:1::/64                 ::1                           UG1B        8  16384      lo0
2a02:6b8:0:2::/64                 ::1                           UGR1        9  16384      lo0
2a02:6b8:0:3::/64                 fe80::333%vtnet0              UG1        10   1500   vtnet0
2a02:6b8:0:5::/64                 link#1                        U1         11   1500   vtnet0
2a02:6b8:0:6::/64                 2a01:4f8:13a:70c:ffff::66     UG1        12   1500   vtnet0
20:42 [0] m@devel2 netstat -6onW
Nexthop data

Internet6:
Idx   Type         IFA                           Gateway                        Flags      Use Mtu       Netif   Addrif Refcnt Prepend
1       v6/resolve ::1                           lo0/resolve                   HS        81883  16384      lo0             2
2       v6/resolve fe80::1%lo0                   lo0/resolve                   HS            0  16384      lo0             2
3       v6/resolve fe80::1%lo0                   lo0/resolve                                 0  16384      lo0             2
4       v6/resolve ::1                           lo0/resolve                   HS            0  16384      lo0  vtnet0     3
5       v6/resolve fe80::5054:ff:fe14:e319%vtnet0 vtnet0/resolve                             0   1500   vtnet0             3
6            v6/gw ::1                           ::1                           GRS           0  16384      lo0             5
7            v6/gw 2a01:4f8:13a:70c:ffff::8      2a01:4f8:13a:70c:ffff::1      GS         7709   1500   vtnet0             5
8            v6/gw ::1                           ::1                           G1B           0  16384      lo0             2
9            v6/gw ::1                           ::1                           GR1           0  16384      lo0             2
10           v6/gw fe80::5054:ff:fe14:e319%vtnet0 fe80::333%vtnet0             G1            0   1500   vtnet0             2
11      v6/resolve fe80::5054:ff:fe14:e319%vtnet0 vtnet0/resolve               1             0   1500   vtnet0             2
12           v6/gw 2a01:4f8:13a:70c:ffff::8      2a01:4f8:13a:70c:ffff::66     G1            0   1500   vtnet0             2

FRR

FRR 7.5.1_1

Configs

ip route 11.0.0.0/24 blackhole
ip route 11.0.1.0/24 reject
ip route 11.0.3.0/24 10.0.0.9
ip route 11.0.5.0/24 vtnet0
ipv6 route 2a02:6b8:0:1::/64 blackhole
ipv6 route 2a02:6b8:0:2::/64 reject
ipv6 route 2a02:6b8:0:3::/64 fe80::333 vtnet0
ipv6 route 2a02:6b8:0:5::/64 vtnet0
ipv6 route 2a02:6b8:0:6::/64 2a01:4f8:13a:70c:ffff::66

Output

20:24 [0] m@devel2 netstat -4rnW
Routing tables

Internet:
Destination        Gateway            Flags   Nhop#    Mtu      Netif Expire
default            10.0.0.1           UGS         4   1500     vtnet0
10.0.0.0/24        link#1             U           2   1500     vtnet0
10.0.0.8           link#1             UHS         3  16384        lo0
11.0.0.0/24        127.0.0.1          UG1B        5  16384        lo0
11.0.1.0/24        127.0.0.1          UGR1        6  16384        lo0
11.0.3.0/24        10.0.0.9           UG1         7   1500     vtnet0
11.0.5.0/24        link#1             U1          8   1500     vtnet0
127.0.0.1          link#2             UH          1  16384        lo0
20:24 [0] m@devel2 netstat -4onW
Nexthop data

Internet:
Idx   Type         IFA                Gateway             Flags      Use Mtu         Netif     Addrif Refcnt Prepend
1       v4/resolve 127.0.0.1          lo0/resolve        H         81858  16384        lo0               2
2       v4/resolve 10.0.0.8           vtnet0/resolve                   9   1500     vtnet0               3
3       v4/resolve 127.0.0.1          lo0/resolve        HS            0  16384        lo0    vtnet0     2
4            v4/gw 10.0.0.8           10.0.0.1           GS           37   1500     vtnet0               2
5            v4/gw 127.0.0.1          127.0.0.1          G1B           0  16384        lo0               2
6            v4/gw 127.0.0.1          127.0.0.1          GR1           0  16384        lo0               2
7            v4/gw 10.0.0.8           10.0.0.9           G1            0   1500     vtnet0               2
8       v4/resolve 10.0.0.8           vtnet0/resolve     1             0   1500     vtnet0               2

