commit f31a45416ca1bdb9576e4167f591ad134f8aa4ce
author Maciej Żenczykowski <maze@google.com> Thu Feb 06 12:51:17 2025 -0800
committer Maciej Żenczykowski <maze@google.com> Thu Feb 06 12:56:09 2025 -0800
tree 5aeece14b1bd74582a02513cf157a22f3b97452d
parent 7805afe4184ca4bc1d0976149168aedad171b8c0

TcUtils: allow ignoring netlink error code ENOENT

Ignore this error code during DEL operations.

It is returned when the specific thing to be deleted
is not found and is therefore a valid response.

Gets rid of 30+ logs worth of:
  E TcUtils : NLMSG_ERROR message return error: -2
during netd startup (cleanup phase).

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ie542f8ff418dbed604eea5b31b87f9b974ccdbcb

staticlibs/native/tcutils/tcutils.cpp

diff --git a/staticlibs/native/tcutils/tcutils.cpp b/staticlibs/native/tcutils/tcutils.cpp
index 21e781c..5425d0e 100644
--- a/staticlibs/native/tcutils/tcutils.cpp
+++ b/staticlibs/native/tcutils/tcutils.cpp
@@ -361,7 +361,7 @@
 const sockaddr_nl KERNEL_NLADDR = {AF_NETLINK, 0, 0, 0};
 const uint16_t NETLINK_REQUEST_FLAGS = NLM_F_REQUEST | NLM_F_ACK;
 
-int sendAndProcessNetlinkResponse(const void *req, int len) {
+int sendAndProcessNetlinkResponse(const void *req, int len, bool enoent_ok) {
   // TODO: use unique_fd instead of ScopeGuard
   unique_fd fd(socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE));
   if (!fd.ok()) {
@@ -445,7 +445,9 @@
     return -ENOMSG;
   }
 
-  if (resp.e.error) {
+  if (resp.e.error == -ENOENT) {
+    if (!enoent_ok) ALOGE("NLMSG_ERROR message returned ENOENT");
+  } else if (resp.e.error) {
     ALOGE("NLMSG_ERROR message return error: %d", resp.e.error);
   }
   return resp.e.error; // returns 0 on success
@@ -560,7 +562,8 @@
   };
 #undef CLSACT
 
-  return sendAndProcessNetlinkResponse(&req, sizeof(req));
+  const bool enoent_ok = (nlMsgType == RTM_DELQDISC);
+  return sendAndProcessNetlinkResponse(&req, sizeof(req), enoent_ok);
 }
 
 // tc filter add dev .. in/egress prio 1 protocol ipv6/ip bpf object-pinned
@@ -666,7 +669,7 @@
   snprintf(req.options.name.str, sizeof(req.options.name.str), "%s:[*fsobj]",
            basename(bpfProgPath));
 
-  int error = sendAndProcessNetlinkResponse(&req, sizeof(req));
+  int error = sendAndProcessNetlinkResponse(&req, sizeof(req), false);
   return error;
 }
 
@@ -698,7 +701,8 @@
     return error;
   }
   return sendAndProcessNetlinkResponse(filter.getRequest(),
-                                       filter.getRequestSize());
+                                       filter.getRequestSize(),
+                                       false);
 }
 
 // tc filter del dev .. in/egress prio .. protocol ..
@@ -726,7 +730,7 @@
           },
   };
 
-  return sendAndProcessNetlinkResponse(&req, sizeof(req));
+  return sendAndProcessNetlinkResponse(&req, sizeof(req), true);
 }
 
 } // namespace android