Discussion:
[PATCH v3 0/4] Add SELinux SCTP protocol support
Marcelo Ricardo Leitner
2017-12-22 13:05:15 UTC
Permalink
Posting on behalf of Richard Haines. Patchset is based on
selinux-tree/next. Some small conflicts are expected when merging with
current net-next due to I-Data patches, including one at
include/uapi/linux/sctp.h, on which the fix is to update the define
SCTP_SENDMSG_CONNECT to a higher number.
Below is the original cover letter from Richard, and the changes from
v2->v3.

The kernel patches have been built on Fedora 27 with kernel 4.13.12 plus
the following userspace patches to enable testing:

1) Updates to libsepol 2.7 to support the sctp portcon statement.
The patch is available from:
http://arctic.selinuxproject.org/~rhaines/selinux-sctp/
selinux-Add-support-for-the-SCTP-portcon-keyword.patch

2) Updates to the SELinux Test Suite adding SCTP tests. Please read the
selinux-testsuite/README.sctp for details. The patch is available from:
http://arctic.selinuxproject.org/~rhaines/selinux-sctp/
selinux-testsuite-Add-SCTP-test-support.patch

3) Updates to lksctp-tools that show SELinux info in sctp_darn and
sctp_test. It also contains a minor patch for test_1_to_1_connect.c
as when CIPSO/CALIPSO configured, NetLabel returns a different error
code for illegal addresses in test 5. The patch is available from:
http://arctic.selinuxproject.org/~rhaines/selinux-sctp/
lksctp-tools-Add-SELinux-support-to-sctp_test-and-sc.patch

All SCTP lksctp-tools/src/func_tests run correctly in enforcing mode.

All SCTP regression tests "./sctp-tests run" run correctly in enforcing
mode. These tests are obtained from: https://github.com/sctp/sctp-tests

The selinux-testsuite patch also adds remote tests (that need some manual
configuration). These are useful for testing CIPSO/CALIPSO over a network
with a number of categories to produce large ip option fields with various
message sizes forcing fragmentation etc..

Changes since RFC Patch:
Removed the NetLabel patch (was [RFC PATCH 4/5] netlabel: Add SCTP support)
as re-engineered. However this patchset will require the NetLabel
patch at [1] to fully run the SCTP selinux-testsuite.

PATCH 1/4
Remove unused parameter from security_sctp_assoc_request().
Reformat and update LSM-sctp.rst documentation.
PATCH 2/4
Add variables and RCU locks as requested in [2] to support IP options.
PATCH 3/4
Added security_sctp_assoc_request() hook to sctp_sf_do_unexpected_init()
and sctp_sf_do_5_2_4_dupcook().
Removed security_sctp_assoc_request() hook from sctp_sf_do_5_1C_ack() as
no longer required.
PATCH 4/4
Reformat and update SELinux-sctp.rst documentation.
Remove bindx and connectx permissions.
Rework selinux_socket_connect() and selinux_netlbl_socket_connect() to
utilise helpers for code reuse.
Add spinlock to selinux_sctp_assoc_request().
Remove unused parameter from security_sctp_assoc_request().
Use address->sa_family == AF_INET in *_bind and *_connect to ensure
correct address type.
Minor cleanups.

Changes since v2 post by Richard:
Updated sctp_frag_point() to also consider the ip options len.

[1] https://marc.info/?l=selinux&m=151061619115945&w=2
[2] https://marc.info/?l=selinux&m=150962470215797&w=2


Richard Haines (4):
security: Add support for SCTP security hooks
sctp: Add ip option support
sctp: Add LSM hooks
selinux: Add SCTP support

Documentation/security/LSM-sctp.rst | 194 ++++++++++++++++++++++
Documentation/security/SELinux-sctp.rst | 104 ++++++++++++
include/linux/lsm_hooks.h | 35 ++++
include/linux/security.h | 25 +++
include/net/sctp/sctp.h | 4 +-
include/net/sctp/structs.h | 12 ++
include/uapi/linux/sctp.h | 1 +
net/sctp/chunk.c | 13 +-
net/sctp/ipv6.c | 42 ++++-
net/sctp/output.c | 5 +-
net/sctp/protocol.c | 36 +++++
net/sctp/sm_make_chunk.c | 12 ++
net/sctp/sm_statefuns.c | 18 +++
net/sctp/socket.c | 70 +++++++-
security/security.c | 22 +++
security/selinux/hooks.c | 278 +++++++++++++++++++++++++++++---
security/selinux/include/classmap.h | 2 +-
security/selinux/include/netlabel.h | 15 +-
security/selinux/include/objsec.h | 4 +
security/selinux/netlabel.c | 128 +++++++++++++--
20 files changed, 971 insertions(+), 49 deletions(-)
create mode 100644 Documentation/security/LSM-sctp.rst
create mode 100644 Documentation/security/SELinux-sctp.rst
--
2.14.3
Marcelo Ricardo Leitner
2017-12-22 13:05:18 UTC
Permalink
From: Richard Haines <***@btinternet.com>

