tools/syz-declextract: add entry function and access level

For now for netlink only.

2 files changed, 56 insertions, 11 deletions

diff --git a/tools/syz-declextract/run.go b/tools/syz-declextract/run.go
index 5794c2a45..2feddfec8 100644
--- a/tools/syz-declextract/run.go
+++ b/tools/syz-declextract/run.go
@@ -144,7 +144,9 @@ type Interface struct {
 	Type               string   `json:"type"`
 	Name               string   `json:"name"`
 	Files              []string `json:"files"`
-	Subsystems         []string `json:"subsystems"`
+	Func               string   `json:"func,omitempty"`
+	Access             string   `json:"access,omitempty"`
+	Subsystems         []string `json:"subsystems,omitempty"`
 	ManualDescriptions bool     `json:"has_manual_descriptions"`
 	AutoDescriptions   bool     `json:"has_auto_descriptions"`
 
@@ -415,11 +417,21 @@ func appendNodes(slice *[]ast.Node, interfaces map[string]Interface, nodes []ast
 				continue
 			}
 			fields := strings.Fields(node.Text)
+			if len(fields) != 6 {
+				tool.Failf("%q has wrong number of fields", node.Text)
+			}
+			for i := range fields {
+				if fields[i] == "-" {
+					fields[i] = ""
+				}
+			}
 			iface := Interface{
 				Type:             fields[1],
 				Name:             fields[2],
 				Files:            []string{file},
 				identifyingConst: fields[3],
+				Func:             fields[4],
+				Access:           fields[5],
 			}
 			if iface.Type == "SYSCALL" {
 				for _, name := range syscallNames[iface.Name] {
diff --git a/tools/syz-declextract/syz-declextract.cpp b/tools/syz-declextract/syz-declextract.cpp
index 0a24c6418..392875c3d 100644
--- a/tools/syz-declextract/syz-declextract.cpp
+++ b/tools/syz-declextract/syz-declextract.cpp
@@ -43,6 +43,11 @@
 using namespace clang;
 using namespace clang::ast_matchers;
 
+const char *const AccessUnknown = "-";
+const char *const AccessUser = "user";
+const char *const AccessNsAdmin = "ns_admin";
+const char *const AccessAdmin = "admin";
+
 struct Param {
   std::string type;
   std::string name;
@@ -50,6 +55,8 @@ struct Param {
 
 struct NetlinkOps {
   std::string cmd;
+  std::string func;
+  const char *access;
   std::optional<std::string> policy;
 };
 
@@ -64,8 +71,12 @@ struct StructMember {
   unsigned int countedBy;
 };
 
-void emitInterface(const char *type, std::string_view name, std::string_view identifying_const) {
-  printf("\n#INTERFACE: %s %s %s\n\n", type, std::string(name).c_str(), std::string(identifying_const).c_str());
+void emitInterface(const char *type, std::string_view name, std::string_view identifying_const,
+                   std::string_view entry_func = "", const char *access = AccessUnknown) {
+  if (entry_func.empty())
+    entry_func = "-";
+  printf("\n#INTERFACE: %s %s %s %s %s\n\n", type, std::string(name).c_str(), std::string(identifying_const).c_str(),
+         std::string(entry_func).c_str(), access);
 }
 
 struct SyzRecordDecl {
@@ -96,6 +107,14 @@ struct SyzRecordDecl {
   }
 };
 
+// If expression refers to some identifier, returns the identifier name.
+// Otherwise returns an empty string.
+// For example, if the expression is `function_name`, returns "function_name" string.
+std::string getDeclName(const clang::Expr *expr) {
+  auto *decl = llvm::dyn_cast<DeclRefExpr>(expr->IgnoreCasts());
+  return decl ? decl->getDecl()->getNameAsString() : "";
+}
+
 bool endsWith(const std::string_view &str, const std::string_view end) {
   size_t substrBegin = str.rfind(end);
   return substrBegin != std::string::npos && str.substr(substrBegin) == end;
@@ -758,7 +777,6 @@ private:
   }
 
   std::map<std::string, unsigned> genlFamilyMember;
-  std::map<std::string, std::map<std::string, unsigned>> opsMember;
 
   std::optional<std::string> getPolicyName(const MatchFinder::MatchResult &Result, const ValueDecl *decl) {
     if (!decl) {
@@ -775,10 +793,9 @@ private:
     // when multiple policies are named the same but have different definitions
   }
 
