Citrix Systems Network Router 9.2 Manuel D’Utilisation
Chapter 6 Advanced Expressions: Parsing HTTP, TCP, and UDP Data
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Expressions for Extracting Segments of URLs
You can extract URLs and portions of URLs, such as the host name, or a segment
of the URL path. For example, the following expression identifies HTTP requests
for image files by extracting image file suffixes from the URL:
of the URL path. For example, the following expression identifies HTTP requests
for image files by extracting image file suffixes from the URL:
http.req.url.suffix.eq("jpeg") || http.req.url.suffix.eq("gif")
Most expressions for URLs operate on text and are described in
. This section
discusses the GET operation. The GET operation extracts text when used with the
following prefixes:
following prefixes:
•
HTTP.REQ.URL.PATH
•
VPN.BASEURL.PATH
•
VPN.CLIENTLESS_BASEURL.PATH
Cache-Control header.
MAX_AGE
Returns the value of the Cache-Control header Max-
Age. If this header is absent or invalid, 0 is returned.
Age. If this header is absent or invalid, 0 is returned.
Following is an example:
http.req.cache_control.max_age.le(3)
Cache-Control header.
MAX_STALE
Returns the value of the Cache-Control header Max-
Stale. If this header is absent or invalid, 0 is returned.
Stale. If this header is absent or invalid, 0 is returned.
Following is an example:
http.req.cache_control.max_stale.le(3)
Cache-Control header.
MIN_FRESH
Returns the value of the Cache-Control header Min-
Fresh. If this header is absent or invalid, 0 is returned.
Fresh. If this header is absent or invalid, 0 is returned.
Following is an example:
http.req.cache_control.min_fresh.le(3)
Cache-Control header.S_
MAXAGE
Returns the value of the Cache-Control header S-
Maxage. If this header is absent or invalid, 0 is returned.
Maxage. If this header is absent or invalid, 0 is returned.
Following is an example:
http.req.cache_control.s_maxage.eq(2)
Operations That Evaluate Cache-Control Headers
HTTP Header Operation
Description