From: Firo Yang <firo.yang@suse.com>
To: marcelo.leitner@gmail.com, kuba@kernel.org, vyasevich@gmail.com,
nhorman@tuxdriver.com
Cc: mkubecek@suse.com, davem@davemloft.net, edumazet@google.com,
pabeni@redhat.com, linux-sctp@vger.kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
firogm@gmail.com, Firo Yang <firo.yang@suse.com>
Subject: [PATCH v3 1/1] sctp: sysctl: make extra pointers netns aware
Date: Fri, 9 Dec 2022 13:48:54 +0800 [thread overview]
Message-ID: <20221209054854.23889-1-firo.yang@suse.com> (raw)
Recently, a customer reported that from their container whose
net namespace is different to the host's init_net, they can't set
the container's net.sctp.rto_max to any value smaller than
init_net.sctp.rto_min.
For instance,
Host:
sudo sysctl net.sctp.rto_min
net.sctp.rto_min = 1000
Container:
echo 100 > /mnt/proc-net/sctp/rto_min
echo 400 > /mnt/proc-net/sctp/rto_max
echo: write error: Invalid argument
This is caused by the check made from this'commit 4f3fdf3bc59c
("sctp: add check rto_min and rto_max in sysctl")'
When validating the input value, it's always referring the boundary
value set for the init_net namespace.
Having container's rto_max smaller than host's init_net.sctp.rto_min
does make sense. Consider that the rto between two containers on the
same host is very likely smaller than it for two hosts.
So to fix this problem, as suggested by Marcelo, this patch makes the
extra pointers of rto_min, rto_max, pf_retrans, and ps_retrans point
to the corresponding variables from the newly created net namespace while
the new net namespace is being registered in sctp_sysctl_net_register.
Fixes: 4f3fdf3bc59c ("sctp: add check rto_min and rto_max in sysctl")
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Firo Yang <firo.yang@suse.com>
---
net/sctp/sysctl.c | 73 ++++++++++++++++++++++++++++-------------------
1 file changed, 44 insertions(+), 29 deletions(-)
v2 -> v3:
* Explicitly specifying indexes in sctp_net_table[].
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index b46a416787ec..43ebf090029d 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -84,17 +84,18 @@ static struct ctl_table sctp_table[] = {
{ /* sentinel */ }
};
+/* The following index defines are used in sctp_sysctl_net_register().
+ * If you add new items to the sctp_net_table, please ensure that
+ * the index values of these defines hold the same meaning indicated by
+ * their macro names when they appear in sctp_net_table.
+ */
+#define SCTP_RTO_MIN_IDX 0
+#define SCTP_RTO_MAX_IDX 1
+#define SCTP_PF_RETRANS_IDX 2
+#define SCTP_PS_RETRANS_IDX 3
+
static struct ctl_table sctp_net_table[] = {
- {
- .procname = "rto_initial",
- .data = &init_net.sctp.rto_initial,
- .maxlen = sizeof(unsigned int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ONE,
- .extra2 = &timer_max
- },
- {
+ [SCTP_RTO_MIN_IDX] = {
.procname = "rto_min",
.data = &init_net.sctp.rto_min,
.maxlen = sizeof(unsigned int),
@@ -103,7 +104,7 @@ static struct ctl_table sctp_net_table[] = {
.extra1 = SYSCTL_ONE,
.extra2 = &init_net.sctp.rto_max
},
- {
+ [SCTP_RTO_MAX_IDX] = {
.procname = "rto_max",
.data = &init_net.sctp.rto_max,
.maxlen = sizeof(unsigned int),
@@ -112,6 +113,33 @@ static struct ctl_table sctp_net_table[] = {
.extra1 = &init_net.sctp.rto_min,
.extra2 = &timer_max
},
+ [SCTP_PF_RETRANS_IDX] = {
+ .procname = "pf_retrans",
+ .data = &init_net.sctp.pf_retrans,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = &init_net.sctp.ps_retrans,
+ },
+ [SCTP_PS_RETRANS_IDX] = {
+ .procname = "ps_retrans",
+ .data = &init_net.sctp.ps_retrans,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &init_net.sctp.pf_retrans,
+ .extra2 = &ps_retrans_max,
+ },
+ {
+ .procname = "rto_initial",
+ .data = &init_net.sctp.rto_initial,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ONE,
+ .extra2 = &timer_max
+ },
{
.procname = "rto_alpha_exp_divisor",
.data = &init_net.sctp.rto_alpha,
@@ -207,24 +235,6 @@ static struct ctl_table sctp_net_table[] = {
.extra1 = SYSCTL_ONE,
.extra2 = SYSCTL_INT_MAX,
},
- {
- .procname = "pf_retrans",
- .data = &init_net.sctp.pf_retrans,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ZERO,
- .extra2 = &init_net.sctp.ps_retrans,
- },
- {
- .procname = "ps_retrans",
- .data = &init_net.sctp.ps_retrans,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = &init_net.sctp.pf_retrans,
- .extra2 = &ps_retrans_max,
- },
{
.procname = "sndbuf_policy",
.data = &init_net.sctp.sndbuf_policy,
@@ -586,6 +596,11 @@ int sctp_sysctl_net_register(struct net *net)
for (i = 0; table[i].data; i++)
table[i].data += (char *)(&net->sctp) - (char *)&init_net.sctp;
+ table[SCTP_RTO_MIN_IDX].extra2 = &net->sctp.rto_max;
+ table[SCTP_RTO_MAX_IDX].extra1 = &net->sctp.rto_min;
+ table[SCTP_PF_RETRANS_IDX].extra2 = &net->sctp.ps_retrans;
+ table[SCTP_PS_RETRANS_IDX].extra1 = &net->sctp.pf_retrans;
+
net->sctp.sysctl_header = register_net_sysctl(net, "net/sctp", table);
if (net->sctp.sysctl_header == NULL) {
kfree(table);
--
2.26.2
next reply other threads:[~2022-12-09 5:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-09 5:48 Firo Yang [this message]
2022-12-12 21:00 ` [PATCH v3 1/1] sctp: sysctl: make extra pointers netns aware patchwork-bot+netdevbpf
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=20221209054854.23889-1-firo.yang@suse.com \
--to=firo.yang@suse.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=firogm@gmail.com \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sctp@vger.kernel.org \
--cc=marcelo.leitner@gmail.com \
--cc=mkubecek@suse.com \
--cc=netdev@vger.kernel.org \
--cc=nhorman@tuxdriver.com \
--cc=pabeni@redhat.com \
--cc=vyasevich@gmail.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).