Forum: NGINX imap_client_buffer not being obeyed

I have imap_client_buffer set to 64k(as required by imap protocol) in 
the
nginx.conf file
However when an imap client sends a very long command, post 
authentication,
the length gets truncated at 4k(the default page size of the linux 
operating
system)

how can i debug this problem? i have stepped through the code using gdb. 
as
far as i can see, in mail_proxy module, the value of the conf 
file(120000
for testing) was correctly seen

gdb) p p->upstream.connection->data
$24 = (void *) 0x9e4bd48
(gdb) p s
$25 = (ngx_mail_session_t *) 0x9e4bd48
(gdb) p p->buffer->end
Cannot access memory at address 0x1c
(gdb) p s->buffer->end - s->buffer->last
$26 = 120000
(gdb) p s
$27 = (ngx_mail_session_t *) 0x9e4bd48
(gdb) n
205         pcf = ngx_mail_get_module_srv_conf(s, 
ngx_mail_proxy_module);
(gdb) n
207         s->proxy->buffer = ngx_create_temp_buf(s->connection->pool,
(gdb) p pcf
$28 = (ngx_mail_proxy_conf_t *) 0x9e3c480
(gdb) p *pcf
$29 = {enable = 1, pass_error_message = 1, xclient = 1, buffer_size =
120000,
  timeout = 86400000, upstream_quick_retries = 0, upstream_retries = 0,
  min_initial_retry_delay = 3000, max_initial_retry_delay = 3000,
  max_retry_delay = 60000}

When the command below is sent using telnet, only 4 k of data is 
accepted,
then nginx hangs until i hit enter on keyboard......after which the
truncated command is sent to the upstream imap server.

I am using nginx 0.78, is this a known issue?

This is the command sent

HP1L UID FETCH
344990,344996,344998,345004,345006,345010:345011,345015,345020,345043,345046,345049:345050,345053,345057:345059,345071,345080,345083,345085,345090,345092:345093,345096,345101:345102,345106,345112,345117,345136,345140,345142:345144,345146:345147,345150,345161,345163,345167,345174:345176,345195,345197,345203,345205,345207:345209,345214,345218,345221,345224,345229,345231,345233,345236,345239,345248,345264,345267,345272,345285,345290,345292,345301,345305,345308,345316,345320,345322,345324,345327,345358,345375,345384,345386,345391,345409,345427:345428,345430:345432,345434:345435,345437,345439,345443,345448,345450,345463,345468:345470,345492,345494,345499,345501,345504,345506,345515:345519,345522,345525,345535,345563,345568,345574,345577,345580,345582,345599,345622,345626,345630,345632:345633,345637,345640,345647:345648,345675,345684,345686:345687,345703:345704,345714:345717,345720,345722:345724,345726,345730,345734:345737,345749,345756,345759,345783,345785:345787,345790,345806:345807,3458
 12,345816,345720,345722:345724,345726,345730,345734:345737,345749,345756,345759,345783,345785:345787,345790,345806:345807,345812,345817,345902,345919,345953,345978,345981,345984,345990,345997,346004,346008:346009,346011:346012,346022,346039,346044,346050,346061:346062,346066:346067,346075:346076,346081,346088,346090,346093,346096,346098:346099,346110,346140,346170,346172:346174,346187,346189,346193:346194,346197,346204,346212,346225,346241,346244,346259,346323,346325:346328,346331:346332,346337:346338