/*
* This function will return 0 if auditing is NOT enabled and
* 1 if enabled, and -1 on error.
*/
int audit_is_enabled(int fd)
{
int rc;
if (fd < 0)
return 0;
if ((rc = audit_request_status(fd)) > 0) {
struct audit_reply rep;
int i;
int timeout = 40; /* tenths of seconds */
struct pollfd pfd[1];
pfd[0].fd = fd;
pfd[0].events = POLLIN;
for (i = 0; i < timeout; i++) {
do {
rc = poll(pfd, 1, 100);
} while (rc < 0 && errno == EINTR);
rc = audit_get_reply(fd, &rep, GET_REPLY_NONBLOCKING,0);
if (rc > 0) {
/* If we get done or error, break out */
if (rep.type == NLMSG_DONE ||
rep.type == NLMSG_ERROR)
break;
/* If its not status, keep looping */
if (rep.type != AUDIT_GET)
continue;
/* Found it... */
return rep.status->enabled;
}
}
}
if (rc == -ECONNREFUSED) {
/* This is here to let people that build their own kernel
and disable the audit system get in. ECONNREFUSED is
issued by the kernel when there is "no on listening". */
return 0;
} else if (rc == -EPERM && getuid() != 0) {
/* If we get this, then the kernel supports auditing
* but we don't have enough privilege to write to the
* socket. Therefore, we have already been authenticated
* and we are a common user. Just act as though auditing
* is not enabled. Any other error we take seriously.
* This is here basically to satisfy Xscreensaver. */
return 0;
}
return -1;
}
/*
* returns: -3 deprecated, -2 success - no reply, -1 error - noreply,
* 0 success - reply, > 0 success - rule
*/
static int setopt(int count, int lineno, char *vars[])
{
int c;
int retval = 0, rc;
optind = 0;
opterr = 0;
key[0] = 0;
keylen = AUDIT_MAX_KEY_LEN;
while ((retval >= 0) && (c = getopt(count, vars,
"hicslDvtC:e:f:r:b:a:A:d:S:F:m:R:w:W:k:p:q:")) != EOF) {
int flags = AUDIT_FILTER_UNSET;
rc = 10; // Init to something impossible to see if unused.
switch (c) {
case 'h':
usage();
retval = -1;
break;
case 'i':
ignore = 1;
retval = -2;
break;
case 'c':
ignore = 1;
continue_error = 1;
retval = -2;
break;
case 's':
retval = audit_request_status(fd);
if (retval <= 0)
retval = -1;
else
retval = 0; /* success - just get the reply */
break;
case 'e':
if (optarg && ((strcmp(optarg, "0") == 0) ||
(strcmp(optarg, "1") == 0) ||
(strcmp(optarg, "2") == 0))) {
if (audit_set_enabled(fd, strtoul(optarg,NULL,0)) > 0)
audit_request_status(fd);
else
retval = -1;
} else {
fprintf(stderr, "Enable must be 0, 1, or 2 was %s\n",
optarg);
retval = -1;
}
break;
case 'f':
if (optarg && ((strcmp(optarg, "0") == 0) ||
(strcmp(optarg, "1") == 0) ||
(strcmp(optarg, "2") == 0))) {
if (audit_set_failure(fd, strtoul(optarg,NULL,0)) > 0)
audit_request_status(fd);
else
return -1;
} else {
fprintf(stderr, "Failure must be 0, 1, or 2 was %s\n",
optarg);
retval = -1;
}
break;
case 'r':
if (optarg && isdigit(optarg[0])) {
uint32_t rate;
errno = 0;
rate = strtoul(optarg,NULL,0);
if (errno) {
fprintf(stderr, "Error converting rate\n");
return -1;
}
if (audit_set_rate_limit(fd, rate) > 0)
audit_request_status(fd);
else
return -1;
} else {
fprintf(stderr, "Rate must be a numeric value was %s\n",
optarg);
retval = -1;
}
break;
case 'b':
if (optarg && isdigit(optarg[0])) {
uint32_t limit;
errno = 0;
limit = strtoul(optarg,NULL,0);
if (errno) {
fprintf(stderr, "Error converting backlog\n");
return -1;
}
if (audit_set_backlog_limit(fd, limit) > 0)
audit_request_status(fd);
else
return -1;
} else {
fprintf(stderr,
"Backlog must be a numeric value was %s\n",
optarg);
retval = -1;
}
break;
case 'l':
if (count > 4 || count == 3) {
