Adding upstream version 3.2.1+dfsg.upstream/3.2.1+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1042 insertions, 0 deletions

diff --git a/src/lib/packet.c b/src/lib/packet.c
new file mode 100644
index 0000000..acba8d9
--- /dev/null
+++ b/src/lib/packet.c
@@ -0,0 +1,1042 @@
+/*
+ * packet.c	Generic packet manipulation functions.
+ *
+ * Version:	$Id$
+ *
+ *   This library is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU Lesser General Public
+ *   License as published by the Free Software Foundation; either
+ *   version 2.1 of the License, or (at your option) any later version.
+ *
+ *   This library is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ *   Lesser General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Lesser General Public
+ *   License along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ *
+ * Copyright 2000-2006  The FreeRADIUS server project
+ */
+
+RCSID("$Id$")
+
+#include	<freeradius-devel/libradius.h>
+
+#ifdef WITH_UDPFROMTO
+#include	<freeradius-devel/udpfromto.h>
+#endif
+
+#include <fcntl.h>
+
+/*
+ *	See if two packets are identical.
+ *
+ *	Note that we do NOT compare the authentication vectors.
+ *	That's because if the authentication vector is different,
+ *	it means that the NAS has given up on the earlier request.
+ */
+int fr_packet_cmp(RADIUS_PACKET const *a, RADIUS_PACKET const *b)
+{
+	int rcode;
+
+	/*
+	 *	256-way fanout.
+	 */
+	if (a->id < b->id) return -1;
+	if (a->id > b->id) return +1;
+
+	if (a->sockfd < b->sockfd) return -1;
+	if (a->sockfd > b->sockfd) return +1;
+
+	/*
+	 *	Source ports are pretty much random.
+	 */
+	rcode = (int) a->src_port - (int) b->src_port;
+	if (rcode != 0) return rcode;
+
+	/*
+	 *	Usually many client IPs, and few server IPs
+	 */
+	rcode = fr_ipaddr_cmp(&a->src_ipaddr, &b->src_ipaddr);
+	if (rcode != 0) return rcode;
+
+	/*
+	 *	One socket can receive packets for multiple
+	 *	destination IPs, so we check that before checking the
+	 *	file descriptor.
+	 */
+	rcode = fr_ipaddr_cmp(&a->dst_ipaddr, &b->dst_ipaddr);
+	if (rcode != 0) return rcode;
+
+	/*
+	 *	At this point, the order of comparing socket FDs
+	 *	and/or destination ports doesn't matter.  One of those
+	 *	fields will make the socket unique, and the other is
+	 *	pretty much redundant.
+	 */
+	rcode = (int) a->dst_port - (int) b->dst_port;
+	return rcode;
+}
+
+int fr_inaddr_any(fr_ipaddr_t *ipaddr)
+{
+
+	if (ipaddr->af == AF_INET) {
+		if (ipaddr->ipaddr.ip4addr.s_addr == INADDR_ANY) {
+			return 1;
+		}
+
+#ifdef HAVE_STRUCT_SOCKADDR_IN6
+	} else if (ipaddr->af == AF_INET6) {
+		if (IN6_IS_ADDR_UNSPECIFIED(&(ipaddr->ipaddr.ip6addr))) {
+			return 1;
+		}
+#endif
+
+	} else {
+		fr_strerror_printf("Unknown address family");
+		return -1;
+	}
+
+	return 0;
+}
+
+
+/*
+ *	Create a fake "request" from a reply, for later lookup.
+ */
+void fr_request_from_reply(RADIUS_PACKET *request,
+			   RADIUS_PACKET const *reply)
+{
+	request->sockfd = reply->sockfd;
+	request->id = reply->id;
+#ifdef WITH_TCP
+	request->proto = reply->proto;
+#endif
+	request->src_port = reply->dst_port;
+	request->dst_port = reply->src_port;
+	request->src_ipaddr = reply->dst_ipaddr;
+	request->dst_ipaddr = reply->src_ipaddr;
+}
+
+/*
+ *	Open a socket on the given IP and port.
