* - comments regarding library data structures
*/
/*
- * 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 file is part of adns, which is
+ * Copyright (C) 1997-2000,2003,2006 Ian Jackson
+ * Copyright (C) 1999-2000,2003,2006 Tony Finch
+ * Copyright (C) 1991 Massachusetts Institute of Technology
+ * (See the file INSTALL for full details.)
*
* 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 <signal.h>
#include <errno.h>
#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
#include <sys/time.h>
+#define ADNS_FEATURE_MANYAF
#include "adns.h"
#include "dlist.h"
+#ifdef ADNS_REGRESS_TEST
+# include "hredirect.h"
+#endif
+
/* Configuration and constants */
#define MAXSERVERS 5
#define DNS_PORT 53
#define DNS_MAXUDP 512
+#define DNS_MAXLABEL 63
#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
+/* 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,
rcode_refused
} dns_rcode;
-/* Shared data structures */
+enum {
+ adns__qf_addr_answer= 0x01000000,/* addr query received an answer */
+ adns__qf_addr_cname = 0x02000000 /* addr subquery performed on cname */
+};
-typedef union {
- adns_status status;
- char *cp;
- adns_rrtype type;
- int i;
- struct in_addr ia;
- unsigned long ul;
-} rr_align;
+/* Shared data structures */
typedef struct {
int used, avail;
struct timeval now;
} parseinfo;
+#define MAXREVLABELS 34 /* keep in sync with addrfam! */
+struct revparse_state {
+ uint16_t labstart[MAXREVLABELS];
+ uint8_t lablen[MAXREVLABELS];
+};
+
+union checklabel_state {
+ struct revparse_state ptr;
+};
+
typedef struct {
- adns_rrtype type;
+ void *ext;
+ void (*callback)(adns_query parent, adns_query child);
+
+ union {
+ struct {
+ adns_rrtype rev_rrtype;
+ adns_sockaddr addr;
+ } ptr;
+ struct {
+ unsigned want, have;
+ } addr;
+ } 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;
const char *fmtname;
- int rrsz;
+ int fixed_rrsz;
void (*makefinal)(adns_query qu, void *data);
/* Change memory management of *data.
* and will not be null-terminated by convstring.
*/
- adns_status (*parse)(const parseinfo *pai, int cbyte, int max, void *store_r);
+ adns_status (*parse)(const parseinfo *pai, int cbyte,
+ int max, void *store_r);
/* Parse one RR, in dgram of length dglen, starting at cbyte and
* extending until at most max.
*
- * The RR should be stored at *store_r, of length qu->typei->rrsz.
+ * The RR should be stored at *store_r, of length qu->typei->getrrsz().
*
* If there is an overrun which might indicate truncation, it should set
* *rdstart to -1; otherwise it may set it to anything else positive.
* nsstart is the offset of the authority section.
*/
- int (*diff_needswap)(adns_state ads, const void *datap_a, const void *datap_b);
+ int (*diff_needswap)(adns_state ads,const void *datap_a,const void *datap_b);
/* Returns !0 if RR a should be strictly after RR b in the sort order,
* 0 otherwise. Must not fail.
*/
+
+ adns_status (*checklabel)(adns_state ads, adns_queryflags flags,
+ union checklabel_state *cls, qcontext *ctx,
+ int labnum, const char *dgram,
+ int labstart, 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, int rrsz,
+ const struct typeinfo *typei);
+ /* Called immediately after the RRs have been sorted, and may rearrange
+ * them. (This is really for the benefit of SRV's bizarre weighting
+ * stuff.) May be 0 to mean nothing needs to be done.
+ */
+
+ int (*getrrsz)(const struct typeinfo *typei, adns_rrtype type);
+ /* Return the output resource-record element size; if this is null, then
+ * the rrsz member can be used.
+ */
+
+ void (*query_send)(adns_query qu, struct timeval now);
+ /* Send the query to nameservers, and hook it into the appropriate queue.
+ * Normal behaviour is to call adns__query_send, but this can be overridden
+ * for special effects.
+ */
} typeinfo;
+adns_status adns__ckl_hostname(adns_state ads, adns_queryflags flags,
+ union checklabel_state *cls,
+ qcontext *ctx, int labnum,
+ const char *dgram, int labstart, 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;
+ size_t sz;
} allocnode;
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;
* Queries in state tcpw/tcpw have been sent (or are in the to-send buffer)
* iff the tcp connection is in state server_ok.
