[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 "rb_dictionary.h"
#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);
	}

	/* All data should be already destroyed */
	rb_dictionary_destroy(auth->data, NULL, NULL);
	auth->data = NULL;
}

/* 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;
	}

	/* TODO send back ident */
	rb_helper_write(authd_helper, "R %x %c :%s", auth->cid, reject, reason);

	unset_provider(auth, id);
	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);
	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(name, sizeof(name), "%d provider data", 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
46d17a88	45	#include "rb_dictionary.h"
2b0cc3d3 EM	46	#include "authd.h"
	47	#include "provider.h"
	48
	49	rb_dlink_list auth_providers;
	50
	51	/* Clients waiting */
	52	struct auth_client auth_clients[MAX_CLIENTS];
	53
	54	/* Load a provider */
	55	void load_provider(struct auth_provider *provider)
	56	{
	57	provider->init();
	58	rb_dlinkAdd(provider, &provider->node, &auth_providers);
	59	}
	60
	61	void unload_provider(struct auth_provider *provider)
	62	{
	63	provider->destroy();
	64	rb_dlinkDelete(&provider->node, &auth_providers);
	65	}
	66
	67	/* Initalise all providers */
	68	void init_providers(void)
	69	{
	70	load_provider(&rdns_provider);
	71	load_provider(&ident_provider);
	72	}
	73
	74	/* Terminate all providers */
	75	void destroy_providers(void)
	76	{
	77	rb_dlink_node *ptr;
	78	struct auth_provider *provider;
	79
	80	/* Cancel outstanding connections */
	81	for (size_t i = 0; i < MAX_CLIENTS; i++)
	82	{
	83	if(auth_clients[i].cid)
	84	{
f7b37c1d EM	85	/* TBD - is this the right thing? */
	86	reject_client(&auth_clients[i], 0,
	87	"Authentication system is down... try reconnecting in a few seconds");
2b0cc3d3 EM	88	}
	89	}
	90
	91	RB_DLINK_FOREACH(ptr, auth_providers.head)
	92	{
	93	provider = ptr->data;
	94
	95	if(provider->destroy)
	96	provider->destroy();
	97	}
	98	}
	99
	100	/* Cancel outstanding providers for a client */
	101	void cancel_providers(struct auth_client *auth)
	102	{
	103	rb_dlink_node *ptr;
	104	struct auth_provider *provider;
	105
	106	RB_DLINK_FOREACH(ptr, auth_providers.head)
	107	{
	108	provider = ptr->data;
	109
	110	if(provider->cancel && is_provider(auth, provider->id))
	111	/* Cancel if required */
	112	provider->cancel(auth);
	113	}
46d17a88 EM	114
	115	/* All data should be already destroyed */
	116	rb_dictionary_destroy(auth->data, NULL, NULL);
	117	auth->data = NULL;
2b0cc3d3 EM	118	}
	119
	120	/* Provider is done */
	121	void provider_done(struct auth_client *auth, provider_t id)
	122	{
	123	rb_dlink_node *ptr;
	124	struct auth_provider *provider;
	125
	126	unset_provider(auth, id);
	127
	128	if(!auth->providers)
	129	{
	130	/* No more providers, done */
	131	accept_client(auth, 0);
	132	return;
	133	}
	134
	135	RB_DLINK_FOREACH(ptr, auth_providers.head)
	136	{
	137	provider = ptr->data;
	138
	139	if(provider->completed && is_provider(auth, provider->id))
	140	/* Notify pending clients who asked for it */
	141	provider->completed(auth, id);
	142	}
	143	}
	144
f7b37c1d EM	145	/* Reject a client */
f7b37c1d EM	146	void reject_client(struct auth_client auth, provider_t id, const char reason)
2b0cc3d3 EM	147	{
	148	uint16_t cid = auth->cid;
	149	char reject;
	150
	151	switch(id)
	152	{
	153	case PROVIDER_RDNS:
	154	reject = 'D';
	155	break;
	156	case PROVIDER_IDENT:
	157	reject = 'I';
	158	break;
	159	case PROVIDER_BLACKLIST:
	160	reject = 'B';
	161	break;
	162	case PROVIDER_NULL:
	163	default:
	164	reject = 'N';
	165	break;
	166	}
	167
46d17a88	168	/* TODO send back ident */
2b0cc3d3 EM	169	rb_helper_write(authd_helper, "R %x %c :%s", auth->cid, reject, reason);
	170
	171	unset_provider(auth, id);
46d17a88 EM	172	cancel_providers(auth);
46d17a88 EM	173	memset(&auth_clients[cid], 0, sizeof(struct auth_client));
2b0cc3d3 EM	174	}
	175
	176	/* Accept a client, cancel outstanding providers if any */
	177	void accept_client(struct auth_client *auth, provider_t id)
	178	{
	179	uint16_t cid = auth->cid;
	180
	181	rb_helper_write(authd_helper, "A %x %s %s", auth->cid, auth->username, auth->hostname);
	182
	183	unset_provider(auth, id);
46d17a88	184	cancel_providers(auth);
2b0cc3d3 EM	185	memset(&auth_clients[cid], 0, sizeof(struct auth_client));
	186	}
	187
	188	/* Send a notice to a client */
	189	void notice_client(struct auth_client auth, const char notice)
	190	{
	191	rb_helper_write(authd_helper, "N %x :%s", auth->cid, notice);
	192	}
	193
	194	/* Begin authenticating user */
	195	static void start_auth(const char cid, const char l_ip, const char l_port, const char c_ip, const char *c_port)
	196	{
	197	struct auth_provider *provider;
	198	struct auth_client *auth;
	199	long lcid = strtol(cid, NULL, 16);
f7b37c1d	200	char name[20];
2b0cc3d3 EM	201	rb_dlink_node *ptr;
	202
	203	if(lcid >= MAX_CLIENTS)
	204	return;
	205
	206	auth = &auth_clients[lcid];
	207	if(auth->cid != 0)
	208	/* Shouldn't get here */
	209	return;
	210
	211	auth->cid = (uint16_t)lcid;
	212
	213	rb_strlcpy(auth->l_ip, l_ip, sizeof(auth->l_ip));
	214	auth->l_port = (uint16_t)atoi(l_port); /* should be safe */
	215
	216	rb_strlcpy(auth->c_ip, c_ip, sizeof(auth->c_ip));
	217	auth->c_port = (uint16_t)atoi(c_port);
	218
46d17a88	219	snprintf(name, sizeof(name), "%d provider data", auth->cid);
f7b37c1d EM	220	auth->data = rb_dictionary_create(name, rb_uint32cmp);
f7b37c1d EM	221
2b0cc3d3 EM	222	RB_DLINK_FOREACH(ptr, auth_providers.head)
	223	{
	224	provider = ptr->data;
	225
	226	/* Execute providers */
	227	if(!provider->start(auth))
	228	{
	229	/* Rejected immediately */
	230	cancel_providers(auth);
	231	return;
	232	}
	233	}
	234
	235	/* If no providers are running, accept the client */
	236	if(!auth->providers)
	237	accept_client(auth, 0);
	238	}
	239
	240	/* Callback for the initiation */
	241	void handle_new_connection(int parc, char *parv[])
	242	{
	243	if(parc < 7)
	244	return;
	245
	246	start_auth(parv[1], parv[2], parv[3], parv[4], parv[5]);
	247	}