lib: Add decoder functions

Split existing lua_to* functions into two functions:
 - lua_decode_*: unmarshall Lua values into an existing C data structure
 - lua_to*: allocate *and* unmarshall Lua values into C data structure
This allows us to mutate C data structures passed into frrscript_call,
without allocation

Signed-off-by: Donald Lee <dlqs@gmx.com>

diff --git a/lib/frrlua.c b/lib/frrlua.c
index d8aaa3aa3c6d9abeefff0ad3f966029232e6813d..9fb744cde21f693b0e55aa9c0a51528d1e36b446 100644 (file)
--- a/lib/frrlua.c
+++ b/lib/frrlua.c
@@ -71,14 +71,17 @@ void lua_pushprefix(lua_State *L, const struct prefix *prefix)
        lua_setfield(L, -2, "family");
 }
 
-void *lua_toprefix(lua_State *L, int idx)
+void lua_decode_prefix(lua_State *L, int idx, struct prefix *prefix)
 {
-       struct prefix *p = XCALLOC(MTYPE_TMP, sizeof(struct prefix));
-
        lua_getfield(L, idx, "network");
-       (void)str2prefix(lua_tostring(L, -1), p);
+       (void)str2prefix(lua_tostring(L, -1), prefix);
        lua_pop(L, 1);
+}
 
+void *lua_toprefix(lua_State *L, int idx)
+{
+       struct prefix *p = XCALLOC(MTYPE_TMP, sizeof(struct prefix));
+       lua_decode_prefix(L, idx, p);
        return p;
 }
 
@@ -109,10 +112,8 @@ void lua_pushinterface(lua_State *L, const struct interface *ifp)
        lua_setfield(L, -2, "linklayer_type");
 }
 
-void *lua_tointerface(lua_State *L, int idx)
+void lua_decode_interface(lua_State *L, int idx, struct interface *ifp)
 {
-       struct interface *ifp = XCALLOC(MTYPE_TMP, sizeof(struct interface));
-
        lua_getfield(L, idx, "name");
        strlcpy(ifp->name, lua_tostring(L, -1), sizeof(ifp->name));
        lua_pop(L, 1);
@@ -146,13 +147,19 @@ void *lua_tointerface(lua_State *L, int idx)
        lua_getfield(L, idx, "linklayer_type");
        ifp->ll_type = lua_tointeger(L, -1);
        lua_pop(L, 1);
+}
+void *lua_tointerface(lua_State *L, int idx)
+{
+       struct interface *ifp = XCALLOC(MTYPE_TMP, sizeof(struct interface));
 
+       lua_decode_interface(L, idx, ifp);
        return ifp;
 }
 
 void lua_pushinaddr(lua_State *L, const struct in_addr *addr)
 {
        char buf[INET_ADDRSTRLEN];
+
        inet_ntop(AF_INET, addr, buf, sizeof(buf));
 
        lua_newtable(L);
@@ -162,14 +169,17 @@ void lua_pushinaddr(lua_State *L, const struct in_addr *addr)
        lua_setfield(L, -2, "string");
 }
 
-void *lua_toinaddr(lua_State *L, int idx)
+void lua_decode_inaddr(lua_State *L, int idx, struct in_addr *inaddr)
 {
-       struct in_addr *inaddr = XCALLOC(MTYPE_TMP, sizeof(struct in_addr));
-
        lua_getfield(L, idx, "value");
        inaddr->s_addr = lua_tointeger(L, -1);
        lua_pop(L, 1);
+}
 
+void *lua_toinaddr(lua_State *L, int idx)
+{
+       struct in_addr *inaddr = XCALLOC(MTYPE_TMP, sizeof(struct in_addr));
+       lua_decode_inaddr(L, idx, inaddr);
        return inaddr;
 }
 
@@ -177,6 +187,7 @@ void *lua_toinaddr(lua_State *L, int idx)
 void lua_pushin6addr(lua_State *L, const struct in6_addr *addr)
 {
        char buf[INET6_ADDRSTRLEN];
+
        inet_ntop(AF_INET6, addr, buf, sizeof(buf));
 
        lua_newtable(L);
@@ -186,20 +197,24 @@ void lua_pushin6addr(lua_State *L, const struct in6_addr *addr)
        lua_setfield(L, -2, "string");
 }
 
