Re: [lwip-users] Packet queuing to an ARP table entry
Amena El Homsi wrote: I am trying to send ping request using Lwip. The ICMP header and ping data is in my system frame memory referenced by a PBUF_ROM 'p' (p->payload points to the ICMP hdr in the frame memory. Is this correct? How long is the contents of this buffer stable? PBUF_ROM means ROM - i.e. stable for very long, not just until you think normal transmission is done. This is *not* very common! The PBUF_ROM is chained by a PBUF_RAM 'q' in which the ETHERNET and IP headers are saved [..] When I tried to send the first ping, LwIP sends an ARP request and queue the packet. The problem is that LwIP creates a new pbuf RAM 'r' and copies 'q' of type PBUF RAM and 'p' of type PBUF_ROM to the new PBUF RAM! I guess it's like that since your case is just very uncommon. Noone has ever bothered to improve for this. Normally, even if you have PBUF_ROM pbufs at some point, they are not the first frames sent to some devices. Plus it's normally not worth to improve for not copying here. Indeed I don't want to copy PBUF_ROM payload to the new PBUF_RAM, is there a way to avoid such copy? why LwIP doesn't copy 'q' to 'r' while preserving the chain between the PBUF_RAM and PBUF_ROM? Now this might work for the special case where the last pbuf(s) in a chain are ROM (remember we need to copy all non-ROM pbufs). We could of course create a new ROM pbuf referencing the same data, which would prevent copying. May I ask why it's worth making this change? I.e. does it really hurt performance or memory constraints in your case? Simon ___ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
Re: [lwip-users] lwip stats tcp cachehit
Markus Pischinger wrote: what does the "cachehit" in tcp stats refer to? It just means that the input pcb (active or listening) was the first in the list. Not too interesting... I got some "proterr" aswell but as far as i've seen they occur when i get a packet while not having an active connection, is that correct? Yes. Simon ___ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
[lwip-users] Packet queuing to an ARP table entry
Hi, I am using lwip 2.0.3 Release version. I am trying to send ping request using Lwip. The ICMP header and ping data is in my system frame memory referenced by a PBUF_ROM 'p' (p->payload points to the ICMP hdr in the frame memory. The PBUF_ROM is chained by a PBUF_RAM 'q' in which the ETHERNET and IP headers are saved q: q->next = p p: p->next = NULL q->payload = q + sizeof(struct pbuf)p->payload = memory address q->len = Eth hdr size + IP hdr size p->len = ICMP hdr size + ping data size q->tot_len = q->len + p->len p->tot_len = p->len q->type = PBUF_RAM p->type = PBUF_ROM When I tried to send the first ping, LwIP sends an ARP request and queue the packet. The problem is that LwIP creates a new pbuf RAM 'r' and copies 'q' of type PBUF RAM and 'p' of type PBUF_ROM to the new PBUF RAM! Indeed I don't want to copy PBUF_ROM payload to the new PBUF_RAM, is there a way to avoid such copy? why LwIP doesn't copy 'q' to 'r' while preserving the chain between the PBUF_RAM and PBUF_ROM? Regards, Amena -- Amena El-Homsi Computer & Communication Engineer Dipl. Eng, M.S. ___ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
Re: [lwip-users] httpd: how to implement AJAX
Il 14/11/2017 13:54, Noam Weissman ha scritto: Hi, HTTPD is widely used and if you look around you can find examples from ST micro TI and other vendors. Do you mean HTTPD *without* a secure layer? Yes, I know there are many examples of it, but IMHO because it is simpler than a full HTTPS server. I don't think you can use a non-secure HTTP (or MQTT or SNMP) communication in a public network today for a serious application that isn't a simple test example. ___ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
Re: [lwip-users] httpd: how to implement AJAX
Hi, HTTPD is widely used and if you look around you can find examples from ST micro TI and other vendors. The examples that you will find are probably older versions with no POST or AJAX support but they work ! Noam. -Original Message- From: lwip-users [mailto:lwip-users-bounces+noam=silrd@nongnu.org] On Behalf Of Giuseppe Modugno Sent: Tuesday, November 14, 2017 2:47 PM To: lwip-users@nongnu.org Subject: Re: [lwip-users] httpd: how to implement AJAX Il 13/11/2017 21:25, goldsi...@gmx.de ha scritto: > Giuseppe Modugno wrote: >> The prototype for SSI callbacks is: >> [..] >> I don't see any reference to query string parameters. So how to >> select the right action? > > Sorry for the confusion. This is a mix of resource optimization, > missing documentation and maybe missing framework functions. Thank you very much for your explanation. Now it is clear. > My plan is to have https examples for the next release... https would be very interesting (actually a simple non-secure http server isn't really useable in public Internet). If I understood correctly, https means ssl/tls. So the first task is to add SSL/TLS to lwip, right? It's a pity lwip doesn't feature those secure network layers. ___ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users ___ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
Re: [lwip-users] httpd: how to implement AJAX
Hi,
Yes I use a different server. My server code was based on a variation of the
httpd code +
many additions.
I use POST to send the user+password and no it is not encoded... this is mainly
for simple use.
