PATCH V5 4/4] selinux: Add SCTP support
Neil Horman
nhorman at tuxdriver.com
Fri Jan 12 14:59:17 UTC 2018
On Thu, Jan 11, 2018 at 11:31:06AM +0000, Richard Haines wrote:
> The SELinux SCTP implementation is explained in:
> Documentation/security/SELinux-sctp.rst
>
> Signed-off-by: Richard Haines <richard_c_haines at btinternet.com>
> ---
> V5 Change: Rework selinux_netlbl_socket_connect() and
> selinux_netlbl_socket_connect_locked as requested by Paul.
>
> Documentation/security/SELinux-sctp.rst | 157 ++++++++++++++++++
> security/selinux/hooks.c | 280 +++++++++++++++++++++++++++++---
> security/selinux/include/classmap.h | 2 +-
> security/selinux/include/netlabel.h | 21 ++-
> security/selinux/include/objsec.h | 4 +
> security/selinux/netlabel.c | 133 +++++++++++++--
> 6 files changed, 565 insertions(+), 32 deletions(-)
> create mode 100644 Documentation/security/SELinux-sctp.rst
>
> diff --git a/Documentation/security/SELinux-sctp.rst b/Documentation/security/SELinux-sctp.rst
> new file mode 100644
> index 0000000..2f66bf3
> --- /dev/null
> +++ b/Documentation/security/SELinux-sctp.rst
> @@ -0,0 +1,157 @@
> +SCTP SELinux Support
> +=====================
> +
> +Security Hooks
> +===============
> +
> +``Documentation/security/LSM-sctp.rst`` describes the following SCTP security
> +hooks with the SELinux specifics expanded below::
> +
> + security_sctp_assoc_request()
> + security_sctp_bind_connect()
> + security_sctp_sk_clone()
> + security_inet_conn_established()
> +
> +
> +security_sctp_assoc_request()
> +-----------------------------
> +Passes the ``@ep`` and ``@chunk->skb`` of the association INIT packet to the
> +security module. Returns 0 on success, error on failure.
> +::
> +
> + @ep - pointer to sctp endpoint structure.
> + @skb - pointer to skbuff of association packet.
> +
> +The security module performs the following operations:
> + IF this is the first association on ``@ep->base.sk``, then set the peer
> + sid to that in ``@skb``. This will ensure there is only one peer sid
> + assigned to ``@ep->base.sk`` that may support multiple associations.
> +
> + ELSE validate the ``@ep->base.sk peer_sid`` against the ``@skb peer sid``
> + to determine whether the association should be allowed or denied.
> +
> + Set the sctp ``@ep sid`` to socket's sid (from ``ep->base.sk``) with
> + MLS portion taken from ``@skb peer sid``. This will be used by SCTP
> + TCP style sockets and peeled off connections as they cause a new socket
> + to be generated.
> +
> + If IP security options are configured (CIPSO/CALIPSO), then the ip
> + options are set on the socket.
> +
> +
> +security_sctp_bind_connect()
> +-----------------------------
> +Checks permissions required for ipv4/ipv6 addresses based on the ``@optname``
> +as follows::
> +
> + ------------------------------------------------------------------
> + | BIND Permission Checks |
> + | @optname | @address contains |
> + |----------------------------|-----------------------------------|
> + | SCTP_SOCKOPT_BINDX_ADD | One or more ipv4 / ipv6 addresses |
> + | SCTP_PRIMARY_ADDR | Single ipv4 or ipv6 address |
> + | SCTP_SET_PEER_PRIMARY_ADDR | Single ipv4 or ipv6 address |
> + ------------------------------------------------------------------
> +
> + ------------------------------------------------------------------
> + | CONNECT Permission Checks |
> + | @optname | @address contains |
> + |----------------------------|-----------------------------------|
> + | SCTP_SOCKOPT_CONNECTX | One or more ipv4 / ipv6 addresses |
> + | SCTP_PARAM_ADD_IP | One or more ipv4 / ipv6 addresses |
> + | SCTP_SENDMSG_CONNECT | Single ipv4 or ipv6 address |
> + | SCTP_PARAM_SET_PRIMARY | Single ipv4 or ipv6 address |
> + ------------------------------------------------------------------
> +
> +
> +``Documentation/security/LSM-sctp.rst`` gives a summary of the ``@optname``
> +entries and also describes ASCONF chunk processing when Dynamic Address
> +Reconfiguration is enabled.
