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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2011-06-26 23:18:58 +0900
committerJames Morris <jmorris@namei.org>2011-06-29 09:31:20 +1000
commiteadd99cc85347b4f9eb10122ac90032eb4971b02 (patch)
treefa6075ad4917422288222ee52bfcb66b7ed30a0e /security/tomoyo/audit.c
parentd5ca1725ac9ba876c2dd614bb9826d0c4e13d818 (diff)
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TOMOYO: Add auditing interface.
Add /sys/kernel/security/tomoyo/audit interface. This interface generates audit logs in the form of domain policy so that /usr/sbin/tomoyo-auditd can reuse audit logs for appending to /sys/kernel/security/tomoyo/domain_policy interface. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security/tomoyo/audit.c')
-rw-r--r--security/tomoyo/audit.c300
1 files changed, 300 insertions, 0 deletions
diff --git a/security/tomoyo/audit.c b/security/tomoyo/audit.c
new file mode 100644
index 00000000000..e882f17065f
--- /dev/null
+++ b/security/tomoyo/audit.c
@@ -0,0 +1,300 @@
+/*
+ * security/tomoyo/audit.c
+ *
+ * Pathname restriction functions.
+ *
+ * Copyright (C) 2005-2010 NTT DATA CORPORATION
+ */
+
+#include "common.h"
+#include <linux/slab.h>
+
+/**
+ * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
+ *
+ * @time: Seconds since 1970/01/01 00:00:00.
+ * @stamp: Pointer to "struct tomoyo_time".
+ *
+ * Returns nothing.
+ *
+ * This function does not handle Y2038 problem.
+ */
+static void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp)
+{
+ static const u16 tomoyo_eom[2][12] = {
+ { 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
+ { 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
+ };
+ u16 y;
+ u8 m;
+ bool r;
+ stamp->sec = time % 60;
+ time /= 60;
+ stamp->min = time % 60;
+ time /= 60;
+ stamp->hour = time % 24;
+ time /= 24;
+ for (y = 1970; ; y++) {
+ const unsigned short days = (y & 3) ? 365 : 366;
+ if (time < days)
+ break;
+ time -= days;
+ }
+ r = (y & 3) == 0;
+ for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++)
+ ;
+ if (m)
+ time -= tomoyo_eom[r][m - 1];
+ stamp->year = y;
+ stamp->month = ++m;
+ stamp->day = ++time;
+}
+
+/**
+ * tomoyo_print_header - Get header line of audit log.
+ *
+ * @r: Pointer to "struct tomoyo_request_info".
+ *
+ * Returns string representation.
+ *
+ * This function uses kmalloc(), so caller must kfree() if this function
+ * didn't return NULL.
+ */
+static char *tomoyo_print_header(struct tomoyo_request_info *r)
+{
+ struct tomoyo_time stamp;
+ const pid_t gpid = task_pid_nr(current);
+ static const int tomoyo_buffer_len = 4096;
+ char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
+ pid_t ppid;
+ if (!buffer)
+ return NULL;
+ {
+ struct timeval tv;
+ do_gettimeofday(&tv);
+ tomoyo_convert_time(tv.tv_sec, &stamp);
+ }
+ rcu_read_lock();
+ ppid = task_tgid_vnr(current->real_parent);
+ rcu_read_unlock();
+ snprintf(buffer, tomoyo_buffer_len - 1,
+ "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s "
+ "granted=%s (global-pid=%u) task={ pid=%u ppid=%u "
+ "uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u "
+ "fsuid=%u fsgid=%u }",
+ stamp.year, stamp.month, stamp.day, stamp.hour,
+ stamp.min, stamp.sec, r->profile, tomoyo_mode[r->mode],
+ tomoyo_yesno(r->granted), gpid, task_tgid_vnr(current), ppid,
+ current_uid(), current_gid(), current_euid(), current_egid(),
+ current_suid(), current_sgid(), current_fsuid(),
+ current_fsgid());
+ return buffer;
+}
+
+/**
+ * tomoyo_init_log - Allocate buffer for audit logs.
+ *
+ * @r: Pointer to "struct tomoyo_request_info".
+ * @len: Buffer size needed for @fmt and @args.
+ * @fmt: The printf()'s format string.
+ * @args: va_list structure for @fmt.
+ *
+ * Returns pointer to allocated memory.
+ *
+ * This function uses kzalloc(), so caller must kfree() if this function
+ * didn't return NULL.
+ */
+char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
+ va_list args)
+{
+ char *buf = NULL;
+ const char *header = NULL;
+ int pos;
+ const char *domainname = tomoyo_domain()->domainname->name;
+ header = tomoyo_print_header(r);
+ if (!header)
+ return NULL;
+ /* +10 is for '\n' etc. and '\0'. */
+ len += strlen(domainname) + strlen(header) + 10;
+ len = tomoyo_round2(len);
+ buf = kzalloc(len, GFP_NOFS);
+ if (!buf)
+ goto out;
+ len--;
+ pos = snprintf(buf, len, "%s", header);
+ pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
+ vsnprintf(buf + pos, len - pos, fmt, args);
+out:
+ kfree(header);
+ return buf;
+}
+
+/* Wait queue for /sys/kernel/security/tomoyo/audit. */
+static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait);
+
+/* Structure for audit log. */
+struct tomoyo_log {
+ struct list_head list;
+ char *log;
+ int size;
+};
+
+/* The list for "struct tomoyo_log". */
+static LIST_HEAD(tomoyo_log);
+
+/* Lock for "struct list_head tomoyo_log". */
+static DEFINE_SPINLOCK(tomoyo_log_lock);
+
+/* Length of "stuct list_head tomoyo_log". */
+static unsigned int tomoyo_log_count;
+
+/**
+ * tomoyo_get_audit - Get audit mode.
