Redo of the authd-framework branch.

This is basically most of the code from the authd-framework branch, but
written to the new DNS code in master. Not quite done yet but getting
there.

authd/Makefile.am

@@ -2,6 +2,13 @@ pkglibexec_PROGRAMS = authd
 AM_CFLAGS=$(WARNFLAGS)
 AM_CPPFLAGS = -I../include -I../librb/include 
 
+authd_SOURCES =	\
+	authd.c	\
+	res.c \
+	reslib.c \
+	dns.c \
+	provider.c \
+	providers/rdns.c \
+	providers/ident.c
 
-authd_SOURCES = authd.c res.c reslib.c dns.c
 authd_LDADD = ../librb/src/librb.la

authd/dns.c

@@ -69,9 +69,10 @@ lookup_ip(const char *host, int aftype, DNSCB callback, void *data)
 
 /* See lookup_ip's comment */
 struct dns_query *
-lookup_hostname(const char *ip, int aftype, DNSCB callback, void *data)
+lookup_hostname(const char *ip, DNSCB callback, void *data)
 {
 	struct dns_query *query = rb_malloc(sizeof(struct dns_query));
+	int aftype;
 
 	if(!rb_inet_pton_sock(ip, (struct sockaddr *)&query->addr))
 	{
@@ -79,6 +80,8 @@ lookup_hostname(const char *ip, int aftype, DNSCB callback, void *data)
 		return NULL;
 	}
 
+	aftype = GET_SS_FAMILY(&query->addr);
+
 	if(aftype == AF_INET)
 		query->type = QUERY_PTR_A;
 #ifdef RB_IPV6
@@ -121,10 +124,10 @@ handle_lookup_ip_reply(void *data, struct DNSReply *reply)
 	if(!query)
 		/* Shouldn't happen */
 		exit(2);
-	
+
 	type = query->type;
 
-	if(!reply)
+	if(reply == NULL)
 		goto end;
 
 	switch(query->type)
@@ -165,13 +168,13 @@ handle_lookup_hostname_reply(void *data, struct DNSReply *reply)
 	char *hostname = NULL;
 	query_type type = QUERY_INVALID;
 
-	if(!query)
+	if(query == NULL)
 		/* Shouldn't happen */
 		exit(4);
 
 	type = query->type;
 
-	if(!reply)
+	if(reply == NULL)
 		goto end;
 
 	if(query->type == QUERY_PTR_A)
@@ -180,7 +183,7 @@ handle_lookup_hostname_reply(void *data, struct DNSReply *reply)
 		ip = (struct sockaddr_in *) &query->addr;
 		ip_fwd = (struct sockaddr_in *) &reply->addr;
 
-		if(ip->sin_addr.s_addr == ip_fwd->sin_addr.s_addr && strlen(reply->h_name) < 63)
+		if(ip->sin_addr.s_addr == ip_fwd->sin_addr.s_addr)
 			hostname = reply->h_name;
 	}
 #ifdef RB_IPV6
@@ -190,7 +193,7 @@ handle_lookup_hostname_reply(void *data, struct DNSReply *reply)
 		ip = (struct sockaddr_in6 *) &query->addr;
 		ip_fwd = (struct sockaddr_in6 *) &reply->addr;
 
-		if(memcmp(&ip->sin6_addr, &ip_fwd->sin6_addr, sizeof(struct in6_addr)) == 0 && strlen(reply->h_name) < 63)
+		if(memcmp(&ip->sin6_addr, &ip_fwd->sin6_addr, sizeof(struct in6_addr)) == 0)
 			hostname = reply->h_name;
 	}
 #endif
@@ -212,7 +215,7 @@ submit_dns_answer(const char *reply, bool status, query_type type, void *data)
 	if(!id || type == QUERY_INVALID)
 		exit(6);
 
-	if(!reply || !status)
+	if(reply == NULL || status == false)
 	{
 		rb_helper_write(authd_helper, "E %s E %c *", id, type);
 		rb_free(id);
@@ -243,10 +246,9 @@ resolve_dns(int parc, char *parv[])
 		break;
 #ifdef RB_IPV6
 	case 'S':
-		aftype = AF_INET6;
 #endif
 	case 'R':
-		if(!lookup_hostname(record, aftype, submit_dns_answer, id))
+		if(!lookup_hostname(record, submit_dns_answer, id))
 			submit_dns_answer(NULL, false, qtype, NULL);
 		break;
 	default:
@@ -257,7 +259,7 @@ resolve_dns(int parc, char *parv[])
 void
 enumerate_nameservers(const char *rid, const char letter)
 {
-	char buf[40 * IRCD_MAXNS]; /* Plenty */
+	char buf[(HOSTIPLEN + 1) * IRCD_MAXNS];
 	char *c = buf;
 	int i;
 
