/*
* adns.h
- * - adns user-visible API (single-threaded, without any locking)
+ * - adns user-visible API
*/
/*
*
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*
- * $Id: adns.h,v 1.95 2006/04/08 14:36:57 ian Exp $
+ * $Id: adns.h,v 1.96 2006/08/09 11:16:59 ian Exp $
*/
#ifndef ADNS_H_INCLUDED
#include <netinet/in.h>
#include <sys/time.h>
#include <unistd.h>
+#include <net/if.h>
#ifdef __cplusplus
extern "C" { /* I really dislike this - iwj. */
#endif
+/* Whether to support address families other than IPv4 in responses which use
+ * the `adns_rr_addr' structure. This is a source-compatibility issue: old
+ * clients may not expect to find address families other than AF_INET in
+ * their query results. There's a separate binary compatibility issue to do
+ * with the size of the `adns_rr_addr' structure, but we'll assume you can
+ * cope with that because you have this header file. Define
+ * `ADNS_FEATURE_IPV4ONLY' if you only want to see AF_INET addresses, or
+ * `ADNS_FEATURE_MANYAF' to allow multiple address families; the default is
+ * currently to stick with AF_INET only, but this is likely to change in a
+ * later release of ADNS.
+ */
+#if !defined(ADNS_FEATURE_IPV4ONLY) && !defined(ADNS_FEATURE_MANYAF)
+# define ADNS_FEATURE_IPV4ONLY
+#elif defined(ADNS_FEATURE_IPV4ONLY) && defined(ADNS_FEATURE_MANYAF)
+# error "Feature flags ADNS_FEATURE_IPV4ONLY and ..._MANYAF are incompatible"
+#endif
+
/* All struct in_addr anywhere in adns are in NETWORK byte order. */
typedef struct adns__state *adns_state;
adns_if_eintr= 0x0020,/* allow _wait and _synchronous to return EINTR */
adns_if_nosigpipe= 0x0040,/* applic has SIGPIPE ignored, do not protect */
adns_if_checkc_entex=0x0100,/* consistency checks on entry/exit to adns fns */
- adns_if_checkc_freq= 0x0300 /* consistency checks very frequently (slow!) */
+ adns_if_checkc_freq= 0x0300,/* consistency checks very frequently (slow!) */
+
+ adns_if_af_v4only= 0x0400,/* only return IPv4 addresses, given the choice */
+ adns_if_af_v6only= 0x0800,/* only return IPv6 addresses, ... */
+ adns_if_afmask= adns_if_af_v4only|adns_if_af_v6only
+ /* Only set one of these. They are policy flags, and overridden by the
+ * adns_af:... options in resolv.conf. If the adns_qf_ipv... query
+ * flags are incompatible with these settings (in the sense that no
+ * address families are permitted at all) then the query flags take
+ * precedence; otherwise only records which satisfy all of the stated
+ * requirements are allowed.
+ */
} adns_initflags;
typedef enum { /* In general, or together the desired flags: */
adns_qf_quotefail_cname=0x00000080,/* refuse if quote-req chars in CNAME we go via */
adns_qf_cname_loose= 0x00000100,/* allow refs to CNAMEs - without, get _s_cname */
adns_qf_cname_forbid= 0x00000200,/* don't follow CNAMEs, instead give _s_cname */
+ adns_qf_ipv4_only= 0x00000400,/* only ever return IPv4 addresses */
+ adns_qf_ipv6_only= 0x00000800,/* ... and don't bother looking for IPv4 */
+ adns_qf_ipv6_ok= 0x00000c00,/* returning IPv6 addresses is acceptable */
+ adns_qf_domapv4= 0x00001000,/* ... any IPv4 addresses should be v6-mapped */
+ adns_qf_ipv6_mapv4= adns_qf_ipv6_ok|adns_qf_domapv4,
+ adns__qf_afmask= 0x00001c00,/* all the above flag bits */
+ adns_qf_addrlit_scope_forbid=0x00002000,/* forbid %<scope> in IPv6 literals */
+ adns_qf_addrlit_scope_numeric=0x00004000,/* %<scope> may only be numeric */
adns__qf_internalmask= 0x0ff00000
} adns_queryflags;
typedef enum {
adns_rrt_typemask= 0x0ffff,
- adns__qtf_deref= 0x10000,/* dereference domains; perhaps get extra data */
+ adns_rrt_reprmask= 0xffffff,
+ adns__qtf_deref_bit=0x10000,/* internal version of ..._deref below */
adns__qtf_mail822= 0x20000,/* return mailboxes in RFC822 rcpt field fmt */
adns_r_unknown= 0x40000,
*
* Don't forget adns_qf_quoteok if that's what you want. */
+ adns__qtf_bigaddr=0x1000000,/* use the new larger sockaddr union */
+ adns__qtf_manyaf= 0x2000000,/* permitted to return multiple address families */
+
+ adns__qtf_deref= adns__qtf_deref_bit|adns__qtf_bigaddr
+#ifdef ADNS_FEATURE_MANYAF
+ |adns__qtf_manyaf
+#endif
+ ,/* dereference domains; perhaps get extra data */
+
adns_r_none= 0,
adns_r_a= 1,
adns_r_rp_raw= 17,
adns_r_rp= adns_r_rp_raw|adns__qtf_mail822,
+ adns_r_aaaa= 28,
+
/* For SRV records, query domain without _qf_quoteok_query must look
* as expected from SRV RFC with hostname-like Name. _With_
* _quoteok_query, any query domain is allowed. */
} adns_status;
+typedef union {
+ struct sockaddr sa;
+ struct sockaddr_in inet;
+} adns_sockaddr_v4only;
+
+typedef union {
+ struct sockaddr sa;
+ struct sockaddr_in inet;
+ struct sockaddr_in6 inet6;
+ char adns__padding[240]; /* Good idea? I'm inclined to think not. */
+} adns_sockaddr;
+
typedef struct {
int len;
- union {
- struct sockaddr sa;
- struct sockaddr_in inet;
- } addr;
+ adns_sockaddr addr;
} adns_rr_addr;
+typedef struct {
+ int len;
+ adns_sockaddr_v4only addr;
+} adns_rr_addr_v4only;
+
typedef struct {
char *host;
adns_status astatus;
adns_rr_intstr *(*manyistr); /* txt (list strs ends with i=-1, str=0)*/
adns_rr_addr *addr; /* addr */
struct in_addr *inaddr; /* a */
+ struct in6_addr *in6addr; /* aaaa */
adns_rr_hostaddr *hostaddr; /* ns */
adns_rr_intstrpair *intstrpair; /* hinfo */
adns_rr_strpair *strpair; /* rp, rp_raw */
* requested.
