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Created March 17, 2023 10:06
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AF_PACKET buffer increase test program
/*
Provided under the MIT No Attribution License
https://opensource.org/license/mit-0/
Copyright 2023 Lars Ekman <[email protected]>
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation files
(the “Software”), to deal in the Software without restriction,
including without limitation the rights to use, copy, modify, merge,
publish, distribute, sublicense, and/or sell copies of the Software,
and to permit persons to whom the Software is furnished to do so.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
/*
A simple example of an AF_PACKET (raw) socket for Linux. The program
counts packets and supports a configurable receive buffer size
Some code taken from:
http://www.microhowto.info/howto/capture_ethernet_frames_using_an_af_packet_socket_in_c.html
Syntax;
af_packet [interface] [recv-buffer-size]
Also see;
/proc/sys/net/core/rmem_default
/proc/sys/net/core/rmem_max
Build;
gcc -Wall -Werror -o af_packet af_packet.c
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <net/ethernet.h>
#include <linux/if_packet.h>
#include <sys/ioctl.h>
#include <net/if.h>
int main(int argc, char* argv[])
{
int fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if (fd < 0) {
perror("socket");
return 1;
}
if (argc > 1) {
struct ifreq ifr;
strcpy(ifr.ifr_name, argv[1]);
if (ioctl(fd,SIOCGIFINDEX, &ifr) == -1) {
perror("ioctl");
return 1;
}
struct sockaddr_ll addr = {0};
addr.sll_family = AF_PACKET;
addr.sll_ifindex = ifr.ifr_ifindex;
addr.sll_protocol = htons(ETH_P_ALL);
if (bind(fd, (struct sockaddr*)&addr, sizeof(addr)) == -1) {
perror("bind");
return 1;
}
}
if (argc > 2) {
int n = 0;
socklen_t socklen = sizeof(n);
if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &n, &socklen) != 0) {
perror("getsockopt");
return 1;
}
int newsize = atoi(argv[2]);
printf("SO_RCVBUF: current = %d, new = %d\n", n, newsize);
if (setsockopt(fd, SOL_SOCKET, SO_RCVBUFFORCE, &newsize, socklen) != 0) {
perror("getsockopt");
return 1;
}
if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &n, &socklen) != 0) {
perror("getsockopt");
return 1;
}
printf("SO_RCVBUF: after update = %d\n", n);
}
char buffer[1024*64];
struct sockaddr_ll src_addr;
socklen_t src_addr_len = sizeof(src_addr);
unsigned packets = 0;
size_t count = recvfrom(
fd, buffer, sizeof(buffer), 0, (struct sockaddr*)&src_addr, &src_addr_len);
while (count > 0) {
packets++;
if (packets % 100 == 0)
printf("Packets %u\r", packets);
fflush(stdout);
count = recvfrom(
fd, buffer, sizeof(buffer), 0, (struct sockaddr*)&src_addr, &src_addr_len);
}
return 0;
}
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