initial cut at split out dhcrelay, whacked from usr.sbin/dhcp/ and sbin/dhclient

1 files changed, 496 insertions, 0 deletions

diff --git a/usr.sbin/dhcrelay/dispatch.c b/usr.sbin/dhcrelay/dispatch.c
new file mode 100644
index 00000000000..a38850842ad
--- /dev/null
+++ b/usr.sbin/dhcrelay/dispatch.c
@@ -0,0 +1,496 @@
+/*	$OpenBSD: dispatch.c,v 1.1 2004/04/12 21:10:28 henning Exp $	*/
+
+/*
+ * Copyright 2004 Henning Brauer <henning@openbsd.org>
+ * Copyright (c) 1995, 1996, 1997, 1998, 1999
+ * The Internet Software Consortium.   All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``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 INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS 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.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#include "dhcpd.h"
+
+#include <sys/ioctl.h>
+
+#include <net/if_media.h>
+#include <ifaddrs.h>
+#include <poll.h>
+
+struct protocol *protocols;
+struct timeout *timeouts;
+static struct timeout *free_timeouts;
+static int interfaces_invalidated;
+void (*bootp_packet_handler)(struct interface_info *,
+    struct dhcp_packet *, int, unsigned int,
+    struct iaddr, struct hardware *);
+
+static int interface_status(struct interface_info *ifinfo);
+
+/*
+ * Use getifaddrs() to get a list of all the attached interfaces.  For
+ * each interface that's of type INET and not the loopback interface,
+ * register that interface with the network I/O software, figure out
+ * what subnet it's on, and add it to the list of interfaces.
+ */
+void
+discover_interfaces(struct interface_info *iface)
+{
+	struct sockaddr_in foo;
+	struct ifaddrs *ifap, *ifa;
+	struct ifreq *tif;
+
+	if (getifaddrs(&ifap) != 0)
+		error("getifaddrs failed");
+
+	for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
+		if ((ifa->ifa_flags & IFF_LOOPBACK) ||
+		    (ifa->ifa_flags & IFF_POINTOPOINT) ||
+		    (!(ifa->ifa_flags & IFF_UP)))
+			continue;
+
+		if (strcmp(iface->name, ifa->ifa_name))
+			continue;
+
+		/*
+		 * If we have the capability, extract link information
+		 * and record it in a linked list.
+		 */
+		if (ifa->ifa_addr->sa_family == AF_LINK) {
+			struct sockaddr_dl *foo =
+			    (struct sockaddr_dl *)ifa->ifa_addr;
+			iface->index = foo->sdl_index;
+			iface->hw_address.hlen = foo->sdl_alen;
+			iface->hw_address.htype = HTYPE_ETHER; /* XXX */
+			memcpy(iface->hw_address.haddr,
+			    LLADDR(foo), foo->sdl_alen);
+		} else if (ifa->ifa_addr->sa_family == AF_INET) {
+			struct iaddr addr;
+
+			memcpy(&foo, ifa->ifa_addr, sizeof(foo));
+			if (foo.sin_addr.s_addr == htonl(INADDR_LOOPBACK))
+				continue;
+			if (!iface->ifp) {
+				int len = IFNAMSIZ + ifa->ifa_addr->sa_len;
+				if ((tif = malloc(len)) == NULL)
+					error("no space to remember ifp");
+				strlcpy(tif->ifr_name, ifa->ifa_name, IFNAMSIZ);
+				memcpy(&tif->ifr_addr, ifa->ifa_addr,
+				    ifa->ifa_addr->sa_len);
+				iface->ifp = tif;
+				iface->primary_address = foo.sin_addr;
+			}
+			addr.len = 4;
+			memcpy(addr.iabuf, &foo.sin_addr.s_addr, addr.len);
+		}
+	}
+
+	if (!iface->ifp)
+		error("%s: not found", iface->name);
+
+	/* Register the interface... */
+	if_register_receive(iface);
+	if_register_send(iface);
+	add_protocol(iface->name, iface->rfdesc, got_one, iface);
+
+	freeifaddrs(ifap);
+}
+
+void
+reinitialize_interfaces(void)
+{
+	interfaces_invalidated = 1;
+}
+
+/*
+ * Wait for packets to come in using poll().  When a packet comes in,
+ * call receive_packet to receive the packet and possibly strip hardware
+ * addressing information from it, and then call through the
+ * bootp_packet_handler hook to try to do something with it.
+ */
+void
+dispatch(void)
+{
+	int count, i, to_msec, nfds = 0;
+	struct protocol *l;
+	struct pollfd *fds;
+	time_t howlong;
+
+	nfds = 0;
+	for (l = protocols; l; l = l->next)
+		nfds++;
+
+	fds = malloc(nfds * sizeof(struct pollfd));
+	if (fds == NULL)
+		error("Can't allocate poll structures.");
+
+	do {
+		/*
+		 * Call any expired timeouts, and then if there's still
+		 * a timeout registered, time out the select call then.