-void *lua_toin6addr(lua_State *L, int idx)
+void lua_decode_in6addr(lua_State *L, int idx, struct in6_addr *in6addr)
 {
-       struct in6_addr *in6addr = XCALLOC(MTYPE_TMP, sizeof(struct in6_addr));
-
        lua_getfield(L, idx, "string");
        inet_pton(AF_INET6, lua_tostring(L, -1), in6addr);
        lua_pop(L, 1);
+}
 
+void *lua_toin6addr(lua_State *L, int idx)
+{
+       struct in6_addr *in6addr = XCALLOC(MTYPE_TMP, sizeof(struct in6_addr));
+       lua_decode_in6addr(L, idx, in6addr);
        return in6addr;
 }
 
 void lua_pushsockunion(lua_State *L, const union sockunion *su)
 {
        char buf[SU_ADDRSTRLEN];
+
        sockunion2str(su, buf, sizeof(buf));
 
        lua_newtable(L);
@@ -210,13 +225,17 @@ void lua_pushsockunion(lua_State *L, const union sockunion *su)
        lua_setfield(L, -2, "string");
 }
 
-void *lua_tosockunion(lua_State *L, int idx)
+void lua_decode_sockunion(lua_State *L, int idx, union sockunion *su)
 {
-       union sockunion *su = XCALLOC(MTYPE_TMP, sizeof(union sockunion));
-
        lua_getfield(L, idx, "string");
        str2sockunion(lua_tostring(L, -1), su);
+}
+
+void *lua_tosockunion(lua_State *L, int idx)
+{
+       union sockunion *su = XCALLOC(MTYPE_TMP, sizeof(union sockunion));
 
+       lua_decode_sockunion(L, idx, su);
        return su;
 }
 
@@ -225,12 +244,16 @@ void lua_pushtimet(lua_State *L, const time_t *time)
        lua_pushinteger(L, *time);
 }
 
+void lua_decode_timet(lua_State *L, int idx, time_t *t)
+{
+       *t = lua_tointeger(L, idx);
+}
+
 void *lua_totimet(lua_State *L, int idx)
 {
        time_t *t = XCALLOC(MTYPE_TMP, sizeof(time_t));
 
-       *t = lua_tointeger(L, idx);
-
+       lua_decode_timet(L, idx, t);
        return t;
 }
 
@@ -239,17 +262,27 @@ void lua_pushintegerp(lua_State *L, const long long *num)
        lua_pushinteger(L, *num);
 }
 
-void *lua_tointegerp(lua_State *L, int idx)
+void lua_decode_integerp(lua_State *L, int idx, long long *num)
 {
        int isnum;
-       long long *num = XCALLOC(MTYPE_TMP, sizeof(long long));
-
        *num = lua_tonumberx(L, idx, &isnum);
        assert(isnum);
+}
+
+void *lua_tointegerp(lua_State *L, int idx)
+{
+       long long *num = XCALLOC(MTYPE_TMP, sizeof(long long));
 
+       lua_decode_integerp(L, idx, num);
        return num;
 }
 
+void lua_decode_stringp(lua_State *L, int idx, char *str)
+{
+       strlcpy(str, lua_tostring(L, idx), strlen(str) + 1);
+       lua_pop(L, 1);
+}
+
 void *lua_tostringp(lua_State *L, int idx)
 {
        char *string = XSTRDUP(MTYPE_TMP, lua_tostring(L, idx));

diff --git a/lib/frrlua.h b/lib/frrlua.h
index 6fb30938b061d5bedd4cc5328cd90f850bb68f72..3ca5b1f778fb6c6593ad962ad24545115bc66bb9 100644 (file)
--- a/lib/frrlua.h
+++ b/lib/frrlua.h
@@ -50,6 +50,8 @@ static inline void lua_pushstring_wrapper(lua_State *L, const char *str)
  */
 void lua_pushprefix(lua_State *L, const struct prefix *prefix);
 
