/*
 * Copyright 2013 Red Hat, Inc.
 * Author: Daniel Borkmann <dborkman@redhat.com>
 *         Chetan Loke <loke.chetan@gmail.com> (TPACKET_V3 usage example)
 *
 * A basic test of packet socket's TPACKET_V1/TPACKET_V2/TPACKET_V3 behavior.
 *
 * Control:
 *   Test the setup of the TPACKET socket with different patterns that are
 *   known to fail (TODO) resp. succeed (OK).
 *
 * Datapath:
 *   Open a pair of packet sockets and send resp. receive an a priori known
 *   packet pattern accross the sockets and check if it was received resp.
 *   sent correctly. Fanout in combination with RX_RING is currently not
 *   tested here.
 *
 *   The test currently runs for
 *   - TPACKET_V1: RX_RING, TX_RING
 *   - TPACKET_V2: RX_RING, TX_RING
 *   - TPACKET_V3: RX_RING
 *
 * License (GPLv2):
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/mman.h>
#include <linux/if_packet.h>
#include <linux/filter.h>
#include <ctype.h>
#include <fcntl.h>
#include <unistd.h>
#include <bits/wordsize.h>
#include <net/ethernet.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include <net/if.h>
#include <inttypes.h>
#include <poll.h>

#include "psock_lib.h"

#ifndef bug_on
# define bug_on(cond)           assert(!(cond))
#endif

#ifndef __aligned_tpacket
# define __aligned_tpacket      __attribute__((aligned(TPACKET_ALIGNMENT)))
#endif

#ifndef __align_tpacket
# define __align_tpacket(x)     __attribute__((aligned(TPACKET_ALIGN(x))))
#endif

#define NUM_PACKETS             100
#define ALIGN_8(x)              (((x) + 8 - 1) & ~(8 - 1))

struct ring {
        struct iovec *rd;
        uint8_t *mm_space;
        size_t mm_len, rd_len;
        struct sockaddr_ll ll;
        void (*walk)(int sock, struct ring *ring);
        int type, rd_num, flen, version;
        union {
                struct tpacket_req  req;
                struct tpacket_req3 req3;
        };
};

struct block_desc {
        uint32_t version;
        uint32_t offset_to_priv;
        struct tpacket_hdr_v1 h1;
};

union frame_map {
        struct {
                struct tpacket_hdr tp_h __aligned_tpacket;
                struct sockaddr_ll s_ll __align_tpacket(sizeof(struct tpacket_hdr));
        } *v1;
        struct {
                struct tpacket2_hdr tp_h __aligned_tpacket;
                struct sockaddr_ll s_ll __align_tpacket(sizeof(struct tpacket2_hdr));
        } *v2;
        void *raw;
};

static unsigned int total_packets, total_bytes;

static int pfsocket(int ver)
{
        int ret, sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
        if (sock == -1) {
                perror("socket");
                exit(1);
        }

        ret = setsockopt(sock, SOL_PACKET, PACKET_VERSION, &ver, sizeof(ver));
        if (ret == -1) {
                perror("setsockopt");
                exit(1);
        }

        return sock;
}

static void status_bar_update(void)
{
        if (total_packets % 10 == 0) {
                fprintf(stderr, ".");
                fflush(stderr);
        }
}

static void test_payload(void *pay, size_t len)
{
        struct ethhdr *eth = pay;

        if (len < sizeof(struct ethhdr)) {
                fprintf(stderr, "test_payload: packet too "
                        "small: %zu bytes!\n", len);
                exit(1);
        }

        if (eth->h_proto != htons(ETH_P_IP)) {
                fprintf(stderr, "test_payload: wrong ethernet "
                        "type: 0x%x!\n", ntohs(eth->h_proto));
                exit(1);
        }
}

static void create_payload(void *pay, size_t *len)
{
        int i;
        struct ethhdr *eth = pay;
        struct iphdr *ip = pay + sizeof(*eth);

        /* Lets create some broken crap, that still passes
         * our BPF filter.
         */