+ */
+int fr_socket(fr_ipaddr_t *ipaddr, uint16_t port)
+{
+	int sockfd;
+	struct sockaddr_storage salocal;
+	socklen_t	salen;
+
+	sockfd = socket(ipaddr->af, SOCK_DGRAM, 0);
+	if (sockfd < 0) {
+		fr_strerror_printf("cannot open socket: %s", fr_syserror(errno));
+		return sockfd;
+	}
+
+#ifdef WITH_UDPFROMTO
+	/*
+	 *	Initialize udpfromto for all sockets.
+	 */
+	if (udpfromto_init(sockfd) != 0) {
+		close(sockfd);
+		fr_strerror_printf("cannot initialize udpfromto: %s", fr_syserror(errno));
+		return -1;
+	}
+#endif
+
+	if (!fr_ipaddr2sockaddr(ipaddr, port, &salocal, &salen)) {
+		return sockfd;
+	}
+
+#ifdef HAVE_STRUCT_SOCKADDR_IN6
+	if (ipaddr->af == AF_INET6) {
+		/*
+		 *	Listening on '::' does NOT get you IPv4 to
+		 *	IPv6 mapping.  You've got to listen on an IPv4
+		 *	address, too.  This makes the rest of the server
+		 *	design a little simpler.
+		 */
+#ifdef IPV6_V6ONLY
+
+		if (IN6_IS_ADDR_UNSPECIFIED(&ipaddr->ipaddr.ip6addr)) {
+			int on = 1;
+
+			if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
+				       (char *)&on, sizeof(on)) < 0) {
+				close(sockfd);
+				fr_strerror_printf("Failed setting sockopt "
+						   "IPPROTO_IPV6 - IPV6_V6ONLY"
+						   ": %s", fr_syserror(errno));
+				return -1;
+			}
+		}
+#endif /* IPV6_V6ONLY */
+	}
+#endif /* HAVE_STRUCT_SOCKADDR_IN6 */
+
+#if (defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)) || defined(IP_DONTFRAG)
+	if (ipaddr->af == AF_INET) {
+		int flag;
+
+#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)
+
+		/*
+		 *	Disable PMTU discovery.  On Linux, this
+		 *	also makes sure that the "don't fragment"
+		 *	flag is zero.
+		 */
+		flag = IP_PMTUDISC_DONT;
+		if (setsockopt(sockfd, IPPROTO_IP, IP_MTU_DISCOVER,
+			       &flag, sizeof(flag)) < 0) {
+			close(sockfd);
+			fr_strerror_printf("Failed setting sockopt "
+					   "IPPROTO_IP - IP_MTU_DISCOVER: %s",
+					   fr_syserror(errno));
+			return -1;
+		}
+#endif
+
+#if defined(IP_DONTFRAG)
+		/*
+		 *	Ensure that the "don't fragment" flag is zero.
+		 */
+		flag = 0;
+		if (setsockopt(sockfd, IPPROTO_IP, IP_DONTFRAG,
+			   &flag, sizeof(flag)) < 0) {
+			close(sockfd);
+			fr_strerror_printf("Failed setting sockopt "
+					   "IPPROTO_IP - IP_DONTFRAG: %s",
+					   fr_syserror(errno));
+			return -1;
+		}
+#endif
+	}
+#endif
+
+	if (bind(sockfd, (struct sockaddr *) &salocal, salen) < 0) {
+		close(sockfd);
+		fr_strerror_printf("cannot bind socket: %s", fr_syserror(errno));
+		return -1;
+	}
+
+	return sockfd;
+}
+
+
+/*
+ *	We need to keep track of the socket & it's IP/port.
+ */
+typedef struct fr_packet_socket_t {
+	int		sockfd;
+	void		*ctx;
+
+	uint32_t	num_outgoing;
+
+	int		src_any;
+	fr_ipaddr_t	src_ipaddr;
+	uint16_t	src_port;
+
+	int		dst_any;
+	fr_ipaddr_t	dst_ipaddr;
+	uint16_t	dst_port;
+
+	bool		dont_use;
+
+#ifdef WITH_TCP
+	int		proto;
+#endif
+
+	uint8_t		id[32];
+} fr_packet_socket_t;
+
+
+#define FNV_MAGIC_PRIME (0x01000193)
+#define MAX_SOCKETS (1024)
+#define SOCKOFFSET_MASK (MAX_SOCKETS - 1)
+#define SOCK2OFFSET(sockfd) ((sockfd * FNV_MAGIC_PRIME) & SOCKOFFSET_MASK)
+
+/*
+ *	Structure defining a list of packets (incoming or outgoing)
+ *	that should be managed.
