sctp: Add LSM hooks

Add security hooks allowing security modules to exercise access control
over SCTP.

Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index ead5fce..7a23896 100644 (file)
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1318,6 +1318,16 @@ struct sctp_endpoint {
              reconf_enable:1;
 
        __u8  strreset_enable;
+
+       /* Security identifiers from incoming (INIT). These are set by
+        * security_sctp_assoc_request(). These will only be used by
+        * SCTP TCP type sockets and peeled off connections as they
+        * cause a new socket to be generated. security_sctp_sk_clone()
+        * will then plug these into the new socket.
+        */
+
+       u32 secid;
+       u32 peer_secid;
 };
 
 /* Recover the outter endpoint structure. */

diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
index 4c4db14..64736ed 100644 (file)
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h
@@ -126,6 +126,7 @@ typedef __s32 sctp_assoc_t;
 #define SCTP_STREAM_SCHEDULER  123
 #define SCTP_STREAM_SCHEDULER_VALUE    124
 #define SCTP_INTERLEAVING_SUPPORTED    125
+#define SCTP_SENDMSG_CONNECT   126
 
 /* PR-SCTP policies */
 #define SCTP_PR_SCTP_NONE      0x0000

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index d01475f..70274ae 100644 (file)
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -3071,6 +3071,12 @@ static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
                if (af->is_any(&addr))
                        memcpy(&addr, &asconf->source, sizeof(addr));
 
+               if (security_sctp_bind_connect(asoc->ep->base.sk,
+                                              SCTP_PARAM_ADD_IP,
+                                              (struct sockaddr *)&addr,
+                                              af->sockaddr_len))
+                       return SCTP_ERROR_REQ_REFUSED;
+
                /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
                 * request and does not have the local resources to add this
                 * new address to the association, it MUST return an Error
@@ -3137,6 +3143,12 @@ static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
                if (af->is_any(&addr))
                        memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
 
+               if (security_sctp_bind_connect(asoc->ep->base.sk,
+                                              SCTP_PARAM_SET_PRIMARY,
+                                              (struct sockaddr *)&addr,
+                                              af->sockaddr_len))
+                       return SCTP_ERROR_REQ_REFUSED;
+
                peer = sctp_assoc_lookup_paddr(asoc, &addr);
                if (!peer)
                        return SCTP_ERROR_DNS_FAILED;

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index eb7905f..42659ab 100644 (file)
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -321,6 +321,11 @@ enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net,
        struct sctp_packet *packet;
        int len;
 
+       /* Update socket peer label if first association. */
+       if (security_sctp_assoc_request((struct sctp_endpoint *)ep,
+                                       chunk->skb))
+               return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
        /* 6.10 Bundling
         * An endpoint MUST NOT bundle INIT, INIT ACK or
         * SHUTDOWN COMPLETE with any other chunks.
@@ -908,6 +913,9 @@ enum sctp_disposition sctp_sf_do_5_1E_ca(struct net *net,
         */
        sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
 
+       /* Set peer label for connection. */
+       security_inet_conn_established(ep->base.sk, chunk->skb);
+
        /* RFC 2960 5.1 Normal Establishment of an Association
         *
         * E) Upon reception of the COOKIE ACK, endpoint "A" will move
@@ -1436,6 +1444,11 @@ static enum sctp_disposition sctp_sf_do_unexpected_init(
        struct sctp_packet *packet;
        int len;
 
+       /* Update socket peer label if first association. */
+       if (security_sctp_assoc_request((struct sctp_endpoint *)ep,
+                                       chunk->skb))
+               return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
        /* 6.10 Bundling
         * An endpoint MUST NOT bundle INIT, INIT ACK or
         * SHUTDOWN COMPLETE with any other chunks.
@@ -2106,6 +2119,11 @@ enum sctp_disposition sctp_sf_do_5_2_4_dupcook(
                }
        }
 
+       /* Update socket peer label if first association. */
+       if (security_sctp_assoc_request((struct sctp_endpoint *)ep,
+                                       chunk->skb))
+               return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
        /* Set temp so that it won't be added into hashtable */
        new_asoc->temp = 1;
 

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index eb55c63..73b34a6 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1043,6 +1043,12 @@ static int sctp_setsockopt_bindx(struct sock *sk,
        /* Do the work. */
        switch (op) {
        case SCTP_BINDX_ADD_ADDR:
+               /* Allow security module to validate bindx addresses. */
+               err = security_sctp_bind_connect(sk, SCTP_SOCKOPT_BINDX_ADD,
+                                                (struct sockaddr *)kaddrs,
+                                                addrs_size);
+               if (err)
+                       goto out;
                err = sctp_bindx_add(sk, kaddrs, addrcnt);
                if (err)
                        goto out;
@@ -1252,6 +1258,7 @@ static int __sctp_connect(struct sock *sk,
 
        if (assoc_id)
                *assoc_id = asoc->assoc_id;
+
        err = sctp_wait_for_connect(asoc, &timeo);
        /* Note: the asoc may be freed after the return of
         * sctp_wait_for_connect.
@@ -1347,7 +1354,16 @@ static int __sctp_setsockopt_connectx(struct sock *sk,
        if (unlikely(IS_ERR(kaddrs)))
                return PTR_ERR(kaddrs);
 
