net: Push capable(CAP_NET_ADMIN) into the rtnl methods

- In rtnetlink_rcv_msg convert the capable(CAP_NET_ADMIN) check
  to ns_capable(net->user-ns, CAP_NET_ADMIN).  Allowing unprivileged
  users to make netlink calls to modify their local network
  namespace.

- In the rtnetlink doit methods add capable(CAP_NET_ADMIN) so
  that calls that are not safe for unprivileged users are still
  protected.

Later patches will remove the extra capable calls from methods
that are safe for unprivilged users.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_netlink.c

@@ -240,6 +240,9 @@ int br_setlink(struct net_device *dev, struct nlmsghdr *nlh)
 	struct nlattr *tb[IFLA_BRPORT_MAX];
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	ifm = nlmsg_data(nlh);
 
 	protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO);

net/can/gw.c

@@ -751,6 +751,9 @@ static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh,
 	struct cgw_job *gwj;
 	int err = 0;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (nlmsg_len(nlh) < sizeof(*r))
 		return -EINVAL;
 
@@ -839,6 +842,9 @@ static int cgw_remove_job(struct sk_buff *skb,  struct nlmsghdr *nlh, void *arg)
 	struct can_can_gw ccgw;
 	int err = 0;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (nlmsg_len(nlh) < sizeof(*r))
 		return -EINVAL;
 

net/core/fib_rules.c

@@ -275,6 +275,9 @@ static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 	struct nlattr *tb[FRA_MAX+1];
 	int err = -EINVAL, unresolved = 0;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 		goto errout;
 
@@ -424,6 +427,9 @@ static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 	struct nlattr *tb[FRA_MAX+1];
 	int err = -EINVAL;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 		goto errout;
 

net/core/neighbour.c

@@ -1620,6 +1620,9 @@ static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	struct net_device *dev = NULL;
 	int err = -EINVAL;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	ASSERT_RTNL();
 	if (nlmsg_len(nlh) < sizeof(*ndm))
 		goto out;
@@ -1684,6 +1687,9 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	struct net_device *dev = NULL;
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	ASSERT_RTNL();
 	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
 	if (err < 0)
@@ -1962,6 +1968,9 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	struct nlattr *tb[NDTA_MAX+1];
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	err = nlmsg_parse(nlh, sizeof(*ndtmsg), tb, NDTA_MAX,
 			  nl_neightbl_policy);
 	if (err < 0)

net/core/rtnetlink.c

@@ -1547,6 +1547,9 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	struct nlattr *tb[IFLA_MAX+1];
 	char ifname[IFNAMSIZ];
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
 	if (err < 0)
 		goto errout;
@@ -1590,6 +1593,9 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	int err;
 	LIST_HEAD(list_kill);
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
 	if (err < 0)
 		return err;
@@ -1720,6 +1726,9 @@ static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	struct nlattr *linkinfo[IFLA_INFO_MAX+1];
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 #ifdef CONFIG_MODULES
 replay:
 #endif
@@ -2057,6 +2066,9 @@ static int rtnl_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	u8 *addr;
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
 	if (err < 0)
 		return err;
@@ -2123,6 +2135,9 @@ static int rtnl_fdb_del(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	int err = -EINVAL;
 	__u8 *addr;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (nlmsg_len(nlh) < sizeof(*ndm))
 		return -EINVAL;
 
@@ -2488,7 +2503,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	sz_idx = type>>2;
 	kind = type&3;
 
-	if (kind != 2 && !capable(CAP_NET_ADMIN))
+	if (kind != 2 && !ns_capable(net->user_ns, CAP_NET_ADMIN))
 		return -EPERM;
 
 	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {

net/dcb/dcbnl.c

@@ -1662,6 +1662,9 @@ static int dcb_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	struct nlmsghdr *reply_nlh = NULL;
 	const struct reply_func *fn;
 
+	if ((nlh->nlmsg_type == RTM_SETDCB) && !capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (!net_eq(net, &init_net))
 		return -EINVAL;
 

net/decnet/dn_dev.c

@@ -573,6 +573,9 @@ static int dn_nl_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	struct dn_ifaddr __rcu **ifap;
 	int err = -EINVAL;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (!net_eq(net, &init_net))
 		goto errout;
 
