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author | Willem de Bruijn <willemb@google.com> | 2022-11-28 09:02:10 -0500 |
---|---|---|
committer | Jakub Kicinski <kuba@kernel.org> | 2022-11-29 21:24:32 -0800 |
commit | 91a7de85600d5dfa272cea3cef83052e067dc0ab (patch) | |
tree | 525f9b845140b092fc25e44130484e6fed095775 /tools | |
parent | 5cb0c51fe366cf96b7911d25db3e678401732246 (diff) | |
download | linux-stable-91a7de85600d5dfa272cea3cef83052e067dc0ab.tar.gz linux-stable-91a7de85600d5dfa272cea3cef83052e067dc0ab.tar.bz2 linux-stable-91a7de85600d5dfa272cea3cef83052e067dc0ab.zip |
selftests/net: add csum offload test
Test NIC hardware checksum offload:
- Rx + Tx
- IPv4 + IPv6
- TCP + UDP
Optional features:
- zero checksum 0xFFFF
- checksum disable 0x0000
- transport encap headers
- randomization
See file header for detailed comments.
Expected results differ depending on NIC features:
- CHECKSUM_UNNECESSARY vs CHECKSUM_COMPLETE
- NETIF_F_HW_CSUM (csum_start/csum_off) vs NETIF_F_IP(V6)_CSUM
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20221128140210.553391-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'tools')
-rw-r--r-- | tools/testing/selftests/net/.gitignore | 1 | ||||
-rw-r--r-- | tools/testing/selftests/net/Makefile | 1 | ||||
-rw-r--r-- | tools/testing/selftests/net/csum.c | 986 |
3 files changed, 988 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/.gitignore b/tools/testing/selftests/net/.gitignore index ff8807cc9c2e..ee38ca888244 100644 --- a/tools/testing/selftests/net/.gitignore +++ b/tools/testing/selftests/net/.gitignore @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only bind_bhash +csum cmsg_sender fin_ack_lat gro diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index 880e6ded6ed5..3007e98a6d64 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -74,6 +74,7 @@ TEST_PROGS += test_ingress_egress_chaining.sh TEST_GEN_PROGS += so_incoming_cpu TEST_PROGS += sctp_vrf.sh TEST_GEN_FILES += sctp_hello +TEST_GEN_FILES += csum TEST_FILES := settings diff --git a/tools/testing/selftests/net/csum.c b/tools/testing/selftests/net/csum.c new file mode 100644 index 000000000000..82a1c1839da6 --- /dev/null +++ b/tools/testing/selftests/net/csum.c @@ -0,0 +1,986 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* Test hardware checksum offload: Rx + Tx, IPv4 + IPv6, TCP + UDP. + * + * The test runs on two machines to exercise the NIC. For this reason it + * is not integrated in kselftests. + * + * CMD=$((./csum -[46] -[tu] -S $SADDR -D $DADDR -[RT] -r 1 $EXTRA_ARGS)) + * + * Rx: + * + * The sender sends packets with a known checksum field using PF_INET(6) + * SOCK_RAW sockets. + * + * good packet: $CMD [-t] + * bad packet: $CMD [-t] -E + * + * The receiver reads UDP packets with a UDP socket. This is not an + * option for TCP packets ('-t'). Optionally insert an iptables filter + * to avoid these entering the real protocol stack. + * + * The receiver also reads all packets with a PF_PACKET socket, to + * observe whether both good and bad packets arrive on the host. And to + * read the optional TP_STATUS_CSUM_VALID bit. This requires setting + * option PACKET_AUXDATA, and works only for CHECKSUM_UNNECESSARY. + * + * Tx: + * + * The sender needs to build CHECKSUM_PARTIAL packets to exercise tx + * checksum offload. + * + * The sender can sends packets with a UDP socket. + * + * Optionally crafts a packet that sums up to zero to verify that the + * device