curl_easy_setopt.3: document CLOSESOCKET* options

docs/libcurl/curl_easy_setopt.3

@@ -307,6 +307,17 @@ address blacklisting.  The default behavior is:
 Pass a pointer that will be untouched by libcurl and passed as the first
 argument in the opensocket callback set with \fICURLOPT_OPENSOCKETFUNCTION\fP.
 (Option added in 7.17.1.)
+.IP CURLOPT_CLOSESOCKETFUNCTION
+Function pointer that should match the \fIcurl_closesocket_callback\fP
+prototype found in \fI<curl/curl.h>\fP. This function gets called by libcurl
+instead of the \fIclose(2)\fP or \fIclosesocket(2)\fP call when sockets are
+closed (not for any other file descriptors). This is pretty much the reverse
+to the \fICURLOPT_OPENSOCKETFUNCTION\fP option. \fIReturn 0 to signal success
+and 1 if there was an error.  (Option added in 7.21.7)
+.IP CURLOPT_CLOSESOCKETDATA
+Pass a pointer that will be untouched by libcurl and passed as the first
+argument in the opensocket callback set with
+\fICURLOPT_CLOSESOCKETFUNCTION\fP.  (Option added in 7.21.7)
 .IP CURLOPT_PROGRESSFUNCTION
 Function pointer that should match the \fIcurl_progress_callback\fP prototype
 found in \fI<curl/curl.h>\fP. This function gets called by libcurl instead of