DPDK patches and discussions
 help / color / mirror / Atom feed
From: Bruce Richardson <bruce.richardson@intel.com>
To: "Wiles, Keith" <keith.wiles@intel.com>
Cc: "Power, Ciara" <ciara.power@intel.com>, dev <dev@dpdk.org>,
	"Laatz, Kevin" <kevin.laatz@intel.com>,
	"Pattan, Reshma" <reshma.pattan@intel.com>,
	"jerinjacobk@gmail.com" <jerinjacobk@gmail.com>,
	"david.marchand@redhat.com" <david.marchand@redhat.com>,
	"mb@smartsharesystems.com" <mb@smartsharesystems.com>,
	"thomas@monjalon.net" <thomas@monjalon.net>
Subject: Re: [dpdk-dev] [PATCH v2 06/16] telemetry: add utility functions for creating json
Date: Thu, 9 Apr 2020 09:19:18 +0100
Message-ID: <20200409081918.GA605@bricha3-MOBL.ger.corp.intel.com> (raw)
In-Reply-To: <C3A15A64-6BCB-4501-A86E-CC1BFB627340@intel.com>

On Wed, Apr 08, 2020 at 07:12:57PM +0100, Wiles, Keith wrote:
> 
> 
> > On Apr 8, 2020, at 11:49 AM, Power, Ciara <ciara.power@intel.com> wrote:
> >
> > From: Bruce Richardson <bruce.richardson@intel.com>
> >
> > The functions added in this patch will make it easier for applications
> > to build up correct JSON responses to telemetry requests.
> >
> > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> > ---
> > lib/librte_telemetry/Makefile             |   1 +
> > lib/librte_telemetry/meson.build          |   2 +-
> > lib/librte_telemetry/rte_telemetry.h      |   1 +
> > lib/librte_telemetry/rte_telemetry_json.h | 205 ++++++++++++++++++++++
> > 4 files changed, 208 insertions(+), 1 deletion(-)
> > create mode 100644 lib/librte_telemetry/rte_telemetry_json.h
<snip>
> > +/**
> > + * @internal
> > + *
> > + * Copies a value into a buffer if the buffer has enough available space.
> > + * Nothing written to buffer if an overflow ocurs.
> > + * This function is not for use for values larger than 1k.
> > + *
> > + * @param buf
> > + * Buffer for data to be appended to.
> > + * @param len
> > + * Length of buffer.
> > + * @param format
> > + * Format string.
> > + * @param ...
> > + * Optional arguments that may be required by the format string.
> > + *
> > + * @return
> > + *  Number of characters added to buffer
> > + */
> > +__attribute__((__format__(__printf__, 3, 4)))
> > +static inline int
> > +__json_snprintf(char *buf, const int len, const char *format, ...)
> > +{
> > +char tmp[1024];
> > +va_list ap;
> > +int ret;
> > +
> > +va_start(ap, format);
> > +ret = vsnprintf(tmp, sizeof(tmp), format, ap);
> > +va_end(ap);
> 
> Would strlcpy(buf, tmp, len); reduce the test below? vsnprintf() writes at most size bytes including the ‘\0’ to the buffer. Maybe able to reduce the code to this:
> 
> return strlcpy(buf, tmp, len);// strlcpy returns the total length of buf.
> 
> This means the ret is not really required, unless I missed something.
> 
> > +if (ret > 0 && ret < (int)sizeof(tmp) && ret < len) {
> > +strcpy(buf, tmp);
> > +return ret;
> > +}
> > +return 0; /* nothing written or modified */
> > +}
> > +
The intent here is that the buffer remains unmodified and the function
returns zero in the case that the printf fails to work. Truncation would
likely leave us with invalid json, so it's all or nothing, which is why we
can't just take the snprintf or strlcpy. [On overflow they still modify the
buffer, which means any closing "]" or "}" in the json would be
overwritten.]

/Bruce

  reply	other threads:[~2020-04-09  8:19 UTC|newest]

