X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Finternal.h;h=7ee8671fbc2967f2b3575e22a4e405602d3c2aca;hb=d8c062faeda8147546f1e709171f7f0767331954;hp=5e42adeb0cc963a2a5bb6606f22d73417386ac2d;hpb=eaa4473118b245a9dc1d806309eb70d4b2c6eaa4;p=adns.git

diff --git a/src/internal.h b/src/internal.h
index 5e42ade..7ee8671 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -31,6 +31,8 @@ typedef unsigned char byte;
 #include <stdarg.h>
 #include <assert.h>
 #include <unistd.h>
+#include <signal.h>
+#include <errno.h>
 
 #include <sys/time.h>
 
@@ -43,17 +45,19 @@ typedef unsigned char byte;
 #define UDPMAXRETRIES 15
 #define UDPRETRYMS 2000
 #define TCPMS 30000
-#define LOCALRESOURCEMS 20
 #define MAXTTLBELIEVE (7*86400) /* any TTL > 7 days is capped */
 
 #define DNS_PORT 53
 #define DNS_MAXUDP 512
 #define DNS_MAXDOMAIN 255
 #define DNS_HDRSIZE 12
+#define DNS_IDOFFSET 0
 #define DNS_CLASS_IN 1
 
 #define DNS_INADDR_ARPA "in-addr", "arpa"
 
+#define MAX_POLLFDS  ADNS_POLLFDS_RECOMMENDED
+
 typedef enum {
   rcode_noerror,
   rcode_formaterror,
@@ -147,14 +151,14 @@ typedef struct {
 
 struct adns__query {
   adns_state ads;
-  enum { query_udp, query_tcpwait, query_tcpsent, query_child, query_done } state;
+  enum { query_tosend, query_tcpwait, query_tcpsent, query_child, query_done } state;
   adns_query back, next, parent;
   struct { adns_query head, tail; } children;
   struct { adns_query back, next; } siblings;
   struct { allocnode *head, *tail; } allocations;
-  int interim_allocd;
+  int interim_allocd, preserved_allocd;
   void *final_allocspace;
-  
+
   const typeinfo *typei;
   byte *query_dgram;
   int query_dglen;
@@ -172,11 +176,24 @@ struct adns__query {
    * we found a cname (this corresponds to cname_dgram in the query
    * structure).  type is set from the word go.  nrrs and rrs
    * are set together, when we find how many rrs there are.
+   * owner is set during querying unless we're doing searchlist,
+   * in which case it is set only when we find an answer.
    */
   
   byte *cname_dgram;
   int cname_dglen, cname_begin;
   /* If non-0, has been allocated using . */
+
+  vbuf search_vb;
+  int search_origlen, search_pos, search_doneabs;
+  /* Used by the searching algorithm.  The query domain in textual form
+   * is copied into the vbuf, and _origlen set to its length.  Then
+   * we walk the searchlist, if we want to.  _pos says where we are
+   * (next entry to try), and _doneabs says whether we've done the
+   * absolute query yet (0=not yet, 1=done, -1=must do straight away,
+   * but not done yet).  If flags doesn't have adns_qf_search then
+   * the vbuf is initialised but empty and everything else is zero.
+   */
   