@@ -270,8 +272,7 @@ enumerate_nameservers(const char *rid, const char letter)
 
 	for(i = 0; i < irc_nscount; i++)
 	{
-		char addr[40];
+		char addr[HOSTIPLEN];
-		int ret;
 
 		rb_inet_ntop_sock((struct sockaddr *)&irc_nsaddr_list[i], addr, sizeof(addr));
 
@@ -282,8 +283,8 @@ enumerate_nameservers(const char *rid, const char letter)
 			return;
 		}
 
-		ret = snprintf(c, 40, "%s ", addr);
+		(void)snprintf(c, HOSTIPLEN + 1, "%s ", addr);
-		c += (size_t)ret;
+		c += strlen(addr) + 1;
 	}
 
 	*(--c) = '\0';

authd/dns.h

@@ -50,7 +50,7 @@ struct dns_query
 	void *data;
 };
 
-extern struct dns_query *lookup_hostname(const char *ip, int aftype, DNSCB callback, void *data);
+extern struct dns_query *lookup_hostname(const char *ip, DNSCB callback, void *data);
 extern struct dns_query *lookup_ip(const char *host, int aftype, DNSCB callback, void *data);
 extern void cancel_query(struct dns_query *query);
 

authd/provider.c

@@ -0,0 +1,245 @@
+/* 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);
+	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?
+			 * (NOTE - this error message is designed for morons) */
+			reject_client(&auth_clients[i], 0, true,
+					"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 if hard set to true */
+void reject_client(struct auth_client *auth, provider_t id, bool hard, 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(hard && 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);
+	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);
+
+	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]);
+}

authd/provider.h

@@ -0,0 +1,114 @@
+/* authd/provider.h - 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.
+ */
+
+#ifndef __CHARYBDIS_AUTHD_PROVIDER_H__
+#define __CHARYBDIS_AUTHD_PROVIDER_H__
+
+#include "stdinc.h"
+
+/* Arbitrary limit */
+#define MAX_CLIENTS 4096
+
+/* Registered providers */
+typedef enum
+{
+	PROVIDER_NULL = 0x0, /* Dummy value */
+	PROVIDER_RDNS = 0x1,
+	PROVIDER_IDENT = 0x2,
+	PROVIDER_BLACKLIST = 0x4,
+} provider_t;
+
+struct auth_client
+{
+	uint16_t cid;				/* Client ID */
+
+	char l_ip[HOSTIPLEN + 1];		/* Listener IP address */
+	uint16_t l_port;			/* Listener port */
+
+	char c_ip[HOSTIPLEN + 1];		/* Client IP address */
+	uint16_t c_port;			/* Client port */
+
+	char hostname[HOSTLEN + 1];		/* Used for DNS lookup */
+	char username[USERLEN + 1];		/* Used for ident lookup */
+
+	unsigned int providers;			/* Providers at work,
+						 * none left when set to 0 */
+};
+
+typedef bool (*provider_init_t)(void);
+typedef bool (*provider_perform_t)(struct auth_client *);
+typedef void (*provider_complete_t)(struct auth_client *, provider_t provider);
+typedef void (*provider_cancel_t)(struct auth_client *);
+typedef void (*provider_destroy_t)(void);
+
+struct auth_provider
+{
+	rb_dlink_node node;
+
+	provider_t id;
+
+	provider_init_t init;		/* Initalise the provider */
+	provider_destroy_t destroy;	/* Terminate the provider */
+
+	provider_perform_t start;	/* Perform authentication */
+	provider_cancel_t cancel;	/* Authentication cancelled */
+	provider_complete_t completed;	/* Callback for when other performers complete (think dependency chains) */
+};
+
+extern rb_dlink_list auth_providers;
+extern struct auth_provider rdns_provider;
+extern struct auth_provider ident_provider;
+
+extern struct auth_client auth_clients[MAX_CLIENTS];
+
+void load_provider(struct auth_provider *provider);
+void unload_provider(struct auth_provider *provider);
+
+void init_providers(void);
+void destroy_providers(void);
+void cancel_providers(struct auth_client *auth);
+
+void provider_done(struct auth_client *auth, provider_t id);
+void accept_client(struct auth_client *auth, provider_t id);
+void reject_client(struct auth_client *auth, provider_t id, bool hard, const char *reason);
+
+void notice_client(struct auth_client *auth, const char *notice);
+
+void handle_new_connection(int parc, char *parv[]);
+
+/* Provider is operating on this auth_client (set this if you have async work to do) */
+static inline void set_provider(struct auth_client *auth, provider_t provider)
+{
+	auth->providers |= provider;
+}
+
+/* Provider is no longer operating on this auth client (you should use provider_done) */
+static inline void unset_provider(struct auth_client *auth, provider_t provider)
+{
+	auth->providers &= ~provider;
+}
+
+/* Check if provider is operating on this auth client */
+static inline bool is_provider(struct auth_client *auth, provider_t provider)
+{
+	return auth->providers & provider;
+}
+
+#endif /* __CHARYBDIS_AUTHD_PROVIDER_H__ */