Thread overview: 130+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-19 17:18 [dpdk-dev] [PATCH 00/12] update and simplify telemetry library Ciara Power
2020-03-19 17:18 ` [dpdk-dev] [PATCH 01/12] telemetry: move code to metrics for later reuse Ciara Power
2020-03-19 17:18 ` [dpdk-dev] [PATCH 02/12] metrics: reduce code taken from telemetry Ciara Power
2020-03-19 17:18 ` [dpdk-dev] [PATCH 03/12] telemetry: invert dependency on metrics Ciara Power
2020-03-19 17:18 ` [dpdk-dev] [PATCH 04/12] telemetry: introduce new telemetry functionality Ciara Power
2020-03-19 17:19 ` [dpdk-dev] [PATCH 05/12] ethdev: add callback support for telemetry Ciara Power
2020-03-19 17:19 ` [dpdk-dev] [PATCH 06/12] usertools: add new telemetry python script Ciara Power
2020-03-19 17:19 ` [dpdk-dev] [PATCH 07/12] rawdev: add callback support for telemetry Ciara Power
2020-03-19 17:19 ` [dpdk-dev] [PATCH 08/12] examples/l3fwd-power: enable use of new telemetry Ciara Power
2020-03-19 17:19 ` [dpdk-dev] [PATCH 09/12] telemetry: introduce telemetry backward compatibility Ciara Power
2020-03-19 17:19 ` [dpdk-dev] [PATCH 10/12] telemetry: remove existing telemetry files Ciara Power
2020-03-19 17:19 ` [dpdk-dev] [PATCH 11/12] lib: add telemetry as eal dependency Ciara Power
2020-03-20 12:03   ` Jerin Jacob
2020-03-20 13:50     ` Bruce Richardson
2020-03-19 17:19 ` [dpdk-dev] [PATCH 12/12] eal: add eal telemetry callbacks Ciara Power
2020-04-01 15:42 ` [dpdk-dev] [PATCH 00/12] update and simplify telemetry library David Marchand
2020-04-01 16:16   ` Bruce Richardson
2020-04-02  8:30     ` Morten Brørup
2020-04-02  9:38       ` Thomas Monjalon
2020-04-01 16:48 ` Wiles, Keith
2020-04-02 10:09   ` Bruce Richardson
2020-04-08 16:49 ` [dpdk-dev] [PATCH v2 00/16] " Ciara Power
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 01/16] build: add arch-specific header path to global includes Ciara Power
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 02/16] telemetry: move code to metrics for later reuse Ciara Power
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 03/16] metrics: reduce code taken from telemetry Ciara Power
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 04/16] telemetry: invert dependency on metrics Ciara Power
2020-04-10 16:15     ` Pattan, Reshma
2020-04-15  9:50       ` Power, Ciara
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 05/16] telemetry: introduce new telemetry functionality Ciara Power
2020-04-08 17:56     ` Wiles, Keith
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 06/16] telemetry: add utility functions for creating json Ciara Power
2020-04-08 18:12     ` Wiles, Keith
2020-04-09  8:19       ` Bruce Richardson [this message]
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 07/16] app/test: add telemetry json tests Ciara Power
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 08/16] ethdev: add callback support for telemetry Ciara Power
2020-04-08 18:16     ` Wiles, Keith
2020-04-09  8:20       ` Bruce Richardson
2020-04-10  9:57         ` [dpdk-dev] [PATCH v2 08/16] ethdev: add callback support fortelemetry Morten Brørup
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 09/16] usertools: add new telemetry python script Ciara Power
2020-04-10  9:43     ` Pattan, Reshma
2020-04-10  9:54       ` Bruce Richardson
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 10/16] rawdev: add callback support for telemetry Ciara Power
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 11/16] examples/l3fwd-power: enable use of new telemetry Ciara Power
2020-04-10  8:42     ` Pattan, Reshma
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 12/16] telemetry: introduce telemetry backward compatibility Ciara Power
2020-04-10 17:00     ` Pattan, Reshma
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 13/16] telemetry: remove existing telemetry files Ciara Power
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 14/16] lib: add telemetry as eal dependency Ciara Power
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 15/16] eal: add eal telemetry callbacks Ciara Power
2020-04-08 16:49   ` [dpdk-dev] [PATCH v2 16/16] doc: update telemetry documentation Ciara Power
2020-04-08 18:03   ` [dpdk-dev] [PATCH v2 00/16] update and simplify telemetry library Thomas Monjalon
2020-04-09  9:19     ` Bruce Richardson
2020-04-09  9:37       ` Thomas Monjalon
2020-04-10 14:39         ` Wiles, Keith
2020-04-10 14:51           ` Thomas Monjalon
2020-04-10 14:59             ` Wiles, Keith
2020-04-23 10:30         ` Luca Boccassi
2020-04-23 10:44           ` Thomas Monjalon
2020-04-23 11:46             ` Luca Boccassi
2020-04-10 10:49   ` Morten Brørup
2020-04-10 14:21     ` Wiles, Keith
2020-04-10 18:06       ` [dpdk-dev] [PATCH v2 00/16] update and simplify telemetrylibrary Morten Brørup
2020-04-20 13:18         ` Bruce Richardson
2020-04-20 14:55           ` [dpdk-dev] [PATCH v2 00/16] update and simplifytelemetrylibrary Morten Brørup
2020-04-21 12:39 ` [dpdk-dev] [PATCH v3 00/17] update and simplify telemetry library Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 01/17] build: add arch-specific header path to global includes Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 02/17] telemetry: move code to metrics for later reuse Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 03/17] metrics: reduce code taken from telemetry Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 04/17] telemetry: invert dependency on metrics Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 05/17] telemetry: introduce new telemetry functionality Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 06/17] telemetry: add utility functions for creating json Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 07/17] app/test: add telemetry json tests Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 08/17] ethdev: add callback support for telemetry Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 09/17] usertools: add new telemetry python script Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 10/17] rawdev: add callback support for telemetry Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 11/17] examples/l3fwd-power: enable use of new telemetry Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 12/17] telemetry: introduce telemetry backward compatibility Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 13/17] telemetry: remove existing telemetry files Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 14/17] lib: add telemetry as eal dependency Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 15/17] eal: remove rte-option infrastructure Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 16/17] eal: add eal telemetry callbacks Ciara Power