writes negative zero 0xFFFF in this case to distinguish from + * 0x0000 (checksum disabled), as required by RFC 768. Hit this case + * by choosing a specific source port. + * + * good packet: $CMD -U + * zero csum: $CMD -U -Z + * + * The sender can also build packets with PF_PACKET with PACKET_VNET_HDR, + * to cover more protocols. PF_PACKET requires passing src and dst mac + * addresses. + * + * good packet: $CMD -s $smac -d $dmac -p [-t] + * + * Argument '-z' sends UDP packets with a 0x000 checksum disabled field, + * to verify that the NIC passes these packets unmodified. + * + * Argument '-e' adds a transport mode encapsulation header between + * network and transport header. This will fail for devices that parse + * headers. Should work on devices that implement protocol agnostic tx + * checksum offload (NETIF_F_HW_CSUM). + * + * Argument '-r $SEED' optionally randomizes header, payload and length + * to increase coverage between packets sent. SEED 1 further chooses a + * different seed for each run (and logs this for reproducibility). It + * is advised to enable this for extra coverage in continuous testing. + */ + +#define _GNU_SOURCE + +#include <arpa/inet.h> +#include <asm/byteorder.h> +#include <errno.h> +#include <error.h> +#include <linux/filter.h> +#include <linux/if_packet.h> +#include <linux/ipv6.h> +#include <linux/virtio_net.h> +#include <net/ethernet.h> +#include <net/if.h> +#include <netinet/if_ether.h> +#include <netinet/in.h> +#include <netinet/ip.h> +#include <netinet/ip6.h> +#include <netinet/tcp.h> +#include <netinet/udp.h> +#include <poll.h> +#include <sched.h> +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/types.h> +#include <unistd.h> + +static bool cfg_bad_csum; +static int cfg_family = PF_INET6; +static int cfg_num_pkt = 4; +static bool cfg_do_rx = true; +static bool cfg_do_tx = true; +static bool cfg_encap; +static char *cfg_ifname = "eth0"; +static char *cfg_mac_dst; +static char *cfg_mac_src; +static int cfg_proto = IPPROTO_UDP; +static int cfg_payload_char = 'a'; +static int cfg_payload_len = 100; +static uint16_t cfg_port_dst = 34000; +static uint16_t cfg_port_src = 33000; +static uint16_t cfg_port_src_encap = 33001; +static unsigned int cfg_random_seed; +static int cfg_rcvbuf = 1 << 22; /* be able to queue large cfg_num_pkt */ +static bool cfg_send_pfpacket; +static bool cfg_send_udp; +static int cfg_timeout_ms = 2000; +static bool cfg_zero_disable; /* skip checksum: set to zero (udp only) */ +static bool cfg_zero_sum; /* create packet that adds up to zero */ + +static struct sockaddr_in cfg_daddr4 = {.sin_family = AF_INET}; +static struct sockaddr_in cfg_saddr4 = {.sin_family = AF_INET}; +static struct sockaddr_in6 cfg_daddr6 = {.sin6_family = AF_INET6}; +static struct sockaddr_in6 cfg_saddr6 = {.sin6_family = AF_INET6}; + +#define ENC_HEADER_LEN (sizeof(struct udphdr) + sizeof(struct udp_encap_hdr)) +#define MAX_HEADER_LEN (sizeof(struct ipv6hdr) + ENC_HEADER_LEN + sizeof(struct tcphdr)) +#define MAX_PAYLOAD_LEN 1024 + +/* Trivial demo encap. Stand-in for transport layer protocols like ESP or PSP */ +struct udp_encap_hdr { + uint8_t nexthdr; + uint8_t padding[3]; +}; + +/* Ipaddrs, for pseudo csum. Global var is ugly, pass through funcs was worse */ +static void *iph_addr_p; + +static unsigned long gettimeofday_ms(void) +{ + struct timeval tv; + + gettimeofday(&tv, NULL); + return (tv.tv_sec * 1000UL) + (tv.tv_usec / 1000UL); +} + +static