+ */
+struct fr_packet_list_t {
+	rbtree_t	*tree;
+
+	int		alloc_id;
+	uint32_t	num_outgoing;
+	int		last_recv;
+	int		num_sockets;
+
+	fr_packet_socket_t sockets[MAX_SOCKETS];
+};
+
+
+/*
+ *	Ugh.  Doing this on every sent/received packet is not nice.
+ */
+static fr_packet_socket_t *fr_socket_find(fr_packet_list_t *pl,
+					  int sockfd)
+{
+	int i, start;
+
+	i = start = SOCK2OFFSET(sockfd);
+
+	do {			/* make this hack slightly more efficient */
+		if (pl->sockets[i].sockfd == sockfd) return &pl->sockets[i];
+
+		i = (i + 1) & SOCKOFFSET_MASK;
+	} while (i != start);
+
+	return NULL;
+}
+
+bool fr_packet_list_socket_freeze(fr_packet_list_t *pl, int sockfd)
+{
+	fr_packet_socket_t *ps;
+
+	if (!pl) {
+		fr_strerror_printf("Invalid argument");
+		return false;
+	}
+
+	ps = fr_socket_find(pl, sockfd);
+	if (!ps) {
+		fr_strerror_printf("No such socket");
+		return false;
+	}
+
+	ps->dont_use = true;
+	return true;
+}
+
+bool fr_packet_list_socket_thaw(fr_packet_list_t *pl, int sockfd)
+{
+	fr_packet_socket_t *ps;
+
+	if (!pl) return false;
+
+	ps = fr_socket_find(pl, sockfd);
+	if (!ps) return false;
+
+	ps->dont_use = false;
+	return true;
+}
+
+
+bool fr_packet_list_socket_del(fr_packet_list_t *pl, int sockfd)
+{
+	fr_packet_socket_t *ps;
+
+	if (!pl) return false;
+
+	ps = fr_socket_find(pl, sockfd);
+	if (!ps) return false;
+
+	if (ps->num_outgoing != 0) {
+		fr_strerror_printf("socket is still in use");
+		return false;
+	}
+
+	ps->sockfd = -1;
+	pl->num_sockets--;
+
+	return true;
+}
+
+
+bool fr_packet_list_socket_add(fr_packet_list_t *pl, int sockfd, int proto,
+			      fr_ipaddr_t *dst_ipaddr, uint16_t dst_port,
+			      void *ctx)
+{
+	int i, start;
+	struct sockaddr_storage	src;
+	socklen_t		sizeof_src;
+	fr_packet_socket_t	*ps;
+
+	if (!pl || !dst_ipaddr || (dst_ipaddr->af == AF_UNSPEC)) {
+		fr_strerror_printf("Invalid argument");
+		return false;
+	}
+
+	if (pl->num_sockets >= MAX_SOCKETS) {
+		fr_strerror_printf("Too many open sockets");
+		return false;
+	}
+
+#ifndef WITH_TCP
+	if (proto != IPPROTO_UDP) {
+		fr_strerror_printf("only UDP is supported");
+		return false;
+	}
+#endif
+
+	ps = NULL;
+	i = start = SOCK2OFFSET(sockfd);
+
+	do {
+		if (pl->sockets[i].sockfd == -1) {
+			ps =  &pl->sockets[i];
+			break;
+		}
+
+		i = (i + 1) & SOCKOFFSET_MASK;
+	} while (i != start);
+
+	if (!ps) {
+		fr_strerror_printf("All socket entries are full");
+		return false;
+	}
+
+	memset(ps, 0, sizeof(*ps));
+	ps->ctx = ctx;
+#ifdef WITH_TCP
+	ps->proto = proto;
+#endif
+
+	/*
+	 *	Get address family, etc. first, so we know if we
+	 *	need to do udpfromto.
+	 *
+	 *	FIXME: udpfromto also does this, but it's not
+	 *	a critical problem.