//

20:36 [0] m@devel2 netstat -6rnW | grep 2a02:6b8
2a02:6b8:0:1::/64                 ::1                           UG1B        8  16384      lo0
2a02:6b8:0:2::/64                 ::1                           UGR1        9  16384      lo0
2a02:6b8:0:3::/64                 fe80::333%vtnet0              UG1        12   1500   vtnet0
2a02:6b8:0:5::/64                 link#1                        U1         10   1500   vtnet0
2a02:6b8:0:6::/64                 2a01:4f8:13a:70c:ffff::66     UG1        11   1500   vtnet0
20:38 [0] m@devel2 netstat -6onW
Nexthop data

Internet6:
Idx   Type         IFA                           Gateway                        Flags      Use Mtu       Netif   Addrif Refcnt Prepend
1       v6/resolve ::1                           lo0/resolve                   HS        81883  16384      lo0             2
2       v6/resolve fe80::1%lo0                   lo0/resolve                   HS            0  16384      lo0             2
3       v6/resolve fe80::1%lo0                   lo0/resolve                                 0  16384      lo0             2
4       v6/resolve ::1                           lo0/resolve                   HS            0  16384      lo0  vtnet0     3
5       v6/resolve fe80::5054:ff:fe14:e319%vtnet0 vtnet0/resolve                             0   1500   vtnet0             3
6            v6/gw ::1                           ::1                           GRS           0  16384      lo0             5
7            v6/gw 2a01:4f8:13a:70c:ffff::8      2a01:4f8:13a:70c:ffff::1      GS         7061   1500   vtnet0             5
8            v6/gw ::1                           ::1                           G1B           0  16384      lo0             2
9            v6/gw ::1                           ::1                           GR1           0  16384      lo0             2
10      v6/resolve fe80::5054:ff:fe14:e319%vtnet0 vtnet0/resolve               1             0   1500   vtnet0             2
11           v6/gw 2a01:4f8:13a:70c:ffff::8      2a01:4f8:13a:70c:ffff::66     G1            0   1500   vtnet0             2
12           v6/gw fe80::5054:ff:fe14:e319%vtnet0 fe80::333%vtnet0             G1            0   1500   vtnet0             2

Quagga 1.2.4

Config

ip route 11.0.0.0/24 Null0
ip route 11.0.1.0/24 lo0 reject
ip route 11.0.3.0/24 10.0.0.9
ip route 11.0.5.0/24 vtnet0
ipv6 route 2a02:6b8:0:1::/64 lo0 blackhole
ipv6 route 2a02:6b8:0:2::/64 lo0 reject
ipv6 route 2a02:6b8:0:3::/64 fe80::333 vtnet0
ipv6 route 2a02:6b8:0:5::/64 vtnet0
ipv6 route 2a02:6b8:0:6::/64 2a01:4f8:13a:70c:ffff::66

21:49 [0] m@devel2 netstat -4rnW | grep 11.0
11.0.0.0/24        127.0.0.1          UG1B        5  16384        lo0
11.0.1.0/24        127.0.0.1          UGR1        8  16384        lo0
11.0.3.0/24        10.0.0.9           UG1         6   1500     vtnet0
11.0.5.0/24        link#1             U1          7   1500     vtnet0
21:49 [0] m@devel2 netstat -4onW
Nexthop data

