From: guy <guy>
Date: Thu, 9 Feb 2006 22:26:12 +0000 (+0000)
Subject: Clean up some comments, and give more details so people understand what
X-Git-Tag: libpcap-1.1.0~554
X-Git-Url: https://git.tcpdump.org/libpcap/commitdiff_plain/3adb2d4f0d2e86c37fada6417e63b28d3a48a511?ds=sidebyside

Clean up some comments, and give more details so people understand what
they do, and don't, have to do about 32-bit vs. 64-bit platforms in
libpcap.
---

diff --git a/pcap-int.h b/pcap-int.h
index 49fa3ef5..7e4c1410 100644
--- a/pcap-int.h
+++ b/pcap-int.h
@@ -30,7 +30,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * @(#) $Header: /tcpdump/master/libpcap/pcap-int.h,v 1.76 2005-11-24 19:27:42 guy Exp $ (LBL)
+ * @(#) $Header: /tcpdump/master/libpcap/pcap-int.h,v 1.77 2006-02-09 22:26:12 guy Exp $ (LBL)
  */
 
 #ifndef pcap_int_h
@@ -189,9 +189,13 @@ struct pcap {
 };
 
 /*
- * This is a timeval as stored in disk in a dumpfile.
+ * This is a timeval as stored in a savefile.
  * It has to use the same types everywhere, independent of the actual
- * `struct timeval'
+ * `struct timeval'; `struct timeval' has 32-bit tv_sec values on some
+ * platforms and 64-bit tv_sec values on other platforms, and writing
+ * out native `struct timeval' values would mean files could only be
+ * read on systems with the same tv_sec size as the system on which
+ * the file was written.
  */
 
 struct pcap_timeval {
@@ -200,7 +204,7 @@ struct pcap_timeval {
 };
 
 /*
- * How a `pcap_pkthdr' is actually stored in the dumpfile.
+ * This is a `pcap_pkthdr' as actually stored in a savefile.
  *
  * Do not change the format of this structure, in any way (this includes
  * changes that only affect the length of fields in this structure),
@@ -232,7 +236,7 @@ struct pcap_sf_pkthdr {
 };
 
 /*
- * How a `pcap_pkthdr' is actually stored in dumpfiles written
+ * How a `pcap_pkthdr' is actually stored in savefiles written
  * by some patched versions of libpcap (e.g. the ones in Red
  * Hat Linux 6.1 and 6.2).
  *
diff --git a/pcap.h b/pcap.h
index 9a5aafa4..59589edb 100644
--- a/pcap.h
+++ b/pcap.h
@@ -31,7 +31,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * @(#) $Header: /tcpdump/master/libpcap/pcap.h,v 1.57 2005-07-07 01:57:03 guy Exp $ (LBL)
+ * @(#) $Header: /tcpdump/master/libpcap/pcap.h,v 1.58 2006-02-09 22:26:12 guy Exp $ (LBL)
  */
 
 #ifndef lib_pcap_h
@@ -127,9 +127,16 @@ typedef enum {
 } pcap_direction_t;
 
 /*
- * Each packet in the dump file is prepended with this generic header.
- * This gets around the problem of different headers for different
- * packet interfaces.
+ * Generic per-packet information, as supplied by libpcap.
+ *
+ * The time stamp can and should be a "struct timeval", regardless of
+ * whether your system supports 32-bit tv_sec in "struct timeval",
+ * 64-bit tv_sec in "struct timeval", or both if it supports both 32-bit
+ * and 64-bit applications.  The on-disk format of savefiles uses 32-bit
+ * tv_sec (and tv_usec); this structure is irrelevant to that.  32-bit
+ * and 64-bit versions of libpcap, even if they're on the same platform,
+ * should supply the appropriate version of "struct timeval", even if
+ * that's not what the underlying packet capture mechanism supplies.
  */
 struct pcap_pkthdr {
 	struct timeval ts;	/* time stamp */