Patchwork [3/5] UBUNTU: SAUCE: AppArmor: basic networking rules

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Submitter John Johansen
Date May 22, 2012, 3:22 p.m.
Message ID <1337700142-13370-4-git-send-email-john.johansen@canonical.com>
Download mbox | patch
Permalink /patch/160663/
State New
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John Johansen - May 22, 2012, 3:22 p.m.
Base support for network mediation.

Signed-off-by: John Johansen <john.johansen@canonical.com>
---
 security/apparmor/.gitignore       |    2 +-
 security/apparmor/Makefile         |   42 +++++++++-
 security/apparmor/apparmorfs.c     |    1 +
 security/apparmor/include/audit.h  |    4 +
 security/apparmor/include/net.h    |   44 ++++++++++
 security/apparmor/include/policy.h |    3 +
 security/apparmor/lsm.c            |  112 +++++++++++++++++++++++++
 security/apparmor/net.c            |  162 ++++++++++++++++++++++++++++++++++++
 security/apparmor/policy.c         |    1 +
 security/apparmor/policy_unpack.c  |   46 ++++++++++
 10 files changed, 414 insertions(+), 3 deletions(-)
 create mode 100644 security/apparmor/include/net.h
 create mode 100644 security/apparmor/net.c

Patch

diff --git a/security/apparmor/.gitignore b/security/apparmor/.gitignore
index 4d995ae..d5b291e 100644
--- a/security/apparmor/.gitignore
+++ b/security/apparmor/.gitignore
@@ -1,6 +1,6 @@ 
 #
 # Generated include files
 #
-af_names.h
+net_names.h
 capability_names.h
 rlim_names.h
diff --git a/security/apparmor/Makefile b/security/apparmor/Makefile
index f6c51c0..c575af9 100644
--- a/security/apparmor/Makefile
+++ b/security/apparmor/Makefile
@@ -4,9 +4,9 @@  obj-$(CONFIG_SECURITY_APPARMOR) += apparmor.o
 
 apparmor-y := apparmorfs.o audit.o capability.o context.o ipc.o lib.o match.o \
               path.o domain.o policy.o policy_unpack.o procattr.o lsm.o \
-              resource.o sid.o file.o mount.o
+              resource.o sid.o file.o mount.o net.o
 
-clean-files := capability_names.h rlim_names.h
+clean-files := capability_names.h rlim_names.h net_names.h
 
 # Build a lower case string table of capability names
 # Transforms lines from
@@ -19,6 +19,38 @@  cmd_make-caps = echo "static const char *const capability_names[] = {" > $@ ;\
 	-e 's/^\#define[ \t]+CAP_([A-Z0-9_]+)[ \t]+([0-9]+)/[\2] = "\L\1",/p';\
 	echo "};" >> $@
 
+# Build a lower case string table of address family names
+# Transform lines from
+#    define AF_LOCAL	1	/* POSIX name for AF_UNIX	*/
+#    #define AF_INET		2	/* Internet IP Protocol 	*/
+# to
+#    [1] = "local",
+#    [2] = "inet",
+#
+# and build the securityfs entries for the mapping.
+# Transforms lines from
+#    #define AF_INET		2	/* Internet IP Protocol 	*/
+# to
+#    #define AA_FS_AF_MASK "local inet"
+quiet_cmd_make-af = GEN     $@
+cmd_make-af = echo "static const char *address_family_names[] = {" > $@ ;\
+	sed $< >>$@ -r -n -e "/AF_MAX/d" -e "/AF_LOCAL/d" -e \
+	 's/^\#define[ \t]+AF_([A-Z0-9_]+)[ \t]+([0-9]+)(.*)/[\2] = "\L\1",/p';\
+	echo "};" >> $@ ;\
+	echo -n '\#define AA_FS_AF_MASK "' >> $@ ;\
+	sed -r -n 's/^\#define[ \t]+AF_([A-Z0-9_]+)[ \t]+([0-9]+)(.*)/\L\1/p'\
+	 $< | tr '\n' ' ' | sed -e 's/ $$/"\n/' >> $@
+
+# Build a lower case string table of sock type names
+# Transform lines from
+#    SOCK_STREAM	= 1,
+# to
+#    [1] = "stream",
+quiet_cmd_make-sock = GEN     $@
+cmd_make-sock = echo "static const char *sock_type_names[] = {" >> $@ ;\
+	sed $^ >>$@ -r -n \
+	-e 's/^\tSOCK_([A-Z0-9_]+)[\t]+=[ \t]+([0-9]+)(.*)/[\2] = "\L\1",/p';\
+	echo "};" >> $@
 
