[tor-commits] [sbws/master] docs: explain how the second relay is selected

Sat Feb 23 10:57:25 UTC 2019

commit c5223ae0756489c6c84da6a60465cbab60094ad9
Author: juga0 <juga at riseup.net>
Date:   Thu Feb 7 10:52:36 2019 +0000

    docs: explain how the second relay is selected
---
 docs/source/activity_second_relay.puml       | 30 ++++++++++++++++++++++++++++
 docs/source/images/activity_second_relay.svg |  1 +
 docs/source/specification.rst                | 18 +++++++++++++++++
 3 files changed, 49 insertions(+)

diff --git a/docs/source/activity_second_relay.puml b/docs/source/activity_second_relay.puml
new file mode 100644
index 0000000..d088d68
--- /dev/null
+++ b/docs/source/activity_second_relay.puml
@@ -0,0 +1,30 @@
+ at startuml
+
+start
+
+if (relay to measure is exit?) then (yes)
+  :obtain non-exits;
+else (no)
+  :obtain an exits
+  without bad flag
+  that can exit
+  to port 443;
+endif
+:potential second relays;
+:obtain a relay
+from potential
+sencond relays
+randomly;
+if (second relay has 2x bandwidth?) then (yes)
+elseif (other second relay has 1.5x bandwidth?) then (yes)
+elseif (other second relay has 1x bandwidth?) then (yes)
+else (nothing)
+  stop
+endif
+:second relay selected!;
+:Build a circuit
+whith exit as
+second hop;
+stop
+
+ at enduml
\ No newline at end of file
diff --git a/docs/source/images/activity_second_relay.svg b/docs/source/images/activity_second_relay.svg
new file mode 100644
index 0000000..a996c1e
--- /dev/null
+++ b/docs/source/images/activity_second_relay.svg
@@ -0,0 +1 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?><svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" contentScriptType="application/ecmascript" contentStyleType="text/css" height="625px" preserveAspectRatio="none" style="width:812px;height:625px;" version="1.1" viewBox="0 0 812 625" width="812px" zoomAndPan="magnify"><defs><filter height="300%" id="fd9ikek" width="300%" x="-1" y="-1"><feGaussianBlur result="blurOut" stdDeviation="2.0"/><feColorMatrix in="blurOut" result="blurOut2" type="matrix" values="0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 .4 0"/><feOffset dx="4.0" dy="4.0" in="blurOut2" result="blurOut3"/><feBlend in="SourceGraphic" in2="blurOut3" mode="normal"/></filter></defs><g><ellipse cx="415" cy="20" fill="#000000" filter="url(#fd9ikek)" rx="10" ry="10" style="stroke: none; stroke-width: 1.0;"/><polygon fill="#FEFECE" filter="url(#fd9ikek)" points="344,50,486,50,498,62,486,74,344,74,332,62,344,50" style="stroke: #A80036; stroke-width: 1.5;"/>
 <text fill="#000000" font-family="sans-serif" font-size="11" lengthAdjust="spacingAndGlyphs" textLength="142" x="344" y="65.8081">relay to measure is exit?</text><text fill="#000000" font-family="sans-serif" font-size="11" lengthAdjust="spacingAndGlyphs" textLength="20" x="312" y="59.4058">yes</text><text fill="#000000" font-family="sans-serif" font-size="11" lengthAdjust="spacingAndGlyphs" textLength="14" x="498" y="59.4058">no</text><rect fill="#FEFECE" filter="url(#fd9ikek)" height="33.9688" rx="12.5" ry="12.5" style="stroke: #A80036; stroke-width: 1.5;" width="121" x="261.5" y="84"/><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="101" x="271.5" y="105.1387">obtain non-exits</text><rect fill="#FEFECE" filter="url(#fd9ikek)" height="75.875" rx="12.5" ry="12.5" style="stroke: #A80036; stroke-width: 1.5;" width="121" x="447.5" y="84"/><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" 
 textLength="93" x="457.5" y="105.1387">obtain an exits</text><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="101" x="457.5" y="119.1074">without bad flag</text><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="79" x="457.5" y="133.0762">that can exit</text><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="71" x="457.5" y="147.0449">to port 443</text><polygon fill="#FEFECE" filter="url(#fd9ikek)" points="415,165.875,427,177.875,415,189.875,403,177.875,415,165.875" style="stroke: #A80036; stroke-width: 1.5;"/><rect fill="#FEFECE" filter="url(#fd9ikek)" height="33.9688" rx="12.5" ry="12.5" style="stroke: #A80036; stroke-width: 1.5;" width="167" x="331.5" y="209.875"/><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="147" x="341.5" y="231.0137">potential second relays<
