Manpages - pcap_list_datalinks.3pcap

pcap_list_datalinks, pcap_free_datalinks - get a list of link-layer header types supported by a capture device, and free that list

  #include <pcap/pcap.h>
  int pcap_list_datalinks(pcap_t *p, int **dlt_buf);
  void pcap_free_datalinks(int *dlt_list);

*pcap_list_datalinks*() is used to get a list of the supported link-layer header types of the interface associated with the pcap descriptor. *pcap_list_datalinks*() allocates an array to hold the list and sets *dlt_buf to point to that array.

The caller is responsible for freeing the array with *pcap_free_datalinks*(), which frees the list of link-layer header types pointed to by dlt_list.

It must not be called on a pcap descriptor created by *pcap_create*(3PCAP) that has not yet been activated by *pcap_activate*(3PCAP).

pcap_list_datalinks*() returns the number of link-layer header types in the array on success, *PCAP_ERROR_NOT_ACTIVATED if called on a capture handle that has been created but not activated, and PCAP_ERROR on other errors. If PCAP_ERROR is returned, *pcap_geterr*(3PCAP) or *pcap_perror*(3PCAP) may be called with p as an argument to fetch or display the error text.

*pcap*(3PCAP), *pcap_datalink_val_to_name*(3PCAP), *pcap-linktype*(7)