 # Build a lower case string table of rlimit names.
 # Transforms lines from
@@ -55,6 +87,7 @@  cmd_make-rlim = echo "static const char *const rlim_names[RLIM_NLIMITS] = {" \
 	    tr '\n' ' ' | sed -e 's/ $$/"\n/' >> $@
 
 $(obj)/capability.o : $(obj)/capability_names.h
+$(obj)/net.o : $(obj)/net_names.h
 $(obj)/resource.o : $(obj)/rlim_names.h
 $(obj)/capability_names.h : $(srctree)/include/linux/capability.h \
 			    $(src)/Makefile
@@ -62,3 +95,8 @@  $(obj)/capability_names.h : $(srctree)/include/linux/capability.h \
 $(obj)/rlim_names.h : $(srctree)/include/asm-generic/resource.h \
 		      $(src)/Makefile
 	$(call cmd,make-rlim)
+$(obj)/net_names.h : $(srctree)/include/linux/socket.h \
+		     $(srctree)/include/linux/net.h \
+		     $(src)/Makefile
+	$(call cmd,make-af)
+	$(call cmd,make-sock)
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index fbedacb..01a335d 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -438,6 +438,7 @@  static struct aa_fs_entry aa_fs_entry_namespaces[] = {
 static struct aa_fs_entry aa_fs_entry_features[] = {
 	AA_FS_DIR("domain",			aa_fs_entry_domain),
 	AA_FS_DIR("file",			aa_fs_entry_file),
+	AA_FS_DIR("network",                    aa_fs_entry_network),
 	AA_FS_DIR("mount",			aa_fs_entry_mount),
 	AA_FS_DIR("namespaces",			aa_fs_entry_namespaces),
 	AA_FS_FILE_U64("capability",		VFS_CAP_FLAGS_MASK),
diff --git a/security/apparmor/include/audit.h b/security/apparmor/include/audit.h
index 0a04152..7b90900c 100644
--- a/security/apparmor/include/audit.h
+++ b/security/apparmor/include/audit.h
@@ -137,6 +137,10 @@  struct apparmor_audit_data {
 			u32 denied;
 			uid_t ouid;
 		} fs;
+		struct {
+			int type, protocol;
+			struct sock *sk;
+		} net;
 	};
 };
 
diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h
new file mode 100644
index 0000000..cb8a121
--- /dev/null
+++ b/security/apparmor/include/net.h
@@ -0,0 +1,44 @@ 
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor network mediation definitions.
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2012 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ */
+
+#ifndef __AA_NET_H
+#define __AA_NET_H
+
+#include <net/sock.h>
+
+#include "apparmorfs.h"
+
+/* struct aa_net - network confinement data
+ * @allowed: basic network families permissions
+ * @audit_network: which network permissions to force audit
+ * @quiet_network: which network permissions to quiet rejects
+ */
+struct aa_net {
+	u16 allow[AF_MAX];
+	u16 audit[AF_MAX];
+	u16 quiet[AF_MAX];
+};
+
+extern struct aa_fs_entry aa_fs_entry_network[];
+
+extern int aa_net_perm(int op, struct aa_profile *profile, u16 family,
+		       int type, int protocol, struct sock *sk);
+extern int aa_revalidate_sk(int op, struct sock *sk);
+
+static inline void aa_free_net_rules(struct aa_net *new)
+{
+	/* NOP */
+}
+
+#endif /* __AA_NET_H */
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h
index bda4569..eb13a73 100644
--- a/security/apparmor/include/policy.h
+++ b/security/apparmor/include/policy.h
@@ -27,6 +27,7 @@ 
 #include "capability.h"
 #include "domain.h"
 #include "file.h"
+#include "net.h"
 #include "resource.h"
 
 extern const char *const profile_mode_names[];
@@ -157,6 +158,7 @@  struct aa_policydb {
  * @policy: general match rules governing policy
  * @file: The set of rules governing basic file access and domain transitions
  * @caps: capabilities for the profile
+ * @net: network controls for the profile
  * @rlimits: rlimits for the profile
  *
  * The AppArmor profile contains the basic confinement data.  Each profile
@@ -194,6 +196,7 @@  struct aa_profile {
 	struct aa_policydb policy;
 	struct aa_file_rules file;
 	struct aa_caps caps;
+	struct aa_net net;
 	struct aa_rlimit rlimits;
 };
 
