squid 3.1 ICAP problem

Hi,

Symptoms: Squid 3.1 fails to interoperate correctly with an ICAP server
and gives the error "ICAP protocol error." in the browser.

Config:
---snip---
icap_enable on
icap_service service_req reqmod_precache 0 icap://localhost:1344/reqmod
icap_class class_req service_req
icap_access class_req allow all
---snip---

Detail:
I'm writing an ICAP server from scratch and as far as I can see from
RFC3507 and errata, there is nothing wrong with this transaction shown
below in tcpdump -X format:

16:36:29.552198 IP localhost.50566 > localhost.1344: P 1:72(71) ack 1
win 513 <nop,nop,timestamp 62423291 62423291>
        0x0000: 4500 007b 341c 4000 4006 085f 7f00 0001 E..{4.@.@.._....
        0x0010: 7f00 0001 c586 0540 bd99 b4e2 bdca fa3d .......@.......=
        0x0020: 8018 0201 fe6f 0000 0101 080a 03b8 80fb .....o..........
        0x0030: 03b8 80fb 4f50 5449 4f4e 5320 6963 6170 ....OPTIONS.icap
        0x0040: 3a2f 2f6c 6f63 616c 686f 7374 3a31 3334 ://localhost:134
        0x0050: 342f 7265 716d 6f64 2049 4341 502f 312e 4/reqmod.ICAP/1.
        0x0060: 300d 0a48 6f73 743a 206c 6f63 616c 686f 0..Host:.localho
        0x0070: 7374 3a31 3334 340d 0a0d 0a st:1344....
16:36:29.552205 IP localhost.1344 > localhost.50566: . ack 72 win 512
<nop,nop,timestamp 62423291 62423291>
        0x0000: 4500 0034 7ac6 4000 4006 c1fb 7f00 0001 E..4z.@.@.......
        0x0010: 7f00 0001 0540 c586 bdca fa3d bd99 b529 .....@.....=...)
        0x0020: 8010 0200 77c1 0000 0101 080a 03b8 80fb ....w...........
        0x0030: 03b8 80fb ....
16:36:29.552442 IP localhost.1344 > localhost.50566: P 1:195(194) ack 72
win 512 <nop,nop,timestamp 62423291 62423291>
        0x0000: 4500 00f6 7ac7 4000 4006 c138 7f00 0001 E...z.@.@..8....
        0x0010: 7f00 0001 0540 c586 bdca fa3d bd99 b529 .....@.....=...)
        0x0020: 8018 0200 feea 0000 0101 080a 03b8 80fb ................
        0x0030: 03b8 80fb 3230 3020 4f4b 0d0a 4461 7465 ....200.OK..Date
        0x0040: 3a20 4672 692c 2032 3320 4170 7220 3230 :.Fri,.23.Apr.20
        0x0050: 3130 2031 363a 3336 3a32 3920 2b30 3130 10.16:36:29.+010
        0x0060: 300d 0a53 6572 7665 723a 2043 656e 736f 0..Server:.Censo
        0x0070: 724e 6574 2f35 2e30 0d0a 4d65 7468 6f64 rNet/5.0..Method
        0x0080: 733a 2052 4551 4d4f 440d 0a53 6572 7669 s:.REQMOD..Servi
        0x0090: 6365 3a20 4365 6e73 6f72 4e65 7420 4943 ce:.CensorNet.IC
        0x00a0: 4150 2052 4551 4d4f 440d 0a49 5354 6167 AP.REQMOD..ISTag
        0x00b0: 3a20 2230 220d 0a45 6e63 6170 7375 6c61 :."0"..Encapsula
        0x00c0: 7465 643a 206e 756c 6c2d 626f 6479 3d30 ted:.null-body=0
        0x00d0: 0d0a 4d61 782d 436f 6e6e 6563 7469 6f6e ..Max-Connection
        0x00e0: 733a 2031 3030 0d0a 416c 6c6f 773a 2032 s:.100..Allow:.2
        0x00f0: 3034 0d0a 0d0a 04....

What is my ICAP server doing wrong that squid is complaining about? I.e.
what is the cause of the protocol error?

Regards, Dan...

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Dan Searle
CensorNet Ltd - professional & affordable Web & E-mail filtering
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