[NETFILTER] nfnetlink: unconditionally require CAP_NET_ADMIN

This patch unconditionally requires CAP_NET_ADMIN for all nfnetlink
messages.  It also removes the per-message cap_required field, since all
existing subsystems use CAP_NET_ADMIN for all their messages anyway.

Patrick McHardy owes me a beer if we ever need to re-introduce this.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h
index 8be2f84..934a247 100644 (file)
--- a/include/linux/netfilter/nfnetlink.h
+++ b/include/linux/netfilter/nfnetlink.h
@@ -112,7 +112,6 @@ struct nfnl_callback
 {
        int (*call)(struct sock *nl, struct sk_buff *skb, 
                struct nlmsghdr *nlh, struct nfattr *cda[], int *errp);
-       kernel_cap_t cap_required; /* capabilities required for this msg */
        u_int16_t attr_count;   /* number of nfattr's */
 };
 

diff --git a/net/ipv4/netfilter/ip_conntrack_netlink.c b/net/ipv4/netfilter/ip_conntrack_netlink.c
index f5e5e31..de9f446 100644 (file)
--- a/net/ipv4/netfilter/ip_conntrack_netlink.c
+++ b/net/ipv4/netfilter/ip_conntrack_netlink.c
@@ -1543,29 +1543,22 @@ static struct notifier_block ctnl_notifier_exp = {
 
 static struct nfnl_callback ctnl_cb[IPCTNL_MSG_MAX] = {
        [IPCTNL_MSG_CT_NEW]             = { .call = ctnetlink_new_conntrack,
-                                           .attr_count = CTA_MAX,
-                                           .cap_required = CAP_NET_ADMIN },
+                                           .attr_count = CTA_MAX, },
        [IPCTNL_MSG_CT_GET]             = { .call = ctnetlink_get_conntrack,
-                                           .attr_count = CTA_MAX,
-                                           .cap_required = CAP_NET_ADMIN },
+                                           .attr_count = CTA_MAX, },
        [IPCTNL_MSG_CT_DELETE]          = { .call = ctnetlink_del_conntrack,
-                                           .attr_count = CTA_MAX,
-                                           .cap_required = CAP_NET_ADMIN },
+                                           .attr_count = CTA_MAX, },
        [IPCTNL_MSG_CT_GET_CTRZERO]     = { .call = ctnetlink_get_conntrack,
-                                           .attr_count = CTA_MAX,
-                                           .cap_required = CAP_NET_ADMIN },
+                                           .attr_count = CTA_MAX, },
 };
 
 static struct nfnl_callback ctnl_exp_cb[IPCTNL_MSG_EXP_MAX] = {
        [IPCTNL_MSG_EXP_GET]            = { .call = ctnetlink_get_expect,
-                                           .attr_count = CTA_EXPECT_MAX,
-                                           .cap_required = CAP_NET_ADMIN },
+                                           .attr_count = CTA_EXPECT_MAX, },
        [IPCTNL_MSG_EXP_NEW]            = { .call = ctnetlink_new_expect,
-                                           .attr_count = CTA_EXPECT_MAX,
-                                           .cap_required = CAP_NET_ADMIN },
+                                           .attr_count = CTA_EXPECT_MAX, },
        [IPCTNL_MSG_EXP_DELETE]         = { .call = ctnetlink_del_expect,
-                                           .attr_count = CTA_EXPECT_MAX,
-                                           .cap_required = CAP_NET_ADMIN },
+                                           .attr_count = CTA_EXPECT_MAX, },
 };
 
 static struct nfnetlink_subsystem ctnl_subsys = {

diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index 83f4c53..a60c59b 100644 (file)
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -223,6 +223,12 @@ static inline int nfnetlink_rcv_msg(struct sk_buff *skb,
                 NFNL_SUBSYS_ID(nlh->nlmsg_type),
                 NFNL_MSG_TYPE(nlh->nlmsg_type));
 
+       if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN)) {
+               DEBUGP("missing CAP_NET_ADMIN\n");
+               *errp = -EPERM;
+               return -1;
+       }
+
        /* Only requests are handled by kernel now. */
        if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) {
                DEBUGP("received non-request message\n");
@@ -240,15 +246,12 @@ static inline int nfnetlink_rcv_msg(struct sk_buff *skb,
        ss = nfnetlink_get_subsys(type);
        if (!ss) {
 #ifdef CONFIG_KMOD
-               if (cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN)) {
-                       /* don't call nfnl_shunlock, since it would reenter
-                        * with further packet processing */
-                       up(&nfnl_sem);
-                       request_module("nfnetlink-subsys-%d",
-                                       NFNL_SUBSYS_ID(type));
-                       nfnl_shlock();
-                       ss = nfnetlink_get_subsys(type);
-               }
+               /* don't call nfnl_shunlock, since it would reenter
+                * with further packet processing */
+               up(&nfnl_sem);
+               request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type));
+               nfnl_shlock();
+               ss = nfnetlink_get_subsys(type);
                if (!ss)
 #endif
                        goto err_inval;
@@ -260,13 +263,6 @@ static inline int nfnetlink_rcv_msg(struct sk_buff *skb,
                goto err_inval;
        }
 
-       if (nc->cap_required && 
-           !cap_raised(NETLINK_CB(skb).eff_cap, nc->cap_required)) {
-               DEBUGP("permission denied for type %d\n", type);
-               *errp = -EPERM;
-               return -1;
-       }
-
        {
                u_int16_t attr_count = 
                        ss->cb[NFNL_MSG_TYPE(nlh->nlmsg_type)].attr_count;

diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index d194676..cba6372 100644 (file)
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -862,11 +862,9 @@ out_put:
 
 static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
        [NFULNL_MSG_PACKET]     = { .call = nfulnl_recv_unsupp,
-                                   .attr_count = NFULA_MAX,
-                                   .cap_required = CAP_NET_ADMIN, },
+                                   .attr_count = NFULA_MAX, },
        [NFULNL_MSG_CONFIG]     = { .call = nfulnl_recv_config,
-                                   .attr_count = NFULA_CFG_MAX,
-                                   .cap_required = CAP_NET_ADMIN },
+                                   .attr_count = NFULA_CFG_MAX, },
 };
 
 static struct nfnetlink_subsystem nfulnl_subsys = {

diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index f065a6c..f28460b 100644 (file)
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -931,14 +931,11 @@ out_put:
 
 static struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
        [NFQNL_MSG_PACKET]      = { .call = nfqnl_recv_unsupp,
-                                   .attr_count = NFQA_MAX,
-                                   .cap_required = CAP_NET_ADMIN },
+                                   .attr_count = NFQA_MAX, },
        [NFQNL_MSG_VERDICT]     = { .call = nfqnl_recv_verdict,
-                                   .attr_count = NFQA_MAX,
-                                   .cap_required = CAP_NET_ADMIN },
+                                   .attr_count = NFQA_MAX, },
        [NFQNL_MSG_CONFIG]      = { .call = nfqnl_recv_config,
-                                   .attr_count = NFQA_CFG_MAX,
-                                   .cap_required = CAP_NET_ADMIN },
+                                   .attr_count = NFQA_CFG_MAX, },
 };
 
 static struct nfnetlink_subsystem nfqnl_subsys = {