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 4ef0211..4512cc6 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -32,6 +32,7 @@ 
 #include "include/context.h"
 #include "include/file.h"
 #include "include/ipc.h"
+#include "include/net.h"
 #include "include/path.h"
 #include "include/policy.h"
 #include "include/procattr.h"
@@ -677,6 +678,104 @@  static int apparmor_task_setrlimit(struct task_struct *task,
 	return error;
 }
 
+static int apparmor_socket_create(int family, int type, int protocol, int kern)
+{
+	struct aa_profile *profile;
+	int error = 0;
+
+	if (kern)
+		return 0;
+
+	profile = __aa_current_profile();
+	if (!unconfined(profile))
+		error = aa_net_perm(OP_CREATE, profile, family, type, protocol,
+				    NULL);
+	return error;
+}
+
+static int apparmor_socket_bind(struct socket *sock,
+				struct sockaddr *address, int addrlen)
+{
+	struct sock *sk = sock->sk;
+
+	return aa_revalidate_sk(OP_BIND, sk);
+}
+
+static int apparmor_socket_connect(struct socket *sock,
+				   struct sockaddr *address, int addrlen)
+{
+	struct sock *sk = sock->sk;
+
+	return aa_revalidate_sk(OP_CONNECT, sk);
+}
+
+static int apparmor_socket_listen(struct socket *sock, int backlog)
+{
+	struct sock *sk = sock->sk;
+
+	return aa_revalidate_sk(OP_LISTEN, sk);
+}
+
+static int apparmor_socket_accept(struct socket *sock, struct socket *newsock)
+{
+	struct sock *sk = sock->sk;
+
+	return aa_revalidate_sk(OP_ACCEPT, sk);
+}
+
+static int apparmor_socket_sendmsg(struct socket *sock,
+				   struct msghdr *msg, int size)
+{
+	struct sock *sk = sock->sk;
+
+	return aa_revalidate_sk(OP_SENDMSG, sk);
+}
+
+static int apparmor_socket_recvmsg(struct socket *sock,
+				   struct msghdr *msg, int size, int flags)
+{
+	struct sock *sk = sock->sk;
+
+	return aa_revalidate_sk(OP_RECVMSG, sk);
+}
+
+static int apparmor_socket_getsockname(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+
+	return aa_revalidate_sk(OP_GETSOCKNAME, sk);
+}
+
+static int apparmor_socket_getpeername(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+
+	return aa_revalidate_sk(OP_GETPEERNAME, sk);
+}
+
+static int apparmor_socket_getsockopt(struct socket *sock, int level,
+				      int optname)
+{
+	struct sock *sk = sock->sk;
+
+	return aa_revalidate_sk(OP_GETSOCKOPT, sk);
+}
+
+static int apparmor_socket_setsockopt(struct socket *sock, int level,
+				      int optname)
+{
+	struct sock *sk = sock->sk;
+
+	return aa_revalidate_sk(OP_SETSOCKOPT, sk);
+}
+
+static int apparmor_socket_shutdown(struct socket *sock, int how)
+{
+	struct sock *sk = sock->sk;
+
+	return aa_revalidate_sk(OP_SOCK_SHUTDOWN, sk);
+}
+
 static struct security_operations apparmor_ops = {
 	.name =				"apparmor",
 
@@ -712,6 +811,19 @@  static struct security_operations apparmor_ops = {
 	.getprocattr =			apparmor_getprocattr,
 	.setprocattr =			apparmor_setprocattr,
 
