bcc: add support for lpm trie map type

src/cc/compat/linux/bpf.h

@@ -63,6 +63,12 @@ struct bpf_insn {
 	__s32	imm;		/* signed immediate constant */
 };
 
+/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
+struct bpf_lpm_trie_key {
+	__u32	prefixlen;	/* up to 32 for AF_INET, 128 for AF_INET6 */
+	__u8	data[0];	/* Arbitrary size */
+};
+
 /* BPF syscall commands, see bpf(2) man-page for details. */
 enum bpf_cmd {
 	BPF_MAP_CREATE,
@@ -89,6 +95,7 @@ enum bpf_map_type {
 	BPF_MAP_TYPE_CGROUP_ARRAY,
 	BPF_MAP_TYPE_LRU_HASH,
 	BPF_MAP_TYPE_LRU_PERCPU_HASH,
+	BPF_MAP_TYPE_LPM_TRIE,
 };
 
 enum bpf_prog_type {

src/cc/compat/linux/virtual_bpf.h

@@ -64,6 +64,12 @@ struct bpf_insn {
 	__s32	imm;		/* signed immediate constant */
 };
 
+/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
+struct bpf_lpm_trie_key {
+	__u32	prefixlen;	/* up to 32 for AF_INET, 128 for AF_INET6 */
+	__u8	data[0];	/* Arbitrary size */
+};
+
 /* BPF syscall commands, see bpf(2) man-page for details. */
 enum bpf_cmd {
 	BPF_MAP_CREATE,
@@ -90,6 +96,7 @@ enum bpf_map_type {
 	BPF_MAP_TYPE_CGROUP_ARRAY,
 	BPF_MAP_TYPE_LRU_HASH,
 	BPF_MAP_TYPE_LRU_PERCPU_HASH,
+	BPF_MAP_TYPE_LPM_TRIE,
 };
 
 enum bpf_prog_type {

src/cc/frontends/clang/b_frontend_action.cc

@@ -645,6 +645,8 @@ bool BTypeVisitor::VisitVarDecl(VarDecl *Decl) {
       map_type = BPF_MAP_TYPE_LRU_HASH;
     } else if (A->getName() == "maps/lru_percpu_hash") {
       map_type = BPF_MAP_TYPE_LRU_PERCPU_HASH;
+    } else if (A->getName() == "maps/lpm_trie") {
+      map_type = BPF_MAP_TYPE_LPM_TRIE;
     } else if (A->getName() == "maps/histogram") {
       if (table.key_desc == "\"int\"")
         map_type = BPF_MAP_TYPE_ARRAY;

src/lua/bcc/table.lua

@@ -29,6 +29,7 @@ BaseTable.static.BPF_MAP_TYPE_STACK_TRACE = 7
 BaseTable.static.BPF_MAP_TYPE_CGROUP_ARRAY = 8
 BaseTable.static.BPF_MAP_TYPE_LRU_HASH = 9
 BaseTable.static.BPF_MAP_TYPE_LRU_PERCPU_HASH = 10
+BaseTable.static.BPF_MAP_TYPE_LPM_TRIE = 11
 
 function BaseTable:initialize(t_type, bpf, map_id, map_fd, key_type, leaf_type)
   assert(t_type == libbcc.bpf_table_type_id(bpf.module, map_id))

src/lua/bpf/cdef.lua

@@ -140,6 +140,7 @@ else
 		S.c.BPF_MAP.CGROUP_ARRAY = 8
 		S.c.BPF_MAP.LRU_HASH     = 9
 		S.c.BPF_MAP.LRU_PERCPU_HASH = 10
+		S.c.BPF_MAP.LPM_TRIE     = 11
 	end
 	if not S.c.BPF_PROG.TRACEPOINT then
 		S.c.BPF_PROG.TRACEPOINT  = 5

src/python/bcc/table.py

@@ -34,6 +34,7 @@ BPF_MAP_TYPE_STACK_TRACE = 7
 BPF_MAP_TYPE_CGROUP_ARRAY = 8
 BPF_MAP_TYPE_LRU_HASH = 9
 BPF_MAP_TYPE_LRU_PERCPU_HASH = 10
+BPF_MAP_TYPE_LPM_TRIE = 11
 
