[solanum.git] / authd / provider.c

/* authd/provider.c - authentication provider framework
 * Copyright (c) 2016 Elizabeth Myers <elizabeth@interlinked.me>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice is present in all copies.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON 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 ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/* So the basic design here is to have "authentication providers" that do
 * things like query ident and blacklists and even open proxies.
 *
 * Providers are registered statically in the struct auth_providers array. You will
 * probably want to add an item to the provider_t enum also.
 *
 * Providers can either return failure immediately, immediate acceptance, or
 * do work in the background (calling set_provider to signal this).
 *
 * It is up to providers to keep their own state on clients if they need to.
 *
 * All providers must implement at a minimum a perform_provider function. You
 * don't have to implement the others if you don't need them.
 *
 * Providers may kick clients off by rejecting them. Upon rejection, all
 * providers are cancelled. They can also unconditionally accept them.
 *
 * When a provider is done and is neutral on accepting/rejecting a client, it
 * should call provider_done. Do NOT call this if you have accepted or rejected
 * the client.
 *
 * --Elizafox, 9 March 2016
 */

#include "authd.h"
#include "provider.h"

rb_dlink_list auth_providers;

/* Clients waiting */
struct auth_client auth_clients[MAX_CLIENTS];

/* Load a provider */
void load_provider(struct auth_provider *provider)
{
	provider->init();
	rb_dlinkAdd(provider, &provider->node, &auth_providers);
}

void unload_provider(struct auth_provider *provider)
{
	provider->destroy();
	rb_dlinkDelete(&provider->node, &auth_providers);
}

/* Initalise all providers */
void init_providers(void)
{
	load_provider(&rdns_provider);
}

/* Terminate all providers */
void destroy_providers(void)
{
	rb_dlink_node *ptr;
	struct auth_provider *provider;

	/* Cancel outstanding connections */
	for (size_t i = 0; i < MAX_CLIENTS; i++)
	{
		if(auth_clients[i].cid)
		{
			/* TBD - is this the right thing?
			 * (NOTE - this error message is designed for morons) */
			reject_client(&auth_clients[i], 0,
					"IRC server reloading... try reconnecting in a few seconds");
		}
	}

	RB_DLINK_FOREACH(ptr, auth_providers.head)
	{
		provider = ptr->data;

		if(provider->destroy)
			provider->destroy();
	}
}

/* Cancel outstanding providers for a client */
void cancel_providers(struct auth_client *auth)
{
	rb_dlink_node *ptr;
	struct auth_provider *provider;

	RB_DLINK_FOREACH(ptr, auth_providers.head)
	{
		provider = ptr->data;

		if(provider->cancel && is_provider(auth, provider->id))
			/* Cancel if required */
			provider->cancel(auth);
	}
}

/* Provider is done */
void provider_done(struct auth_client *auth, provider_t id)
{
	rb_dlink_node *ptr;
	struct auth_provider *provider;

	unset_provider(auth, id);

	if(!auth->providers)
	{
		/* No more providers, done */
		accept_client(auth, 0);
		return;
	}

	RB_DLINK_FOREACH(ptr, auth_providers.head)
	{
		provider = ptr->data;

		if(provider->completed && is_provider(auth, provider->id))
			/* Notify pending clients who asked for it */
			provider->completed(auth, id);
	}
}

/* Reject a client, cancel outstanding providers if any */
void reject_client(struct auth_client *auth, provider_t id, const char *reason)
{
	uint16_t cid = auth->cid;

	rb_helper_write(authd_helper, "R %x :%s", auth->cid, reason);

	unset_provider(auth, id);

	if(auth->providers)
		cancel_providers(auth);

	memset(&auth_clients[cid], 0, sizeof(struct auth_client));
}

/* Accept a client, cancel outstanding providers if any */
void accept_client(struct auth_client *auth, provider_t id)
{
	uint16_t cid = auth->cid;

	rb_helper_write(authd_helper, "A %x %s %s", auth->cid, auth->username, auth->hostname);

	unset_provider(auth, id);

	if(auth->providers)
		cancel_providers(auth);

	memset(&auth_clients[cid], 0, sizeof(struct auth_client));
}

/* Send a notice to a client */
void notice_client(struct auth_client *auth, const char *notice)
{
	rb_helper_write(authd_helper, "N %x :%s", auth->cid, notice);
}

/* Begin authenticating user */
static void start_auth(const char *cid, const char *l_ip, const char *l_port, const char *c_addr, const char *c_port)
{
	rb_dlink_node *ptr;
	struct auth_provider *provider;
	struct auth_client *auth;
	long lcid = strtol(cid, NULL, 16);

	if(lcid >= MAX_CLIENTS)
		return;

	auth = &auth_clients[lcid];
	if(auth->cid != 0)
		/* Shouldn't get here */
		return;

	auth->cid = (uint16_t)lcid;

