26 lines
1009 B
Plaintext
26 lines
1009 B
Plaintext
PPPoPPTP-Android plugin
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=======================
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This plugin was written for AOSP project from scratch. It has nothing to do with
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accel-pptp plugin [1].
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This plugin adds support for upstream kernel PPTP implementation in pppd daemon.
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Only PNS (client) part of PPTP is implemented, as we don't use Android devices
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in PAC mode.
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In general case, the execution flow for VPN startup on Android devices is:
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1. Run PPTP client (mtpd)
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2. mtpd obtains remote Call ID on OCRP (Outgoing-Call-Reply) packet
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3. mtpd creates PPTP socket
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4. mtpd runs pppd, passing PPTP socket as to pppopptp-android (as parameter)
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5. pppd dlopen() pppopptp-android plugin (because it received corresponding
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arguments from mtpd)
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Main task of this plugin is to obtain PPTP socket FD from mtpd and pass it
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back to pppd when .connect() callback is executed.
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All control packets are handled in mtpd. PPP packets (like LCP) are handled in
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pppd. Data packets are handled by kernel PPTP driver.
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[1] http://accel-pptp.sourceforge.net/
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