authd/providers/ident.c

@@ -0,0 +1,392 @@
+/* authd/providers/ident.c - ident lookup provider for authd
+ * 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.
+ */
+
+#include "stdinc.h"
+#include "match.h"
+#include "authd.h"
+#include "provider.h"
+#include "res.h"
+
+#define IDENT_BUFSIZE 128
+
+struct ident_query
+{
+	rb_dlink_node node;
+
+	struct auth_client *auth;		/* Our client */
+	time_t timeout;				/* Timeout interval */
+	rb_fde_t *F;				/* Our FD */
+};
+
+/* Goinked from old s_auth.c --Elizafox */
+static const char *messages[] =
+{
+	":*** Checking Ident",
+	":*** Got Ident response",
+	":*** No Ident response",
+};
+
+typedef enum
+{
+	REPORT_LOOKUP,
+	REPORT_FOUND,
+	REPORT_FAIL,
+} ident_message;
+
+static EVH timeout_ident_queries_event;
+static CNCB ident_connected;
+static PF read_ident_reply;
+
+static void client_fail(struct ident_query *query, ident_message message);
+static void client_success(struct ident_query *query);
+static void cleanup_query(struct ident_query *query);
+static char * get_valid_ident(char *buf);
+
+static rb_dlink_list queries;
+static struct ev_entry *timeout_ev;
+static int ident_timeout = 5;
+
+
+bool ident_init(void)
+{
+	timeout_ev = rb_event_addish("timeout_ident_queries_event", timeout_ident_queries_event, NULL, 1);
+	return (timeout_ev != NULL);
+}
+
+void ident_destroy(void)
+{
+	rb_dlink_node *ptr, *nptr;
+
+	/* Nuke all ident queries */
+	RB_DLINK_FOREACH_SAFE(ptr, nptr, queries.head)
+	{
+		struct ident_query *query = ptr->data;
+
+		notice_client(query->auth, messages[REPORT_FAIL]);
+
+		rb_close(query->F);
+		rb_free(query);
+		rb_dlinkDelete(ptr, &queries);
+	}
+}
+
+bool ident_start(struct auth_client *auth)
+{
+	struct ident_query *query = rb_malloc(sizeof(struct ident_query));
+	struct rb_sockaddr_storage l_addr, c_addr;
+	int family;
+	rb_fde_t *F;
+
+	query->auth = auth;
+	query->timeout = rb_current_time() + ident_timeout;
+
+	if((F = rb_socket(family, SOCK_STREAM, 0, "ident")) == NULL)
+	{
+		client_fail(query, REPORT_FAIL);
+		return true;	/* Not a fatal error */
+	}
+
+	query->F = F;
+
+	/* Build sockaddr_storages for rb_connect_tcp below */
+	if(!rb_inet_ntop_sock((struct sockaddr *)&l_addr, auth->l_ip, sizeof(l_addr)) ||
+		!rb_inet_ntop_sock((struct sockaddr *)&c_addr, auth->c_ip, sizeof(c_addr)))
+	{
+		client_fail(query, REPORT_FAIL);
+		return true;
+	}
+
+	/* Set the ports correctly */
+#ifdef RB_IPV6
+	if(GET_SS_FAMILY(&l_addr) == AF_INET6)
+		((struct sockaddr_in6 *)&l_addr)->sin6_port = 0;
+	else
+#endif
+		((struct sockaddr_in *)&l_addr)->sin_port = 0;
+
+#ifdef RB_IPV6
+	if(GET_SS_FAMILY(&c_addr) == AF_INET6)
+		((struct sockaddr_in6 *)&c_addr)->sin6_port = htons(113);
+	else
+#endif
