From d1ec0541a88cd44822685c7d2c9381d591b3565c Mon Sep 17 00:00:00 2001
From: Bin Tang <tangbin.bin@bytedance.com>
Date: Thu, 24 Aug 2023 14:45:28 +0800
Subject: [PATCH] optimizer: transmit container id to optimizer via map

Signed-off-by: Bin Tang <tangbin.bin@bytedance.com>
---
 pkg/optimizer/ebpf/conn/conn.go | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/pkg/optimizer/ebpf/conn/conn.go b/pkg/optimizer/ebpf/conn/conn.go
index bb25916331..dd376fa009 100644
--- a/pkg/optimizer/ebpf/conn/conn.go
+++ b/pkg/optimizer/ebpf/conn/conn.go
@@ -9,7 +9,6 @@ package conn
 import (
 	"bytes"
 	"encoding/binary"
-	"strings"
 	"time"
 
 	bpf "github.com/iovisor/gobpf/bcc"
@@ -18,7 +17,7 @@ import (
 
 import "C"
 
-const templateSource string = `
+const sourceCode string = `
 #include <net/sock.h>
 #include <linux/mount.h>
 #include <linux/mm.h>
@@ -42,6 +41,9 @@ struct buf_s {
     char buf[FILE_PATH_LEN*2];
 };
 
+char container_id[CONTAINER_ID_LEN];
+
+BPF_ARRAY(id_buf, container_id, 1);
 BPF_PERCPU_ARRAY(path_buf, struct buf_s, 1);
 BPF_PERCPU_ARRAY(event_buf, struct request_info, 1);
 BPF_HASH(vfs_read_start_trace, u64, struct request_info);
@@ -57,8 +59,13 @@ static int container_id_filter() {
     struct task_struct *curr_task;
     struct kernfs_node *knode, *pknode;
     char container_id[CONTAINER_ID_LEN];
-    char expected_container_id[CONTAINER_ID_LEN] = "EXCEPTED_CONTAINERD_ID";
     char end = 0;
+    int zero = 0;
+    char *buf_id = container_id.lookup(&zero);
+    if (!buf_id) {
+        return -1;
+    }
+
     curr_task = (struct task_struct *) bpf_get_current_task();
 
     knode = curr_task->cgroups->subsys[0]->cgroup->kn;
@@ -68,7 +75,7 @@ static int container_id_filter() {
     else
         bpf_probe_read(container_id, 1, &end);
 
-    return local_strcmp(container_id, expected_container_id);
+    return local_strcmp(container_id, buf_id);
 }
 
 static void fill_file_path(struct file *file, char *file_path) {
@@ -277,9 +284,7 @@ func kprobeSyscall(m *bpf.Module, syscall string, kprobeEntry string) error {
 }
 
 func InitKprobeTable(id string) (*bpf.Module, *bpf.Table, error) {
-	source := strings.ReplaceAll(templateSource, "EXCEPTED_CONTAINERD_ID", id)
-
-	m := bpf.NewModule(source, []string{})
+	m := bpf.NewModule(sourceCode, []string{})
 
 	if err := kprobeSyscall(m, "vfs_read", "trace_vfs_read_entry"); err != nil {
 		return nil, nil, err
@@ -300,6 +305,11 @@ func InitKprobeTable(id string) (*bpf.Module, *bpf.Table, error) {
 		return nil, nil, err
 	}
 
+	byteID := make([]byte, 1)
+	binary.LittleEndian.PutUint32(byteID, 0)
+	containerIdTable := bpf.NewTable(m.TableId("id_buf"), m)
+	containerIdTable.Set(byteID, []byte(id))
+
 	table := bpf.NewTable(m.TableId("fille_access_events"), m)
 
 	return m, table, nil