1 /* dumpleases.c - Dump the leases granted by udhcpd. 2 * 3 * Copyright 2013 Sandeep Sharma <sandeep.jack2756 (at) gmail.com> 4 * Copyright 2013 Kyungwan Han <asura321 (at) gmail.com> 5 * 6 7 USE_DUMPLEASES(NEWTOY(dumpleases, ">0arf:[!ar]", TOYFLAG_USR|TOYFLAG_BIN)) 8 9 config DUMPLEASES 10 bool "dumpleases" 11 default n 12 help 13 usage: dumpleases [-r|-a] [-f LEASEFILE] 14 15 Display DHCP leases granted by udhcpd 16 -f FILE, Lease file 17 -r Show remaining time 18 -a Show expiration time 19 */ 20 21 #define FOR_dumpleases 22 #include "toys.h" 23 24 GLOBALS( 25 char *file; 26 ) 27 28 //lease structure 29 struct lease { 30 uint32_t expires; 31 uint32_t lease_nip; 32 uint8_t lease_mac[6]; 33 char hostname[20]; 34 uint8_t pad[2]; //Padding 35 }; 36 37 void dumpleases_main(void) 38 { 39 struct in_addr addr; 40 struct lease lease_struct; 41 int64_t written_time , current_time, exp; 42 int i, fd; 43 44 if(!(toys.optflags & FLAG_f)) TT.file = "/var/lib/misc/dhcpd.leases"; //DEF_LEASE_FILE 45 fd = xopenro(TT.file); 46 xprintf("Mac Address IP Address Host Name Expires %s\n", (toys.optflags & FLAG_a) ? "at" : "in"); 47 xread(fd, &written_time, sizeof(written_time)); 48 current_time = time(NULL); 49 written_time = SWAP_BE64(written_time); 50 if(current_time < written_time) written_time = current_time; 51 52 while(sizeof(lease_struct) == 53 (readall(fd, &lease_struct, sizeof(lease_struct)))) { 54 for (i = 0; i < 6; i++) printf(":%02x"+ !i, lease_struct.lease_mac[i]); 55 56 addr.s_addr = lease_struct.lease_nip; 57 lease_struct.hostname[19] = '\0'; 58 xprintf(" %-16s%-20s", inet_ntoa(addr), lease_struct.hostname ); 59 exp = ntohl(lease_struct.expires) + written_time; 60 if (exp <= current_time) { 61 xputs("expired"); 62 continue; 63 } 64 if (!(toys.optflags & FLAG_a)) { 65 unsigned dt, hr, m; 66 unsigned expires = exp - current_time; 67 dt = expires / (24*60*60); expires %= (24*60*60); 68 hr = expires / (60*60); expires %= (60*60); 69 m = expires / 60; expires %= 60; 70 if (dt) xprintf("%u days ", dt); 71 xprintf("%02u:%02u:%02u\n", hr, m, (unsigned)expires); 72 } else { 73 fputs(ctime((const time_t*)&exp), stdout); 74 } 75 } 76 xclose(fd); 77 } 78
