1 /*
2  * libwebsockets - small server side websockets and web server implementation
3  *
4  * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to
8  * deal in the Software without restriction, including without limitation the
9  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10  * sell copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22  * IN THE SOFTWARE.
23  */
24 
25 /*
26  * Information about how this protocol handles multiple use of connections.
27  *
28  * .flags of 0 indicates each connection must start with a fresh transport.
29  *
30  * Flags can be used to indicate the protocol itself supports different
31  * kinds of multiple use.  However the actual use or not of these may depend on
32  * negotiation with the remote peer.
33  *
34  * LWS_AP_FLAG_PIPELINE_TRANSACTIONS:	other instances can be queued on one
35  *					with an existing connection and get a
36  *					chance to "hot take over" the existing
37  *					transport in turn, like h1 keepalive
38  *					pipelining
39  *
40  * LWS_AP_FLAG_MUXABLE_STREAM:	an existing connection can absorb more child
41  *				connections and mux them as separate child
42  *				streams ongoing, like h2
43  */
44 
45 enum {
46 	LWS_AP_FLAG_PIPELINE_TRANSACTIONS			= (1 << 0),
47 	LWS_AP_FLAG_MUXABLE_STREAM				= (1 << 1),
48 };
49 
50 typedef struct lws_abs_protocol {
51 	const char	*name;
52 	int		alloc;
53 	int		flags;
54 
55 	int		(*create)(const struct lws_abs *ai);
56 	void		(*destroy)(lws_abs_protocol_inst_t **d);
57 	int		(*compare)(lws_abs_t *abs1, lws_abs_t *abs2);
58 
59 	/* events the transport invokes (handled by abstract protocol) */
60 
61 	int		(*accept)(lws_abs_protocol_inst_t *d);
62 	int		(*rx)(lws_abs_protocol_inst_t *d, const uint8_t *b, size_t l);
63 	int		(*writeable)(lws_abs_protocol_inst_t *d, size_t budget);
64 	int		(*closed)(lws_abs_protocol_inst_t *d);
65 	int		(*heartbeat)(lws_abs_protocol_inst_t *d);
66 
67 	/* as parent, we get a notification a new child / queue entry
68 	 * bound to us... this is the parent lws_abs_t as arg */
69 	int		(*child_bind)(lws_abs_t *abs);
70 } lws_abs_protocol_t;
71 
72 /**
73  * lws_abs_protocol_get_by_name() - returns a pointer to the named protocol ops
74  *
75  * \param name: the name of the abstract protocol
76  *
77  * Returns a pointer to the named protocol ops struct if available, otherwise
78  * NULL.
79  */
80 LWS_VISIBLE LWS_EXTERN const lws_abs_protocol_t *
81 lws_abs_protocol_get_by_name(const char *name);
82 
83 /*
84  * bring in public api pieces from protocols
85  */
86 
87 #include <libwebsockets/abstract/protocols/smtp.h>
88 
89