Internet:
Idx   Type         IFA                Gateway             Flags      Use Mtu         Netif     Addrif Refcnt Prepend
1       v4/resolve 127.0.0.1          lo0/resolve        H             0  16384        lo0               2
2       v4/resolve 10.0.0.8           vtnet0/resolve                 104   1500     vtnet0              16
3       v4/resolve 127.0.0.1          lo0/resolve        HS            0  16384        lo0    vtnet0     2
4            v4/gw 10.0.0.8           10.0.0.1           GS           15   1500     vtnet0               2
5            v4/gw 127.0.0.1          127.0.0.1          G1B           0  16384        lo0               2
6            v4/gw 10.0.0.8           10.0.0.9           G1            0   1500     vtnet0               2
7       v4/resolve 10.0.0.8           vtnet0/resolve     1             0   1500     vtnet0               2
8            v4/gw 127.0.0.1          127.0.0.1          GR1           0  16384        lo0               2

21:46 [0] m@devel2 netstat -6rnW | grep ^2a02
2a02:6b8:0:1::/64                 ::1                           UG1B       11  16384      lo0
2a02:6b8:0:2::/64                 ::1                           UGR1       12  16384      lo0
2a02:6b8:0:3::/64                 fe80::333%vtnet0              UG1         8   1500   vtnet0
2a02:6b8:0:5::/64                 link#1                        U1          9   1500   vtnet0
2a02:6b8:0:6::/64                 2a01:4f8:13a:70c:ffff::66     UG1        10   1500   vtnet0
21:46 [0] m@devel2 netstat -6onW
Nexthop data

Internet6:
Idx   Type         IFA                           Gateway                        Flags      Use Mtu       Netif   Addrif Refcnt Prepend
1       v6/resolve ::1                           lo0/resolve                   HS            0  16384      lo0             2
2       v6/resolve fe80::1%lo0                   lo0/resolve                   HS            0  16384      lo0             2
3       v6/resolve fe80::1%lo0                   lo0/resolve                                 0  16384      lo0             2
4       v6/resolve ::1                           lo0/resolve                   HS            0  16384      lo0  vtnet0     3
5       v6/resolve fe80::5054:ff:fe14:e319%vtnet0 vtnet0/resolve                             0   1500   vtnet0             3
6            v6/gw ::1                           ::1                           GRS           0  16384      lo0             5
7            v6/gw 2a01:4f8:13a:70c:ffff::8      2a01:4f8:13a:70c:ffff::1      GS          752   1500   vtnet0             5
8            v6/gw fe80::5054:ff:fe14:e319%vtnet0 fe80::333%vtnet0             G1            0   1500   vtnet0             2
9       v6/resolve fe80::5054:ff:fe14:e319%vtnet0 vtnet0/resolve               1             0   1500   vtnet0             2
10           v6/gw 2a01:4f8:13a:70c:ffff::8      2a01:4f8:13a:70c:ffff::66     G1            0   1500   vtnet0             2
11           v6/gw ::1                           ::1                           G1B           0  16384      lo0             2
12           v6/gw ::1                           ::1                           GR1           0  16384      lo0             2

routed

-- 20:59:50 --
last discovered router 10.0.0.157 via vtnet0 is bad--re-solicit
turn off Router Discovery client
Chg    0.0.0.0         -->10.0.0.157       metric=15 vtnet0 <RDISC>
                                           metric=16 <>
Del #1 10.0.0.0 (mask 0xffffff00)-->10.0.0.157 metric=1  vtnet0 20:59:11
Chg    11.0.0.0 (mask 0xffffff00)-->10.0.0.157 metric=1  vtnet0 20:59:11
                                           metric=16 20:56:50
-- 20:59:57 --
Del    0.0.0.0         -->10.0.0.157       metric=16 vtnet0 20:55:50
-- 20:59:57 --
turn on Router Discovery client using 10.0.0.157 via vtnet0
Add    0.0.0.0         -->10.0.0.157       metric=15 vtnet0 <RDISC>

21:00 [0] m@devel2 netstat -4rnW | grep 10.0.0.157
default            10.0.0.157         UG          4   1500     vtnet0
11.0.0.0/24        10.0.0.157         UG          5   1500     vtnet0


