From: "Singh, Jasvinder" <jasvinder.singh@intel.com>
To: Gadre Nayan <gadrenayan@gmail.com>, "users@dpdk.org" <users@dpdk.org>
Subject: Re: [dpdk-users] Tracking pipeline ports.
Date: Mon, 18 Jul 2016 17:09:37 +0000 [thread overview]
Message-ID: <54CBAA185211B4429112C315DA58FF6DE7E38F@IRSMSX103.ger.corp.intel.com> (raw)
In-Reply-To: <CAKJ7aR5dL83E+jJHGY_2wZteYO_cL=jfN6v7Lid6A275L=8j8g@mail.gmail.com>
> -----Original Message-----
> From: users [mailto:users-bounces@dpdk.org] On Behalf Of Gadre Nayan
> Sent: Monday, July 18, 2016 4:42 PM
> To: users@dpdk.org
> Subject: [dpdk-users] Tracking pipeline ports.
>
> Hi,
>
> I wanted to understand the purpose of the f_track function.
>
> In the IP_pipeline example there are 2 instances where the f_track is used.
>
> 1. pipeline_firewall:
> static int pipeline_firewall_track(void *pipeline, __rte_unused uint32_t
> port_in,
> uint32_t *port_out)
> {
> struct pipeline *p = (struct pipeline *) pipeline;
>
> /* Check input arguments */
> if ((p == NULL) ||
> (port_in >= p->n_ports_in) ||
> (port_out == NULL))
> return -1;
>
> if (p->n_ports_in == 1) {
> *port_out = 0;
> return 0;
> }
>
> return -1;
> }
>
> 2. Passthrough:
>
> static int
> pipeline_passthrough_track(void *pipeline, uint32_t port_in, uint32_t
> *port_out) {
> struct pipeline *p = (struct pipeline *) pipeline;
>
> /* Check input arguments */
> if ((p == NULL) ||
> (port_in >= p->n_ports_in) ||
> (port_out == NULL))
> return -1;
>
> *port_out = port_in / p->n_ports_in;
> return 0;
> }
The f_track function is used in all the pipeline instances. All pipeline instances except passthrough pipeline implements default version of the f_track function. The pipelines such as pass-through allows tracking to be performaned through them becasue of straightforward connections between their input and output ports, while pipelines like flow-classifications, firewall fails the tracking because of the dependency on the table rule set.
> 1. What is a actual use of this function ?
> Quoting the documentation:
> "In some cases, it is useful for a pipeline instance to get application level
> information related to pipeline connectivity, such as to identify the output
> link (e.g. physical NIC port) where one of its output ports connected, either
> directly or indirectly by traversing other pipeline instances."
This function is implemented as the part of tracking mechanism for identifying the physical nic port where a specific output ports of the routing pipeline are eventually connected. Tracking could involve traversing the other intermediate pipelines before actually getting to physical nic ports. As a result of tracking, routing pipeline can use the real MAC addresses of the network interfaces instead of using hardcoded default value for building the table entries . Furthermore, It also adds support for automatic route updates (add/remove routing entries) when linked physical NIC ports change their state (up/down).
> 2. The 1st condition check remains same in both. But in pass-through
> port_out is assigned some value. what does this mean ?
These are older version of the functions, please check with latest code.
Jasvinder
prev parent reply other threads:[~2016-07-18 17:09 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-18 15:42 Gadre Nayan
2016-07-18 17:09 ` Singh, Jasvinder [this message]
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