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// 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 <arpa/inet.h>
#include <assert.h>
#include <error.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/filter.h>
#include <linux/if_packet.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <poll.h>
#include <pthread.h>
#include <sched.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
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 == MAP_FAILED)
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;
}
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