[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 in the auth_providers linked list. It is planned to
 * use a bitmap to store provider ID's later.
 *
 * Providers can either return failure immediately, immediate acceptance, or
 * do work in the background (calling set_provider to signal this).
 *
 * A dictionary is provided in auth_client for storage of provider-specific data.
 *
 * 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);
	load_provider(&ident_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? */
			reject_client(&auth_clients[i], 0,
					"Authentication system is down... 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 */
void reject_client(struct auth_client *auth, provider_t id, const char *reason)
{
	uint16_t cid = auth->cid;
	char reject;

	switch(id)
	{
	case PROVIDER_RDNS:
		reject = 'D';
		break;
	case PROVIDER_IDENT:
		reject = 'I';
		break;
	case PROVIDER_BLACKLIST:
		reject = 'B';
		break;
	case PROVIDER_NULL:
	default:
		reject = 'N';
		break;
	}

	rb_helper_write(authd_helper, "R %x %c :%s", auth->cid, reject, 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_ip, const char *c_port)
{
	struct auth_provider *provider;
	struct auth_client *auth;
	long lcid = strtol(cid, NULL, 16);
	char name[20];
	rb_dlink_node *ptr;

	if(lcid >= MAX_CLIENTS)
		return;

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

	auth->cid = (uint16_t)lcid;

	rb_strlcpy(auth->l_ip, l_ip, sizeof(auth->l_ip));
	auth->l_port = (uint16_t)atoi(l_port);	/* should be safe */

	rb_strlcpy(auth->c_ip, c_ip, sizeof(auth->c_ip));
	auth->c_port = (uint16_t)atoi(c_port);

	snprintf("%d provider data", sizeof(name), auth->cid);
	auth->data = rb_dictionary_create(name, rb_uint32cmp);

