Date: Mon, 08 Dec 2025 16:15:25 +0000 From: Cy Schubert <cy@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: d9788eabffa4 - main - ipfilter: Restrict ipfilter within a jail Message-ID: <6936f99d.3ab3f.185d9547@gitrepo.freebsd.org>
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The branch main has been updated by cy: URL: https://cgit.FreeBSD.org/src/commit/?id=d9788eabffa4b67fc534685fc3d9b8e3334af196 commit d9788eabffa4b67fc534685fc3d9b8e3334af196 Author: Cy Schubert <cy@FreeBSD.org> AuthorDate: 2025-10-29 18:29:39 +0000 Commit: Cy Schubert <cy@FreeBSD.org> CommitDate: 2025-12-08 16:15:18 +0000 ipfilter: Restrict ipfilter within a jail Add a sysctl/tunable (net.inet.ipf.jail_allowed) to control whether a jail can manage its own ipfilter rules, pools, and settings. A jail's control over its own ipfilter rules and settings may not be desireable. The default is jail access to ipfilter is denied. The host system can stil manage a jail's rules by attaching the rules, using the on keyword, limiting the rule to the jail's interface. Or the sysctl/tunable can be enabled to allow a jail control over its own ipfilter rules and settings. Implementation note: Rather than store the jail_allowed variable, referenced by sysctl(9), in a global area, storing the variable in the ipfilter softc is consistent with ipfilter's use of its softc. Discussed with: emaste, jrm MFC after: 1 week Differential revision: https://reviews.freebsd.org/D53623 --- sbin/ipf/libipf/interror.c | 1 + sys/netpfil/ipfilter/netinet/fil.c | 1 + sys/netpfil/ipfilter/netinet/ip_fil.h | 1 + sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c | 15 +++++++++++++++ sys/netpfil/ipfilter/netinet/mlfk_ipl.c | 1 + 5 files changed, 19 insertions(+) diff --git a/sbin/ipf/libipf/interror.c b/sbin/ipf/libipf/interror.c index 6d5391f58ba2..2bbecaa154e6 100644 --- a/sbin/ipf/libipf/interror.c +++ b/sbin/ipf/libipf/interror.c @@ -531,6 +531,7 @@ log" }, { 130016, "finding pfil head failed" }, { 130017, "ipfilter is already initialised and running" }, { 130018, "ioctl denied in jail without VNET" }, + { 130019, "ioctl denied in jail" }, }; diff --git a/sys/netpfil/ipfilter/netinet/fil.c b/sys/netpfil/ipfilter/netinet/fil.c index 0c5e22517dc4..242affeff000 100644 --- a/sys/netpfil/ipfilter/netinet/fil.c +++ b/sys/netpfil/ipfilter/netinet/fil.c @@ -9096,6 +9096,7 @@ ipf_main_soft_create(void *arg) softc->ipf_icmpminfragmtu = 68; softc->ipf_max_namelen = 128; softc->ipf_flags = IPF_LOGGING; + softc->ipf_jail_allowed = 0; #ifdef LARGE_NAT softc->ipf_large_nat = 1; diff --git a/sys/netpfil/ipfilter/netinet/ip_fil.h b/sys/netpfil/ipfilter/netinet/ip_fil.h index 7b070f0d6867..24d4f9695322 100644 --- a/sys/netpfil/ipfilter/netinet/ip_fil.h +++ b/sys/netpfil/ipfilter/netinet/ip_fil.h @@ -1550,6 +1550,7 @@ typedef struct ipf_main_softc_s { u_int ipf_icmpacktimeout; u_int ipf_iptimeout; u_int ipf_large_nat; + u_int ipf_jail_allowed; u_long ipf_ticks; u_long ipf_userifqs; u_long ipf_rb_no_mem; diff --git a/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c b/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c index 6eb6cf2a7a47..43b590cc0204 100644 --- a/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c +++ b/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c @@ -88,6 +88,7 @@ VNET_DEFINE(ipf_main_softc_t, ipfmain) = { .ipf_running = -2, }; #define V_ipfmain VNET(ipfmain) +#define V0_ipfmain VNET_VNET(vnet0,ipfmain) #include <sys/conf.h> #include <net/pfil.h> @@ -254,6 +255,20 @@ ipfioctl(struct cdev *dev, ioctlcmd_t cmd, caddr_t data, return (EPERM); } + /* + * Remember, the host system (with its vnet0) controls + * whether a jail is allowed to use ipfilter or not. + * The default is ipfilter cannot be used by a jail + * unless the sysctl allows it. + */ + if (V0_ipfmain.ipf_jail_allowed == 0) { + if (jailed(p->p_cred)) { + V_ipfmain.ipf_interror = 130019; + CURVNET_RESTORE(); + return (EOPNOTSUPP); + } + } + if (jailed_without_vnet(p->p_cred)) { V_ipfmain.ipf_interror = 130018; CURVNET_RESTORE(); diff --git a/sys/netpfil/ipfilter/netinet/mlfk_ipl.c b/sys/netpfil/ipfilter/netinet/mlfk_ipl.c index d558b2d24b2c..139fe1f766d3 100644 --- a/sys/netpfil/ipfilter/netinet/mlfk_ipl.c +++ b/sys/netpfil/ipfilter/netinet/mlfk_ipl.c @@ -136,6 +136,7 @@ SYSCTL_IPF(_net_inet_ipf, OID_AUTO, fr_chksrc, CTLFLAG_RW, &VNET_NAME(ipfmain.ip SYSCTL_IPF(_net_inet_ipf, OID_AUTO, fr_minttl, CTLFLAG_RW, &VNET_NAME(ipfmain.ipf_minttl), 0, ""); SYSCTL_IPF(_net_inet_ipf, OID_AUTO, large_nat, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &VNET_NAME(ipfmain.ipf_large_nat), 0, "large_nat"); SYSCTL_IPF(_net_inet_ipf, OID_AUTO, fr_max_namelen, CTLFLAG_RWTUN, &VNET_NAME(ipfmain.ipf_max_namelen), 0, "max_namelen"); +SYSCTL_IPF(_net_inet_ipf, OID_AUTO, jail_allowed, CTLFLAG_RWTUN, &VNET_NAME(ipfmain.ipf_jail_allowed), 0, "jail_allowed"); #define CDEV_MAJOR 79 #include <sys/poll.h>
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