zebra: human readable netlink dumps

Add new compile option to enable human readable netlink dumps with
`debug zebra kernel msgdump`.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

configure.ac

@@ -673,6 +673,15 @@ AC_ARG_ENABLE([dev_build],
 AC_ARG_ENABLE([lua],
     AS_HELP_STRING([--enable-lua], [Build Lua scripting]))
 
+AC_ARG_ENABLE([netlink-debug],
+  AS_HELP_STRING([--disable-netlink-debug], [pretty print netlink debug messages]))
+
+if test "$enable_netlink_debug" != "no" ; then
+  AC_DEFINE([NETLINK_DEBUG], [1], [Netlink extra debugging code])
+fi
+
+AM_CONDITIONAL([NETLINK_DEBUG], [test "$enable_netlink_debug" != "no"])
+
 if test "$enable_time_check" != "no" ; then
   if test "$enable_time_check" = "yes" -o "$enable_time_check" = "" ; then
     AC_DEFINE([CONSUMED_TIME_CHECK], [5000000], [Consumed Time Check])

zebra/kernel_netlink.c

@@ -712,7 +712,11 @@ static ssize_t netlink_send_msg(const struct nlsock *nl, void *buf,
 
 	if (IS_ZEBRA_DEBUG_KERNEL_MSGDUMP_SEND) {
 		zlog_debug("%s: >> netlink message dump [sent]", __func__);
+#ifdef NETLINK_DEBUG
+		nl_dump(buf, buflen);
+#else
 		zlog_hexdump(buf, buflen);
+#endif /* NETLINK_DEBUG */
 	}
 
 	if (status == -1) {
@@ -770,7 +774,11 @@ static int netlink_recv_msg(const struct nlsock *nl, struct msghdr msg,
 
 	if (IS_ZEBRA_DEBUG_KERNEL_MSGDUMP_RECV) {
 		zlog_debug("%s: << netlink message dump [recv]", __func__);
+#ifdef NETLINK_DEBUG
+		nl_dump(buf, status);
+#else
 		zlog_hexdump(buf, status);
+#endif /* NETLINK_DEBUG */
 	}
 
 	return status;

zebra/rt_netlink.h

@@ -118,6 +118,29 @@ netlink_put_lsp_update_msg(struct nl_batch *bth, struct zebra_dplane_ctx *ctx);
 extern enum netlink_msg_status
 netlink_put_pw_update_msg(struct nl_batch *bth, struct zebra_dplane_ctx *ctx);
 
+#ifdef NETLINK_DEBUG
+const char *nlmsg_type2str(uint16_t type);
+const char *af_type2str(int type);
+const char *ifi_type2str(int type);
+const char *rta_type2str(int type);
+const char *rtm_type2str(int type);
+const char *rtm_protocol2str(int type);
+const char *rtm_scope2str(int type);
+const char *rtm_rta2str(int type);
+const char *neigh_rta2str(int type);
+const char *ifa_rta2str(int type);
+const char *nhm_rta2str(int type);
+const char *nlmsg_flags2str(uint16_t flags, char *buf, size_t buflen);
+const char *if_flags2str(uint32_t flags, char *buf, size_t buflen);
+const char *rtm_flags2str(uint32_t flags, char *buf, size_t buflen);
+const char *neigh_state2str(uint32_t flags, char *buf, size_t buflen);
+const char *neigh_flags2str(uint32_t flags, char *buf, size_t buflen);
+const char *ifa_flags2str(uint32_t flags, char *buf, size_t buflen);
+const char *nh_flags2str(uint32_t flags, char *buf, size_t buflen);
+
+void nl_dump(void *msg, size_t msglen);
+#endif /* NETLINK_DEBUG */
+
 #ifdef __cplusplus
 }
 #endif

zebra/subdir.am

@@ -220,3 +220,9 @@ zebra_dplane_fpm_nl_la_LIBADD  =
 
 vtysh_scan += $(top_srcdir)/zebra/dplane_fpm_nl.c
 endif
+
+if NETLINK_DEBUG
+zebra_zebra_SOURCES += \
+	zebra/debug_nl.c \
+	# end
+endif