From: "Morten Brørup" <mb@smartsharesystems.com>
To: "fengchengwen" <fengchengwen@huawei.com>,
"Stephen Hemminger" <stephen@networkplumber.org>,
"Bruce Richardson" <bruce.richardson@intel.com>
Cc: <thomas@monjalon.net>, <ferruh.yigit@xilinx.com>,
<kevin.laatz@intel.com>, <andrew.rybchenko@oktetlabs.ru>,
<jerinj@marvell.com>, <sachin.saxena@oss.nxp.com>,
<hemant.agrawal@nxp.com>, <dev@dpdk.org>,
"Ciara Power" <ciara.power@intel.com>
Subject: RE: [PATCH v2 1/5] telemetry: escape special char when tel string
Date: Sat, 18 Jun 2022 11:59:03 +0200 [thread overview]
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35D8713F@smartserver.smartshare.dk> (raw)
In-Reply-To: <507d1942-868b-4e60-6921-6b420190e5de@huawei.com>
+CC: Ciara Power, Telemetry library maintainer
> From: fengchengwen [mailto:fengchengwen@huawei.com]
> Sent: Saturday, 18 June 2022 05.52
>
> On 2022/6/18 1:05, Stephen Hemminger wrote:
> > On Fri, 17 Jun 2022 12:25:04 +0100
> > Bruce Richardson <bruce.richardson@intel.com> wrote:
> >
> >> On Fri, Jun 17, 2022 at 01:16:08PM +0200, Morten Brørup wrote:
> >>>> From: Chengwen Feng [mailto:fengchengwen@huawei.com]
> >>>> Sent: Friday, 17 June 2022 11.46
> >>>>
> >>>> This patch supports escape special characters (including:
> \",\\,/,\b,
> >>>> /f,/n,/r,/t) when telemetry string.
> >>>> This patch is used to support telemetry xxx-dump commands which
> the
> >>>> string may include special characters.
> >>>>
> >>>> Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
> >>>> ---
> >>>> lib/telemetry/telemetry.c | 96
> +++++++++++++++++++++++++++++++++++++--
> >>>> 1 file changed, 93 insertions(+), 3 deletions(-)
> >>>>
> >>>> diff --git a/lib/telemetry/telemetry.c b/lib/telemetry/telemetry.c
> >>>> index c6fd03a5ab..0f762f633e 100644
> >>>> --- a/lib/telemetry/telemetry.c
> >>>> +++ b/lib/telemetry/telemetry.c
> >>>> @@ -215,6 +215,94 @@ container_to_json(const struct rte_tel_data
> *d,
> >>>> char *out_buf, size_t buf_len)
> >>>> return used;
> >>>> }
> >>>>
> >>>> +static bool
> >>>> +json_is_special_char(char ch)
> >>>> +{
> >>>> + static unsigned char is_spec[256] = { 0 };
> >>>> + static bool init_once;
> >>>> +
> >>>> + if (!init_once) {
> >>>> + is_spec['\"'] = 1;
> >>>> + is_spec['\\'] = 1;
> >>>> + is_spec['/'] = 1;
> >>>> + is_spec['\b'] = 1;
> >>>> + is_spec['\f'] = 1;
> >>>> + is_spec['\n'] = 1;
> >>>> + is_spec['\r'] = 1;
> >>>> + is_spec['\t'] = 1;
> >>>> + init_once = true;
> >>>> + }
> >>>> +
> >>>> + return (bool)is_spec[(unsigned char)ch];
> >>>> +}
> >>
> >> According to the json spec at [1], the characters that need to be
> escaped
> >> are:
> >> a) any characters <0x20
> >> b) inverted commas/quote character \"
> >> c) the "reverse solidus character", better known to you and I as the
> >> back-slash.
> >>
> >> Therefore, I think this table generation could be simplified, but
> also
> >> expanded using this. For completeness we should also see about
> handling all
> >> control characters if they are encountered.
> >>
> >> [1] https://www.rfc-editor.org/rfc/rfc8259.txt
> >>
> >> /Bruce
> >
> > Since it is trivial could be initializer?
> >
> > static const uint8_t is_spec[256] = {
> > [0 ... 0x20] = 1,
> > ['\"' ] = 1,
> > ['\\' ] = 1,
> > ['/'] = 1,
> >
> > etc
> >
> > Or we could change the telemetry API to disallow control characters?
>
> I was thinking about converting 0~0x20, but I don't think there's a
> scenario.
>
> I prefer change the telemetry API to disallow control characters, and
> this may not
> be a violation of the ABI, if yes, the dpdk-telemetry.py will returns
> an error.
