Minimize the risk that psock_fanout leaves loopback device in a different
state than the start state.

Restore loopback up/down state when test reaches end of main.
For abort on errors, globally replace all 'exit' with 'cleanup_and_exit'
that restores loopback up/down state.

Signed-off-by: Gur Stavi <gur.stavi@huawei.com>
---
 tools/testing/selftests/net/psock_fanout.c | 73 +++++++++++-----------
 1 file changed, 37 insertions(+), 36 deletions(-)

diff --git a/tools/testing/selftests/net/psock_fanout.c b/tools/testing/selftests/net/psock_fanout.c
index a8b22494a635..64edcd661d43 100644
--- a/tools/testing/selftests/net/psock_fanout.c
+++ b/tools/testing/selftests/net/psock_fanout.c
@@ -108,7 +108,7 @@ static int sock_fanout_open(uint16_t typeflags, uint16_t group_id)
 	fd = socket(PF_PACKET, SOCK_RAW, 0);
 	if (fd < 0) {
 		perror("socket packet");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	pair_udp_setfilter(fd);
@@ -118,11 +118,11 @@ static int sock_fanout_open(uint16_t typeflags, uint16_t group_id)
 	addr.sll_ifindex = if_nametoindex("lo");
 	if (addr.sll_ifindex == 0) {
 		perror("if_nametoindex");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 	if (bind(fd, (void *) &addr, sizeof(addr))) {
 		perror("bind packet");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	if (cfg_max_num_members) {
@@ -139,7 +139,7 @@ static int sock_fanout_open(uint16_t typeflags, uint16_t group_id)
 	if (err) {
 		if (close(fd)) {
 			perror("close packet");
-			exit(1);
+			cleanup_and_exit(1);
 		}
 		return -1;
 	}
@@ -161,7 +161,7 @@ static void sock_fanout_set_cbpf(int fd)
 	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &bpf_prog,
 		       sizeof(bpf_prog))) {
 		perror("fanout data cbpf");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 }
 
@@ -173,7 +173,7 @@ static void sock_fanout_getopts(int fd, uint16_t *typeflags, uint16_t *group_id)
 	if (getsockopt(fd, SOL_PACKET, PACKET_FANOUT,
 		       &sockopt, &sockopt_len)) {
 		perror("failed to getsockopt");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 	*typeflags = sockopt >> 16;
 	*group_id = sockopt & 0xfffff;
@@ -211,17 +211,17 @@ static void sock_fanout_set_ebpf(int fd)
 	if (pfd < 0) {
 		perror("bpf");
 		fprintf(stderr, "bpf verifier:\n%s\n", log_buf);
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &pfd, sizeof(pfd))) {
 		perror("fanout data ebpf");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	if (close(pfd)) {
 		perror("close ebpf");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 }
 
@@ -239,19 +239,19 @@ static char *sock_fanout_open_ring(int fd)
 	if (setsockopt(fd, SOL_PACKET, PACKET_VERSION, (void *) &val,
 		       sizeof(val))) {
 		perror("packetsock ring setsockopt version");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 	if (setsockopt(fd, SOL_PACKET, PACKET_RX_RING, (void *) &req,
 		       sizeof(req))) {
 		perror("packetsock ring setsockopt");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	ring = mmap(0, req.tp_block_size * req.tp_block_nr,
 		    PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
 	if (ring == MAP_FAILED) {
 		perror("packetsock ring mmap");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	return ring;
@@ -297,7 +297,7 @@ static void test_control_single(void)
 	if (sock_fanout_open(PACKET_FANOUT_ROLLOVER |
 			       PACKET_FANOUT_FLAG_ROLLOVER, 0) != -1) {
 		fprintf(stderr, "ERROR: opened socket with dual rollover\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 }
 
@@ -311,30 +311,30 @@ static void test_control_group(void)
 	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
 	if (fds[0] == -1) {
 		fprintf(stderr, "ERROR: failed to open HASH socket\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 	if (sock_fanout_open(PACKET_FANOUT_HASH |
 			       PACKET_FANOUT_FLAG_DEFRAG, 0) != -1) {
 		fprintf(stderr, "ERROR: joined group with wrong flag defrag\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 	if (sock_fanout_open(PACKET_FANOUT_HASH |
 			       PACKET_FANOUT_FLAG_ROLLOVER, 0) != -1) {
 		fprintf(stderr, "ERROR: joined group with wrong flag ro\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 	if (sock_fanout_open(PACKET_FANOUT_CPU, 0) != -1) {
 		fprintf(stderr, "ERROR: joined group with wrong mode\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
 	if (fds[1] == -1) {
 		fprintf(stderr, "ERROR: failed to join group\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 	if (close(fds[1]) || close(fds[0])) {
 		fprintf(stderr, "ERROR: closing sockets\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 }
 