> +
> +
> +security_sctp_sk_clone()
> +-------------------------
> +Called whenever a new socket is created by **accept**\(2) (i.e. a TCP style
> +socket) or when a socket is 'peeled off' e.g userspace calls
> +**sctp_peeloff**\(3). ``security_sctp_sk_clone()`` will set the new
> +sockets sid and peer sid to that contained in the ``@ep sid`` and
> +``@ep peer sid`` respectively.
> +::
> +
> + @ep - pointer to current sctp endpoint structure.
> + @sk - pointer to current sock structure.
> + @sk - pointer to new sock structure.
> +
> +
> +security_inet_conn_established()
> +---------------------------------
> +Called when a COOKIE ACK is received where it sets the connection's peer sid
> +to that in ``@skb``::
> +
> + @sk - pointer to sock structure.
> + @skb - pointer to skbuff of the COOKIE ACK packet.
> +
> +
> +Policy Statements
> +==================
> +The following class and permissions to support SCTP are available within the
> +kernel::
> +
> + class sctp_socket inherits socket { node_bind }
> +
> +whenever the following policy capability is enabled::
> +
> + policycap extended_socket_class;
> +
> +SELinux SCTP support adds the ``name_connect`` permission for connecting
> +to a specific port type and the ``association`` permission that is explained
> +in the section below.
> +
> +If userspace tools have been updated, SCTP will support the ``portcon``
> +statement as shown in the following example::
> +
> + portcon sctp 1024-1036 system_u:object_r:sctp_ports_t:s0
> +
> +
> +SCTP Peer Labeling
> +===================
> +An SCTP socket will only have one peer label assigned to it. This will be
> +assigned during the establishment of the first association. Once the peer
> +label has been assigned, any new associations will have the ``association``
> +permission validated by checking the socket peer sid against the received
> +packets peer sid to determine whether the association should be allowed or
> +denied.
> +
> +NOTES:
> + 1) If peer labeling is not enabled, then the peer context will always be
> + ``SECINITSID_UNLABELED`` (``unlabeled_t`` in Reference Policy).
> +
> + 2) As SCTP can support more than one transport address per endpoint
> + (multi-homing) on a single socket, it is possible to configure policy
> + and NetLabel to provide different peer labels for each of these. As the
> + socket peer label is determined by the first associations transport
> + address, it is recommended that all peer labels are consistent.
> +
> + 3) **getpeercon**\(3) may be used by userspace to retrieve the sockets peer
> + context.
> +
> + 4) While not SCTP specific, be aware when using NetLabel that if a label
> + is assigned to a specific interface, and that interface 'goes down',
> + then the NetLabel service will remove the entry. Therefore ensure that
> + the network startup scripts call **netlabelctl**\(8) to set the required
> + label (see **netlabel-config**\(8) helper script for details).
> +
> + 5) The NetLabel SCTP peer labeling rules apply as discussed in the following
> + set of posts tagged "netlabel" at: http://www.paul-moore.com/blog/t.
> +
> + 6) CIPSO is only supported for IPv4 addressing: ``socket(AF_INET, ...)``
> + CALIPSO is only supported for IPv6 addressing: ``socket(AF_INET6, ...)``
> +
> + Note the following when testing CIPSO/CALIPSO:
> + a) CIPSO will send an ICMP packet if an SCTP packet cannot be
> + delivered because of an invalid label.
> + b) CALIPSO does not send an ICMP packet, just silently discards it.