	(void)rb_inet_pton_sock(l_ip, (struct sockaddr *)&auth->l_ip);
	auth->l_port = (uint16_t)atoi(l_port); /* Safe cast, port shouldn't exceed 16 bits  */

	(void)rb_inet_pton_sock(c_addr, (struct sockaddr *)&auth->c_addr);
	auth->c_port = (uint16_t)atoi(c_port);

	RB_DLINK_FOREACH(ptr, auth_providers.head)
	{
		provider = ptr->data;

		/* Execute providers */
		if(!provider->start(auth))
		{
			/* Rejected immediately */
			cancel_providers(auth);
			return;
		}
	}

	/* If no providers are running, accept the client */
	if(!auth->providers)
		accept_client(auth, 0);
}

/* Callback for the initiation */
void handle_new_connection(int parc, char *parv[])
{
	if(parc < 7)
		return;

	start_auth(parv[1], parv[2], parv[3], parv[4], parv[5]);
}
Commit	Line	Data
0f95a274	1	/* authd/provider.c - authentication provider framework
05e17ac2 EM	2	* Copyright (c) 2016 Elizabeth Myers <elizabeth@interlinked.me>
	3	*
	4	* Permission to use, copy, modify, and/or distribute this software for any
	5	* purpose with or without fee is hereby granted, provided that the above
	6	* copyright notice and this permission notice is present in all copies.
	7	*
	8	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	9	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	10	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	11	* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
	12	* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	13	* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
	14	* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	15	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	16	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
	17	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	18	* POSSIBILITY OF SUCH DAMAGE.
	19	*/
	20
	21	/* So the basic design here is to have "authentication providers" that do
	22	* things like query ident and blacklists and even open proxies.
	23	*
	24	* Providers are registered statically in the struct auth_providers array. You will
	25	* probably want to add an item to the provider_t enum also.
	26	*
	27	* Providers can either return failure immediately, immediate acceptance, or
	28	* do work in the background (calling set_provider to signal this).
	29	*
	30	* It is up to providers to keep their own state on clients if they need to.
	31	*
	32	* All providers must implement at a minimum a perform_provider function. You
	33	* don't have to implement the others if you don't need them.
	34	*
	35	* Providers may kick clients off by rejecting them. Upon rejection, all
	36	* providers are cancelled. They can also unconditionally accept them.
	37	*
f42aa1a9 EM	38	* When a provider is done and is neutral on accepting/rejecting a client, it
	39	* should call provider_done. Do NOT call this if you have accepted or rejected
	40	* the client.
05e17ac2 EM	41	*
	42	* --Elizafox, 9 March 2016
	43	*/
	44
	45	#include "authd.h"
0f95a274	46	#include "provider.h"
05e17ac2	47
99e53867	48	rb_dlink_list auth_providers;
05e17ac2 EM	49
	50	/* Clients waiting */
	51	struct auth_client auth_clients[MAX_CLIENTS];
	52
99e53867 EM	53	/* Load a provider */
	54	void load_provider(struct auth_provider *provider)
	55	{
	56	provider->init();
	57	rb_dlinkAdd(provider, &provider->node, &auth_providers);
	58	}
	59
	60	void unload_provider(struct auth_provider *provider)
	61	{
	62	provider->destroy();
	63	rb_dlinkDelete(&provider->node, &auth_providers);
	64	}
	65
05e17ac2 EM	66	/* Initalise all providers */
	67	void init_providers(void)
	68	{
18764319	69	load_provider(&rdns_provider);
05e17ac2 EM	70	}
	71
	72	/* Terminate all providers */
f42aa1a9	73	void destroy_providers(void)
05e17ac2	74	{
99e53867 EM	75	rb_dlink_node *ptr;
99e53867 EM	76	struct auth_provider *provider;
05e17ac2 EM	77
	78	/* Cancel outstanding connections */
	79	for (size_t i = 0; i < MAX_CLIENTS; i++)
	80	{
	81	if(auth_clients[i].cid)
	82	{
	83	/* TBD - is this the right thing?
	84	* (NOTE - this error message is designed for morons) */
f42aa1a9	85	reject_client(&auth_clients[i], 0,
05e17ac2 EM	86	"IRC server reloading... try reconnecting in a few seconds");
	87	}
	88	}
	89
