ieee802154: add dgram sockopts for security control

Allow datagram sockets to override the security settings of the device
they send from on a per-socket basis. Requires CAP_NET_ADMIN or
CAP_NET_RAW, since raw sockets can send arbitrary packets anyway.

Signed-off-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 66 insertions, 0 deletions

diff --git a/net/ieee802154/dgram.c b/net/ieee802154/dgram.c
index 76c77256a56e..4f0ed8780194 100644
--- a/net/ieee802154/dgram.c
+++ b/net/ieee802154/dgram.c
@@ -21,6 +21,7 @@
  * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
  */
 
+#include <linux/capability.h>
 #include <linux/net.h>
 #include <linux/module.h>
 #include <linux/if_arp.h>
@@ -47,6 +48,10 @@ struct dgram_sock {
         unsigned int bound:1;
         unsigned int connected:1;
         unsigned int want_ack:1;
+        unsigned int secen:1;
+        unsigned int secen_override:1;
+        unsigned int seclevel:3;
+        unsigned int seclevel_override:1;
 };
 
 static inline struct dgram_sock *dgram_sk(const struct sock *sk)
@@ -264,6 +269,11 @@ static int dgram_sendmsg(struct kiocb *iocb, struct sock *sk,
                 dst_addr = ro->dst_addr;
         }
 
+        cb->secen = ro->secen;
+        cb->secen_override = ro->secen_override;
+        cb->seclevel = ro->seclevel;
+        cb->seclevel_override = ro->seclevel_override;
+
         err = dev_hard_header(skb, dev, ETH_P_IEEE802154, &dst_addr,
                               ro->bound ? &ro->src_addr : NULL, size);
         if (err < 0)
@@ -427,6 +437,20 @@ static int dgram_getsockopt(struct sock *sk, int level, int optname,
         case WPAN_WANTACK:
                 val = ro->want_ack;
                 break;
+        case WPAN_SECURITY:
+                if (!ro->secen_override)
+                        val = WPAN_SECURITY_DEFAULT;
+                else if (ro->secen)
+                        val = WPAN_SECURITY_ON;
+                else
+                        val = WPAN_SECURITY_OFF;
+                break;
+        case WPAN_SECURITY_LEVEL:
+                if (!ro->seclevel_override)
+                        val = WPAN_SECURITY_LEVEL_DEFAULT;
+                else
+                        val = ro->seclevel;
+                break;
         default:
                 return -ENOPROTOOPT;
         }
@@ -442,6 +466,7 @@ static int dgram_setsockopt(struct sock *sk, int level, int optname,
                     char __user *optval, unsigned int optlen)
 {
         struct dgram_sock *ro = dgram_sk(sk);
+        struct net *net = sock_net(sk);
         int val;
         int err = 0;
 
@@ -457,6 +482,47 @@ static int dgram_setsockopt(struct sock *sk, int level, int optname,
         case WPAN_WANTACK:
                 ro->want_ack = !!val;
                 break;
+        case WPAN_SECURITY:
+                if (!ns_capable(net->user_ns, CAP_NET_ADMIN) &&
+                    !ns_capable(net->user_ns, CAP_NET_RAW)) {
+                        err = -EPERM;
+                        break;
+                }
+
+                switch (val) {
+                case WPAN_SECURITY_DEFAULT:
+                        ro->secen_override = 0;
+                        break;
+                case WPAN_SECURITY_ON:
+                        ro->secen_override = 1;
+                        ro->secen = 1;
+                        break;
+                case WPAN_SECURITY_OFF:
+                        ro->secen_override = 1;
+                        ro->secen = 0;
+                        break;
+                default:
+                        err = -EINVAL;
+                        break;
+                }
+                break;
+        case WPAN_SECURITY_LEVEL:
+                if (!ns_capable(net->user_ns, CAP_NET_ADMIN) &&
+                    !ns_capable(net->user_ns, CAP_NET_RAW)) {
+                        err = -EPERM;
+                        break;
+                }
+
+                if (val < WPAN_SECURITY_LEVEL_DEFAULT ||
+                    val > IEEE802154_SCF_SECLEVEL_ENC_MIC128) {
+                        err = -EINVAL;
+                } else if (val == WPAN_SECURITY_LEVEL_DEFAULT) {
+                        ro->seclevel_override = 0;
+                } else {
+                        ro->seclevel_override = 1;
+                        ro->seclevel = val;
+                }
+                break;
         default:
                 err = -ENOPROTOOPT;
                 break;