 /text><rect fill="#FEFECE" filter="url(#fd9ikek)" height="75.875" rx="12.5" ry="12.5" style="stroke: #A80036; stroke-width: 1.5;" width="115" x="357.5" y="263.8438"/><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="86" x="367.5" y="284.9824">obtain a relay</text><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="88" x="367.5" y="298.9512">from potential</text><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="95" x="367.5" y="312.9199">sencond relays</text><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="57" x="367.5" y="326.8887">randomly</text><polygon fill="#FEFECE" filter="url(#fd9ikek)" points="32,359.7188,215,359.7188,227,371.7188,215,383.7188,32,383.7188,20,371.7188,32,359.7188" style="stroke: #A80036; stroke-width: 1.5;"/><text fill="#000000" font-family="san
 s-serif" font-size="11" lengthAdjust="spacingAndGlyphs" textLength="20" x="127.5" y="393.9292">yes</text><text fill="#000000" font-family="sans-serif" font-size="11" lengthAdjust="spacingAndGlyphs" textLength="183" x="32" y="375.5269">second relay has 2x bandwidth?</text><polygon fill="#FEFECE" filter="url(#fd9ikek)" points="259,359.7188,487,359.7188,499,371.7188,487,383.7188,259,383.7188,247,371.7188,259,359.7188" style="stroke: #A80036; stroke-width: 1.5;"/><text fill="#000000" font-family="sans-serif" font-size="11" lengthAdjust="spacingAndGlyphs" textLength="20" x="377" y="393.9292">yes</text><text fill="#000000" font-family="sans-serif" font-size="11" lengthAdjust="spacingAndGlyphs" textLength="228" x="259" y="375.5269">other second relay has 1.5x bandwidth?</text><polygon fill="#FEFECE" filter="url(#fd9ikek)" points="531,359.7188,748,359.7188,760,371.7188,748,383.7188,531,383.7188,519,371.7188,531,359.7188" style="stroke: #A80036; stroke-width: 1.5;"/><text fill="#000000" font
 -family="sans-serif" font-size="11" lengthAdjust="spacingAndGlyphs" textLength="20" x="643.5" y="393.9292">yes</text><text fill="#000000" font-family="sans-serif" font-size="11" lengthAdjust="spacingAndGlyphs" textLength="217" x="531" y="375.5269">other second relay has 1x bandwidth?</text><text fill="#000000" font-family="sans-serif" font-size="11" lengthAdjust="spacingAndGlyphs" textLength="42" x="760" y="369.1245">nothing</text><ellipse cx="795" cy="413.1211" fill="none" filter="url(#fd9ikek)" rx="10" ry="10" style="stroke: #000000; stroke-width: 1.0;"/><ellipse cx="795.5" cy="413.6211" fill="#000000" filter="url(#fd9ikek)" rx="6" ry="6" style="stroke: none; stroke-width: 1.0;"/><rect fill="#FEFECE" filter="url(#fd9ikek)" height="33.9688" rx="12.5" ry="12.5" style="stroke: #A80036; stroke-width: 1.5;" width="163" x="333.5" y="463.1211"/><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="143" x="343.5" y="484.2598">second relay
  selected!</text><rect fill="#FEFECE" filter="url(#fd9ikek)" height="61.9063" rx="12.5" ry="12.5" style="stroke: #A80036; stroke-width: 1.5;" width="104" x="363" y="517.0898"/><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="84" x="373" y="538.2285">Build a circuit</text><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="78" x="373" y="552.1973">whith exit as</text><text fill="#000000" font-family="sans-serif" font-size="12" lengthAdjust="spacingAndGlyphs" textLength="74" x="373" y="566.166">second hop</text><ellipse cx="415" cy="608.9961" fill="none" filter="url(#fd9ikek)" rx="10" ry="10" style="stroke: #000000; stroke-width: 1.0;"/><ellipse cx="415.5" cy="609.4961" fill="#000000" filter="url(#fd9ikek)" rx="6" ry="6" style="stroke: none; stroke-width: 1.0;"/><line style="stroke: #A80036; stroke-width: 1.5;" x1="332" x2="322" y1="62" y2="62"/><line style="stroke: #A80036; st
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\ No newline at end of file
diff --git a/docs/source/specification.rst b/docs/source/specification.rst
index 1e5b683..56bd8b1 100644
--- a/docs/source/specification.rst
+++ b/docs/source/specification.rst
@@ -132,6 +132,24 @@ Measuring relays
 
 Source code: :func:`sbws.core.scanner.measure_relay`
 
+Selecting a second relay
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+#. If the relay to measure is an exit, use it as an exit and obtain the
+   non-exits.
+#. If the relay to measure is not an exit, use it as first hop and obtain
+   the exits.
+#. From non-exits or exits, select one randomly from the ones that have
+   double consensus bandwidth than the relay to measure.
+#. If there are no relays that satisfy this, lower the required bandwidth.
+
+.. image:: ./images/activity_second_relay.svg
+   :alt: activity select second relay
+   :height: 400px
+   :align: center
+
+Source code: :func:`sbws.core.scanner.measure_relay`
+
 Simple result storage
 ~~~~~~~~~~~~~~~~~~~~~
 



