diff options
Diffstat (limited to 'mndp.c')
| -rw-r--r-- | mndp.c | 11 |
1 files changed, 11 insertions, 0 deletions
@@ -31,13 +31,16 @@ int main(int argc, char **argv) { unsigned char name[100]; unsigned char mac[ETH_ALEN]; + /* Open a UDP socket handle */ sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); + /* Set initialize address/port */ memset((char *) &si_me, 0, sizeof(si_me)); si_me.sin_family = AF_INET; si_me.sin_port = htons(5678); si_me.sin_addr.s_addr = htonl(INADDR_ANY); + /* Bind to specified address/port */ if (bind(sock, (struct sockaddr *)&si_me, sizeof(si_me))==-1) { fprintf(stderr, "Error binding to %s:5678\n", inet_ntoa(si_me.sin_addr)); return 1; @@ -47,25 +50,33 @@ int main(int argc, char **argv) { fprintf(stderr, "Searching for MikroTik routers... Abort with CTRL+C.\n"); while(1) { + /* Wait for a UDP packet */ result = recvfrom(sock, buff, 1500, 0, 0, 0); if (result < 0) { fprintf(stderr, "Error occured. aborting\n"); exit(1); } + /* Fetch length of Identifier string */ memcpy(&nameLen, buff+16,2); nameLen = (nameLen >> 8) | ((nameLen&0xff)<<8); /* Max name length = 99 */ nameLen = nameLen < 100 ? nameLen : 99; + /* Read Identifier string */ memcpy(&name, buff+18, nameLen); + + /* Append zero */ name[nameLen] = 0; + /* Read source MAC address */ memcpy(&mac, buff+8, ETH_ALEN); + /* Print it */ printf("%17s %s\n", ether_ntoa((struct ether_addr *)mac), name); } + /* We'll never get here.. */ return 0; } |