*
+ * Internal queries (from adns__submit_internal) end up on intdone
+ * instead of output, and the callbacks are made on the way out of
+ * adns, to avoid reentrancy hazards.
+ *
* +------------------------+
* START -----> | tosend/NONE |
* +------------------------+
struct query_queue { adns_query head, tail; };
+#define MAXUDP 2
+
struct adns__state {
adns_initflags iflags;
- FILE *diagfile;
+ adns_logcallbackfn *logfn;
+ void *logfndata;
int configerrno;
- struct query_queue udpw, tcpw, childw, output;
+ struct query_queue udpw, tcpw, childw, output, intdone;
adns_query forallnext;
- int nextid, udpsocket, tcpsocket;
+ int nextid, tcpsocket;
+ struct udpsocket { int af; int fd; } udpsocket[MAXUDP];
+ int nudp;
vbuf tcpsend, tcprecv;
int nservers, nsortlist, nsearchlist, searchndots, tcpserver, tcprecv_skip;
enum adns__tcpstate {
server_ok, server_broken
} tcpstate;
struct timeval tcptimeout;
- /* This will have tv_sec==0 if it is not valid.
- * It will always be valid if tcpstate _connecting.
- * When _ok, it will be nonzero if we are idle
- * (ie, tcpw queue is empty) and counting down.
+ /* This will have tv_sec==0 if it is not valid. It will always be
+ * valid if tcpstate _connecting. When _ok, it will be nonzero if
+ * we are idle (ie, tcpw queue is empty), in which case it is the
+ * absolute time when we will close the connection.
*/
struct sigaction stdsigpipe;
sigset_t stdsigmask;
struct pollfd pollfds_buf[MAX_POLLFDS];
- struct server {
- struct in_addr addr;
- } servers[MAXSERVERS];
+ adns_rr_addr servers[MAXSERVERS];
struct sortlist {
- struct in_addr base, mask;
+ adns_sockaddr base, mask;
} sortlist[MAXSORTLIST];
char **searchlist;
+ unsigned short rand48xsubi[3];
};
+/* From addrfam.c: */
+
+extern int adns__addrs_equal_raw(const struct sockaddr *a,
+ int bf, const void *b);
+/* Returns nonzero a's family is bf and a's protocol address field
+ * refers to the same protocol address as that stored at ba.
+ */
+
+extern int adns__addrs_equal(const adns_sockaddr *a,
+ const adns_sockaddr *b);
+/* Returns nonzero if the two refer to the same protocol address
+ * (disregarding port, IPv6 scope, etc).
+ */
+
+extern int adns__sockaddrs_equal(const struct sockaddr *sa,
+ const struct sockaddr *sb);
+/* Return nonzero if the two socket addresses are equal (in all significant
+ * respects).
+ */
+
+extern int adns__addr_width(int af);
+/* Return the width of addresses of family af, in bits. */
+
+extern void adns__prefix_mask(adns_sockaddr *sa, int len);
+/* Stores in sa's protocol address field an address mask for address
+ * family af, whose first len bits are set and the remainder are
+ * clear. On entry, sa's af field must be set. This is what you want
+ * for converting a prefix length into a netmask.
+ */
+
+extern int adns__guess_prefix_length(const adns_sockaddr *addr);
+/* Given a network base address, guess the appropriate prefix length based on
+ * the appropriate rules for the address family (e.g., for IPv4, this uses
+ * the old address classes).
+ */
+
+extern int adns__addr_matches(int af, const void *addr,
+ const adns_sockaddr *base,
+ const adns_sockaddr *mask);
+/* Return nonzero if the protocol address specified by af and addr
+ * lies within the network specified by base and mask.
+ */
+
+extern void adns__addr_inject(const void *a, adns_sockaddr *sa);
+/* Injects the protocol address *a into the socket adress sa. Assumes
+ * that sa->sa_family is already set correctly.
+ */
+
+extern const void *adns__sockaddr_addr(const struct sockaddr *sa);
+/* Returns the address of the protocol address field in sa.
+ */
+
+char *adns__sockaddr_ntoa(const struct sockaddr *sa, char *buf);
+/* Convert sa to a string, and write it to buf, which must be at least
+ * ADNS_ADDR2TEXT_BUFLEN bytes long (unchecked). Return buf; can't fail.
