// SPDX-License-Identifier: GPL-2.0 /* * This tests the blackhole_dev that is created during the * net subsystem initialization. The test this module performs is * by injecting an skb into the stack with skb->dev as the * blackhole_dev and expects kernel to behave in a sane manner * (in other words, *not crash*)! * * Copyright (c) 2018, Mahesh Bandewar <maheshb@google.com> */ #include <kunit/test.h> #include <linux/module.h> #include <linux/skbuff.h> #include <linux/netdevice.h> #include <linux/udp.h> #include <linux/ipv6.h> #include <net/dst.h> #define SKB_SIZE 256 #define HEAD_SIZE (14+40+8) /* Ether + IPv6 + UDP */ #define TAIL_SIZE 32 /* random tail-room */ #define UDP_PORT 1234 static void test_blackholedev(struct kunit *test) { struct ipv6hdr *ip6h; struct sk_buff *skb; struct udphdr *uh; int data_len; skb = alloc_skb(SKB_SIZE, GFP_KERNEL); KUNIT_ASSERT_NOT_NULL(test, skb); /* Reserve head-room for the headers */ skb_reserve(skb, HEAD_SIZE); /* Add data to the skb */ data_len = SKB_SIZE - (HEAD_SIZE + TAIL_SIZE); memset(__skb_put(skb, data_len), 0xf, data_len); /* Add protocol data */ /* (Transport) UDP */ uh = (struct udphdr *)skb_push(skb, sizeof(struct udphdr)); skb_set_transport_header(skb, 0); uh->source = uh->dest = htons(UDP_PORT); uh->len = htons(data_len); uh->check = 0; /* (Network) IPv6 */ ip6h = (struct ipv6hdr *)skb_push(skb, sizeof(struct ipv6hdr)); skb_set_network_header(skb, 0); ip6h->hop_limit = 32; ip6h->payload_len = htons(data_len + sizeof(struct udphdr)); ip6h->nexthdr = IPPROTO_UDP; ip6h->saddr = in6addr_loopback; ip6h->daddr = in6addr_loopback; /* Ether */ skb_push(skb, sizeof(struct ethhdr)); skb_set_mac_header(skb, 0); skb->protocol = htons(ETH_P_IPV6); skb->pkt_type = PACKET_HOST; skb->dev = blackhole_netdev; /* Now attempt to send the packet */ KUNIT_EXPECT_EQ(test, dev_queue_xmit(skb), NET_XMIT_SUCCESS); } static struct kunit_case blackholedev_cases[] = { KUNIT_CASE(test_blackholedev), {}, }; static struct kunit_suite blackholedev_suite = { .name = "blackholedev", .test_cases = blackholedev_cases, }; kunit_test_suite(blackholedev_suite); MODULE_AUTHOR("Mahesh Bandewar <maheshb@google.com>"); MODULE_DESCRIPTION("module test of the blackhole_dev"); MODULE_LICENSE("GPL");