Add an event loop.

Split client.c into smaller files and functions and
recode around the event loop.
Add multiple interface support using the new event loop.
Document changes and outstanding bugs.

1 files changed, 204 insertions, 0 deletions

diff --git a/arp.c b/arp.c
new file mode 100644
index 00000000..71431dc8
--- /dev/null
+++ b/arp.c
@@ -0,0 +1,204 @@
+/* 
+ * dhcpcd - DHCP client daemon
+ * Copyright 2006-2008 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "arp.h"
+#include "bind.h"
+#include "common.h"
+#include "dhcpcd.h"
+#include "eloop.h"
+#include "if-options.h"
+#include "ipv4ll.h"
+#include "logger.h"
+#include "net.h"
+
+static void
+handle_arp_failure(struct interface *iface)
+{
+	if (IN_LINKLOCAL(htonl(iface->state->fail.s_addr))) {
+		handle_ipv4ll_failure(iface);
+		return;
+	}
+	send_decline(iface);
+	close_sockets(iface);
+	add_timeout_sec(DHCP_ARP_FAIL, start_interface, iface);
+}
+
+void
+handle_arp_packet(struct interface *iface)
+{
+	struct arphdr reply;
+	uint32_t reply_s;
+	uint32_t reply_t;
+	uint8_t arp_reply[sizeof(reply) + 2 * sizeof(reply_s) + 2 * HWADDR_LEN];
+	uint8_t *hw_s, *hw_t;
+	ssize_t bytes;
+	struct if_state *state = iface->state;
+
+	state->fail.s_addr = 0;
+	for(;;) {
+		bytes = get_raw_packet(iface, ETHERTYPE_ARP,
+				       arp_reply, sizeof(arp_reply));
+		if (bytes == 0 || bytes == -1)
+			return;
+		/* We must have a full ARP header */
+		if ((size_t)bytes < sizeof(reply))
+			continue;
+		memcpy(&reply, arp_reply, sizeof(reply));
+		/* Protocol must be IP. */
+		if (reply.ar_pro != htons(ETHERTYPE_IP))
+			continue;
+		if (reply.ar_pln != sizeof(reply_s))
+			continue;
+		/* Only these types are recognised */
+		if (reply.ar_op != htons(ARPOP_REPLY) &&
+		    reply.ar_op != htons(ARPOP_REQUEST))
+			continue;
+
+		/* Get pointers to the hardware addreses */
+		hw_s = arp_reply + sizeof(reply);
+		hw_t = hw_s + reply.ar_hln + reply.ar_pln;
+		/* Ensure we got all the data */
+		if ((hw_t + reply.ar_hln + reply.ar_pln) - arp_reply > bytes)
+			continue;
+		/* Ignore messages from ourself */
+		if (reply.ar_hln == iface->hwlen &&
+		    memcmp(hw_s, iface->hwaddr, iface->hwlen) == 0)
+			continue;
+		/* Copy out the IP addresses */
+		memcpy(&reply_s, hw_s + reply.ar_hln, reply.ar_pln);
+		memcpy(&reply_t, hw_t + reply.ar_hln, reply.ar_pln);
+
+		/* Check for conflict */
+		if (state->offer && 
+		    (reply_s == state->offer->yiaddr ||
+		     (reply_s == 0 && reply_t == state->offer->yiaddr)))
+			state->fail.s_addr = state->offer->yiaddr;
+
+		/* Handle IPv4LL conflicts */
+		if (IN_LINKLOCAL(htonl(iface->addr.s_addr)) &&
+		    (reply_s == iface->addr.s_addr ||
+		     (reply_s == 0 && reply_t == iface->addr.s_addr)))
+			state->fail.s_addr = iface->addr.s_addr;
+
+		if (state->fail.s_addr) {
+			logger(LOG_ERR, "%s: hardware address %s claims %s",
+			       iface->name,
+			       hwaddr_ntoa((unsigned char *)hw_s,
+					   (size_t)reply.ar_hln),
+			       inet_ntoa(state->fail));
+			errno = EEXIST;
+			handle_arp_failure(iface);
+			return;
+		}
+	}
+}
+
+void
+send_arp_announce(struct interface *iface)
+{
+	struct if_state *state = iface->state;
+	struct timeval tv;
+
+	if (iface->arp_fd == -1) {
+		open_socket(iface, ETHERTYPE_ARP);
+		add_event(iface->arp_fd, handle_arp_packet, iface);
+	}
+	if (++state->claims < ANNOUNCE_NUM)	
+		logger(LOG_DEBUG,
+		       "%s: sending ARP announce (%d of %d), "
+		       "next in %d.00 seconds",
+		       iface->name, state->claims, ANNOUNCE_NUM, ANNOUNCE_WAIT);
+	else
+		logger(LOG_DEBUG,
+		       "%s: sending ARP announce (%d of %d)",
+		       iface->name, state->claims, ANNOUNCE_NUM);
+	if (send_arp(iface, ARPOP_REQUEST,
+		     state->new->yiaddr, state->new->yiaddr) == -1)
+		logger(LOG_ERR, "send_arp: %s", strerror(errno));
+	if (state->claims < ANNOUNCE_NUM) {
+		add_timeout_sec(ANNOUNCE_WAIT, send_arp_announce, iface);
+		return;
+	}
+	if (IN_LINKLOCAL(htonl(state->new->yiaddr))) {
+		/* We should pretend to be at the end
+		 * of the DHCP negotation cycle */
+		state->interval = 64;
+		state->probes = 0;
+		state->claims = 0;
+		tv.tv_sec = state->interval - DHCP_RAND_MIN;
+		tv.tv_usec = arc4random() % (DHCP_RAND_MAX_U - DHCP_RAND_MIN_U);
+		tv.tv_sec = 3; /* test easier */
+		timernorm(&tv);
+		add_timeout_tv(&tv, start_discover, iface);
+	} else {
+		delete_event(iface->arp_fd);
+		close(iface->arp_fd);
+		iface->arp_fd = -1;
+	}
+}
+
+void
+send_arp_probe(struct interface *iface)
+{
+	struct if_state *state = iface->state;
+	struct in_addr addr;
+	struct timeval tv;
+
+	if (iface->arp_fd == -1) {
+		open_socket(iface, ETHERTYPE_ARP);
+		add_event(iface->arp_fd, handle_arp_packet, iface);
+	}
+	if (state->probes == 0) {
+		addr.s_addr = state->offer->yiaddr;
+		logger(LOG_INFO, "%s: checking %s is available"
+				" on attached networks",
+				iface->name, inet_ntoa(addr));
+	}
+	if (++state->probes < PROBE_NUM) {
+		tv.tv_sec = PROBE_MIN;
+		tv.tv_usec = arc4random() % (PROBE_MAX_U - PROBE_MIN_U);
+		timernorm(&tv);
+		add_timeout_tv(&tv, send_arp_probe, iface);
+	} else {
+		tv.tv_sec = ANNOUNCE_WAIT;
+		tv.tv_usec = 0;
+		if (IN_LINKLOCAL(htonl(state->offer->yiaddr)))
+			add_timeout_tv(&tv, bind_interface, iface);
+		else
+			add_timeout_tv(&tv, send_request, iface);
+	}
+	logger(LOG_DEBUG,
+		"%s: sending ARP probe (%d of %d), next in %0.2f seconds",
+		iface->name, state->probes, PROBE_NUM,  timeval_to_double(&tv));
+	if (send_arp(iface, ARPOP_REQUEST, 0, state->offer->yiaddr) == -1)
+		logger(LOG_ERR, "send_arp: %s", strerror(errno));
+}