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

Signed-off-by: Richard Haines <***@btinternet.com>
Acked-by: Marcelo Ricardo Leitner <***@gmail.com>
---
include/net/sctp/structs.h | 10 ++++++++
include/uapi/linux/sctp.h | 1 +
net/sctp/sm_make_chunk.c | 12 +++++++++
net/sctp/sm_statefuns.c | 18 ++++++++++++++
net/sctp/socket.c | 61 +++++++++++++++++++++++++++++++++++++++++++++-
5 files changed, 101 insertions(+), 1 deletion(-)

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 9942ed5159448c924f0f018abeea9bab93fc3437..2ca0a3f7f043316d15d9d0998f035a0820bac1a3 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1271,6 +1271,16 @@ 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 6217ff8500a1d818fd1002fbd6f81c0c11974665..c04812f41068fd50978ebb6cf2578c7750c86efe 100644
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h
@@ -122,6 +122,7 @@ typedef __s32 sctp_assoc_t;
#define SCTP_RESET_ASSOC 120
#define SCTP_ADD_STREAMS 121
#define SCTP_SOCKOPT_PEELOFF_FLAGS 122
+#define SCTP_SENDMSG_CONNECT 123

/* 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 ca8f196b6c6c106386a65c75dccd7bc3451798ff..140e45b931ee83c835eddce693ec51a94d19b26a 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -3054,6 +3054,12 @@ 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
@@ -3120,6 +3126,12 @@ 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 8f8ccded13e47c4b5403b5a27416b0d5707d1f33..a2dfc5ad17921987ddd35190a5d36460b3f7e558 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -318,6 +318,11 @@ 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.
@@ -905,6 +910,9 @@ 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
@@ -1433,6 +1441,11 @@ 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.
@@ -2103,6 +2116,11 @@ 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 274082cf49a8380fda06866c631cdc22dc4f157b..d7822da004e90f12e523b132491d177d37468753 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1015,6 +1015,12 @@ 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;
@@ -1224,6 +1230,7 @@ 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.
@@ -1337,9 +1344,17 @@ static int __sctp_setsockopt_connectx(struct sock *sk,
if (__copy_from_user(kaddrs, addrs, addrs_size)) {
err = -EFAULT;
} else {
+ /* 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:
kfree(kaddrs);

return err;
@@ -1606,6 +1621,7 @@ 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;
@@ -1835,6 +1851,24 @@ 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;
@@ -2867,6 +2901,8 @@ 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;
@@ -2874,6 +2910,17 @@ 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;
@@ -3196,6 +3243,13 @@ 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);
@@ -8038,6 +8092,8 @@ 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;
@@ -8080,7 +8136,10 @@ 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,
--
2.14.3
Marcelo Ricardo Leitner
2017-12-22 13:05:19 UTC
Permalink
From: Richard Haines <***@btinternet.com>

The SELinux SCTP implementation is explained in:
Documentation/security/SELinux-sctp.rst

Signed-off-by: Richard Haines <***@btinternet.com>
Acked-by: Marcelo Ricardo Leitner <***@gmail.com>
---
Documentation/security/SELinux-sctp.rst | 104 ++++++++++++
security/selinux/hooks.c | 278 +++++++++++++++++++++++++++++---
security/selinux/include/classmap.h | 2 +-
security/selinux/include/netlabel.h | 15 +-
security/selinux/include/objsec.h | 4 +
security/selinux/netlabel.c | 128 +++++++++++++--
6 files changed, 499 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 0000000000000000000000000000000000000000..f6a9162d3d61e766e2c36fa001c08a1073c1b02e
--- /dev/null
+++ b/Documentation/security/SELinux-sctp.rst
@@ -0,0 +1,104 @@
+SCTP SELinux Support
+=====================
+
+Security Hooks
+===============
+
+The ``Documentation/security/LSM-sctp.rst`` document describes how the
+following sctp security hooks are utilised::
+
+ security_sctp_assoc_request()
+ security_sctp_bind_connect()
+ security_sctp_sk_clone()
+ security_inet_conn_established()
+
+
+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 Bind, Connect and ASCONF Chunk Parameter Permission Checks
+================================================================
+The hook ``security_sctp_bind_connect()`` is called by SCTP to check
+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 |
+ ------------------------------------------------------------------
+
+
+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 f21f1e0e6452570c48cac09dc5c76a6b726c00eb..9ffa5792f570f0751f7bd46418eec2b3fc6489ae 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 */
@@ -4117,6 +4119,23 @@ 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;
}
@@ -4190,6 +4209,19 @@ 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;
@@ -4379,6 +4411,10 @@ 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);
}

