1 files changed, 344 insertions, 0 deletions
diff --git a/src/pingu_iface.c b/src/pingu_iface.c
new file mode 100644
index 0000000..815b1e9
--- /dev/null
+++ b/src/pingu_iface.c
@@ -0,0 +1,344 @@
+
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <linux/rtnetlink.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+
+#include <ev.h>
+
+#include "list.h"
+#include "log.h"
+#include "pingu_burst.h"
+#include "pingu_host.h"
+#include "pingu_iface.h"
+#include "pingu_ping.h"
+#include "pingu_netlink.h"
+#include "sockaddr_util.h"
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifndef HAVE_STRLCPY
+#define	strlcpy(dst, src, dstsize)	snprintf(dst, dstsize, "%s", src)
+#endif
+
+static struct list_head iface_list = LIST_INITIALIZER(iface_list);
+
+#define PINGU_ROUTE_TABLE_MIN 1
+#define PINGU_ROUTE_TABLE_MAX 253
+unsigned char used_route_table[256];
+
+/* do we have any load-balance at all? */
+static int load_balanced = 0;
+
+static void pingu_iface_socket_cb(struct ev_loop *loop, struct ev_io *w,
+				 int revents)
+{
+	struct pingu_iface *iface = container_of(w, struct pingu_iface, socket_watcher);
+
+	if (revents & EV_READ)
+		pingu_ping_read_reply(loop, iface);
+}
+
+int pingu_iface_bind_socket(struct pingu_iface *iface, int log_error)
+{
+	int r;
+	if (iface->name[0] == '\0')
+		return 0;
+	r = setsockopt(iface->fd, SOL_SOCKET, SO_BINDTODEVICE, iface->name,
+		       strlen(iface->name));
+	if (r < 0 && log_error)
+		log_perror(iface->name);
+
+	r = bind(iface->fd, &iface->primary_addr.sa,
+		 sockaddr_len(&iface->primary_addr));
+	if (r < 0 && log_error)
+		log_perror(iface->name);
+	iface->has_binding = (r == 0);
+	return r;
+}
+
+static int pingu_iface_init_socket(struct ev_loop *loop,
+				   struct pingu_iface *iface)
+{
+	iface->fd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
+	if (iface->fd < 0) {
+		log_perror("socket");
+		return -1;
+	}
+
+	ev_io_init(&iface->socket_watcher, pingu_iface_socket_cb,
+		   iface->fd, EV_READ);
+	ev_io_start(loop, &iface->socket_watcher);
+	return 0;
+}
+
+int pingu_iface_usable(struct pingu_iface *iface)
+{
+	if (iface->name[0] == '\0')
+		return 1;
+	return iface->has_link && iface->has_address && iface->has_binding;
+}
+
+struct pingu_iface *pingu_iface_get_by_name(const char *name)
+{
+	struct pingu_iface *iface;
+	list_for_each_entry(iface, &iface_list, iface_list_entry) {
+		if (name == NULL) {
+			if (iface->name[0] == '\0')
+				return iface;
+		} else if (strncmp(name, iface->name, sizeof(iface->name)) == 0) {
+			return iface;
+		}
+	}
+	return NULL;
+}
+
+struct pingu_iface *pingu_iface_get_by_index(int index)
+{
+	struct pingu_iface *iface;
+	list_for_each_entry(iface, &iface_list, iface_list_entry) {
+		if (iface->index == index)
+			return iface;
+	}
+	return NULL;
+}
+
+struct pingu_iface *pingu_iface_get_by_name_or_new(const char *name)
+{
+	struct pingu_iface *iface = pingu_iface_get_by_name(name);
+	if (iface != NULL)
+		return iface;
+
+	iface = calloc(1, sizeof(struct pingu_iface));
+	if (iface == NULL) {
+		log_perror("calloc(iface)");
+		return NULL;
+	}
+
+	if (name != NULL)
