AppArmor: basic auditing infrastructure.
John Johansen [Thu, 29 Jul 2010 21:47:58 +0000 (14:47 -0700)]
Update lsm_audit for AppArmor specific data, and add the core routines for
AppArmor uses for auditing.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>

include/linux/lsm_audit.h
security/apparmor/audit.c [new file with mode: 0644]
security/apparmor/include/audit.h [new file with mode: 0644]

index 788f0ab..112a550 100644 (file)
@@ -99,6 +99,33 @@ struct common_audit_data {
                        int result;
                } selinux_audit_data;
 #endif
+#ifdef CONFIG_SECURITY_APPARMOR
+               struct {
+                       int error;
+                       int op;
+                       int type;
+                       void *profile;
+                       const char *name;
+                       const char *info;
+                       union {
+                               void *target;
+                               struct {
+                                       long pos;
+                                       void *target;
+                               } iface;
+                               struct {
+                                       int rlim;
+                                       unsigned long max;
+                               } rlim;
+                               struct {
+                                       const char *target;
+                                       u32 request;
+                                       u32 denied;
+                                       uid_t ouid;
+                               } fs;
+                       };
+               } apparmor_audit_data;
+#endif
        };
        /* these callback will be implemented by a specific LSM */
        void (*lsm_pre_audit)(struct audit_buffer *, void *);
diff --git a/security/apparmor/audit.c b/security/apparmor/audit.c
new file mode 100644 (file)
index 0000000..96502b2
--- /dev/null
@@ -0,0 +1,215 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor auditing functions
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2010 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 <linux/audit.h>
+#include <linux/socket.h>
+
+#include "include/apparmor.h"
+#include "include/audit.h"
+#include "include/policy.h"
+
+const char *op_table[] = {
+       "null",
+
+       "sysctl",
+       "capable",
+
+       "unlink",
+       "mkdir",
+       "rmdir",
+       "mknod",
+       "truncate",
+       "link",
+       "symlink",
+       "rename_src",
+       "rename_dest",
+       "chmod",
+       "chown",
+       "getattr",
+       "open",
+
+       "file_perm",
+       "file_lock",
+       "file_mmap",
+       "file_mprotect",
+
+       "create",
+       "post_create",
+       "bind",
+       "connect",
+       "listen",
+       "accept",
+       "sendmsg",
+       "recvmsg",
+       "getsockname",
+       "getpeername",
+       "getsockopt",
+       "setsockopt",
+       "socket_shutdown",
+
+       "ptrace",
+
+       "exec",
+       "change_hat",
+       "change_profile",
+       "change_onexec",
+
+       "setprocattr",
+       "setrlimit",
+
+       "profile_replace",
+       "profile_load",
+       "profile_remove"
+};
+
+const char *audit_mode_names[] = {
+       "normal",
+       "quiet_denied",
+       "quiet",
+       "noquiet",
+       "all"
+};
+
+static char *aa_audit_type[] = {
+       "AUDIT",
+       "ALLOWED",
+       "DENIED",
+       "HINT",
+       "STATUS",
+       "ERROR",
+       "KILLED"
+};
+
+/*
+ * Currently AppArmor auditing is fed straight into the audit framework.
+ *
+ * TODO:
+ * netlink interface for complain mode
+ * user auditing, - send user auditing to netlink interface
+ * system control of whether user audit messages go to system log
+ */
+
+/**
+ * audit_base - core AppArmor function.
+ * @ab: audit buffer to fill (NOT NULL)
+ * @ca: audit structure containing data to audit (NOT NULL)
+ *
+ * Record common AppArmor audit data from @sa
+ */
+static void audit_pre(struct audit_buffer *ab, void *ca)
+{
+       struct common_audit_data *sa = ca;
+       struct task_struct *tsk = sa->tsk ? sa->tsk : current;
+
+       if (aa_g_audit_header) {
+               audit_log_format(ab, "apparmor=");
+               audit_log_string(ab, aa_audit_type[sa->aad.type]);
+       }
+
+       if (sa->aad.op) {
+               audit_log_format(ab, " operation=");
+               audit_log_string(ab, op_table[sa->aad.op]);
+       }
+
+       if (sa->aad.info) {
+               audit_log_format(ab, " info=");
+               audit_log_string(ab, sa->aad.info);
+               if (sa->aad.error)
+                       audit_log_format(ab, " error=%d", sa->aad.error);
+       }
+
+       if (sa->aad.profile) {
+               struct aa_profile *profile = sa->aad.profile;
+               pid_t pid;
+               rcu_read_lock();
+               pid = tsk->real_parent->pid;
+               rcu_read_unlock();
+               audit_log_format(ab, " parent=%d", pid);
+               if (profile->ns != root_ns) {
+                       audit_log_format(ab, " namespace=");
+                       audit_log_untrustedstring(ab, profile->ns->base.hname);
+               }
+               audit_log_format(ab, " profile=");