uint32_t checksum_nofold(char *data, size_t len, uint32_t sum) +{ + uint16_t *words = (uint16_t *)data; + int i; + + for (i = 0; i < len / 2; i++) + sum += words[i]; + + if (len & 1) + sum += ((unsigned char *)data)[len - 1]; + + return sum; +} + +static uint16_t checksum_fold(void *data, size_t len, uint32_t sum) +{ + sum = checksum_nofold(data, len, sum); + + while (sum > 0xFFFF) + sum = (sum & 0xFFFF) + (sum >> 16); + + return ~sum; +} + +static uint16_t checksum(void *th, uint16_t proto, size_t len) +{ + uint32_t sum; + int alen; + + alen = cfg_family == PF_INET6 ? 32 : 8; + + sum = checksum_nofold(iph_addr_p, alen, 0); + sum += htons(proto); + sum += htons(len); + + /* With CHECKSUM_PARTIAL kernel expects non-inverted pseudo csum */ + if (cfg_do_tx && cfg_send_pfpacket) + return ~checksum_fold(NULL, 0, sum); + else + return checksum_fold(th, len, sum); +} + +static void *build_packet_ipv4(void *_iph, uint8_t proto, unsigned int len) +{ + struct iphdr *iph = _iph; + + memset(iph, 0, sizeof(*iph)); + + iph->version = 4; + iph->ihl = 5; + iph->ttl = 8; + iph->protocol = proto; + iph->saddr = cfg_saddr4.sin_addr.s_addr; + iph->daddr = cfg_daddr4.sin_addr.s_addr; + iph->tot_len = htons(sizeof(*iph) + len); + iph->check = checksum_fold(iph, sizeof(*iph), 0); + + iph_addr_p = &iph->saddr; + + return iph + 1; +} + +static void *build_packet_ipv6(void *_ip6h, uint8_t proto, unsigned int len) +{ + struct ipv6hdr *ip6h = _ip6h; + + memset(ip6h, 0, sizeof(*ip6h)); + + ip6h->version = 6; + ip6h->payload_len = htons(len); + ip6h->nexthdr = proto; + ip6h->hop_limit = 64; + ip6h->saddr = cfg_saddr6.sin6_addr; + ip6h->daddr = cfg_daddr6.sin6_addr; + + iph_addr_p = &ip6h->saddr; + + return ip6h + 1; +} + +static void *build_packet_udp(void *_uh) +{ + struct udphdr *uh = _uh; + + uh->source = htons(cfg_port_src); + uh->dest = htons(cfg_port_dst); + uh->len = htons(sizeof(*uh) + cfg_payload_len); + uh->check = 0; + + /* choose source port so that uh->check adds up to zero */ + if (cfg_zero_sum) { + uh->source = 0; + uh->source = checksum(uh, IPPROTO_UDP, sizeof(*uh) + cfg_payload_len); + + fprintf(stderr, "tx: changing sport: %hu -> %hu\n", + cfg_port_src, ntohs(uh->source)); + cfg_port_src = ntohs(uh->source); + } + + if (cfg_zero_disable) + uh->check = 0; + else + uh->check = checksum(uh, IPPROTO_UDP, sizeof(*uh) + cfg_payload_len); + + if (cfg_bad_csum) + uh->check = ~uh->check; + + fprintf(stderr, "tx: sending checksum: 0x%x\n", uh->check); + return uh + 1; +} + +static void *build_packet_tcp(void *_th) +{ + struct tcphdr *th = _th; + + th->source = htons(cfg_port_src); + th->dest = htons(cfg_port_dst); + th->doff = 5; + th->check = 0; + + th->check = checksum(th, IPPROTO_TCP, sizeof(*th) + cfg_payload_len); + + if (cfg_bad_csum) + th->check = ~th->check; + + fprintf(stderr, "tx: sending checksum: 0x%x\n", th->check); + return th + 1; +} + +static char *build_packet_udp_encap(void *_uh) +{ + struct udphdr *uh = _uh; + struct udp_encap_hdr *eh = _uh + sizeof(*uh); + + /* outer dst == inner dst, to simplify BPF filter + * outer src != inner src, to demultiplex on recv + */ + uh->dest = htons(cfg_port_dst); + uh->source = htons(cfg_port_src_encap); + uh->check = 0; + uh->len = htons(sizeof(*uh) + + sizeof(*eh) + + sizeof(struct tcphdr) + + cfg_payload_len); + + eh->nexthdr = IPPROTO_TCP; + + return build_packet_tcp(eh + 1); +} + +static char *build_packet(char *buf, int max_len, int *len) +{ + uint8_t proto; + char *off; + int tlen; + + if (cfg_random_seed) { + int *buf32 = (void *)buf; + int i; + + for (i = 0; i < (max_len / sizeof(int)); i++) + buf32[i] = rand(); + } else { + memset(buf, cfg_payload_char, max_len); + } + + if (cfg_proto == IPPROTO_UDP) + tlen = sizeof(struct udphdr) + cfg_payload_len; + else + tlen = sizeof(struct tcphdr) + cfg_payload_len; + + if (cfg_encap) { + proto = IPPROTO_UDP; + tlen += ENC_HEADER_LEN; + } else { + proto = cfg_proto; + } + + if (cfg_family == PF_INET) + off = build_packet_ipv4(buf, proto, tlen); + else + off = build_packet_ipv6(buf, proto, tlen); + + if (cfg_encap) + off = build_packet_udp_encap(off); + else if (cfg_proto == IPPROTO_UDP) + off = build_packet_udp(off); + else + off = build_packet_tcp(off); + + /* only pass the payload, but still compute headers for cfg_zero_sum */ + if (cfg_send_udp) { + *len = cfg_payload_len; + return off; + } + + *len = off - buf + cfg_payload_len; + return buf; +} + +static int open_inet(int ipproto, int protocol) +{ + int fd; + + fd = socket(cfg_family, ipproto, protocol); + if (fd == -1) + error(1, errno, "socket inet"); + + if (cfg_family == PF_INET6) { + /* may have been updated by cfg_zero_sum */ + cfg_saddr6.sin6_port = htons(cfg_port_src); + + if (bind(fd, (void *)&cfg_saddr6, sizeof(cfg_saddr6))) + error(1, errno, "bind dgram 6"); + if (connect(fd, (void *)&cfg_daddr6, sizeof(cfg_daddr6))) + error(1, errno, "connect dgram 6"); + } else { + /* may have been updated by cfg_zero_sum */ + cfg_saddr4.sin_port = htons(cfg_port_src); + + if (bind(fd, (void *)&cfg_saddr4, sizeof(cfg_saddr4))) + error(1, errno, "bind dgram 4"); + if (connect(fd, (void *)&cfg_daddr4, sizeof(cfg_daddr4))) + error(1, errno, "connect dgram 4"); + } + + return fd; +} + +static int open_packet(void) +{ + int fd, one = 1; + + fd = socket(PF_PACKET, SOCK_RAW, 0); + if (fd == -1) + error(1, errno, "socket packet"); + + if (setsockopt(fd, SOL_PACKET, PACKET_VNET_HDR, &one, sizeof(one))) + error(1, errno, "setsockopt packet_vnet_ndr"); + + return fd; +} + +static void send_inet(int fd, const char *buf, int len) +{ + int ret; + + ret = write(fd, buf, len); + if (ret == -1) + error(1, errno, "write"); + if (ret != len) + error(1, 0, "write: %d", ret); +} + +static void eth_str_to_addr(const char *str, unsigned char *eth) +{ + if (sscanf(str, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", + ð[0], ð[1], ð[2], ð[3], ð[4], ð[5]) != 6) + error(1, 0, "cannot parse mac addr %s", str); +} + +static void send_packet(int fd, const char *buf, int len) +{ + struct virtio_net_hdr vh = {0}; + struct sockaddr_ll addr = {0}; + struct msghdr msg = {0}; + struct ethhdr eth; + struct iovec iov[3]; + int ret; + + addr.sll_family = AF_PACKET; + addr.sll_halen = ETH_ALEN; + addr.sll_ifindex = if_nametoindex(cfg_ifname); + if (!addr.sll_ifindex) + error(1, errno, "if_nametoindex %s", cfg_ifname); + + vh.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; + if (cfg_family == PF_INET6) { + vh.csum_start = sizeof(struct ethhdr) + sizeof(struct ipv6hdr); + addr.sll_protocol = htons(ETH_P_IPV6); + } else { + vh.csum_start = sizeof(struct ethhdr) + sizeof(struct iphdr); + addr.sll_protocol = htons(ETH_P_IP); + } + + if (cfg_encap) + vh.csum_start += ENC_HEADER_LEN; + + if (cfg_proto == IPPROTO_TCP) { + vh.csum_offset = __builtin_offsetof(struct tcphdr, check); + vh.hdr_len = vh.csum_start + sizeof(struct tcphdr); + } else { + vh.csum_offset = __builtin_offsetof(struct udphdr, check); + vh.hdr_len = vh.csum_start + sizeof(struct udphdr); + } + + eth_str_to_addr(cfg_mac_src, eth.h_source); + eth_str_to_addr(cfg_mac_dst, eth.h_dest); + eth.h_proto = addr.sll_protocol; + + iov[0].iov_base = &vh; + iov[0].iov_len = sizeof(vh); + + iov[1].iov_base = ð + iov[1].iov_len = sizeof(eth); + + iov[2].iov_base = (void *)buf; + iov[2].iov_len = len; + + msg.msg_iov = iov; + msg.msg_iovlen = sizeof(iov) / sizeof(iov[0]); + + msg.msg_name = &addr; + msg.msg_namelen = sizeof(addr); + + ret = sendmsg(fd, &msg, 0); + if (ret == -1) + error(1, errno, "sendmsg packet"); + if (ret != sizeof(vh) + sizeof(eth) + len) + error(1, errno, "sendmsg packet: %u", ret); +} + +static int recv_prepare_udp(void) +{ + int fd; + + fd = socket(cfg_family, SOCK_DGRAM, 0); + if (fd == -1) + error(1, errno, "socket r"); + + if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, + &cfg_rcvbuf, sizeof(cfg_rcvbuf))) + error(1, errno, "setsockopt SO_RCVBUF r"); + + if (cfg_family == PF_INET6) { + if (bind(fd, (void *)&cfg_daddr6, sizeof(cfg_daddr6))) + error(1, errno, "bind r"); + } else { + if (bind(fd, (void *)&cfg_daddr4, sizeof(cfg_daddr4))) + error(1, errno, "bind r"); + } + + return fd; +} + +/* Filter out all traffic that is not cfg_proto with our destination port. + * + * Otherwise background noise may cause PF_PACKET receive queue overflow, + * dropping the expected packets and failing the test. + */ +static void __recv_prepare_packet_filter(int fd, int off_nexthdr, int off_dport) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD + BPF_B + BPF_ABS, SKF_AD_OFF + SKF_AD_PKTTYPE), + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, PACKET_HOST, 0, 4), + BPF_STMT(BPF_LD + BPF_B + BPF_ABS, off_nexthdr), + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, cfg_encap ? IPPROTO_UDP : cfg_proto, 0, 2), + BPF_STMT(BPF_LD + BPF_H + BPF_ABS, off_dport), + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, cfg_port_dst, 1, 0), + BPF_STMT(BPF_RET + BPF_K, 0), + BPF_STMT(BPF_RET + BPF_K, 0xFFFF), + }; + struct sock_fprog prog = {}; + + prog.filter = filter; + prog.len = sizeof(filter) / sizeof(struct sock_filter); + if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &prog, sizeof(prog))) + error(1, errno, "setsockopt filter"); +} + +static void recv_prepare_packet_filter(int fd) +{ + const int off_dport = offsetof(struct tcphdr, dest); /* same for udp */ + + if (cfg_family == AF_INET) + __recv_prepare_packet_filter(fd, offsetof(struct iphdr, protocol), + sizeof(struct iphdr) + off_dport); + else + __recv_prepare_packet_filter(fd, offsetof(struct ipv6hdr, nexthdr), + sizeof(struct ipv6hdr) + off_dport); +} + +static void recv_prepare_packet_bind(int fd) +{ + struct sockaddr_ll laddr = {0}; + + laddr.sll_family = AF_PACKET; + + if (cfg_family == PF_INET) + laddr.sll_protocol = htons(ETH_P_IP); + else + laddr.sll_protocol = htons(ETH_P_IPV6); + + laddr.sll_ifindex = if_nametoindex(cfg_ifname); + if (!laddr.sll_ifindex) + error(1, 0, "if_nametoindex %s", cfg_ifname); + + if (bind(fd, (void *)&laddr, sizeof(laddr))) + error(1, errno, "bind pf_packet"); +} + +static int recv_prepare_packet(void) +{ + int fd, one = 1; + + fd = socket(PF_PACKET, SOCK_DGRAM, 0); + if (fd == -1) + error(1, errno, "socket p"); + + if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, + &cfg_rcvbuf, sizeof(cfg_rcvbuf))) + error(1, errno, "setsockopt SO_RCVBUF p"); + + /* enable