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authorJakub Hrozek <jhrozek@redhat.com>2011-09-04 21:15:43 +0200
committerStephen Gallagher <sgallagh@redhat.com>2011-09-06 14:40:13 -0400
commit4e3495b3b8927a282adc48cc80f0611ecf79821b (patch)
tree53e64fd76bb484c7abb5331de35f57a2a79f633c
parent172bf27813151351a1ff8284a3d524660eca2efe (diff)
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Subscribe to netlink route and addr messages
https://fedorahosted.org/sssd/ticket/955 In addition to carrier up messages, also subscribe to any messages describing that an address has been added or removed or routing table changed.
-rw-r--r--src/monitor/monitor_netlink.c249
1 files changed, 244 insertions, 5 deletions
diff --git a/src/monitor/monitor_netlink.c b/src/monitor/monitor_netlink.c
index 737266bf..7bc90efc 100644
--- a/src/monitor/monitor_netlink.c
+++ b/src/monitor/monitor_netlink.c
@@ -27,6 +27,8 @@
#include <sys/ioctl.h>
#define __USE_GNU /* needed for struct ucred */
#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
#include <unistd.h>
#include <fcntl.h>
@@ -43,6 +45,7 @@
#include <netlink/route/addr.h>
#include <netlink/route/link.h>
#include <netlink/route/rtnl.h>
+#include <netlink/route/route.h>
#include <netlink/handlers.h>
#endif
@@ -65,6 +68,13 @@
#define BUFSIZE 8
+enum nlw_msg_type {
+ NLW_LINK,
+ NLW_ROUTE,
+ NLW_ADDR,
+ NLW_OTHER
+};
+
struct netlink_ctx {
#ifdef HAVE_LIBNL
struct nl_handle *nlh;
@@ -220,6 +230,26 @@ static bool discard_iff_up(const char *ifname)
return false;
}
+static void nladdr_to_string(struct nl_addr *nl, char *buf, size_t bufsize)
+{
+ int addr_family;
+ void *addr;
+
+ addr_family = nl_addr_get_family(nl);
+ if (addr_family != AF_INET && addr_family != AF_INET6) {
+ strncpy(buf, "unknown", bufsize);
+ return;
+ }
+
+ addr = nl_addr_get_binary_addr(nl);
+ if (!addr) return;
+
+ if (inet_ntop(addr_family, addr, buf, bufsize) == NULL) {
+ DEBUG(SSSDBG_MINOR_FAILURE, ("inet_ntop failed\n"));
+ snprintf(buf, bufsize, "unknown");
+ }
+}
+
/*******************************************************************
* Wrappers for different capabilities of different libnl versions
*******************************************************************/
@@ -257,6 +287,48 @@ static bool nlw_accept_message(struct nl_handle *nlh,
return accept_msg;
}
+static bool nlw_is_addr_object(struct nl_object *obj)
+{
+ bool is_addr_object = true;
+ struct rtnl_addr *filter;
+
+ filter = rtnl_addr_alloc();
+ if (!filter) {
+ DEBUG(SSSDBG_CRIT_FAILURE, ("Allocation error!\n"));
+ is_addr_object = false;
+ }
+
+ /* Ensure it's an addr object */
+ if (!nlw_object_match(obj, OBJ_CAST(filter))) {
+ DEBUG(SSSDBG_MINOR_FAILURE, ("Not an addr object\n"));
+ is_addr_object = false;
+ }
+
+ rtnl_addr_put(filter);
+ return is_addr_object;
+}
+
+static bool nlw_is_route_object(struct nl_object *obj)
+{
+ bool is_route_object = true;
+ struct rtnl_route *filter;
+
+ filter = rtnl_route_alloc();
+ if (!filter) {
+ DEBUG(SSSDBG_CRIT_FAILURE, ("Allocation error!\n"));
+ is_route_object = false;
+ }
+
+ /* Ensure it's a route object */
+ if (!nlw_object_match(obj, OBJ_CAST(filter))) {
+ DEBUG(SSSDBG_MINOR_FAILURE, ("Not a route object\n"));
+ is_route_object = false;
+ }
+
+ rtnl_route_put(filter);
+ return is_route_object;
+}
+