> +
> + 7) IPSEC is not supported as RFC 3554 - sctp/ipsec support has not been
> + implemented in userspace (**racoon**\(8) or **ipsec_pluto**\(8)),
> + although the kernel supports SCTP/IPSEC.
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index f5d3047..24d6f39 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -67,6 +67,8 @@
> #include <linux/tcp.h>
> #include <linux/udp.h>
> #include <linux/dccp.h>
> +#include <linux/sctp.h>
> +#include <net/sctp/structs.h>
> #include <linux/quota.h>
> #include <linux/un.h> /* for Unix socket types */
> #include <net/af_unix.h> /* for Unix socket types */
> @@ -4126,6 +4128,23 @@ static int selinux_parse_skb_ipv4(struct sk_buff *skb,
> break;
> }
>
> +#if IS_ENABLED(CONFIG_IP_SCTP)
> + case IPPROTO_SCTP: {
> + struct sctphdr _sctph, *sh;
> +
> + if (ntohs(ih->frag_off) & IP_OFFSET)
> + break;
> +
> + offset += ihlen;
> + sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
> + if (sh == NULL)
> + break;
> +
> + ad->u.net->sport = sh->source;
> + ad->u.net->dport = sh->dest;
> + break;
> + }
> +#endif
> default:
> break;
> }
> @@ -4199,6 +4218,19 @@ static int selinux_parse_skb_ipv6(struct sk_buff *skb,
> break;
> }
>
> +#if IS_ENABLED(CONFIG_IP_SCTP)
> + case IPPROTO_SCTP: {
> + struct sctphdr _sctph, *sh;
> +
> + sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
> + if (sh == NULL)
> + break;
> +
> + ad->u.net->sport = sh->source;
> + ad->u.net->dport = sh->dest;
> + break;
> + }
> +#endif
> /* includes fragments */
> default:
> break;
> @@ -4388,6 +4420,10 @@ static int selinux_socket_post_create(struct socket *sock, int family,
> sksec = sock->sk->sk_security;
> sksec->sclass = sclass;
> sksec->sid = sid;
> + /* Allows detection of the first association on this socket */
> + if (sksec->sclass == SECCLASS_SCTP_SOCKET)
> + sksec->sctp_assoc_state = SCTP_ASSOC_UNSET;
> +
> err = selinux_netlbl_socket_post_create(sock->sk, family);
> }
>
> @@ -4408,11 +4444,7 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
> if (err)
> goto out;
>
> - /*
> - * If PF_INET or PF_INET6, check name_bind permission for the port.
> - * Multiple address binding for SCTP is not supported yet: we just
> - * check the first address now.
> - */
> + /* If PF_INET or PF_INET6, check name_bind permission for the port. */
> family = sk->sk_family;
> if (family == PF_INET || family == PF_INET6) {
> char *addrp;
> @@ -4424,7 +4456,13 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
> unsigned short snum;
> u32 sid, node_perm;
>
> - if (family == PF_INET) {
> + /*
> + * sctp_bindx(3) calls via selinux_sctp_bind_connect()
> + * that validates multiple binding addresses. Because of this
> + * need to check address->sa_family as it is possible to have
> + * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
> + */
> + if (address->sa_family == AF_INET) {
> if (addrlen < sizeof(struct sockaddr_in)) {
> err = -EINVAL;
> goto out;
> @@ -4478,6 +4516,10 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
> node_perm = DCCP_SOCKET__NODE_BIND;
> break;
>
> + case SECCLASS_SCTP_SOCKET:
> + node_perm = SCTP_SOCKET__NODE_BIND;
> + break;
> +
> default:
> node_perm = RAWIP_SOCKET__NODE_BIND;
> break;
> @@ -4492,7 +4534,7 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
> ad.u.net->sport = htons(snum);
> ad.u.net->family = family;
>
> - if (family == PF_INET)
> + if (address->sa_family == AF_INET)
> ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
> else
> ad.u.net->v6info.saddr = addr6->sin6_addr;
> @@ -4506,7 +4548,11 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
> return err;
> }
>
> -static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
> +/* This supports connect(2) and SCTP connect services such as sctp_connectx(3)
> + * and sctp_sendmsg(3) as described in Documentation/security/LSM-sctp.txt
> + */
> +static int selinux_socket_connect_helper(struct socket *sock,
> + struct sockaddr *address, int addrlen)
> {
> struct sock *sk = sock->sk;
> struct sk_security_struct *sksec = sk->sk_security;
> @@ -4517,10 +4563,12 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
> return err;
>
> /*
> - * If a TCP or DCCP socket, check name_connect permission for the port.
