netlink: refactor decode_nlmsg_type

* netlink.c (decode_nlmsg_type_default, decode_nlmsg_type_netfilter):
New functions.
(nlmsg_types_decoder_t): New typedef.
(nlmsg_types): Add decoder field.
(decode_nlmsg_type): Use it.

diff --git a/netlink.c b/netlink.c
index 049843de1482c03e8f58a8207b12a41eda20fed7..06144d5048f9745107d1a603b3bb41d4d96bfaf9 100644 (file)
--- a/netlink.c
+++ b/netlink.c
@@ -100,16 +100,61 @@ get_fd_nl_family(struct tcb *const tcp, const int fd)
        return NL_FAMILY_ERROR;
 }
 
+static void
+decode_nlmsg_type_default(const struct xlat *const xlat,
+                         const uint16_t type,
+                         const char *const dflt)
+{
+       printxval(xlat, type, dflt);
+}
+
+static void
+decode_nlmsg_type_netfilter(const struct xlat *const xlat,
+                           const uint16_t type,
+                           const char *const dflt)
+{
+       /* Reserved control nfnetlink messages first. */
+       const char *const text = xlookup(nl_netfilter_msg_types, type);
+       if (text) {
+               tprints(text);
+               return;
+       }
+
+       /*
+        * Other netfilter message types are split
+        * in two pieces: 8 bits subsystem and 8 bits type.
+        */
+       const uint8_t subsys_id = (uint8_t) (type >> 8);
+       const uint8_t msg_type = (uint8_t) type;
+
+       printxval(xlat, subsys_id, dflt);
+
+       /*
+        * The type is subsystem specific,
+        * print it in numeric format for now.
+        */
+       tprintf("<<8|%#x", msg_type);
+}
+
+typedef void (*nlmsg_types_decoder_t)(const struct xlat *,
+                                     uint16_t type,
+                                     const char *dflt);
+
 static const struct {
+       const nlmsg_types_decoder_t decoder;
        const struct xlat *const xlat;
        const char *const dflt;
 } nlmsg_types[] = {
-       [NETLINK_AUDIT] = { nl_audit_types, "AUDIT_???" },
-       [NETLINK_NETFILTER] = { nl_netfilter_subsys_ids, "NFNL_SUBSYS_???" },
-       [NETLINK_ROUTE] = { nl_route_types, "RTM_???" },
-       [NETLINK_SELINUX] = { nl_selinux_types, "SELNL_MSG_???" },
-       [NETLINK_SOCK_DIAG] = { nl_sock_diag_types, "SOCK_DIAG_???" },
-       [NETLINK_XFRM] = { nl_xfrm_types, "XFRM_MSG_???" }
+       [NETLINK_AUDIT] = { NULL, nl_audit_types, "AUDIT_???" },
+       [NETLINK_NETFILTER] = {
+               decode_nlmsg_type_netfilter,
+               nl_netfilter_subsys_ids,
+               "NFNL_SUBSYS_???"
+       },
+       [NETLINK_ROUTE] = { NULL, nl_route_types, "RTM_???" },
+       [NETLINK_SELINUX] = { NULL, nl_selinux_types, "SELNL_MSG_???" },
+       [NETLINK_SOCK_DIAG] = { NULL, nl_sock_diag_types, "SOCK_DIAG_???" },
+       [NETLINK_XFRM] = { NULL, nl_xfrm_types, "XFRM_MSG_???" }
 };
 
 /*
@@ -119,39 +164,20 @@ static const struct {
 static void
 decode_nlmsg_type(const uint16_t type, const unsigned int family)
 {
-       if (family < ARRAY_SIZE(nlmsg_types)
-           && nlmsg_types[family].xlat) {
-               if (family == NETLINK_NETFILTER) {
-                       /* Reserved control nfnetlink messages first. */
-                       const char *text = xlookup(nl_netfilter_msg_types,
-                                                  type);
-                       if (text) {
-                               tprints(text);
-                               return;
-                       }
-
-                       /*
-                        * Other netfilter message types are split
-                        * in two pieces: 8 bits subsystem and 8 bits type.
-                        */
-                       const uint8_t subsys_id = (uint8_t) (type >> 8);
-                       const uint8_t msg_type = (uint8_t) type;
-
-                       printxval(nlmsg_types[family].xlat, subsys_id,
-                                 nlmsg_types[family].dflt);
-
-                       /*
-                        * The type is subsystem specific,
-                        * print it in numeric format for now.
-                        */
-                       tprintf("<<8|%#x", msg_type);
-               } else {
-                       printxval(nlmsg_types[family].xlat, type,
-                                 nlmsg_types[family].dflt);
-               }
-       } else {
-               printxval(netlink_types, type, "NLMSG_???");
+       nlmsg_types_decoder_t decoder = decode_nlmsg_type_default;
+       const struct xlat *xlat = netlink_types;
+       const char *dflt = "NLMSG_???";
+
+       if (family < ARRAY_SIZE(nlmsg_types)) {
+               if (nlmsg_types[family].decoder)
+                       decoder = nlmsg_types[family].decoder;
+               if (nlmsg_types[family].xlat)
+                       xlat = nlmsg_types[family].xlat;
+               if (nlmsg_types[family].dflt)
+                       dflt = nlmsg_types[family].dflt;
        }
+
+       decoder(xlat, type, dflt);
 }
 
 static void