static bool nlw_is_link_object(struct nl_object *obj)
{
bool is_link_object = true;
@@ -287,19 +359,18 @@ static int nlw_enable_passcred(struct nl_handle *nlh)
#endif
}
-static int nlw_group_subscribe(struct nl_handle *nlh)
+static int nlw_group_subscribe(struct nl_handle *nlh, int group)
{
int ret;
#ifdef HAVE_NL_SOCKET_ADD_MEMBERSHIP
- ret = nl_socket_add_membership(nlh, RTNLGRP_LINK);
+ ret = nl_socket_add_membership(nlh, group);
if (ret != 0) {
DEBUG(1, ("Unable to add membership: %s\n", nl_geterror()));
return ret;
}
#else
int nlfd = nlw_get_fd(nlh);
- int group = RTNLGRP_LINK;
errno = 0;
ret = setsockopt(nlfd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP,
@@ -314,6 +385,19 @@ static int nlw_group_subscribe(struct nl_handle *nlh)
return 0;
}
+static int nlw_groups_subscribe(struct nl_handle *nlh, int *groups)
+{
+ int ret;
+ int i;
+
+ for (i=0; groups[i]; i++) {
+ ret = nlw_group_subscribe(nlh, groups[i]);
+ if (ret != EOK) return ret;
+ }
+
+ return EOK;
+}
+
/*******************************************************************
* Callbacks for validating and receiving messages
*******************************************************************/
@@ -343,10 +427,50 @@ static int event_msg_recv(struct nl_msg *msg, void *arg)
}
static void link_msg_handler(struct nl_object *obj, void *arg);
+static void route_msg_handler(struct nl_object *obj, void *arg);
+static void addr_msg_handler(struct nl_object *obj, void *arg);
+
+static enum nlw_msg_type message_type(struct nlmsghdr *hdr)
+{
+ DEBUG(SSSDBG_FUNC_DATA, ("netlink Message type: %d\n", hdr->nlmsg_type));
+ switch (hdr->nlmsg_type) {
+ /* network interface added */
+ case RTM_NEWLINK:
+ return NLW_LINK;
+ /* routing table changed */
+ case RTM_NEWROUTE:
+ case RTM_DELROUTE:
+ return NLW_ROUTE;
+ /* IP address added or deleted */
+ case RTM_NEWADDR:
+ case RTM_DELADDR:
+ return NLW_ADDR;
+ /* Something else happened, but we don't care (typically RTM_GET* ) */
+ default:
+ return NLW_OTHER;
+ }
+
+ return NLW_OTHER;
+}
static int event_msg_ready(struct nl_msg *msg, void *arg)
{
- nl_msg_parse(msg, &link_msg_handler, arg);
+ struct nlmsghdr *hdr = nlmsg_hdr(msg);
+
+ switch (message_type(hdr)) {
+ case NLW_LINK:
+ nl_msg_parse(msg, &link_msg_handler, arg);
+ break;
+ case NLW_ROUTE:
+ nl_msg_parse(msg, &route_msg_handler, arg);
+ break;
+ case NLW_ADDR:
+ nl_msg_parse(msg, &addr_msg_handler, arg);
+ break;
+ default:
+ return EOK; /* Don't care */
+ }
+
return NLW_OK;
}
@@ -378,6 +502,119 @@ static int nlw_set_callbacks(struct nl_handle *nlh, void *data)
return ret;
}
+static void route_msg_debug_print(struct rtnl_route *route_obj)
+{
+ int prefixlen;
+ char buf[INET6_ADDRSTRLEN];
+ struct nl_addr *nl;
+
+ nl = rtnl_route_get_dst(route_obj);
+ if (nl) {
+ nladdr_to_string(nl, buf, INET6_ADDRSTRLEN);
+ prefixlen = nl_addr_get_prefixlen(nl);
+ } else {
+ strncpy(buf, "unknown", INET6_ADDRSTRLEN);
+ prefixlen = 0;
+ }
+
+ DEBUG(SSSDBG_TRACE_LIBS, ("route idx %d flags %#X family %d addr %s/%d\n",
+ rtnl_route_get_oif(route_obj), rtnl_route_get_flags(route_obj),
+ rtnl_route_get_family(route_obj), buf, prefixlen));
+}
+
+/*
+ * If a bridge interface is configured it sets up a timer to requery for
+ * multicast group memberships periodically. We need to discard such
+ * messages.