+	 */
+	sizeof_src = sizeof(src);
+	memset(&src, 0, sizeof_src);
+	if (getsockname(sockfd, (struct sockaddr *) &src,
+			&sizeof_src) < 0) {
+		fr_strerror_printf("%s", fr_syserror(errno));
+		return false;
+	}
+
+	if (!fr_sockaddr2ipaddr(&src, sizeof_src, &ps->src_ipaddr,
+				&ps->src_port)) {
+		fr_strerror_printf("Failed to get IP");
+		return false;
+	}
+
+	ps->dst_ipaddr = *dst_ipaddr;
+	ps->dst_port = dst_port;
+
+	ps->src_any = fr_inaddr_any(&ps->src_ipaddr);
+	if (ps->src_any < 0) return false;
+
+	ps->dst_any = fr_inaddr_any(&ps->dst_ipaddr);
+	if (ps->dst_any < 0) return false;
+
+	/*
+	 *	As the last step before returning.
+	 */
+	ps->sockfd = sockfd;
+	pl->num_sockets++;
+
+	return true;
+}
+
+static int packet_entry_cmp(void const *one, void const *two)
+{
+	RADIUS_PACKET const * const *a = one;
+	RADIUS_PACKET const * const *b = two;
+
+	return fr_packet_cmp(*a, *b);
+}
+
+void fr_packet_list_free(fr_packet_list_t *pl)
+{
+	if (!pl) return;
+
+	rbtree_free(pl->tree);
+	free(pl);
+}
+
+
+/*
+ *	Caller is responsible for managing the packet entries.
+ */
+fr_packet_list_t *fr_packet_list_create(int alloc_id)
+{
+	int i;
+	fr_packet_list_t	*pl;
+
+	pl = malloc(sizeof(*pl));
+	if (!pl) return NULL;
+	memset(pl, 0, sizeof(*pl));
+
+	pl->tree = rbtree_create(NULL, packet_entry_cmp, NULL, 0);
+	if (!pl->tree) {
+		fr_packet_list_free(pl);
+		return NULL;
+	}
+
+	for (i = 0; i < MAX_SOCKETS; i++) {
+		pl->sockets[i].sockfd = -1;
+	}
+
+	pl->alloc_id = alloc_id;
+
+	return pl;
+}
+
+
+/*
+ *	If pl->alloc_id is set, then fr_packet_list_id_alloc() MUST
+ *	be called before inserting the packet into the list!
+ */
+bool fr_packet_list_insert(fr_packet_list_t *pl,
+			    RADIUS_PACKET **request_p)
+{
+	if (!pl || !request_p || !*request_p) return 0;
+
+	VERIFY_PACKET(*request_p);
+
+	return rbtree_insert(pl->tree, request_p);
+}
+
+RADIUS_PACKET **fr_packet_list_find(fr_packet_list_t *pl,
+				      RADIUS_PACKET *request)
+{
+	if (!pl || !request) return 0;
+
+	VERIFY_PACKET(request);
+
+	return rbtree_finddata(pl->tree, &request);
+}
+
+
+/*
+ *	This presumes that the reply has dst_ipaddr && dst_port set up
+ *	correctly (i.e. real IP, or "*").
+ */
+RADIUS_PACKET **fr_packet_list_find_byreply(fr_packet_list_t *pl,
+					      RADIUS_PACKET *reply)
+{
+	RADIUS_PACKET my_request, *request;
+	fr_packet_socket_t *ps;
+
+	if (!pl || !reply) return NULL;
+
+	VERIFY_PACKET(reply);
+
+	ps = fr_socket_find(pl, reply->sockfd);
+	if (!ps) return NULL;
+
+	/*
+	 *	Initialize request from reply, AND from the source
+	 *	IP & port of this socket.  The client may have bound
+	 *	the socket to 0, in which case it's some random port,
+	 *	that is NOT in the original request->src_port.
