All of lore.kernel.org
 help / color / mirror / Atom feed
From: Guillaume Nault <gnault@redhat.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: netdev@vger.kernel.org
Subject: [PATCH iproute2] utils: bump max args number to 256 for batch files
Date: Tue, 1 Jun 2021 19:09:31 +0200	[thread overview]
Message-ID: <4a0fcf72130d3ef5c4ca91b518f66ac6449cf57f.1622565590.git.gnault@redhat.com> (raw)

Large tc filters can have many arguments. For example the following
filter matches the first 7 MPLS LSEs, pops all of them, then updates
the Ethernet header and redirects the resulting packet to eth1.

filter add dev eth0 ingress handle 44 priority 100 \
  protocol mpls_uc flower mpls                     \
    lse depth 1 label 1040076 tc 4 bos 0 ttl 175   \
    lse depth 2 label 89648 tc 2 bos 0 ttl 9       \
    lse depth 3 label 63417 tc 5 bos 0 ttl 185     \
    lse depth 4 label 593135 tc 5 bos 0 ttl 67     \
    lse depth 5 label 857021 tc 0 bos 0 ttl 181    \
    lse depth 6 label 239239 tc 1 bos 0 ttl 254    \
    lse depth 7 label 30 tc 7 bos 1 ttl 237        \
  action mpls pop protocol mpls_uc pipe            \
  action mpls pop protocol mpls_uc pipe            \
  action mpls pop protocol mpls_uc pipe            \
  action mpls pop protocol mpls_uc pipe            \
  action mpls pop protocol mpls_uc pipe            \
  action mpls pop protocol mpls_uc pipe            \
  action mpls pop protocol ipv6 pipe               \
  action vlan pop_eth pipe                         \
  action vlan push_eth                             \
    dst_mac 00:00:5e:00:53:7e                      \
    src_mac 00:00:5e:00:53:03 pipe                 \
  action mirred egress redirect dev eth1

This filter has 149 arguments, so it can't be used with tc -batch
which is limited to a 100.

Let's bump the limit to the next power of 2. That should leave a lot of
room for big batch commands.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
---

Note: I have no production use case for MPLS stacks with 7 LSEs at the
      moment, but 7 is the maximum depth the flow dissector can handle,
      and having the possibility to express such rules with tc -batch
      would help testing the kernel API (writing scripts that generate
      filters, without worrying about the 100 parameters limit).

 lib/utils.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/utils.c b/lib/utils.c
index 93ae0c55..d5496e45 100644
--- a/lib/utils.c
+++ b/lib/utils.c
@@ -1714,10 +1714,10 @@ int do_batch(const char *name, bool force,
 
 	cmdlineno = 0;
 	while (getcmdline(&line, &len, stdin) != -1) {
-		char *largv[100];
+		char *largv[256];
 		int largc;
 
-		largc = makeargs(line, largv, 100);
+		largc = makeargs(line, largv, 256);
 		if (!largc)
 			continue;	/* blank line */
 
-- 
2.21.3


             reply	other threads:[~2021-06-01 17:09 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-01 17:09 Guillaume Nault [this message]
2021-06-09 23:59 ` [PATCH iproute2] utils: bump max args number to 256 for batch files Stephen Hemminger
2021-06-10  7:58   ` Guillaume Nault
2021-06-10 23:17     ` Stephen Hemminger
2021-06-11  9:51       ` Guillaume Nault

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=4a0fcf72130d3ef5c4ca91b518f66ac6449cf57f.1622565590.git.gnault@redhat.com \
    --to=gnault@redhat.com \
    --cc=netdev@vger.kernel.org \
    --cc=stephen@networkplumber.org \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.