When classless static routes option is provided, then static routes
option should not be used. Hence, let's not mix and store them in one
storage.
This introduce sd_dhcp_lease_get_static_routes() and
sd_dhcp_lease_get_classless_routes().
The destination address was read twice, one is for prefixlen, and
other is for destination address itself. And for prefixlen, the address
might be read from unaligned buffer.
This also modernizes the code.
Otherwise, if the second push is failed, then the first hashmap contains
dirty entry.
Also, this makes hashmap_remove_value() used when removing leases to
make not wrong lease is removed from the hashmap.
Note, this just hide the root cause of the issue #22253, which will be
fixed in later commit.
Fixes#22253.
Turns out that part of systemd isn't covered by any fuzz targets and
that's not ideal considering that it parses data sent remotely. The
fuzzer triggers an infinite loop in lease_parse_routes as soon as it
starts so it seems to be working :-)
```
INFO: Running with entropic power schedule (0xFF, 100).
INFO: Seed: 23620602
INFO: Loaded 2 modules (182073 inline 8-bit counters): 176548 [0x7fdf511fc8d0, 0x7fdf51227a74), 5525 [0x5f6ef0, 0x5f8485),
INFO: Loaded 2 PC tables (182073 PCs): 176548 [0x7fdf51227a78,0x7fdf514d94b8), 5525 [0x5f8488,0x60ddd8),
./build/fuzz-dhcp-client: Running 1 inputs 1 time(s) each.
Running: test/fuzz/fuzz-dhcp-client/timeout-ed34161922c7075c4773f2ada3dee8685d220980
ALARM: working on the last Unit for 31 seconds
and the timeout value is 30 (use -timeout=N to change)
==80731== ERROR: libFuzzer: timeout after 31 seconds
#0 0x51b32e in __sanitizer_print_stack_trace (/home/vagrant/systemd/build/fuzz-dhcp-client+0x51b32e)
#1 0x4689e9 in fuzzer::PrintStackTrace() (/home/vagrant/systemd/build/fuzz-dhcp-client+0x4689e9)
#2 0x44a0f4 in fuzzer::Fuzzer::StaticAlarmCallback() (/home/vagrant/systemd/build/fuzz-dhcp-client+0x44a0f4)
#3 0x7fdf4f8b474f (/lib64/libc.so.6+0x4274f)
#4 0x465fee in __sanitizer_cov_trace_const_cmp4 (/home/vagrant/systemd/build/fuzz-dhcp-client+0x465fee)
#5 0x57eee5 in lease_parse_routes /home/vagrant/systemd/build/../src/libsystemd-network/sd-dhcp-lease.c:495:23
#6 0x57baf3 in dhcp_lease_parse_options /home/vagrant/systemd/build/../src/libsystemd-network/sd-dhcp-lease.c:701:21
#7 0x572450 in parse_options /home/vagrant/systemd/build/../src/libsystemd-network/dhcp-option.c:348:33
#8 0x571cea in dhcp_option_parse /home/vagrant/systemd/build/../src/libsystemd-network/dhcp-option.c:381:21
#9 0x559a01 in client_handle_offer /home/vagrant/systemd/build/../src/libsystemd-network/sd-dhcp-client.c:1543:13
#10 0x5592bd in LLVMFuzzerTestOneInput /home/vagrant/systemd/build/../src/libsystemd-network/fuzz-dhcp-client.c:78:9
#11 0x44a379 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) (/home/vagrant/systemd/build/fuzz-dhcp-client+0x44a379)
#12 0x42ae1f in fuzzer::RunOneTest(fuzzer::Fuzzer*, char const*, unsigned long) (/home/vagrant/systemd/build/fuzz-dhcp-client+0x42ae1f)
#13 0x432ade in fuzzer::FuzzerDriver(int*, char***, int (*)(unsigned char const*, unsigned long)) (/home/vagrant/systemd/build/fuzz-dhcp-client+0x432ade)
#14 0x421f86 in main (/home/vagrant/systemd/build/fuzz-dhcp-client+0x421f86)
#15 0x7fdf4f89f55f in __libc_start_call_main (/lib64/libc.so.6+0x2d55f)
#16 0x7fdf4f89f60b in __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x2d60b)
#17 0x421fd4 in _start (/home/vagrant/systemd/build/fuzz-dhcp-client+0x421fd4)
SUMMARY: libFuzzer: timeout
```
The block try to find and remove the existing static lease which matches
the provided client ID, and the provided client ID will not be stored
anywhere. Hence, it is not necessary to duplicate it.
The commit b89a3758e9 made the validity
check of the received message stricter. E.g. if the client received a
message with broken NTP server option, then the entire message is
dropped.
This relaxes the check. If some non-critical options are broken, then
ignore the options, but the message itself is still accepted.
Fixes#22099.
Yu Watanabe
Evgeny Vereshchagin
Jan Janssen