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dumpleases.c 3.5 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  4. */
  5. //applet:IF_DUMPLEASES(APPLET_NOEXEC(dumpleases, dumpleases, BB_DIR_USR_BIN, BB_SUID_DROP, dumpleases))
  6. //kbuild:lib-$(CONFIG_DUMPLEASES) += dumpleases.o
  7. //usage:#define dumpleases_trivial_usage
  8. //usage: "[-r|-a] [-d] [-f LEASEFILE]"
  9. //usage:#define dumpleases_full_usage "\n\n"
  10. //usage: "Display DHCP leases granted by udhcpd\n"
  11. //usage: IF_LONG_OPTS(
  12. //usage: "\n -f,--file FILE Lease file"
  13. //usage: "\n -r,--remaining Show remaining time"
  14. //usage: "\n -a,--absolute Show expiration time"
  15. //usage: "\n -d,--decimal Show time in seconds"
  16. //usage: )
  17. //usage: IF_NOT_LONG_OPTS(
  18. //usage: "\n -f FILE Lease file"
  19. //usage: "\n -r Show remaining time"
  20. //usage: "\n -a Show expiration time"
  21. //usage: "\n -d Show time in seconds"
  22. //usage: )
  23. #include "common.h"
  24. #include "dhcpd.h"
  25. #include "unicode.h"
  26. int dumpleases_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  27. int dumpleases_main(int argc UNUSED_PARAM, char **argv)
  28. {
  29. int fd;
  30. int i;
  31. unsigned opt;
  32. int64_t written_at, curr;
  33. const char *file = LEASES_FILE;
  34. struct dyn_lease lease;
  35. enum {
  36. OPT_a = 0x1, // -a
  37. OPT_r = 0x2, // -r
  38. OPT_f = 0x4, // -f
  39. OPT_d = 0x8, // -d
  40. };
  41. #if ENABLE_LONG_OPTS
  42. static const char dumpleases_longopts[] ALIGN1 =
  43. "absolute\0" No_argument "a"
  44. "remaining\0" No_argument "r"
  45. "file\0" Required_argument "f"
  46. "decimal\0" No_argument "d"
  47. ;
  48. #endif
  49. init_unicode();
  50. opt = getopt32long(argv, "^"
  51. "arf:d"
  52. "\0" "=0:a--r:r--a",
  53. dumpleases_longopts,
  54. &file
  55. );
  56. fd = xopen(file, O_RDONLY);
  57. /* "123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 */
  58. /* "00:00:00:00:00:00 255.255.255.255 ABCDEFGHIJKLMNOPQRS Wed Jun 30 21:49:08 1993" */
  59. printf("Mac %-14s" "IP %-13s" "Host %-15s" "Expires %s\n",
  60. "Address", "Address", "Name",
  61. (opt & OPT_a) ? "at" : "in"
  62. );
  63. xread(fd, &written_at, sizeof(written_at));
  64. written_at = SWAP_BE64(written_at);
  65. curr = time(NULL);
  66. if (curr < written_at)
  67. written_at = curr; /* lease file from future! :) */
  68. while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
  69. struct in_addr addr;
  70. int64_t expires_abs;
  71. const char *fmt = ":%02x" + 1;
  72. for (i = 0; i < 6; i++) {
  73. printf(fmt, lease.lease_mac[i]);
  74. fmt = ":%02x";
  75. }
  76. addr.s_addr = lease.lease_nip;
  77. #if ENABLE_UNICODE_SUPPORT
  78. {
  79. char *uni_name = unicode_conv_to_printable_fixedwidth(/*NULL,*/ lease.hostname, 19);
  80. printf(" %-16s%s ", inet_ntoa(addr), uni_name);
  81. free(uni_name);
  82. }
  83. #else
  84. /* actually, 15+1 and 19+1, +1 is a space between columns */
  85. /* lease.hostname is char[20] and is always NUL terminated */
  86. printf(" %-16s%-20s", inet_ntoa(addr), lease.hostname);
  87. #endif
  88. expires_abs = ntohl(lease.expires) + written_at;
  89. if (expires_abs <= curr) {
  90. puts("expired");
  91. continue;
  92. }
  93. if (opt & OPT_d) {
  94. /* -d: decimal time */
  95. if (!(opt & OPT_a))
  96. expires_abs -= curr;
  97. printf("%llu\n", (unsigned long long) expires_abs);
  98. continue;
  99. }
  100. if (!(opt & OPT_a)) { /* no -a */
  101. unsigned d, h, m;
  102. unsigned expires = expires_abs - curr;
  103. d = expires / (24*60*60); expires %= (24*60*60);
  104. h = expires / (60*60); expires %= (60*60);
  105. m = expires / 60; expires %= 60;
  106. if (d)
  107. printf("%u days ", d);
  108. printf("%02u:%02u:%02u\n", h, m, (unsigned)expires);
  109. } else { /* -a */
  110. time_t t = expires_abs;
  111. fputs(ctime(&t), stdout);
  112. }
  113. }
  114. /* close(fd); */
  115. return 0;
  116. }