+ */
+
+extern int adns__make_reverse_domain(const struct sockaddr *sa,
+ const char *zone,
+ char **buf_io, size_t bufsz,
+ char **buf_free_r);
+/* Construct a reverse domain string, given a socket address and a parent
+ * zone. If zone is null, then use the standard reverse-lookup zone for the
+ * address family. If the length of the resulting string is no larger than
+ * bufsz, then the result is stored starting at *buf_io; otherwise a new
+ * buffer is allocated is used, and a pointer to it is stored in both *buf_io
+ * and *buf_free_r (the latter of which should be null on entry). If
+ * something goes wrong, then an errno value is returned: ENOSYS if the
+ * address family of sa isn't recognized, or ENOMEM if the attempt to
+ * allocate an output buffer failed.
+ */
+
+extern bool adns__revparse_label(struct revparse_state *rps, int labnum,
+ const char *dgram,
+ int labstart, int lablen);
+/* Parse a label in a reverse-domain name, given its index labnum (starting
+ * from zero), a pointer to its contents (which need not be null-terminated),
+ * and its length. The state in *rps is initialized implicitly when labnum
+ * is zero.
+ *
+ * Returns 1 if the parse is proceeding successfully, 0 if the domain
+ * name is definitely invalid and the parse must be abandoned.
+ */
+
+extern bool adns__revparse_done(struct revparse_state *rps,
+ const char *dgram, int nlabels,
+ adns_rrtype *rrtype_r, adns_sockaddr *addr_r);
+/* Finishes parsing a reverse-domain name, given the total number of
+ * labels in the name. On success, fills in the af and protocol
+ * address in *addr_r, and the forward query type in *rrtype_r
+ * (because that turns out to be useful). Returns 1 if the parse
+ * was successful.
+ */
+
/* From setup.c: */
int adns__setnonblock(adns_state ads, int fd); /* => errno value */
/* From general.c: */
+void adns__vlprintf(adns_state ads, const char *fmt, va_list al);
+void adns__lprintf(adns_state ads, const char *fmt,
+ ...) PRINTFFORMAT(2,3);
+
void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
int serv, adns_query qu, const char *fmt, va_list al);
const char *fmt, ...) PRINTFFORMAT(4,5);
int adns__vbuf_ensure(vbuf *vb, int want);
-int adns__vbuf_appendstr(vbuf *vb, const char *data); /* does not include nul */
+int adns__vbuf_appendstr(vbuf *vb, const char *data); /* doesn't include nul */
int adns__vbuf_append(vbuf *vb, const byte *data, int len);
/* 1=>success, 0=>realloc failed */
void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
void adns__vbuf_free(vbuf *vb);
const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
- vbuf *vb, const byte *dgram, int dglen, int cbyte);
+ vbuf *vb,
+ const byte *dgram, int dglen, int cbyte);
/* Unpicks a domain in a datagram and returns a string suitable for
* printing it as. Never fails - if an error occurs, it will
* return some kind of string describing the error.
* vb before using the return value.
*/
+int adns__getrrsz_default(const typeinfo *typei, adns_rrtype type);
+/* Default function for the `getrrsz' type hook; returns the `fixed_rrsz'
+ * value from the typeinfo entry.
+ */
+
void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
int (*needswap)(void *context, const void *a, const void *b),
void *context);
adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
const char *owner, int ol,
- const typeinfo *typei, adns_queryflags flags);
+ const typeinfo *typei, adns_rrtype type,
+ adns_queryflags flags);
/* 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,
+ const byte *qd_dgram, int qd_dglen,
+ int qd_begin,
adns_rrtype type, adns_queryflags flags);
/* Same as adns__mkquery, but takes the owner domain from an existing datagram.
* That domain must be correct and untruncated.
* might be broken, but no reconnect will be attempted.
*/
+struct udpsocket *adns__udpsocket_by_af(adns_state ads, int af);
+/* Find the UDP socket structure in ads which has the given address family.
+ * Return null if there isn't one.
+ *
+ * This is used during initialization, so ads is only partially filled in.
+ * The requirements are that nudp is set, and that udpsocket[i].af are
+ * defined for 0<=i<nudp.
+ */
+
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.)
+ * (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: */
adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
- const typeinfo *typei, vbuf *qumsg_vb, int id,
+ adns_query parent,
+ 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.
* 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
* answer->cname and answer->owner are _preserved.
*/
-void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz);
+void adns__transfer_interim(adns_query from, adns_query to, void *block);
/* Transfers an interim allocation from one query to another, so that
* the `to' query will have room for the data when we get to makefinal
* and so that the free will happen when the `to' query is freed
* TTLs get inherited by their parents.
*/
+void adns__free_interim(adns_query qu, void *p);
+/* Forget about a block allocated by adns__alloc_interim.