99e53867	90	RB_DLINK_FOREACH(ptr, auth_providers.head)
05e17ac2	91	{
99e53867 EM	92	provider = ptr->data;
	93
	94	if(provider->destroy)
	95	provider->destroy();
05e17ac2 EM	96	}
	97	}
	98
	99	/* Cancel outstanding providers for a client */
	100	void cancel_providers(struct auth_client *auth)
	101	{
99e53867 EM	102	rb_dlink_node *ptr;
99e53867 EM	103	struct auth_provider *provider;
05e17ac2	104
99e53867	105	RB_DLINK_FOREACH(ptr, auth_providers.head)
05e17ac2	106	{
99e53867 EM	107	provider = ptr->data;
	108
	109	if(provider->cancel && is_provider(auth, provider->id))
05e17ac2	110	/* Cancel if required */
99e53867	111	provider->cancel(auth);
05e17ac2 EM	112	}
	113	}
	114
	115	/* Provider is done */
99e53867	116	void provider_done(struct auth_client *auth, provider_t id)
05e17ac2	117	{
99e53867 EM	118	rb_dlink_node *ptr;
99e53867 EM	119	struct auth_provider *provider;
05e17ac2	120
99e53867	121	unset_provider(auth, id);
05e17ac2 EM	122
	123	if(!auth->providers)
	124	{
	125	/* No more providers, done */
f42aa1a9	126	accept_client(auth, 0);
05e17ac2 EM	127	return;
	128	}
	129
99e53867	130	RB_DLINK_FOREACH(ptr, auth_providers.head)
05e17ac2	131	{
99e53867 EM	132	provider = ptr->data;
	133
	134	if(provider->completed && is_provider(auth, provider->id))
05e17ac2	135	/* Notify pending clients who asked for it */
99e53867	136	provider->completed(auth, id);
05e17ac2 EM	137	}
	138	}
	139
	140	/* Reject a client, cancel outstanding providers if any */
99e53867	141	void reject_client(struct auth_client auth, provider_t id, const char reason)
05e17ac2 EM	142	{
	143	uint16_t cid = auth->cid;
	144
	145	rb_helper_write(authd_helper, "R %x :%s", auth->cid, reason);
	146
99e53867	147	unset_provider(auth, id);
f42aa1a9	148
05e17ac2 EM	149	if(auth->providers)
	150	cancel_providers(auth);
	151
	152	memset(&auth_clients[cid], 0, sizeof(struct auth_client));
	153	}
	154
	155	/* Accept a client, cancel outstanding providers if any */
99e53867	156	void accept_client(struct auth_client *auth, provider_t id)
05e17ac2 EM	157	{
	158	uint16_t cid = auth->cid;
	159
	160	rb_helper_write(authd_helper, "A %x %s %s", auth->cid, auth->username, auth->hostname);
	161
99e53867	162	unset_provider(auth, id);
f42aa1a9	163
05e17ac2 EM	164	if(auth->providers)
	165	cancel_providers(auth);
	166
	167	memset(&auth_clients[cid], 0, sizeof(struct auth_client));
	168	}
	169
	170	/* Send a notice to a client */
	171	void notice_client(struct auth_client auth, const char notice)
	172	{
	173	rb_helper_write(authd_helper, "N %x :%s", auth->cid, notice);
	174	}
	175
	176	/* Begin authenticating user */
18764319	177	static void start_auth(const char cid, const char l_ip, const char l_port, const char c_addr, const char *c_port)
05e17ac2	178	{
99e53867 EM	179	rb_dlink_node *ptr;
99e53867 EM	180	struct auth_provider *provider;
05e17ac2 EM	181	struct auth_client *auth;
	182	long lcid = strtol(cid, NULL, 16);
	183
	184	if(lcid >= MAX_CLIENTS)
	185	return;
	186
	187	auth = &auth_clients[lcid];
	188	if(auth->cid != 0)
	189	/* Shouldn't get here */
	190	return;
	191
	192	auth->cid = (uint16_t)lcid;
	193
5bfc606f	194	(void)rb_inet_pton_sock(l_ip, (struct sockaddr *)&auth->l_ip);
05e17ac2 EM	195	auth->l_port = (uint16_t)atoi(l_port); /* Safe cast, port shouldn't exceed 16 bits */
05e17ac2 EM	196
18764319	197	(void)rb_inet_pton_sock(c_addr, (struct sockaddr *)&auth->c_addr);
05e17ac2 EM	198	auth->c_port = (uint16_t)atoi(c_port);
05e17ac2 EM	199
99e53867	200	RB_DLINK_FOREACH(ptr, auth_providers.head)
05e17ac2	201	{
99e53867 EM	202	provider = ptr->data;
99e53867 EM	203
05e17ac2	204	/* Execute providers */
99e53867	205	if(!provider->start(auth))
05e17ac2 EM	206	{
	207	/* Rejected immediately */
	208	cancel_providers(auth);
	209	return;
	210	}
	211	}
	212
	213	/* If no providers are running, accept the client */
	214	if(!auth->providers)
f42aa1a9	215	accept_client(auth, 0);
05e17ac2 EM	216	}
	217
	218	/* Callback for the initiation */
	219	void handle_new_connection(int parc, char *parv[])
	220	{
f169fc88	221	if(parc < 7)
05e17ac2 EM	222	return;
05e17ac2 EM	223
5bfc606f	224	start_auth(parv[1], parv[2], parv[3], parv[4], parv[5]);
05e17ac2	225	}