@@ -4399,11 +4435,7 @@ 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;
@@ -4415,7 +4447,13 @@ 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;
@@ -4469,6 +4507,10 @@ 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;
@@ -4483,7 +4525,7 @@ 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;
@@ -4497,7 +4539,11 @@ 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;
@@ -4508,10 +4554,12 @@ 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;
@@ -4519,7 +4567,12 @@ 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;
@@ -4533,10 +4586,19 @@ 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;
@@ -4544,13 +4606,24 @@ 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)
@@ -4813,7 +4886,8 @@ 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;
@@ -4926,6 +5000,169 @@ 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).
+ * The lock is to ensure sksec->sctp_assoc_state.
+ */
+static DEFINE_SPINLOCK(assoc_lock);
+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;
+
+ spin_lock(&assoc_lock);
+
+ 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)
+ goto 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)
+ goto 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)
+ goto err;
+
+ ep->secid = conn_sid;
+ ep->peer_secid = peer_sid;
+
+ /* Set any NetLabel labels including CIPSO/CALIPSO options. */
+ err = selinux_netlbl_sctp_assoc_request(ep, skb);
+
+err:
+ spin_unlock(&assoc_lock);
+ return err;
+}
+
+/*
+ * 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;
+
+ err = selinux_netlbl_sctp_socket_connect(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;
+ newsksec->nlbl_state = sksec->nlbl_state;
+}
+
static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
@@ -6413,6 +6650,9 @@ 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 35ffb29a69cb00b34a4de5d722eaee46df310a74..099065e0a9e099aaf26b765093796caaf7c365ee 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -175,7 +175,7 @@ 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 e77a5e307955bf938f293f29a3b7be8421fc3533..70275c5e8ee8b254e3a5e3e4a984080a2810ef1c 100644
--- a/security/selinux/include/netlabel.h
+++ b/security/selinux/include/netlabel.h
@@ -32,6 +32,7 @@
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/request_sock.h>
+#include <net/sctp/structs.h>

#include "avc.h"
#include "objsec.h"
@@ -52,7 +53,8 @@ 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);
int selinux_netlbl_socket_post_create(struct sock *sk, u16 family);
@@ -64,6 +66,7 @@ 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_sctp_socket_connect(struct sock *sk, struct sockaddr *addr);

#else
static inline void selinux_netlbl_cache_invalidate(void)
@@ -113,6 +116,11 @@ 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)
{
@@ -145,6 +153,11 @@ static inline int selinux_netlbl_socket_connect(struct sock *sk,
{
return 0;
}
+static inline int selinux_netlbl_sctp_socket_connect(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 1649cd18eb0bed125bb38466506309d26c647f90..be145cfe518a409b8b47b74589949c4ea1d5aabf 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 2c297b995b169519978c4fdedd981743add3e7cc..75066f5f98fd65b6b939a2ea8f1117149ca21957 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -249,6 +249,7 @@ 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);
@@ -269,6 +270,61 @@ 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
@@ -469,7 +525,8 @@ 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
*
@@ -478,18 +535,13 @@ 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 */
@@ -497,18 +549,72 @@ 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 - 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;
+ struct sk_security_struct *sksec = sk->sk_security;
+
+ if (sksec->nlbl_state != NLBL_REQSKB &&
+ sksec->nlbl_state != NLBL_CONNLABELED)
+ return 0;
+
+ lock_sock(sk);
+ rc = selinux_netlbl_socket_connect_helper(sk, addr);
release_sock(sk);
+
+ return rc;
+}
+
+/**
+ * selinux_netlbl_sctp_socket_connect - Label an SCTP client-side socket on a
+ * connect
+ * @sk: the socket to label
+ * @addr: the destination address
+ *
+ * Description:
+ * Attempt to label a connected socket with NetLabel using the given address
+ * when called by the SCTP protocol layer. 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_netlbl_socket_connect()
+ * Returns zero values on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_sctp_socket_connect(struct sock *sk, struct sockaddr *addr)
+{
+ int rc;
+ struct sk_security_struct *sksec = sk->sk_security;
+
+ if (sksec->nlbl_state != NLBL_REQSKB &&
+ sksec->nlbl_state != NLBL_CONNLABELED)
+ return 0;
+
+ rc = selinux_netlbl_socket_connect_helper(sk, addr);
+
return rc;
}
--
2.14.3
Marcelo Ricardo Leitner
2017-12-22 13:05:16 UTC
Permalink
From: Richard Haines <***@btinternet.com>

