```
=220358== Invalid read of size 8
==220358== at 0x452F05: l2tp_session_free (l2tp-tunnel.c:46)
==220358== by 0x456926: l2tp_tunnel_done (l2tp-tunnel.c:725)
==220358== by 0x43CF4D: netdev_free (netdev.c:205)
==220358== by 0x43D045: netdev_unref (netdev.c:210)
==220358== by 0x4198B7: manager_free (networkd-manager.c:1877)
==220358== by 0x40D0B3: manager_freep (networkd-manager.h:105)
==220358== by 0x40DE1C: run (networkd.c:21)
==220358== by 0x40DE75: main (networkd.c:130)
==220358== Address 0x5c035d0 is 0 bytes inside a block of size 40 free'd
==220358== at 0x483A9F5: free (vg_replace_malloc.c:538)
==220358== by 0x452F87: l2tp_session_free (l2tp-tunnel.c:57)
==220358== by 0x456857: netdev_l2tp_tunnel_verify (l2tp-tunnel.c:710)
==220358== by 0x440947: netdev_load_one (netdev.c:738)
==220358== by 0x441222: netdev_load (netdev.c:851)
==220358== by 0x419C50: manager_load_config (networkd-manager.c:1934)
==220358== by 0x40D7BE: run (networkd.c:87)
==220358== by 0x40DE75: main (networkd.c:130)
==220358== Block was alloc'd at
==220358== at 0x4839809: malloc (vg_replace_malloc.c:307)
==220358== by 0x452A76: malloc_multiply (alloc-util.h:96)
==220358== by 0x4531E6: l2tp_session_new_static (l2tp-tunnel.c:82)
==220358== by 0x455C01: config_parse_l2tp_session_id (l2tp-tunnel.c:535)
==220358== by 0x48E6D72: next_assignment (conf-parser.c:133)
==220358== by 0x48E77A3: parse_line (conf-parser.c:271)
==220358== by 0x48E7E4F: config_parse (conf-parser.c:396)
==220358== by 0x48E80E5: config_parse_many_files (conf-parser.c:453)
==220358== by 0x48E8490: config_parse_many (conf-parser.c:512)
==220358== by 0x44089C: netdev_load_one (netdev.c:729)
==220358== by 0x441222: netdev_load (netdev.c:851)
==220358== by 0x419C50: manager_load_config (networkd-manager.c:1934)
```
Prompted by the discussions in #15180.
This is a bit more complex than I hoped, since for PID 1 we need to pass
in the synethetic environment block in we generate on demand.
Builds with recent glibc would fail with:
../src/network/netdev/fou-tunnel.c: In function ‘config_parse_ip_protocol’:
../src/basic/macro.h:380:9: error: static assertion failed: "IPPROTO_MAX-1 <= UINT8_MAX"
380 | static_assert(expr, #expr)
| ^~~~~~~~~~~~~
../src/network/netdev/fou-tunnel.c:161:9: note: in expansion of macro ‘assert_cc’
161 | assert_cc(IPPROTO_MAX-1 <= UINT8_MAX);
| ^~~~~~~~~
This is because f9ac84f92f151e07586c55e14ed628d493a5929d (present in
glibc-2.31.9000-9.fc33.x86_64) added IPPROTO_MPTCP=262, following
v5.5-rc5-1002-gfaf391c382 in the kernel.
Intermediate Functional Block
The Intermediate Functional Block (ifb) pseudo network interface acts as a QoS concentrator for multiple different sources of traffic. Packets from or to other interfaces have to be redirected to it using the mirred action in order to be handled, regularly routed traffic will be dropped. This way, a single stack of qdiscs, classes and filters can be shared between multiple interfaces.
Here's a simple example to feed incoming traffic from multiple interfaces through a Stochastic Fairness Queue (sfq):
(1) # modprobe ifb
(2) # ip link set ifb0 up
(3) # tc qdisc add dev ifb0 root sfq
let's add [static] where it was missing so far
Drop [static] on parameters that can be NULL.
Add an assert() around parameters that have [static] and can't be NULL
hence.
Add some "const" where it was forgotten.
Susant Sahani
Yu Watanabe
Lennart Poettering
Rubens Figueiredo
Benjamin Robin
Zbigniew Jędrzejewski-Szmek
1848
Susant Sahani