[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.
 */

/* 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).
 *
 * Provider-specific data for each client can be kept in an index of the data
 * struct member (using the provider's ID).
 *
 * 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.
 *
 * Eventually, stuff like *:line handling will be moved here, but that means we
 * have to talk to bandb directly first.
 *
 * --Elizafox, 9 March 2016
 */

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

rb_dlink_list auth_providers;

/* Clients waiting */
rb_dictionary *auth_clients;

/* Load a provider */
void load_provider(struct auth_provider *provider)
{
	if(rb_dlink_list_length(&auth_providers) >= MAX_PROVIDERS)
	{
		warn_opers(L_CRIT, "Exceeded maximum level of authd providers (%d max)", MAX_PROVIDERS);
		return;
	}

	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)
{
	auth_clients = rb_dictionary_create("pending auth clients", rb_uint32cmp);
	load_provider(&rdns_provider);
	load_provider(&ident_provider);
}

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

	/* Cancel outstanding connections */
	RB_DICTIONARY_FOREACH(auth, &iter, auth_clients)
	{
		/* TBD - is this the right thing? */
		reject_client(auth, 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);
	}

	rb_dictionary_delete(auth_clients, RB_UINT_TO_POINTER(auth->cid));
	rb_free(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)
{
	char reject;

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

/* Accept a client, cancel outstanding providers if any */
void accept_client(struct auth_client *auth, provider_t id)
{
	uint32_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);
}

/* Send a notice to a client */
void notice_client(struct auth_client *auth, const char *fmt, ...)
{
	char buf[BUFSIZE];
	va_list args;

	va_start(args, fmt);
	vsnprintf(buf, sizeof(buf), fmt, args);
	va_end(args);

	rb_helper_write(authd_helper, "N %x :%s", auth->cid, buf);
}

/* Send a warning to the IRC daemon for logging, etc. */
void warn_opers(notice_level_t level, const char *fmt, ...)
{
	char buf[BUFSIZE];
	va_list args;

	va_start(args, fmt);
	vsnprintf(buf, sizeof(buf), fmt, args);
	va_end(args);

	rb_helper_write(authd_helper, "W %c :%s", level, buf);
}

/* 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 = rb_malloc(sizeof(struct auth_client));
	long lcid = strtol(cid, NULL, 16);
	rb_dlink_node *ptr;

	if(lcid >= UINT32_MAX)
		return;

	auth->cid = (uint32_t)lcid;

	rb_strlcpy(auth->l_ip, l_ip, sizeof(auth->l_ip));
	auth->l_port = (uint16_t)atoi(l_port);	/* should be safe */
	(void) rb_inet_pton_sock(l_ip, (struct sockaddr *)&auth->l_addr);

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

#ifdef RB_IPV6
	if(GET_SS_FAMILY(&auth->l_addr) == AF_INET6)
		((struct sockaddr_in6 *)&auth->l_addr)->sin6_port = htons(auth->l_port);
	else
#endif
		((struct sockaddr_in *)&auth->l_addr)->sin_port = htons(auth->l_port);

#ifdef RB_IPV6
	if(GET_SS_FAMILY(&auth->c_addr) == AF_INET6)
		((struct sockaddr_in6 *)&auth->c_addr)->sin6_port = htons(auth->c_port);
	else
#endif
		((struct sockaddr_in *)&auth->c_addr)->sin_port = htons(auth->c_port);

	rb_dictionary_add(auth_clients, RB_UINT_TO_POINTER(auth->cid), auth);