The SCTP security hooks are explained in:
Documentation/security/LSM-sctp.rst

Signed-off-by: Richard Haines <***@btinternet.com>
Acked-by: Marcelo Ricardo Leitner <***@gmail.com>
---
Documentation/security/LSM-sctp.rst | 194 ++++++++++++++++++++++++++++++++++++
include/linux/lsm_hooks.h | 35 +++++++
include/linux/security.h | 25 +++++
security/security.c | 22 ++++
4 files changed, 276 insertions(+)
create mode 100644 Documentation/security/LSM-sctp.rst

diff --git a/Documentation/security/LSM-sctp.rst b/Documentation/security/LSM-sctp.rst
new file mode 100644
index 0000000000000000000000000000000000000000..61373672ce9f63bbd52d953500f44cdf3427c3f0
--- /dev/null
+++ b/Documentation/security/LSM-sctp.rst
@@ -0,0 +1,194 @@
+SCTP LSM Support
+================
+
+For security module support, three sctp specific hooks have been implemented::
+
+ security_sctp_assoc_request()
+ security_sctp_bind_connect()
+ security_sctp_sk_clone()
+
+Also the following security hook has been utilised::
+
+ security_inet_conn_established()
+
+The usage of these hooks are described below with the SELinux implementation
+described in ``Documentation/security/SELinux-sctp.rst``
+
+
+security_sctp_assoc_request()
+-----------------------------
+This new hook passes the ``@ep`` and ``@chunk->skb`` (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()
+-----------------------------
+This new hook passes one or more ipv4/ipv6 addresses to the security module
+for validation based on the ``@optname`` that will result in either a bind or
+connect service as shown in the permission check tables below.
+Returns 0 on success, error on failure.
+::
+
+ @sk - Pointer to sock structure.
+ @optname - Name of the option to validate.
+ @address - One or more ipv4 / ipv6 addresses.
+ @addrlen - The total length of address(s). This is calculated on each
+ ipv4 or ipv6 address using sizeof(struct sockaddr_in) or
+ sizeof(struct sockaddr_in6).
+
+ ------------------------------------------------------------------
+ | BIND Type 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 Type 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 |
+ ------------------------------------------------------------------
+
+A summary of the ``@optname`` entries is as follows::
+
+ SCTP_SOCKOPT_BINDX_ADD - Allows additional bind addresses to be
+ associated after (optionally) calling
+ bind(3).
+ sctp_bindx(3) adds a set of bind
+ addresses on a socket.
+
+ SCTP_SOCKOPT_CONNECTX - Allows the allocation of multiple
+ addresses for reaching a peer
+ (multi-homed).
+ sctp_connectx(3) initiates a connection
+ on an SCTP socket using multiple
+ destination addresses.
+
+ SCTP_SENDMSG_CONNECT - Initiate a connection that is generated by a
+ sendmsg(2) or sctp_sendmsg(3) on a new asociation.
+
+ SCTP_PRIMARY_ADDR - Set local primary address.
+
+ SCTP_SET_PEER_PRIMARY_ADDR - Request peer sets address as
+ association primary.
+
+ SCTP_PARAM_ADD_IP - These are used when Dynamic Address
+ SCTP_PARAM_SET_PRIMARY - Reconfiguration is enabled as explained below.
+
+
+To support Dynamic Address Reconfiguration the following parameters must be
+enabled on both endpoints (or use the appropriate **setsockopt**\(2))::
+
+ /proc/sys/net/sctp/addip_enable
+ /proc/sys/net/sctp/addip_noauth_enable
+
+then the following *_PARAM_*'s are sent to the peer in an
+ASCONF chunk when the corresponding ``@optname``'s are present::
+
+ @optname ASCONF Parameter
+ ---------- ------------------
+ SCTP_SOCKOPT_BINDX_ADD -> SCTP_PARAM_ADD_IP
+ SCTP_SET_PEER_PRIMARY_ADDR -> SCTP_PARAM_SET_PRIMARY
+
+
+security_sctp_sk_clone()
+-------------------------
+This new hook is 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 old sctp endpoint structure.
+ @sk - pointer to old sock structure.
+ @sk - pointer to new sock structure.
+
+
+security_inet_conn_established()
+---------------------------------
+This hook has been added to the receive COOKIE ACK processing 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.
+
+
+Security Hooks used for Association Establishment
+=================================================
+The following diagram shows the use of ``security_sctp_connect_bind()``,
+``security_sctp_assoc_request()``, ``security_inet_conn_established()`` when
+establishing an association.
+::
+
+ SCTP endpoint "A" SCTP endpoint "Z"
+ ================= =================
+ sctp_sf_do_prm_asoc()
+ Association setup can be initiated
+ by a connect(2), sctp_connectx(3),
+ sendmsg(2) or sctp_sendmsg(3).
+ These will result in a call to
+ security_sctp_bind_connect() to
+ initiate an association to
+ SCTP peer endpoint "Z".
+ INIT --------------------------------------------->
+ sctp_sf_do_5_1B_init()
+ Respond to an INIT chunk.
+ SCTP peer endpoint "A" is
+ asking for an association. Call
+ security_sctp_assoc_request()
+ to set the peer label if first
+ association.
+ If not first association, check
+ whether allowed, IF so send:
+ <----------------------------------------------- INIT ACK
+ | ELSE audit event and silently
+ | discard the packet.
+ |
+ COOKIE ECHO ------------------------------------------>
+ |
+ |
+ |
+ <------------------------------------------- COOKIE ACK
+ | |
+ sctp_sf_do_5_1E_ca |
+ Call security_inet_conn_established() |
+ to set the correct peer sid. |
+ | |
+ | If SCTP_SOCKET_TCP or peeled off
+ | socket security_sctp_sk_clone() is
+ | called to clone the new socket.
+ | |
+ ESTABLISHED ESTABLISHED
+ | |
+ ------------------------------------------------------------------
+ | Association Established |
+ ------------------------------------------------------------------
+
+
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index c9258124e41757187cdb8b2f83c5901966345902..92ee9c6c604212ce38590bd2e5fcba55617b9c04 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -906,6 +906,32 @@
* associated with the TUN device's security structure.
* @security pointer to the TUN devices's security structure.
*
+ * Security hooks for SCTP
+ *
+ * @sctp_assoc_request:
+ * If first association, then set the peer sid to that in @skb. If
+ * @sctp_cid is from an INIT chunk, then set the sctp endpoint sid to
+ * socket's sid (ep->base.sk) with MLS portion taken from peer sid.
+ * @ep pointer to sctp endpoint structure.
+ * @skb pointer to skbuff of association packet.
+ * Return 0 on success, error on failure.
+ * @sctp_bind_connect:
+ * Validiate permissions required for each address associated with sock
+ * @sk. Depending on @optname, the addresses will be treated as either
+ * for a connect or bind service. The @addrlen is calculated on each
+ * ipv4 and ipv6 address using sizeof(struct sockaddr_in) or
+ * sizeof(struct sockaddr_in6).
+ * @sk pointer to sock structure.
+ * @optname name of the option to validate.
+ * @address list containing one or more ipv4/ipv6 addresses.
+ * @addrlen total length of address(s).
+ * Return 0 on success, error on failure.
+ * @sctp_sk_clone:
+ * Sets the new child socket's sid to the old endpoint sid.
+ * @ep pointer to old sctp endpoint structure.
+ * @sk pointer to old sock structure.
+ * @sk pointer to new sock structure.
+ *
* Security hooks for Infiniband
*
* @ib_pkey_access:
@@ -1631,6 +1657,12 @@ union security_list_options {
int (*tun_dev_attach_queue)(void *security);
int (*tun_dev_attach)(struct sock *sk, void *security);
int (*tun_dev_open)(void *security);
+ int (*sctp_assoc_request)(struct sctp_endpoint *ep,
+ struct sk_buff *skb);
+ int (*sctp_bind_connect)(struct sock *sk, int optname,
+ struct sockaddr *address, int addrlen);
+ void (*sctp_sk_clone)(struct sctp_endpoint *ep, struct sock *sk,
+ struct sock *newsk);
#endif /* CONFIG_SECURITY_NETWORK */

