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Daniel Mack says: ==================== bpf: add longest prefix match map This patch set adds a longest prefix match algorithm that can be used to match IP addresses to a stored set of ranges. It is exposed as a bpf map type. Internally, data is stored in an unbalanced tree of nodes that has a maximum height of n, where n is the prefixlen the trie was created with. Note that this has nothing to do with fib or fib6 and is in no way meant to replace or share code with it. It's rather a much simpler implementation that is specifically written with bpf maps in mind. Patch 1/2 adds the implementation, 2/2 an extensive test suite and 3/3 has benchmarking code for the new trie type. Feedback is much appreciated. Changelog: v3 -> v4: * David added a 3rd patch that augments map_perf_test for LPM trie benchmarks * Limit allocation of maps of this new type to CAP_SYS_ADMIN for now, as requested by Alexei * Add a stub .map_delete_elem so the core does not stumble over a NULL pointer when the syscall is invoked * Tests for non-power-of-2 prefix lengths were added * More comment style fixes v2 -> v3: * Store both the key match data and the caller provided value in the same byte array attached to a node. This avoids double allocations * Bring back node->flags to distinguish between 'real' and intermediate nodes * Fix comment style and some typos v1 -> v2: * Turn spin lock into raw spinlock * Lock with irqsave options during trie_update_elem() * Return -ENOMEM properly from trie_alloc() * Force attr->flags == BPF_F_NO_PREALLOC during creation * Set trie->map.pages after creation to account for map memory * Allow arbitrary value sizes * Removed node->flags and denode intermediate nodes through node->value == NULL instead rfc -> v1: * Add __rcu pointer annotations to make sparse happy * Fold _lpm_trie_find_target_node() into its only caller * Fix some minor documentation issues ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.