,346342,346346,346353,346361:346362,346364,346420,346426,346432,346447,346450:346451,346453:346454,346456:346457,346459:346460,346466:346468,346474,346476,346479,346483,346496,346498:346501,346504,346530,346539,346546,346576,346589:346590,346594:346595,346601,346607:346609,346612,346614:346615,346617:346618,346625,346631,346638,346641,346654,346657,346661,346665,346671,346687:346688,346693,346695,346734:346735,346741,346747:346748,346755,346757,346777,346779,346786:346788,346791,346793,
 346801,346815,346821:346822,346825,346828,346837,346839,346843,346848,346857:346858,346860,346862:346863,346866,346868:346869,346877,346883,346895:346897,346899,346923,346927,346945,346948,346961,346964:346966,346968,346970,346974,346987,346989:346990,346992,347000,347003,347008:347011,347013,347021,347028,347032:347034,347036,347049,347051,347058,347076,347079,347081,347083,347085,347092,347096,347108,347130,347145:347148,347150,347155:347158,347161,347163:347164,347181,347184,347187:347189,347204,347210:347211,347215,347217:347220,347227:347228,347234,347244,347246,347251,347253,347263:347264,347266,347268,347275,347292,347294,347304,347308,347317:347320,347322,347325:347327,347340:347341,347346,347352:347353,347357,347360:347361,347375,347379,347382:347386,347389,347392,347402,347405:347406,347411,347433:347434,347438,347440:347441,347443:347444,347448,347459:347460,347465,347468:347469,347476:347479,347490,347497,347506,347526,347530,347545,347547,347555:347556,347601:347605,347
 632,347634,347641,347643:347646,347649,347653,347660,347668,347676,347707,347719,347722,347724,347727:347732,347735,347746,347754,347756:347757,347761,347776,347779,347791,347798,347800,347805,347816:347817,347822,347837,347841,347843,347846,347848,347851,347879,347885,347892:347894,347903,347907:347911,347915:347916,347918,347950,347952:347953,347981,347986:347988,348001,348037:348038,348049,348052,348056:348058,348061,348072,348074,348077:348078,348080,348082,348100,348105,348109,348111:348116,348119:348123,348131:348132,348138,348150:348151,348153,348157,348161:348163,348166,348168:348169,348171,348173,348176,348178,348180:348181,348201,348204,348208,348218:348219,348222,348226,348229:348230,348235,348238:348240,348244:348247,348249,348251:348253,348256:348257,348263,348285,348288:348289,348293,348298:348299,348301:348302,348305:348306,348310,348327,348332:348337,348340,348342,348344,348348,348351:348353,348356:348357,348360,348366,348377,348386,348390,348398,348400:348401,348406
 :348407,348419,348422,348424,348427:348428,348430,348432:348433,348439,348444,348447:348448,348450:348451,348454,348456,348459:348460,348473,348493,348497:348498,348504,348506,348508,348516,348520,348527,348530,348532,348546:348547,348551,348560:348563,348567,348570:348572,348574,348577,348581,348588,348595,348610,348632,348636,348642,348646,348667,348672:348673,348679,348703,348713:348714,348716,348718:348722,348728:348729,348731,348735,348743:348745,348749,348751:348752,348759,348768,348773,348780:348781,348784:348791
(UID FLAGS)

