[arch-projects] [projects][PATCH] wpa_actiond: Wait for three "failed" PONGs before disconnecting

[Emil Velikov]

On 21 August 2017 at 10:34, Emil Velikov <emil.l.velikov at gmail.com> wrote:
> When the system is very low on resources, select() may return 0 even
> when wpa_supplicant is alive and kicking.
>
> Don't disconnect as soon at that occurs - wait three times and clearly
> log it.
>
> Signed-off-by: Emil Velikov <emil.l.velikov at gmail.com>
> ---
> Hi all,
>
> Using [projects] since [wpa_actiond] gets kicked by the email filter.
> Can anyone update the message to include a list of supported tags, or
> link to an article/wiki with information?
>
> Back on topic:
>
> This is a small patch I had for 2 months and I thought about getting
> upstreamed.
>
> In particular - on certain workloads my system can get really low on
> memory (and available fds).
>
> With the patch in place, wpa_actiond no longer kills my connection
> although in practise I never seen two consecutive "wpa_supplicant failed
> to reply (PONG)" messages.
>
> My patch could be completely bonkers, so any suggestions how to address
> this correctly will be appreciated.
> ---
>  wpa_actiond.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/wpa_actiond.c b/wpa_actiond.c
> index d60d885..03a9d7f 100644
> --- a/wpa_actiond.c
> +++ b/wpa_actiond.c
> @@ -292,6 +292,7 @@ static void loop(const char *iface, const char *ctrlpath, const int disconnect_t
>    /* path to control socket */
>    char *ctrlsock = NULL;
>    int ctrlsocklen;
> +  int pong_failures = 0;
>
>    ssid[0] = '\0';
>    old_ssid[0] = '\0';
> @@ -359,6 +360,7 @@ static void loop(const char *iface, const char *ctrlpath, const int disconnect_t
>          }
>          logevent(WPA_ACTIOND_LOG_TERMINATE, iface, "");
>          state = WPA_ACTIOND_STATE_TERMINATED;
> +        pong_failures = 0;
>          break;
>        case 0:
>          if (state == WPA_ACTIOND_STATE_CONNECTION_LOST) {
> @@ -372,8 +374,15 @@ static void loop(const char *iface, const char *ctrlpath, const int disconnect_t
>              reply_len = 0;
>            reply[reply_len] = '\0';
>            if(!str_match(reply, "PONG")) {
> +            if (pong_failures <= 3) {
> +              logevent(WPA_ACTIOND_LOG_CUSTOM_ERROR, iface, "wpa_supplicant failed to reply (PONG)");
> +              pong_failures++;
> +              break;
> +            }
> +
>              /* supplicant has been terminated */
>              if(state == WPA_ACTIOND_STATE_CONNECTED || state == WPA_ACTIOND_STATE_CONNECTION_LOST) {
> +              logevent(WPA_ACTIOND_LOG_CUSTOM_ERROR, iface, "wpa_supplicant failed to reply three times in a row - disconnecting");
>                logevent(WPA_ACTIOND_LOG_DISCONNECTED, iface, ssid);
>                action(WPA_ACTIOND_ACTION_DISCONNECT, iface, ssid, idstr, wpa_ctrl_get_fd(ctrl), script);
>              }
> @@ -381,6 +390,7 @@ static void loop(const char *iface, const char *ctrlpath, const int disconnect_t
>              state = WPA_ACTIOND_STATE_TERMINATED;
>            }
>          }
> +        pong_failures = 0;
>          break;
>        default:
>          /* event received */
> @@ -446,6 +456,7 @@ static void loop(const char *iface, const char *ctrlpath, const int disconnect_t
>              /* we are not interested in this event */
>              break;
>          }
> +        pong_failures = 0;
>      }
>    }
>
> --
Humble ping anyone?

Thanks
Emil