#ifdef CONFIG_SECURITY_INFINIBAND
@@ -1869,6 +1901,9 @@ struct security_hook_heads {
struct list_head tun_dev_attach_queue;
struct list_head tun_dev_attach;
struct list_head tun_dev_open;
+ struct list_head sctp_assoc_request;
+ struct list_head sctp_bind_connect;
+ struct list_head sctp_sk_clone;
#endif /* CONFIG_SECURITY_NETWORK */
#ifdef CONFIG_SECURITY_INFINIBAND
struct list_head ib_pkey_access;
diff --git a/include/linux/security.h b/include/linux/security.h
index ce6265960d6c430a90e1ad3c3749d0a438ecaca9..51f6cc2417f278674dfbd434587af805cb0c03d3 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -115,6 +115,7 @@ struct xfrm_policy;
struct xfrm_state;
struct xfrm_user_sec_ctx;
struct seq_file;
+struct sctp_endpoint;

#ifdef CONFIG_MMU
extern unsigned long mmap_min_addr;
@@ -1229,6 +1230,11 @@ int security_tun_dev_create(void);
int security_tun_dev_attach_queue(void *security);
int security_tun_dev_attach(struct sock *sk, void *security);
int security_tun_dev_open(void *security);
+int security_sctp_assoc_request(struct sctp_endpoint *ep, struct sk_buff *skb);
+int security_sctp_bind_connect(struct sock *sk, int optname,
+ struct sockaddr *address, int addrlen);
+void security_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
+ struct sock *newsk);

