Support parsing netlink route messages.
Bug: 9180552
Change-Id: I4a36d869ac692647fb226d0912285bdf2ffcb1fa
diff --git a/include/sysutils/NetlinkEvent.h b/include/sysutils/NetlinkEvent.h
index a247a74..c345cdb 100644
--- a/include/sysutils/NetlinkEvent.h
+++ b/include/sysutils/NetlinkEvent.h
@@ -37,6 +37,8 @@
const static int NlActionAddressUpdated;
const static int NlActionAddressRemoved;
const static int NlActionRdnss;
+ const static int NlActionRouteUpdated;
+ const static int NlActionRouteRemoved;
NetlinkEvent();
virtual ~NetlinkEvent();
@@ -55,6 +57,7 @@
bool parseIfInfoMessage(const struct nlmsghdr *nh);
bool parseIfAddrMessage(const struct nlmsghdr *nh);
bool parseUlogPacketMessage(const struct nlmsghdr *nh);
+ bool parseRtMessage(const struct nlmsghdr *nh);
bool parseNdUserOptMessage(const struct nlmsghdr *nh);
};
diff --git a/libsysutils/src/NetlinkEvent.cpp b/libsysutils/src/NetlinkEvent.cpp
index 41bd215..9d596ef 100644
--- a/libsysutils/src/NetlinkEvent.cpp
+++ b/libsysutils/src/NetlinkEvent.cpp
@@ -48,6 +48,8 @@
const int NetlinkEvent::NlActionAddressUpdated = 6;
const int NetlinkEvent::NlActionAddressRemoved = 7;
const int NetlinkEvent::NlActionRdnss = 8;
+const int NetlinkEvent::NlActionRouteUpdated = 9;
+const int NetlinkEvent::NlActionRouteRemoved = 10;
NetlinkEvent::NetlinkEvent() {
mAction = NlActionUnknown;
@@ -270,6 +272,98 @@
}
/*
+ * Parse a RTM_NEWROUTE or RTM_DELROUTE message.
+ */
+bool NetlinkEvent::parseRtMessage(const struct nlmsghdr *nh) {
+ uint8_t type = nh->nlmsg_type;
+ const char *msgname = rtMessageName(type);
+
+ // Sanity check.
+ if (type != RTM_NEWROUTE && type != RTM_DELROUTE) {
+ SLOGE("%s: incorrect message type %d (%s)\n", __func__, type, msgname);
+ return false;
+ }
+
+ struct rtmsg *rtm = (struct rtmsg *) NLMSG_DATA(nh);
+ if (!checkRtNetlinkLength(nh, sizeof(*rtm)))
+ return false;
+
+ if (// Ignore static routes we've set up ourselves.
+ (rtm->rtm_protocol != RTPROT_KERNEL &&
+ rtm->rtm_protocol != RTPROT_RA) ||
+ // We're only interested in global unicast routes.
+ (rtm->rtm_scope != RT_SCOPE_UNIVERSE) ||
+ (rtm->rtm_type != RTN_UNICAST) ||
+ // We don't support source routing.
+ (rtm->rtm_src_len != 0) ||
+ // Cloned routes aren't real routes.
+ (rtm->rtm_flags & RTM_F_CLONED)) {
+ return false;
+ }
+
+ int family = rtm->rtm_family;
+ int prefixLength = rtm->rtm_dst_len;
+
+ // Currently we only support: destination, (one) next hop, ifindex.
+ char dst[INET6_ADDRSTRLEN] = "";
+ char gw[INET6_ADDRSTRLEN] = "";
+ char dev[IFNAMSIZ] = "";
+
+ size_t len = RTM_PAYLOAD(nh);
+ struct rtattr *rta;
+ for (rta = RTM_RTA(rtm); RTA_OK(rta, len); rta = RTA_NEXT(rta, len)) {
+ switch (rta->rta_type) {
+ case RTA_DST:
+ if (maybeLogDuplicateAttribute(*dst, "RTA_DST", msgname))
+ continue;
+ if (!inet_ntop(family, RTA_DATA(rta), dst, sizeof(dst)))
+ return false;
+ continue;
+ case RTA_GATEWAY:
+ if (maybeLogDuplicateAttribute(*gw, "RTA_GATEWAY", msgname))
+ continue;
+ if (!inet_ntop(family, RTA_DATA(rta), gw, sizeof(gw)))
+ return false;
+ continue;
+ case RTA_OIF:
+ if (maybeLogDuplicateAttribute(*dev, "RTA_OIF", msgname))
+ continue;
+ if (!if_indextoname(* (int *) RTA_DATA(rta), dev))
+ return false;
+ default:
+ continue;
+ }
+ }
+
+ // If there's no RTA_DST attribute, then:
+ // - If the prefix length is zero, it's the default route.
+ // - If the prefix length is nonzero, there's something we don't understand.
+ // Ignore the event.
+ if (!*dst && !prefixLength) {
+ if (family == AF_INET) {
+ strncpy(dst, "0.0.0.0", sizeof(dst));
+ } else if (family == AF_INET6) {
+ strncpy(dst, "::", sizeof(dst));
+ }
+ }
+
+ // A useful route must have a destination and at least either a gateway or
+ // an interface.
+ if (!*dst || (!*gw && !*dev))
+ return false;
+
+ // Fill in netlink event information.
+ mAction = (type == RTM_NEWROUTE) ? NlActionRouteUpdated :
+ NlActionRouteRemoved;
+ mSubsystem = strdup("net");
+ asprintf(&mParams[0], "ROUTE=%s/%d", dst, prefixLength);
+ asprintf(&mParams[1], "GATEWAY=%s", (*gw) ? gw : "");
+ asprintf(&mParams[2], "INTERFACE=%s", (*dev) ? dev : "");
+
+ return true;
+}
+
+/*
* Parse a RTM_NEWNDUSEROPT message.
*/
bool NetlinkEvent::parseNdUserOptMessage(const struct nlmsghdr *nh) {
@@ -408,6 +502,11 @@
if (parseIfAddrMessage(nh))
return true;
+ } else if (nh->nlmsg_type == RTM_NEWROUTE ||
+ nh->nlmsg_type == RTM_DELROUTE) {
+ if (parseRtMessage(nh))
+ return true;
+
} else if (nh->nlmsg_type == RTM_NEWNDUSEROPT) {
if (parseNdUserOptMessage(nh))
return true;