-  std::vector<NetlinkOps> getOps(const MatchFinder::MatchResult &Result, const std::string opsName,
+  std::vector<NetlinkOps> getOps(const MatchFinder::MatchResult &Result, const std::string &opsName,
                                  const InitListExpr *init) {
     ASTContext *context = Result.Context;
-    std::vector<NetlinkOps> ops;
     const auto n_ops = init->getInit(genlFamilyMember["n_" + opsName])->getIntegerConstantExpr(*context);
     const auto &opsRef = init->getInit(genlFamilyMember[opsName])->getAsBuiltinConstantDeclRef(*context);
     if (!n_ops || !opsRef) {
@@ -791,21 +808,37 @@ private:
       return {};
     }
     const auto *opsInit = llvm::dyn_cast<InitListExpr>(opsDecl->getInit());
+    std::map<std::string, unsigned> opsMember;
     for (const auto &field : opsInit->getInit(0)->getType()->getAsRecordDecl()->fields()) {
-      opsMember[opsName][field->getNameAsString()] = field->getFieldIndex();
+      opsMember[field->getNameAsString()] = field->getFieldIndex();
     }
+    std::vector<NetlinkOps> ops;
     for (int i = 0; i < n_ops; ++i) {
       const auto &init = llvm::dyn_cast<InitListExpr>(opsInit->getInit(i));
-      const auto &cmdInit = init->getInit(opsMember[opsName]["cmd"])->getEnumConstantDecl();
+      const auto &cmdInit = init->getInit(opsMember["cmd"])->getEnumConstantDecl();
       if (!cmdInit) {
         continue;
       }
       const auto &cmd = cmdInit->getNameAsString();
       const ValueDecl *policyDecl = nullptr;
       if (opsName != "small_ops") {
-        policyDecl = init->getInit(opsMember[opsName]["policy"])->getAsBuiltinConstantDeclRef(*context);
+        policyDecl = init->getInit(opsMember["policy"])->getAsBuiltinConstantDeclRef(*context);
       }
-      ops.push_back({std::move(cmd), getPolicyName(Result, policyDecl)});
+      std::string func = getDeclName(init->getInit(opsMember["doit"]));
+      if (func.empty())
+        func = getDeclName(init->getInit(opsMember["dumpit"]));
+      const Expr *flagsDecl = init->getInit(opsMember["flags"]);
+      Expr::EvalResult flags;
+      flagsDecl->EvaluateAsConstantExpr(flags, *context);
+      auto flagsVal = flags.Val.getInt().getExtValue();
+      const char *access = AccessUser;
+      constexpr int GENL_ADMIN_PERM = 0x01;
+      constexpr int GENL_UNS_ADMIN_PERM = 0x10;
+      if (flagsVal & GENL_ADMIN_PERM)
+        access = AccessAdmin;
+      else if (flagsVal & GENL_UNS_ADMIN_PERM)
+        access = AccessNsAdmin;
+      ops.push_back({std::move(cmd), func, access, getPolicyName(Result, policyDecl)});
     }
     return ops;
   }
@@ -847,7 +880,7 @@ private:
         } else {
           continue;
         }
-        emitInterface("NETLINK", ops.cmd, ops.cmd);
+        emitInterface("NETLINK", ops.cmd, ops.cmd, ops.func, ops.access);
         printf("sendmsg$auto_%s(fd sock_nl_generic, msg ptr[in, %s[%s, %s]], f flags[send_flags]) (automatic)\n",
                ops.cmd.c_str(), msghdr.c_str(), ops.cmd.c_str(), policyName);
         printedCmds = true;