net: use stronger AddLocal() for our I2P address #21914

1. 
   vasild commented at 10:56 am on May 11, 2021: member

   There are two issues:

   1. Our I2P address not added to local addresses.

   • externalip= is used with an IPv4 address (this sets automatically discover=0)
   • No discover=1 is used
   • i2psam= is used
   • No externalip= is used for our I2P address
   • listenonion=1 torcontrol= are used

   In this case AddLocal(LOCAL_MANUAL) is used for our .onion address and AddLocal(LOCAL_BIND) for our .b32.i2p address, the latter being ignored due to discover=0.

   2. Our I2P address removed from local addresses even if specified with externalip= on I2P proxy restart.

   • externalip= is used with our I2P address (this sets automatically discover=0)
   • No discover=1 is used
   • i2psam= is used

   In this case, initially externalip= causes our I2P address to be added with AddLocal(LOCAL_MANUAL) which overrides discover=0 and works as expected. However, if later the I2P proxy is shut down we do RemoveLocal() in order to stop advertising our I2P address (since we have lost I2P connectivity). When the I2P proxy is started and we reconnect to it, restoring the I2P connectivity, we do AddLocal(LOCAL_BIND) which does nothing due to discover=0.

   To resolve those two issues, use AddLocal(LOCAL_MANUAL) for I2P which is also what we do with Tor.

2. net: use stronger AddLocal() for our I2P address

   There are two issues:
   
   1. Our I2P address not added to local addresses.
   
   * `externalip=` is used with an IPv4 address (this sets automatically
     `discover=0`)
   * No `discover=1` is used
   * `i2psam=` is used
   * No `externalip=` is used for our I2P address
   * `listenonion=1 torcontrol=` are used
   
   In this case `AddLocal(LOCAL_MANUAL)` is used for our `.onion` address
   and `AddLocal(LOCAL_BIND)` for our `.b32.i2p` address, the latter being
   ignored due to `discover=0`.
   
   2. Our I2P address removed from local addresses even if specified
   with `externalip=` on I2P proxy restart.
   
   * `externalip=` is used with our I2P address (this sets automatically
     `discover=0`)
   * No `discover=1` is used
   * `i2psam=` is used
   
   In this case, initially `externalip=` causes our I2P address to be added
   with `AddLocal(LOCAL_MANUAL)` which overrides `discover=0` and works as
   expected. However, if later the I2P proxy is shut down we do
   `RemoveLocal()` in order to stop advertising our I2P address (since we
   have lost I2P connectivity). When the I2P proxy is started and we
   reconnect to it, restoring the I2P connectivity, we do
   `AddLocal(LOCAL_BIND)` which does nothing due to `discover=0`.
   
   To resolve those two issues, use `AddLocal(LOCAL_MANUAL)` for I2P which
   is also what we do with Tor.

   105941b726
3. 
   vasild commented at 10:57 am on May 11, 2021: member

   The first issue was reported by @sdaftuar in #20685 (review), thanks!
4. DrahtBot added the label P2P on May 11, 2021
5. 
   jonatack commented at 11:17 am on May 11, 2021: member

   Concept ACK, thanks for following up on this.
6. 
   laanwj commented at 1:35 pm on May 13, 2021: member

   It makes sense to do the same for I2P as for Tor.

   Code review ACK 105941b726c078642e785ecb7b6834ba814381b0

7. laanwj merged this on May 13, 2021
8. laanwj closed this on May 13, 2021

   ---

9. vasild deleted the branch on May 13, 2021
10. sidhujag referenced this in commit bf77c70a58 on May 13, 2021
11. Fabcien referenced this in commit 9f22e70a42 on Feb 15, 2022
12. gwillen referenced this in commit 7275a1732e on Jun 1, 2022
13. DrahtBot locked this on Aug 16, 2022

Contributors
vasild jonatack laanwj

Labels
P2P