Add two new map types: DEVMAP and CPUMAP

Those two map types are necessary to support bpf_redirect_map() in XDP.

v2:
  Use ArrayBase as the base class of DevMap and CpuMap
Signed-off-by: Gary Lin <glin@suse.com>

src/cc/export/helpers.h

@@ -201,6 +201,23 @@ struct bpf_stacktrace {
 #define BPF_PROG_ARRAY(_name, _max_entries) \
   BPF_TABLE("prog", u32, u32, _name, _max_entries)
 
+#define BPF_XDP_REDIRECT_MAP(_table_type, _leaf_type, _name, _max_entries) \
+struct _name##_table_t { \
+  u32 key; \
+  _leaf_type leaf; \
+  /* xdp_act = map.redirect_map(index, flag) */ \
+  u64 (*redirect_map) (int, int); \
+  u32 max_entries; \
+}; \
+__attribute__((section("maps/"_table_type))) \
+struct _name##_table_t _name = { .max_entries = (_max_entries) }
+
+#define BPF_DEVMAP(_name, _max_entries) \
+  BPF_XDP_REDIRECT_MAP("devmap", int, _name, _max_entries)
+
+#define BPF_CPUMAP(_name, _max_entries) \
+  BPF_XDP_REDIRECT_MAP("cpumap", u32, _name, _max_entries)
+
 // packet parsing state machine helpers
 #define cursor_advance(_cursor, _len) \
   ({ void *_tmp = _cursor; _cursor += _len; _tmp; })

src/cc/frontends/clang/b_frontend_action.cc

@@ -609,6 +609,9 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
           } else if (memb_name == "check_current_task") {
             prefix = "bpf_current_task_under_cgroup";
             suffix = ")";
+          } else if (memb_name == "redirect_map") {
+            prefix = "bpf_redirect_map";
+            suffix = ")";
           } else {
             error(Call->getLocStart(), "invalid bpf_table operation %0") << memb_name;
             return false;
@@ -920,6 +923,10 @@ bool BTypeVisitor::VisitVarDecl(VarDecl *Decl) {
       map_type = BPF_MAP_TYPE_CGROUP_ARRAY;
     } else if (A->getName() == "maps/stacktrace") {
       map_type = BPF_MAP_TYPE_STACK_TRACE;
+    } else if (A->getName() == "maps/devmap") {
+      map_type = BPF_MAP_TYPE_DEVMAP;
+    } else if (A->getName() == "maps/cpumap") {
+      map_type = BPF_MAP_TYPE_CPUMAP;
     } else if (A->getName() == "maps/extern") {
       if (!fe_.table_storage().Find(global_path, table_it)) {
         error(Decl->getLocStart(), "reference to undefined table");

src/python/bcc/table.py

@@ -36,6 +36,13 @@ 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
+BPF_MAP_TYPE_ARRAY_OF_MAPS = 12
+BPF_MAP_TYPE_HASH_OF_MAPS = 13
+BPF_MAP_TYPE_DEVMAP = 14
+BPF_MAP_TYPE_SOCKMAP = 15
+BPF_MAP_TYPE_CPUMAP = 16
+BPF_MAP_TYPE_XSKMAP = 17
+BPF_MAP_TYPE_SOCKHASH = 18
 
 stars_max = 40
 log2_index_max = 65
@@ -144,6 +151,10 @@ def Table(bpf, map_id, map_fd, keytype, leaftype, **kwargs):
         t = LruPerCpuHash(bpf, map_id, map_fd, keytype, leaftype)
     elif ttype == BPF_MAP_TYPE_CGROUP_ARRAY:
         t = CgroupArray(bpf, map_id, map_fd, keytype, leaftype)
+    elif ttype == BPF_MAP_TYPE_DEVMAP:
+        t = DevMap(bpf, map_id, map_fd, keytype, leaftype)
+    elif ttype == BPF_MAP_TYPE_CPUMAP:
+        t = CpuMap(bpf, map_id, map_fd, keytype, leaftype)
     if t == None:
         raise Exception("Unknown table type %d" % ttype)
     return t
@@ -766,3 +777,11 @@ class StackTrace(TableBase):
 
     def clear(self):
         pass
+
+class DevMap(ArrayBase):
+    def __init__(self, *args, **kwargs):
+        super(DevMap, self).__init__(*args, **kwargs)
+
+class CpuMap(ArrayBase):
+    def __init__(self, *args, **kwargs):
+        super(CpuMap, self).__init__(*args, **kwargs)