#else /* CONFIG_SECURITY_NETWORK */
static inline int security_unix_stream_connect(struct sock *sock,
@@ -1421,6 +1427,25 @@ static inline int security_tun_dev_open(void *security)
{
return 0;
}
+
+static inline int security_sctp_assoc_request(struct sctp_endpoint *ep,
+ struct sk_buff *skb)
+{
+ return 0;
+}
+
+static inline int security_sctp_bind_connect(struct sock *sk, int optname,
+ struct sockaddr *address,
+ int addrlen)
+{
+ return 0;
+}
+
+static inline void security_sctp_sk_clone(struct sctp_endpoint *ep,
+ struct sock *sk,
+ struct sock *newsk)
+{
+}
#endif /* CONFIG_SECURITY_NETWORK */

#ifdef CONFIG_SECURITY_INFINIBAND
diff --git a/security/security.c b/security/security.c
index 4bf0f571b4ef94df1d3c44b7fed6b7b651c1924f..1400678f6b72b36123f2fa2b909f35d257a62cd4 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1472,6 +1472,7 @@ void security_inet_conn_established(struct sock *sk,
{
call_void_hook(inet_conn_established, sk, skb);
}
+EXPORT_SYMBOL(security_inet_conn_established);

int security_secmark_relabel_packet(u32 secid)
{
@@ -1527,6 +1528,27 @@ int security_tun_dev_open(void *security)
}
EXPORT_SYMBOL(security_tun_dev_open);

+int security_sctp_assoc_request(struct sctp_endpoint *ep, struct sk_buff *skb)
+{
+ return call_int_hook(sctp_assoc_request, 0, ep, skb);
+}
+EXPORT_SYMBOL(security_sctp_assoc_request);
+
+int security_sctp_bind_connect(struct sock *sk, int optname,
+ struct sockaddr *address, int addrlen)
+{
+ return call_int_hook(sctp_bind_connect, 0, sk, optname,
+ address, addrlen);
+}
+EXPORT_SYMBOL(security_sctp_bind_connect);
+
+void security_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
+ struct sock *newsk)
+{
+ call_void_hook(sctp_sk_clone, ep, sk, newsk);
+}
+EXPORT_SYMBOL(security_sctp_sk_clone);
+
#endif /* CONFIG_SECURITY_NETWORK */

#ifdef CONFIG_SECURITY_INFINIBAND
--
2.14.3
Richard Haines
2017-12-27 16:22:21 UTC
Permalink
Post by Marcelo Ricardo Leitner
Documentation/security/LSM-sctp.rst
Thanks Casey for your comments. However, I'm not that acquainted with
these area of codes and I cannot work on them. I'll just wait for
Richard then.
I'm back online and will post a V4 set of patches within a week. These
will address Paul's comments as per [1] and Casey's regarding the
documentation.
Sorry for the delay


[1] https://marc.info/?l=selinux&m=151274018809822&w=2
Marcelo
--
To unsubscribe from this list: send the line "unsubscribe linux-sctp"
in
More majordomo info at http://vger.kernel.org/majordomo-info.html
Paul Moore
2017-12-27 20:35:46 UTC
Permalink
On Wed, Dec 27, 2017 at 11:22 AM, Richard Haines
Post by Richard Haines
Post by Marcelo Ricardo Leitner
Documentation/security/LSM-sctp.rst
Thanks Casey for your comments. However, I'm not that acquainted with
these area of codes and I cannot work on them. I'll just wait for
Richard then.
I'm back online and will post a V4 set of patches within a week. These
will address Paul's comments as per [1] and Casey's regarding the
documentation.
Sorry for the delay
No worries, thanks.
--
paul moore
www.paul-moore.com
Marcelo Ricardo Leitner
2017-12-22 13:05:17 UTC
Permalink
From: Richard Haines <***@btinternet.com>

Add ip option support to allow LSM security modules to utilise CIPSO/IPv4
and CALIPSO/IPv6 services.

Signed-off-by: Richard Haines <***@btinternet.com>
Acked-by: Marcelo Ricardo Leitner <***@gmail.com>
---
include/net/sctp/sctp.h | 4 +++-
include/net/sctp/structs.h | 2 ++
net/sctp/chunk.c | 13 ++++++++-----
net/sctp/ipv6.c | 42 +++++++++++++++++++++++++++++++++++-------
net/sctp/output.c | 5 ++++-
net/sctp/protocol.c | 36 ++++++++++++++++++++++++++++++++++++
net/sctp/socket.c | 9 +++++++--
7 files changed, 95 insertions(+), 16 deletions(-)

diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index d7d8cba014697602832fe20e414b632104c9f239..1b2f40a3a87875c10647fc768372cabea61fe3b8 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -436,9 +436,11 @@ static inline int sctp_list_single_entry(struct list_head *head)
static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
{
struct sctp_sock *sp = sctp_sk(asoc->base.sk);
+ struct sctp_af *af = sp->pf->af;
int frag = pmtu;

