From f3fabb47252fb2f31622e464f30ce10823b804c4 Mon Sep 17 00:00:00 2001
From: dengxuyue <dengxuyue@huawei.com>
Date: Sat, 17 Apr 2021 15:09:55 +0800
Subject: [PATCH] Fix communiction issues

---
 src/common/backend/libpq/pqcomm.cpp       | 67 +++++++++++++++++++++++
 src/gausskernel/process/tcop/postgres.cpp |  1 +
 src/include/libpq/libpq.h                 |  1 +
 3 files changed, 69 insertions(+)

diff --git a/src/common/backend/libpq/pqcomm.cpp b/src/common/backend/libpq/pqcomm.cpp
index 1a9cb5b6e..6fd03a32a 100644
--- a/src/common/backend/libpq/pqcomm.cpp
+++ b/src/common/backend/libpq/pqcomm.cpp
@@ -1317,6 +1317,21 @@ static int pq_discardbytes(size_t len)
 {
     size_t amount;
 
+    ereport(WARNING,
+        (errcode(ERRCODE_PROTOCOL_VIOLATION),
+            errmsg("incomplete message, client info [Remote IP: %s PORT: %s FD: %d BLOCK: %d], "
+                "packet info [PqRecvLength: %d PqRecvPointer: %d expectedLen: %d].",
+                u_sess->proc_cxt.MyProcPort->remote_host,
+                (u_sess->proc_cxt.MyProcPort->remote_port != NULL &&
+                 u_sess->proc_cxt.MyProcPort->remote_port[0] != '\0')
+                ? u_sess->proc_cxt.MyProcPort->remote_port : "",
+                u_sess->proc_cxt.MyProcPort->sock,
+                u_sess->proc_cxt.MyProcPort->noblock,
+                t_thrd.libpq_cxt.PqRecvLength,
+                t_thrd.libpq_cxt.PqRecvPointer,
+                (int)len)));
+    PrintUnexpectedBufferContent(t_thrd.libpq_cxt.PqRecvBuffer, t_thrd.libpq_cxt.PqRecvLength);
+
     while (len > 0) {
         while (t_thrd.libpq_cxt.PqRecvPointer >= t_thrd.libpq_cxt.PqRecvLength) {
             if (pq_recvbuf()) { /* If nothing in buffer, then recv some */
@@ -2407,3 +2422,55 @@ static size_t pq_disk_read_data_block(
 
     return read_len;
 }
+
+/*
+ * To facilitate fault locating, abnormal packets need to be recorded.
+ * For security purposes, the maximum print length does not exceed the buffer length.
+ */
+void PrintUnexpectedBufferContent(const char *buffer, int len)
+{
+    if (buffer == NULL) {
+        Assert(buffer);
+        ereport(ERROR,
+            (errmodule(MOD_COMM_PARAM),
+                errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+                errmsg("PrintUnexpectedPqBufferContent: invalid params[buffer: null len: %d]", len)));
+    }
+    if (len <= 0) {
+        return;
+    }
+
+    /* Line-by-line printing with a width limit of 1024 */
+    const int nBytePrintLine = 1024;
+    const int pqBufferSize = PQ_BUFFER_SIZE;
+    const char defaultNullChar = ' ';
+    char tmp[nBytePrintLine + 1] = {0};
+    int i, idx = 0;
+    len = (len > pqBufferSize) ? pqBufferSize : len;
+
+    ereport(WARNING, (errmsg("--------buffer begin--------")));
+    for (i = 0; i < len; i++) {
+        idx = i % nBytePrintLine;
+
+        if (buffer[i] != '\0') {
+            tmp[idx] = buffer[i];
+        } else {
+            tmp[idx] = defaultNullChar;
+        }
+        if ((i + 1) % nBytePrintLine == 0) {
+            ereport(WARNING, (errmsg("%s", tmp)));
+        }
+    }
+
+    /* Output buffer with the remaining length. */
+    if (len % nBytePrintLine != 0) {
+        /* reset dirty data */
+        if (idx <= nBytePrintLine) {
+            errno_t rc = memset_s(tmp + idx + 1, nBytePrintLine - idx, 0, nBytePrintLine - idx);
+            securec_check(rc, "\0", "\0");
+        }
+        ereport(WARNING, (errmsg("%s", tmp)));
+    }
+    ereport(WARNING, (errmsg("--------buffer end--------")));
+    return;
+}
diff --git a/src/gausskernel/process/tcop/postgres.cpp b/src/gausskernel/process/tcop/postgres.cpp
index e0854e147..0ff87e897 100644
--- a/src/gausskernel/process/tcop/postgres.cpp
+++ b/src/gausskernel/process/tcop/postgres.cpp
@@ -7937,6 +7937,7 @@ int PostgresMain(int argc, char* argv[], const char* dbname, const char* usernam
                 pgstatCountSQL4SessionLevel();
 
                 if (strlen(query_string) + 1 > sizeof(sql)) {
+                    PrintUnexpectedBufferContent(query_string, sizeof(sql));
                     ereport(ERROR,
                         (errcode(ERRCODE_SYSTEM_ERROR),
                             errmsg("Acceptter in pooler stateless resue mode reset connection params %d > sql[%d].",
diff --git a/src/include/libpq/libpq.h b/src/include/libpq/libpq.h
index 76a409c83..c48d0a243 100644
--- a/src/include/libpq/libpq.h
+++ b/src/include/libpq/libpq.h
@@ -82,6 +82,7 @@ extern int secure_open_server(Port* port);
 extern void secure_close(Port* port);
 extern ssize_t secure_read(Port* port, void* ptr, size_t len);
 extern ssize_t secure_write(Port* port, void* ptr, size_t len);
+extern void PrintUnexpectedBufferContent(const char *buffer, int len);
 
 /*
  * interface for flushing sendbuffer to disk