udpcksum.lc 2.1 KB

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  1. /* include sig_alrm */
  2. #include "udpcksum.h"## 1 ##src/udpcksum/udpcksum.c##
  3. #include <setjmp.h>## 2 ##src/udpcksum/udpcksum.c##
  4. static sigjmp_buf jmpbuf;## 3 ##src/udpcksum/udpcksum.c##
  5. static int canjump;## 4 ##src/udpcksum/udpcksum.c##
  6. void## 5 ##src/udpcksum/udpcksum.c##
  7. sig_alrm(int signo)## 6 ##src/udpcksum/udpcksum.c##
  8. {## 7 ##src/udpcksum/udpcksum.c##
  9. if (canjump == 0)## 8 ##src/udpcksum/udpcksum.c##
  10. return;## 9 ##src/udpcksum/udpcksum.c##
  11. siglongjmp(jmpbuf, 1);## 10 ##src/udpcksum/udpcksum.c##
  12. }## 11 ##src/udpcksum/udpcksum.c##
  13. /* end sig_alrm */
  14. /* include test_udp */
  15. void## 12 ##src/udpcksum/udpcksum.c##
  16. test_udp(void)## 13 ##src/udpcksum/udpcksum.c##
  17. {## 14 ##src/udpcksum/udpcksum.c##
  18. volatile int nsent = 0, timeout = 3;## 15 ##src/udpcksum/udpcksum.c##
  19. struct udpiphdr *ui;## 16 ##src/udpcksum/udpcksum.c##
  20. Signal(SIGALRM, sig_alrm);## 17 ##src/udpcksum/udpcksum.c##
  21. if (sigsetjmp(jmpbuf, 1)) {## 18 ##src/udpcksum/udpcksum.c##
  22. if (nsent >= 3)## 19 ##src/udpcksum/udpcksum.c##
  23. err_quit("no response");## 20 ##src/udpcksum/udpcksum.c##
  24. printf("timeout\n");## 21 ##src/udpcksum/udpcksum.c##
  25. timeout *= 2; /* exponential backoff: 3, 6, 12 */## 22 ##src/udpcksum/udpcksum.c##
  26. }## 23 ##src/udpcksum/udpcksum.c##
  27. canjump = 1; /* siglongjmp is now OK */## 24 ##src/udpcksum/udpcksum.c##
  28. send_dns_query();## 25 ##src/udpcksum/udpcksum.c##
  29. nsent++;## 26 ##src/udpcksum/udpcksum.c##
  30. alarm(timeout);## 27 ##src/udpcksum/udpcksum.c##
  31. ui = udp_read();## 28 ##src/udpcksum/udpcksum.c##
  32. canjump = 0;## 29 ##src/udpcksum/udpcksum.c##
  33. alarm(0);## 30 ##src/udpcksum/udpcksum.c##
  34. if (ui->ui_sum == 0)## 31 ##src/udpcksum/udpcksum.c##
  35. printf("UDP checksums off\n");## 32 ##src/udpcksum/udpcksum.c##
  36. else## 33 ##src/udpcksum/udpcksum.c##
  37. printf("UDP checksums on\n");## 34 ##src/udpcksum/udpcksum.c##
  38. if (verbose)## 35 ##src/udpcksum/udpcksum.c##
  39. printf("received UDP checksum = %x\n", ntohs(ui->ui_sum));## 36 ##src/udpcksum/udpcksum.c##
  40. }## 37 ##src/udpcksum/udpcksum.c##
  41. /* end test_udp */