*/
+/* Threads:
+ * adns does not use any static modifiable state, so it
+ * is safe to call adns_init several times and then use the
+ * resulting adns_states concurrently.
+ * However, it is NOT safe to make simultaneous calls into
+ * adns using the same adns_state; a single adns_state must be used
+ * only by one thread at a time. You can solve this problem by
+ * having one adns_state per thread, or if that isn't feasible, you
+ * could maintain a pool of adns_states. Unfortunately neither of
+ * these approaches has optimal performance.
+ */
+
int adns_init(adns_state *newstate_r, adns_initflags flags,
FILE *diagfile /*0=>stderr*/);
* Changes the consistency checking frequency; this overrides the
* setting of adns_if_check_entex, adns_if_check_freq, or neither,
* in the flags passed to adns_init.
+ *
+ * adns_af:v4only
+ * adns_af:v6only
+ * adns_af:any
+ * Controls whether ADNS looks for IPv4 (A records) and IPv6 (AAAA
+ * records) addresses when it's trying to build a socket address.
+ * The default is `any' which means to allow both. The `sortlist'
+ * directive can be used to control the relative preference of IPv4
+ * and IPv6 addresses if both are returned for the same query.
+ * These override the corresponding init flags (covered by
+ * adns_if_afmask).
*
* There are a number of environment variables which can modify the
* behaviour of adns. They take effect only if adns_init is used, and
* they will be cancelled.
*/
+#define ADNS_ADDR2TEXT_BUFLEN \
+ (INET6_ADDRSTRLEN + 1/*%*/ \
+ + ((IF_NAMESIZE-1) > 9 ? (IF_NAMESIZE-1) : 9/*uint32*/) \
+ + 1/* nul; included in IF_NAMESIZE */)
+
+int adns_text2addr(const char *text, uint16_t port, adns_queryflags flags,
+ struct sockaddr *sa,
+ socklen_t *salen /* set if OK or ENOSPC; otherwise undef */);
+int adns_addr2text(const struct sockaddr *sa, adns_queryflags flags,
+ char *buffer, int *buflen /* set iff ENOSPC */,
+ int *port_r /* may be 0 */);
+ /*
+ * port is always in host byte order and is simply copied to and
+ * from the appropriate sockaddr field (byteswapped as necessary).
+ *
+ * The only flags supported are adns_qf_addrlit_...; others are
+ * ignored.
+ *
+ * Error return values are:
+ *
+ * ENOSPC Output buffer is too small. Can only happen if
+ * *buflen < ADNS_ADDR2TEXT_BUFLEN or
+ * *salen < sizeof(adns_sockaddr). On return,
+ * *buflen or *salen has been updated by adns.
+ *
+ * EINVAL text has invalid syntax.
+ *
+ * text represents an address family not supported by
+ * this version of adns.
+ *
+ * Scoped address supplied (text contained "%" or
+ * sin6_scope_id nonzero) but caller specified
+ * adns_qf_addrlit_scope_forbid.
+ *
+ * Scope name (rather than number) supplied in text but
+ * caller specified adns_qf_addrlit_scope_numeric.
+ *
+ * EAFNOSUPPORT sa->sa_family is not supported (addr2text only).
+ *
+ * Only if neither adns_qf_addrlit_scope_forbid nor
+ * adns_qf_addrlit_scope_numeric are set:
+ *
+ * ENOSYS Scope name supplied in text but IPv6 address part of
+ * sockaddr is not a link local address.
+ *
+ * ENXIO Scope name supplied in text but if_nametoindex
+ * said it wasn't a valid local interface name.
+ *
+ * EIO Scoped address supplied but if_nametoindex failed
+ * in an unexpected way; adns has printed a message to
+ * stderr.
+ *
+ * any other if_nametoindex failed in a more-or-less expected way.
+ */
void adns_forallqueries_begin(adns_state ads);
adns_query adns_forallqueries_next(adns_state ads, void **context_r);
* In any case this call won't block.
*/
-#define ADNS_POLLFDS_RECOMMENDED 2
+#define ADNS_POLLFDS_RECOMMENDED 3
/* If you allocate an fds buf with at least RECOMMENDED entries then
* you are unlikely to need to enlarge it. You are recommended to do
* so if it's convenient. However, you must be prepared for adns to