+		 */
+another:
+		if (timeouts) {
+			struct timeout *t;
+			if (timeouts->when <= cur_time) {
+				t = timeouts;
+				timeouts = timeouts->next;
+				(*(t->func))(t->what);
+				t->next = free_timeouts;
+				free_timeouts = t;
+				goto another;
+			}
+
+			/*
+			 * Figure timeout in milliseconds, and check for
+			 * potential overflow, so we can cram into an
+			 * int for poll, while not polling with a
+			 * negative timeout and blocking indefinetely.
+			 */
+			howlong = timeouts->when - cur_time;
+			if (howlong > INT_MAX / 1000)
+				howlong = INT_MAX / 1000;
+			to_msec = howlong * 1000;
+		} else
+			to_msec = -1;
+
+		/* Set up the descriptors to be polled. */
+		i = 0;
+
+		for (l = protocols; l; l = l->next) {
+			struct interface_info *ip = l->local;
+			if (ip && (l->handler != got_one || !ip->dead)) {
+				fds[i].fd = l->fd;
+				fds[i].events = POLLIN;
+				fds[i].revents = 0;
+				i++;
+			}
+		}
+
+		if (i == 0)
+			error("No live interfaces to poll on - exiting.");
+
+		/* Wait for a packet or a timeout... XXX */
+		count = poll(fds, nfds, to_msec);
+
+		/* Not likely to be transitory... */
+		if (count == -1) {
+			if (errno == EAGAIN || errno == EINTR) {
+				time(&cur_time);
+				continue;
+			}
+			else
+				error("poll: %m");
+		}
+
+		/* Get the current time... */
+		time(&cur_time);
+
+		i = 0;
+		for (l = protocols; l; l = l->next) {
+			struct interface_info *ip;
+			ip = l->local;
+			if ((fds[i].revents & POLLIN)) {
+				fds[i].revents = 0;
+				if (ip && (l->handler != got_one ||
+				    !ip->dead))
+					(*(l->handler))(l);
+				if (interfaces_invalidated)
+					break;
+			}
+			i++;
+		}
+		interfaces_invalidated = 0;
+	} while (1);
+}
+
+
+void
+got_one(struct protocol *l)
+{
+	struct sockaddr_in from;
+	struct hardware hfrom;
+	struct iaddr ifrom;
+	size_t result;
+	union {
+		/*
+		 * Packet input buffer.  Must be as large as largest
+		 * possible MTU.
+		 */
+		unsigned char packbuf[4095];
+		struct dhcp_packet packet;
+	} u;
+	struct interface_info *ip = l->local;
+
+	if ((result = receive_packet(ip, u.packbuf, sizeof(u), &from,
+	    &hfrom)) == -1) {
+		warn("receive_packet failed on %s: %s", ip->name,
+		    strerror(errno));
+		ip->errors++;
+		if ((!interface_status(ip)) ||
+		    (ip->noifmedia && ip->errors > 20)) {
+			/* our interface has gone away. */
+			warn("Interface %s no longer appears valid.",
+			    ip->name);
+			ip->dead = 1;
+			interfaces_invalidated = 1;
+			close(l->fd);
+			remove_protocol(l);
+			free(ip);
+		}
+		return;
+	}
+	if (result == 0)
+		return;
+
+	if (bootp_packet_handler) {
+		ifrom.len = 4;
+		memcpy(ifrom.iabuf, &from.sin_addr, ifrom.len);
+
+		(*bootp_packet_handler)(ip, &u.packet, result,
+		    from.sin_port, ifrom, &hfrom);
+	}
+}
+
+int
+interface_status(struct interface_info *ifinfo)
+{
+	char *ifname = ifinfo->name;
+	int ifsock = ifinfo->rfdesc;
+	struct ifreq ifr;
+	struct ifmediareq ifmr;
+
+	/* get interface flags */
+	memset(&ifr, 0, sizeof(ifr));
+	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+	if (ioctl(ifsock, SIOCGIFFLAGS, &ifr) < 0) {
+		syslog(LOG_ERR, "ioctl(SIOCGIFFLAGS) on %s: %m", ifname);
+		goto inactive;
+	}
+	/*
+	 * if one of UP and RUNNING flags is dropped,
+	 * the interface is not active.
+	 */
+	if ((ifr.ifr_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
+		goto inactive;
+	}
+	/* Next, check carrier on the interface, if possible */
+	if (ifinfo->noifmedia)
+		goto active;
+	memset(&ifmr, 0, sizeof(ifmr));
+	strlcpy(ifmr.ifm_name, ifname, sizeof(ifmr.ifm_name));
+	if (ioctl(ifsock, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0) {
+		if (errno != EINVAL) {
+			syslog(LOG_DEBUG, "ioctl(SIOCGIFMEDIA) on %s: %m",
+			    ifname);
+
+			ifinfo->noifmedia = 1;
+			goto active;
+		}
+		/*
+		 * EINVAL (or ENOTTY) simply means that the interface
+		 * does not support the SIOCGIFMEDIA ioctl. We regard it alive.