+		((struct sockaddr_in *)&c_addr)->sin_port = htons(113);
+
+	rb_connect_tcp(F, (struct sockaddr *)&c_addr,
+			(struct sockaddr *)&l_addr,
+			GET_SS_LEN(&l_addr), ident_connected,
+			query, ident_timeout);
+
+	rb_dlinkAdd(query, &query->node, &queries);
+
+	set_provider(auth, PROVIDER_IDENT);
+	notice_client(auth, messages[REPORT_LOOKUP]);
+
+	return true;
+}
+
+void ident_cancel(struct auth_client *auth)
+{
+	rb_dlink_node *ptr, *nptr;
+
+	RB_DLINK_FOREACH_SAFE(ptr, nptr, queries.head)
+	{
+		struct ident_query *query = ptr->data;
+
+		if(query->auth == auth)
+		{
+			client_fail(query, REPORT_FAIL);
+
+			rb_close(query->F);
+			rb_free(query);
+			rb_dlinkDelete(ptr, &queries);
+
+			return;
+		}
+	}
+}
+
+/* Timeout outstanding queries */
+static void timeout_ident_queries_event(void *notused)
+{
+	rb_dlink_node *ptr, *nptr;
+
+	RB_DLINK_FOREACH_SAFE(ptr, nptr, queries.head)
+	{
+		struct ident_query *query = ptr->data;
+
+		if(query->timeout < rb_current_time())
+		{
+			client_fail(query, REPORT_FAIL);
+
+			rb_close(query->F);
+			rb_free(query);
+			rb_dlinkDelete(ptr, &queries);
+		}
+	}
+}
+
+/*
+ * ident_connected() - deal with the result of rb_connect_tcp()
+ *
+ * If the connection failed, we simply close the auth fd and report
+ * a failure. If the connection suceeded send the ident server a query
+ * giving "theirport , ourport". The write is only attempted *once* so
+ * it is deemed to be a fail if the entire write doesn't write all the
+ * data given.  This shouldnt be a problem since the socket should have
+ * a write buffer far greater than this message to store it in should
+ * problems arise. -avalon
+ */
+static void ident_connected(rb_fde_t *F, int error, void *data)
+{
+	struct ident_query *query = data;
+	struct auth_client *auth = query->auth;
+	char authbuf[32];
+	int authlen;
+
+	/* Check the error */
+	if(error != RB_OK)
+	{
+		/* We had an error during connection :( */
+		client_fail(query, REPORT_FAIL);
+		cleanup_query(query);
+		return;
+	}
+
+	snprintf(authbuf, sizeof(authbuf), "%u , %u\r\n",
+			auth->c_port, auth->l_port);
+	authlen = strlen(authbuf);
+
+	if(rb_write(query->F, authbuf, authlen) != authlen)
+	{
+		client_fail(query, REPORT_FAIL);
+		return;
+	}
+
+	read_ident_reply(query->F, query);
+}
+
+static void
+read_ident_reply(rb_fde_t *F, void *data)
+{
+	struct ident_query *query = data;
+	struct auth_client *auth = query->auth;
+	char *s = NULL;
+	char *t = NULL;
+	int len;
+	int count;
+	char buf[IDENT_BUFSIZE + 1];	/* buffer to read auth reply into */
+
+	len = rb_read(F, buf, IDENT_BUFSIZE);
+	if(len < 0 && rb_ignore_errno(errno))
+	{
+		rb_setselect(F, RB_SELECT_READ, read_ident_reply, query);
+		return;
+	}
+