fprintf(stderr,
"Wrong number of options for list request\n");
retval = -1;
break;
}
if (count == 4) {
if (strcmp(vars[optind], "-k") == 0) {
strncat(key, vars[3], keylen);
count -= 2;
} else {
fprintf(stderr,
"Only the -k option is allowed\n");
retval = -1;
break;
}
}
if (audit_request_rule_list(fd))
retval = -2;
else
retval = -1;
break;
case 'a':
if (strstr(optarg, "task") && _audit_syscalladded) {
fprintf(stderr,
"Syscall auditing requested for task list\n");
retval = -1;
} else {
rc = audit_rule_setup(optarg, &add, &action, lineno);
if (rc == 3) {
fprintf(stderr,
"Multiple rule insert/delete operations are not allowed\n");
retval = -1;
} else if (rc == 2) {
fprintf(stderr,
"Append rule - bad keyword %s\n",
optarg);
retval = -1;
} else if (rc == 1) {
fprintf(stderr,
"Append rule - possible is deprecated\n");
return -3; /* deprecated - eat it */
} else
retval = 1; /* success - please send */
}
break;
case 'A':
if (strstr(optarg, "task") && _audit_syscalladded) {
fprintf(stderr,
"Error: syscall auditing requested for task list\n");
retval = -1;
} else {
rc = audit_rule_setup(optarg, &add, &action, lineno);
if (rc == 3) {
fprintf(stderr,
"Multiple rule insert/delete operations are not allowed\n");
retval = -1;
} else if (rc == 2) {
fprintf(stderr,
"Add rule - bad keyword %s\n", optarg);
retval = -1;
} else if (rc == 1) {
fprintf(stderr,
"Append rule - possible is deprecated\n");
return -3; /* deprecated - eat it */
} else {
add |= AUDIT_FILTER_PREPEND;
retval = 1; /* success - please send */
}
}
break;
case 'd':
rc = audit_rule_setup(optarg, &del, &action, lineno);
if (rc == 3) {
fprintf(stderr,
"Multiple rule insert/delete operations are not allowed\n");
retval = -1;
} else if (rc == 2) {
fprintf(stderr, "Delete rule - bad keyword %s\n",
optarg);
retval = -1;
} else if (rc == 1) {
fprintf(stderr,
"Delete rule - possible is deprecated\n");
return -3; /* deprecated - eat it */
} else
retval = 1; /* success - please send */
break;
case 'S': {
int unknown_arch = !_audit_elf;
/* Do some checking to make sure that we are not adding a
* syscall rule to a list that does not make sense. */
if (((add & (AUDIT_FILTER_MASK|AUDIT_FILTER_UNSET)) ==
AUDIT_FILTER_TASK || (del &
(AUDIT_FILTER_MASK|AUDIT_FILTER_UNSET)) ==
AUDIT_FILTER_TASK)) {
fprintf(stderr,
"Error: syscall auditing being added to task list\n");
return -1;
} else if (((add & (AUDIT_FILTER_MASK|AUDIT_FILTER_UNSET)) ==
AUDIT_FILTER_USER || (del &
(AUDIT_FILTER_MASK|AUDIT_FILTER_UNSET)) ==
AUDIT_FILTER_USER)) {
fprintf(stderr,
"Error: syscall auditing being added to user list\n");
return -1;
} else if (exclude) {
fprintf(stderr,
"Error: syscall auditing cannot be put on exclude list\n");
return -1;
} else {
if (unknown_arch) {
int machine;
unsigned int elf;
machine = audit_detect_machine();
if (machine < 0) {
fprintf(stderr,
"Error detecting machine type\n");
return -1;
}
elf = audit_machine_to_elf(machine);
if (elf == 0) {
fprintf(stderr,
"Error looking up elf type\n");
return -1;
}
_audit_elf = elf;
}
}
rc = audit_rule_syscallbyname_data(rule_new, optarg);
switch (rc)
{
case 0:
_audit_syscalladded = 1;
if (unknown_arch && add != AUDIT_FILTER_UNSET)
check_rule_mismatch(lineno, optarg);
break;
case -1:
fprintf(stderr, "Syscall name unknown: %s\n",
optarg);
retval = -1;
break;
case -2:
fprintf(stderr, "Elf type unknown: 0x%x\n",
_audit_elf);
retval = -1;
break;
}}
break;
case 'F':
if (add != AUDIT_FILTER_UNSET)
flags = add & AUDIT_FILTER_MASK;
