[PATCH net-next] docs: net: fix outdated default values of four sysctls

[Gopal Malaviya <gopalmalaviya53@gmail.com>]

The defaults documented in ip-sysctl.rst for four sysctls differ from
the values the kernel actually uses:

  sysctl                  documented  actual
  cipso_rbm_strictvalid   0           1
  flowlabel_state_ranges  1           0
  router_solicitations    3           -1
  regen_max_retry         5           3

Each one went stale when the code changed and the documentation was not
updated, or was wrong from the start:

- cipso_v4_rbm_strictvalid has been initialised to 1 since CIPSO was
  merged, while the documentation added with it said 0.
- Commit be26849bfb6f ("ipv6: Disable flowlabel state ranges by
  default") changed the default of flowlabel_state_ranges to 0.
- Commit bd11f0741fa5 ("ipv6 addrconf: implement RFC7559 router
  solicitation backoff") changed MAX_RTR_SOLICITATIONS from 3 to -1,
  meaning that router solicitations are sent without a limit. The
  documentation was not updated and never mentioned -1.
- Commit 76f793e3a471 ("ipv6: updates to privacy addresses per RFC
  4941.") changed REGEN_MAX_RETRY from 5 to 3.

Update the four defaults and note that -1 means no limit for
router_solicitations.

The mismatches were found with the help of an AI assistant (Claude),
which compared the defaults documented in ip-sysctl.rst with the values
under /proc/sys/net on a running kernel and with the initial values in
the source. I confirmed each value with sysctl on a running kernel and
against the net-next source and the commits below. The commit message
was drafted with the same assistance.

Tested by building the networking documentation with
"make SPHINXDIRS=networking htmldocs": the change adds no warnings and
the four defaults render as updated.

Fixes: 8802f616f6de ("[NetLabel]: documentation")
Fixes: be26849bfb6f ("ipv6: Disable flowlabel state ranges by default")
Fixes: bd11f0741fa5 ("ipv6 addrconf: implement RFC7559 router solicitation backoff")
Fixes: 76f793e3a471 ("ipv6: updates to privacy addresses per RFC 4941.")
Signed-off-by: Gopal Malaviya <gopalmalaviya53@gmail.com>
---
 Documentation/networking/ip-sysctl.rst | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index bc22400b53..0b7bfbd98a 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -1587,7 +1587,7 @@ cipso_rbm_strictvalid - BOOLEAN
 	- 0 (disabled)
 	- 1 (enabled)
 
-	Default: 0 (disabled)
+	Default: 1 (enabled)
 
 IP Variables
 ============
@@ -2418,7 +2418,7 @@ flowlabel_state_ranges - BOOLEAN
 	- 0 (disabled)
 	- 1 (enabled)
 
-	Default: 1 (enabled)
+	Default: 0 (disabled)
 
 
 flowlabel_reflect - INTEGER
@@ -2956,9 +2956,9 @@ router_solicitation_interval - INTEGER
 
 router_solicitations - INTEGER
 	Number of Router Solicitations to send until assuming no
-	routers are present.
+	routers are present. A value of -1 means no limit.
 
-	Default: 3
+	Default: -1
 
 use_oif_addrs_only - BOOLEAN
 	When enabled, the candidate source addresses for destinations
@@ -3034,7 +3034,7 @@ regen_max_retry - INTEGER
 	Number of attempts before give up attempting to generate
 	valid temporary addresses.
 
-	Default: 5
+	Default: 3
 
 max_addresses - INTEGER
 	Maximum number of autoconfigured addresses per interface.  Setting

base-commit: fa5196392691051963726787944db872420dfa75
-- 
2.43.0