Fix for CONC-70: Unknown error when reading large packets via conpressed protocol

libmariadb/my_compress.c

@@ -83,6 +83,7 @@ my_bool my_uncompress (unsigned char *packet, size_t *len, size_t *complen)
     memcpy(packet,compbuf,*len);
     my_free((gptr)compbuf,MYF(MY_WME));
   }
+  else *complen= *len;
   return 0;
 }
 #endif /* HAVE_COMPRESS */

libmariadb/net.c

@@ -37,7 +37,7 @@
 
 #define MAX_PACKET_LENGTH (256L*256L*256L-1)
 
-/* net_buffer_length and max_allowec_packet are defined in mysql.h
+/* net_buffer_length and max_allowed_packet are defined in mysql.h
    See bug conc-57
 */
 #undef net_buffer_length
@@ -713,54 +713,120 @@ ulong my_net_read(NET *net)
   }
   else
   {
-    if (net->remain_in_buf)
+    /* 
+    compressed protocol:
+
+    --------------------------------------
+    packet_lengt h      3 
+    sequence_id         1
+    uncompressed_length 3
+    --------------------------------------
+    compressed data     packet_length - 7
+    --------------------------------------
+
+    Another packet will follow if:
+    packet_length == MAX_PACKET_LENGTH
+
+    Last package will be identified by
+    - packet_length is zero (special case)
+    - packet_length < MAX_PACKET_LENGTH
+    */
+
+    size_t packet_length,
+           buffer_length;
+    size_t current= 0, start= 0;
+    my_bool is_multi_packet= 0;
+
+    /* check if buffer is empty */
+    if (!net->remain_in_buf)
     {
-      /* restore 0 character */
+      buffer_length= 0;
+    }
+    else
+    {
+      /* save position and restore \0 character */
+      buffer_length= net->buf_length;
+      current= net->buf_length - net->remain_in_buf;
+      start= current;
       net->buff[net->buf_length - net->remain_in_buf]=net->save_char;
     }
     for (;;)
     {
-      if (net->remain_in_buf)
+      if (buffer_length - current >= 4)
       {
-        uchar *pos = net->buff + net->buf_length - net->remain_in_buf;
+        uchar *pos= net->buff + current;
-        if (net->remain_in_buf >= 4)
+        packet_length= uint3korr(pos);
+
+        /* check if we have last package (special case: zero length) */
+        if (!packet_length)
         {
-          net->length = uint3korr(pos);
+          current+= 4; /* length + sequence_id,
-          if (net->length <= net->remain_in_buf - 4)
+                          no more data will follow */
+          break;
+        }
+        if (packet_length + 4 <= buffer_length - current)
+        {
+          if (!is_multi_packet)
           {
-            /* We have a full packet */
+            current= current + packet_length + 4;
-            len=net->length;
-            net->remain_in_buf -= net->length + 4;
-            net->read_pos=pos + 4;
-            break;			/* We have a full packet */
           }
+          else
+          {
+            /* remove packet_header */
+            memmove(net->buff + current, 
+                     net->buff + current + 4, 
+                     buffer_length - current);
+            buffer_length-= 4;
+            current+= packet_length;
+          }
+          /* do we have last packet ? */
+          if (packet_length != MAX_PACKET_LENGTH)
+          {
+            is_multi_packet= 0;
+            break;
+          }
+          else
+            is_multi_packet= 1;
+          if (start)
+          {
+            memmove(net->buff, net->buff + start,
+                    buffer_length - start);
+            /* decrease buflen*/
+            buffer_length-= start;
+            start= 0;
+          }
+          continue;
         }
-        /* Move data down to read next data packet after current one */
-        if (net->buf_length != net->remain_in_buf)
-        {
-          memmove(net->buff,pos,net->remain_in_buf);
-          net->buf_length=net->remain_in_buf;
-        }
-        net->where_b=net->buf_length;
       }
-      else
+      if (start)
-      {
+      { 
-        net->where_b=0;
+        memmove(net->buff, net->buff + start, buffer_length - start);
-        net->buf_length=0;
+        /* decrease buflen and current */
+        current -= start;
+        buffer_length-= start;
+        start= 0;
       }
 