+	if(len > 0)
+	{
+		buf[len] = '\0';
+
+		if((s = get_valid_ident(buf)))
+		{
+			t = auth->username;
+
+			while (*s == '~' || *s == '^')
+				s++;
+
+			for (count = USERLEN; *s && count; s++)
+			{
+				if(*s == '@')
+				{
+					break;
+				}
+				if(*s != ' ' && *s != ':' && *s != '[')
+				{
+					*t++ = *s;
+					count--;
+				}
+			}
+			*t = '\0';
+		}
+	}
+
+	if(s == NULL)
+		client_fail(query, REPORT_FAIL);
+	else
+		client_success(query);
+
+	cleanup_query(query);
+}
+
+static void client_fail(struct ident_query *query, ident_message report)
+{
+	struct auth_client *auth = query->auth;
+
+	if(auth)
+	{
+		rb_strlcpy(auth->username, "*", sizeof(auth->username));
+		notice_client(auth, messages[report]);
+		provider_done(auth, PROVIDER_IDENT);
+	}
+}
+
+static void client_success(struct ident_query *query)
+{
+	struct auth_client *auth = query->auth;
+
+	if(auth)
+	{
+		notice_client(auth, messages[REPORT_FOUND]);
+		provider_done(auth, PROVIDER_IDENT);
+	}
+}
+
+static void cleanup_query(struct ident_query *query)
+{
+	rb_dlink_node *ptr, *nptr;
+
+	RB_DLINK_FOREACH_SAFE(ptr, nptr, queries.head)
+	{
+		struct ident_query *query_l = ptr->data;
+
+		if(query_l == query)
+		{
+			rb_close(query->F);
+			rb_free(query);
+			rb_dlinkDelete(ptr, &queries);
+		}
+	}
+}
+
+/* get_valid_ident
+ * parse ident query reply from identd server
+ *
+ * Torn out of old s_auth.c because there was nothing wrong with it
+ * --Elizafox
+ *
+ * Inputs	- pointer to ident buf
+ * Outputs	- NULL if no valid ident found, otherwise pointer to name
+ * Side effects - None
+ */
+static char *
+get_valid_ident(char *buf)
+{
+	int remp = 0;
+	int locp = 0;
+	char *colon1Ptr;
+	char *colon2Ptr;
+	char *colon3Ptr;
+	char *commaPtr;
+	char *remotePortString;
+
+	/* All this to get rid of a sscanf() fun. */
+	remotePortString = buf;
+
+	colon1Ptr = strchr(remotePortString, ':');
+	if(!colon1Ptr)
+		return 0;
+
+	*colon1Ptr = '\0';
+	colon1Ptr++;
+	colon2Ptr = strchr(colon1Ptr, ':');
+	if(!colon2Ptr)
+		return 0;
+
+	*colon2Ptr = '\0';
+	colon2Ptr++;
+	commaPtr = strchr(remotePortString, ',');
+
+	if(!commaPtr)
+		return 0;
+
+	*commaPtr = '\0';
+	commaPtr++;
+
+	remp = atoi(remotePortString);
+	if(!remp)
+		return 0;
+
+	locp = atoi(commaPtr);
+	if(!locp)
+		return 0;
+
+	/* look for USERID bordered by first pair of colons */
+	if(!strstr(colon1Ptr, "USERID"))
+		return 0;
+
+	colon3Ptr = strchr(colon2Ptr, ':');
+	if(!colon3Ptr)
+		return 0;
+
+	*colon3Ptr = '\0';
+	colon3Ptr++;
+	return (colon3Ptr);
+}
+
+
+struct auth_provider ident_provider =
+{
+	.id = PROVIDER_IDENT,
+	.init = ident_init,
+	.destroy = ident_destroy,
+	.start = ident_start,
+	.cancel = ident_cancel,
+	.completed = NULL,
+};