+	.socket_create =		apparmor_socket_create,
+	.socket_bind =			apparmor_socket_bind,
+	.socket_connect =		apparmor_socket_connect,
+	.socket_listen =		apparmor_socket_listen,
+	.socket_accept =		apparmor_socket_accept,
+	.socket_sendmsg =		apparmor_socket_sendmsg,
+	.socket_recvmsg =		apparmor_socket_recvmsg,
+	.socket_getsockname =		apparmor_socket_getsockname,
+	.socket_getpeername =		apparmor_socket_getpeername,
+	.socket_getsockopt =		apparmor_socket_getsockopt,
+	.socket_setsockopt =		apparmor_socket_setsockopt,
+	.socket_shutdown =		apparmor_socket_shutdown,
+
 	.cred_alloc_blank =		apparmor_cred_alloc_blank,
 	.cred_free =			apparmor_cred_free,
 	.cred_prepare =			apparmor_cred_prepare,
diff --git a/security/apparmor/net.c b/security/apparmor/net.c
new file mode 100644
index 0000000..084232b
--- /dev/null
+++ b/security/apparmor/net.c
@@ -0,0 +1,162 @@ 
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor network mediation
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2012 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ */
+
+#include "include/apparmor.h"
+#include "include/audit.h"
+#include "include/context.h"
+#include "include/net.h"
+#include "include/policy.h"
+
+#include "net_names.h"
+
+struct aa_fs_entry aa_fs_entry_network[] = {
+	AA_FS_FILE_STRING("af_mask", AA_FS_AF_MASK),
+	{ }
+};
+
+/* audit callback for net specific fields */
+static void audit_cb(struct audit_buffer *ab, void *va)
+{
+	struct common_audit_data *sa = va;
+
+	audit_log_format(ab, " family=");
+	if (address_family_names[sa->u.net->family]) {
+		audit_log_string(ab, address_family_names[sa->u.net->family]);
+	} else {
+		audit_log_format(ab, "\"unknown(%d)\"", sa->u.net->family);
+	}
+	audit_log_format(ab, " sock_type=");
+	if (sock_type_names[sa->aad->net.type]) {
+		audit_log_string(ab, sock_type_names[sa->aad->net.type]);
+	} else {
+		audit_log_format(ab, "\"unknown(%d)\"", sa->aad->net.type);
+	}
+	audit_log_format(ab, " protocol=%d", sa->aad->net.protocol);
+}
+
+/**
+ * audit_net - audit network access
+ * @profile: profile being enforced  (NOT NULL)
+ * @op: operation being checked
+ * @family: network family
+ * @type:   network type
+ * @protocol: network protocol
+ * @sk: socket auditing is being applied to
+ * @error: error code for failure else 0
+ *
+ * Returns: %0 or sa->error else other errorcode on failure
+ */
+static int audit_net(struct aa_profile *profile, int op, u16 family, int type,
+		     int protocol, struct sock *sk, int error)
+{
+	int audit_type = AUDIT_APPARMOR_AUTO;
+	struct common_audit_data sa;
+	struct apparmor_audit_data aad = { };
+	struct lsm_network_audit net = { };
+	if (sk) {
+		COMMON_AUDIT_DATA_INIT(&sa, NET);
+	} else {
+		COMMON_AUDIT_DATA_INIT(&sa, NONE);
+	}
+	/* todo fill in socket addr info */
+	sa.aad = &aad;
+	sa.u.net = &net;
+	sa.aad->op = op,
+	sa.u.net->family = family;
+	sa.u.net->sk = sk;
+	sa.aad->net.type = type;
+	sa.aad->net.protocol = protocol;
+	sa.aad->error = error;
+
+	if (likely(!sa.aad->error)) {
+		u16 audit_mask = profile->net.audit[sa.u.net->family];
+		if (likely((AUDIT_MODE(profile) != AUDIT_ALL) &&
+			   !(1 << sa.aad->net.type & audit_mask)))
+			return 0;
+		audit_type = AUDIT_APPARMOR_AUDIT;
+	} else {
+		u16 quiet_mask = profile->net.quiet[sa.u.net->family];
+		u16 kill_mask = 0;
+		u16 denied = (1 << sa.aad->net.type) & ~quiet_mask;
+
+		if (denied & kill_mask)
+			audit_type = AUDIT_APPARMOR_KILL;
+
+		if ((denied & quiet_mask) &&
+		    AUDIT_MODE(profile) != AUDIT_NOQUIET &&
+		    AUDIT_MODE(profile) != AUDIT_ALL)
+			return COMPLAIN_MODE(profile) ? 0 : sa.aad->error;
+	}
+
+	return aa_audit(audit_type, profile, GFP_KERNEL, &sa, audit_cb);
+}
+
+/**
+ * aa_net_perm - very course network access check
+ * @op: operation being checked
+ * @profile: profile being enforced  (NOT NULL)
+ * @family: network family
+ * @type:   network type
+ * @protocol: network protocol
+ *
+ * Returns: %0 else error if permission denied
+ */
+int aa_net_perm(int op, struct aa_profile *profile, u16 family, int type,
+		int protocol, struct sock *sk)
+{
+	u16 family_mask;
+	int error;
+
+	if ((family < 0) || (family >= AF_MAX))
+		return -EINVAL;
+
+	if ((type < 0) || (type >= SOCK_MAX))
+		return -EINVAL;
+
+	/* unix domain and netlink sockets are handled by ipc */
+	if (family == AF_UNIX || family == AF_NETLINK)
+		return 0;
+
+	family_mask = profile->net.allow[family];
+
+	error = (family_mask & (1 << type)) ? 0 : -EACCES;
+
+	return audit_net(profile, op, family, type, protocol, sk, error);
+}
+
+/**
+ * aa_revalidate_sk - Revalidate access to a sock
+ * @op: operation being checked
+ * @sk: sock being revalidated  (NOT NULL)
+ *
+ * Returns: %0 else error if permission denied
+ */
+int aa_revalidate_sk(int op, struct sock *sk)
+{
+	struct aa_profile *profile;
+	int error = 0;
+
+	/* aa_revalidate_sk should not be called from interrupt context
+	 * don't mediate these calls as they are not task related
+	 */
+	if (in_interrupt())
+		return 0;
+
+	profile = __aa_current_profile();
+	if (!unconfined(profile))
+		error = aa_net_perm(op, profile, sk->sk_family, sk->sk_type,
+				    sk->sk_protocol, sk);
+
+	return error;
+}
diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c
index f1f7506..b8100a7 100644
--- a/security/apparmor/policy.c
+++ b/security/apparmor/policy.c
@@ -745,6 +745,7 @@  static void free_profile(struct aa_profile *profile)
 