auxdata to recv checksum status (valid vs unknown) */ + if (setsockopt(fd, SOL_PACKET, PACKET_AUXDATA, &one, sizeof(one))) + error(1, errno, "setsockopt auxdata"); + + /* install filter to restrict packet flow to match */ + recv_prepare_packet_filter(fd); + + /* bind to address family to start packet flow */ + recv_prepare_packet_bind(fd); + + return fd; +} + +static int recv_udp(int fd) +{ + static char buf[MAX_PAYLOAD_LEN]; + int ret, count = 0; + + while (1) { + ret = recv(fd, buf, sizeof(buf), MSG_DONTWAIT); + if (ret == -1 && errno == EAGAIN) + break; + if (ret == -1) + error(1, errno, "recv r"); + + fprintf(stderr, "rx: udp: len=%u\n", ret); + count++; + } + + return count; +} + +static int recv_verify_csum(void *th, int len, uint16_t sport, uint16_t csum_field) +{ + uint16_t csum; + + csum = checksum(th, cfg_proto, len); + + fprintf(stderr, "rx: pkt: sport=%hu len=%u csum=0x%hx verify=0x%hx\n", + sport, len, csum_field, csum); + + /* csum must be zero unless cfg_bad_csum indicates bad csum */ + if (csum && !cfg_bad_csum) { + fprintf(stderr, "pkt: bad csum\n"); + return 1; + } else if (cfg_bad_csum && !csum) { + fprintf(stderr, "pkt: good csum, while bad expected\n"); + return 1; + } + + if (cfg_zero_sum && csum_field != 0xFFFF) { + fprintf(stderr, "pkt: zero csum: field should be 0xFFFF, is 0x%hx\n", csum_field); + return 1; + } + + return 0; +} + +static int recv_verify_packet_tcp(void *th, int len) +{ + struct tcphdr *tcph = th; + + if (len < sizeof(*tcph) || tcph->dest != htons(cfg_port_dst)) + return -1; + + return recv_verify_csum(th, len, ntohs(tcph->source), tcph->check); +} + +static int recv_verify_packet_udp_encap(void *th, int len) +{ + struct udp_encap_hdr *eh = th; + + if (len < sizeof(*eh) || eh->nexthdr != IPPROTO_TCP) + return -1; + + return recv_verify_packet_tcp(eh + 1, len - sizeof(*eh)); +} + +static int recv_verify_packet_udp(void *th, int len) +{ + struct udphdr *udph = th; + + if (len < sizeof(*udph)) + return -1; + + if (udph->dest != htons(cfg_port_dst)) + return -1; + + if (udph->source == htons(cfg_port_src_encap)) + return recv_verify_packet_udp_encap(udph + 1, + len - sizeof(*udph)); + + return recv_verify_csum(th, len, ntohs(udph->source), udph->check); +} + +static int recv_verify_packet_ipv4(void *nh, int len) +{ + struct iphdr *iph = nh; + uint16_t proto = cfg_encap ? IPPROTO_UDP : cfg_proto; + + if (len < sizeof(*iph) || iph->protocol != proto) + return -1; + + iph_addr_p = &iph->saddr; + if (proto == IPPROTO_TCP) + return recv_verify_packet_tcp(iph + 1, len - sizeof(*iph)); + else + return recv_verify_packet_udp(iph + 1, len - sizeof(*iph)); +} + +static int recv_verify_packet_ipv6(void *nh, int len) +{ + struct ipv6hdr *ip6h = nh; + uint16_t proto = cfg_encap ? IPPROTO_UDP : cfg_proto; + + if (len < sizeof(*ip6h) || ip6h->nexthdr != proto) + return -1; + + iph_addr_p = &ip6h->saddr; + + if (proto == IPPROTO_TCP) + return recv_verify_packet_tcp(ip6h + 1, len - sizeof(*ip6h)); + else + return recv_verify_packet_udp(ip6h + 1, len - sizeof(*ip6h)); +} + +/* return whether auxdata includes TP_STATUS_CSUM_VALID */ +static bool recv_verify_packet_csum(struct msghdr *msg) +{ + struct tpacket_auxdata *aux = NULL; + struct cmsghdr *cm; + + if (msg->msg_flags & MSG_CTRUNC) + error(1, 0, "cmsg: truncated"); + + for (cm = CMSG_FIRSTHDR(msg); cm; cm = CMSG_NXTHDR(msg, cm)) { + if (cm->cmsg_level != SOL_PACKET || + cm->cmsg_type != PACKET_AUXDATA) + error(1, 