First, the setting of SCTP_EVENTS socket option in sctp_server.c is
completely wrong -- it assumes little-endian byte order and uses a plain
int instead of the dedicated sctp_event_subscribe struct.
Second, the usage in sctp_peeloff_server.c is correct, but it may lead
to errors when the SCTP header definitions are newer than what the
kernel supports. In such case the size of struct sctp_event_subscribe
may be higher than the kernel's version and the setsockopt(2) may fail
with -EINVAL due to the 'optlen > sizeof(struct sctp_event_subscribe)'
check in net/sctp/socket.c:sctp_setsockopt_events().
To fix this, introduce a common function that does what the
sctp_peeloff_server's set_subscr_events() did, but also truncates the
optlen to only those fields that we use.
Fixes: c38b57ffdac4 ("selinux-testsuite: Add SCTP test support")
Signed-off-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
---
tests/sctp/sctp_common.c | 20 ++++++++++++++++++++
tests/sctp/sctp_common.h | 1 +
tests/sctp/sctp_peeloff_server.c | 28 ++++++++--------------------
tests/sctp/sctp_server.c | 2 +-
4 files changed, 30 insertions(+), 21 deletions(-)
diff --git a/tests/sctp/sctp_common.c b/tests/sctp/sctp_common.c
index 100ab22..089af2a 100644
--- a/tests/sctp/sctp_common.c
+++ b/tests/sctp/sctp_common.c
@@ -1,5 +1,8 @@
#include "sctp_common.h"
+#define member_size(type, member) sizeof(((type *)0)->member)
+#define sizeof_up_to(type, member) (offsetof(type, member) + member_size(type, member))
+
void print_context(int fd, char *text)
{
char *context;
@@ -99,3 +102,20 @@ void print_ip_option(int fd, bool ipv4, char *text)
printf("%s No IP Options set\n", text);
}
}
+
+int set_subscr_events(int fd, int data_io, int association)
+{
+ struct sctp_event_subscribe subscr_events;
+
+ memset(&subscr_events, 0, sizeof(subscr_events));
+ subscr_events.sctp_data_io_event = data_io;
+ subscr_events.sctp_association_event = association;
+
+ /*
+ * Truncate optlen to just the fields we touch to avoid errors when
+ * the uapi headers are newer than the running kernel.
+ */
+ return setsockopt(fd, IPPROTO_SCTP, SCTP_EVENTS, &subscr_events,
+ sizeof_up_to(struct sctp_event_subscribe,
+ sctp_association_event));
+}
diff --git a/tests/sctp/sctp_common.h b/tests/sctp/sctp_common.h
index d5c1397..351ee37 100644
--- a/tests/sctp/sctp_common.h
+++ b/tests/sctp/sctp_common.h
@@ -25,3 +25,4 @@ void print_context(int fd, char *text);
void print_addr_info(struct sockaddr *sin, char *text);
char *get_ip_option(int fd, bool ipv4, socklen_t *opt_len);
void print_ip_option(int fd, bool ipv4, char *text);
+int set_subscr_events(int fd, int data_io, int association);
diff --git a/tests/sctp/sctp_peeloff_server.c b/tests/sctp/sctp_peeloff_server.c
index 4a5110a..093c6c0 100644
--- a/tests/sctp/sctp_peeloff_server.c
+++ b/tests/sctp/sctp_peeloff_server.c
@@ -16,24 +16,6 @@ static void usage(char *progname)
exit(1);
}
-static void set_subscr_events(int fd, int value)
-{
- int result;
- struct sctp_event_subscribe subscr_events;
-
- memset(&subscr_events, 0, sizeof(subscr_events));
- subscr_events.sctp_association_event = value;
- /* subscr_events.sctp_data_io_event = value; */
-
- result = setsockopt(fd, IPPROTO_SCTP, SCTP_EVENTS,
- &subscr_events, sizeof(subscr_events));
- if (result < 0) {
- perror("Server setsockopt: SCTP_EVENTS");
- close(fd);
- exit(1);
- }
-}
-
static sctp_assoc_t handle_event(void *buf)
{
union sctp_notification *snp = buf;
@@ -166,7 +148,13 @@ int main(int argc, char **argv)
}
do {
- set_subscr_events(sock, 1); /* Get assoc_id for sctp_peeloff() */
+ /* Get assoc_id for sctp_peeloff() */
+ result = set_subscr_events(sock, 0, 1);
+ if (result < 0) {
+ perror("Server setsockopt: SCTP_EVENTS");
+ close(sock);
+ exit(1);
+ }
sinlen = sizeof(sin);
flags = 0;
@@ -192,7 +180,7 @@ int main(int argc, char **argv)
exit(1);
}
/* No more notifications */
- set_subscr_events(sock, 0);
+ set_subscr_events(sock, 0, 0);
peeloff_sk = sctp_peeloff(sock, assoc_id);
if (peeloff_sk < 0) {
diff --git a/tests/sctp/sctp_server.c b/tests/sctp/sctp_server.c
index 4659ed1..7f2cd20 100644
--- a/tests/sctp/sctp_server.c
+++ b/tests/sctp/sctp_server.c
@@ -134,7 +134,7 @@ int main(int argc, char **argv)
}
/* Enables sctp_data_io_events for sctp_recvmsg(3) for assoc_id. */
- result = setsockopt(sock, SOL_SCTP, SCTP_EVENTS, &on, sizeof(on));
+ result = set_subscr_events(sock, on, 0);
if (result < 0) {
perror("Server setsockopt: SCTP_EVENTS");
close(sock);
--
2.24.1