        *len = DATA_LEN + 42;

        memset(pay, 0xff, ETH_ALEN * 2);
        eth->h_proto = htons(ETH_P_IP);

        for (i = 0; i < sizeof(*ip); ++i)
                ((uint8_t *) pay)[i + sizeof(*eth)] = (uint8_t) rand();

        ip->ihl = 5;
        ip->version = 4;
        ip->protocol = 0x11;
        ip->frag_off = 0;
        ip->ttl = 64;
        ip->tot_len = htons((uint16_t) *len - sizeof(*eth));

        ip->saddr = htonl(INADDR_LOOPBACK);
        ip->daddr = htonl(INADDR_LOOPBACK);

        memset(pay + sizeof(*eth) + sizeof(*ip),
               DATA_CHAR, DATA_LEN);
}

static inline int __v1_rx_kernel_ready(struct tpacket_hdr *hdr)
{
        return ((hdr->tp_status & TP_STATUS_USER) == TP_STATUS_USER);
}

static inline void __v1_rx_user_ready(struct tpacket_hdr *hdr)
{
        hdr->tp_status = TP_STATUS_KERNEL;
        __sync_synchronize();
}

static inline int __v2_rx_kernel_ready(struct tpacket2_hdr *hdr)
{
        return ((hdr->tp_status & TP_STATUS_USER) == TP_STATUS_USER);
}

static inline void __v2_rx_user_ready(struct tpacket2_hdr *hdr)
{
        hdr->tp_status = TP_STATUS_KERNEL;
        __sync_synchronize();
}

static inline int __v1_v2_rx_kernel_ready(void *base, int version)
{
        switch (version) {
        case TPACKET_V1:
                return __v1_rx_kernel_ready(base);
        case TPACKET_V2:
                return __v2_rx_kernel_ready(base);
        default:
                bug_on(1);
                return 0;
        }
}

static inline void __v1_v2_rx_user_ready(void *base, int version)
{
        switch (version) {
        case TPACKET_V1:
                __v1_rx_user_ready(base);
                break;
        case TPACKET_V2:
                __v2_rx_user_ready(base);
                break;
        }
}

static void walk_v1_v2_rx(int sock, struct ring *ring)
{
        struct pollfd pfd;
        int udp_sock[2];
        union frame_map ppd;
        unsigned int frame_num = 0;

        bug_on(ring->type != PACKET_RX_RING);

        pair_udp_open(udp_sock, PORT_BASE);
        pair_udp_setfilter(sock);

        memset(&pfd, 0, sizeof(pfd));
        pfd.fd = sock;
        pfd.events = POLLIN | POLLERR;
        pfd.revents = 0;

        pair_udp_send(udp_sock, NUM_PACKETS);

        while (total_packets < NUM_PACKETS * 2) {
                while (__v1_v2_rx_kernel_ready(ring->rd[frame_num].iov_base,
                                               ring->version)) {
                        ppd.raw = ring->rd[frame_num].iov_base;

                        switch (ring->version) {
                        case TPACKET_V1:
                                test_payload((uint8_t *) ppd.raw + ppd.v1->tp_h.tp_mac,
                                             ppd.v1->tp_h.tp_snaplen);
                                total_bytes += ppd.v1->tp_h.tp_snaplen;
                                break;

                        case TPACKET_V2:
                                test_payload((uint8_t *) ppd.raw + ppd.v2->tp_h.tp_mac,
                                             ppd.v2->tp_h.tp_snaplen);
                                total_bytes += ppd.v2->tp_h.tp_snaplen;
                                break;
                        }

                        status_bar_update();
                        total_packets++;

