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diff --git a/doc/guides/sample_app_ug/cmd_line.rst b/doc/guides/sample_app_ug/cmd_line.rst new file mode 100644 index 00000000..02a295ff --- /dev/null +++ b/doc/guides/sample_app_ug/cmd_line.rst @@ -0,0 +1,202 @@ +.. BSD LICENSE + Copyright(c) 2010-2014 Intel Corporation. All rights reserved. + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions + are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in + the documentation and/or other materials provided with the + distribution. + * Neither the name of Intel Corporation nor the names of its + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +Command Line Sample Application +=============================== + +This chapter describes the Command Line sample application that +is part of the Data Plane Development Kit (DPDK). + +Overview +-------- + +The Command Line sample application is a simple application that +demonstrates the use of the command line interface in the DPDK. +This application is a readline-like interface that can be used +to debug a DPDK application, in a Linux* application environment. + +.. note:: + + The rte_cmdline library should not be used in production code since + it is not validated to the same standard as other DPDK libraries. + See also the "rte_cmdline library should not be used in production code due to limited testing" item + in the "Known Issues" section of the Release Notes. + +The Command Line sample application supports some of the features of the GNU readline library such as, completion, +cut/paste and some other special bindings that make configuration and debug faster and easier. + +The application shows how the rte_cmdline application can be extended to handle a list of objects. +There are three simple commands: + +* add obj_name IP: Add a new object with an IP/IPv6 address associated to it. + +* del obj_name: Delete the specified object. + +* show obj_name: Show the IP associated with the specified object. + +.. note:: + + To terminate the application, use **Ctrl-d**. + +Compiling the Application +------------------------- + +#. Go to example directory: + + .. code-block:: console + + export RTE_SDK=/path/to/rte_sdk + cd ${RTE_SDK}/examples/cmdline + +#. Set the target (a default target is used if not specified). For example: + + .. code-block:: console + + export RTE_TARGET=x86_64-native-linuxapp-gcc + + Refer to the *DPDK Getting Started Guide* for possible RTE_TARGET values. + +#. Build the application: + + .. code-block:: console + + make + +Running the Application +----------------------- + +To run the application in linuxapp environment, issue the following command: + +.. code-block:: console + + $ ./build/cmdline -c f -n 4 + +Refer to the *DPDK Getting Started Guide* for general information on running applications +and the Environment Abstraction Layer (EAL) options. + +Explanation +----------- + +The following sections provide some explanation of the code. + +EAL Initialization and cmdline Start +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The first task is the initialization of the Environment Abstraction Layer (EAL). +This is achieved as follows: + +.. code-block:: c + + int main(int argc, char **argv) + { + ret = rte_eal_init(argc, argv); + if (ret < 0) + rte_panic("Cannot init EAL\n"); + +Then, a new command line object is created and started to interact with the user through the console: + +.. code-block:: c + + cl = cmdline_stdin_new(main_ctx, "example> "); + cmdline_interact(cl); + cmdline_stdin_exit(cl); + +The cmd line_interact() function returns when the user types **Ctrl-d** and in this case, +the application exits. + +Defining a cmdline Context +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +A cmdline context is a list of commands that are listed in a NULL-terminated table, for example: + +.. code-block:: c + + cmdline_parse_ctx_t main_ctx[] = { + (cmdline_parse_inst_t *) &cmd_obj_del_show, + (cmdline_parse_inst_t *) &cmd_obj_add, + (cmdline_parse_inst_t *) &cmd_help, + NULL, + }; + +Each command (of type cmdline_parse_inst_t) is defined statically. +It contains a pointer to a callback function that is executed when the command is parsed, +an opaque pointer, a help string and a list of tokens in a NULL-terminated table. + +The rte_cmdline application provides a list of pre-defined token types: + +* String Token: Match a static string, a list of static strings or any string. + +* Number Token: Match a number that can be signed or unsigned, from 8-bit to 32-bit. + +* IP Address Token: Match an IPv4 or IPv6 address or network. + +* Ethernet* Address Token: Match a MAC address. + +In this example, a new token type obj_list is defined and implemented +in the parse_obj_list.c and parse_obj_list.h files. + +For example, the cmd_obj_del_show command is defined as shown below: + +.. code-block:: c + + struct cmd_obj_add_result { + cmdline_fixed_string_t action; + cmdline_fixed_string_t name; + struct object *obj; + }; + + static void cmd_obj_del_show_parsed(void *parsed_result, struct cmdline *cl, attribute ((unused)) void *data) + { + /* ... */ + } + + cmdline_parse_token_string_t cmd_obj_action = TOKEN_STRING_INITIALIZER(struct cmd_obj_del_show_result, action, "show#del"); + + parse_token_obj_list_t cmd_obj_obj = TOKEN_OBJ_LIST_INITIALIZER(struct cmd_obj_del_show_result, obj, &global_obj_list); + + cmdline_parse_inst_t cmd_obj_del_show = { + .f = cmd_obj_del_show_parsed, /* function to call */ + .data = NULL, /* 2nd arg of func */ + .help_str = "Show/del an object", + .tokens = { /* token list, NULL terminated */ + (void *)&cmd_obj_action, + (void *)&cmd_obj_obj, + NULL, + }, + }; + +This command is composed of two tokens: + +* The first token is a string token that can be show or del. + +* The second token is an object that was previously added using the add command in the global_obj_list variable. + +Once the command is parsed, the rte_cmdline application fills a cmd_obj_del_show_result structure. +A pointer to this structure is given as an argument to the callback function and can be used in the body of this function. |