tools: filter/display using PID intead of TID

Signed-off-by: Hengqi Chen <chenhengqi@outlook.com>
diff --git a/tools/sslsniff.py b/tools/sslsniff.py
index 0200750..02b7360 100755
--- a/tools/sslsniff.py
+++ b/tools/sslsniff.py
@@ -66,7 +66,9 @@
 BPF_PERF_OUTPUT(perf_SSL_write);
 
 int probe_SSL_write(struct pt_regs *ctx, void *ssl, void *buf, int num) {
-        u32 pid = bpf_get_current_pid_tgid();
+        u64 pid_tgid = bpf_get_current_pid_tgid();
+        u32 pid = pid_tgid >> 32;
+
         FILTER
 
         struct probe_SSL_data_t __data = {0};
@@ -89,18 +91,24 @@
 BPF_HASH(bufs, u32, u64);
 
 int probe_SSL_read_enter(struct pt_regs *ctx, void *ssl, void *buf, int num) {
-        u32 pid = bpf_get_current_pid_tgid();
+        u64 pid_tgid = bpf_get_current_pid_tgid();
+        u32 pid = pid_tgid >> 32;
+        u32 tid = (u32)pid_tgid;
+
         FILTER
 
-        bufs.update(&pid, (u64*)&buf);
+        bufs.update(&tid, (u64*)&buf);
         return 0;
 }
 
 int probe_SSL_read_exit(struct pt_regs *ctx, void *ssl, void *buf, int num) {
-        u32 pid = bpf_get_current_pid_tgid();
+        u64 pid_tgid = bpf_get_current_pid_tgid();
+        u32 pid = pid_tgid >> 32;
+        u32 tid = (u32)pid_tgid;
+
         FILTER
 
-        u64 *bufp = bufs.lookup(&pid);
+        u64 *bufp = bufs.lookup(&tid);
         if (bufp == 0) {
                 return 0;
         }
@@ -116,7 +124,7 @@
                 bpf_probe_read_user(&__data.v0, sizeof(__data.v0), (char *)*bufp);
         }
 
-        bufs.delete(&pid);
+        bufs.delete(&tid);
 
         perf_SSL_read.perf_submit(ctx, &__data, sizeof(__data));
         return 0;
@@ -176,7 +184,7 @@
 
 
 # header
-print("%-12s %-18s %-16s %-6s %-6s" % ("FUNC", "TIME(s)", "COMM", "PID",
+print("%-12s %-18s %-16s %-7s %-6s" % ("FUNC", "TIME(s)", "COMM", "PID",
                                        "LEN"))
 
 # process event
@@ -213,7 +221,7 @@
         e_mark = "-" * 5 + " END DATA (TRUNCATED, " + str(truncated_bytes) + \
                 " bytes lost) " + "-" * 5
 
-    fmt = "%-12s %-18.9f %-16s %-6d %-6d\n%s\n%s\n%s\n\n"
+    fmt = "%-12s %-18.9f %-16s %-7d %-6d\n%s\n%s\n%s\n\n"
     if args.hexdump:
         unwrapped_data = binascii.hexlify(event.v0)
         data = textwrap.fill(unwrapped_data.decode('utf-8', 'replace'),width=32)