RFC 6810 and RFC 8210 specify that the "Max Length" value MUST NOT be
less than the Prefix Length element (underflow). On the other side,
overflow of the Max Length element also is possible, it being an 8-bit
unsigned integer allows for values larger than 32 or 128. This also
implicitly ensures there is no overflow of "Length" value.
When a PDU is received where the Max Length field is corrputed, the RTR
client (BIRD) should immediately terminate the session, flush all data
learned from that cache, and log an error for the operator.
Minor changes done by commiter.
Compare all IA_* flags that are set by sysdep iface code.
The old code ignores IA_SECONDARY flag when comparing whether iface
address updates from kernel changed anything. This is usually not an
issue as kernel removes all secondary addresses due to removal of the
primary one, but it breaks when sysctl 'promote_secondaries' is enabled
and kernel promotes secondary addresses to primary ones.
Thanks to 'Alexander' for the bugreport.
For convenience, Trie functions generally accept as input values not only
NET_IPx types of nets, but also NET_VPNx and NET_ROAx types. But returned
values are always NET_IPx types.
This feature is intended mostly for checking that BIRD's allocation
strategies don't consume much memory space. There are some cases where
withdrawing routes in a specific order lead to memory fragmentation and
this output should give the user at least a notion of how much memory is
actually used for data storage and how much memory is "just allocated"
or used for overhead.
Also raising the "system allocator overhead estimation" from 8 to 16
bytes; it is probably even more. I've found 16 as a local minimum in
best scenarios among reachable machines. I couldn't find any reasonable
method to estimate this value when BIRD starts up.
This commit also fixes the inaccurate computation of memory overhead for
slabs where the "system allocater overhead estimation" was improperly
added to the size of mmap-ed memory.
The prefix trie now supports longest-prefix-match query by function
trie_match_longest_ipX() and it can be extended to iteration over all
covering prefixes for a given prefix (from longest to shortest) using
TRIE_WALK_TO_ROOT_IPx() macro.
Trie walking allows enumeration of prefixes in a trie in the usual
lexicographic order. Optionally, trie enumeration can be restricted
to a chosen subnet (and its descendants).
BIRD implements shutdown by reconfiguring to fake empty configuration.
Such fake config structure is created from the last running config and
shares some data, including symbol table. This allows access to (removed)
routing tables and causes crash when 'show route' command is used during
shutdown.
Clean up symbol table, table list and links to default tables, so removed
routing tables cannot be accessed during shutdown.
We can also quite simply allocate bigger blocks. Anyway, we need these
blocks to be aligned to their size which needs one mmap() two times
bigger and then two munmap()s returning the unaligned parts.
The user can specify -B <N> on startup when <N> is the exponent of 2,
setting the block size to 2^N. On most systems, N is 12, anyway if you
know that your configuration is going to eat gigabytes of RAM, you are
almost forced to raise your block size as you may easily get into memory
fragmentation issues or you have to raise your maximum mapping count,
e.g. "sysctl vm.max_map_count=(number)".
Add trie tests intended as benchmarks that use external datasets
instead of generated prefixes. As datasets are not included, they
are commented out by default.
Use 16-way (4bit) branching in prefix trie instead of basic binary
branching. The change makes IPv4 prefix sets almost 3x faster, but
with more memory consumption and much more complicated algorithm.
Together with a previous filter change, it makes IPv4 prefix sets
about ~4.3x faster and slightly smaller (on my test data).
Pipes copy the original rte with old values, so they require rte to be
exported with stored tmpattrs. Other protocols access stored attributes
using eattr list, so they require rte to be exported with expanded
tmpattrs. This is temporary hack, we plan to remove whoe tmpattr mechanism.
Thanks to Paul Donohue for the bugreport.
In most cases of export there is no need to store back temporary
attributes to rte, as receivers (protocols) access eattr list anyway.
But pipe copies the original rte with old values, so we should store
tmpattrs also during export.
Thanks to Paul Donohue for the bugreport.
