#include <poll.h>
#include <sys/mman.h>
#include <arpa/inet.h>
+#include <fcntl.h>
+#include <errno.h>
#ifndef SO_BUSY_POLL
#define SO_BUSY_POLL 46
enum { WRITE, OUT_MMAP } out_method = WRITE;
bool quiet = false;
int busy_poll_us = 0;
+bool nonblocking = false;
enum in2out {
STORE_ONLY,
SEND,
+ NOP,
};
enum in2out in_read(struct in_ctx *ctx, struct can_frame *cf)
{
int ret = read(ctx->s, cf, sizeof(*cf));
+ if (nonblocking && ret == -1 && errno == EAGAIN)
+ return NOP;
if (ret != sizeof(*cf)) {
perror("read");
exit(1);
s = CHECK(socket(PF_CAN, SOCK_RAW, CAN_RAW));
+ if (nonblocking) {
+ int flags = CHECK(fcntl(s, F_GETFL, 0));
+ CHECK(fcntl(s, F_SETFL, flags | O_NONBLOCK));
+ }
+
if (busy_poll_us) {
CHECK(setsockopt(s, SOL_SOCKET, SO_BUSY_POLL,
&busy_poll_us, sizeof(busy_poll_us)));
int out_write(struct out_ctx *ctx, struct can_frame *cf)
{
+ if (ctx->from_in == NOP)
+ return 0;
+
int ret = write(ctx->s, cf, sizeof(*cf));
if (ret != sizeof(*cf)) {
perror("write");
volatile struct tpacket2_hdr *hdr = ctx->ptr + ctx->current*FRAME_SIZE;
int ret = -1;
+ if (ctx->from_in == NOP)
+ return 0;
+
+
while (hdr->tp_status != TP_STATUS_AVAILABLE) {
struct pollfd pfd = {.fd = ctx->s, .revents = 0,
.events = POLLIN|POLLRDNORM|POLLERR };
while (1) {
oc.from_in = in(&ic, &cf);
+ switch (oc.from_in) {
+ case SEND: stats.send++; break;
+ case STORE_ONLY: stats.store++; break;
+ case NOP: break;
+ }
out(&oc, &cf);
}
}
{
int opt;
- while ((opt = getopt(argc, argv, "b:qr:t:")) != -1) {
+ while ((opt = getopt(argc, argv, "b:nqr:t:")) != -1) {
switch (opt) {
case 'b':
busy_poll_us = atoi(optarg);
break;
+ case 'n':
+ nonblocking = true;
+ break;
case 'q':
quiet = true;
break;