On 1/17/21 3:08 PM, Moti Berger wrote: > What should the ICAP response look like? The vast majority off ICAP responses containing an HTTP POST message will look like ICAP header + HTTP header + HTTP body. Please see RFC 3507 and its errata for examples of and discussion about those three components. It should help avoid guessing and developing by examples (which usually leads to bugs, especially where ICAP is involved). > What I do is to reply like this: > > (dI./M..ICAP/1.0 200 OK > ISTag: "SjIzlRA4te41axxcDOoiSl6rBRg4ZK" > Date: Sun, 17 Jan 2021 19:34:12 GMT > Server: BaseICAP/1.0 Python/3.6.12 > Encapsulated: req-hdr=0, req-body=360 > > POST http://www.dst-server.com:22222/v1/test HTTP/1.1 > x-new-header: {"key": "value"} > user-agent: python-requests/2.25.1 > accept-encoding: gzip, deflate > accept: */* > content-length: 16 > content-type: application/json > host: www.dst-server.com:22222 <http://www.dst-server.com:22222> FYI: The above incomplete ICAP response promises an HTTP request body, both on the ICAP level (req-body) and on the HTTP level (content-length: 16). > As I said, I use 'Preview: 0' since I don't mind the body. The question > is whether declaring the body starts at X (req-body=X) is OK even though > I don't have a body to send? It is not OK not to send the body. Encapsulated:req-body does more than declaring where the encapsulated headers end. It also promises an embedded HTTP body after those headers. You must encapsulate the body if the HTTP message should have one. You cannot adapt the header of an HTTP message with a body without also sending the HTTP body (virgin or adapted). Preview is pretty much irrelevant in this context -- the ICAP protocol does not care how the ICAP service gets the HTTP body to include in the ICAP response. There are unofficial ICAP extensions that make it possible to tell the ICAP client to reuse the body it has buffered while adapting the header, but you should get the baseline case working before bothering with those extensions -- they are optimizations that are not applicable to some transactions. > I think having req-null=X is bad since it > probably tells squid that I decided the adapted request should have no > body, but that's only a guess. If you meant to say "null-body", then you guessed correctly -- null-body means the adapted HTTP message has no body. That is not what you want to say when adapting most HTTP POST messages. HTH, Alex. _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users