+void lua_decode_prefix(lua_State *L, int idx, struct prefix *prefix);
+
 /*
  * Converts the Lua value at idx to a prefix.
  *
@@ -63,6 +65,8 @@ void *lua_toprefix(lua_State *L, int idx);
  */
 void lua_pushinterface(lua_State *L, const struct interface *ifp);
 
+void lua_decode_interface(lua_State *L, int idx, struct interface *ifp);
+
 /*
  * Converts the Lua value at idx to an interface.
  *
@@ -77,6 +81,8 @@ void *lua_tointerface(lua_State *L, int idx);
  */
 void lua_pushinaddr(lua_State *L, const struct in_addr *addr);
 
+void lua_decode_inaddr(lua_State *L, int idx, struct in_addr *addr);
+
 /*
  * Converts the Lua value at idx to an in_addr.
  *
@@ -90,6 +96,8 @@ void *lua_toinaddr(lua_State *L, int idx);
  */
 void lua_pushin6addr(lua_State *L, const struct in6_addr *addr);
 
+void lua_decode_in6addr(lua_State *L, int idx, struct in6_addr *addr);
+
 /*
  * Converts the Lua value at idx to an in6_addr.
  *
@@ -103,6 +111,8 @@ void *lua_toin6addr(lua_State *L, int idx);
  */
 void lua_pushtimet(lua_State *L, const time_t *time);
 
+void lua_decode_timet(lua_State *L, int idx, time_t *time);
+
 /*
  * Converts the Lua value at idx to a time_t.
  *
@@ -116,6 +126,8 @@ void *lua_totimet(lua_State *L, int idx);
  */
 void lua_pushsockunion(lua_State *L, const union sockunion *su);
 
+void lua_decode_sockunion(lua_State *L, int idx, union sockunion *su);
+
 /*
  * Converts the Lua value at idx to a sockunion.
  *
@@ -129,6 +141,8 @@ void *lua_tosockunion(lua_State *L, int idx);
  */
 void lua_pushintegerp(lua_State *L, const long long *num);
 
+void lua_decode_integerp(lua_State *L, int idx, long long *num);
+
 /*
  * Converts the Lua value at idx to an int.
  *
@@ -137,6 +151,8 @@ void lua_pushintegerp(lua_State *L, const long long *num);
  */
 void *lua_tointegerp(lua_State *L, int idx);
 
+void lua_decode_stringp(lua_State *L, int idx, char *str);
+
 /*
  * Pop string.
  *

diff --git a/lib/frrscript.h b/lib/frrscript.h
index 5410f53e1167d1c0c87e69d8bff7aa36abbd61a0..14e1834a115f8cc5a8273d4a745f3af4c3f10e2f 100644 (file)
--- a/lib/frrscript.h
+++ b/lib/frrscript.h
@@ -105,7 +105,7 @@ void frrscript_init(const char *scriptdir);
 #define DECODE_ARGS(name, value)                                               \
        do {                                                                   \
                lua_getglobal(L, name);                                        \
-               DECODE_ARGS_WITH_STATE(L, value)                               \
+               DECODE_ARGS_WITH_STATE(L, value);                              \
        } while (0)
 
 #define ENCODE_ARGS_WITH_STATE(L, value)                                       \
@@ -120,7 +120,17 @@ time_t * : lua_pushtimet,                                       \
 char * : lua_pushstring_wrapper                                 \
 )(L, value)
 
-#define DECODE_ARGS_WITH_STATE(L, value) _Generic((value), )(L, value);
+#define DECODE_ARGS_WITH_STATE(L, value)                                       \
+       _Generic((value), \
+long long * : lua_decode_integerp,                              \
+struct prefix * : lua_decode_prefix,                            \
+struct interface * : lua_decode_interface,                      \
+struct in_addr * : lua_decode_inaddr,                           \
+struct in6_addr * : lua_decode_in6addr,                         \
+union sockunion * : lua_decode_sockunion,                       \
+time_t * : lua_decode_timet,                                    \
+char * : lua_decode_stringp                                     \
+)(L, -1, value)
 
 /*
  * Call script.