   int id, flags, udpretries;
   int udpnextserver;
@@ -190,16 +207,19 @@ struct adns__query {
    *
    *  state   Queue   child  id   nextudpserver  sentudp     failedtcp
    *				  
-   *  udp     NONE    null   >=0  0              zero        zero
-   *  udp     timew   null   >=0  any            nonzero     zero
-   *  udp     NONE    null   >=0  any            nonzero     zero
+   *  tosend  NONE    null   >=0  0              zero        zero
+   *  tosend  timew   null   >=0  any            nonzero     zero
+   *  tosend  NONE    null   >=0  any            nonzero     zero
    *				  
    *  tcpwait timew   null   >=0  irrelevant     zero        any
    *  tcpsent timew   null   >=0  irrelevant     zero        any
    *				  
    *  child   childw  set    >=0  irrelevant     irrelevant  irrelevant
+   *  child   NONE    null   >=0  irrelevant     irrelevant  irrelevant
    *  done    output  null   -1   irrelevant     irrelevant  irrelevant
    *
+   * Queries are only not on a queue when they are actually being processed.
+   *
    *			      +------------------------+
    *             START -----> |      udp/NONE          |
    *			      +------------------------+
@@ -244,22 +264,28 @@ struct adns__state {
   FILE *diagfile;
   int configerrno;
   struct { adns_query head, tail; } timew, childw, output;
+  adns_query forallnext;
   int nextid, udpsocket, tcpsocket;
   vbuf tcpsend, tcprecv;
-  int nservers, nsortlist, tcpserver;
+  int nservers, nsortlist, nsearchlist, searchndots, tcpserver;
   enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
   struct timeval tcptimeout;
+  struct sigaction stdsigpipe;
+  sigset_t stdsigmask;
+  struct pollfd pollfds_buf[MAX_POLLFDS];
   struct server {
     struct in_addr addr;
   } servers[MAXSERVERS];
   struct sortlist {
     struct in_addr base, mask;
   } sortlist[MAXSORTLIST];
+  char **searchlist;
 };
 
 /* From setup.c: */
 
 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
+void adns__checkqueues(adns_state ads); /* expensive walk, for checking */
 
 /* From general.c: */
 
@@ -302,13 +328,22 @@ void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
  * sz bytes long.  needswap should return !0 if a>b (strictly, ie
  * wrong order) 0 if a<=b (ie, order is fine).
  */
-  
+
+void adns__sigpipe_protect(adns_state);
+void adns__sigpipe_unprotect(adns_state);
+/* If SIGPIPE protection is not disabled, will block all signals except
+ * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN.  (And then restore.)
+ * Each call to _protect must be followed by a call to _unprotect before
+ * any significant amount of code gets to run.
+ */
+
 /* From transmit.c: */
 
 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
 			  const char *owner, int ol,
 			  const typeinfo *typei, adns_queryflags flags);
-/* Assembles a query packet in vb, and returns id at *id_r. */
+/* Assembles a query packet in vb.  A new id is allocated and returned.
+ */
 
 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
 				  const byte *qd_dgram, int qd_dglen, int qd_begin,
@@ -329,19 +364,22 @@ void adns__query_tcp(adns_query qu, struct timeval now);
  * reestablishment and retry.
  */
 
-void adns__query_udp(adns_query qu, struct timeval now);
-/* Query must be in state udp/NONE; it will be moved to a new state,
+void adns__query_send(adns_query qu, struct timeval now);
+/* Query must be in state tosend/NONE; it will be moved to a new state,
  * and no further processing can be done on it for now.
  * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
  *  tcpsent/timew, child/childw or done/output.)
+ * __query_send may decide to use either UDP or TCP depending whether
+ * _qf_usevc is set (or has become set) and whether the query is too
+ * large.
  */
 
 /* From query.c: */
 
-int adns__internal_submit(adns_state ads, adns_query *query_r,
-			  const typeinfo *typei, vbuf *qumsg_vb, int id,
-			  adns_queryflags flags, struct timeval now,
-			  adns_status failstat, const qcontext *ctx);
+adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
+				  const typeinfo *typei, vbuf *qumsg_vb, int id,
+				  adns_queryflags flags, struct timeval now,
+				  const 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.
@@ -350,27 +388,54 @@ int 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).
  *
- * If failstat is nonzero then if we are successful in creating the query
- * it is immediately failed with code failstat (but _submit still succeds).
- *
  * *ctx is copied byte-for-byte into the query.
+ *
+ * When the child query is done, ctx->callback will be called.  The
+ * child will already have been taken off both the global list of
+ * queries in ads and the list of children in the parent.  The child
+ * will be freed when the callback returns.  The parent will have been
+ * taken off the global childw queue.
+ *
+ * The callback should either call adns__query_done, if it is
+ * complete, or adns__query_fail, if an error has occurred, in which
+ * case the other children (if any) will be cancelled.  If the parent
+ * has more unfinished children (or has just submitted more) then the
+ * callback may choose to wait for them - it must then put the parent
+ * back on the childw queue.
+ */
+
+void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
+/* Walks down the searchlist for a query with adns_qf_search.
+ * The query should have just had a negative response, or not had
+ * any queries sent yet, and should not be on any queue.
+ * The query_dgram if any will be freed and forgotten and a new
+ * one constructed from the search_* members of the query.
+ *
+ * Cannot fail (in case of error, calls adns__query_fail).
  */
 