+       /* Allow security module to validate connectx addresses. */
+       err = security_sctp_bind_connect(sk, SCTP_SOCKOPT_CONNECTX,
+                                        (struct sockaddr *)kaddrs,
+                                         addrs_size);
+       if (err)
+               goto out_free;
+
        err = __sctp_connect(sk, kaddrs, addrs_size, assoc_id);
+
+out_free:
        kvfree(kaddrs);
 
        return err;
@@ -1615,6 +1631,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
        struct sctp_transport *transport, *chunk_tp;
        struct sctp_chunk *chunk;
        union sctp_addr to;
+       struct sctp_af *af;
        struct sockaddr *msg_name = NULL;
        struct sctp_sndrcvinfo default_sinfo;
        struct sctp_sndrcvinfo *sinfo;
@@ -1844,6 +1861,24 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
                }
 
                scope = sctp_scope(&to);
+
+               /* Label connection socket for first association 1-to-many
+                * style for client sequence socket()->sendmsg(). This
+                * needs to be done before sctp_assoc_add_peer() as that will
+                * set up the initial packet that needs to account for any
+                * security ip options (CIPSO/CALIPSO) added to the packet.
+                */
+               af = sctp_get_af_specific(to.sa.sa_family);
+               if (!af) {
+                       err = -EINVAL;
+                       goto out_unlock;
+               }
+               err = security_sctp_bind_connect(sk, SCTP_SENDMSG_CONNECT,
+                                                (struct sockaddr *)&to,
+                                                af->sockaddr_len);
+               if (err < 0)
+                       goto out_unlock;
+
                new_asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL);
                if (!new_asoc) {
                        err = -ENOMEM;
@@ -2909,6 +2944,8 @@ static int sctp_setsockopt_primary_addr(struct sock *sk, char __user *optval,
 {
        struct sctp_prim prim;
        struct sctp_transport *trans;
+       struct sctp_af *af;
+       int err;
 
        if (optlen != sizeof(struct sctp_prim))
                return -EINVAL;
@@ -2916,6 +2953,17 @@ static int sctp_setsockopt_primary_addr(struct sock *sk, char __user *optval,
        if (copy_from_user(&prim, optval, sizeof(struct sctp_prim)))
                return -EFAULT;
 
+       /* Allow security module to validate address but need address len. */
+       af = sctp_get_af_specific(prim.ssp_addr.ss_family);
+       if (!af)
+               return -EINVAL;
+
+       err = security_sctp_bind_connect(sk, SCTP_PRIMARY_ADDR,
+                                        (struct sockaddr *)&prim.ssp_addr,
+                                        af->sockaddr_len);
+       if (err)
+               return err;
+
        trans = sctp_addr_id2transport(sk, &prim.ssp_addr, prim.ssp_assoc_id);
        if (!trans)
                return -EINVAL;
@@ -3247,6 +3295,13 @@ static int sctp_setsockopt_peer_primary_addr(struct sock *sk, char __user *optva
        if (!sctp_assoc_lookup_laddr(asoc, (union sctp_addr *)&prim.sspp_addr))
                return -EADDRNOTAVAIL;
 
+       /* Allow security module to validate address. */
+       err = security_sctp_bind_connect(sk, SCTP_SET_PEER_PRIMARY_ADDR,
+                                        (struct sockaddr *)&prim.sspp_addr,
+                                        af->sockaddr_len);
+       if (err)
+               return err;
+
        /* Create an ASCONF chunk with SET_PRIMARY parameter    */
        chunk = sctp_make_asconf_set_prim(asoc,
                                          (union sctp_addr *)&prim.sspp_addr);
@@ -8346,6 +8401,8 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk,
 {
        struct inet_sock *inet = inet_sk(sk);
        struct inet_sock *newinet;
+       struct sctp_sock *sp = sctp_sk(sk);
+       struct sctp_endpoint *ep = sp->ep;
 
        newsk->sk_type = sk->sk_type;
        newsk->sk_bound_dev_if = sk->sk_bound_dev_if;
@@ -8388,7 +8445,10 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk,
        if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
                net_enable_timestamp();
 
-       security_sk_clone(sk, newsk);
+       /* Set newsk security attributes from orginal sk and connection
+        * security attribute from ep.
+        */
+       security_sctp_sk_clone(ep, sk, newsk);
 }
 
 static inline void sctp_copy_descendant(struct sock *sk_to,