                        __v1_v2_rx_user_ready(ppd.raw, ring->version);

                        frame_num = (frame_num + 1) % ring->rd_num;
                }

                poll(&pfd, 1, 1);
        }

        pair_udp_close(udp_sock);

        if (total_packets != 2 * NUM_PACKETS) {
                fprintf(stderr, "walk_v%d_rx: received %u out of %u pkts\n",
                        ring->version, total_packets, NUM_PACKETS);
                exit(1);
        }

        fprintf(stderr, " %u pkts (%u bytes)", NUM_PACKETS, total_bytes >> 1);
}

static inline int __v1_tx_kernel_ready(struct tpacket_hdr *hdr)
{
        return !(hdr->tp_status & (TP_STATUS_SEND_REQUEST | TP_STATUS_SENDING));
}

static inline void __v1_tx_user_ready(struct tpacket_hdr *hdr)
{
        hdr->tp_status = TP_STATUS_SEND_REQUEST;
        __sync_synchronize();
}

static inline int __v2_tx_kernel_ready(struct tpacket2_hdr *hdr)
{
        return !(hdr->tp_status & (TP_STATUS_SEND_REQUEST | TP_STATUS_SENDING));
}

static inline void __v2_tx_user_ready(struct tpacket2_hdr *hdr)
{
        hdr->tp_status = TP_STATUS_SEND_REQUEST;
        __sync_synchronize();
}

static inline int __v1_v2_tx_kernel_ready(void *base, int version)
{
        switch (version) {
        case TPACKET_V1:
                return __v1_tx_kernel_ready(base);
        case TPACKET_V2:
                return __v2_tx_kernel_ready(base);
        default:
                bug_on(1);
                return 0;
        }
}

static inline void __v1_v2_tx_user_ready(void *base, int version)
{
        switch (version) {
        case TPACKET_V1:
                __v1_tx_user_ready(base);
                break;
        case TPACKET_V2:
                __v2_tx_user_ready(base);
                break;
        }
}

static void __v1_v2_set_packet_loss_discard(int sock)
{
        int ret, discard = 1;

        ret = setsockopt(sock, SOL_PACKET, PACKET_LOSS, (void *) &discard,
                         sizeof(discard));
        if (ret == -1) {
                perror("setsockopt");
                exit(1);
        }
}

static void walk_v1_v2_tx(int sock, struct ring *ring)
{
        struct pollfd pfd;
        int rcv_sock, ret;
        size_t packet_len;
        union frame_map ppd;
        char packet[1024];
        unsigned int frame_num = 0, got = 0;
        struct sockaddr_ll ll = {
                .sll_family = PF_PACKET,
                .sll_halen = ETH_ALEN,
        };

        bug_on(ring->type != PACKET_TX_RING);
        bug_on(ring->rd_num < NUM_PACKETS);

        rcv_sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
        if (rcv_sock == -1) {
                perror("socket");
                exit(1);
        }

        pair_udp_setfilter(rcv_sock);

        ll.sll_ifindex = if_nametoindex("lo");
        ret = bind(rcv_sock, (struct sockaddr *) &ll, sizeof(ll));
        if (ret == -1) {
                perror("bind");
                exit(1);
        }

        memset(&pfd, 0, sizeof(pfd));
        pfd.fd = sock;
        pfd.events = POLLOUT | POLLERR;
        pfd.revents = 0;

        total_packets = NUM_PACKETS;
        create_payload(packet, &packet_len);

        while (total_packets > 0) {
                while (__v1_v2_tx_kernel_ready(ring->rd[frame_num].iov_base,
                                               ring->version) &&
                       total_packets > 0) {
                        ppd.raw = ring->rd[frame_num].iov_base;

                        switch (ring->version) {
                        case TPACKET_V1:
                                ppd.v1->tp_h.tp_snaplen = packet_len;
                                ppd.v1->tp_h.tp_len = packet_len;

                                memcpy((uint8_t *) ppd.raw + TPACKET_HDRLEN -
                                       sizeof(struct sockaddr_ll), packet,
                                       packet_len);
                                total_bytes += ppd.v1->tp_h.tp_snaplen;
                                break;

                        case TPACKET_V2:
                                ppd.v2->tp_h.tp_snaplen = packet_len;
                                ppd.v2->tp_h.tp_len = packet_len;

                                memcpy((uint8_t *) ppd.raw + TPACKET2_HDRLEN -
                                       sizeof(struct sockaddr_ll), packet,
                                       packet_len);
                                total_bytes += ppd.v2->tp_h.tp_snaplen;
                                break;
                        }