+		strlcpy(iface->name, name, sizeof(iface->name));
+
+	list_init(&iface->ping_list);
+	list_init(&iface->route_list);
+	list_add(&iface->iface_list_entry, &iface_list);
+	return iface;
+}
+
+void pingu_iface_set_addr(struct pingu_iface *iface, int family,
+			  void *data, int len)
+{
+	sockaddr_init(&iface->primary_addr, family, data);
+	if (len <= 0 || data == NULL) {
+		iface->has_address = 0;
+		iface->has_binding = 0;
+		pingu_route_del_all(&iface->route_list);
+		log_debug("%s: address removed", iface->name);
+		return;
+	}
+	iface->has_address = 1;
+	log_debug("%s: new address: %s", iface->name,
+		inet_ntoa(iface->primary_addr.sin.sin_addr));
+}
+
+void pingu_iface_set_balance(struct pingu_iface *iface, int balance_weight)
+{
+	load_balanced++;
+	iface->balance = 1;
+	iface->balance_weight = balance_weight;
+}
+
+#if 0
+void pingu_route_dump(struct pingu_iface *iface)
+{
+	struct pingu_route *gw;
+	list_for_each_entry(gw, &iface->route_list, route_list_entry) {
+		char buf[64];
+		sockaddr_to_string(&gw->gw_addr, buf, sizeof(buf));
+		log_debug("dump: %s: via %s metric %i", iface->name, buf,
+			  gw->metric);
+	}
+}
+#endif
+
+void pingu_iface_gw_action(struct pingu_iface *iface,
+			 struct pingu_route *gw, int action)
+{
+	switch (action) {
+	case RTM_NEWROUTE:
+		pingu_route_add(&iface->route_list, gw);
+		log_debug("%s: added route", iface->name);
+		/* if we get a new default gateway for an interface
+		 * that is marked "down", remove the default gw again
+		 * from main table and let pingu detect that it went up
+		 *
+		 * This solves the case when dhcp will renew a lease,
+		 * recreates the default gw and ISP is broke a bit
+		 * futher down the road.
+		 */
+		if (is_default_gw(gw) && !pingu_iface_gw_is_online(iface)) {
+			pingu_iface_update_routes(iface, RTM_DELROUTE);
+			/* avoid doing the multipath twice*/
+			return;
+		}
+		break;
+	case RTM_DELROUTE:
+		pingu_route_del(&iface->route_list, gw);
+		log_debug("%s: removed route", iface->name);
+		break;
+	}
+	if (load_balanced > 1 && is_default_gw(gw))
+		kernel_route_multipath(RTM_NEWROUTE, &iface_list, RT_TABLE_MAIN);
+}
+
+void pingu_iface_update_routes(struct pingu_iface *iface, int action)
+{
+	struct pingu_route *route;
+	list_for_each_entry(route, &iface->route_list, route_list_entry) {
+		if (is_default_gw(route) && iface->has_address)
+			kernel_route_modify(action, route, RT_TABLE_MAIN);
+	}
+	if (load_balanced > 1)
+		kernel_route_multipath(RTM_NEWROUTE, &iface_list, RT_TABLE_MAIN);
+}
+
+int pingu_iface_gw_is_online(struct pingu_iface *iface)
+{
+	return iface->hosts_online >= iface->required_hosts_online;
+}
+
+/* check if we should bring up/down this ISP */
+void pingu_iface_adjust_hosts_online(struct pingu_iface *iface, int adjustment)
+{
+	int old_status, new_status, route_action;
+	char *action, *statusstr;
+
+	old_status = pingu_iface_gw_is_online(iface);
+	iface->hosts_online += adjustment;
+	new_status = pingu_iface_gw_is_online(iface);
+
+	if (old_status == new_status)
+		return;
+
+	if (new_status) {
+		statusstr = "ONLINE";
+		route_action = RTM_NEWROUTE;
+		action = iface->gw_up_action;
+	} else {
