.\" Copyright (c) 2001-2002 Packet Design, LLC. .\" All rights reserved. .\" .\" Subject to the following obligations and disclaimer of warranty, .\" use and redistribution of this software, in source or object code .\" forms, with or without modifications are expressly permitted by .\" Packet Design; provided, however, that: .\" .\" (i) Any and all reproductions of the source or object code .\" must include the copyright notice above and the following .\" disclaimer of warranties; and .\" (ii) No rights are granted, in any manner or form, to use .\" Packet Design trademarks, including the mark "PACKET DESIGN" .\" on advertising, endorsements, or otherwise except as such .\" appears in the above copyright notice or in the software. .\" .\" THIS SOFTWARE IS BEING PROVIDED BY PACKET DESIGN "AS IS", AND .\" TO THE MAXIMUM EXTENT PERMITTED BY LAW, PACKET DESIGN MAKES NO .\" REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING .\" THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED .\" WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, .\" OR NON-INFRINGEMENT. PACKET DESIGN DOES NOT WARRANT, GUARANTEE, .\" OR MAKE ANY REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS .\" OF THE USE OF THIS SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, .\" RELIABILITY OR OTHERWISE. IN NO EVENT SHALL PACKET DESIGN BE .\" LIABLE FOR ANY DAMAGES RESULTING FROM OR ARISING OUT OF ANY USE .\" OF THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY DIRECT, .\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, PUNITIVE, OR CONSEQUENTIAL .\" DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, LOSS OF .\" USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY THEORY OF .\" LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF .\" THE USE OF THIS SOFTWARE, EVEN IF PACKET DESIGN IS ADVISED OF .\" THE POSSIBILITY OF SUCH DAMAGE. .\" .\" Author: Archie Cobbs .\" .\" $Id: http_servlet.3,v 1.1 2012/02/21 23:25:53 misho Exp $ .\" .Dd April 22, 2002 .Dt HTTP_SERVLET 3 .Os .Sh NAME .Nm http_servlet .Nd HTTP response generation API .Sh LIBRARY PDEL Library (libpdel, \-lpdel) .Sh SYNOPSIS .In sys/types.h .In stdio.h .In netinet/in.h .In openssl/ssl.h .In pdel/http/http_defs.h .In pdel/http/http_server.h .In pdel/http/http_servlet.h .Sh DESCRIPTION The .Nm http_servlet API provides an interface for user code to generate HTTP responses for the .Xr http_server 3 HTTP server. .Pp The PDEL library comes with these predefined servlets: .Pp .Bl -dash -compact -offset 3n .It HTTP basic authentication: .Xr http_servlet_basicauth 3 .It HTTP secure cookie authentication: .Xr http_servlet_cookieauth 3 .It HTTP redirect servlet: .Xr http_servlet_redirect 3 .It File servlet: .Xr http_servlet_file 3 .It .Xr tmpl 3 template servlet: .Xr http_servlet_tmpl 3 .It XML servlet: .Xr http_servlet_xml 3 .It XML-RPC servlet: .Xr http_servlet_xmlrpc 3 .El .Pp Servlets are registered by first constructing the servlet object and then invoking .Fn http_server_register_servlet . A servlet is represented by a .Li "struct http_servlet" : .Pp .Bd -literal -offset 3n typedef int http_servlet_run_t(struct http_servlet *servlet, struct http_request *req, struct http_response *resp); typedef void http_servlet_destroy_t(struct http_servlet *servlet); struct http_servlet { void *arg; /* servlet cookie */ struct http_servlet_hook *hook; /* server info */ http_servlet_run_t *run; /* execute method */ http_servlet_destroy_t *destroy; /* destructor */ }; .Ed .Pp The .Va arg fields is private to the servlet itself and is ignored by the server. .Pp The .Va hook is an .Xr http_server 3 private pointer that should be initialized to .Dv NULL when the servlet is constructed. This pointer is set to a non- .Dv NULL value when the servlet is registered with a server. The servlet itself should not dereference or modify this field. .Pp .Fn run executes the servlet for a single request/response pair. Each response is handled by the server in a separate thread, and several request/response pairs may exist at the same time for the same servlet object; i.e., servlets are multi-threaded. Synchronization is the responsibility of the servlet. The thread executing the servlet may be canceled at any cancellation point, e.g., if the requesting user-agent closes the connection before the response has been sent. This means that the servlet code may need to register thread cleanup hooks to avoid leaking memory or other resources. .Pp .Fn destroy will be called when the servlet is being unregistered and destroyed (servlets can be registered only once; unregistering a servlet destroys it). It should free any resources allocated when the servlet was constructed. The .Xr http_server 3 code guarantees that when .Fn destroy is invoked, there will be no instances of the .Fn run method currently executing. .Sh RETURN VALUES If successful, .Fn run should return 1 to indicate that the response is complete, or 0 to indicate that the servlet did not generate a response and execution should continue with the next-best matching servlet. Zero return values are used by servlets that only generate a response conditionally, e.g., authorization servlets. .Pp On failure .Fn run should -1 and set .Va errno . In this case (typically due to a system error), if a response has not yet been sent, a generic "500 Internal Server Error" response will be automatically generated with the error string from .Xr strerror 3 . .Sh SEE ALSO .Xr http_client 3 , .Xr http_request 3 , .Xr http_response 3 , .Xr http_server 3 , .Xr http_servlet_basicauth 3 , .Xr http_servlet_cookieauth 3 , .Xr http_servlet_file 3 , .Xr http_servlet_redirect 3 , .Xr http_servlet_tmpl 3 , .Xr http_servlet_xml 3 , .Xr http_servlet_xmlrpc 3 , .Xr libpdel 3 .Rs .%A R. Fielding .%A J. Gettys .%A J. Mogul .%A H. Frystyk .%A L. Masinter .%A P. Leach .%A T. Berners-Lee .%T "Hypertext Transfer Protocol -- HTTP/1.1" .%O RFC 2616 .Re .Sh HISTORY The PDEL library was developed at Packet Design, LLC. .Dv "http://www.packetdesign.com/" .Sh AUTHORS .An Archie Cobbs Aq archie@freebsd.org