@@ -349,21 +349,21 @@ static void test_control_group_max_num_members(void)
 	cfg_max_num_members = (1 << 16) + 1;
 	if (sock_fanout_open(PACKET_FANOUT_HASH, 0) != -1) {
 		fprintf(stderr, "ERROR: max_num_members > PACKET_FANOUT_MAX\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	cfg_max_num_members = 256;
 	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
 	if (fds[0] == -1) {
 		fprintf(stderr, "ERROR: failed open\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	/* expected failure on joining group with different max_num_members */
 	cfg_max_num_members = 257;
 	if (sock_fanout_open(PACKET_FANOUT_HASH, 0) != -1) {
 		fprintf(stderr, "ERROR: set different max_num_members\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	/* success on joining group with same max_num_members */
@@ -371,7 +371,7 @@ static void test_control_group_max_num_members(void)
 	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
 	if (fds[1] == -1) {
 		fprintf(stderr, "ERROR: failed to join group\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	/* success on joining group with max_num_members unspecified */
@@ -379,12 +379,12 @@ static void test_control_group_max_num_members(void)
 	fds[2] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
 	if (fds[2] == -1) {
 		fprintf(stderr, "ERROR: failed to join group\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	if (close(fds[2]) || close(fds[1]) || close(fds[0])) {
 		fprintf(stderr, "ERROR: closing sockets\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 }
 
@@ -400,25 +400,25 @@ static void test_unique_fanout_group_ids(void)
 				  PACKET_FANOUT_FLAG_UNIQUEID, 0);
 	if (fds[0] == -1) {
 		fprintf(stderr, "ERROR: failed to create a unique id group.\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	sock_fanout_getopts(fds[0], &typeflags, &first_group_id);
 	if (typeflags != PACKET_FANOUT_HASH) {
 		fprintf(stderr, "ERROR: unexpected typeflags %x\n", typeflags);
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	if (sock_fanout_open(PACKET_FANOUT_CPU, first_group_id) != -1) {
 		fprintf(stderr, "ERROR: joined group with wrong type.\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, first_group_id);
 	if (fds[1] == -1) {
 		fprintf(stderr,
 			"ERROR: failed to join previously created group.\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	fds[2] = sock_fanout_open(PACKET_FANOUT_HASH |
@@ -426,7 +426,7 @@ static void test_unique_fanout_group_ids(void)
 	if (fds[2] == -1) {
 		fprintf(stderr,
 			"ERROR: failed to create a second unique id group.\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	sock_fanout_getopts(fds[2], &typeflags, &second_group_id);
@@ -434,12 +434,12 @@ static void test_unique_fanout_group_ids(void)
 			     second_group_id) != -1) {
 		fprintf(stderr,
 			"ERROR: specified a group id when requesting unique id\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	if (close(fds[0]) || close(fds[1]) || close(fds[2])) {
 		fprintf(stderr, "ERROR: closing sockets\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 }
 
@@ -459,7 +459,7 @@ static int test_datapath(uint16_t typeflags, int port_off,
 	fds[1] = sock_fanout_open(typeflags, 0);
 	if (fds[0] == -1 || fds[1] == -1) {
 		fprintf(stderr, "ERROR: failed open\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 	if (type == PACKET_FANOUT_CBPF)
 		sock_fanout_set_cbpf(fds[0]);
@@ -485,13 +485,13 @@ static int test_datapath(uint16_t typeflags, int port_off,
 	if (munmap(rings[1], RING_NUM_FRAMES * getpagesize()) ||
 	    munmap(rings[0], RING_NUM_FRAMES * getpagesize())) {
 		fprintf(stderr, "close rings\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 	if (close(fds_udp[1][1]) || close(fds_udp[1][0]) ||
 	    close(fds_udp[0][1]) || close(fds_udp[0][0]) ||
 	    close(fds[1]) || close(fds[0])) {
 		fprintf(stderr, "close datapath\n");
-		exit(1);
+		cleanup_and_exit(1);
 	}
 
 	return ret;
@@ -506,7 +506,7 @@ static int set_cpuaffinity(int cpuid)
 	if (sched_setaffinity(0, sizeof(mask), &mask)) {
 		if (errno != EINVAL) {
 			fprintf(stderr, "setaffinity %d\n", cpuid);
-			exit(1);
+			cleanup_and_exit(1);
 		}
 		return 1;
 	}
@@ -569,6 +569,7 @@ int main(int argc, char **argv)
 	ret |= test_datapath(PACKET_FANOUT_FLAG_UNIQUEID, port_off,
 			     expect_uniqueid[0], expect_uniqueid[1]);
 
+	loopback_up_down_restore();
 	if (ret)
 		return 1;
 
-- 
2.45.2

Gur Stavi wrote:
> Minimize the risk that psock_fanout leaves loopback device in a different
> state than the start state.
> 
> Restore loopback up/down state when test reaches end of main.
> For abort on errors, globally replace all 'exit' with 'cleanup_and_exit'
> that restores loopback up/down state.

Luckily tools/testing/selftests/net/run_afpackettests already runs
this test in a network namespace, so nothing terrible will happen if
it leaves lo down on exit.

I'd like to avoid this many code changes. As long as the test exits
with failure, it's fine if this particular state is left.

And prefer separate set_loopback_up and .._down helpers, rather than
a toggle whose behavior depends on current state.

> Signed-off-by: Gur Stavi <gur.stavi@huawei.com>