Date: Sat, 21 May 2005 09:27:38 -0700 (PDT) From: Daniel Valencia <fetrovsky@yahoo.com> To: freebsd-net@freebsd.org Subject: Re: sending MAC packets --- again, and again Message-ID: <20050521162738.29477.qmail@web53905.mail.yahoo.com> In-Reply-To: 6667
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Hello and thanks for your prompt answer... I followed your (Jon Simola's) advice, so i defined BUFSIZ as 2000, although my tutorial said it was defined somewhere in the pcap headers, and added a pcap_loop instead of the pcap_next. I also modified the program to only show packets that are sent from a broadcast address and to a broadcast address (which is how i'm sending my packets). I can see almost all the packets I send. The issue is a little interesting, because I'd expect in a network with almost no trafic for my packets to show up immediately. Actually, at startup my sniffer stalls for a good minute and half, during which period some of the packets I send will show up and some will not, and after all the bunch is printed, it stalls again, while I keep putting messages in the wire from the other machine. After some more 60 seconds have passed, i see all of the messages appear all at once. Is this normal pcap behaviour, or is it some FreeBSD-specific behaviour, or is it just me? Thank you again - Daniel --- Jon Simola <jsimola@gmail.com> wrote: > On 5/20/05, Daniel Valencia <fetrovsky@yahoo.com> > wrote: > > > my sniffer just stalls and eventually will report > a totally unrelated message. > ... > > handle = pcap_open_live( "xl0", BUFSIZ, 1, > 0, errbuf ); > > Uh, you're asking it to wait forever to see a > packet. I don't see a > #define in there for BUFSIZ, so you might be asking > it to catch zero > bytes. And what is the "totally unrelsated message"? > > I'd try using pcap_loop() or friends so you can > catch and examine more > than a single packet. > > And don't forget to call pcap_close() at the end, > I'm not sure how > polite pcap is about leaving dangling bpf devices. > > -- > Jon Simola > Systems Administrator > ABC Communications > Yahoo! Mail Stay connected, organized, and protected. Take the tour: http://tour.mail.yahoo.com/mailtour.html
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