tools/testing/selftests/net/unicast_extensions.sh

   1 #!/bin/bash
   2 # SPDX-License-Identifier: GPL-2.0
   3 #
   4 # By Seth Schoen (c) 2021, for the IPv4 Unicast Extensions Project
   5 # Thanks to David Ahern for help and advice on nettest modifications.
   6 #
   7 # Self-tests for IPv4 address extensions: the kernel's ability to accept
   8 # certain traditionally unused or unallocated IPv4 addresses. For each kind
   9 # of address, we test for interface assignment, ping, TCP, and forwarding.
  10 # Must be run as root (to manipulate network namespaces and virtual
  11 # interfaces).
  12 #
  13 # Things we test for here:
  14 #
  15 # * Currently the kernel accepts addresses in 0/8 and 240/4 as valid.
  16 #
  17 # * Notwithstanding that, 0.0.0.0 and 255.255.255.255 cannot be assigned.
  18 #
  19 # * Currently the kernel DOES NOT accept unicast use of the lowest
  20 #   address in an IPv4 subnet (e.g. 192.168.100.0/32 in 192.168.100.0/24).
  21 #   This is treated as a second broadcast address, for compatibility
  22 #   with 4.2BSD (!).
  23 #
  24 # * Currently the kernel DOES NOT accept unicast use of any of 127/8.
  25 #
  26 # * Currently the kernel DOES NOT accept unicast use of any of 224/4.
  27 #
  28 # These tests provide an easy way to flip the expected result of any
  29 # of these behaviors for testing kernel patches that change them.
  30
  31 source lib.sh
  32
  33 check_gen_prog "nettest"
  34
  35 result=0
  36
  37 hide_output(){ exec 3>&1 4>&2 >/dev/null 2>/dev/null; }
  38 show_output(){ exec >&3 2>&4; }
  39
  40 show_result(){
  41         if [ $1 -eq 0 ]; then
  42                 printf "TEST: %-60s  [ OK ]\n" "${2}"
  43         else
  44                 printf "TEST: %-60s  [FAIL]\n" "${2}"
  45                 result=1
  46         fi
  47 }
  48
  49 _do_segmenttest(){
  50         # Perform a simple set of link tests between a pair of
  51         # IP addresses on a shared (virtual) segment, using
  52         # ping and nettest.
  53         # foo --- bar
  54         # Arguments: ip_a ip_b prefix_length test_description
  55         #
  56         # Caller must set up $foo_ns and $bar_ns namespaces
  57         # containing linked veth devices foo and bar,
  58         # respectively.
  59
  60         ip -n $foo_ns address add $1/$3 dev foo || return 1
  61         ip -n $foo_ns link set foo up || return 1
  62         ip -n $bar_ns address add $2/$3 dev bar || return 1
  63         ip -n $bar_ns link set bar up || return 1
  64
  65         ip netns exec $foo_ns timeout 2 ping -c 1 $2 || return 1
  66         ip netns exec $bar_ns timeout 2 ping -c 1 $1 || return 1
  67
  68         nettest -B -N $bar_ns -O $foo_ns -r $1 || return 1
  69         nettest -B -N $foo_ns -O $bar_ns -r $2 || return 1
  70
  71         return 0
  72 }
  73
  74 _do_route_test(){
  75         # Perform a simple set of gateway tests.
  76         #
  77         # [foo] <---> [foo1]-[bar1] <---> [bar]   /prefix
  78         #  host          gateway          host
  79         #
  80         # Arguments: foo_ip foo1_ip bar1_ip bar_ip prefix_len test_description
  81         # Displays test result and returns success or failure.
  82
  83         # Caller must set up $foo_ns, $bar_ns, and $router_ns
  84         # containing linked veth devices foo-foo1, bar1-bar
  85         # (foo in $foo_ns, foo1 and bar1 in $router_ns, and
  86         # bar in $bar_ns).
  87
  88         ip -n $foo_ns address add $1/$5 dev foo || return 1
  89         ip -n $foo_ns link set foo up || return 1
  90         ip -n $foo_ns route add default via $2 || return 1
  91         ip -n $bar_ns address add $4/$5 dev bar || return 1
  92         ip -n $bar_ns link set bar up || return 1
  93         ip -n $bar_ns route add default via $3 || return 1
  94         ip -n $router_ns address add $2/$5 dev foo1 || return 1
  95         ip -n $router_ns link set foo1 up || return 1
  96         ip -n $router_ns address add $3/$5 dev bar1 || return 1
  97         ip -n $router_ns link set bar1 up || return 1
  98
  99         echo 1 | ip netns exec $router_ns tee /proc/sys/net/ipv4/ip_forward
 100
 101         ip netns exec $foo_ns timeout 2 ping -c 1 $2 || return 1
 102         ip netns exec $foo_ns timeout 2 ping -c 1 $4 || return 1
 103         ip netns exec $bar_ns timeout 2 ping -c 1 $3 || return 1
 104         ip netns exec $bar_ns timeout 2 ping -c 1 $1 || return 1
 105
 106         nettest -B -N $bar_ns -O $foo_ns -r $1 || return 1
 107         nettest -B -N $foo_ns -O $bar_ns -r $4 || return 1
 108
 109         return 0
 110 }
 111
 112 segmenttest(){
 113         # Sets up veth link and tries to connect over it.