+ */
+
void *adns__alloc_mine(adns_query qu, size_t sz);
/* Like _interim, but does not record the length for later
* copying into the answer. This just ensures that the memory
* in a datagram and discover that we need to retry the query.
*/
+void adns__cancel(adns_query qu);
void adns__query_done(adns_query qu);
-void adns__query_fail(adns_query qu, adns_status stat);
+void adns__query_fail(adns_query qu, adns_status st);
+void adns__cancel_children(adns_query qu);
+
+void adns__returning(adns_state ads, adns_query qu);
+/* Must be called before returning from adns any time that we have
+ * progressed (including made, finished or destroyed) queries.
+ *
+ * Might reenter adns via internal query callbacks, so
+ * external-faciing functions which call adns__returning should
+ * normally be avoided in internal code. */
/* From reply.c: */
* serv may be -1, qu may be null - they are for error reporting.
*/
-adns_status adns__findlabel_next(findlabel_state *fls, int *lablen_r, int *labstart_r);
+adns_status adns__findlabel_next(findlabel_state *fls,
+ int *lablen_r, int *labstart_r);
/* Then, call this one repeatedly.
*
* It will return adns_s_ok if all is well, and tell you the length
adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
vbuf *vb, parsedomain_flags flags,
- const byte *dgram, int dglen, int *cbyte_io, int max);
+ const byte *dgram, int dglen, int *cbyte_io,
+ int max);
/* vb must already have been initialised; it will be reset if necessary.
* If there is truncation, vb->used will be set to 0; otherwise
* (if there is no error) vb will be null-terminated.
*/
adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
- adns_query qu, vbuf *vb, parsedomain_flags flags,
+ adns_query qu, vbuf *vb,
+ parsedomain_flags flags,
const byte *dgram);
/* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
* for continuing an existing domain or some such of some kind. Also, unlike
adns_status adns__findrr_anychk(adns_query qu, int serv,
const byte *dgram, int dglen, int *cbyte_io,
- int *type_r, int *class_r, unsigned long *ttl_r,
+ int *type_r, int *class_r,
+ unsigned long *ttl_r,
int *rdlen_r, int *rdstart_r,
- const byte *eo_dgram, int eo_dglen, int eo_cbyte,
- int *eo_matched_r);
+ const byte *eo_dgram, int eo_dglen,
+ int eo_cbyte, int *eo_matched_r);
/* Like adns__findrr_checked, except that the datagram and
* owner to compare with can be specified explicitly.
*
* untruncated.
*/
-void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now);
+void adns__update_expires(adns_query qu, unsigned long ttl,
+ struct timeval now);
/* Updates the `expires' field in the query, so that it doesn't exceed
* now + ttl.
*/
int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
+bool adns__labels_equal(const byte *a, int al, const byte *b, int bl);
+
/* From event.c: */
void adns__tcp_broken(adns_state ads, const char *what, const char *why);
void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
struct timeval *tv_buf);
+/* Call with care - might reentrantly cause queries to be completed! */
int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
void adns__fdevents(adns_state ads,
/* Useful static inline functions: */
-static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
+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');
}
-static inline int ctype_822special(int c) { return strchr("()<>@,;:\\\".[]",c) != 0; }
+static inline int ctype_toupper(int c) {
+ return ctype_alpha(c) ? (c & ~32) : c;
+}
+static inline int ctype_822special(int c) {
+ return strchr("()<>@,;:\\\".[]",c) != 0;
+}
static inline int ctype_domainunquoted(int c) {
return ctype_alpha(c) || ctype_digit(c) || (strchr("-_/+",c) != 0);
}
/* Useful macros */
-#define MEM_ROUND(sz) \
- (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
+#define MEM_ROUND(sz) \
+ (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
* sizeof(union maxalign) )
#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))
-#define GET_L(cb,tv) ( (tv)=0, \
- (tv)|=(GETIL_B((cb))<<24), \
- (tv)|=(GETIL_B((cb))<<16), \
- (tv)|=(GETIL_B((cb))<<8), \
- (tv)|=GETIL_B(cb), \
+#define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
+#define GET_L(cb,tv) ( (tv)=0, \
+ (tv)|=(GETIL_B((cb))<<24), \
+ (tv)|=(GETIL_B((cb))<<16), \
+ (tv)|=(GETIL_B((cb))<<8), \
+ (tv)|=GETIL_B(cb), \
(tv) )
#endif
~ianmdlvl / adns.git / blobdiff