> + * If a TCP, DCCP or SCTP socket, check name_connect permission
> + * for the port.
> */
> if (sksec->sclass == SECCLASS_TCP_SOCKET ||
> - sksec->sclass == SECCLASS_DCCP_SOCKET) {
> + sksec->sclass == SECCLASS_DCCP_SOCKET ||
> + sksec->sclass == SECCLASS_SCTP_SOCKET) {
> struct common_audit_data ad;
> struct lsm_network_audit net = {0,};
> struct sockaddr_in *addr4 = NULL;
> @@ -4528,7 +4576,12 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
> unsigned short snum;
> u32 sid, perm;
>
> - if (sk->sk_family == PF_INET) {
> + /* sctp_connectx(3) calls via selinux_sctp_bind_connect()
> + * that validates multiple connect addresses. Because of this
> + * need to check address->sa_family as it is possible to have
> + * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
> + */
> + if (address->sa_family == AF_INET) {
> addr4 = (struct sockaddr_in *)address;
> if (addrlen < sizeof(struct sockaddr_in))
> return -EINVAL;
> @@ -4542,10 +4595,19 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
>
> err = sel_netport_sid(sk->sk_protocol, snum, &sid);
> if (err)
> - goto out;
> + return err;
>
> - perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
> - TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
> + switch (sksec->sclass) {
> + case SECCLASS_TCP_SOCKET:
> + perm = TCP_SOCKET__NAME_CONNECT;
> + break;
> + case SECCLASS_DCCP_SOCKET:
> + perm = DCCP_SOCKET__NAME_CONNECT;
> + break;
> + case SECCLASS_SCTP_SOCKET:
> + perm = SCTP_SOCKET__NAME_CONNECT;
> + break;
> + }
>
> ad.type = LSM_AUDIT_DATA_NET;
> ad.u.net = &net;
> @@ -4553,13 +4615,24 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
> ad.u.net->family = sk->sk_family;
> err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
> if (err)
> - goto out;
> + return err;
> }
>
> - err = selinux_netlbl_socket_connect(sk, address);
> + return 0;
> +}
>
> -out:
> - return err;
> +/* Supports connect(2), see comments in selinux_socket_connect_helper() */
> +static int selinux_socket_connect(struct socket *sock,
> + struct sockaddr *address, int addrlen)
> +{
> + int err;
> + struct sock *sk = sock->sk;
> +
> + err = selinux_socket_connect_helper(sock, address, addrlen);
> + if (err)
> + return err;
> +
> + return selinux_netlbl_socket_connect(sk, address);
> }
>
> static int selinux_socket_listen(struct socket *sock, int backlog)
> @@ -4822,7 +4895,8 @@ static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *op
> u32 peer_sid = SECSID_NULL;
>
> if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
> - sksec->sclass == SECCLASS_TCP_SOCKET)
> + sksec->sclass == SECCLASS_TCP_SOCKET ||
> + sksec->sclass == SECCLASS_SCTP_SOCKET)
> peer_sid = sksec->peer_sid;
> if (peer_sid == SECSID_NULL)
> return -ENOPROTOOPT;
> @@ -4935,6 +5009,171 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
> sksec->sclass = isec->sclass;
> }
>
> +/* Called whenever SCTP receives an INIT chunk. This happens when an incoming
> + * connect(2), sctp_connectx(3) or sctp_sendmsg(3) (with no association
> + * already present).