+	 */
+	my_request.sockfd = reply->sockfd;
+	my_request.id = reply->id;
+
+#ifdef WITH_TCP
+	/*
+	 *	TCP sockets are always bound to the correct src/dst IP/port
+	 */
+	if (ps->proto == IPPROTO_TCP) {
+		reply->dst_ipaddr = ps->src_ipaddr;
+		reply->dst_port = ps->src_port;
+		reply->src_ipaddr = ps->dst_ipaddr;
+		reply->src_port = ps->dst_port;
+
+		my_request.src_ipaddr = ps->src_ipaddr;
+		my_request.src_port = ps->src_port;
+		my_request.dst_ipaddr = ps->dst_ipaddr;
+		my_request.dst_port = ps->dst_port;
+
+	} else
+#endif
+	{
+		if (ps->src_any) {
+			my_request.src_ipaddr = ps->src_ipaddr;
+		} else {
+			my_request.src_ipaddr = reply->dst_ipaddr;
+		}
+		my_request.src_port = ps->src_port;
+
+		my_request.dst_ipaddr = reply->src_ipaddr;
+		my_request.dst_port = reply->src_port;
+	}
+
+#ifdef WITH_TCP
+	my_request.proto = reply->proto;
+#endif
+	request = &my_request;
+
+	return rbtree_finddata(pl->tree, &request);
+}
+
+
+bool fr_packet_list_yank(fr_packet_list_t *pl, RADIUS_PACKET *request)
+{
+	rbnode_t *node;
+
+	if (!pl || !request) return false;
+
+	VERIFY_PACKET(request);
+
+	node = rbtree_find(pl->tree, &request);
+	if (!node) return false;
+
+	rbtree_delete(pl->tree, node);
+	return true;
+}
+
+uint32_t fr_packet_list_num_elements(fr_packet_list_t *pl)
+{
+	if (!pl) return 0;
+
+	return rbtree_num_elements(pl->tree);
+}
+
+
+/*
+ *	1 == ID was allocated & assigned
+ *	0 == couldn't allocate ID.
+ *
+ *	Note that this ALSO assigns a socket to use, and updates
+ *	packet->request->src_ipaddr && packet->request->src_port
+ *
+ *	In multi-threaded systems, the calls to id_alloc && id_free
+ *	should be protected by a mutex.  This does NOT have to be
+ *	the same mutex as the one protecting the insert/find/yank
+ *	calls!
+ *
+ *	We assume that the packet has dst_ipaddr && dst_port
+ *	already initialized.  We will use those to find an
+ *	outgoing socket.  The request MAY also have src_ipaddr set.
+ *
+ *	We also assume that the sender doesn't care which protocol
+ *	should be used.
+ */
+bool fr_packet_list_id_alloc(fr_packet_list_t *pl, int proto,
+			    RADIUS_PACKET **request_p, void **pctx)
+{
+	int i, j, k, fd, id, start_i, start_j, start_k;
+	int src_any = 0;
+	fr_packet_socket_t *ps= NULL;
+	RADIUS_PACKET *request = *request_p;
+
+	VERIFY_PACKET(request);
+
+	if ((request->dst_ipaddr.af == AF_UNSPEC) ||
+	    (request->dst_port == 0)) {
+		fr_strerror_printf("No destination address/port specified");
+		return false;
+	}
+
+#ifndef WITH_TCP
+	if ((proto != 0) && (proto != IPPROTO_UDP)) {
+		fr_strerror_printf("Invalid destination protocol");
+		return false;
+	}
+#endif
+
+	/*
+	 *	Special case: unspec == "don't care"
+	 */
+	if (request->src_ipaddr.af == AF_UNSPEC) {
+		memset(&request->src_ipaddr, 0, sizeof(request->src_ipaddr));
+		request->src_ipaddr.af = request->dst_ipaddr.af;
+	}
+
+	src_any = fr_inaddr_any(&request->src_ipaddr);
+	if (src_any < 0) {
+		fr_strerror_printf("Can't check src_ipaddr");
+		return false;
+	}
+
+	/*
+	 *	MUST specify a destination address.
+	 */
+	if (fr_inaddr_any(&request->dst_ipaddr) != 0) {
+		fr_strerror_printf("Must specify a dst_ipaddr");
+		return false;
+	}
+
+	/*
+	 *	FIXME: Go to an LRU system.  This prevents ID re-use
+	 *	for as long as possible.  The main problem with that
+	 *	approach is that it requires us to populate the
+	 *	LRU/FIFO when we add a new socket, or a new destination,
+	 *	which can be expensive.
+	 *
+	 *	The LRU can be avoided if the caller takes care to free
+	 *	Id's only when all responses have been received, OR after
+	 *	a timeout.
+	 *
+	 *	Right now, the random approach is almost OK... it's
+	 *	brute-force over all of the available ID's, BUT using
+	 *	random numbers for everything spreads the load a bit.
