ClatUtils - implement openNetlinkSocket()
Test: atest netd_unit_test
Bug: 65674744
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I652185296c8e92b5e4887e39baad8a3fec034cf7
diff --git a/server/ClatUtils.cpp b/server/ClatUtils.cpp
index e972513..9790d26 100644
--- a/server/ClatUtils.cpp
+++ b/server/ClatUtils.cpp
@@ -18,6 +18,7 @@
#include <errno.h>
#include <linux/if.h>
+#include <linux/netlink.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>
@@ -26,6 +27,7 @@
#define LOG_TAG "ClatUtils"
#include <log/log.h>
+#include "NetlinkCommands.h"
#include "android-base/unique_fd.h"
#include "bpf/BpfUtils.h"
#include "netdbpf/bpf_shared.h"
@@ -67,5 +69,39 @@
return (fd == -1) ? -errno : fd;
}
+// TODO: use //system/netd/server/NetlinkCommands.cpp:openNetlinkSocket(protocol)
+int openNetlinkSocket(void) {
+ base::unique_fd fd(socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE));
+ if (fd == -1) {
+ const int err = errno;
+ ALOGE("socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE)");
+ return -err;
+ }
+
+ int rv;
+
+ const int on = 1;
+ rv = setsockopt(fd, SOL_NETLINK, NETLINK_CAP_ACK, &on, sizeof(on));
+ if (rv) ALOGE("setsockopt(fd, SOL_NETLINK, NETLINK_CAP_ACK, %d)", on);
+
+ // this is needed to get sane strace netlink parsing, it allocates the pid
+ rv = bind(fd, (const struct sockaddr*)&KERNEL_NLADDR, sizeof(KERNEL_NLADDR));
+ if (rv) {
+ const int err = errno;
+ ALOGE("bind(fd, {AF_NETLINK, 0, 0})");
+ return -err;
+ }
+
+ // we do not want to receive messages from anyone besides the kernel
+ rv = connect(fd, (const struct sockaddr*)&KERNEL_NLADDR, sizeof(KERNEL_NLADDR));
+ if (rv) {
+ const int err = errno;
+ ALOGE("connect(fd, {AF_NETLINK, 0, 0})");
+ return -err;
+ }
+
+ return fd.release();
+}
+
} // namespace net
} // namespace android