- frag -= sp->pf->af->net_header_len;
+ frag -= af->ip_options_len(asoc->base.sk);
+ frag -= af->net_header_len;
frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);

if (asoc->user_frag)
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 0477945de1a3cf5c27348e99d9a30e02c491d1de..9942ed5159448c924f0f018abeea9bab93fc3437 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -461,6 +461,7 @@ struct sctp_af {
void (*ecn_capable)(struct sock *sk);
__u16 net_header_len;
int sockaddr_len;
+ int (*ip_options_len)(struct sock *sk);
sa_family_t sa_family;
struct list_head list;
};
@@ -485,6 +486,7 @@ struct sctp_pf {
int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
+ void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
struct sctp_af *af;
};

diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
index 3afac275ee82dbec825dd71378dffe69a53718a7..9d130f447f636c034e4232a9e6426ffce07007ca 100644
--- a/net/sctp/chunk.c
+++ b/net/sctp/chunk.c
@@ -153,7 +153,6 @@ static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chu
chunk->msg = msg;
}

-
/* A data chunk can have a maximum payload of (2^16 - 20). Break
* down any such message into smaller chunks. Opportunistically, fragment
* the chunks down to the current MTU constraints. We may get refragmented
@@ -170,6 +169,8 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
struct list_head *pos, *temp;
struct sctp_chunk *chunk;
struct sctp_datamsg *msg;
+ struct sctp_sock *sp;
+ struct sctp_af *af;
int err;

msg = sctp_datamsg_new(GFP_KERNEL);
@@ -188,9 +189,12 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
/* This is the biggest possible DATA chunk that can fit into
* the packet
*/
- max_data = asoc->pathmtu -
- sctp_sk(asoc->base.sk)->pf->af->net_header_len -
- sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk);
+ sp = sctp_sk(asoc->base.sk);
+ af = sp->pf->af;
+ max_data = asoc->pathmtu - af->net_header_len -
+ sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk) -
+ af->ip_options_len(asoc->base.sk);
+
max_data = SCTP_TRUNC4(max_data);

/* If the the peer requested that we authenticate DATA chunks
@@ -210,7 +214,6 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,

/* Set first_len and then account for possible bundles on first frag */
first_len = max_data;
-
/* Check to see if we have a pending SACK and try to let it be bundled
* with this message. Do this if we don't have any data queued already.
* To check that, look at out_qlen and retransmit list.
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 51c4887695909d171285b98ce1be779a3adedbab..3baede99a06d17b3f7a0826df4874c9c5af77617 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -423,6 +423,38 @@ static void sctp_v6_copy_addrlist(struct list_head *addrlist,
rcu_read_unlock();
}

+/* Copy over any ip options */
+static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
+{
+ struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
+ struct ipv6_txoptions *opt;
+
+ newnp = inet6_sk(newsk);
+
+ rcu_read_lock();
+ opt = rcu_dereference(np->opt);
+ if (opt)
+ opt = ipv6_dup_options(newsk, opt);
+ RCU_INIT_POINTER(newnp->opt, opt);
+ rcu_read_unlock();
+}
+
+/* Account for the IP options */
+static int sctp_v6_ip_options_len(struct sock *sk)
+{
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct ipv6_txoptions *opt;
+ int len = 0;
+
+ rcu_read_lock();
+ opt = rcu_dereference(np->opt);
+ if (opt)
+ len = opt->opt_flen + opt->opt_nflen;
+
+ rcu_read_unlock();
+ return len;
+}
+
/* Initialize a sockaddr_storage from in incoming skb. */
static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
int is_saddr)
@@ -662,7 +694,6 @@ static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
struct sock *newsk;
struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
struct sctp6_sock *newsctp6sk;
- struct ipv6_txoptions *opt;

newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
if (!newsk)
@@ -685,12 +716,7 @@ static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
newnp->ipv6_ac_list = NULL;
newnp->ipv6_fl_list = NULL;

- rcu_read_lock();
- opt = rcu_dereference(np->opt);
- if (opt)
- opt = ipv6_dup_options(newsk, opt);
- RCU_INIT_POINTER(newnp->opt, opt);
- rcu_read_unlock();
+ sctp_v6_copy_ip_options(sk, newsk);