> + */
> +static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
> + struct sk_buff *skb)
> +{
> + struct sk_security_struct *sksec = ep->base.sk->sk_security;
> + struct common_audit_data ad;
> + struct lsm_network_audit net = {0,};
> + u8 peerlbl_active;
> + u32 peer_sid = SECINITSID_UNLABELED;
> + u32 conn_sid;
> + int err = 0;
> +
> + if (!selinux_policycap_extsockclass)
> + return 0;
> +
> + peerlbl_active = selinux_peerlbl_enabled();
> +
> + if (peerlbl_active) {
> + /* This will return peer_sid = SECSID_NULL if there are
> + * no peer labels, see security_net_peersid_resolve().
> + */
> + err = selinux_skb_peerlbl_sid(skb, ep->base.sk->sk_family,
> + &peer_sid);
> + if (err)
> + return err;
> +
> + if (peer_sid == SECSID_NULL)
> + peer_sid = SECINITSID_UNLABELED;
> + }
> +
> + if (sksec->sctp_assoc_state == SCTP_ASSOC_UNSET) {
> + sksec->sctp_assoc_state = SCTP_ASSOC_SET;
> +
> + /* Here as first association on socket. As the peer SID
> + * was allowed by peer recv (and the netif/node checks),
> + * then it is approved by policy and used as the primary
> + * peer SID for getpeercon(3).
> + */
> + sksec->peer_sid = peer_sid;
> + } else if (sksec->peer_sid != peer_sid) {
> + /* Other association peer SIDs are checked to enforce
> + * consistency among the peer SIDs.
> + */
> + ad.type = LSM_AUDIT_DATA_NET;
> + ad.u.net = &net;
> + ad.u.net->sk = ep->base.sk;
> + err = avc_has_perm(sksec->peer_sid, peer_sid, sksec->sclass,
> + SCTP_SOCKET__ASSOCIATION, &ad);
> + if (err)
> + return err;
> + }
> +
> + /* Compute the MLS component for the connection and store
> + * the information in ep. This will be used by SCTP TCP type
> + * sockets and peeled off connections as they cause a new
> + * socket to be generated. selinux_sctp_sk_clone() will then
> + * plug this into the new socket.
> + */
> + err = selinux_conn_sid(sksec->sid, peer_sid, &conn_sid);
> + if (err)
> + return err;
> +
> + ep->secid = conn_sid;
> + ep->peer_secid = peer_sid;
> +
> + /* Set any NetLabel labels including CIPSO/CALIPSO options. */
> + return selinux_netlbl_sctp_assoc_request(ep, skb);
> +}
> +
> +/* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting
> + * based on their @optname.
> + */
> +static int selinux_sctp_bind_connect(struct sock *sk, int optname,
> + struct sockaddr *address,
> + int addrlen)
> +{
> + int len, err = 0, walk_size = 0;
> + void *addr_buf;
> + struct sockaddr *addr;
> + struct socket *sock;
> +
> + if (!selinux_policycap_extsockclass)
> + return 0;
> +
> + /* Process one or more addresses that may be IPv4 or IPv6 */
> + sock = sk->sk_socket;
> + addr_buf = address;
> +
> + while (walk_size < addrlen) {
> + addr = addr_buf;
> + switch (addr->sa_family) {
> + case AF_INET:
> + len = sizeof(struct sockaddr_in);
> + break;
> + case AF_INET6:
> + len = sizeof(struct sockaddr_in6);
> + break;
> + default:
> + return -EAFNOSUPPORT;
> + }
> +
> + err = -EINVAL;
> + switch (optname) {
> + /* Bind checks */
> + case SCTP_PRIMARY_ADDR:
> + case SCTP_SET_PEER_PRIMARY_ADDR:
> + case SCTP_SOCKOPT_BINDX_ADD:
> + err = selinux_socket_bind(sock, addr, len);
> + break;
> + /* Connect checks */
> + case SCTP_SOCKOPT_CONNECTX:
> + case SCTP_PARAM_SET_PRIMARY:
> + case SCTP_PARAM_ADD_IP:
> + case SCTP_SENDMSG_CONNECT:
> + err = selinux_socket_connect_helper(sock, addr, len);
> + if (err)
> + return err;
> +
> + /* As selinux_sctp_bind_connect() is called by the
> + * SCTP protocol layer, the socket is already locked,
> + * therefore selinux_netlbl_socket_connect_locked() is
> + * is called here. The situations handled are:
> + * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2),
> + * whenever a new IP address is added or when a new
> + * primary address is selected.