The SSID is not a cookie... The SSID's are handles in a separate task that does
the house keeping.
Regarding the single file trick you may be right but this is how it works for
me and I OK with it :)
Regarding the GET/POST params... as the server parses the URL it also parses
the GET params.
BR,
Noam.
From: lwip-users [mailto:lwip-users-bounces+noam=silrd@nongnu.org] On
Behalf Of Giuseppe Modugno
Sent: Tuesday, November 14, 2017 2:42 PM
To: lwip-users@nongnu.org
Subject: Re: [lwip-users] httpd: how to implement AJAX
Il 13/11/2017 18:04, Noam Weissman ha scritto:
Yes SSID is a session ID that had been added to my own server code.
So are you using a completely different HTTP server from the httpd that is in
apps folder of lwip main source?
When a user askes for a page and there is no ssid the server will redirect
(send a 303)
And load a login page instead. After the user writes user+password the data is
sent to
The server.
How do you send user+password to the server? PUT? Do you encode these sensible
values?
The server call's external code to check for validity of user+pass... if OK it
Request a new ssid from a separate task.
After that the web server sends the previously request page + ssid... every
operation
at the browser side must add that ssid value.
Is it a cookie, right?
Every time the web server gets a request
with the correct ssid it clears the related timeout. If the ssid timeouts and
the user asks
for some data it will again redirect to the login page.
Do you call a specific function from main at regular intervals to clear all
SSID that expire?
Regarding AJAX:
How do you handle SSI ?... I am doing it differently ? I have something like
this in my code:
const SSI_t SSI_Table[] =
{
{"mem_rout", mem_routing},
{"IOSel", IO_Selection},
{"get_users", get_users},
{"ajax_reply", AjaxReply},
{NULL, NULL} // last tag must always be NULL to close the list
};
mem_routing, IO_Selection, get_users, and AjaxReply are call-back function
that are called by the web
server as a result of encountering the proper tag... for mem_routing it is
I think LWIP_HTTPD_CUSTOM_FILES is simpler to use when you have a file that is
completely dynamic. Your "single tag trick" works, but IMHO is too complex for
what you have to do.
my AjaxReply parses the GET params and after that does something like that:
How AjaxReply() function could access GET params if they aren't accessible from
the SSI handler? Most probably the answer is in the file state
(LWIP_HTTPD_FILE_STATE) that is filled by httpd_cgi_handler() callback (as
explained by goldsimon).
// get action param
Char *Action = some_function();
If(strcmp(Action, "do_something_1") == 0)
{
}
elses If(strcmp(Action, "do_something_2") == 0)
{
}
else
{
// print a debug error : action unknown
}
Hope that helped,
Noam.
From: lwip-users [mailto:lwip-users-bounces+noam=silrd@nongnu.org] On
Behalf Of Giuseppe Modugno
Sent: Monday, November 13, 2017 6:09 PM
To: lwip-users@nongnu.org
Subject: Re: [lwip-users] httpd: how to implement AJAX
Il 13/11/2017 14:34, Noam Weissman ha scritto:
Hi,
I am using the following technic for AJAX.
Create an empty file named ajax.shtml or ajax.html and add it to your file list.
Inside the file you only write one tag without anything else. For example
Do not add CR or LF just the tag !!.
Now when you issue an AJAX call the WEB server opens the file, reads it and
send its data.
Because the file has only the tag it will parse it, call your handler for that
tag and send back
To the browser just your data !!
Ok, so you use SSI to create dynamic data. I tried with custom files, because
*all the content* is dynamic (and not only some parts, defined by specific
tags).
If you use Juery it will look something like this... actually a function used
as an event handler in
my own code:
function resetIO()
{
//Remove the dialog
returnToPage();
$.ajax({
url: "ajax.shtml",
dataType : "text",
type : "GET",
cache : false,
data : ({
ssid: ssid,
a: 'opReset',
type: 2
}),
error : function()
{
showMessage("Network Error: Sorry, there was a problem connecting
to the server.");
},
success : function(result)
{
window.location.href = document.location;
}
});
}
In the above data you have the a: variable, this is your AJAX action !.
If I understood well, data is translated in query string, in your example:
GET ajax.shtml?ssid=&a=opReset&type=2
Of course, is the value of
Re: [lwip-users] httpd: how to implement AJAX
Giuseppe Modugno wrote: > It's a pity lwip doesn't feature those >secure network layers. Actually, it's not that far away. Have a look at the for master. It's not in the releases, yet. Simon ___ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
Re: [lwip-users] httpd: how to implement AJAX
Il 13/11/2017 21:25, goldsi...@gmx.de ha scritto: Giuseppe Modugno wrote: The prototype for SSI callbacks is: [..] I don't see any reference to query string parameters. So how to select the right action? Sorry for the confusion. This is a mix of resource optimization, missing documentation and maybe missing framework functions. Thank you very much for your explanation. Now it is clear. My plan is to have https examples for the next release... https would be very interesting (actually a simple non-secure http server isn't really useable in public Internet). If I understood correctly, https means ssl/tls. So the first task is to add SSL/TLS to lwip, right? It's a pity lwip doesn't feature those secure network layers. ___ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
Re: [lwip-users] httpd: how to implement AJAX
Il 13/11/2017 18:04, Noam Weissman ha scritto:
Yes SSID is a session ID that had been added to my own server code.