+	 *
+	 *	The old method had a hash lookup on allocation AND
+	 *	on free.  The new method has brute-force on allocation,
+	 *	and near-zero cost on free.
+	 */
+
+	id = fd = -1;
+	start_i = fr_rand() & SOCKOFFSET_MASK;
+
+#define ID_i ((i + start_i) & SOCKOFFSET_MASK)
+	for (i = 0; i < MAX_SOCKETS; i++) {
+		if (pl->sockets[ID_i].sockfd == -1) continue; /* paranoia */
+
+		ps = &(pl->sockets[ID_i]);
+
+		/*
+		 *	This socket is marked as "don't use for new
+		 *	packets".  But we can still receive packets
+		 *	that are outstanding.
+		 */
+		if (ps->dont_use) continue;
+
+		/*
+		 *	All IDs are allocated: ignore it.
+		 */
+		if (ps->num_outgoing == 256) continue;
+
+#ifdef WITH_TCP
+		if (ps->proto != proto) continue;
+#endif
+
+		/*
+		 *	Address families don't match, skip it.
+		 */
+		if (ps->src_ipaddr.af != request->dst_ipaddr.af) continue;
+
+		/*
+		 *	MUST match dst port, if we have one.
+		 */
+		if ((ps->dst_port != 0) &&
+		    (ps->dst_port != request->dst_port)) continue;
+
+		/*
+		 *	MUST match requested src port, if one has been given.
+		 */
+		if ((request->src_port != 0) &&
+		    (ps->src_port != request->src_port)) continue;
+
+		/*
+		 *	We don't care about the source IP, but this
+		 *	socket is link local, and the requested
+		 *	destination is not link local.  Ignore it.
+		 */
+		if (src_any && (ps->src_ipaddr.af == AF_INET) &&
+		    (((ps->src_ipaddr.ipaddr.ip4addr.s_addr >> 24) & 0xff) == 127) &&
+		    (((request->dst_ipaddr.ipaddr.ip4addr.s_addr >> 24) & 0xff) != 127)) continue;
+
+		/*
+		 *	We're sourcing from *, and they asked for a
+		 *	specific source address: ignore it.
+		 */
+		if (ps->src_any && !src_any) continue;
+
+		/*
+		 *	We're sourcing from a specific IP, and they
+		 *	asked for a source IP that isn't us: ignore
+		 *	it.
+		 */
+		if (!ps->src_any && !src_any &&
+		    (fr_ipaddr_cmp(&request->src_ipaddr,
+				   &ps->src_ipaddr) != 0)) continue;
+
+		/*
+		 *	UDP sockets are allowed to match
+		 *	destination IPs exactly, OR a socket
+		 *	with destination * is allowed to match
+		 *	any requested destination.
+		 *
+		 *	TCP sockets must match the destination
+		 *	exactly.  They *always* have dst_any=0,
+		 *	so the first check always matches.
+		 */
+		if (!ps->dst_any &&
+		    (fr_ipaddr_cmp(&request->dst_ipaddr,
+				   &ps->dst_ipaddr) != 0)) continue;
+
+		/*
+		 *	Otherwise, this socket is OK to use.
+		 */
+
+		/*
+		 *	Look for a free Id, starting from a random number.
+		 */
+		start_j = fr_rand() & 0x1f;
+#define ID_j ((j + start_j) & 0x1f)
+		for (j = 0; j < 32; j++) {
+			if (ps->id[ID_j] == 0xff) continue;
+
+
+			start_k = fr_rand() & 0x07;
+#define ID_k ((k + start_k) & 0x07)
+			for (k = 0; k < 8; k++) {
+				if ((ps->id[ID_j] & (1 << ID_k)) != 0) continue;
+
+				ps->id[ID_j] |= (1 << ID_k);
+				id = (ID_j * 8) + ID_k;
+				fd = i;
+				break;
+			}
+			if (fd >= 0) break;
+		}
+#undef ID_i
+#undef ID_j
+#undef ID_k
+		if (fd >= 0) break;
+	}
+
+	/*
+	 *	Ask the caller to allocate a new ID.
+	 */
+	if (fd < 0) {
+		fr_strerror_printf("Failed finding socket, caller must allocate a new one");
+		return false;
+	}
+
+	/*
+	 *	Set the ID, source IP, and source port.