+               audit_log_untrustedstring(ab, profile->base.hname);
+       }
+
+       if (sa->aad.name) {
+               audit_log_format(ab, " name=");
+               audit_log_untrustedstring(ab, sa->aad.name);
+       }
+}
+
+/**
+ * aa_audit_msg - Log a message to the audit subsystem
+ * @sa: audit event structure (NOT NULL)
+ * @cb: optional callback fn for type specific fields (MAYBE NULL)
+ */
+void aa_audit_msg(int type, struct common_audit_data *sa,
+                 void (*cb) (struct audit_buffer *, void *))
+{
+       sa->aad.type = type;
+       sa->lsm_pre_audit = audit_pre;
+       sa->lsm_post_audit = cb;
+       common_lsm_audit(sa);
+}
+
+/**
+ * aa_audit - Log a profile based audit event to the audit subsystem
+ * @type: audit type for the message
+ * @profile: profile to check against (NOT NULL)
+ * @gfp: allocation flags to use
+ * @sa: audit event (NOT NULL)
+ * @cb: optional callback fn for type specific fields (MAYBE NULL)
+ *
+ * Handle default message switching based off of audit mode flags
+ *
+ * Returns: error on failure
+ */
+int aa_audit(int type, struct aa_profile *profile, gfp_t gfp,
+            struct common_audit_data *sa,
+            void (*cb) (struct audit_buffer *, void *))
+{
+       BUG_ON(!profile);
+
+       if (type == AUDIT_APPARMOR_AUTO) {
+               if (likely(!sa->aad.error)) {
+                       if (AUDIT_MODE(profile) != AUDIT_ALL)
+                               return 0;
+                       type = AUDIT_APPARMOR_AUDIT;
+               } else if (COMPLAIN_MODE(profile))
+                       type = AUDIT_APPARMOR_ALLOWED;
+               else
+                       type = AUDIT_APPARMOR_DENIED;
+       }
+       if (AUDIT_MODE(profile) == AUDIT_QUIET ||
+           (type == AUDIT_APPARMOR_DENIED &&
+            AUDIT_MODE(profile) == AUDIT_QUIET))
+               return sa->aad.error;
+
+       if (KILL_MODE(profile) && type == AUDIT_APPARMOR_DENIED)
+               type = AUDIT_APPARMOR_KILL;
+
+       if (!unconfined(profile))
+               sa->aad.profile = profile;
+
+       aa_audit_msg(type, sa, cb);
+
+       if (sa->aad.type == AUDIT_APPARMOR_KILL)
+               (void)send_sig_info(SIGKILL, NULL, sa->tsk ? sa->tsk : current);
+
+       if (sa->aad.type == AUDIT_APPARMOR_ALLOWED)
+               return complain_error(sa->aad.error);
+
+       return sa->aad.error;
+}
diff --git a/security/apparmor/include/audit.h b/security/apparmor/include/audit.h
new file mode 100644 (file)
index 0000000..1951786
--- /dev/null
@@ -0,0 +1,123 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor auditing function definitions.
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2010 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_AUDIT_H
+#define __AA_AUDIT_H
+
+#include <linux/audit.h>
+#include <linux/fs.h>
+#include <linux/lsm_audit.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include "file.h"
+
+struct aa_profile;
+
+extern const char *audit_mode_names[];
+#define AUDIT_MAX_INDEX 5
+
+#define AUDIT_APPARMOR_AUTO 0  /* auto choose audit message type */
+
+enum audit_mode {
+       AUDIT_NORMAL,           /* follow normal auditing of accesses */
+       AUDIT_QUIET_DENIED,     /* quiet all denied access messages */
+       AUDIT_QUIET,            /* quiet all messages */
+       AUDIT_NOQUIET,          /* do not quiet audit messages */
+       AUDIT_ALL               /* audit all accesses */
+};
+
+enum audit_type {
+       AUDIT_APPARMOR_AUDIT,
+       AUDIT_APPARMOR_ALLOWED,
+       AUDIT_APPARMOR_DENIED,
+       AUDIT_APPARMOR_HINT,
+       AUDIT_APPARMOR_STATUS,
+       AUDIT_APPARMOR_ERROR,
+       AUDIT_APPARMOR_KILL
+};
+
+extern const char *op_table[];
+enum aa_ops {
+       OP_NULL,
+
+       OP_SYSCTL,
+       OP_CAPABLE,
+
+       OP_UNLINK,
+       OP_MKDIR,
+       OP_RMDIR,
+       OP_MKNOD,
+       OP_TRUNC,
+       OP_LINK,
+       OP_SYMLINK,
+       OP_RENAME_SRC,
+       OP_RENAME_DEST,
+       OP_CHMOD,
+       OP_CHOWN,
+       OP_GETATTR,
+       OP_OPEN,
+
+       OP_FPERM,
+       OP_FLOCK,
+       OP_FMMAP,
+       OP_FMPROT,
+
+       OP_CREATE,
+       OP_POST_CREATE,
+       OP_BIND,
+       OP_CONNECT,
+       OP_LISTEN,
+       OP_ACCEPT,
+       OP_SENDMSG,
+       OP_RECVMSG,
+       OP_GETSOCKNAME,
+       OP_GETPEERNAME,
+       OP_GETSOCKOPT,
+       OP_SETSOCKOPT,
+       OP_SOCK_SHUTDOWN,
+
+       OP_PTRACE,
+
+       OP_EXEC,
+       OP_CHANGE_HAT,
+       OP_CHANGE_PROFILE,
+       OP_CHANGE_ONEXEC,
+
+       OP_SETPROCATTR,
+       OP_SETRLIMIT,
+
+       OP_PROF_REPL,
+       OP_PROF_LOAD,
+       OP_PROF_RM,
+};
+
+
+/* define a short hand for apparmor_audit_data portion of common_audit_data */
+#define aad apparmor_audit_data
+
+void aa_audit_msg(int type, struct common_audit_data *sa,
+                 void (*cb) (struct audit_buffer *, void *));
+int aa_audit(int type, struct aa_profile *profile, gfp_t gfp,
+            struct common_audit_data *sa,
+            void (*cb) (struct audit_buffer *, void *));
+
+static inline int complain_error(int error)
+{
+       if (error == -EPERM || error == -EACCES)
+               return 0;
+       return error;
+}
+
+#endif /* __AA_AUDIT_H */