So are you using a completely different HTTP server from the httpd that
is in apps folder of lwip main source?
When a user askes for a page and there is no ssid the server will
redirect (send a 303)
And load a login page instead. After the user writes user+password the
data is sent to
The server.
How do you send user+password to the server? PUT? Do you encode these
sensible values?
The server call’s external code to check for validity of user+pass… if
OK it
Request a new ssid from a separate task.
After that the web server sends the previously request page + ssid…
every operation
at the browser side must add that ssid value.
Is it a cookie, right?
Every time the web server gets a request
with the correct ssid it clears the related timeout. If the ssid
timeouts and the user asks
for some data it will again redirect to the login page.
Do you call a specific function from main at regular intervals to clear
all SSID that expire?
Regarding AJAX:
How do you handle SSI ?... I am doing it differently ? I have
something like this in my code:
const SSI_t SSI_Table[] =
{
{"mem_rout", mem_routing},
{"IOSel", IO_Selection},
{"get_users", get_users},
{"ajax_reply", AjaxReply},
{NULL, NULL} // last tag must always be NULL to close the list
};
mem_routing, IO_Selection, get_users, and AjaxReply are call-back
function that are called by the web
server as a result of encountering the proper tag… for mem_routing it
is
I think LWIP_HTTPD_CUSTOM_FILES is simpler to use when you have a file
that is completely dynamic. Your "single tag trick" works, but IMHO is
too complex for what you have to do.
my AjaxReply parses the GET params and after that does something like
that:
How AjaxReply() function could access GET params if they aren't
accessible from the SSI handler? Most probably the answer is in the file
state (LWIP_HTTPD_FILE_STATE) that is filled by httpd_cgi_handler()
callback (as explained by goldsimon).
// get action param
Char *Action = some_function();
If(strcmp(Action, “do_something_1”) == 0)
{
}
elses If(strcmp(Action, “do_something_2”) == 0)
{
}
else
{
// print a debug error : action unknown
}
Hope that helped,
Noam.
*From:*lwip-users
[mailto:lwip-users-bounces+noam=silrd@nongnu.org] *On Behalf Of
*Giuseppe Modugno
*Sent:* Monday, November 13, 2017 6:09 PM
*To:* lwip-users@nongnu.org
*Subject:* Re: [lwip-users] httpd: how to implement AJAX
Il 13/11/2017 14:34, Noam Weissman ha scritto:
Hi,
I am using the following technic for AJAX.
Create an empty file named ajax.shtml or ajax.html and add it to your file list.
Inside the file you only write one tag without anything else. For example
Do not add CR or LF just the tag !!.
Now when you issue an AJAX call the WEB server opens the file, reads it and
send its data.
Because the file has only the tag it will parse it, call your handler for that
tag and send back
To the browser just your data !!
Ok, so you use SSI to create dynamic data. I tried with custom files,
because *all the content* is dynamic (and not only some parts, defined
by specific tags).
If you use Juery it will look something like this... actually a function used
as an event handler in
my own code:
function resetIO()
{
//Remove the dialog
returnToPage();
$.ajax({
url: "ajax.shtml",
dataType : "text",
type : "GET",
cache : false,
data : ({
ssid: ssid,
a: 'opReset',
type: 2
}),
error : function()
{
showMessage("Network Error: Sorry, there was a problem connecting to
the server.");
},
success : function(result)
{
window.location.href = document.location;
}
});
}
In the above data you have the a: variable, this is your AJAX action !.
If I understood well, data is translated in query string, in your example:
GET ajax.shtml?ssid=&a=opReset&type=2
Of course, is the value of ssid Javascript variable.
In your own SSI/CGI code you have a table with tags + callbacks... one of the
callback function
Is your AJAX handler. Inside it you create an if <> else layout and handle the
different actions.
The prototype for SSI callbacks is:
typedef u16_t (*tSSIHandler)(
#if LWIP_HTTPD_SSI_RAW
const char* ssi_tag_name,
#else /* LWIP_HTTPD_SSI_RAW */
int iIndex,
#endif /* LWIP_HTTPD_SSI_RAW */
char *pcInsert, int iInsertLen
#if LWIP_HTTPD_SSI_MULTIPART
, u16_t current_tag_part, u16_t
*next_tag_part
#endif /* LWIP_HTTPD_SSI_MULTIPART */
#if defined(LWIP_HTTPD_FILE_STATE) && LWIP_HTTPD_FILE_STATE
[lwip-users] lwip stats tcp cachehit
Hi guys, what does the "cachehit" in tcp stats refer to? I just checked my stats got the following: TCP xmit: 58754 recv: 58877 fw: 0 drop: 22 chkerr: 0 lenerr: 0 memerr: 0 rterr: 0 proterr: 22 opterr: 0 err: 0 cachehit: 58769 I got some "proterr" aswell but as far as i've seen they occur when i get a packet while not having an active connection, is that correct? Thanks in advance! Regards, Markus ___ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