+ */
+static bool route_is_multicast(struct rtnl_route *route_obj)
+{
+ struct nl_addr *nl;
+ struct in6_addr *addr6 = NULL;
+ struct in_addr *addr4 = NULL;
+
+ nl = rtnl_route_get_dst(route_obj);
+ if (!nl) {
+ DEBUG(SSSDBG_MINOR_FAILURE, ("A route with no destination?\n"));
+ return false;
+ }
+
+ if (nl_addr_get_family(nl) == AF_INET) {
+ addr4 = nl_addr_get_binary_addr(nl);
+ if (!addr4) {
+ return false;
+ }
+
+ return IN_MULTICAST(addr4->s_addr);
+ } else if (nl_addr_get_family(nl) == AF_INET6) {
+ addr6 = nl_addr_get_binary_addr(nl);
+ if (!addr6) {
+ return false;
+ }
+
+ return IN6_IS_ADDR_MULTICAST(addr6);
+ }
+
+ DEBUG(SSSDBG_MINOR_FAILURE, ("Unknown route address family\n"));
+ return false;
+}
+
+static void route_msg_handler(struct nl_object *obj, void *arg)
+{
+ struct rtnl_route *route_obj;
+ struct netlink_ctx *ctx = (struct netlink_ctx *) arg;
+
+ if (!nlw_is_route_object(obj)) return;
+
+ route_obj = (struct rtnl_route *) obj;
+
+ if (route_is_multicast(route_obj)) {
+ DEBUG(SSSDBG_TRACE_INTERNAL,
+ ("Discarding multicast route message\n"));
+ return;
+ }
+
+ if (debug_level & SSSDBG_TRACE_LIBS) {
+ route_msg_debug_print(route_obj);
+ }
+
+ ctx->change_cb(ctx->cb_data);
+}
+
+static void addr_msg_debug_print(struct rtnl_addr *addr_obj)
+{
+ unsigned int flags;
+ char str_flags[512];
+ int ifidx;
+ struct nl_addr *local_addr;
+ char buf[INET6_ADDRSTRLEN];
+
+ flags = rtnl_addr_get_flags(addr_obj);
+ ifidx = rtnl_addr_get_ifindex(addr_obj);
+ local_addr = rtnl_addr_get_local(addr_obj);
+
+ rtnl_addr_flags2str(flags, str_flags, 512);
+ nladdr_to_string(local_addr, buf, INET6_ADDRSTRLEN);
+
+ DEBUG(SSSDBG_TRACE_LIBS, ("netlink addr message: iface idx %u "
+ "addr %s flags 0x%X (%s)\n", ifidx, buf, flags, str_flags));
+}
+
+static void addr_msg_handler(struct nl_object *obj, void *arg)
+{
+ struct netlink_ctx *ctx = (struct netlink_ctx *) arg;
+ struct rtnl_addr *addr_obj;
+
+ if (!nlw_is_addr_object(obj)) return;
+
+ addr_obj = (struct rtnl_addr *) obj;
+ if (debug_level & SSSDBG_TRACE_LIBS) {
+ addr_msg_debug_print(addr_obj);
+ }
+
+ ctx->change_cb(ctx->cb_data);
+}
+
static void link_msg_handler(struct nl_object *obj, void *arg)
{
struct netlink_ctx *ctx = (struct netlink_ctx *) arg;
@@ -436,6 +673,8 @@ int setup_netlink(TALLOC_CTX *mem_ctx, struct tevent_context *ev,
int ret;
int nlfd;
unsigned flags;
+ int groups[] = { RTNLGRP_LINK, RTNLGRP_IPV4_ROUTE, RTNLGRP_IPV6_ROUTE,
+ RTNLGRP_IPV4_IFADDR, RTNLGRP_IPV6_IFADDR, 0 };
nlctx = talloc_zero(mem_ctx, struct netlink_ctx);
if (!nlctx) return ENOMEM;
@@ -477,7 +716,7 @@ int setup_netlink(TALLOC_CTX *mem_ctx, struct tevent_context *ev,
}
/* Subscribe to the LINK group for internal carrier signals */
- ret = nlw_group_subscribe(nlctx->nlh);
+ ret = nlw_groups_subscribe(nlctx->nlh, groups);
if (ret != 0) {
DEBUG(1, ("Unable to subscribe to netlink monitor\n"));
ret = EIO;