[PATCH 2/2] lost_reset: return value rather than sequence number when zero
The kernel always returns negative values on error, so zero and anything
positive is valid success. Lost_reset returned a positive value at the
time of reset, including zero that got interpreted as success and
replaced with the packet sequence number "2".
Rename audit_send() to __audit_send() and pass the sequence number back
via a parameter rather than return value.
Have a new stub audit_send() call __audit_send() and mimic the previous
behaviour of audit_send().
There are legacy functions that actually use a sequence number:
audit_request_rules_list_data()
delete_all_rules()
audit_request_signal_info()
src/auditd.c:get_reply()
A number of others don't appear to need it, but expose it in libaudit:
audit_send_user_message()
audit_log_user_comm_message()
audit_log_acct_message()
audit_log_user_avc_message()
audit_log_semanage_message()
audit_log_user_command()
audit_request_status()
audit_set_enabled()
audit_set_failure()
audit_set_rate_limit()
audit_set_backlog_limit()
audit_set_backlog_wait_time()
audit_add_rule_data()
audit_delete_rule_data()
Passes all audit-testsuite tests.
See: https://github.com/linux-audit/audit-userspace/issues/31
Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com>
---
lib/libaudit.c | 3 ++-
lib/netlink.c | 28 ++++++++++++++++++++--------
lib/private.h | 1 +
3 files changed, 23 insertions(+), 9 deletions(-)
diff --git a/lib/libaudit.c b/lib/libaudit.c
index a9ba575..aa8258c 100644
--- a/lib/libaudit.c
+++ b/lib/libaudit.c
@@ -519,6 +519,7 @@ int audit_set_backlog_wait_time(int fd, uint32_t bwt)
int audit_reset_lost(int fd)
{
int rc;
+ int seq;
struct audit_status s;
if ((audit_get_features() & AUDIT_FEATURE_BITMAP_LOST_RESET) == 0)
@@ -527,7 +528,7 @@ int audit_reset_lost(int fd)
memset(&s, 0, sizeof(s));
s.mask = AUDIT_STATUS_LOST;
s.lost = 0;
- rc = audit_send(fd, AUDIT_SET, &s, sizeof(s));
+ rc = __audit_send(fd, AUDIT_SET, &s, sizeof(s), &seq);
if (rc < 0)
audit_msg(audit_priority(errno),
"Error sending lost reset request (%s)",
diff --git a/lib/netlink.c b/lib/netlink.c
index 6e23883..5b2028f 100644
--- a/lib/netlink.c
+++ b/lib/netlink.c
@@ -203,7 +203,7 @@ static int adjust_reply(struct audit_reply *rep, int len)
* error: -errno
* short: 0
*/
-int audit_send(int fd, int type, const void *data, unsigned int size)
+int __audit_send(int fd, int type, const void *data, unsigned int size, int *seq)
{
static int sequence = 0;
struct audit_message req;
@@ -224,6 +224,7 @@ int audit_send(int fd, int type, const void *data, unsigned int size)
if (++sequence < 0)
sequence = 1;
+ *seq = sequence;
memset(&req, 0, sizeof(req));
req.nlh.nlmsg_len = NLMSG_SPACE(size);
@@ -241,18 +242,29 @@ int audit_send(int fd, int type, const void *data, unsigned int
size)
retval = sendto(fd, &req, req.nlh.nlmsg_len, 0,
(struct sockaddr*)&addr, sizeof(addr));
} while (retval < 0 && errno == EINTR);
- if (retval == (int)req.nlh.nlmsg_len) {
- if ((retval = check_ack(fd)) == 0)
- return sequence;
- else
- return retval;
- }
- if (retval < 0)
+ if (retval == (int)req.nlh.nlmsg_len)
+ return check_ack(fd);
+ if (retval < 0) {
return -errno;
+ } else if (retval > 0) {
+ errno = EINVAL;
+ return -errno;
+ }
return 0;
}
+int audit_send(int fd, int type, const void *data, unsigned int size)
+{
+ int rc;
+ int seq;
+
+ rc = __audit_send(fd, type, data, size, &seq);
+ if (rc == 0)
+ rc = seq;
+ return rc;
+}
+
/*
* This function will take a peek into the next packet and see if there's
* an error. If so, the error is returned and its non-zero. Otherwise a
diff --git a/lib/private.h b/lib/private.h
index dbe0f74..560740f 100644
--- a/lib/private.h
+++ b/lib/private.h
@@ -121,6 +121,7 @@ void audit_msg(int priority, const char *fmt, ...)
#endif
extern int audit_send(int fd, int type, const void *data, unsigned int size);
+extern int __audit_send(int fd, int type, const void *data, unsigned int size, int
*seq);
AUDIT_HIDDEN_START
--
1.8.3.1