I agree with Chengwen Feng. The telemetry data type is STRING, not BLOB.
So we need to define exactly what the STRING type contains.
I hope we can all agree that control characters should be disallowed.
The more complicated question is: Do we want to use the ASCII character set only, or do we want to use UTF-8 encoded Unicode?
Personally, think UTF-8 encoded Unicode is more future proof, and would vote for that.
But I wouldn't reject limiting it to ASCII, and perhaps in the future introduce another data type for UTF-8 strings.
UTF-8 is the modern choice, but it is incompatible with old stuff, e.g. many SNMP MIBs.
>
> So I think we could add declaring and checking functions to make sure
> telemetry string
> do not allow control characters.
Input validation (when storing a string in the telemetry database) has a performance cost, so it could be a compile time debug option, like the memory cookies and mbuf integrity checks. Just a thought.
next prev parent reply other threads:[~2022-06-18 9:59 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-15 7:39 [PATCH 0/5] support telemetry dump dev Chengwen Feng
2022-06-15 7:39 ` [PATCH 1/5] usertools: use non-strict when json-loads in telemetry Chengwen Feng
2022-06-15 13:54 ` Morten Brørup
2022-06-15 16:54 ` Bruce Richardson
2022-06-15 18:01 ` Morten Brørup
2022-06-15 20:09 ` Morten Brørup
2022-06-15 7:39 ` [PATCH 2/5] dmadev: support telemetry dump dmadev Chengwen Feng
2022-06-15 7:39 ` [PATCH 3/5] eventdev: support telemetry dump eventdev Chengwen Feng
2022-06-15 7:39 ` [PATCH 4/5] rawdev: support telemetry dump rawdev Chengwen Feng
2022-06-15 7:39 ` [PATCH 5/5] ethdev: support telemetry private dump Chengwen Feng
2022-06-15 20:15 ` [PATCH 0/5] support telemetry dump dev Morten Brørup
2022-06-16 8:19 ` Bruce Richardson
2022-06-16 9:00 ` Morten Brørup
2022-06-17 9:46 ` [PATCH v2 0/5] support telemetry dump Chengwen Feng
2022-06-17 9:46 ` [PATCH v2 1/5] telemetry: escape special char when tel string Chengwen Feng
2022-06-17 11:16 ` Morten Brørup
2022-06-17 11:25 ` Bruce Richardson
2022-06-17 17:05 ` Stephen Hemminger
2022-06-18 3:52 ` fengchengwen
2022-06-18 9:59 ` Morten Brørup [this message]
2022-06-22 7:57 ` Power, Ciara
2022-06-22 9:19 ` Bruce Richardson
2022-06-23 16:45 ` Bruce Richardson
2022-06-17 11:27 ` Bruce Richardson
2022-06-17 9:46 ` [PATCH v2 2/5] dmadev: support telemetry dump dmadev Chengwen Feng
2022-06-17 9:46 ` [PATCH v2 3/5] eventdev: support telemetry dump eventdev Chengwen Feng
2022-06-17 9:46 ` [PATCH v2 4/5] rawdev: support telemetry dump rawdev Chengwen Feng
2022-06-17 9:46 ` [PATCH v2 5/5] ethdev: support telemetry private dump Chengwen Feng
2022-09-13 2:44 ` [PATCH v3 0/4] support telemetry dump dev Chengwen Feng
2022-09-13 2:44 ` [PATCH v3 1/4] dmadev: support telemetry dump dmadev Chengwen Feng
2022-09-13 2:44 ` [PATCH v3 2/4] eventdev: support telemetry dump eventdev Chengwen Feng
2022-09-13 2:44 ` [PATCH v3 3/4] rawdev: support telemetry dump rawdev Chengwen Feng
2022-09-13 2:44 ` [PATCH v3 4/4] ethdev: support telemetry private dump Chengwen Feng
2022-09-13 7:13 ` [PATCH v4 0/4] support telemetry dump dev Chengwen Feng
2022-09-13 7:13 ` [PATCH v4 1/4] dmadev: support telemetry dump dmadev Chengwen Feng
2022-09-13 7:13 ` [PATCH v4 2/4] eventdev: support telemetry dump eventdev Chengwen Feng
2022-09-13 7:13 ` [PATCH v4 3/4] rawdev: support telemetry dump rawdev Chengwen Feng
2022-09-13 7:13 ` [PATCH v4 4/4] ethdev: support telemetry private dump Chengwen Feng
2022-10-03 7:28 ` [PATCH v4 0/4] support telemetry dump dev David Marchand
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