Date: Mon, 28 Mar 2011 15:12:34 -0700 From: Maksim Yevmenkin <maksim.yevmenkin@gmail.com> To: Alexander Best <arundel@freebsd.org> Cc: freebsd-bluetooth@freebsd.org Subject: Re: l2ping(8) and -f switch Message-ID: <AANLkTi=SZLH72oqcjERP9u2hZHTNAtm5-LghSKUYqG%2BB@mail.gmail.com> In-Reply-To: <20110328215503.GA43845@freebsd.org> References: <20110328001258.GA70156@freebsd.org> <alpine.NEB.2.00.1103280751410.3331@galant.ukfsn.org> <20110328101804.GA39095@freebsd.org> <alpine.NEB.2.00.1103281452520.27263@galant.ukfsn.org> <AANLkTikLj7QumdtPcB=wGBdyxOyHBusCzUbrtXVC%2BYt1@mail.gmail.com> <20110328195952.GA26987@freebsd.org> <AANLkTin_%2B8dxE8Go1Bk1vdFg2-bUZ-fn3OHX1RTRmfKa@mail.gmail.com> <20110328203413.GB26987@freebsd.org> <20110328213746.GA42088@freebsd.org> <AANLkTi=QagnGN3cADEcXTW-j3G_pDu3KCUY09uN_KTzV@mail.gmail.com> <20110328215503.GA43845@freebsd.org>
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On Mon, Mar 28, 2011 at 2:55 PM, Alexander Best <arundel@freebsd.org> wrote: > On Mon Mar 28 11, Maksim Yevmenkin wrote: >> On Mon, Mar 28, 2011 at 2:37 PM, Alexander Best <arundel@freebsd.org> wrote: >> > On Mon Mar 28 11, Alexander Best wrote: >> >> On Mon Mar 28 11, Maksim Yevmenkin wrote: >> >> > On Mon, Mar 28, 2011 at 12:59 PM, Alexander Best <arundel@freebsd.org> wrote: >> >> > > On Mon Mar 28 11, Maksim Yevmenkin wrote: >> >> > >> On Mon, Mar 28, 2011 at 7:04 AM, Iain Hibbert <plunky@rya-online.net> wrote: >> >> > >> > On Mon, 28 Mar 2011, Alexander Best wrote: >> >> > >> > >> >> > >> >> On Mon Mar 28 11, Iain Hibbert wrote: >> >> > >> >> > On Mon, 28 Mar 2011, Alexander Best wrote: >> >> > >> >> > >> >> > >> >> > > thus i believe making the -f switch only accessable to super-users (in >> >> > >> >> > > accordance with ping(8)/ping6(8)) would increase security. >> >> > >> >> > >> >> > >> >> > what stops the user from recompiling l2ping without this restriction? >> >> > >> >> >> >> > >> >> nothing. but what stops him from recompiling ping(8) or ping6(8) without the >> >> > >> >> restriction? still it's there. >> >> > >> > >> >> > >> > AFAIK you need superuser privileges to even send ICMP_ECHO packets, thats >> >> > >> > why ping is traditionally a suid program and making a new binary won't >> >> > >> > help normal users.. I'm guessing that l2ping doesn't have the same >> >> > >> > restrictions? >> >> > >> >> >> > >> Guys, >> >> > >> >> >> > >> first of all thanks for the patch. >> >> > >> >> >> > >> i think one really needs to understand what "flood" really means in >> >> > >> l2ping(8). "flood" ping(8) basically floods the link with icmp echo >> >> > >> requests without waiting for remote system to reply. yes, this is >> >> > >> potentially dangerous and thus its reasonable to require super-user >> >> > >> privileges. "flood" l2ping(8) is NOT the same. all l2ping(8) does is >> >> > >> "flood" mode >> >> > >> >> >> > >> 1) sends l2cap echo request >> >> > >> 2) waits for l2cap echo response (or timeout) >> >> > >> 3) repeats >> >> > >> >> >> > >> in other words, there is no delay between each l2cap echo >> >> > >> request-response transaction. its not really "flood". i'm not sure if >> >> > >> it really worth to go all the way to restricting this. however, if >> >> > >> people think that it should be restricted, i will not object. >> >> > > >> >> > > how about removing the term "flood" from the l2ping(2) man page, if the -f >> >> > > semantics can't actually be called that way? >> >> > >> >> > that would be fine. l2ping(8) -h calls it >> >> > >> >> > -f No delay (sort of flood) >> >> > >> >> > and l2ping(8) man page calls it >> >> > >> >> > -f ``Flood'' ping, i.e., no delay between packets. >> >> > >> >> > it would be nice to make those consistent :) i'm not sure what the >> >> > best name would be though. >> >> >> >> another possibility would be to allow l2ping -i 0 and say that the -f flag is >> >> an alias for that. >> >> the existing code provides exactly this behavior. perhaps just a man >> page and usage() change? > > hmmm...no actually. l2ping -i 0 is not a valid parameter, since -i has to be > greater than 0. so it's not possible to simply say "-f is an alias for -i 0", > because that implies that -i 0 should work (which it doesn't). well, don't call it an "alias" then :) call it "effectively -i 0", "no delay" or something like that :) >> > the following patch will implement this behavior. >> >> if we are going to go this route then why not just get rid of the >> "flood" variable all together? just set wait to 0 (zero) if -f was >> specified. also, we should probably use strtol(3) instead of atoi(3). > > i've thought of that. however that would mean l2ping -f -i 3 would set the > delay to 3 seconds and usually an -f switch implies "force". so i think the > current behavior of -f having a higher priority than any -i X option should be > kept. i think that this is not worthy of long discussion :) i agree that word 'flood' is not appropriate and/or confusing. all the patches provided were fine, imo. please make a decision and commit the best (in your opinion) fix. thank you max
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