0, "cmsg: level=%d type=%d\n", + cm->cmsg_level, cm->cmsg_type); + + if (cm->cmsg_len != CMSG_LEN(sizeof(struct tpacket_auxdata))) + error(1, 0, "cmsg: len=%lu expected=%lu", + cm->cmsg_len, CMSG_LEN(sizeof(struct tpacket_auxdata))); + + aux = (void *)CMSG_DATA(cm); + } + + if (!aux) + error(1, 0, "cmsg: no auxdata"); + + return aux->tp_status & TP_STATUS_CSUM_VALID; +} + +static int recv_packet(int fd) +{ + static char _buf[MAX_HEADER_LEN + MAX_PAYLOAD_LEN]; + unsigned long total = 0, bad_csums = 0, bad_validations = 0; + char ctrl[CMSG_SPACE(sizeof(struct tpacket_auxdata))]; + struct pkt *buf = (void *)_buf; + struct msghdr msg = {0}; + struct iovec iov; + int len, ret; + + iov.iov_base = _buf; + iov.iov_len = sizeof(_buf); + + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + + msg.msg_control = ctrl; + msg.msg_controllen = sizeof(ctrl); + + while (1) { + msg.msg_flags = 0; + + len = recvmsg(fd, &msg, MSG_DONTWAIT); + if (len == -1 && errno == EAGAIN) + break; + if (len == -1) + error(1, errno, "recv p"); + + if (cfg_family == PF_INET6) + ret = recv_verify_packet_ipv6(buf, len); + else + ret = recv_verify_packet_ipv4(buf, len); + + if (ret == -1 /* skip: non-matching */) + continue; + + total++; + if (ret == 1) + bad_csums++; + + /* Fail if kernel returns valid for known bad csum. + * Do not fail if kernel does not validate a good csum: + * Absence of validation does not imply invalid. + */ + if (recv_verify_packet_csum(&msg) && cfg_bad_csum) { + fprintf(stderr, "cmsg: expected bad csum, pf_packet returns valid\n"); + bad_validations++; + } + } + + if (bad_csums || bad_validations) + error(1, 0, "rx: errors at pf_packet: total=%lu bad_csums=%lu bad_valids=%lu\n", + total, bad_csums, bad_validations); + + return total; +} + +static void parse_args(int argc, char *const argv[]) +{ + const char *daddr = NULL, *saddr = NULL; + int c; + + while ((c = getopt(argc, argv, "46d:D:eEi:l:L:n:r:PRs:S:tTuUzZ")) != -1) { + switch (c) { + case '4': + cfg_family = PF_INET; + break; + case '6': + cfg_family = PF_INET6; + break; + case 'd': + cfg_mac_dst = optarg; + break; + case 'D': + daddr = optarg; + break; + case 'e': + cfg_encap = true; + break; + case 'E': + cfg_bad_csum = true; + break; + case 'i': + cfg_ifname = optarg; + break; + case 'l': + cfg_payload_len = strtol(optarg, NULL, 0); + break; + case 'L': + cfg_timeout_ms = strtol(optarg, NULL, 0) * 1000; + break; + case 'n': + cfg_num_pkt = strtol(optarg, NULL, 0); + break; + case 'r': + cfg_random_seed = strtol(optarg, NULL, 0); + break; + case 'P': + cfg_send_pfpacket = true; + break; + case 'R': + /* only Rx: used with two machine tests */ + cfg_do_tx = false; + break; + case 's': + cfg_mac_src = optarg; + break; + case 'S': + saddr = optarg; + break; + case 't': + cfg_proto = IPPROTO_TCP; + break; + case 'T': + /* only Tx: used with two machine tests */ + cfg_do_rx = false; + break; + case 'u': + cfg_proto = IPPROTO_UDP; + break; + case 'U': + /* send using real udp socket, + * to exercise tx checksum offload + */ + cfg_send_udp = true; + break; + case 'z': + cfg_zero_disable = true; + break; + case 'Z': + cfg_zero_sum = true; + break; + default: + error(1, 0, "unknown arg %c", c); + } + } + + if (!daddr || !saddr) + error(1, 0, "Must pass -D <daddr> and -S <saddr>"); + + if (cfg_do_tx && cfg_send_pfpacket && (!cfg_mac_src || !cfg_mac_dst)) + error(1, 0, "Transmit with pf_packet requires mac addresses"); + + if (cfg_payload_len > MAX_PAYLOAD_LEN) + error(1, 0, "Payload length exceeds max"); + + if (cfg_proto != IPPROTO_UDP && (cfg_zero_sum || cfg_zero_disable)) + error(1, 0, "Only UDP supports zero csum"); + + if (cfg_zero_sum && !cfg_send_udp) + error(1, 0, "Zero checksum conversion requires -U for tx csum offload"); + if (cfg_zero_sum && cfg_bad_csum) + error(1, 0, "Cannot combine zero checksum conversion and invalid checksum"); + if (cfg_zero_sum && cfg_random_seed) + error(1, 0, "Cannot combine zero checksum conversion with randomization"); + + if (cfg_family == PF_INET6) { + cfg_saddr6.sin6_port = htons(cfg_port_src); + cfg_daddr6.sin6_port = htons(cfg_port_dst); + + if (inet_pton(cfg_family, daddr, &cfg_daddr6.sin6_addr) != 1) + error(1, errno, "Cannot parse ipv6 -D"); + if (inet_pton(cfg_family, saddr, &cfg_saddr6.sin6_addr) != 1) + error(1, errno, "Cannot parse ipv6 -S"); + } else { + cfg_saddr4.sin_port = htons(cfg_port_src); + cfg_daddr4.sin_port = htons(cfg_port_dst); + + if (inet_pton(cfg_family, daddr, &cfg_daddr4.sin_addr) != 1) + error(1, errno, "Cannot parse ipv4 -D"); + if (inet_pton(cfg_family, saddr, &cfg_saddr4.sin_addr) != 1) + error(1, errno, "Cannot parse ipv4 -S"); + } + + if (cfg_do_tx && cfg_random_seed) { + /* special case: time-based seed */ + if (cfg_random_seed == 1) + cfg_random_seed = (unsigned int)gettimeofday_ms(); + srand(cfg_random_seed); + fprintf(stderr, "randomization seed: %u\n", cfg_random_seed); + } +} + +static void do_tx(void) +{ + static char _buf[MAX_HEADER_LEN + MAX_PAYLOAD_LEN]; + char *buf; + int fd, len, i; + + buf = build_packet(_buf, sizeof(_buf), &len); + + if (cfg_send_pfpacket) + fd = open_packet(); + else if (cfg_send_udp) + fd = open_inet(SOCK_DGRAM, 0); + else + fd = open_inet(SOCK_RAW, IPPROTO_RAW); + + for (i = 0; i < cfg_num_pkt; i++) { + if (cfg_send_pfpacket) + send_packet(fd, buf, len); + else + send_inet(fd, buf, len); + + /* randomize each packet individually to increase coverage */ + if (cfg_random_seed) { + cfg_payload_len = rand() % MAX_PAYLOAD_LEN; + buf = build_packet(_buf, sizeof(_buf), &len); + } + } + + if (close(fd)) + error(1, errno, "close tx"); +} + +static void do_rx(int fdp, int fdr) +{ + unsigned long count_udp = 0, count_pkt = 0; + long tleft, tstop; + struct pollfd pfd; + + tstop = gettimeofday_ms() + cfg_timeout_ms; + tleft = cfg_timeout_ms; + + do { + pfd.events = POLLIN; + pfd.fd = fdp; + if (poll(&pfd, 1, tleft) == -1) + error(1, errno, "poll"); + + if (pfd.revents & POLLIN) + count_pkt += recv_packet(fdp); + + if (cfg_proto == IPPROTO_UDP) + count_udp += recv_udp(fdr); + + tleft = tstop - gettimeofday_ms(); + } while (tleft > 0); + + if (close(fdr)) + error(1, errno, "close r"); + if (close(fdp)) + error(1, errno, "close p"); + + if (count_pkt < cfg_num_pkt) + error(1, 0, "rx: missing packets at pf_packet: %lu < %u", + count_pkt, cfg_num_pkt); + + if (cfg_proto == IPPROTO_UDP) { + if (cfg_bad_csum && count_udp) + error(1, 0, "rx: unexpected packets at udp"); + if (!cfg_bad_csum && !count_udp) + error(1, 0, "rx: missing packets at udp"); + } +} + +int main(int argc, char *const argv[]) +{ + int fdp = -1, fdr = -1; /* -1 to silence -Wmaybe-uninitialized */ + + parse_args(argc, argv); + + /* open receive sockets before transmitting */ + if (cfg_do_rx) { + fdp = recv_prepare_packet(); + fdr = recv_prepare_udp(); + } + + if (cfg_do_tx) + do_tx(); + + if (cfg_do_rx) + do_rx(fdp, fdr); + + fprintf(stderr, "OK\n"); + return 0; +} |