                        status_bar_update();
                        total_packets--;

                        __v1_v2_tx_user_ready(ppd.raw, ring->version);

                        frame_num = (frame_num + 1) % ring->rd_num;
                }

                poll(&pfd, 1, 1);
        }

        bug_on(total_packets != 0);

        ret = sendto(sock, NULL, 0, 0, NULL, 0);
        if (ret == -1) {
                perror("sendto");
                exit(1);
        }

        while ((ret = recvfrom(rcv_sock, packet, sizeof(packet),
                               0, NULL, NULL)) > 0 &&
               total_packets < NUM_PACKETS) {
                got += ret;
                test_payload(packet, ret);

                status_bar_update();
                total_packets++;
        }

        close(rcv_sock);

        if (total_packets != NUM_PACKETS) {
                fprintf(stderr, "walk_v%d_rx: received %u out of %u pkts\n",
                        ring->version, total_packets, NUM_PACKETS);
                exit(1);
        }

        fprintf(stderr, " %u pkts (%u bytes)", NUM_PACKETS, got);
}

static void walk_v1_v2(int sock, struct ring *ring)
{
        if (ring->type == PACKET_RX_RING)
                walk_v1_v2_rx(sock, ring);
        else
                walk_v1_v2_tx(sock, ring);
}

static uint64_t __v3_prev_block_seq_num = 0;

void __v3_test_block_seq_num(struct block_desc *pbd)
{
        if (__v3_prev_block_seq_num + 1 != pbd->h1.seq_num) {
                fprintf(stderr, "\nprev_block_seq_num:%"PRIu64", expected "
                        "seq:%"PRIu64" != actual seq:%"PRIu64"\n",
                        __v3_prev_block_seq_num, __v3_prev_block_seq_num + 1,
                        (uint64_t) pbd->h1.seq_num);
                exit(1);
        }

        __v3_prev_block_seq_num = pbd->h1.seq_num;
}

static void __v3_test_block_len(struct block_desc *pbd, uint32_t bytes, int block_num)
{
        if (pbd->h1.num_pkts && bytes != pbd->h1.blk_len) {
                fprintf(stderr, "\nblock:%u with %upackets, expected "
                        "len:%u != actual len:%u\n", block_num,
                        pbd->h1.num_pkts, bytes, pbd->h1.blk_len);
                exit(1);
        }
}

static void __v3_test_block_header(struct block_desc *pbd, const int block_num)
{
        if ((pbd->h1.block_status & TP_STATUS_USER) == 0) {
                fprintf(stderr, "\nblock %u: not in TP_STATUS_USER\n", block_num);
                exit(1);
        }

        __v3_test_block_seq_num(pbd);
}

static void __v3_walk_block(struct block_desc *pbd, const int block_num)
{
        int num_pkts = pbd->h1.num_pkts, i;
        unsigned long bytes = 0, bytes_with_padding = ALIGN_8(sizeof(*pbd));
        struct tpacket3_hdr *ppd;

        __v3_test_block_header(pbd, block_num);

        ppd = (struct tpacket3_hdr *) ((uint8_t *) pbd +
                                       pbd->h1.offset_to_first_pkt);

        for (i = 0; i < num_pkts; ++i) {
                bytes += ppd->tp_snaplen;

                if (ppd->tp_next_offset)
                        bytes_with_padding += ppd->tp_next_offset;
                else
                        bytes_with_padding += ALIGN_8(ppd->tp_snaplen + ppd->tp_mac);

                test_payload((uint8_t *) ppd + ppd->tp_mac, ppd->tp_snaplen);

                status_bar_update();
                total_packets++;

                ppd = (struct tpacket3_hdr *) ((uint8_t *) ppd + ppd->tp_next_offset);
                __sync_synchronize();
        }