> + * Note that an SCTP connect(2) call happens before
> + * the SCTP protocol layer and is handled via
> + * selinux_socket_connect().
> + */
> + err = selinux_netlbl_socket_connect_locked(sk, addr);
> + break;
> + }
> +
> + if (err)
> + return err;
> +
> + addr_buf += len;
> + walk_size += len;
> + }
> +
> + return 0;
> +}
> +
> +/* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */
> +static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
> + struct sock *newsk)
> +{
> + struct sk_security_struct *sksec = sk->sk_security;
> + struct sk_security_struct *newsksec = newsk->sk_security;
> +
> + /* If policy does not support SECCLASS_SCTP_SOCKET then call
> + * the non-sctp clone version.
> + */
> + if (!selinux_policycap_extsockclass)
> + return selinux_sk_clone_security(sk, newsk);
> +
> + newsksec->sid = ep->secid;
> + newsksec->peer_sid = ep->peer_secid;
> + newsksec->sclass = sksec->sclass;
> + selinux_netlbl_sctp_sk_clone(sk, newsk);
> +}
> +
> static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
> struct request_sock *req)
> {
> @@ -6422,6 +6661,9 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
> LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
> LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
> LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
> + LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request),
> + LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone),
> + LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect),
> LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
> LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
> LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
> diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
> index cc35695..167c20a 100644
> --- a/security/selinux/include/classmap.h
> +++ b/security/selinux/include/classmap.h
> @@ -176,7 +176,7 @@ struct security_class_mapping secclass_map[] = {
> { COMMON_CAP2_PERMS, NULL } },
> { "sctp_socket",
> { COMMON_SOCK_PERMS,
> - "node_bind", NULL } },
> + "node_bind", "name_connect", "association", NULL } },
> { "icmp_socket",
> { COMMON_SOCK_PERMS,
> "node_bind", NULL } },
> diff --git a/security/selinux/include/netlabel.h b/security/selinux/include/netlabel.h
> index 75686d5..0fae720 100644
> --- a/security/selinux/include/netlabel.h
> +++ b/security/selinux/include/netlabel.h
> @@ -33,6 +33,7 @@
> #include <linux/skbuff.h>
> #include <net/sock.h>
> #include <net/request_sock.h>
> +#include <net/sctp/structs.h>
>
> #include "avc.h"
> #include "objsec.h"
> @@ -53,9 +54,11 @@ int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
> int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
> u16 family,
> u32 sid);
> -
> +int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
> + struct sk_buff *skb);
> int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family);
> void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family);
> +void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk);
> int selinux_netlbl_socket_post_create(struct sock *sk, u16 family);
> int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
> struct sk_buff *skb,
> @@ -65,6 +68,8 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
> int level,
> int optname);
> int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr);
> +int selinux_netlbl_socket_connect_locked(struct sock *sk,
> + struct sockaddr *addr);
>
> #else
> static inline void selinux_netlbl_cache_invalidate(void)
> @@ -114,6 +119,11 @@ static inline int selinux_netlbl_conn_setsid(struct sock *sk,
> return 0;
> }
>
> +static inline int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
> + struct sk_buff *skb)
> +{
> + return 0;
> +}
