From 358be656406dce296fafeac7a913ba33e9a66971 Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Sat, 24 Nov 2018 21:09:26 -0500 Subject: selftests/net: add txring_overwrite Packet sockets with PACKET_TX_RING send skbs with user data in frags. Before commit 5cd8d46ea156 ("packet: copy user buffers before orphan or clone") ring slots could be released prematurely, possibly allowing a process to overwrite data still in flight. This test opens two packet sockets, one to send and one to read. The sender has a tx ring of one slot. It sends two packets with different payload, then reads both and verifies their payload. Before the above commit, both receive calls return the same data as the send calls use the same buffer. From the commit, the clone needed for looping onto a packet socket triggers an skb_copy_ubufs to create a private copy. The separate sends each arrive correctly. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller --- tools/testing/selftests/net/.gitignore | 1 + tools/testing/selftests/net/Makefile | 2 +- tools/testing/selftests/net/run_afpackettests | 10 ++ tools/testing/selftests/net/txring_overwrite.c | 179 +++++++++++++++++++++++++ 4 files changed, 191 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/net/txring_overwrite.c (limited to 'tools/testing/selftests') diff --git a/tools/testing/selftests/net/.gitignore b/tools/testing/selftests/net/.gitignore index 8cf22b3c2563..7f57b916e6b2 100644 --- a/tools/testing/selftests/net/.gitignore +++ b/tools/testing/selftests/net/.gitignore @@ -14,4 +14,5 @@ udpgso_bench_rx udpgso_bench_tx tcp_inq tls +txring_overwrite ip_defrag diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index eec359895feb..7aebbcaa91bf 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -11,7 +11,7 @@ TEST_PROGS += udpgro_bench.sh udpgro.sh TEST_PROGS_EXTENDED := in_netns.sh TEST_GEN_FILES = socket TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy -TEST_GEN_FILES += tcp_mmap tcp_inq psock_snd +TEST_GEN_FILES += tcp_mmap tcp_inq psock_snd txring_overwrite TEST_GEN_FILES += udpgso udpgso_bench_tx udpgso_bench_rx ip_defrag TEST_GEN_PROGS = reuseport_bpf reuseport_bpf_cpu reuseport_bpf_numa TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict tls diff --git a/tools/testing/selftests/net/run_afpackettests b/tools/testing/selftests/net/run_afpackettests index bea079edc278..2dc95fda7ef7 100755 --- a/tools/testing/selftests/net/run_afpackettests +++ b/tools/testing/selftests/net/run_afpackettests @@ -25,3 +25,13 @@ if [ $? -ne 0 ]; then else echo "[PASS]" fi + +echo "--------------------" +echo "running txring_overwrite test" +echo "--------------------" +./in_netns.sh ./txring_overwrite +if [ $? -ne 0 ]; then + echo "[FAIL]" +else + echo "[PASS]" +fi diff --git a/tools/testing/selftests/net/txring_overwrite.c b/tools/testing/selftests/net/txring_overwrite.c new file mode 100644 index 000000000000..fd8b1c663c39 --- /dev/null +++ b/tools/testing/selftests/net/txring_overwrite.c @@ -0,0 +1,179 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Verify that consecutive sends over packet tx_ring are mirrored + * with their original content intact. + */ + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +const int eth_off = TPACKET_HDRLEN - sizeof(struct sockaddr_ll); +const int cfg_frame_size = 1000; + +static void build_packet(void *buffer, size_t blen, char payload_char) +{ + struct udphdr *udph; + struct ethhdr *eth; + struct iphdr *iph; + size_t off = 0; + + memset(buffer, 0, blen); + + eth = buffer; + eth->h_proto = htons(ETH_P_IP); + + off += sizeof(*eth); + iph = buffer + off; + iph->ttl = 8; + iph->ihl = 5; + iph->version = 4; + iph->saddr = htonl(INADDR_LOOPBACK); + iph->daddr = htonl(INADDR_LOOPBACK + 1); + iph->protocol = IPPROTO_UDP; + iph->tot_len = htons(blen - off); + iph->check = 0; + + off += sizeof(*iph); + udph = buffer + off; + udph->dest = htons(8000); + udph->source = htons(8001); + udph->len = htons(blen - off); + udph->check = 0; + + off += sizeof(*udph); + memset(buffer + off, payload_char, blen - off); +} + +static int setup_rx(void) +{ + int fdr; + + fdr = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_IP)); + if (fdr == -1) + error(1, errno, "socket r"); + + return fdr; +} + +static int setup_tx(char **ring) +{ + struct sockaddr_ll laddr = {}; + struct tpacket_req req = {}; + int fdt; + + fdt = socket(PF_PACKET, SOCK_RAW, 0); + if (fdt == -1) + error(1, errno, "socket t"); + + laddr.sll_family = AF_PACKET; + laddr.sll_protocol = htons(0); + laddr.sll_ifindex = if_nametoindex("lo"); + if (!laddr.sll_ifindex) + error(1, errno, "if_nametoindex"); + + if (bind(fdt, (void *)&laddr, sizeof(laddr))) + error(1, errno, "bind fdt"); + + req.tp_block_size = getpagesize(); + req.tp_block_nr = 1; + req.tp_frame_size = getpagesize(); + req.tp_frame_nr = 1; + + if (setsockopt(fdt, SOL_PACKET, PACKET_TX_RING, + (void *)&req, sizeof(req))) + error(1, errno, "setsockopt ring"); + + *ring = mmap(0, req.tp_block_size * req.tp_block_nr, + PROT_READ | PROT_WRITE, MAP_SHARED, fdt, 0); + if (!*ring) + error(1, errno, "mmap"); + + return fdt; +} + +static void send_pkt(int fdt, void *slot, char payload_char) +{ + struct tpacket_hdr *header = slot; + int ret; + + while (header->tp_status != TP_STATUS_AVAILABLE) + usleep(1000); + + build_packet(slot + eth_off, cfg_frame_size, payload_char); + + header->tp_len = cfg_frame_size; + header->tp_status = TP_STATUS_SEND_REQUEST; + + ret = sendto(fdt, NULL, 0, 0, NULL, 0); + if (ret == -1) + error(1, errno, "kick tx"); +} + +static int read_verify_pkt(int fdr, char payload_char) +{ + char buf[100]; + int ret; + + ret = read(fdr, buf, sizeof(buf)); + if (ret != sizeof(buf)) + error(1, errno, "read"); + + if (buf[60] != payload_char) { + printf("wrong pattern: 0x%x != 0x%x\n", buf[60], payload_char); + return 1; + } + + printf("read: %c (0x%x)\n", buf[60], buf[60]); + return 0; +} + +int main(int argc, char **argv) +{ + const char payload_patterns[] = "ab"; + char *ring; + int fdr, fdt, ret = 0; + + fdr = setup_rx(); + fdt = setup_tx(&ring); + + send_pkt(fdt, ring, payload_patterns[0]); + send_pkt(fdt, ring, payload_patterns[1]); + + ret |= read_verify_pkt(fdr, payload_patterns[0]); + ret |= read_verify_pkt(fdr, payload_patterns[1]); + + if (close(fdt)) + error(1, errno, "close t"); + if (close(fdr)) + error(1, errno, "close r"); + + return ret; +} -- cgit v1.2.3-59-g8ed1b