@@ -614,6 +617,9 @@ static int dn_nl_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	struct dn_ifaddr *ifa;
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (!net_eq(net, &init_net))
 		return -EINVAL;
 

net/decnet/dn_fib.c

@@ -520,6 +520,9 @@ static int dn_fib_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *
 	struct rtattr **rta = arg;
 	struct rtmsg *r = NLMSG_DATA(nlh);
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (!net_eq(net, &init_net))
 		return -EINVAL;
 
@@ -540,6 +543,9 @@ static int dn_fib_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *
 	struct rtattr **rta = arg;
 	struct rtmsg *r = NLMSG_DATA(nlh);
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (!net_eq(net, &init_net))
 		return -EINVAL;
 

net/ipv4/devinet.c

@@ -539,6 +539,9 @@ static int inet_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg
 
 	ASSERT_RTNL();
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv4_policy);
 	if (err < 0)
 		goto errout;
@@ -646,6 +649,9 @@ static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg
 
 	ASSERT_RTNL();
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	ifa = rtm_to_ifaddr(net, nlh);
 	if (IS_ERR(ifa))
 		return PTR_ERR(ifa);

net/ipv4/fib_frontend.c

@@ -613,6 +613,9 @@ static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *ar
 	struct fib_table *tb;
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	err = rtm_to_fib_config(net, skb, nlh, &cfg);
 	if (err < 0)
 		goto errout;
@@ -635,6 +638,9 @@ static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *ar
 	struct fib_table *tb;
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	err = rtm_to_fib_config(net, skb, nlh, &cfg);
 	if (err < 0)
 		goto errout;

net/ipv6/addrconf.c

@@ -3514,6 +3514,9 @@ inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	struct in6_addr *pfx;
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
 	if (err < 0)
 		return err;
@@ -3584,6 +3587,9 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	u8 ifa_flags;
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
 	if (err < 0)
 		return err;

net/ipv6/addrlabel.c

@@ -425,6 +425,9 @@ static int ip6addrlbl_newdel(struct sk_buff *skb, struct nlmsghdr *nlh,
 	u32 label;
 	int err = 0;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
 	if (err < 0)
 		return err;

net/ipv6/route.c

@@ -2446,6 +2446,9 @@ static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *a
 	struct fib6_config cfg;
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	err = rtm_to_fib6_config(skb, nlh, &cfg);
 	if (err < 0)
 		return err;
@@ -2461,6 +2464,9 @@ static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *a
 	struct fib6_config cfg;
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	err = rtm_to_fib6_config(skb, nlh, &cfg);
 	if (err < 0)
 		return err;

net/phonet/pn_netlink.c

@@ -70,6 +70,9 @@ static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *attr)
 	int err;
 	u8 pnaddr;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
@@ -230,6 +233,9 @@ static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *attr)
 	int err;
 	u8 dst;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 

net/sched/act_api.c

@@ -987,6 +987,9 @@ static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 	u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 	int ret = 0, ovr = 0;
 
+	if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 	if (ret < 0)
 		return ret;

net/sched/cls_api.c

@@ -139,6 +139,8 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 	int err;
 	int tp_created = 0;
 
+	if ((n->nlmsg_type != RTM_GETTFILTER) && !capable(CAP_NET_ADMIN))
+		return -EPERM;
 replay:
 	t = nlmsg_data(n);
 	protocol = TC_H_MIN(t->tcm_info);

net/sched/sch_api.c

@@ -980,6 +980,9 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 	struct Qdisc *p = NULL;
 	int err;
 
+	if ((n->nlmsg_type != RTM_GETQDISC) && !capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
 	if (!dev)
 		return -ENODEV;
@@ -1043,6 +1046,9 @@ static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 	struct Qdisc *q, *p;
 	int err;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 replay:
 	/* Reinit, just in case something touches this. */
 	tcm = nlmsg_data(n);
@@ -1379,6 +1385,9 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 	u32 qid = TC_H_MAJ(clid);
 	int err;
 
+	if ((n->nlmsg_type != RTM_GETTCLASS) && !capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
 	if (!dev)
 		return -ENODEV;