From d62c612ef8a66be534a3ada598cfa28d40cd0b3c Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Mon, 19 May 2008 13:45:33 -0700 Subject: [PATCH] netns: Introduce sysctl root for read-only net sysctls. This one stores all ctl-heads in one list and restricts the permissions not give write access to non-init net namespaces. Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller --- include/net/net_namespace.h | 3 +++ net/sysctl_net.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 33 insertions(+) diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index aa540e6be50..8df751b3be5 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -201,8 +201,11 @@ extern void unregister_pernet_gen_device(int id, struct pernet_operations *); struct ctl_path; struct ctl_table; struct ctl_table_header; + extern struct ctl_table_header *register_net_sysctl_table(struct net *net, const struct ctl_path *path, struct ctl_table *table); +extern struct ctl_table_header *register_net_sysctl_rotable( + const struct ctl_path *path, struct ctl_table *table); extern void unregister_net_sysctl_table(struct ctl_table_header *header); #endif /* __NET_NET_NAMESPACE_H */ diff --git a/net/sysctl_net.c b/net/sysctl_net.c index b4f0525f91a..d8e79162724 100644 --- a/net/sysctl_net.c +++ b/net/sysctl_net.c @@ -40,6 +40,27 @@ static struct ctl_table_root net_sysctl_root = { .lookup = net_ctl_header_lookup, }; +static LIST_HEAD(net_sysctl_ro_tables); +static struct list_head *net_ctl_ro_header_lookup(struct ctl_table_root *root, + struct nsproxy *namespaces) +{ + return &net_sysctl_ro_tables; +} + +static int net_ctl_ro_header_perms(struct ctl_table_root *root, + struct nsproxy *namespaces, struct ctl_table *table) +{ + if (namespaces->net_ns == &init_net) + return table->mode; + else + return table->mode & ~0222; +} + +static struct ctl_table_root net_sysctl_ro_root = { + .lookup = net_ctl_ro_header_lookup, + .permissions = net_ctl_ro_header_perms, +}; + static int sysctl_net_init(struct net *net) { INIT_LIST_HEAD(&net->sysctl_table_headers); @@ -64,6 +85,7 @@ static __init int sysctl_init(void) if (ret) goto out; register_sysctl_root(&net_sysctl_root); + register_sysctl_root(&net_sysctl_ro_root); out: return ret; } @@ -80,6 +102,14 @@ struct ctl_table_header *register_net_sysctl_table(struct net *net, } EXPORT_SYMBOL_GPL(register_net_sysctl_table); +struct ctl_table_header *register_net_sysctl_rotable(const + struct ctl_path *path, struct ctl_table *table) +{ + return __register_sysctl_paths(&net_sysctl_ro_root, + &init_nsproxy, path, table); +} +EXPORT_SYMBOL_GPL(register_net_sysctl_rotable); + void unregister_net_sysctl_table(struct ctl_table_header *header) { unregister_sysctl_table(header); -- 2.41.1