 	aa_free_file_rules(&profile->file);
 	aa_free_cap_rules(&profile->caps);
+	aa_free_net_rules(&profile->net);
 	aa_free_rlimit_rules(&profile->rlimits);
 
 	aa_free_sid(profile->sid);
diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
index deab7c7..8f8e9c1 100644
--- a/security/apparmor/policy_unpack.c
+++ b/security/apparmor/policy_unpack.c
@@ -193,6 +193,19 @@  fail:
 	return 0;
 }
 
+static bool unpack_u16(struct aa_ext *e, u16 *data, const char *name)
+{
+	if (unpack_nameX(e, AA_U16, name)) {
+		if (!inbounds(e, sizeof(u16)))
+			return 0;
+		if (data)
+			*data = le16_to_cpu(get_unaligned((u16 *) e->pos));
+		e->pos += sizeof(u16);
+		return 1;
+	}
+	return 0;
+}
+
 static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
 {
 	if (unpack_nameX(e, AA_U32, name)) {
@@ -471,6 +484,7 @@  static struct aa_profile *unpack_profile(struct aa_ext *e)
 {
 	struct aa_profile *profile = NULL;
 	const char *name = NULL;
+	size_t size = 0;
 	int i, error = -EPROTO;
 	kernel_cap_t tmpcap;
 	u32 tmp;
@@ -564,6 +578,38 @@  static struct aa_profile *unpack_profile(struct aa_ext *e)
 	if (!unpack_rlimits(e, profile))
 		goto fail;
 
+	size = unpack_array(e, "net_allowed_af");
+	if (size) {
+
+		for (i = 0; i < size; i++) {
+			/* discard extraneous rules that this kernel will
+			 * never request
+			 */
+			if (i >= AF_MAX) {
+				u16 tmp;
+				if (!unpack_u16(e, &tmp, NULL) ||
+				    !unpack_u16(e, &tmp, NULL) ||
+				    !unpack_u16(e, &tmp, NULL))
+					goto fail;
+				continue;
+			}
+			if (!unpack_u16(e, &profile->net.allow[i], NULL))
+				goto fail;
+			if (!unpack_u16(e, &profile->net.audit[i], NULL))
+				goto fail;
+			if (!unpack_u16(e, &profile->net.quiet[i], NULL))
+				goto fail;
+		}
+		if (!unpack_nameX(e, AA_ARRAYEND, NULL))
+			goto fail;
+	}
+	/*
+	 * allow unix domain and netlink sockets they are handled
+	 * by IPC
+	 */
+	profile->net.allow[AF_UNIX] = 0xffff;
+	profile->net.allow[AF_NETLINK] = 0xffff;
+
 	if (unpack_nameX(e, AA_STRUCT, "policydb")) {
 		/* generic policy dfa - optional and may be NULL */
 		profile->policy.dfa = unpack_dfa(e);