> static inline int selinux_netlbl_inet_conn_request(struct request_sock *req,
> u16 family)
> {
> @@ -123,6 +133,10 @@ static inline void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
> {
> return;
> }
> +static inline void selinux_netlbl_sctp_sk_clone(struct sock *sk, sock *newsk)
> +{
> + return;
> +}
> static inline int selinux_netlbl_socket_post_create(struct sock *sk,
> u16 family)
> {
> @@ -146,6 +160,11 @@ static inline int selinux_netlbl_socket_connect(struct sock *sk,
> {
> return 0;
> }
> +static inline int selinux_netlbl_socket_connect_locked(struct sock *sk,
> + struct sockaddr *addr)
> +{
> + return 0;
> +}
> #endif /* CONFIG_NETLABEL */
>
> #endif
> diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
> index 1649cd1..be145cf 100644
> --- a/security/selinux/include/objsec.h
> +++ b/security/selinux/include/objsec.h
> @@ -130,6 +130,10 @@ struct sk_security_struct {
> u32 sid; /* SID of this object */
> u32 peer_sid; /* SID of peer */
> u16 sclass; /* sock security class */
> + enum { /* SCTP association state */
> + SCTP_ASSOC_UNSET = 0,
> + SCTP_ASSOC_SET,
> + } sctp_assoc_state;
> };
>
> struct tun_security_struct {
> diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
> index aaba667..0863c56 100644
> --- a/security/selinux/netlabel.c
> +++ b/security/selinux/netlabel.c
> @@ -250,6 +250,7 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
> sk = skb_to_full_sk(skb);
> if (sk != NULL) {
> struct sk_security_struct *sksec = sk->sk_security;
> +
> if (sksec->nlbl_state != NLBL_REQSKB)
> return 0;
> secattr = selinux_netlbl_sock_getattr(sk, sid);
> @@ -270,6 +271,61 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
> return rc;
> }
>
> +/**
> + * selinux_netlbl_sctp_assoc_request - Label an incoming sctp association.
> + * @ep: incoming association endpoint.
> + * @skb: the packet.
> + *
> + * Description:
> + * A new incoming connection is represented by @ep, ......
> + * Returns zero on success, negative values on failure.
> + *
> + */
> +int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
> + struct sk_buff *skb)
> +{
> + int rc;
> + struct netlbl_lsm_secattr secattr;
> + struct sk_security_struct *sksec = ep->base.sk->sk_security;
> + struct sockaddr *addr;
> + struct sockaddr_in addr4;
> +#if IS_ENABLED(CONFIG_IPV6)
> + struct sockaddr_in6 addr6;
> +#endif
> +
> + if (ep->base.sk->sk_family != PF_INET &&
> + ep->base.sk->sk_family != PF_INET6)
> + return 0;
> +
> + netlbl_secattr_init(&secattr);
> + rc = security_netlbl_sid_to_secattr(ep->secid, &secattr);
> + if (rc != 0)
> + goto assoc_request_return;
> +
> + /* Move skb hdr address info to a struct sockaddr and then call
> + * netlbl_conn_setattr().
> + */
> + if (ip_hdr(skb)->version == 4) {
> + addr4.sin_family = AF_INET;
> + addr4.sin_addr.s_addr = ip_hdr(skb)->saddr;
> + addr = (struct sockaddr *)&addr4;
> +#if IS_ENABLED(CONFIG_IPV6)
> + } else {
> + addr6.sin6_family = AF_INET6;
> + addr6.sin6_addr = ipv6_hdr(skb)->saddr;
> + addr = (struct sockaddr *)&addr6;
> +#endif
> + }
> +
> + rc = netlbl_conn_setattr(ep->base.sk, addr, &secattr);
> + if (rc == 0)
> + sksec->nlbl_state = NLBL_LABELED;
> +
> +assoc_request_return:
> + netlbl_secattr_destroy(&secattr);
> + return rc;
> +}
> +
> /**
> * selinux_netlbl_inet_conn_request - Label an incoming stream connection
> * @req: incoming connection request socket
> @@ -319,6 +375,22 @@ void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
> sksec->nlbl_state = NLBL_UNSET;
> }
>
> +/**
> + * selinux_netlbl_sctp_sk_clone - Copy state to the newly created sock
> + * @sk: current sock
> + * @newsk: the new sock
> + *
> + * Description:
> + * Called whenever a new socket is created by accept(2) or sctp_peeloff(3).