        __v3_test_block_len(pbd, bytes_with_padding, block_num);
        total_bytes += bytes;
}

void __v3_flush_block(struct block_desc *pbd)
{
        pbd->h1.block_status = TP_STATUS_KERNEL;
        __sync_synchronize();
}

static void walk_v3_rx(int sock, struct ring *ring)
{
        unsigned int block_num = 0;
        struct pollfd pfd;
        struct block_desc *pbd;
        int udp_sock[2];

        bug_on(ring->type != PACKET_RX_RING);

        pair_udp_open(udp_sock, PORT_BASE);
        pair_udp_setfilter(sock);

        memset(&pfd, 0, sizeof(pfd));
        pfd.fd = sock;
        pfd.events = POLLIN | POLLERR;
        pfd.revents = 0;

        pair_udp_send(udp_sock, NUM_PACKETS);

        while (total_packets < NUM_PACKETS * 2) {
                pbd = (struct block_desc *) ring->rd[block_num].iov_base;

                while ((pbd->h1.block_status & TP_STATUS_USER) == 0)
                        poll(&pfd, 1, 1);

                __v3_walk_block(pbd, block_num);
                __v3_flush_block(pbd);

                block_num = (block_num + 1) % ring->rd_num;
        }

        pair_udp_close(udp_sock);

        if (total_packets != 2 * NUM_PACKETS) {
                fprintf(stderr, "walk_v3_rx: received %u out of %u pkts\n",
                        total_packets, NUM_PACKETS);
                exit(1);
        }

        fprintf(stderr, " %u pkts (%u bytes)", NUM_PACKETS, total_bytes >> 1);
}

static void walk_v3(int sock, struct ring *ring)
{
        if (ring->type == PACKET_RX_RING)
                walk_v3_rx(sock, ring);
        else
                bug_on(1);
}

static void __v1_v2_fill(struct ring *ring, unsigned int blocks)
{
        ring->req.tp_block_size = getpagesize() << 2;
        ring->req.tp_frame_size = TPACKET_ALIGNMENT << 7;
        ring->req.tp_block_nr = blocks;

        ring->req.tp_frame_nr = ring->req.tp_block_size /
                                ring->req.tp_frame_size *
                                ring->req.tp_block_nr;

        ring->mm_len = ring->req.tp_block_size * ring->req.tp_block_nr;
        ring->walk = walk_v1_v2;
        ring->rd_num = ring->req.tp_frame_nr;
        ring->flen = ring->req.tp_frame_size;
}

static void __v3_fill(struct ring *ring, unsigned int blocks)
{
        ring->req3.tp_retire_blk_tov = 64;
        ring->req3.tp_sizeof_priv = 0;
        ring->req3.tp_feature_req_word = TP_FT_REQ_FILL_RXHASH;

        ring->req3.tp_block_size = getpagesize() << 2;
        ring->req3.tp_frame_size = TPACKET_ALIGNMENT << 7;
        ring->req3.tp_block_nr = blocks;

        ring->req3.tp_frame_nr = ring->req3.tp_block_size /
                                 ring->req3.tp_frame_size *
                                 ring->req3.tp_block_nr;

        ring->mm_len = ring->req3.tp_block_size * ring->req3.tp_block_nr;
        ring->walk = walk_v3;
        ring->rd_num = ring->req3.tp_block_nr;
        ring->flen = ring->req3.tp_block_size;
}

static void setup_ring(int sock, struct ring *ring, int version, int type)
{
        int ret = 0;
        unsigned int blocks = 256;

        ring->type = type;
        ring->version = version;

        switch (version) {
        case TPACKET_V1:
        case TPACKET_V2:
                if (type == PACKET_TX_RING)
                        __v1_v2_set_packet_loss_discard(sock);
                __v1_v2_fill(ring, blocks);
                ret = setsockopt(sock, SOL_PACKET, type, &ring->req,
                                 sizeof(ring->req));
                break;

        case TPACKET_V3:
                __v3_fill(ring, blocks);
                ret = setsockopt(sock, SOL_PACKET, type, &ring->req3,
                                 sizeof(ring->req3));
                break;
        }

        if (ret == -1) {
                perror("setsockopt");
                exit(1);
        }