+		statusstr = "OFFLINE";
+		route_action = RTM_DELROUTE;
+		action = iface->gw_down_action;
+	}
+
+	log_info("%s: went %s", iface->label ? iface->label : iface->name,
+		 statusstr);
+	pingu_iface_update_routes(iface, route_action);
+	execute_action(action);
+}
+
+int pingu_iface_set_route_table(struct pingu_iface *iface, int table)
+{
+	static int initialized = 0;
+	int i = 1;
+	if (!initialized) {
+		memset(used_route_table, 0, sizeof(used_route_table));
+		initialized = 1;
+	}
+	if (table == PINGU_ROUTE_TABLE_AUTO) {
+		while (i < 253 && used_route_table[i])
+			i++;
+		table = i;
+	}
+	if (table < PINGU_ROUTE_TABLE_MIN || table >= PINGU_ROUTE_TABLE_MAX) {
+		log_error("Invalid route table %i", table);
+		return -1;
+	}
+	used_route_table[table] = 1;
+	iface->route_table = table;
+	return table;
+}
+
+void pingu_iface_dump_status(int fd, char *filter)
+{
+	struct pingu_iface *iface;
+	char buf[512];
+	list_for_each_entry(iface, &iface_list, iface_list_entry) {
+		if (filter != NULL && strcmp(filter, iface->label) != 0)
+			continue;
+		snprintf(buf, sizeof(buf), "%s: %i\n",
+			 iface->label != NULL ? iface->label : iface->name,
+			 pingu_iface_gw_is_online(iface));
+		write(fd, buf, strlen(buf));
+	}
+	write(fd, "\n", 1);
+}
+
+void pingu_iface_dump_pings(int fd, char *filter)
+{
+	struct pingu_iface *iface;
+	list_for_each_entry(iface, &iface_list, iface_list_entry) {
+		if (filter != NULL && strcmp(filter, iface->name) != 0)
+			continue;
+		pingu_ping_dump(fd, &iface->ping_list, iface->name);
+	}
+	write(fd, "\n", 1);
+}
+
+void pingu_iface_dump_routes(int fd, char *filter)
+{
+	struct pingu_iface *iface;
+	list_for_each_entry(iface, &iface_list, iface_list_entry) {
+		if (filter != NULL && strcmp(filter, iface->name) != 0)
+			continue;
+		pingu_route_dump(fd, &iface->route_list);
+	}
+	write(fd, "\n", 1);
+}
+
+int pingu_iface_init(struct ev_loop *loop)
+{
+	struct pingu_iface *iface;
+	list_for_each_entry(iface, &iface_list, iface_list_entry) {
+		if (iface->route_table == 0)
+			pingu_iface_set_route_table(iface, PINGU_ROUTE_TABLE_AUTO);
+		if (pingu_iface_init_socket(loop, iface) == -1)
+			return -1;
+	}
+	if (load_balanced == 1)
+		log_warning("Only a single interface was configured with load-balance");
+	return 0;
+}
+
+void pingu_iface_cleanup(struct ev_loop *loop)
+{
+	struct pingu_iface *iface, *n;
+	/* remove loadbalance route */
+	if (load_balanced > 1) {
+		int err = kernel_route_multipath(RTM_DELROUTE, &iface_list, RT_TABLE_MAIN);
+		if (err > 0)
+			log_error("Failed to delete load-balance route: %s", strerror(err));
+	}
+
+	list_for_each_entry(iface, &iface_list, iface_list_entry) {
+		kernel_cleanup_iface_routes(iface);
+		close(iface->fd);
+	}
+	list_for_each_entry_safe(iface, n, &iface_list, iface_list_entry) {
+		list_del(&iface->iface_list_entry);
+		if (iface->label != NULL)
+			free(iface->label);
+		if (iface->gw_up_action != NULL)
+			free(iface->gw_up_action);
+		if (iface->gw_down_action != NULL)
+			free(iface->gw_down_action);
+		pingu_ping_cleanup(loop, &iface->ping_list);
+		pingu_route_cleanup(&iface->route_list);
+		free(iface);
+	}
+}