> + */
> +void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
> +{
> + struct sk_security_struct *sksec = sk->sk_security;
> + struct sk_security_struct *newsksec = newsk->sk_security;
> +
> + newsksec->nlbl_state = sksec->nlbl_state;
> +}
> +
> /**
> * selinux_netlbl_socket_post_create - Label a socket using NetLabel
> * @sock: the socket to label
> @@ -470,7 +542,8 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
> }
>
> /**
> - * selinux_netlbl_socket_connect - Label a client-side socket on connect
> + * selinux_netlbl_socket_connect_helper - Help label a client-side socket on
> + * connect
> * @sk: the socket to label
> * @addr: the destination address
> *
> @@ -479,18 +552,13 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
> * Returns zero values on success, negative values on failure.
> *
> */
> -int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
> +static int selinux_netlbl_socket_connect_helper(struct sock *sk,
> + struct sockaddr *addr)
> {
> int rc;
> struct sk_security_struct *sksec = sk->sk_security;
> struct netlbl_lsm_secattr *secattr;
>
> - if (sksec->nlbl_state != NLBL_REQSKB &&
> - sksec->nlbl_state != NLBL_CONNLABELED)
> - return 0;
> -
> - lock_sock(sk);
> -
> /* connected sockets are allowed to disconnect when the address family
> * is set to AF_UNSPEC, if that is what is happening we want to reset
> * the socket */
> @@ -498,18 +566,61 @@ int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
> netlbl_sock_delattr(sk);
> sksec->nlbl_state = NLBL_REQSKB;
> rc = 0;
> - goto socket_connect_return;
> + return rc;
> }
> secattr = selinux_netlbl_sock_genattr(sk);
> if (secattr == NULL) {
> rc = -ENOMEM;
> - goto socket_connect_return;
> + return rc;
> }
> rc = netlbl_conn_setattr(sk, addr, secattr);
> if (rc == 0)
> sksec->nlbl_state = NLBL_CONNLABELED;
>
> -socket_connect_return:
> + return rc;
> +}
> +
> +/**
> + * selinux_netlbl_socket_connect_locked - Label a client-side socket on
> + * connect
> + * @sk: the socket to label
> + * @addr: the destination address
> + *
> + * Description:
> + * Attempt to label a connected socket that already has the socket locked
> + * with NetLabel using the given address.
> + * Returns zero values on success, negative values on failure.
> + *
> + */
> +int selinux_netlbl_socket_connect_locked(struct sock *sk,
> + struct sockaddr *addr)
> +{
> + struct sk_security_struct *sksec = sk->sk_security;
> +
> + if (sksec->nlbl_state != NLBL_REQSKB &&
> + sksec->nlbl_state != NLBL_CONNLABELED)
> + return 0;
> +
> + return selinux_netlbl_socket_connect_helper(sk, addr);
> +}
> +
> +/**
> + * selinux_netlbl_socket_connect - Label a client-side socket on connect
> + * @sk: the socket to label
> + * @addr: the destination address
> + *
> + * Description:
> + * Attempt to label a connected socket with NetLabel using the given address.
> + * Returns zero values on success, negative values on failure.
> + *
> + */
> +int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
> +{
> + int rc;
> +
> + lock_sock(sk);
> + rc = selinux_netlbl_socket_connect_locked(sk, addr);
> release_sock(sk);
> +
> return rc;
> }
> --
> 2.14.3
>
> --
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> the body of a message to majordomo at vger.kernel.org
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>
Acked-by: Neil Horman <nhorman at tuxdriver.com>
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