* - comments regarding library data structures
*/
/*
- * This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson
+ * This file is
+ * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
+ *
+ * It is part of adns, which is
+ * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
+ * Copyright (C) 1999 Tony Finch <dot@dotat.at>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
#include <assert.h>
#include <unistd.h>
#include <signal.h>
+#include <errno.h>
+#include <string.h>
#include <sys/time.h>
#include "adns.h"
+#include "dlist.h"
/* Configuration and constants */
#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 {
+ cc_user,
+ cc_entex,
+ cc_freq
+} consistency_checks;
+
typedef enum {
rcode_noerror,
rcode_formaterror,
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;
* 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;
/* Possible states:
*
- * state Queue child id nextudpserver sentudp failedtcp
+ * state Queue child id nextudpserver udpsent tcpfailed
*
- * 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
+ * tcpwait timew null >=0 irrelevant any any
+ * tcpsent timew null >=0 irrelevant any 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 |
* +------------------------+
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, tcprecv_skip;
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: */
/* 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.
+ * any significant amount of code gets to run, since the old signal mask
+ * is stored in the adns structure.
*/
/* 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,
*
* adns__tcp_tryconnect should already have been called - _tcp
* will only use an existing connection (if there is one), which it
- * may break. If the conn list lost then the caller is responsible for any
+ * may break. If the conn is lost then the caller is responsible for any
* 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.
* 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);
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);
/* From reply.c: */
void adns__procdgram(adns_state ads, const byte *dgram, int len,
- int serv, struct timeval now);
+ int serv, int viatcp, struct timeval now);
+/* This function is allowed to cause new datagrams to be constructed
+ * and sent, or even new queries to be started. However,
+ * query-sending functions are not allowed to call any general event
+ * loop functions in case they accidentally call this.
+ */
/* From types.c: */
/* 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. */
+/* Make all the system calls we want to if the application wants us to.
+ * Must not be called from within adns internal processing functions,
+ * lest we end up in recursive descent !
+ */
+
+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);
+int adns__internal_check(adns_state ads,
+ adns_query *query_io,
+ adns_answer **answer,
+ void **context_r);
+
+/* From check.c: */
+
+void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
/* Useful static inline functions: */
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 ctype_822special(int c) { return strchr("()<>@,;:\\\".[]",c) != 0; }
+
+static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
/* Useful macros */
(( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
* sizeof(union maxalign) )
-#define LIST_INIT(list) ((list).head= (list).tail= 0)
-
-#define LIST_UNLINK_PART(list,node,part) \
- do { \
- if ((node)->part back) (node)->part back->part next= (node)->part next; \
- else (list).head= (node)->part next; \
- if ((node)->part next) (node)->part next->part back= (node)->part back; \
- else (list).tail= (node)->part back; \
- } while(0)
-
-#define LIST_LINK_TAIL_PART(list,node,part) \
- do { \
- (node)->part next= 0; \
- (node)->part back= (list).tail; \
- if ((list).tail) (list).tail->part next= (node); else (list).head= (node); \
- (list).tail= (node); \
- } while(0)
-
-#define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
-#define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
-
#define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
#define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
#define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
~ianmdlvl / adns.git / blobdiff