Posted at Nginx Forum: 
http://forum.nginx.org/read.php?2,231439,231439#msg-231439

<pre>
HP1L UID FETCH
344990,344996,344998,345004,345006,345010:345011,345015,345020,345043,345046,345049:345050,345053,345057:345059,345071,345080,345083,345085,345090,345092:345093,345096,345101:345102,345106,345112,345117,345136,345140,345142:345144,345146:345147,345150,345161,345163,345167,345174:345176,345195,345197,345203,345205,345207:345209,345214,345218,345221,345224,345229,345231,345233,345236,345239,345248,345264,345267,345272,345285,345290,345292,345301,345305,345308,345316,345320,345322,345324,345327,345358,345375,345384,345386,345391,345409,345427:345428,345430:345432,345434:345435,345437,345439,345443,345448,345450,345463,345468:345470,345492,345494,345499,345501,345504,345506,345515:345519,345522,345525,345535,345563,345568,345574,345577,345580,345582,345599,345622,345626,345630,345632:345633,345637,345640,345647:345648,345675,345684,345686:345687,345703:345704,345714:345717,345720,345722:345724,345726,345730,345734:345737,345749,345756,345759,345783,345785:345787,345790,345806:345807,3458
 12,345816,345720,345722:345724,345726,345730,345734:345737,345749,345756,345759,345783,345785:345787,345790,345806:345807,345812,345817,345902,345919,345953,345978,345981,345984,345990,345997,346004,346008:346009,346011:346012,346022,346039,346044,346050,346061:346062,346066:346067,346075:346076,346081,346088,346090,346093,346096,346098:346099,346110,346140,346170,346172:346174,346187,346189,346193:346194,346197,346204,346212,346225,346241,346244,346259,346323,346325:346328,346331:346332,346337:346338,346342,346346,346353,346361:346362,346364,346420,346426,346432,346447,346450:346451,346453:346454,346456:346457,346459:346460,346466:346468,346474,346476,346479,346483,346496,346498:346501,346504,346530,346539,346546,346576,346589:346590,346594:346595,346601,346607:346609,346612,346614:346615,346617:346618,346625,346631,346638,346641,346654,346657,346661,346665,346671,346687:346688,346693,346695,346734:346735,346741,346747:346748,346755,346757,346777,346779,346786:346788,346791,346793,
 346801,346815,346821:346822,346825,346828,346837,346839,346843,346848,346857:346858,346860,346862:346863,346866,346868:346869,346877,346883,346895:346897,346899,346923,346927,346945,346948,346961,346964:346966,346968,346970,346974,346987,346989:346990,346992,347000,347003,347008:347011,347013,347021,347028,347032:347034,347036,347049,347051,347058,347076,347079,347081,347083,347085,347092,347096,347108,347130,347145:347148,347150,347155:347158,347161,347163:347164,347181,347184,347187:347189,347204,347210:347211,347215,347217:347220,347227:347228,347234,347244,347246,347251,347253,347263:347264,347266,347268,347275,347292,347294,347304,347308,347317:347320,347322,347325:347327,347340:347341,347346,347352:347353,347357,347360:347361,347375,347379,347382:347386,347389,347392,347402,347405:347406,347411,347433:347434,347438,347440:347441,347443:347444,347448,347459:347460,347465,347468:347469,347476:347479,347490,347497,347506,347526,347530,347545,347547,347555:347556,347601:347605,347
 632,347634,347641,347643:347646,347649,347653,347660,347668,347676,347707,347719,347722,347724,347727:347732,347735,347746,347754,347756:347757,347761,347776,347779,347791,347798,347800,347805,347816:347817,347822,347837,347841,347843,347846,347848,347851,347879,347885,347892:347894,347903,347907:347911,347915:347916,347918,347950,347952:347953,347981,347986:347988,348001,348037:348038,348049,348052,348056:348058,348061,348072,348074,348077:348078,348080,348082,348100,348105,348109,348111:348116,348119:348123,348131:348132,348138,348150:348151,348153,348157,348161:348163,348166,348168:348169,348171,348173,348176,348178,348180:348181,348201,348204,348208,348218:348219,348222,348226,348229:348230,348235,348238:348240,348244:348247,348249,348251:348253,348256:348257,348263,348285,348288:348289,348293,348298:348299,348301:348302,348305:348306,348310,348327,348332:348337,348340,348342,348344,348348,348351:348353,348356:348357,348360,348366,348377,348386,348390,348398,348400:348401,348406
 :348407,348419,348422,348424,348427:348428,348430,348432:348433,348439,348444,348447:348448,348450:348451,348454,348456,348459:348460,348473,348493,348497:348498,348504,348506,348508,348516,348520,348527,348530,348532,348546:348547,348551,348560:348563,348567,348570:348572,348574,348577,348581,348588,348595,348610,348632,348636,348642,348646,348667,348672:348673,348679,348703,348713:348714,348716,348718:348722,348728:348729,348731,348735,348743:348745,348749,348751:348752,348759,348768,348773,348780:348781,348784:348791
(UID FLAGS) </pre>

Posted at Nginx Forum: 
http://forum.nginx.org/read.php?2,231439,231440#msg-231440

the entire command does not show up on the webpage, copy and paste the
snippet in an editor

Posted at Nginx Forum: 
http://forum.nginx.org/read.php?2,231439,231441#msg-231441

guys, any ideas?

Posted at Nginx Forum: 
http://forum.nginx.org/read.php?2,231439,231463#msg-231463

Hello!

On Sat, Oct 06, 2012 at 01:53:54AM -0400, iceman wrote:

> gdb) p p->upstream.connection->data
> 205         pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module);
>
> When the command below is sent using telnet, only 4 k of data is accepted,
> then nginx hangs until i hit enter on keyboard......after which the
> truncated command is sent to the upstream imap server.
>
> I am using nginx 0.78, is this a known issue?

I would recommend the following:

a) Test with something better than telnet.  While telnet is
generally usable for testing, it might have issues with testing
things buffer sizes as telnet usually have it's own buffers.
Moreover, usually telnet works in line-at-a-time mode, which means
it's telnet who is responsible for handling of the command until
you hit enter.

b) If you still see the issue, upgrade to at least latest stable
version of nginx, 1.2.4, before further testing.  There is no such
version "0.78", but as long as it starts with "0." it's really
old.


--
Maxim Dounin
http://nginx.com/support.html