+	 */
+	request->id = id;
+
+	request->sockfd = ps->sockfd;
+	request->src_ipaddr = ps->src_ipaddr;
+	request->src_port = ps->src_port;
+
+	/*
+	 *	If we managed to insert it, we're done.
+	 */
+	if (fr_packet_list_insert(pl, request_p)) {
+		if (pctx) *pctx = ps->ctx;
+		ps->num_outgoing++;
+		pl->num_outgoing++;
+		return true;
+	}
+
+	/*
+	 *	Mark the ID as free.  This is the one line from
+	 *	id_free() that we care about here.
+	 */
+	ps->id[(request->id >> 3) & 0x1f] &= ~(1 << (request->id & 0x07));
+
+	request->id = -1;
+	request->sockfd = -1;
+	request->src_ipaddr.af = AF_UNSPEC;
+	request->src_port = 0;
+
+	return false;
+}
+
+/*
+ *	Should be called AFTER yanking it from the list, so that
+ *	any newly inserted entries don't collide with this one.
+ */
+bool fr_packet_list_id_free(fr_packet_list_t *pl,
+			    RADIUS_PACKET *request, bool yank)
+{
+	fr_packet_socket_t *ps;
+
+	if (!pl || !request) return false;
+
+	VERIFY_PACKET(request);
+
+	if (yank && !fr_packet_list_yank(pl, request)) return false;
+
+	ps = fr_socket_find(pl, request->sockfd);
+	if (!ps) return false;
+
+#if 0
+	if (!ps->id[(request->id >> 3) & 0x1f] & (1 << (request->id & 0x07))) {
+		fr_exit(1);
+	}
+#endif
+
+	ps->id[(request->id >> 3) & 0x1f] &= ~(1 << (request->id & 0x07));
+
+	ps->num_outgoing--;
+	pl->num_outgoing--;
+
+	request->id = -1;
+	request->src_ipaddr.af = AF_UNSPEC; /* id_alloc checks this */
+	request->src_port = 0;
+
+	return true;
+}
+
+/*
+ *	We always walk RBTREE_DELETE_ORDER, which is like RBTREE_IN_ORDER, except that
+ *	<0 means error, stop
+ *	0  means OK, continue
+ *	1  means delete current node and stop
+ *	2  means delete current node and continue
+ */
+int fr_packet_list_walk(fr_packet_list_t *pl, void *ctx, rb_walker_t callback)
+{
+	if (!pl || !callback) return 0;
+
+	return rbtree_walk(pl->tree, RBTREE_DELETE_ORDER, callback, ctx);
+}
+
+int fr_packet_list_fd_set(fr_packet_list_t *pl, fd_set *set)
+{
+	int i, maxfd;
+
+	if (!pl || !set) return 0;
+
+	maxfd = -1;
+
+	for (i = 0; i < MAX_SOCKETS; i++) {
+		if (pl->sockets[i].sockfd == -1) continue;
+		FD_SET(pl->sockets[i].sockfd, set);
+		if (pl->sockets[i].sockfd > maxfd) {
+			maxfd = pl->sockets[i].sockfd;
+		}
+	}
+
+	if (maxfd < 0) return -1;
+
+	return maxfd + 1;
+}
+
+/*
+ *	Round-robins the receivers, without priority.
+ *
+ *	FIXME: Add sockfd, if -1, do round-robin, else do sockfd
+ *		IF in fdset.
+ */
+RADIUS_PACKET *fr_packet_list_recv(fr_packet_list_t *pl, fd_set *set)
+{
+	int start;
+	RADIUS_PACKET *packet;
+
+	if (!pl || !set) return NULL;
+
+	start = pl->last_recv;
+	do {
+		start++;
+		start &= SOCKOFFSET_MASK;
+
+		if (pl->sockets[start].sockfd == -1) continue;
+
+		if (!FD_ISSET(pl->sockets[start].sockfd, set)) continue;
+
+#ifdef WITH_TCP
+		if (pl->sockets[start].proto == IPPROTO_TCP) {
+			packet = fr_tcp_recv(pl->sockets[start].sockfd, 0);
+			if (!packet) {
+				fr_strerror_printf("TCP connection has been closed");
+				return NULL;
+			}
+
+			/*
+			 *	We always know src/dst ip/port for TCP
+			 *	sockets.  So just fill them in.  Since
+			 *	we read the packet from the TCP
+			 *	socket, we invert src/dst.
