pub const HOST: OptNumber;Expand description
Uri-Host, Uri-Port, Uri-Path, and Uri-Query
generated from RFC7252 section 5.10.1
The Uri-Host, Uri-Port, Uri-Path, and Uri-Query Options are used to specify the target resource of a request to a CoAP origin server. The options encode the different components of the request URI in a way that no percent-encoding is visible in the option values and that the full URI can be reconstructed at any involved endpoint. The syntax of CoAP URIs is defined in Section 6.
The steps for parsing URIs into options is defined in Section 6.4. These steps result in zero or more Uri-Host, Uri-Port, Uri-Path, and Uri-Query Options being included in a request, where each option holds the following values:
o the Uri-Host Option specifies the Internet host of the resource being requested,
o the Uri-Port Option specifies the transport-layer port number of the resource,
o each Uri-Path Option specifies one segment of the absolute path to the resource, and
o each Uri-Query Option specifies one argument parameterizing the resource.
Note: Fragments ([RFC3986], Section 3.5) are not part of the request URI and thus will not be transmitted in a CoAP request.
The default value of the Uri-Host Option is the IP literal representing the destination IP address of the request message. Likewise, the default value of the Uri-Port Option is the destination UDP port. The default values for the Uri-Host and Uri-Port Options are sufficient for requests to most servers. Explicit Uri-Host and Uri-Port Options are typically used when an endpoint hosts multiple virtual servers.
The Uri-Path and Uri-Query Option can contain any character sequence. No percent-encoding is performed. The value of a Uri-Path Option MUST NOT be “.” or “..” (as the request URI must be resolved before parsing it into options).
The steps for constructing the request URI from the options are defined in Section 6.5. Note that an implementation does not necessarily have to construct the URI; it can simply look up the target resource by examining the individual options.
Examples can be found in Appendix B.