        ring->rd_len = ring->rd_num * sizeof(*ring->rd);
        ring->rd = malloc(ring->rd_len);
        if (ring->rd == NULL) {
                perror("malloc");
                exit(1);
        }

        total_packets = 0;
        total_bytes = 0;
}

static void mmap_ring(int sock, struct ring *ring)
{
        int i;

        ring->mm_space = mmap(0, ring->mm_len, PROT_READ | PROT_WRITE,
                              MAP_SHARED | MAP_LOCKED | MAP_POPULATE, sock, 0);
        if (ring->mm_space == MAP_FAILED) {
                perror("mmap");
                exit(1);
        }

        memset(ring->rd, 0, ring->rd_len);
        for (i = 0; i < ring->rd_num; ++i) {
                ring->rd[i].iov_base = ring->mm_space + (i * ring->flen);
                ring->rd[i].iov_len = ring->flen;
        }
}

static void bind_ring(int sock, struct ring *ring)
{
        int ret;

        ring->ll.sll_family = PF_PACKET;
        ring->ll.sll_protocol = htons(ETH_P_ALL);
        ring->ll.sll_ifindex = if_nametoindex("lo");
        ring->ll.sll_hatype = 0;
        ring->ll.sll_pkttype = 0;
        ring->ll.sll_halen = 0;

        ret = bind(sock, (struct sockaddr *) &ring->ll, sizeof(ring->ll));
        if (ret == -1) {
                perror("bind");
                exit(1);
        }
}

static void walk_ring(int sock, struct ring *ring)
{
        ring->walk(sock, ring);
}

static void unmap_ring(int sock, struct ring *ring)
{
        munmap(ring->mm_space, ring->mm_len);
        free(ring->rd);
}

static int test_kernel_bit_width(void)
{
        char in[512], *ptr;
        int num = 0, fd;
        ssize_t ret;

        fd = open("/proc/kallsyms", O_RDONLY);
        if (fd == -1) {
                perror("open");
                exit(1);
        }

        ret = read(fd, in, sizeof(in));
        if (ret <= 0) {
                perror("read");
                exit(1);
        }

        close(fd);

        ptr = in;
        while(!isspace(*ptr)) {
                num++;
                ptr++;
        }

        return num * 4;
}

static int test_user_bit_width(void)
{
        return __WORDSIZE;
}

static const char *tpacket_str[] = {
        [TPACKET_V1] = "TPACKET_V1",
        [TPACKET_V2] = "TPACKET_V2",
        [TPACKET_V3] = "TPACKET_V3",
};

static const char *type_str[] = {
        [PACKET_RX_RING] = "PACKET_RX_RING",
        [PACKET_TX_RING] = "PACKET_TX_RING",
};

static int test_tpacket(int version, int type)
{
        int sock;
        struct ring ring;

        fprintf(stderr, "test: %s with %s ", tpacket_str[version],
                type_str[type]);
        fflush(stderr);

        if (version == TPACKET_V1 &&
            test_kernel_bit_width() != test_user_bit_width()) {
                fprintf(stderr, "test: skip %s %s since user and kernel "
                        "space have different bit width\n",
                        tpacket_str[version], type_str[type]);
                return 0;
        }

        sock = pfsocket(version);
        memset(&ring, 0, sizeof(ring));
        setup_ring(sock, &ring, version, type);
        mmap_ring(sock, &ring);
        bind_ring(sock, &ring);
        walk_ring(sock, &ring);
        unmap_ring(sock, &ring);
        close(sock);

        fprintf(stderr, "\n");
        return 0;
}

int main(void)
{
        int ret = 0;

        ret |= test_tpacket(TPACKET_V1, PACKET_RX_RING);
        ret |= test_tpacket(TPACKET_V1, PACKET_TX_RING);

        ret |= test_tpacket(TPACKET_V2, PACKET_RX_RING);
        ret |= test_tpacket(TPACKET_V2, PACKET_TX_RING);

        ret |= test_tpacket(TPACKET_V3, PACKET_RX_RING);

        if (ret)
                return 1;

        printf("OK. All tests passed\n");
        return 0;
}