Being a small-scale ISP
in [UK Linux]
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From: Ian on 22 Dec 2008 13:46 Dear All, For a research project I need to set up a PC which can a) Accept incoming phone calls through a modem, set up a PPP connection, and bridge across to a standard broadband connection through a router (ie being an ISP for one other computer) and b) run a web proxy which can convert all JPGs into GIFs and modify the pages it's passing on appropriately - not unlike T-Mobile does when it replaces images with lo-res versions. It would also be useful if it could block all flash content and replace it with an icon saying "Flash content blocked". Can anyone point me in the direction of Linux stuff to do this? I'm afraid the purpose has to be confidential for now, but if anyone who could help really feels a need to know, email me and I'll tell you what I can. Ian
From: Will Kemp on 22 Dec 2008 15:11 Ian wrote: > Dear All, > > For a research project I need to set up a PC which can > > a) Accept incoming phone calls through a modem, set up a PPP > connection, and bridge across to a standard broadband connection > through a router (ie being an ISP for one other computer) and > > b) run a web proxy which can convert all JPGs into GIFs and modify the > pages it's passing on appropriately - not unlike T-Mobile does when it > replaces images with lo-res versions. It would also be useful if it > could block all flash content and replace it with an icon saying > "Flash content blocked". > > Can anyone point me in the direction of Linux stuff to do this? I'm > afraid the purpose has to be confidential for now, but if anyone who > could help really feels a need to know, email me and I'll tell you > what I can. Well, considering how many times i've set up this sort of thing, i'm surprised at how much of a struggle it is to remember how to do it. Mercifully it's been quite a few years since i had to set up a dial-in ppp service! The connection basics require a getty and pppd. A "getty" initialises the modem and monitors the serial port(s) and sets up a connection when someone dials in. Basically it just needs to start pppd when it gets a connection. pppd will set up the IP connection (using IPCP) and do the authentication (using PAP, probably, or maybe CHAP). We used to use mgetty in the old days, but i notice agetty is shipped with Fedora (but not mgetty), so that's probably the thing to use now. You need to read the agetty and pppd man pages to find out what options to use etc. You may also find a HOWTO or two that help. Replacing jpegs with gifs is a bit more challenging, but you may find a way to do it with transparent proxying (using iptables), using squid as the proxy and passing the images through jpegtopnm and then pipe the output through ppmtogif, or maybe using 'convert', which is part of the ImageMagick set of graphics tools. I haven't had to configure squid for a few years, either, and i can't remember the details of how it works now, but you may be able to work out a way to dynamically rewrite the html files and change the jpeg file names to your gif file names - and then, of course, to make sure requests for those files are intercepted and the required jpegs requested and converted to gifs and sent to the browser. It's horribly complicated, but i'm sure there's a way to do it. The fact that you have to ask, though, suggests it will be an uphill struggle for you. Having written that, it occurs to me that you may be better off using apache as the proxy and doing the html rewriting and graphics processing in php. Without really looking into it too far, i think i'd find it reasonably simple to do it that way myself - where i'd probably be struggling with the squid route. Have fun! And if you want to contract it out, give me a yell (just remove the "xxxx.") from my email address - it sounds like it could be quite interesting! ;-) -- http://NovemberEchoRomeoDelta.com
From: Unruh on 22 Dec 2008 16:09 In uk.comp.os.linux you write: >Dear All, >For a research project I need to set up a PC which can >a) Accept incoming phone calls through a modem, set up a PPP >connection, and bridge across to a standard broadband connection >through a router (ie being an ISP for one other computer) and Totally standard. For setting up ppp see www.theory.physics.ubc.ca and for forwarding the IP messages, set up IP Forwarding. >b) run a web proxy which can convert all JPGs into GIFs and modify the >pages it's passing on appropriately - not unlike T-Mobile does when it >replaces images with lo-res versions. It would also be useful if it >could block all flash content and replace it with an icon saying >"Flash content blocked". Set up a php page. Passing on to where? >Can anyone point me in the direction of Linux stuff to do this? I'm >afraid the purpose has to be confidential for now, but if anyone who >could help really feels a need to know, email me and I'll tell you >what I can. >Ian