	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
2b0cc3d3 EM	1	/* authd/provider.c - authentication provider framework
	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	*
f7b37c1d EM	24	* Providers are registered in the auth_providers linked list. It is planned to
f7b37c1d EM	25	* use a bitmap to store provider ID's later.
2b0cc3d3 EM	26	*
	27	* Providers can either return failure immediately, immediate acceptance, or
	28	* do work in the background (calling set_provider to signal this).
	29	*
f7b37c1d	30	* A dictionary is provided in auth_client for storage of provider-specific data.
2b0cc3d3 EM	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	*
	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.
	41	*
	42	* --Elizafox, 9 March 2016
	43	*/
	44
	45	#include "authd.h"
	46	#include "provider.h"
	47
	48	rb_dlink_list auth_providers;
	49
	50	/* Clients waiting */
	51	struct auth_client auth_clients[MAX_CLIENTS];
	52
	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
	66	/* Initalise all providers */
	67	void init_providers(void)
	68	{
	69	load_provider(&rdns_provider);
	70	load_provider(&ident_provider);
	71	}
	72
	73	/* Terminate all providers */
	74	void destroy_providers(void)
	75	{
	76	rb_dlink_node *ptr;
	77	struct auth_provider *provider;
	78
	79	/* Cancel outstanding connections */
	80	for (size_t i = 0; i < MAX_CLIENTS; i++)
	81	{
	82	if(auth_clients[i].cid)
	83	{
f7b37c1d EM	84	/* TBD - is this the right thing? */
	85	reject_client(&auth_clients[i], 0,
	86	"Authentication system is down... try reconnecting in a few seconds");
2b0cc3d3 EM	87	}
	88	}
	89
	90	RB_DLINK_FOREACH(ptr, auth_providers.head)
	91	{
	92	provider = ptr->data;
	93
	94	if(provider->destroy)
	95	provider->destroy();
	96	}
	97	}
	98
	99	/* Cancel outstanding providers for a client */
	100	void cancel_providers(struct auth_client *auth)
	101	{
	102	rb_dlink_node *ptr;
	103	struct auth_provider *provider;
	104
	105	RB_DLINK_FOREACH(ptr, auth_providers.head)
	106	{
	107	provider = ptr->data;
	108
	109	if(provider->cancel && is_provider(auth, provider->id))
	110	/* Cancel if required */
	111	provider->cancel(auth);
	112	}
	113	}
	114
	115	/* Provider is done */
	116	void provider_done(struct auth_client *auth, provider_t id)
	117	{
	118	rb_dlink_node *ptr;
	119	struct auth_provider *provider;
	120
	121	unset_provider(auth, id);
	122
	123	if(!auth->providers)
	124	{
	125	/* No more providers, done */
	126	accept_client(auth, 0);
	127	return;
	128	}
	129
	130	RB_DLINK_FOREACH(ptr, auth_providers.head)
	131	{
	132	provider = ptr->data;
	133
	134	if(provider->completed && is_provider(auth, provider->id))
	135	/* Notify pending clients who asked for it */
	136	provider->completed(auth, id);
	137	}
	138	}
	139
f7b37c1d EM	140	/* Reject a client */
f7b37c1d EM	141	void reject_client(struct auth_client auth, provider_t id, const char reason)
2b0cc3d3 EM	142	{
	143	uint16_t cid = auth->cid;
	144	char reject;
	145
	146	switch(id)
	147	{
	148	case PROVIDER_RDNS:
	149	reject = 'D';
	150	break;
	151	case PROVIDER_IDENT:
	152	reject = 'I';
	153	break;
	154	case PROVIDER_BLACKLIST:
	155	reject = 'B';
	156	break;
	157	case PROVIDER_NULL:
	158	default:
	159	reject = 'N';
	160	break;
	161	}
	162
	163	rb_helper_write(authd_helper, "R %x %c :%s", auth->cid, reject, reason);
	164
	165	unset_provider(auth, id);
	166
f7b37c1d	167	if(auth->providers)
2b0cc3d3 EM	168	{
	169	cancel_providers(auth);
	170	memset(&auth_clients[cid], 0, sizeof(struct auth_client));
	171	}
	172	}
	173
	174	/* Accept a client, cancel outstanding providers if any */
	175	void accept_client(struct auth_client *auth, provider_t id)
	176	{
	177	uint16_t cid = auth->cid;
	178
	179	rb_helper_write(authd_helper, "A %x %s %s", auth->cid, auth->username, auth->hostname);
	180
	181	unset_provider(auth, id);
	182
	183	if(auth->providers)
	184	cancel_providers(auth);
	185
	186	memset(&auth_clients[cid], 0, sizeof(struct auth_client));
	187	}
	188
	189	/* Send a notice to a client */
	190	void notice_client(struct auth_client auth, const char notice)
	191	{
	192	rb_helper_write(authd_helper, "N %x :%s", auth->cid, notice);
	193	}
	194
	195	/* Begin authenticating user */
	196	static void start_auth(const char cid, const char l_ip, const char l_port, const char c_ip, const char *c_port)
	197	{
	198	struct auth_provider *provider;
	199	struct auth_client *auth;
	200	long lcid = strtol(cid, NULL, 16);
f7b37c1d	201	char name[20];
2b0cc3d3 EM	202	rb_dlink_node *ptr;
	203
	204	if(lcid >= MAX_CLIENTS)
	205	return;
	206
	207	auth = &auth_clients[lcid];
	208	if(auth->cid != 0)
	209	/* Shouldn't get here */
	210	return;
	211
	212	auth->cid = (uint16_t)lcid;
	213
	214	rb_strlcpy(auth->l_ip, l_ip, sizeof(auth->l_ip));
	215	auth->l_port = (uint16_t)atoi(l_port); /* should be safe */
	216
	217	rb_strlcpy(auth->c_ip, c_ip, sizeof(auth->c_ip));
	218	auth->c_port = (uint16_t)atoi(c_port);
	219
f7b37c1d EM	220	snprintf("%d provider data", sizeof(name), auth->cid);
	221	auth->data = rb_dictionary_create(name, rb_uint32cmp);
	222
2b0cc3d3 EM	223	RB_DLINK_FOREACH(ptr, auth_providers.head)
	224	{
	225	provider = ptr->data;
	226
	227	/* Execute providers */
	228	if(!provider->start(auth))
	229	{
	230	/* Rejected immediately */
	231	cancel_providers(auth);
	232	return;
	233	}
	234	}
	235
	236	/* If no providers are running, accept the client */
	237	if(!auth->providers)
	238	accept_client(auth, 0);
	239	}
	240
	241	/* Callback for the initiation */
	242	void handle_new_connection(int parc, char *parv[])
	243	{
	244	if(parc < 7)
	245	return;
	246
	247	start_auth(parv[1], parv[2], parv[3], parv[4], parv[5]);
	248	}