1 /*
2  * Policy fetching for Secure Streams
3  *
4  * libwebsockets - small server side websockets and web server implementation
5  *
6  * Copyright (C) 2019 - 2020 Andy Green <andy@warmcat.com>
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to
10  * deal in the Software without restriction, including without limitation the
11  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
12  * sell copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
24  * IN THE SOFTWARE.
25  */
26 
27 #include <private-lib-core.h>
28 
29 typedef struct ss_fetch_policy {
30 	struct lws_ss_handle 	*ss;
31 	void			*opaque_data;
32 	/* ... application specific state ... */
33 
34 	lws_sorted_usec_list_t	sul;
35 
36 	uint8_t			partway;
37 } ss_fetch_policy_t;
38 
39 /* secure streams payload interface */
40 
41 static int
ss_fetch_policy_rx(void * userobj,const uint8_t * buf,size_t len,int flags)42 ss_fetch_policy_rx(void *userobj, const uint8_t *buf, size_t len, int flags)
43 {
44 	ss_fetch_policy_t *m = (ss_fetch_policy_t *)userobj;
45 	struct lws_context *context = (struct lws_context *)m->opaque_data;
46 
47 	if (flags & LWSSS_FLAG_SOM) {
48 		if (lws_ss_policy_parse_begin(context))
49 			return 1;
50 		m->partway = 1;
51 	}
52 
53 	if (len && lws_ss_policy_parse(context, buf, len) < 0)
54 		return 1;
55 
56 	if (flags & LWSSS_FLAG_EOM)
57 		m->partway = 2;
58 
59 	return 0;
60 }
61 
62 static int
ss_fetch_policy_tx(void * userobj,lws_ss_tx_ordinal_t ord,uint8_t * buf,size_t * len,int * flags)63 ss_fetch_policy_tx(void *userobj, lws_ss_tx_ordinal_t ord, uint8_t *buf,
64 		   size_t *len, int *flags)
65 {
66 	return 1;
67 }
68 
69 static void
policy_set(lws_sorted_usec_list_t * sul)70 policy_set(lws_sorted_usec_list_t *sul)
71 {
72 	ss_fetch_policy_t *m = lws_container_of(sul, ss_fetch_policy_t, sul);
73 	struct lws_context *context = (struct lws_context *)m->opaque_data;
74 
75 	/*
76 	 * We get called if the policy parse was successful, just after the
77 	 * ss connection close that was using the vhost from the old policy
78 	 */
79 
80 	if (lws_ss_policy_set(context, "updated"))
81 		lwsl_err("%s: policy set failed\n", __func__);
82 	else {
83 		context->policy_updated = 1;
84 		lws_state_transition_steps(&context->mgr_system,
85 					   LWS_SYSTATE_OPERATIONAL);
86 	}
87 }
88 
89 static int
ss_fetch_policy_state(void * userobj,void * sh,lws_ss_constate_t state,lws_ss_tx_ordinal_t ack)90 ss_fetch_policy_state(void *userobj, void *sh, lws_ss_constate_t state,
91 		      lws_ss_tx_ordinal_t ack)
92 {
93 	ss_fetch_policy_t *m = (ss_fetch_policy_t *)userobj;
94 	struct lws_context *context = (struct lws_context *)m->opaque_data;
95 
96 	lwsl_info("%s: %s, ord 0x%x\n", __func__, lws_ss_state_name(state),
97 		  (unsigned int)ack);
98 
99 	switch (state) {
100 	case LWSSSCS_CREATING:
101 		lws_ss_request_tx(m->ss);
102 		break;
103 	case LWSSSCS_CONNECTING:
104 		break;
105 
106 	case LWSSSCS_DISCONNECTED:
107 		lwsl_info("%s: DISCONNECTED\n", __func__);
108 		switch (m->partway) {
109 		case 1:
110 			lws_ss_policy_parse_abandon(context);
111 			break;
112 
113 		case 2:
114 			lws_sul_schedule(context, 0, &m->sul, policy_set, 1);
115 			break;
116 		}
117 		m->partway = 0;
118 		break;
119 
120 	default:
121 		break;
122 	}
123 
124 	return 0;
125 }
126 
127 int
lws_ss_sys_fetch_policy(struct lws_context * context)128 lws_ss_sys_fetch_policy(struct lws_context *context)
129 {
130 	lws_ss_info_t ssi;
131 
132 	if (context->hss_fetch_policy) /* already exists */
133 		return 0;
134 
135 	/* We're making an outgoing secure stream ourselves */
136 
137 	memset(&ssi, 0, sizeof(ssi));
138 	ssi.handle_offset	    = offsetof(ss_fetch_policy_t, ss);
139 	ssi.opaque_user_data_offset = offsetof(ss_fetch_policy_t, opaque_data);
140 	ssi.rx			    = ss_fetch_policy_rx;
141 	ssi.tx			    = ss_fetch_policy_tx;
142 	ssi.state		    = ss_fetch_policy_state;
143 	ssi.user_alloc		    = sizeof(ss_fetch_policy_t);
144 	ssi.streamtype		    = "fetch_policy";
145 
146 	if (lws_ss_create(context, 0, &ssi, context, &context->hss_fetch_policy,
147 			  NULL, NULL)) {
148 		/*
149 		 * If there's no fetch_policy streamtype, it can just be we're
150 		 * running on a proxied client with no policy of its own,
151 		 * it's OK.
152 		 */
153 		lwsl_info("%s: Create LWA auth ss failed (policy?)\n", __func__);
154 
155 		return 1;
156 	}
157 
158 	return 0;
159 }
160