authd/providers/rdns.c

@@ -0,0 +1,210 @@
+/* authd/providers/rdns.c - rDNS lookup provider for authd
+ * 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.
+ */
+
+#include "stdinc.h"
+#include "rb_commio.h"
+#include "authd.h"
+#include "provider.h"
+#include "res.h"
+#include "dns.h"
+
+struct user_query
+{
+	rb_dlink_node node;
+
+	struct auth_client *auth;		/* Our client */
+	struct dns_query *query;		/* Pending DNS query */
+	time_t timeout;				/* When the request times out */
+};
+
+/* Goinked from old s_auth.c --Elizabeth */
+static const char *messages[] =
+{
+	"*** Looking up your hostname...",
+	"*** Found your hostname",
+	"*** Couldn't look up your hostname",
+	"*** Your hostname is too long, ignoring hostname",
+};
+
+typedef enum
+{
+	REPORT_LOOKUP,
+	REPORT_FOUND,
+	REPORT_FAIL,
+	REPORT_TOOLONG,
+} dns_message;
+
+static void client_fail(struct user_query *query, dns_message message);
+static void client_success(struct user_query *query);
+static void get_dns_answer(const char *res, bool status, query_type type, void *data);
+
+static struct ev_entry *timeout_ev;
+static EVH timeout_dns_queries_event;
+static int rdns_timeout = 30;
+static rb_dlink_list queries;	/* Stored here for easy timeout */
+
+
+bool client_dns_init(void)
+{
+	timeout_ev = rb_event_addish("timeout_dns_queries_event", timeout_dns_queries_event, NULL, 5);
+	return (timeout_ev != NULL);
+}
+
+void client_dns_destroy(void)
+{
+	rb_dlink_node *ptr, *nptr;
+	struct user_query *query;
+
+	RB_DLINK_FOREACH_SAFE(ptr, nptr, queries.head)
+	{
+		client_fail(ptr->data, REPORT_FAIL);
+		rb_dlinkDelete(ptr, &queries);
+		rb_free(ptr);
+	}
+
+	rb_event_delete(timeout_ev);
+}
+
+bool client_dns_start(struct auth_client *auth)
+{
+	struct user_query *query = rb_malloc(sizeof(struct user_query));
+
+	query->auth = auth;
+	query->timeout = rb_current_time() + rdns_timeout;
+
+	query->query = lookup_hostname(auth->c_ip, get_dns_answer, query);
+
+	notice_client(auth, messages[REPORT_LOOKUP]);
+	set_provider(auth, PROVIDER_RDNS);
+	return true;
+}
+
+void client_dns_cancel(struct auth_client *auth)
+{
+	rb_dlink_node *ptr, *nptr;
+
+	RB_DLINK_FOREACH_SAFE(ptr, nptr, queries.head)
+	{
+		struct user_query *query = ptr->data;
+
+		if(query->auth == auth)
+		{
+			/* Victim found */
+			client_fail(query, REPORT_FAIL);
+			rb_dlinkDelete(ptr, &queries);
+			rb_free(query);
+			return;
+		}
+	}
+}
+
+static void
+get_dns_answer(const char *res, bool status, query_type type, void *data)
+{
+	struct user_query *query = data;
+	struct auth_client *auth = query->auth;
+	bool fail = false;
+	dns_message response;
+	rb_dlink_node *ptr, *nptr;
+
+	if(res == NULL || status == false)
+	{
+		response = REPORT_FAIL;
+		fail = true;
+		goto cleanup;
+	}
+	else if(strlen(res) > HOSTLEN)
+	{
+		/* Ah well. */
+		response = REPORT_TOOLONG;
+		fail = true;
+		goto cleanup;
+	}
+
+	rb_strlcpy(auth->hostname, res, HOSTLEN + 1);
+
+cleanup:
+	/* Clean us up off the pending queries list */
+	RB_DLINK_FOREACH_SAFE(ptr, nptr, queries.head)
+	{
+		struct user_query *query_l = ptr->data;
+
+		if(query == query_l)
+		{
+			/* Found */
+			if(fail)
+				client_fail(query, response);
+			else
+				client_success(query);
+
+			rb_dlinkDelete(ptr, &queries);
+			rb_free(query);
+			return;
+		}
+	}
+}
+
+/* Timeout outstanding queries */
+static void timeout_dns_queries_event(void *notused)
+{
+	rb_dlink_node *ptr, *nptr;
+
+	RB_DLINK_FOREACH_SAFE(ptr, nptr, queries.head)
+	{
+		struct user_query *query = ptr->data;
+
+		if(query->auth && query->timeout < rb_current_time())
+		{
+			client_fail(query, REPORT_FAIL);
+			rb_dlinkDelete(ptr, &queries);
+			rb_free(query);
+			return;
+		}
+	}
+}
+
+static void client_fail(struct user_query *query, dns_message report)
+{
+	struct auth_client *auth = query->auth;
+
+	rb_strlcpy(auth->hostname, "*", sizeof(auth->hostname));
+	notice_client(auth, messages[report]);
+	cancel_query(query->query);
+	provider_done(auth, PROVIDER_RDNS);
+}
+
+static void client_success(struct user_query *query)
+{
+	struct auth_client *auth = query->auth;
+
+	notice_client(auth, messages[REPORT_FOUND]);
+	cancel_query(query->query);
+	provider_done(auth, PROVIDER_RDNS);
+}
+
+struct auth_provider rdns_provider =
+{
+	.id = PROVIDER_RDNS,
+	.init = client_dns_init,
+	.destroy = client_dns_destroy,
+	.start = client_dns_start,
+	.cancel = client_dns_cancel,
+	.completed = NULL,
+};