diff options
Diffstat (limited to 'wiretap/wtap.h')
| -rw-r--r-- | wiretap/wtap.h | 42 |
1 files changed, 35 insertions, 7 deletions
diff --git a/wiretap/wtap.h b/wiretap/wtap.h index 10c498c55f..1f0a23baac 100644 --- a/wiretap/wtap.h +++ b/wiretap/wtap.h @@ -821,18 +821,46 @@ struct wtap_nstime { }; struct wtap_pkthdr { + guint32 presence_flags; /* what stuff do we have? */ struct wtap_nstime ts; - guint32 caplen; /* data length in the file */ - guint32 len; /* data length on the wire */ - int pkt_encap; + guint32 caplen; /* data length in the file */ + guint32 len; /* data length on the wire */ + int pkt_encap; /* pcapng variables */ - guint32 interface_id; /* identifier of the interface. */ + guint32 interface_id; /* identifier of the interface. */ /* options */ - gchar *opt_comment; /* NULL if not available */ - guint64 drop_count; /* number of packets lost (by the interface and the operating system) between this packet and the preceding one. */ - guint32 pack_flags; /* XXX - 0 for now (any value for "we don't have it"?) */ + gchar *opt_comment; /* NULL if not available */ + guint64 drop_count; /* number of packets lost (by the interface and the operating system) between this packet and the preceding one. */ + guint32 pack_flags; /* XXX - 0 for now (any value for "we don't have it"?) */ }; +/* + * Bits in presence_flags, indicating which of the fields we have. + * + * For the time stamp, we may need some more flags to indicate + * whether the time stamp is an absolute date-and-time stamp, an + * absolute time-only stamp (which can make relative time + * calculations tricky, as you could in theory have two time + * stamps separated by an unknown number of days), or a time stamp + * relative to some unspecified time in the past (see mpeg.c). + * + * There is no presence flag for len - there has to be *some* length + * value for the packet. (The "captured length" can be missing if + * the file format doesn't report a captured length distinct from + * the on-the-network length because the application(s) producing those + * files don't support slicing packets.) + * + * There could be a presence flag for the packet encapsulation - if it's + * absent, use the file encapsulation - but it's not clear that's useful; + * we currently do that in the module for the file format. + */ +#define WTAP_HAS_TS 0x00000001 /* time stamp */ +#define WTAP_HAS_CAP_LEN 0x00000002 /* captured length separate from on-the-network length */ +#define WTAP_HAS_INTERFACE_ID 0x00000004 /* interface ID */ +#define WTAP_HAS_COMMENTS 0x00000008 /* comments */ +#define WTAP_HAS_DROP_COUNT 0x00000010 /* drop count */ +#define WTAP_HAS_PACK_FLAGS 0x00000020 /* packet flags */ + /** * Holds the option strings from pcapng:s Section Header block(SHB). */ |