+		 */
+		ifinfo->noifmedia = 1;
+		goto active;
+	}
+	if (ifmr.ifm_status & IFM_AVALID) {
+		switch (ifmr.ifm_active & IFM_NMASK) {
+		case IFM_ETHER:
+			if (ifmr.ifm_status & IFM_ACTIVE)
+				goto active;
+			else
+				goto inactive;
+			break;
+		default:
+			goto inactive;
+		}
+	}
+inactive:
+	return (0);
+active:
+	return (1);
+}
+
+void
+add_timeout(time_t when, void (*where)(void *), void *what)
+{
+	struct timeout *t, *q;
+
+	/* See if this timeout supersedes an existing timeout. */
+	t = NULL;
+	for (q = timeouts; q; q = q->next) {
+		if (q->func == where && q->what == what) {
+			if (t)
+				t->next = q->next;
+			else
+				timeouts = q->next;
+			break;
+		}
+		t = q;
+	}
+
+	/* If we didn't supersede a timeout, allocate a timeout
+	   structure now. */
+	if (!q) {
+		if (free_timeouts) {
+			q = free_timeouts;
+			free_timeouts = q->next;
+			q->func = where;
+			q->what = what;
+		} else {
+			q = malloc(sizeof(struct timeout));
+			if (!q)
+				error("Can't allocate timeout structure!");
+			q->func = where;
+			q->what = what;
+		}
+	}
+
+	q->when = when;
+
+	/* Now sort this timeout into the timeout list. */
+
+	/* Beginning of list? */
+	if (!timeouts || timeouts->when > q->when) {
+		q->next = timeouts;
+		timeouts = q;
+		return;
+	}
+
+	/* Middle of list? */
+	for (t = timeouts; t->next; t = t->next) {
+		if (t->next->when > q->when) {
+			q->next = t->next;
+			t->next = q;
+			return;
+		}
+	}
+
+	/* End of list. */
+	t->next = q;
+	q->next = NULL;
+}
+
+void
+cancel_timeout(void (*where)(void *), void *what)
+{
+	struct timeout *t, *q;
+
+	/* Look for this timeout on the list, and unlink it if we find it. */
+	t = NULL;
+	for (q = timeouts; q; q = q->next) {
+		if (q->func == where && q->what == what) {
+			if (t)
+				t->next = q->next;
+			else
+				timeouts = q->next;
+			break;
+		}
+		t = q;
+	}
+
+	/* If we found the timeout, put it on the free list. */
+	if (q) {
+		q->next = free_timeouts;
+		free_timeouts = q;
+	}
+}
+
+/* Add a protocol to the list of protocols... */
+void
+add_protocol(char *name, int fd, void (*handler)(struct protocol *),
+    void *local)
+{
+	struct protocol *p;
+
+	p = malloc(sizeof(*p));
+	if (!p)
+		error("can't allocate protocol struct for %s", name);
+
+	p->fd = fd;
+	p->handler = handler;
+	p->local = local;
+	p->next = protocols;
+	protocols = p;
+}
+
+void
+remove_protocol(struct protocol *proto)
+{
+	struct protocol *p, *next, *prev;
+
+	prev = NULL;
+	for (p = protocols; p; p = next) {
+		next = p->next;
+		if (p == proto) {
+			if (prev)
+				prev->next = p->next;
+			else
+				protocols = p->next;
+			free(p);
+		}
+	}
+}
+
+int
+interface_link_status(char *ifname)
+{
+	struct ifmediareq ifmr;
+	int sock;
+
+	if ((sock = socket (AF_INET, SOCK_DGRAM, 0)) == -1)
+		error("Can't create socket");
+
+	memset(&ifmr, 0, sizeof(ifmr));
+	strlcpy(ifmr.ifm_name, ifname, sizeof(ifmr.ifm_name));
+	if (ioctl(sock, SIOCGIFMEDIA, (caddr_t)&ifmr) == -1) {
+		/* EINVAL -> link state unknown. treat as active */
+		if (errno != EINVAL)
+			syslog(LOG_DEBUG, "ioctl(SIOCGIFMEDIA) on %s: %m",
+			    ifname);
+		close(sock);
+		return (1);
+	}
+	close(sock);
+
+	if (ifmr.ifm_status & IFM_AVALID) {
+		if ((ifmr.ifm_active & IFM_NMASK) == IFM_ETHER) {
+			if (ifmr.ifm_status & IFM_ACTIVE)
+				return (1);
+			else
+				return (0);
+		}
+	}
+	return (1);
+}