978707 - B2G NFC: sessionToken can be used to get NFCPeer and NFCTag object

Status: RESOLVED FIXED

(Firefox OS Graveyard :: NFC, defect)

Description

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

This bug is related to Bug 963533, maybe we could duplicate this bug to Bug 963533 in the future, right now I just filed it as a seperate bug.

Currently we can get sessionToken from nfc-manager-tech-discovered system message, inside this message has a property called 'sessionToken', and we could use this sessionToken to get NFCTag or NFCPeer object. (This also prevents the Structured Clone problem). And Gaia app will check if 'P2P' is contained in the techList property, if it is, the Gaia app should use mozNfc.getPeer(sessionToken), otherwise it should use mozNfc.getTag(sessionToken). However if the app doesn't do this correctly, 


// Supposed the sessionToken is from a NFC Tag.

var nfcTag = mozNfc.getTag(sessionToken); 
// doing tag functionalities.

var nfcTag = mozNfc.getPeer(sessionToken); // Should we allow app the get a NFCPeer here, ever the session is actually referring to a NFC Tag.

Or should we let app could do this freely?

Comment 1

[Garner Lee]

Also related to Bug 963541. I believe we should enforce a close session before allowing switching with get{Technology}, or automatically close it. I prefer a throw just to make it clear to the programmer. 

Question then becomes, enforce this at external/nfcd, or in system/gonk?

Comment 2

[Garner Lee]

As referenced above, see also https://bugzilla.mozilla.org/show_bug.cgi?id=963533#c5

Comment 4

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

Reopen for this should have some fix in Gecko Chrome process, Bug 963533 should focus on WebAPI level.

Comment 5

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

Attachment: Patch

Comment 6

[Dimi Lee [:dimi]]

Comment on attachment 8516568 [details] [diff] [review]
Patch

Review of attachment 8516568 [details] [diff] [review]:
-----------------------------------------------------------------

::: dom/nfc/gonk/Nfc.js
@@ +315,5 @@
> +          let sessionToken = message.data.sessionToken;
> +          let sessionId = SessionHelper.getId(sessionToken);
> +          if (!SessionHelper.isValidToken(sessionToken) ||
> +              message.data.isP2P !== SessionHelper.isP2PSession(sessionId)) {
> +            debug("Received invalid Session Token: " + sessionToken);

From the idea here it looks like a "valid" session token stands for session token exists, and its type(isP2P) should be also correct. If this is the case, maybe we could just use:
SessionHelper.isValidToken(sessionToken, type) to do the check.

But make the API simple is also ok for me, just propose another idea.

Comment 7

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

Attachment: Patch v2.

merged into one function, r? to Dimi again.

Comment 8

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

https://hg.mozilla.org/integration/b2g-inbound/rev/798710d73edc

Comment 9

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/798710d73edc