	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)
	{
		warn_opers(L_CRIT, "BUG: received too few params for new connection (7 expected, got %d)", parc);
		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
89d22b9a EM	21	/* The basic design here is to have "authentication providers" that do things
89d22b9a EM	22	* like query ident and blacklists and even open proxies.
2b0cc3d3	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	26	*
89d22b9a EM	27	* Providers can either return failure immediately, immediate acceptance, or do
89d22b9a EM	28	* work in the background (calling set_provider to signal this).
2b0cc3d3	29	*
3e875f62 EM	30	* Provider-specific data for each client can be kept in an index of the data
3e875f62 EM	31	* struct member (using the provider's ID).
2b0cc3d3 EM	32	*
	33	* All providers must implement at a minimum a perform_provider function. You
	34	* don't have to implement the others if you don't need them.
	35	*
	36	* Providers may kick clients off by rejecting them. Upon rejection, all
	37	* providers are cancelled. They can also unconditionally accept them.
	38	*
	39	* When a provider is done and is neutral on accepting/rejecting a client, it
	40	* should call provider_done. Do NOT call this if you have accepted or rejected
	41	* the client.
	42	*
89d22b9a EM	43	* Eventually, stuff like *:line handling will be moved here, but that means we
	44	* have to talk to bandb directly first.
	45	*
2b0cc3d3 EM	46	* --Elizafox, 9 March 2016
	47	*/
	48
46d17a88	49	#include "rb_dictionary.h"
2b0cc3d3 EM	50	#include "authd.h"
	51	#include "provider.h"
	52
	53	rb_dlink_list auth_providers;
	54
	55	/* Clients waiting */
aba29d5a	56	rb_dictionary *auth_clients;
2b0cc3d3 EM	57
	58	/* Load a provider */
	59	void load_provider(struct auth_provider *provider)
	60	{
3e875f62	61	if(rb_dlink_list_length(&auth_providers) >= MAX_PROVIDERS)
b2ede1aa EM	62	{
b2ede1aa EM	63	warn_opers(L_CRIT, "Exceeded maximum level of authd providers (%d max)", MAX_PROVIDERS);
3e875f62	64	return;
b2ede1aa	65	}
3e875f62	66
2b0cc3d3 EM	67	provider->init();
	68	rb_dlinkAdd(provider, &provider->node, &auth_providers);
	69	}
	70
	71	void unload_provider(struct auth_provider *provider)
	72	{
	73	provider->destroy();
	74	rb_dlinkDelete(&provider->node, &auth_providers);
	75	}
	76
	77	/* Initalise all providers */
	78	void init_providers(void)
	79	{
3e875f62	80	auth_clients = rb_dictionary_create("pending auth clients", rb_uint32cmp);
2b0cc3d3 EM	81	load_provider(&rdns_provider);
	82	load_provider(&ident_provider);
	83	}
	84
	85	/* Terminate all providers */
	86	void destroy_providers(void)
	87	{
	88	rb_dlink_node *ptr;
aba29d5a	89	rb_dictionary_iter iter;
3e875f62	90	struct auth_client *auth;
2b0cc3d3 EM	91	struct auth_provider *provider;
	92
	93	/* Cancel outstanding connections */
a52c7a8e	94	RB_DICTIONARY_FOREACH(auth, &iter, auth_clients)
2b0cc3d3	95	{
3e875f62 EM	96	/* TBD - is this the right thing? */
3e875f62 EM	97	reject_client(auth, 0, "Authentication system is down... try reconnecting in a few seconds");
2b0cc3d3 EM	98	}
	99
	100	RB_DLINK_FOREACH(ptr, auth_providers.head)
	101	{
	102	provider = ptr->data;
	103
	104	if(provider->destroy)
	105	provider->destroy();
	106	}
	107	}
	108
	109	/* Cancel outstanding providers for a client */
	110	void cancel_providers(struct auth_client *auth)
	111	{
	112	rb_dlink_node *ptr;
	113	struct auth_provider *provider;
	114
	115	RB_DLINK_FOREACH(ptr, auth_providers.head)
	116	{
	117	provider = ptr->data;
	118
	119	if(provider->cancel && is_provider(auth, provider->id))
	120	/* Cancel if required */
	121	provider->cancel(auth);
	122	}
46d17a88	123
3e875f62 EM	124	rb_dictionary_delete(auth_clients, RB_UINT_TO_POINTER(auth->cid));
3e875f62 EM	125	rb_free(auth);
2b0cc3d3 EM	126	}
	127
	128	/* Provider is done */
	129	void provider_done(struct auth_client *auth, provider_t id)
	130	{
	131	rb_dlink_node *ptr;
	132	struct auth_provider *provider;
	133
	134	unset_provider(auth, id);
	135
	136	if(!auth->providers)
	137	{
	138	/* No more providers, done */
	139	accept_client(auth, 0);
	140	return;
	141	}
	142
	143	RB_DLINK_FOREACH(ptr, auth_providers.head)
	144	{
	145	provider = ptr->data;
	146
	147	if(provider->completed && is_provider(auth, provider->id))
