X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Finternal.h;h=29f4dd23e7735c077ee8f02323f4e5ab8f95bf3f;hb=7f5937118639156f1fb201c42298c00e1f54c3cc;hp=58cd15d2fba69ae80e8f09bf99b71580b8cce07a;hpb=ae8cc9775a6eb23901a89a2604f73525b0553db8;p=adns.git

diff --git a/src/internal.h b/src/internal.h
index 58cd15d..29f4dd2 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -72,6 +72,27 @@ typedef unsigned char byte;
 
 #define MAX_POLLFDS  ADNS_POLLFDS_RECOMMENDED
 
+/* Some preprocessor hackery */
+
+#define GLUE(x, y) GLUE_(x, y)
+#define GLUE_(x, y) x##y
+
+/* C99 macro `...' must match at least one argument, so the naive definition
+ * `#define CAR(car, ...) car' won't work.  But it's easy to arrange for the
+ * tail to be nonempty if we're just going to discard it anyway. */
+#define CAR(...) CAR_(__VA_ARGS__, _)
+#define CAR_(car, ...) car
+
+/* Extracting the tail of an argument list is rather more difficult.  The
+ * following trick is based on one by Laurent Deniau to count the number of
+ * arguments to a macro, simplified in two ways: (a) it only handles up to
+ * eight arguments, and (b) it only needs to distinguish the one-argument
+ * case from many arguments. */
+#define CDR(...) CDR_(__VA_ARGS__, m, m, m, m, m, m, m, 1, _)(__VA_ARGS__)
+#define CDR_(_1, _2, _3, _4, _5, _6, _7, _8, n, ...) CDR_##n
+#define CDR_1(_)
+#define CDR_m(_, ...) __VA_ARGS__
+
 typedef enum {
   cc_user,
   cc_entex,
@@ -89,15 +110,6 @@ typedef enum {
 
 /* Shared data structures */
 
-typedef union {
-  adns_status status;
-  char *cp;
-  adns_rrtype type;
-  int i;
-  struct in_addr ia;
-  unsigned long ul;
-} rr_align;
-
 typedef struct {
   int used, avail;
   byte *buf;
@@ -112,6 +124,26 @@ typedef struct {
   struct timeval now;
 } parseinfo;
 
+union checklabel_state {
+  struct { byte ipv[4]; } ptr;
+};
+
+typedef struct {
+  void *ext;
+  void (*callback)(adns_query parent, adns_query child);
+
+  union {
+    struct {
+      struct in_addr addr;
+    } ptr;
+  } tinfo; /* type-specific state for the query itself: zero-init if you
+	    * don't know better. */
+
+  union {
+    adns_rr_hostaddr *hostaddr;
+  } pinfo; /* state for use by parent's callback function */
+} qcontext;
+
 typedef struct typeinfo {
   adns_rrtype typekey;
   const char *rrtname;
@@ -147,16 +179,17 @@ typedef struct typeinfo {
    * 0 otherwise.  Must not fail.
    */
 
-  adns_status (*qdparselabel)(adns_state ads,
-			      const char **p_io, const char *pe, int labelnum,
-			      char label_r[DNS_MAXDOMAIN], int *ll_io,
-			      adns_queryflags flags,
-			      const struct typeinfo *typei);
-  /* Parses one label from the query domain string.  On entry, *p_io
-   * points to the next character to parse and *ll_io is the size of
-   * the buffer.  pe points just after the end of the query domain
-   * string.  On successful return, label_r[] and *ll_io are filled in
-   * and *p_io points to *pe or just after the label-ending `.'.  */
+  adns_status (*checklabel)(adns_state ads, adns_queryflags flags,
+			    union checklabel_state *cls, qcontext *ctx,
+			    int labnum, const char *label, int lablen);
+  /* Check a label from the query domain string.  The label is not
+   * necessarily null-terminated.  The hook can refuse the query's submission
+   * by returning a nonzero status.  State can be stored in *cls between
+   * calls, and useful information can be stashed in ctx->tinfo, to be stored
+   * with the query (e.g., it will be available to the parse hook).  This
+   * hook can detect a first call because labnum is zero, and a final call
+   * because lablen is zero.
+   */
 
   void (*postsort)(adns_state ads, void *array, int nrrs,
 		   const struct typeinfo *typei);
@@ -166,13 +199,13 @@ typedef struct typeinfo {
    */
 } typeinfo;
 
-adns_status adns__qdpl_normal(adns_state ads,
-			      const char **p_io, const char *pe, int labelnum,
-			      char label_r[], int *ll_io,
-			      adns_queryflags flags,
-			      const typeinfo *typei);
-  /* implemented in transmit.c, used by types.c as default
-   * and as part of implementation for some fancier types */
+adns_status adns__ckl_hostname(adns_state ads, adns_queryflags flags,
+			       union checklabel_state *cls,
+			       qcontext *ctx, int labnum,
+			       const char *label, int lablen);
+  /* implemented in query.c, used by types.c as default
+   * and as part of implementation for some fancier types
+   * doesn't require any state */
 
 typedef struct allocnode {
   struct allocnode *next, *back;
@@ -187,15 +220,6 @@ union maxalign {
   union maxalign *up;
 } data;
 
-typedef struct {
-  void *ext;
-  void (*callback)(adns_query parent, adns_query child);
-  union {
-    adns_rr_addr ptr_parent_addr;
-    adns_rr_hostaddr *hostaddr;
-  } info;
-} qcontext;
-
 struct adns__query {
   adns_state ads;
   enum { query_tosend, query_tcpw, query_childw, query_done } state;
@@ -435,10 +459,10 @@ void adns__query_send(adns_query qu, struct timeval now);
 /* From query.c: */
 
 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
-				  const typeinfo *typei, vbuf *qumsg_vb,
-				  int id,
+				  const typeinfo *typei, adns_rrtype type,
+				  vbuf *qumsg_vb, int id,
 				  adns_queryflags flags, struct timeval now,
-				  const qcontext *ctx);
+				  qcontext *ctx);
 /* Submits a query (for internal use, called during external submits).
  *
  * The new query is returned in *query_r, or we return adns_s_nomemory.
@@ -447,7 +471,8 @@ adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
  * the memory for it is _taken over_ by this routine whether it
  * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
  *
- * *ctx is copied byte-for-byte into the query.
+ * *ctx is copied byte-for-byte into the query.  Before doing this, its tinfo
+ * field may be modified by type hooks.
  *
  * When the child query is done, ctx->callback will be called.  The
  * child will already have been taken off both the global list of