else if (del != AUDIT_FILTER_UNSET)
flags = del & AUDIT_FILTER_MASK;
// if the field is arch & there is a -t option...we
// can allow it
else if ((optind >= count) || (strstr(optarg, "arch=") == NULL)
|| (strcmp(vars[optind], "-t") != 0)) {
fprintf(stderr, "List must be given before field\n");
retval = -1;
break;
}
rc = audit_rule_fieldpair_data(&rule_new,optarg,flags);
if (rc != 0) {
audit_number_to_errmsg(rc, optarg);
retval = -1;
} else {
if (rule_new->fields[rule_new->field_count-1] ==
AUDIT_PERM)
_audit_permadded = 1;
}
break;
case 'C':
if (add != AUDIT_FILTER_UNSET)
flags = add & AUDIT_FILTER_MASK;
else if (del != AUDIT_FILTER_UNSET)
flags = del & AUDIT_FILTER_MASK;
rc = audit_rule_interfield_comp_data(&rule_new, optarg, flags);
if (rc != 0) {
audit_number_to_errmsg(rc, optarg);
retval = -1;
} else {
if (rule_new->fields[rule_new->field_count - 1] ==
AUDIT_PERM)
_audit_permadded = 1;
}
break;
case 'm':
if (count > 3) {
fprintf(stderr,
"The -m option must be only the only option and takes 1 parameter\n");
retval = -1;
} else if (audit_log_user_message( fd, AUDIT_USER,
optarg, NULL, NULL, NULL, 1) <= 0)
retval = -1;
else
return -2; // success - no reply for this
break;
case 'R':
fprintf(stderr, "Error - nested rule files not supported\n");
retval = -1;
break;
case 'D':
if (count > 4 || count == 3) {
fprintf(stderr,
"Wrong number of options for Delete all request\n");
retval = -1;
break;
}
if (count == 4) {
if (strcmp(vars[optind], "-k") == 0) {
strncat(key, vars[3], keylen);
count -= 2;
} else {
fprintf(stderr,
"Only the -k option is allowed\n");
retval = -1;
break;
}
}
retval = delete_all_rules(fd);
if (retval == 0) {
(void)audit_request_rule_list(fd);
key[0] = 0;
retval = -2;
}
break;
case 'w':
if (add != AUDIT_FILTER_UNSET ||
del != AUDIT_FILTER_UNSET) {
fprintf(stderr,
"watch option can't be given with a syscall\n");
retval = -1;
} else if (optarg) {
add = AUDIT_FILTER_EXIT;
action = AUDIT_ALWAYS;
_audit_syscalladded = 1;
retval = audit_setup_watch_name(&rule_new, optarg);
} else {
fprintf(stderr, "watch option needs a path\n");
retval = -1;
}
break;
case 'W':
if (optarg) {
del = AUDIT_FILTER_EXIT;
action = AUDIT_ALWAYS;
_audit_syscalladded = 1;
retval = audit_setup_watch_name(&rule_new, optarg);
} else {
fprintf(stderr, "watch option needs a path\n");
retval = -1;
}
break;
case 'k':
if (!(_audit_syscalladded || _audit_permadded ) ||
(add==AUDIT_FILTER_UNSET &&
del==AUDIT_FILTER_UNSET)) {
fprintf(stderr,
"key option needs a watch or syscall given prior to it\n");
retval = -1;
} else if (!optarg) {
fprintf(stderr, "key option needs a value\n");
retval = -1;
} else if ((strlen(optarg)+strlen(key)+(!!key[0])) >
AUDIT_MAX_KEY_LEN) {
fprintf(stderr, "key option exceeds size limit\n");
retval = -1;
} else {
if (strncmp(optarg, "ids-", 4) == 0) {
if (check_ids_key(optarg)) {
retval = -1;
break;
}
}
if (strchr(optarg, AUDIT_KEY_SEPARATOR))
fprintf(stderr,
"key %s has illegal character\n", optarg);
if (key[0]) { // Add the separator if we need to
strcat(key, key_sep);
keylen--;
}
strncat(key, optarg, keylen);
keylen = AUDIT_MAX_KEY_LEN - strlen(key);
}
break;
case 'p':
if (!add && !del) {
fprintf(stderr,
"permission option needs a watch given prior to it\n");
retval = -1;
} else if (!optarg) {
fprintf(stderr, "permission option needs a filter\n");
retval = -1;
} else
retval = audit_setup_perms(rule_new, optarg);
break;
case 'q':
if (_audit_syscalladded) {
fprintf(stderr,
"Syscall auditing requested for make equivalent\n");