-      if ((len = my_real_read(net,(size_t *)&complen)) == packet_error)
+      net->where_b=buffer_length;
+
+      if ((packet_length = my_real_read(net,(size_t *)&complen)) == packet_error)
         break;
-      if (my_uncompress((unsigned char*) net->buff + net->where_b, &len, &complen))
+      if (my_uncompress((unsigned char*) net->buff + net->where_b, &packet_length, &complen))
       {
         len= packet_error;
         net->error=2;			/* caller will close socket */
         net->last_errno=ER_NET_UNCOMPRESS_ERROR;
         break;
       }
-      net->buf_length+=(unsigned long)len;
+      buffer_length+= complen;
-      net->remain_in_buf+=(unsigned long)len;
     }
+    /* set values */
+    net->buf_length= buffer_length;
+    net->remain_in_buf= buffer_length - current;
+    net->read_pos= net->buff + start + 4;
+    len= current - start - 4;
+    if (is_multi_packet)
+      len-= 4;
     if (len != packet_error)
     {
       net->save_char= net->read_pos[len];	/* Must be saved */

unittest/libmariadb/basic-t.c

@@ -30,11 +30,21 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "my_test.h"
 #include "ma_common.h"
 
-static int test_conc68(MYSQL *mysql)
+static int test_conc70(MYSQL *my)
 {
   int rc;
   MYSQL_RES *res;
   MYSQL_ROW row;
+  MYSQL *mysql= mysql_init(NULL);
+
+  mysql_query(my, "SET @a:=@@max_allowed_packet");
+  check_mysql_rc(rc, my);
+
+  mysql_query(my, "SET global max_allowed_packet=1024*1024*22");
+
+  mysql_options(mysql, MYSQL_OPT_COMPRESS, (void *)1);
+  FAIL_IF(!mysql_real_connect(mysql, hostname, username, password, schema,
+                         port, socketname, 0), mysql_error(my));
 
   rc= mysql_query(mysql, "DROP TABLE IF EXISTS t1");
   check_mysql_rc(rc, mysql);
@@ -43,7 +53,7 @@ static int test_conc68(MYSQL *mysql)
   check_mysql_rc(rc, mysql);
 
   rc= mysql_query(mysql, "INSERT INTO t1 VALUES (REPEAT('A', 1024 * 1024 * 20))");
-  check_mysql_rc(rc, mysql);
+  check_mysql_rc(rc, mysql); 
 
   rc= mysql_query(mysql, "SELECT a FROM t1");
   check_mysql_rc(rc, mysql);
@@ -55,47 +65,65 @@ static int test_conc68(MYSQL *mysql)
   }
 
   row= mysql_fetch_row(res);
+  diag("Length: %ld", strlen(row[0]));
   FAIL_IF(strlen(row[0]) != 1024 * 1024 * 20, "Wrong length");
+
   mysql_free_result(res);
+  mysql_close(mysql);
+
+  rc= mysql_query(my, "SET global max_allowed_packet=@a");
+  check_mysql_rc(rc, my);
 
   return OK;
 }
 
-static int test_conc66(MYSQL *my)
+static int test_conc68(MYSQL *my)
 {
-  MYSQL *mysql= mysql_init(NULL);
   int rc;
-  FILE *fp;
+  MYSQL_RES *res;
+  MYSQL_ROW row;
+  MYSQL *mysql= mysql_init(NULL);
 
-  fp= fopen("./my.cnf", "w");
+  mysql_query(my, "SET @a:=@@max_allowed_packet");
-  fprintf(fp, "[conc-66]\nuser=conc-66\npassword=\"my#pass;word\"");
+  check_mysql_rc(rc, my);
-  fclose(fp);
 
-  rc= mysql_query(my, "GRANT ALL ON test.* to 'conc-66'@'%' identified by 'my#pass;word'");
+  mysql_query(my, "SET global max_allowed_packet=1024*1024*22");
-  check_mysql_rc(rc, mysql);
+
-  rc= mysql_query(my, "FLUSH PRIVILEGES");
+  FAIL_IF(!mysql_real_connect(mysql, hostname, username, password, schema,
+                         port, socketname, 0), mysql_error(my));
+
+  rc= mysql_query(mysql, "DROP TABLE IF EXISTS t1");
   check_mysql_rc(rc, mysql);
 
-  rc= mysql_options(mysql, MYSQL_READ_DEFAULT_GROUP, "conc-66");
+  rc= mysql_query(mysql, "CREATE TABLE t1 (a LONGBLOB)");
-  check_mysql_rc(rc, mysql);
-  rc= mysql_options(mysql, MYSQL_READ_DEFAULT_FILE, "./my.cnf");
   check_mysql_rc(rc, mysql);
 