	148	/* Notify pending clients who asked for it */
	149	provider->completed(auth, id);
	150	}
	151	}
	152
f7b37c1d EM	153	/* Reject a client */
f7b37c1d EM	154	void reject_client(struct auth_client auth, provider_t id, const char reason)
2b0cc3d3	155	{
2b0cc3d3 EM	156	char reject;
	157
	158	switch(id)
	159	{
	160	case PROVIDER_RDNS:
	161	reject = 'D';
	162	break;
	163	case PROVIDER_IDENT:
	164	reject = 'I';
	165	break;
	166	case PROVIDER_BLACKLIST:
	167	reject = 'B';
	168	break;
2b0cc3d3 EM	169	default:
	170	reject = 'N';
	171	break;
	172	}
	173
46d17a88	174	/* TODO send back ident */
2b0cc3d3 EM	175	rb_helper_write(authd_helper, "R %x %c :%s", auth->cid, reject, reason);
	176
	177	unset_provider(auth, id);
46d17a88	178	cancel_providers(auth);
2b0cc3d3 EM	179	}
	180
	181	/* Accept a client, cancel outstanding providers if any */
	182	void accept_client(struct auth_client *auth, provider_t id)
	183	{
3e875f62	184	uint32_t cid = auth->cid;
2b0cc3d3 EM	185
	186	rb_helper_write(authd_helper, "A %x %s %s", auth->cid, auth->username, auth->hostname);
	187
	188	unset_provider(auth, id);
46d17a88	189	cancel_providers(auth);
2b0cc3d3 EM	190	}
	191
	192	/* Send a notice to a client */
89d22b9a EM	193	void notice_client(struct auth_client auth, const char fmt, ...)
	194	{
	195	char buf[BUFSIZE];
	196	va_list args;
	197
	198	va_start(args, fmt);
	199	vsnprintf(buf, sizeof(buf), fmt, args);
	200	va_end(args);
	201
	202	rb_helper_write(authd_helper, "N %x :%s", auth->cid, buf);
	203	}
	204
	205	/* Send a warning to the IRC daemon for logging, etc. */
b2ede1aa	206	void warn_opers(notice_level_t level, const char *fmt, ...)
2b0cc3d3	207	{
89d22b9a EM	208	char buf[BUFSIZE];
	209	va_list args;
	210
	211	va_start(args, fmt);
	212	vsnprintf(buf, sizeof(buf), fmt, args);
	213	va_end(args);
	214
b2ede1aa	215	rb_helper_write(authd_helper, "W %c :%s", level, buf);
2b0cc3d3 EM	216	}
	217
	218	/* Begin authenticating user */
	219	static void start_auth(const char cid, const char l_ip, const char l_port, const char c_ip, const char *c_port)
	220	{
	221	struct auth_provider *provider;
3e875f62	222	struct auth_client *auth = rb_malloc(sizeof(struct auth_client));
2b0cc3d3 EM	223	long lcid = strtol(cid, NULL, 16);
	224	rb_dlink_node *ptr;
	225
3e875f62	226	if(lcid >= UINT32_MAX)
2b0cc3d3 EM	227	return;
2b0cc3d3 EM	228
3e875f62	229	auth->cid = (uint32_t)lcid;
2b0cc3d3 EM	230
	231	rb_strlcpy(auth->l_ip, l_ip, sizeof(auth->l_ip));
	232	auth->l_port = (uint16_t)atoi(l_port); /* should be safe */
32f8c78b	233	(void) rb_inet_pton_sock(l_ip, (struct sockaddr *)&auth->l_addr);
2b0cc3d3 EM	234
	235	rb_strlcpy(auth->c_ip, c_ip, sizeof(auth->c_ip));
	236	auth->c_port = (uint16_t)atoi(c_port);
32f8c78b	237	(void) rb_inet_pton_sock(c_ip, (struct sockaddr *)&auth->c_addr);
9c7498d5 EM	238
	239	#ifdef RB_IPV6
	240	if(GET_SS_FAMILY(&auth->l_addr) == AF_INET6)
32f8c78b	241	((struct sockaddr_in6 *)&auth->l_addr)->sin6_port = htons(auth->l_port);
9c7498d5 EM	242	else
9c7498d5 EM	243	#endif
32f8c78b	244	((struct sockaddr_in *)&auth->l_addr)->sin_port = htons(auth->l_port);
9c7498d5 EM	245
	246	#ifdef RB_IPV6
	247	if(GET_SS_FAMILY(&auth->c_addr) == AF_INET6)
32f8c78b	248	((struct sockaddr_in6 *)&auth->c_addr)->sin6_port = htons(auth->c_port);
9c7498d5 EM	249	else
9c7498d5 EM	250	#endif
32f8c78b	251	((struct sockaddr_in *)&auth->c_addr)->sin_port = htons(auth->c_port);
2b0cc3d3	252
3e875f62	253	rb_dictionary_add(auth_clients, RB_UINT_TO_POINTER(auth->cid), auth);
f7b37c1d	254
2b0cc3d3 EM	255	RB_DLINK_FOREACH(ptr, auth_providers.head)
	256	{
	257	provider = ptr->data;
	258
	259	/* Execute providers */
	260	if(!provider->start(auth))
	261	{
	262	/* Rejected immediately */
	263	cancel_providers(auth);
	264	return;
	265	}
	266	}
	267
	268	/* If no providers are running, accept the client */
	269	if(!auth->providers)
	270	accept_client(auth, 0);
	271	}
	272
	273	/* Callback for the initiation */
	274	void handle_new_connection(int parc, char *parv[])
	275	{
	276	if(parc < 7)
b2ede1aa EM	277	{
b2ede1aa EM	278	warn_opers(L_CRIT, "BUG: received too few params for new connection (7 expected, got %d)", parc);
2b0cc3d3	279	return;
b2ede1aa	280	}
2b0cc3d3 EM	281
	282	start_auth(parv[1], parv[2], parv[3], parv[4], parv[5]);
	283	}