netlink: refactor decode_nlmsg_flags

Refactor decode_nlmsg_flags to make it family-specific, just like
decode_nlmsg_type and decode_payload.

* netlink.c (decode_nlmsg_flags_crypto, decode_nlmsg_flags_route,
decode_nlmsg_flags_sock_diag, decode_nlmsg_flags_xfrm): New functions.
(nlmsg_flags_decoder_t): New typedef.
(nlmsg_flags): New array.
(decode_nlmsg_flags): Use it.

diff --git a/netlink.c b/netlink.c
index cdfe4ee8afa22934fe6a323f3384392280526e9a..f3868bd73573881d6adbfd2314d9843fdf00ac89 100644 (file)
--- a/netlink.c
+++ b/netlink.c
@@ -236,67 +236,86 @@ decode_nlmsg_type(const uint16_t type, const unsigned int family)
        decoder(xlat, type, dflt);
 }
 
+static const struct xlat *
+decode_nlmsg_flags_crypto(const uint16_t type)
+{
+       switch (type) {
+       case CRYPTO_MSG_NEWALG:
+               return netlink_new_flags;
+       case CRYPTO_MSG_GETALG:
+               return netlink_get_flags;
+       }
+
+       return NULL;
+}
+
+static const struct xlat *
+decode_nlmsg_flags_route(const uint16_t type)
+{
+       if (type == RTM_DELACTION)
+               return netlink_get_flags;
+       switch (type & 3) {
+       case  0:
+               return netlink_new_flags;
+       case  2:
+               return netlink_get_flags;
+       }
+
+       return NULL;
+}
+
+static const struct xlat *
+decode_nlmsg_flags_sock_diag(const uint16_t type)
+{
+       return netlink_get_flags;
+}
+
+static const struct xlat *
+decode_nlmsg_flags_xfrm(const uint16_t type)
+{
+       switch (type) {
+       case XFRM_MSG_NEWSA:
+       case XFRM_MSG_NEWPOLICY:
+       case XFRM_MSG_NEWAE:
+       case XFRM_MSG_NEWSADINFO:
+       case XFRM_MSG_NEWSPDINFO:
+               return netlink_new_flags;
+       case XFRM_MSG_GETSA:
+       case XFRM_MSG_GETPOLICY:
+       case XFRM_MSG_GETAE:
+       case XFRM_MSG_GETSADINFO:
+       case XFRM_MSG_GETSPDINFO:
+               return netlink_get_flags;
+       }
+
+       return NULL;
+}
+
+typedef const struct xlat *(*nlmsg_flags_decoder_t)(const uint16_t type);
+
+static const nlmsg_flags_decoder_t nlmsg_flags[] = {
+       [NETLINK_CRYPTO] = decode_nlmsg_flags_crypto,
+       [NETLINK_ROUTE] = decode_nlmsg_flags_route,
+       [NETLINK_SOCK_DIAG] = decode_nlmsg_flags_sock_diag,
+       [NETLINK_XFRM] = decode_nlmsg_flags_xfrm
+};
+
+/*
+ * As all valid netlink families are positive integers, use unsigned int
+ * for family here to filter out -1.
+ */
 static void
-decode_nlmsg_flags(const uint16_t flags, const uint16_t type, const int family)
+decode_nlmsg_flags(const uint16_t flags, const uint16_t type,
+                  const unsigned int family)
 {
        const struct xlat *table = NULL;
 
        if (type < NLMSG_MIN_TYPE) {
                if (type == NLMSG_ERROR)
                        table = netlink_ack_flags;
-               goto end;
-       }
-
-       switch (family) {
-       case NETLINK_CRYPTO:
-               switch (type) {
-               case CRYPTO_MSG_NEWALG:
-                       table = netlink_new_flags;
-                       break;
-               case CRYPTO_MSG_GETALG:
-                       table = netlink_get_flags;
-                       break;
-               }
-               break;
-       case NETLINK_SOCK_DIAG:
-               table = netlink_get_flags;
-               break;
-       case NETLINK_ROUTE:
-               if (type == RTM_DELACTION) {
-                       table = netlink_get_flags;
-                       break;
-               }
-               switch (type & 3) {
-               case  0:
-                       table = netlink_new_flags;
-                       break;
-               case  2:
-                       table = netlink_get_flags;
-                       break;
-               }
-               break;
-       case NETLINK_XFRM:
-               switch (type) {
-               case XFRM_MSG_NEWSA:
-               case XFRM_MSG_NEWPOLICY:
-               case XFRM_MSG_NEWAE:
-               case XFRM_MSG_NEWSADINFO:
-               case XFRM_MSG_NEWSPDINFO:
-                       table = netlink_new_flags;
-                       break;
-
-               case XFRM_MSG_GETSA:
-               case XFRM_MSG_GETPOLICY:
-               case XFRM_MSG_GETAE:
-               case XFRM_MSG_GETSADINFO:
-               case XFRM_MSG_GETSPDINFO:
-                       table = netlink_get_flags;
-                       break;
-               }
-               break;
-       }
+       } else if (family < ARRAY_SIZE(nlmsg_flags) && nlmsg_flags[family])
+               table = nlmsg_flags[family](type);
 
-end:
        printflags_ex(flags, "NLM_F_???", netlink_flags, table, NULL);
 }