retval = -1;
} else {
char *mp, *sub;
retval = equiv_parse(optarg, &mp, &sub);
if (retval < 0) {
fprintf(stderr,
"Error parsing equivalent parts\n");
retval = -1;
} else {
retval = audit_make_equivalent(fd, mp, sub);
if (retval <= 0) {
retval = -1;
} else
return -2; // success - no reply needed
}
}
break;
case 't':
retval = audit_trim_subtrees(fd);
if (retval <= 0)
retval = -1;
else
return -2; // success - no reply for this
break;
case 'v':
printf("auditctl version %s\n", VERSION);
retval = -2;
break;
default:
usage();
retval = -1;
break;
}
}
/* catch extra args or errors where the user types "- s" */
if (optind == 1)
retval = -1;
else if ((optind < count) && (retval != -1)) {
fprintf(stderr, "parameter passed without an option given\n");
retval = -1;
}
/* See if we were adding a key */
if (key[0] && list_requested == 0) {
int flags = 0;
char *cmd=NULL;
/* Get the flag */
if (add != AUDIT_FILTER_UNSET)
flags = add & AUDIT_FILTER_MASK;
else if (del != AUDIT_FILTER_UNSET)
flags = del & AUDIT_FILTER_MASK;
/* Build the command */
asprintf(&cmd, "key=%s", key);
if (cmd) {
/* Add this to the rule */
int ret = audit_rule_fieldpair_data(&rule_new, cmd, flags);
if (ret < 0)
retval = -1;
free(cmd);
} else {
fprintf(stderr, "Out of memory adding key\n");
retval = -1;
}
}
if (retval == -1 && errno == ECONNREFUSED)
fprintf(stderr, "The audit system is disabled\n");
return retval;
}
Status AuditEventPublisher::run() {
if (!FLAGS_disable_audit && (count_ == 0 || count_++ % 10 == 0)) {
// Request an update to the audit status.
// This will also fill in the status on first run.
audit_request_status(handle_);
}
// Reset the reply data.
int result = 0;
bool handle_reply = false;
while (true) {
handle_reply = false;
// Request a reply in a non-blocking mode.
// This allows the publisher's run loop to periodically request an audit
// status update. These updates can check for other processes attempting to
// gain control over the audit sink.
// This non-blocking also allows faster receipt of multi-message events.
result = audit_get_reply(handle_, &reply_, GET_REPLY_NONBLOCKING, 0);
if (result > 0) {
switch (reply_.type) {
case NLMSG_NOOP:
case NLMSG_DONE:
case NLMSG_ERROR:
// Not handled, request another reply.
break;
case AUDIT_LIST_RULES:
// Build rules cache.
handleListRules();
break;
case AUDIT_GET:
// Make a copy of the status reply and store as the most-recent.
if (reply_.status != nullptr) {
memcpy(&status_, reply_.status, sizeof(struct audit_status));
}
break;
case (AUDIT_GET + 1)...(AUDIT_LIST_RULES - 1):
case (AUDIT_LIST_RULES + 1)... AUDIT_LAST_USER_MSG:
// Not interested in handling meta-commands and actions.
break;
case AUDIT_DAEMON_START... AUDIT_DAEMON_CONFIG: // 1200 - 1203
case AUDIT_CONFIG_CHANGE:
handleAuditConfigChange(reply_);
break;
case AUDIT_SYSCALL: // 1300
// A monitored syscall was issued, most likely part of a multi-record.
handle_reply = true;
break;
case AUDIT_CWD: // 1307
case AUDIT_PATH: // 1302
case AUDIT_EXECVE: // // 1309 (execve arguments).
handle_reply = true;
case AUDIT_EOE: // 1320 (multi-record event).
break;
default:
// All other cases, pass to reply.
handle_reply = true;
}
} else {
// Fall through to the run loop cool down.
break;
}
// Replies are 'handled' as potential events for several audit types.
if (handle_reply) {
auto ec = createEventContext();
// Build the event context from the reply type and parse the message.
if (handleAuditReply(reply_, ec)) {
fire(ec);
}
}
}
