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AF_XDP-interaction: Add --pktinfo option that print info on pkt

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To verify the contents of the incomming packets add a
function print_pkt_info() that decode part of the packet
headers and print IP-header src+dst (both IPv4 and IPv6).

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
This commit is contained in:
Jesper Dangaard Brouer
2021-10-29 14:53:33 +02:00
parent 54d51b06b4
commit 1bc02a7470
3 changed files with 40 additions and 0 deletions
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35
AF_XDP-interaction/af_xdp_user.c
View File

@@ -22,6 +22,7 @@
#include <net/if.h>
#include <linux/if_link.h>
#include <linux/if_ether.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
@@ -112,6 +113,9 @@ static const struct option_wrapper long_options[] = {
{{"quiet", no_argument, NULL, 'q' },
"Quiet mode (no output)"},
{{"pktinfo", no_argument, NULL, 'P' },
"Print packet info output mode (debug)"},
{{"filename", required_argument, NULL, 1 },
"Load program from <file>", "<file>"},
@@ -290,11 +294,42 @@ static inline void csum_replace2(__sum16 *sum, __be16 old, __be16 new)
*sum = ~csum16_add(csum16_sub(~(*sum), old), new);
}
/* As debug tool print some info about packet */
static void print_pkt_info(uint8_t *pkt, uint32_t len)
{
struct ethhdr *eth = (struct ethhdr *) pkt;
__u16 proto = ntohs(eth->h_proto);
char *fmt = "DEBUG-pkt len=%04d Eth-proto:0x%X %s "
"src:%s -> dst:%s\n";
char src_str[128] = { 0 };
char dst_str[128] = { 0 };
if (proto == ETH_P_IP) {
struct iphdr *ipv4 = (struct iphdr *) (eth + 1);
inet_ntop(AF_INET, &ipv4->saddr, src_str, sizeof(src_str));
inet_ntop(AF_INET, &ipv4->daddr, dst_str, sizeof(dst_str));
printf(fmt, len, proto, "IPv4", src_str, dst_str);
} else if (proto == ETH_P_ARP) {
printf(fmt, len, proto, "ARP", "", "");
} else if (proto == ETH_P_IPV6) {
struct ipv6hdr *ipv6 = (struct ipv6hdr *) (eth + 1);
inet_ntop(AF_INET6, &ipv6->saddr, src_str, sizeof(src_str));
inet_ntop(AF_INET6, &ipv6->daddr, dst_str, sizeof(dst_str));
printf(fmt, len, proto, "IPv6", src_str, dst_str);
} else {
printf(fmt, len, proto, "Unknown", "", "");
}
}
static bool process_packet(struct xsk_socket_info *xsk,
uint64_t addr, uint32_t len)
{
uint8_t *pkt = xsk_umem__get_data(xsk->umem->buffer, addr);
if (debug_pkt)
print_pkt_info(pkt, len);
/* Lesson#3: Write an IPv6 ICMP ECHO parser to send responses
*
* Some assumptions to make it easier:

1
AF_XDP-interaction/common_defines.h
View File

@@ -27,6 +27,7 @@ struct config {
/* Defined in common_params.o */
extern int verbose;
extern int debug_pkt;
/* Exit return codes */
#define EXIT_OK 0 /* == EXIT_SUCCESS (stdlib.h) man exit(3) */

4
AF_XDP-interaction/common_params.c
View File

@@ -13,6 +13,7 @@
#include "common_params.h"
int verbose = 1;
int debug_pkt = 0;
#define BUFSIZE 30
@@ -157,6 +158,9 @@ void parse_cmdline_args(int argc, char **argv,
case 'q':
verbose = false;
break;
case 'P':
debug_pkt = true;
break;
case 'Q':
cfg->xsk_if_queue = atoi(optarg);
break;