+			 */
+			packet->dst_ipaddr = pl->sockets[start].src_ipaddr;
+			packet->dst_port = pl->sockets[start].src_port;
+			packet->src_ipaddr = pl->sockets[start].dst_ipaddr;
+			packet->src_port = pl->sockets[start].dst_port;
+
+		} else
+#endif
+
+		/*
+		 *	Rely on rad_recv() to fill in the required
+		 *	fields.
+		 */
+		packet = rad_recv(NULL, pl->sockets[start].sockfd, 0);
+		if (!packet) continue;
+
+		/*
+		 *	Call fr_packet_list_find_byreply().  If it
+		 *	doesn't find anything, discard the reply.
+		 */
+
+		pl->last_recv = start;
+#ifdef WITH_TCP
+		packet->proto = pl->sockets[start].proto;
+#endif
+		return packet;
+	} while (start != pl->last_recv);
+
+	return NULL;
+}
+
+uint32_t fr_packet_list_num_incoming(fr_packet_list_t *pl)
+{
+	uint32_t num_elements;
+
+	if (!pl) return 0;
+
+	num_elements = rbtree_num_elements(pl->tree);
+	if (num_elements < pl->num_outgoing) return 0; /* panic! */
+
+	return num_elements - pl->num_outgoing;
+}
+
+uint32_t fr_packet_list_num_outgoing(fr_packet_list_t *pl)
+{
+	if (!pl) return 0;
+
+	return pl->num_outgoing;
+}
+
+/*
+ *	Debug the packet if requested.
+ */
+void fr_packet_header_print(FILE *fp, RADIUS_PACKET *packet, bool received)
+{
+	char src_ipaddr[128];
+	char dst_ipaddr[128];
+
+	if (!fp) return;
+	if (!packet) return;
+
+	/*
+	 *	Client-specific debugging re-prints the input
+	 *	packet into the client log.
+	 *
+	 *	This really belongs in a utility library
+	 */
+	if (is_radius_code(packet->code)) {
+		fprintf(fp, "%s %s Id %i from %s%s%s:%i to %s%s%s:%i length %zu\n",
+		        received ? "Received" : "Sent",
+		        fr_packet_codes[packet->code],
+		        packet->id,
+		        packet->src_ipaddr.af == AF_INET6 ? "[" : "",
+		        inet_ntop(packet->src_ipaddr.af,
+				  &packet->src_ipaddr.ipaddr,
+				  src_ipaddr, sizeof(src_ipaddr)),
+			packet->src_ipaddr.af == AF_INET6 ? "]" : "",
+		        packet->src_port,
+		        packet->dst_ipaddr.af == AF_INET6 ? "[" : "",
+		        inet_ntop(packet->dst_ipaddr.af,
+				  &packet->dst_ipaddr.ipaddr,
+				  dst_ipaddr, sizeof(dst_ipaddr)),
+		        packet->dst_ipaddr.af == AF_INET6 ? "]" : "",
+		        packet->dst_port,
+		        packet->data_len);
+	} else {
+		fprintf(fp, "%s code %u Id %i from %s%s%s:%i to %s%s%s:%i length %zu\n",
+		        received ? "Received" : "Sent",
+		        packet->code,
+		        packet->id,
+		        packet->src_ipaddr.af == AF_INET6 ? "[" : "",
+		        inet_ntop(packet->src_ipaddr.af,
+				  &packet->src_ipaddr.ipaddr,
+				  src_ipaddr, sizeof(src_ipaddr)),
+		        packet->src_ipaddr.af == AF_INET6 ? "]" : "",
+		        packet->src_port,
+		        packet->dst_ipaddr.af == AF_INET6 ? "[" : "",
+		        inet_ntop(packet->dst_ipaddr.af,
+				  &packet->dst_ipaddr.ipaddr,
+				  dst_ipaddr, sizeof(dst_ipaddr)),
+		        packet->dst_ipaddr.af == AF_INET6 ? "]" : "",
+		        packet->dst_port,
+		        packet->data_len);
+	}
+}
+