Hello Johnny, Thank you for the explanation. That's an important remark so I can continue the evaluation here.
I was thinking that the issue was related to the MQTT library. But, in fact, there is something wrong with the TCP connection. I will post here as soon as I have more news. Best regards, Flavio Em dom., 27 de jun. de 2021 às 13:56, Johnny Billquist <b...@softjar.se> escreveu: > > Something is seriously wrong in your first run. > Maybe a tcpdump would expose something, but basically, tcp_max_wrb_size > should never be 0, but in your first run it appears to be. > > As that is the buffer size to use, you end up with a tcp connection with > a buffer size of 0, so of course all writes (including send) will return > with success, but with 0 bytes written, since there wasn't space for > anything more. > > tcp_max_wrb_size should be based on mss, which suggests that mss would > be zero. But that is rather surprising. Since the mss is exchanged > between the hosts at tcp connection establishment, it would be very > interesting to report what mss each side is suggesting. > > It might be that one side isn't reporting any mss at all, and then the > tcp implementation in Nuttx behaves badly. I don't really have time to > dive into this more right now, but this should give you some pointers > and ideas to where to look further. > > Johnny > > On 2021-06-27 16:34, Flavio Castro Alves Filho wrote: > > I'm sorry ... I got the same behavior, but the send function now > > started to work non-blocking. > > > > Here is my situation: > > > > * I have 2 mqtt brokers (tcp servers) > > - one commercial (Tago.io) > > - one personal (Mosquitto) > > > > After a successful connection in both cases, the next step is to send > > the mqtt connect message. > > > > Below shows the execution trace for the commercial broker. > > > > [972934023.720000] [ INFO] psock_vfcntl: sockfd=0x10007a70 cmd=9 > > [972934023.730000] [ INFO] psock_tcp_send (0x1000a9ac): > > [972934023.730000] [ INFO] 0000 10 42 00 04 4d 51 54 54 04 c2 01 90 > > 00 07 54 65 .B..MQTT......Te > > [972934023.740000] [ INFO] 0010 73 74 65 47 57 00 07 70 68 69 74 61 > > 67 6f 00 24 steGW..phitago.$ > > [972934023.750000] [ INFO] 0020 30 66 30 62 36 37 33 64 2d 33 64 35 > > 66 2d 34 38 0f0b673d-3d5f-48 > > [972934023.760000] [ INFO] 0030 38 62 2d 62 38 62 36 2d 62 36 35 36 > > 35 66 37 39 8b-b8b6-b6565f79 > > [972934023.770000] [ INFO] 0040 66 32 66 64 > > f2fd > > [972934023.780000] [ INFO] tcp_max_wrb_size: tcp_max_wrb_size = 0 for > > conn 0x20006e78 > > [972934023.780000] [ INFO] psock_tcp_send: new wrb 0x200073fc (non > > blocking) > > [972934023.790000] [ INFO] iob_copyin_internal: iob=0x20004238 len=0 > > offset=0 > > > > The send() result is 0. And keeps always in this way. > > > > And below we have the traces for the personal broker transmission. > > > > [972932455.670000] [ INFO] psock_vfcntl: sockfd=0x10007a70 cmd=9 > > [972932455.670000] [ INFO] psock_tcp_send (0x1000a9ac): > > [972932455.680000] [ INFO] 0000 10 42 00 04 4d 51 54 54 04 c2 01 90 > > 00 07 54 65 .B..MQTT......Te > > [972932455.690000] [ INFO] 0010 73 74 65 47 57 00 07 70 68 69 74 61 > > 67 6f 00 24 steGW..phitago.$ > > [972932455.700000] [ INFO] 0020 30 66 30 62 36 37 33 64 2d 33 64 35 > > 66 2d 34 38 0f0b673d-3d5f-48 > > [972932455.710000] [ INFO] 0030 38 62 2d 62 38 62 36 2d 62 36 35 36 > > 35 66 37 39 8b-b8b6-b6565f79 > > [972932455.710000] [ INFO] 0040 66 32 66 64 > > f2fd > > [972932455.720000] [ INFO] tcp_max_wrb_size: tcp_max_wrb_size = 2144 > > for conn 0x20006e78 > > [972932455.730000] [ INFO] psock_tcp_send: new wrb 0x200073fc (non > > blocking) > > [972932455.740000] [ INFO] iob_copyin_internal: iob=0x20004238 len=68 > > offset=0 > > [972932455.750000] [ INFO] iob_copyin_internal: iob=0x20004238 > > avail=0 len=68 next=0 > > > > In this case, send return a value bigger than 0. > > > > Could you please give me any advice to understand what's going on? Or > > what can I check? > > > > The connect() response is 0 in both cases. > > > > Using PC-based tools, such as MQTT.Fx, I can connect to the host. > > > > Best regards, > > > > Flavio > > > > Em sáb., 26 de jun. de 2021 às 13:57, Gregory Nutt > > <spudan...@gmail.com> escreveu: > >> > >> > >>> Is there any chance that the broker didn't like the mqtt connect > >>> message and shutdown the connection and leaving my device alone ... > >>> all during send call? > >> If the peer disconnects, the socket should be marked disconnected and > >> the send() should fail with an error. > > > > > > > > -- > Johnny Billquist || "I'm on a bus > || on a psychedelic trip > email: b...@softjar.se || Reading murder books > pdp is alive! || tryin' to stay hip" - B. Idol -- Flavio de Castro Alves Filho flavio.al...@gmail.com Twitter: http://twitter.com/#!/fraviofii LinkedIn profile: www.linkedin.com/in/flaviocastroalves