-  rc= mysql_real_connect(mysql, hostname, NULL, NULL, schema,
+  rc= mysql_query(mysql, "INSERT INTO t1 VALUES (REPEAT('A', 1024 * 1024 * 20))");
-                         port, socketname, 0);
+  check_mysql_rc(rc, mysql); 
-  if (!rc) {
+
-    diag("Error: %s\n", mysql_error(mysql));
+  rc= mysql_query(mysql, "SELECT a FROM t1");
-    mysql_close(mysql);
+  check_mysql_rc(rc, mysql);
+
+  if (!(res= mysql_store_result(mysql)))
+  {
+    diag("Error: %s", mysql_error(mysql));
     return FAIL;
   }
+
+  row= mysql_fetch_row(res);
+  diag("Length: %ld", strlen(row[0]));
+  FAIL_IF(strlen(row[0]) != 1024 * 1024 * 20, "Wrong length");
+
+  mysql_free_result(res);
   mysql_close(mysql);
 
-  rc= mysql_query(my, "DROP USER 'conc-66'");
+  rc= mysql_query(my, "SET global max_allowed_packet=@a");
-  check_mysql_rc(rc, mysql);
+  check_mysql_rc(rc, my);
 
-  return OK; 
+  return OK;
 }
 
+
 static int basic_connect(MYSQL *mysql)
 {
   MYSQL_ROW row;
@@ -572,7 +600,6 @@ static int test_reconnect_maxpackage(MYSQL *my)
   memset(query + 8, 'A', max_packet);
   strcat(query, "' FROM DUAL");
 
-
   rc= mysql_query(mysql, query);
   free(query);
   if (!rc)
@@ -621,8 +648,8 @@ static int test_compressed(MYSQL *my)
 }
 
 struct my_tests_st my_tests[] = {
+  {"test_conc70", test_conc70, TEST_CONNECTION_DEFAULT, 0,  NULL,  NULL},
   {"test_conc68", test_conc68, TEST_CONNECTION_DEFAULT, 0,  NULL,  NULL},
-  {"test_conc66", test_conc66, TEST_CONNECTION_NEW, 0,  NULL,  NULL},
   {"test_compressed", test_compressed, TEST_CONNECTION_NONE, 0,  NULL,  NULL},
   {"test_reconnect_maxpackage", test_reconnect_maxpackage, TEST_CONNECTION_NONE, 0,  NULL,  NULL},
   {"basic_connect", basic_connect, TEST_CONNECTION_NONE, 0,  NULL,  NULL},

unittest/libmariadb/connection.c

@@ -57,7 +57,8 @@ static int test_conc66(MYSQL *my)
     diag("Error: %s", mysql_error(mysql));
     return FAIL;
   }
-  rc= mysql_query(my, "DROP USER conc66");
+  rc= mysql_query(my, "DROP USER conc66@localhost");
+
   check_mysql_rc(rc, my);
   mysql_close(mysql);
   return OK; 

unittest/libmariadb/misc.c

@@ -25,29 +25,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "ma_common.h"
 
 
-static int test_conc60(MYSQL *mysql)
-{
-  MYSQL_STMT *stmt= mysql_stmt_init(mysql);
-  char *stmtstr= "SELECT * FROM agendas";
-  int rc;
-  
-  rc= mysql_stmt_prepare(stmt, stmtstr, strlen(stmtstr));
-  check_stmt_rc(rc, stmt);
 
-  rc= mysql_stmt_execute(stmt);
-  check_stmt_rc(rc, stmt);
-
-  rc= mysql_stmt_store_result(stmt);
-  check_stmt_rc(rc, stmt);
-
-  diag("rows: %u", mysql_stmt_num_rows(stmt));
-
-  while (mysql_stmt_fetch(stmt));
-
-  mysql_stmt_close(stmt);
-
-  return(OK);
-}
 
 /*
   Bug#28075 "COM_DEBUG crashes mysqld"
@@ -984,7 +962,6 @@ static int test_connect_attrs(MYSQL *my)
 
 struct my_tests_st my_tests[] = {
   {"test_connect_attrs", test_connect_attrs, TEST_CONNECTION_DEFAULT, 0,  NULL, NULL},
-  {"test_conc60", test_conc60, TEST_CONNECTION_DEFAULT, 0,  NULL, NULL},
   {"test_conc49", test_conc49, TEST_CONNECTION_DEFAULT, 0,  NULL, NULL},
   {"test_bug28075", test_bug28075, TEST_CONNECTION_DEFAULT, 0,  NULL, NULL},
   {"test_bug28505", test_bug28505, TEST_CONNECTION_DEFAULT, 0,  NULL, NULL},