git: e75dda31c1ee - main - jaildesc: remove desc from the sysctl parameter list

[Jamie Gritton]

The branch main has been updated by jamie:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=e75dda31c1eead9ad40580bd8fec17f2bbf55a21

commit e75dda31c1eead9ad40580bd8fec17f2bbf55a21
Author:     Jamie Gritton <ja...@freebsd.org>
AuthorDate: 2025-09-13 22:30:14 +0000
Commit:     Jamie Gritton <ja...@freebsd.org>
CommitDate: 2025-09-13 22:30:14 +0000

    jaildesc: remove desc from the sysctl parameter list
    
    Like lastjid, desc should count as a pseudo-parameter.  The difference
    lies entirely in the security.jail.param sysctls, which list all of
    the jail parameters.  Since desc opens and returns a file descriptor,
    it has no place in such uses as "jls all."  Like lastjid, it's still
    recognized by the kernel if passed in/out, and hard-coded into libjail
    so it can be recognized there.
    
    MFC after:      3 days
---
 lib/libjail/jail.c   | 10 +++++++++-
 sys/kern/kern_jail.c |  1 -
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/libjail/jail.c b/lib/libjail/jail.c
index f761bc6993e5..ad3348af0d2d 100644
--- a/lib/libjail/jail.c
+++ b/lib/libjail/jail.c
@@ -920,13 +920,21 @@ jailparam_type(struct jailparam *jp)
        } desc;
        int mib[CTL_MAXNAME];
 
-       /* The "lastjid" parameter isn't real. */
+       /*
+        * Some pseudo-parameters don't show up in the sysctl
+        * parameter list.
+        */
        name = jp->jp_name;
        if (!strcmp(name, "lastjid")) {
                jp->jp_valuelen = sizeof(int);
                jp->jp_ctltype = CTLTYPE_INT | CTLFLAG_WR;
                return (0);
        }
+       if (!strcmp(name, "desc")) {
+               jp->jp_valuelen = sizeof(int);
+               jp->jp_ctltype = CTLTYPE_INT | CTLFLAG_RW;
+               return (0);
+       }
 
        /* Find the sysctl that describes the parameter. */
        mib[0] = 0;
diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c
index 43035dc009b3..a75ba89d2a7e 100644
--- a/sys/kern/kern_jail.c
+++ b/sys/kern/kern_jail.c
@@ -4935,7 +4935,6 @@ sysctl_jail_param(SYSCTL_HANDLER_ARGS)
  * jail creation time but cannot be changed in an existing jail.
  */
 SYSCTL_JAIL_PARAM(, jid, CTLTYPE_INT | CTLFLAG_RDTUN, "I", "Jail ID");
-SYSCTL_JAIL_PARAM(, desc, CTLTYPE_INT | CTLFLAG_RW, "I", "Jail descriptor");
 SYSCTL_JAIL_PARAM(, parent, CTLTYPE_INT | CTLFLAG_RD, "I", "Jail parent ID");
 SYSCTL_JAIL_PARAM_STRING(, name, CTLFLAG_RW, MAXHOSTNAMELEN, "Jail name");
 SYSCTL_JAIL_PARAM_STRING(, path, CTLFLAG_RDTUN, MAXPATHLEN, "Jail root path");