From 024626e36d75fc8c6e32d50d4c68bfc3b8df5fdf Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Sat, 8 Dec 2007 00:09:24 -0800 Subject: [PATCH] [NET] sysctl: make the sys.net.core sysctls per-namespace Making them per-namespace is required for the following two reasons: First, some ctl values have a per-namespace meaning. Second, making them writable from the sub-namespace is an isolation hole. So I introduce the pernet operations to create these tables. For init_net I use the existing statically declared tables, for sub-namespace they are duplicated and the write bits are removed from the mode. Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller --- include/net/net_namespace.h | 3 +++ net/core/sysctl_net_core.c | 50 +++++++++++++++++++++++++++++++++---- 2 files changed, 48 insertions(+), 5 deletions(-) diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index f97b2a4469ae..d5936115d972 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -37,6 +37,9 @@ struct net { struct sock *rtnl; /* rtnetlink socket */ + /* core sysctls */ + struct ctl_table_header *sysctl_core_hdr; + /* List of all packet sockets. */ rwlock_t packet_sklist_lock; struct hlist_head packet_sklist; diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index e322713e590a..57a7eadb8551 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -151,18 +151,58 @@ static struct ctl_table net_core_table[] = { { .ctl_name = 0 } }; -static __initdata struct ctl_path net_core_path[] = { +static __net_initdata struct ctl_path net_core_path[] = { { .procname = "net", .ctl_name = CTL_NET, }, { .procname = "core", .ctl_name = NET_CORE, }, { }, }; -static __init int sysctl_core_init(void) +static __net_init int sysctl_core_net_init(struct net *net) { - struct ctl_table_header *hdr; + struct ctl_table *tbl, *tmp; + + tbl = net_core_table; + if (net != &init_net) { + tbl = kmemdup(tbl, sizeof(net_core_table), GFP_KERNEL); + if (tbl == NULL) + goto err_dup; + + for (tmp = tbl; tmp->procname; tmp++) + tmp->mode &= ~0222; + } + + net->sysctl_core_hdr = register_net_sysctl_table(net, + net_core_path, tbl); + if (net->sysctl_core_hdr == NULL) + goto err_reg; - hdr = register_sysctl_paths(net_core_path, net_core_table); - return hdr == NULL ? -ENOMEM : 0; + return 0; + +err_reg: + if (tbl != net_core_table) + kfree(tbl); +err_dup: + return -ENOMEM; +} + +static __net_exit void sysctl_core_net_exit(struct net *net) +{ + struct ctl_table *tbl; + + tbl = net->sysctl_core_hdr->ctl_table_arg; + unregister_net_sysctl_table(net->sysctl_core_hdr); + BUG_ON(tbl == net_core_table); + kfree(tbl); +} + +static __net_initdata struct pernet_operations sysctl_core_ops = { + .init = sysctl_core_net_init, + .exit = sysctl_core_net_exit, +}; + +static __init int sysctl_core_init(void) +{ + return register_pernet_subsys(&sysctl_core_ops); } __initcall(sysctl_core_init); -- 2.20.1