/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
* and getpeername().
@@ -1033,6 +1059,7 @@ static struct sctp_af sctp_af_inet6 = {
.ecn_capable = sctp_v6_ecn_capable,
.net_header_len = sizeof(struct ipv6hdr),
.sockaddr_len = sizeof(struct sockaddr_in6),
+ .ip_options_len = sctp_v6_ip_options_len,
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_ipv6_setsockopt,
.compat_getsockopt = compat_ipv6_getsockopt,
@@ -1051,6 +1078,7 @@ static struct sctp_pf sctp_pf_inet6 = {
.addr_to_user = sctp_v6_addr_to_user,
.to_sk_saddr = sctp_v6_to_sk_saddr,
.to_sk_daddr = sctp_v6_to_sk_daddr,
+ .copy_ip_options = sctp_v6_copy_ip_options,
.af = &sctp_af_inet6,
};

diff --git a/net/sctp/output.c b/net/sctp/output.c
index 4a865cd06d76cd5b2aa417de618da3203f7b53e4..2b39c704e1e5b99597a2cfdd35f75c78288d943b 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -151,7 +151,10 @@ void sctp_packet_init(struct sctp_packet *packet,
INIT_LIST_HEAD(&packet->chunk_list);
if (asoc) {
struct sctp_sock *sp = sctp_sk(asoc->base.sk);
- overhead = sp->pf->af->net_header_len;
+ struct sctp_af *af = sp->pf->af;
+
+ overhead = af->net_header_len +
+ af->ip_options_len(asoc->base.sk);
} else {
overhead = sizeof(struct ipv6hdr);
}
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index fcd80feb293f61bd734988f037aa8f210880fb1d..cde051a2ed84b4085447b30af5809e2507a69277 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -237,6 +237,38 @@ int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp,
return error;
}

+/* Copy over any ip options */
+static void sctp_v4_copy_ip_options(struct sock *sk, struct sock *newsk)
+{
+ struct inet_sock *newinet, *inet = inet_sk(sk);
+ struct ip_options_rcu *inet_opt, *newopt = NULL;
+
+ newinet = inet_sk(newsk);
+
+ rcu_read_lock();
+ inet_opt = rcu_dereference(inet->inet_opt);
+ if (inet_opt) {
+ newopt = sock_kmalloc(newsk, sizeof(*inet_opt) +
+ inet_opt->opt.optlen, GFP_ATOMIC);
+ if (newopt)
+ memcpy(newopt, inet_opt, sizeof(*inet_opt) +
+ inet_opt->opt.optlen);
+ }
+ RCU_INIT_POINTER(newinet->inet_opt, newopt);
+ rcu_read_unlock();
+}
+
+/* Account for the IP options */
+static int sctp_v4_ip_options_len(struct sock *sk)
+{
+ struct inet_sock *inet = inet_sk(sk);
+
+ if (inet->inet_opt)
+ return inet->inet_opt->opt.optlen;
+ else
+ return 0;
+}
+
/* Initialize a sctp_addr from in incoming skb. */
static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
int is_saddr)
@@ -590,6 +622,8 @@ static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
sctp_copy_sock(newsk, sk, asoc);
sock_reset_flag(newsk, SOCK_ZAPPED);

+ sctp_v4_copy_ip_options(sk, newsk);
+
newinet = inet_sk(newsk);

newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
@@ -1008,6 +1042,7 @@ static struct sctp_pf sctp_pf_inet = {
.addr_to_user = sctp_v4_addr_to_user,
.to_sk_saddr = sctp_v4_to_sk_saddr,
.to_sk_daddr = sctp_v4_to_sk_daddr,
+ .copy_ip_options = sctp_v4_copy_ip_options,
.af = &sctp_af_inet
};

@@ -1092,6 +1127,7 @@ static struct sctp_af sctp_af_inet = {
.ecn_capable = sctp_v4_ecn_capable,
.net_header_len = sizeof(struct iphdr),
.sockaddr_len = sizeof(struct sockaddr_in),
+ .ip_options_len = sctp_v4_ip_options_len,
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_ip_setsockopt,
.compat_getsockopt = compat_ip_getsockopt,
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index d4730ada7f3233367be7a0e3bb10e286a25602c8..274082cf49a8380fda06866c631cdc22dc4f157b 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3125,8 +3125,11 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned

if (asoc) {
if (val == 0) {
+ struct sctp_af *af = sp->pf->af;
+
val = asoc->pathmtu;
- val -= sp->pf->af->net_header_len;
+ val -= af->ip_options_len(asoc->base.sk);
+ val -= af->net_header_len;
val -= sizeof(struct sctphdr) +
sizeof(struct sctp_data_chunk);
}
@@ -4929,9 +4932,11 @@ int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp)
sctp_copy_sock(sock->sk, sk, asoc);

/* Make peeled-off sockets more like 1-1 accepted sockets.
- * Set the daddr and initialize id to something more random
+ * Set the daddr and initialize id to something more random and also
+ * copy over any ip options.
*/
sp->pf->to_sk_daddr(&asoc->peer.primary_addr, sk);
+ sp->pf->copy_ip_options(sk, sock->sk);

/* Populate the fields of the newsk from the oldsk and migrate the
* asoc to the newsk.
--
2.14.3
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