From: Unruh on 22 Dec 2008 16:11 Will Kemp <will(a)xxxx.swaggie.net> writes: >Ian wrote: >> Dear All, >> >> For a research project I need to set up a PC which can >> >> a) Accept incoming phone calls through a modem, set up a PPP >> connection, and bridge across to a standard broadband connection >> through a router (ie being an ISP for one other computer) and >> >> b) run a web proxy which can convert all JPGs into GIFs and modify the >> pages it's passing on appropriately - not unlike T-Mobile does when it >> replaces images with lo-res versions. It would also be useful if it >> could block all flash content and replace it with an icon saying >> "Flash content blocked". >> >> Can anyone point me in the direction of Linux stuff to do this? I'm >> afraid the purpose has to be confidential for now, but if anyone who >> could help really feels a need to know, email me and I'll tell you >> what I can. >Well, considering how many times i've set up this sort of thing, i'm >surprised at how much of a struggle it is to remember how to do it. >Mercifully it's been quite a few years since i had to set up a dial-in >ppp service! >The connection basics require a getty and pppd. A "getty" initialises >the modem and monitors the serial port(s) and sets up a connection when >someone dials in. Basically it just needs to start pppd when it gets a >connection. pppd will set up the IP connection (using IPCP) and do the >authentication (using PAP, probably, or maybe CHAP). >We used to use mgetty in the old days, but i notice agetty is shipped >with Fedora (but not mgetty), so that's probably the thing to use now. NO DO NOT USE AGETTY. use mgetty. That is the standard for dial in modem handling. I find it hard to believe that Fedora does not have mgetty. >You need to read the agetty and pppd man pages to find out what options >to use etc. You may also find a HOWTO or two that help. >Replacing jpegs with gifs is a bit more challenging, but you may find a >way to do it with transparent proxying (using iptables), using squid as >the proxy and passing the images through jpegtopnm and then pipe the >output through ppmtogif, or maybe using 'convert', which is part of the >ImageMagick set of graphics tools. >I haven't had to configure squid for a few years, either, and i can't >remember the details of how it works now, but you may be able to work >out a way to dynamically rewrite the html files and change the jpeg file >names to your gif file names - and then, of course, to make sure >requests for those files are intercepted and the required jpegs >requested and converted to gifs and sent to the browser. It's horribly >complicated, but i'm sure there's a way to do it. The fact that you have >to ask, though, suggests it will be an uphill struggle for you. >Having written that, it occurs to me that you may be better off using >apache as the proxy and doing the html rewriting and graphics processing >in php. Without really looking into it too far, i think i'd find it >reasonably simple to do it that way myself - where i'd probably be >struggling with the squid route. >Have fun! >And if you want to contract it out, give me a yell (just remove the >"xxxx.") from my email address - it sounds like it could be quite >interesting! ;-) >-- >http://NovemberEchoRomeoDelta.com
From: Will Kemp on 22 Dec 2008 16:26
Unruh wrote: > Will Kemp <will(a)xxxx.swaggie.net> writes: > >> Ian wrote: >>> Dear All, >>> >>> For a research project I need to set up a PC which can >>> >>> a) Accept incoming phone calls through a modem, set up a PPP >>> connection, and bridge across to a standard broadband connection >>> through a router (ie being an ISP for one other computer) and >>> >>> b) run a web proxy which can convert all JPGs into GIFs and modify the >>> pages it's passing on appropriately - not unlike T-Mobile does when it >>> replaces images with lo-res versions. It would also be useful if it >>> could block all flash content and replace it with an icon saying >>> "Flash content blocked". >>> >>> Can anyone point me in the direction of Linux stuff to do this? I'm >>> afraid the purpose has to be confidential for now, but if anyone who >>> could help really feels a need to know, email me and I'll tell you >>> what I can. > > >> Well, considering how many times i've set up this sort of thing, i'm >> surprised at how much of a struggle it is to remember how to do it. >> Mercifully it's been quite a few years since i had to set up a dial-in >> ppp service! > >> The connection basics require a getty and pppd. A "getty" initialises >> the modem and monitors the serial port(s) and sets up a connection when >> someone dials in. Basically it just needs to start pppd when it gets a >> connection. pppd will set up the IP connection (using IPCP) and do the >> authentication (using PAP, probably, or maybe CHAP). > >> We used to use mgetty in the old days, but i notice agetty is shipped >> with Fedora (but not mgetty), so that's probably the thing to use now. > > NO DO NOT USE AGETTY. use mgetty. Why? I'm sure there was a reason why we used mgetty and not agetty, but it's so long ago, i can't remember now. -- http://NovemberEchoRomeoDelta.com |