+ *
+ * @profile: Profile number.
+ * @index: Index number of functionality.
+ * @is_granted: True if granted log, false otherwise.
+ *
+ * Returns true if this request should be audited, false otherwise.
+ */
+static bool tomoyo_get_audit(const u8 profile, const u8 index,
+ const bool is_granted)
+{
+ u8 mode;
+ const u8 category = TOMOYO_MAC_CATEGORY_FILE + TOMOYO_MAX_MAC_INDEX;
+ struct tomoyo_profile *p;
+ if (!tomoyo_policy_loaded)
+ return false;
+ p = tomoyo_profile(profile);
+ if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG])
+ return false;
+ mode = p->config[index];
+ if (mode == TOMOYO_CONFIG_USE_DEFAULT)
+ mode = p->config[category];
+ if (mode == TOMOYO_CONFIG_USE_DEFAULT)
+ mode = p->default_config;
+ if (is_granted)
+ return mode & TOMOYO_CONFIG_WANT_GRANT_LOG;
+ return mode & TOMOYO_CONFIG_WANT_REJECT_LOG;
+}
+
+/**
+ * tomoyo_write_log2 - Write an audit log.
+ *
+ * @r: Pointer to "struct tomoyo_request_info".
+ * @len: Buffer size needed for @fmt and @args.
+ * @fmt: The printf()'s format string.
+ * @args: va_list structure for @fmt.
+ *
+ * Returns nothing.
+ */
+void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt,
+ va_list args)
+{
+ char *buf;
+ struct tomoyo_log *entry;
+ bool quota_exceeded = false;
+ if (!tomoyo_get_audit(r->profile, r->type, r->granted))
+ goto out;
+ buf = tomoyo_init_log(r, len, fmt, args);
+ if (!buf)
+ goto out;
+ entry = kzalloc(sizeof(*entry), GFP_NOFS);
+ if (!entry) {
+ kfree(buf);
+ goto out;
+ }
+ entry->log = buf;
+ len = tomoyo_round2(strlen(buf) + 1);
+ /*
+ * The entry->size is used for memory quota checks.
+ * Don't go beyond strlen(entry->log).
+ */
+ entry->size = len + tomoyo_round2(sizeof(*entry));
+ spin_lock(&tomoyo_log_lock);
+ if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] &&
+ tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >=
+ tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) {
+ quota_exceeded = true;
+ } else {
+ tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size;
+ list_add_tail(&entry->list, &tomoyo_log);
+ tomoyo_log_count++;
+ }
+ spin_unlock(&tomoyo_log_lock);
+ if (quota_exceeded) {
+ kfree(buf);
+ kfree(entry);
+ goto out;
+ }
+ wake_up(&tomoyo_log_wait);
+out:
+ return;
+}
+
+/**
+ * tomoyo_write_log - Write an audit log.
+ *
+ * @r: Pointer to "struct tomoyo_request_info".
+ * @fmt: The printf()'s format string, followed by parameters.
+ *
+ * Returns nothing.
+ */
+void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...)
+{
+ va_list args;
+ int len;
+ va_start(args, fmt);
+ len = vsnprintf((char *) &len, 1, fmt, args) + 1;
+ va_end(args);
+ va_start(args, fmt);
+ tomoyo_write_log2(r, len, fmt, args);
+ va_end(args);
+}
+
+/**
+ * tomoyo_read_log - Read an audit log.
+ *
+ * @head: Pointer to "struct tomoyo_io_buffer".
+ *
+ * Returns nothing.
+ */
+void tomoyo_read_log(struct tomoyo_io_buffer *head)
+{
+ struct tomoyo_log *ptr = NULL;
+ if (head->r.w_pos)
+ return;
+ kfree(head->read_buf);
+ head->read_buf = NULL;
+ spin_lock(&tomoyo_log_lock);
+ if (!list_empty(&tomoyo_log)) {
+ ptr = list_entry(tomoyo_log.next, typeof(*ptr), list);
+ list_del(&ptr->list);
+ tomoyo_log_count--;
+ tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size;
+ }
+ spin_unlock(&tomoyo_log_lock);
+ if (ptr) {
+ head->read_buf = ptr->log;
+ head->r.w[head->r.w_pos++] = head->read_buf;
+ kfree(ptr);
+ }
+}
+
+/**
+ * tomoyo_poll_log - Wait for an audit log.
+ *
+ * @file: Pointer to "struct file".
+ * @wait: Pointer to "poll_table".
+ *
+ * Returns POLLIN | POLLRDNORM when ready to read an audit log.
+ */
+int tomoyo_poll_log(struct file *file, poll_table *wait)
+{
+ if (tomoyo_log_count)
+ return POLLIN | POLLRDNORM;
+ poll_wait(file, &tomoyo_log_wait, wait);
+ if (tomoyo_log_count)
+ return POLLIN | POLLRDNORM;
+ return 0;
+}