21:01 [0] m@devel2 netstat -4onW
Nexthop data

Internet:
Idx   Type         IFA                Gateway             Flags      Use Mtu         Netif     Addrif Refcnt Prepend
1       v4/resolve 127.0.0.1          lo0/resolve        H           134  16384        lo0               2
2       v4/resolve 10.0.0.8           vtnet0/resolve                   8   1500     vtnet0               2
3       v4/resolve 127.0.0.1          lo0/resolve        HS            0  16384        lo0    vtnet0     2
4            v4/gw 10.0.0.8           10.0.0.157         G             0   1500     vtnet0               2
5            v4/gw 10.0.0.8           10.0.0.157         G             0   1500     vtnet0               2

Routing tests:

21:12 [1] m@devel2 s kyua test -k /usr/tests/sys/net/routing/Kyuafile
test_rtsock_l3:rtm_add_v4_gu_ifa_ordered_success  ->  passed  [0.124s]
test_rtsock_l3:rtm_add_v4_gw_direct_success  ->  passed  [0.116s]
test_rtsock_l3:rtm_add_v4_no_rtf_host_failure  ->  failed: 1 checks failed; see output for more details  [0.119s]
test_rtsock_l3:rtm_add_v4_temporal1_success  ->  passed  [0.118s]
test_rtsock_l3:rtm_add_v6_gu_gw_gu_direct_success  ->  passed  [0.118s]
test_rtsock_l3:rtm_add_v6_gu_ifa_hostroute_success  ->  passed  [0.117s]
test_rtsock_l3:rtm_add_v6_gu_ifa_ordered_success  ->  passed  [0.121s]
test_rtsock_l3:rtm_add_v6_gu_ifa_prefixroute_success  ->  passed  [0.118s]
test_rtsock_l3:rtm_add_v6_temporal1_success  ->  passed  [0.119s]
test_rtsock_l3:rtm_change_v4_flags_success  ->  passed  [0.120s]
test_rtsock_l3:rtm_change_v4_gw_success  ->  passed  [0.124s]
test_rtsock_l3:rtm_change_v4_mtu_success  ->  passed  [0.120s]
test_rtsock_l3:rtm_change_v6_flags_success  ->  passed  [0.120s]
test_rtsock_l3:rtm_change_v6_gw_success  ->  passed  [0.128s]
test_rtsock_l3:rtm_change_v6_mtu_success  ->  passed  [0.115s]
test_rtsock_l3:rtm_del_v4_gu_ifa_prefixroute_success  ->  passed  [0.121s]
test_rtsock_l3:rtm_del_v4_prefix_nogw_success  ->  passed  [0.118s]
test_rtsock_l3:rtm_del_v6_gu_ifa_hostroute_success  ->  passed  [0.120s]
test_rtsock_l3:rtm_del_v6_gu_ifa_prefixroute_success  ->  passed  [0.121s]
test_rtsock_l3:rtm_del_v6_gu_prefix_nogw_success  ->  passed  [0.116s]
test_rtsock_l3:rtm_get_v4_empty_dst_failure  ->  passed  [0.003s]
test_rtsock_l3:rtm_get_v4_exact_success  ->  passed  [0.129s]
test_rtsock_l3:rtm_get_v4_hostbits_failure  ->  failed: 1 checks failed; see output for more details  [0.118s]
test_rtsock_l3:rtm_get_v4_lpm_success  ->  passed  [0.116s]
test_rtsock_lladdr:rtm_add_v4_gu_lle_success  ->  passed  [0.118s]
test_rtsock_lladdr:rtm_add_v6_gu_lle_success  ->  passed  [0.119s]
test_rtsock_lladdr:rtm_add_v6_ll_lle_success  ->  passed  [0.115s]
test_rtsock_lladdr:rtm_del_v4_gu_lle_success  ->  passed  [0.116s]
test_rtsock_lladdr:rtm_del_v6_gu_lle_success  ->  passed  [0.114s]
test_rtsock_lladdr:rtm_del_v6_ll_lle_success  ->  passed  [0.116s]

Results file id is usr_tests_sys_net_routing.20210420-211213-600214
Results saved to /home/melifaro/.kyua/store/results.usr_tests_sys_net_routing.20210420-211213-600214.db

28/30 passed (2 failed)

hostbits test failures are not relevafnt here

[melifaro]

Fix quagga.

[melifaro]

Reflect committed changes.