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icmp_direct_broadcast

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mykola2312 2024-12-20 16:33:57 +02:00
parent add77105af
commit 0b52ba64bb
1 changed files with 27 additions and 30 deletions
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57
main.c
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@ -220,6 +220,32 @@ ssize_t ip_send(linkinterface_t* link, const uint8_t* dstAddr,
return link_send(link, dstAddr, ETHERTYPE_IP, frame);
}
ssize_t icmp_direct_broadcast(linkinterface_t* link, const uint8_t* dstAddr, uint16_t seq) {
size_t hdrlen = sizeof(struct icmphdr);
const size_t payloadlen = 20;
frame_t* frame = frame_new(hdrlen + payloadlen);
struct icmphdr* icmp = (struct icmphdr*)frame->data;
icmp->type = ICMP_ECHO;
icmp->code = 0;
icmp->checksum = 0;
icmp->un.echo.id = htons(frame->id);
icmp->un.echo.sequence = htons(seq);
uint8_t* payload = (uint8_t*)frame->data + hdrlen;
for (unsigned i = 0; i < payloadlen; i++) {
payload[i] = rand() % 256;
}
icmp->checksum = checksum((const uint8_t*)frame->data, hdrlen + payloadlen);
const uint8_t ip_broadcast[4] = {255, 255, 255, 255};
size_t sent = ip_send(link, dstAddr, ip_broadcast, IPPROTO_ICMP, frame);
frame_free(frame);
return sent;
}
int main(int argc, char** argv) {
// ifname targetMAC
linkinterface_t* link = link_open(argv[1]);
@ -233,39 +259,10 @@ int main(int argc, char** argv) {
parse_mac(argv[2], target);
srand(time(NULL));
uint16_t id = (uint16_t)rand();
// ICMP request
size_t hdrlen = sizeof(struct icmphdr);
size_t payloadlen = 20;
frame_t* frame = frame_new(hdrlen + payloadlen);
struct icmphdr* icmp = (struct icmphdr*)frame->data;
icmp->type = ICMP_ECHO;
icmp->code = 0;
icmp->checksum = 0;
icmp->un.echo.id = htons(frame->id);
icmp->un.echo.sequence = 0;
// set payload
//struct timespec ts;
//clock_gettime(CLOCK_REALTIME, &ts);
uint8_t* payload = (uint8_t*)icmp + hdrlen;
for (uint8_t i = 0; i < payloadlen; i++) {
payload[i] = i;
}
//memcpy(payload, &ts, sizeof(struct timespec));
// calculate checksum
icmp->checksum = checksum((const uint8_t*)icmp, hdrlen + payloadlen);
// IPv4 local broadcast
uint8_t ip_broadcast[4] = {255, 255, 255, 255};
ssize_t sent = ip_send(link, target, ip_broadcast, IPPROTO_ICMP, frame);
ssize_t sent = icmp_direct_broadcast(link, target, 0);
printf("sent %ld\n", sent);
frame_free(frame);
link_free(link);
return 0;
}