 stars_max = 40
 log2_index_max = 65
@@ -124,6 +125,8 @@ def Table(bpf, map_id, map_fd, keytype, leaftype, **kwargs):
         t = PerCpuHash(bpf, map_id, map_fd, keytype, leaftype, **kwargs)
     elif ttype == BPF_MAP_TYPE_PERCPU_ARRAY:
         t = PerCpuArray(bpf, map_id, map_fd, keytype, leaftype, **kwargs)
+    elif ttype == BPF_MAP_TYPE_LPM_TRIE:
+        t = LpmTrie(bpf, map_id, map_fd, keytype, leaftype)
     elif ttype == BPF_MAP_TYPE_STACK_TRACE:
         t = StackTrace(bpf, map_id, map_fd, keytype, leaftype)
     elif ttype == BPF_MAP_TYPE_LRU_HASH:
@@ -665,6 +668,18 @@ class PerCpuArray(ArrayBase):
         result = self.sum(key)
         return result.value / self.total_cpu
 
+class LpmTrie(TableBase):
+    def __init__(self, *args, **kwargs):
+        super(LpmTrie, self).__init__(*args, **kwargs)
+
+    def __len__(self):
+        raise NotImplementedError
+
+    def __delitem__(self, key):
+        # Not implemented for lpm trie as of kernel commit
+        # b95a5c4db09bc7c253636cb84dc9b12c577fd5a0
+        raise NotImplementedError
+
 class StackTrace(TableBase):
     MAX_DEPTH = 127
 

tests/python/test_lpm_trie.py

+#!/usr/bin/env python
+# Copyright (c) 2017 Facebook, Inc.
+# Licensed under the Apache License, Version 2.0 (the "License")
+
+import ctypes as ct
+import unittest
+from bcc import BPF
+from netaddr import IPAddress
+
+class KeyV4(ct.Structure):
+    _fields_ = [("prefixlen", ct.c_uint),
+                ("data", ct.c_ubyte * 4)]
+
+class KeyV6(ct.Structure):
+    _fields_ = [("prefixlen", ct.c_uint),
+                ("data", ct.c_ushort * 8)]
+
+class TestLpmTrie(unittest.TestCase):
+    def test_lpm_trie_v4(self):
+        test_prog1 = """
+        BPF_F_TABLE("lpm_trie", u64, int, trie, 16, BPF_F_NO_PREALLOC);
+        """
+        b = BPF(text=test_prog1)
+        t = b["trie"]
+
+        k1 = KeyV4(24, (192, 168, 0, 0))
+        v1 = ct.c_int(24)
+        t[k1] = v1
+
+        k2 = KeyV4(28, (192, 168, 0, 0))
+        v2 = ct.c_int(28)
+        t[k2] = v2
+
+        k = KeyV4(32, (192, 168, 0, 15))
+        self.assertEqual(t[k].value, 28)
+
+        k = KeyV4(32, (192, 168, 0, 127))
+        self.assertEqual(t[k].value, 24)
+
+        with self.assertRaises(KeyError):
+            k = KeyV4(32, (172, 16, 1, 127))
+            v = t[k]
+
+    def test_lpm_trie_v6(self):
+        test_prog1 = """
+        struct key_v6 {
+            u32 prefixlen;
+            u32 data[4];
+        };
+        BPF_F_TABLE("lpm_trie", struct key_v6, int, trie, 16, BPF_F_NO_PREALLOC);
+        """
+        b = BPF(text=test_prog1)
+        t = b["trie"]
+
+        k1 = KeyV6(64, IPAddress('2a00:1450:4001:814:200e::').words)
+        v1 = ct.c_int(64)
+        t[k1] = v1
+
+        k2 = KeyV6(96, IPAddress('2a00:1450:4001:814::200e').words)
+        v2 = ct.c_int(96)
+        t[k2] = v2
+
+        k = KeyV6(128, IPAddress('2a00:1450:4001:814::1024').words)
+        self.assertEqual(t[k].value, 96)
+
+        k = KeyV6(128, IPAddress('2a00:1450:4001:814:2046::').words)
+        self.assertEqual(t[k].value, 64)
+
+        with self.assertRaises(KeyError):
+            k = KeyV6(128, IPAddress('2a00:ffff::').words)
+            v = t[k]
+
+if __name__ == "__main__":
+    unittest.main()