Add Linux audit support.

plugins/sudoers/linux_audit.c

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2010 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <config.h>
+
+#include <sys/types.h>
+#include <stdio.h>
+#ifdef STDC_HEADERS
+# include <stdlib.h>
+# include <stddef.h>
+#else
+# ifdef HAVE_STDLIB_H
+#  include <stdlib.h>
+# endif
+#endif /* STDC_HEADERS */
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <libaudit.h>
+
+#include <compat.h>
+#include <error.h>
+#include <alloc.h>
+#include <missing.h>
+#include <linux_audit.h>
+
+/*
+ * Open audit connection if possible.
+ * Returns audit fd on success and -1 on failure.
+ */
+static int
+linux_audit_open(void)
+{
+    static int au_fd = -1;
+
+    if (au_fd != -1)
+	return au_fd;
+    au_fd = audit_open();
+    if (au_fd == -1) {
+	/* Kernel may not have audit support. */
+	if (errno != EINVAL && errno != EPROTONOSUPPORT && errno != EAFNOSUPPORT)
+	    error(1, "unable to open audit system");
+    } else {
+	(void)fcntl(au_fd, F_SETFD, FD_CLOEXEC);
+    }
+    return au_fd;
+}
+
+int
+linux_audit_command(char *argv[], int result)
+{
+    int au_fd, rc;
+    char *command, *cp, **av;
+    size_t size, n;
+
+    if ((au_fd = linux_audit_open()) == -1)
+	return -1;
+
+    /* Convert argv to a flat string. */
+    for (size = 0, av = argv; *av != NULL; av++)
+	size += strlen(*av) + 1;
+    command = cp = emalloc(size);
+    for (av = argv; *av != NULL; av++) {
+	n = strlcpy(cp, *av, size - (cp - command));
+	if (n >= size - (cp - command))
+	    errorx(1, "internal error, linux_audit_command() overflow");
+	cp += n;
+	*cp++ = ' ';
+    }
+    *--cp = '\0';
+
+    /* Log command, ignoring EPERM on error. */
+    rc = audit_log_user_command(au_fd, AUDIT_USER_CMD, command, NULL, result);
+    if (rc <= 0)
+	warning("unable to send audit message");
+
+    efree(command);
+
+    return rc;
+}