2020-04-21 12:39   ` [dpdk-dev] [PATCH v3 17/17] doc: update telemetry documentation Ciara Power
2020-04-24 12:41 ` [dpdk-dev] [PATCH v4 00/18] update and simplify telemetry library Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 01/18] build: add arch-specific header path to global includes Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 02/18] telemetry: move code to metrics for later reuse Ciara Power
2020-04-24 15:29     ` Stephen Hemminger
2020-04-24 15:49       ` Bruce Richardson
2020-04-27  9:53       ` Power, Ciara
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 03/18] metrics: reduce code taken from telemetry Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 04/18] telemetry: invert dependency on metrics Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 05/18] telemetry: add utility functions for creating json Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 06/18] telemetry: introduce new telemetry functionality Ciara Power
2020-04-24 20:50     ` Wiles, Keith
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 07/18] telemetry: add functions for returning callback data Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 08/18] telemetry: add default callback commands Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 09/18] usertools: add new telemetry python script Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 10/18] ethdev: add callback support for telemetry Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 11/18] rawdev: " Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 12/18] examples/l3fwd-power: enable use of new telemetry Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 13/18] telemetry: introduce telemetry backward compatibility Ciara Power
2020-04-24 20:59     ` Wiles, Keith
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 14/18] telemetry: remove existing telemetry files Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 15/18] lib: add telemetry as eal dependency Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 16/18] eal: remove rte-option infrastructure Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 17/18] eal: add eal telemetry callbacks Ciara Power
2020-04-24 12:41   ` [dpdk-dev] [PATCH v4 18/18] doc: update telemetry documentation Ciara Power
2020-04-24 21:09   ` [dpdk-dev] [PATCH v4 00/18] update and simplify telemetry library Wiles, Keith
2020-04-30 16:01 ` [dpdk-dev] [PATCH v5 " Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 01/18] build: add arch-specific header path to global includes Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 02/18] telemetry: move code to metrics for later reuse Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 03/18] metrics: reduce code taken from telemetry Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 04/18] telemetry: invert dependency on metrics Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 05/18] telemetry: add utility functions for creating json Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 06/18] telemetry: introduce new telemetry functionality Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 07/18] telemetry: add functions for returning callback data Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 08/18] telemetry: add default callback commands Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 09/18] usertools: add new telemetry python script Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 10/18] ethdev: add callback support for telemetry Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 11/18] rawdev: " Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 12/18] examples/l3fwd-power: enable use of new telemetry Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 13/18] telemetry: introduce telemetry backward compatibility Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 14/18] telemetry: remove existing telemetry files Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 15/18] lib: add telemetry as eal dependency Ciara Power
2020-05-10 22:29     ` Thomas Monjalon
2020-05-11  8:41       ` Bruce Richardson
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 16/18] eal: remove rte-option infrastructure Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 17/18] eal: add eal telemetry callbacks Ciara Power
2020-04-30 16:01   ` [dpdk-dev] [PATCH v5 18/18] doc: update telemetry documentation Ciara Power
2020-05-01 14:41   ` [dpdk-dev] [PATCH v5 00/18] update and simplify telemetry library Wiles, Keith
2020-05-10 22:41   ` Thomas Monjalon

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200409081918.GA605@bricha3-MOBL.ger.corp.intel.com \
    --to=bruce.richardson@intel.com \
    --cc=ciara.power@intel.com \
    --cc=david.marchand@redhat.com \
    --cc=dev@dpdk.org \
    --cc=jerinjacobk@gmail.com \
    --cc=keith.wiles@intel.com \
    --cc=kevin.laatz@intel.com \
    --cc=mb@smartsharesystems.com \
    --cc=reshma.pattan@intel.com \
    --cc=thomas@monjalon.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

DPDK patches and discussions

This inbox may be cloned and mirrored by anyone:

	git clone --mirror http://inbox.dpdk.org/dev/0 dev/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 dev dev/ http://inbox.dpdk.org/dev \
		dev@dpdk.org
	public-inbox-index dev

Example config snippet for mirrors.
Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.dev


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git