 114         # Arguments: ip_a ip_b prefix_len test_description
 115         hide_output
 116         setup_ns foo_ns bar_ns
 117         ip link add foo netns $foo_ns type veth peer name bar netns $bar_ns
 118
 119         test_result=0
 120         _do_segmenttest "$@" || test_result=1
 121
 122         ip netns pids $foo_ns | xargs -r kill -9
 123         ip netns pids $bar_ns | xargs -r kill -9
 124         cleanup_ns $foo_ns $bar_ns
 125         show_output
 126
 127         # inverted tests will expect failure instead of success
 128         [ -n "$expect_failure" ] && test_result=`expr 1 - $test_result`
 129
 130         show_result $test_result "$4"
 131 }
 132
 133 route_test(){
 134         # Sets up a simple gateway and tries to connect through it.
 135         # [foo] <---> [foo1]-[bar1] <---> [bar]   /prefix
 136         # Arguments: foo_ip foo1_ip bar1_ip bar_ip prefix_len test_description
 137         # Returns success or failure.
 138
 139         hide_output
 140         setup_ns foo_ns bar_ns router_ns
 141         ip link add foo netns $foo_ns type veth peer name foo1 netns $router_ns
 142         ip link add bar netns $bar_ns type veth peer name bar1 netns $router_ns
 143
 144         test_result=0
 145         _do_route_test "$@" || test_result=1
 146
 147         ip netns pids $foo_ns | xargs -r kill -9
 148         ip netns pids $bar_ns | xargs -r kill -9
 149         ip netns pids $router_ns | xargs -r kill -9
 150         cleanup_ns $foo_ns $bar_ns $router_ns
 151
 152         show_output
 153
 154         # inverted tests will expect failure instead of success
 155         [ -n "$expect_failure" ] && test_result=`expr 1 - $test_result`
 156         show_result $test_result "$6"
 157 }
 158
 159 echo "###########################################################################"
 160 echo "Unicast address extensions tests (behavior of reserved IPv4 addresses)"
 161 echo "###########################################################################"
 162 #
 163 # Test support for 240/4
 164 segmenttest 240.1.2.1   240.1.2.4    24 "assign and ping within 240/4 (1 of 2) (is allowed)"
 165 segmenttest 250.100.2.1 250.100.30.4 16 "assign and ping within 240/4 (2 of 2) (is allowed)"
 166 #
 167 # Test support for 0/8
 168 segmenttest 0.1.2.17    0.1.2.23  24 "assign and ping within 0/8 (1 of 2) (is allowed)"
 169 segmenttest 0.77.240.17 0.77.2.23 16 "assign and ping within 0/8 (2 of 2) (is allowed)"
 170 #
 171 # Even 255.255/16 is OK!
 172 segmenttest 255.255.3.1 255.255.50.77 16 "assign and ping inside 255.255/16 (is allowed)"
 173 #
 174 # Or 255.255.255/24
 175 segmenttest 255.255.255.1 255.255.255.254 24 "assign and ping inside 255.255.255/24 (is allowed)"
 176 #
 177 # Routing between different networks
 178 route_test 240.5.6.7 240.5.6.1  255.1.2.1    255.1.2.3      24 "route between 240.5.6/24 and 255.1.2/24 (is allowed)"
 179 route_test 0.200.6.7 0.200.38.1 245.99.101.1 245.99.200.111 16 "route between 0.200/16 and 245.99/16 (is allowed)"
 180 #
 181 # Test support for lowest address ending in .0
 182 segmenttest 5.10.15.20 5.10.15.0 24 "assign and ping lowest address (/24)"
 183 #
 184 # Test support for lowest address not ending in .0
 185 segmenttest 192.168.101.192 192.168.101.193 26 "assign and ping lowest address (/26)"
 186 #
 187 # Routing using lowest address as a gateway/endpoint
 188 route_test 192.168.42.1 192.168.42.0 9.8.7.6 9.8.7.0 24 "routing using lowest address"
 189 #
 190 # ==============================================
 191 # ==== TESTS THAT CURRENTLY EXPECT FAILURE =====
 192 # ==============================================
 193 expect_failure=true
 194 # It should still not be possible to use 0.0.0.0 or 255.255.255.255
 195 # as a unicast address.  Thus, these tests expect failure.
 196 segmenttest 0.0.1.5       0.0.0.0         16 "assigning 0.0.0.0 (is forbidden)"
 197 segmenttest 255.255.255.1 255.255.255.255 16 "assigning 255.255.255.255 (is forbidden)"
 198 #
 199 # Test support for not having all of 127 be loopback
 200 # Currently Linux does not allow this, so this should fail too
 201 segmenttest 127.99.4.5 127.99.4.6 16 "assign and ping inside 127/8 (is forbidden)"
 202 #
 203 # Test support for unicast use of class D
 204 # Currently Linux does not allow this, so this should fail too
 205 segmenttest 225.1.2.3 225.1.2.200 24 "assign and ping class D address (is forbidden)"
 206 #
 207 # Routing using class D as a gateway
 208 route_test 225.1.42.1 225.1.42.2 9.8.7.6 9.8.7.1 24 "routing using class D (is forbidden)"
 209 #
 210 # Routing using 127/8
 211 # Currently Linux does not allow this, so this should fail too
 212 route_test 127.99.2.3 127.99.2.4 200.1.2.3 200.1.2.4 24 "routing using 127/8 (is forbidden)"
 213 #
 214 unset expect_failure
 215 # =====================================================
 216 # ==== END OF TESTS THAT CURRENTLY EXPECT FAILURE =====
 217 # =====================================================
 218 exit ${result}