 void *adns__alloc_interim(adns_query qu, size_t sz);
+void *adns__alloc_preserved(adns_query qu, size_t sz);
 /* Allocates some memory, and records which query it came from
  * and how much there was.
  *
- * If an error occurs in the query, all its memory is simply freed.
- *
- * If the query succeeds, one large buffer will be made which is
- * big enough for all these allocations, and then adns__alloc_final
- * will get memory from this buffer.
+ * If an error occurs in the query, all the memory from _interim is
+ * simply freed.  If the query succeeds, one large buffer will be made
+ * which is big enough for all these allocations, and then
+ * adns__alloc_final will get memory from this buffer.
  *
  * _alloc_interim can fail (and return 0).
  * The caller must ensure that the query is failed.
  *
- * adns__alloc_interim_{only,fail}(qu,0) will not return 0,
- * but it will not necessarily return a distinct pointer each time.
+ * The memory from _preserved is is kept and transferred into the
+ * larger buffer - unless we run out of memory, in which case it too
+ * is freed.  When you use _preserved you have to add code to the
+ * x_nomem error exit case in adns__makefinal_query to clear out the
+ * pointers you made to those allocations, because that's when they're
+ * thrown away; you should also make a note in the declaration of
+ * those pointer variables, to note that they are _preserved rather
+ * than _interim.  If they're in the answer, note it here:
+ *  answer->cname and answer->owner are _preserved.
  */
 
 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz);
@@ -400,12 +465,12 @@ void *adns__alloc_final(adns_query qu, size_t sz);
 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
 void adns__makefinal_str(adns_query qu, char **strp);
 
-void adns__reset_cnameonly(adns_query qu);
-/* Resets all of the memory management stuff etc. to
- * take account of only the CNAME.  Used when we find an error somewhere
- * and want to just report the error (with perhaps CNAME info), and also
- * when we're halfway through RRs in a datagram and discover that we
- * need to retry the query.
+void adns__reset_preserved(adns_query qu);
+/* Resets all of the memory management stuff etc. to take account of
+ * only the _preserved stuff from _alloc_preserved.  Used when we find
+ * an error somewhere and want to just report the error (with perhaps
+ * CNAME, owner, etc. info), and also when we're halfway through RRs
+ * in a datagram and discover that we need to retry the query.
  */
 
 void adns__query_done(adns_query qu);
@@ -550,11 +615,24 @@ int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
 /* From event.c: */
 
 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
+void adns__tcp_closenext(adns_state ads);
 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
 
 void adns__autosys(adns_state ads, struct timeval now);
 /* Make all the system calls we want to if the application wants us to. */
 
+void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
+			     struct timeval *tv_buf);
+void adns__timeouts(adns_state ads, int act,
+		    struct timeval **tv_io, struct timeval *tvbuf,
+		    struct timeval now);
+int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
+void adns__fdevents(adns_state ads,
+		    const struct pollfd *pollfds, int npollfds,
+		    int maxfd, const fd_set *readfds,
+		    const fd_set *writefds, const fd_set *exceptfds,
+		    struct timeval now, int *r_r);
+
 /* Useful static inline functions: */
 
 static inline void timevaladd(struct timeval *tv_io, long ms) {
@@ -570,9 +648,11 @@ static inline void timevaladd(struct timeval *tv_io, long ms) {
 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
 static inline int ctype_alpha(int c) {
-  return (c >= 'a' && c <= 'z') || (c >= 'A' || c <= 'Z');
+  return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
 }
 
+static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
+
 /* Useful macros */
 
 #define MEM_ROUND(sz) \
@@ -580,6 +660,7 @@ static inline int ctype_alpha(int c) {
    * sizeof(union maxalign) )
 
 #define LIST_INIT(list) ((list).head= (list).tail= 0)
+#define LINK_INIT(link) ((link).next= (link).back= 0)
 
 #define LIST_UNLINK_PART(list,node,part) \
   do { \