Date: Thu, 06 Apr 2000 12:53:44 +0900 From: Yoshinobu Inoue <shin@nd.net.fujitsu.co.jp> To: cpiazza@jaxon.net Cc: current@FreeBSD.ORG Subject: Re: 75 second delay using telnet/ssh (ipv6 related) Message-ID: <20000406125344R.shin@nd.net.fujitsu.co.jp> In-Reply-To: <20000402124742P.shin@nd.net.fujitsu.co.jp> References: <20000402075551N.shin@nd.net.fujitsu.co.jp> <20000401193005.A353@norn.ca.eu.org> <20000402124742P.shin@nd.net.fujitsu.co.jp>
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> > > > Sorry for the inconvenience and I'll try the fix.
> > >
> > > Sorry to be late, but I tried resolver fix and it seems to work.
> > > This should remove such 75 seconds delay in apps which use
> > > getaddrinfo().
> > >
> > > Please review and try this patches.
> >
> > I applied it and am running with it now, but I can't say one way or another
> > if it has fixed the problem :-). It only cropped up every couple of
> > weeks and seemingly random at that. I'll assume it works if I don't see
> > it happening again.
> >
> > Thanks,
>
> OK, anyway it is rather critical fix, so I think it needs some
> testing period.
I did a little bit cleanup, and made new patches.
(with no behaviour change)
I already received several positive confirmations for the
patches.
I'll wait more several days and will commit this if no
significant problem is found for this.
Thanks,
Yoshinobu Inoue
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Index: getaddrinfo.c
===================================================================
RCS file: /home/ncvs/src/lib/libc/net/getaddrinfo.c,v
retrieving revision 1.9
diff -u -r1.9 getaddrinfo.c
--- getaddrinfo.c 2000/02/19 16:10:12 1.9
+++ getaddrinfo.c 2000/04/06 03:50:46
@@ -108,7 +108,6 @@
};
struct explore {
- int e_af;
int e_socktype;
int e_protocol;
const char *e_protostr;
@@ -119,15 +118,10 @@
};
static const struct explore explore[] = {
-#ifdef INET6
- { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
- { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
- { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 },
-#endif
- { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
- { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
- { PF_INET, SOCK_RAW, ANY, NULL, 0x05 },
- { -1, 0, 0, NULL, 0 },
+ { SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
+ { SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
+ { SOCK_RAW, ANY, NULL, 0x05 },
+ { 0, 0, NULL, 0 },
};
#ifdef INET6
@@ -136,7 +130,8 @@
#define PTON_MAX 4
#endif
-
+extern struct hostent * _getipnodebyname_multi __P((const char *name,
+ int af, int flags, int *errp));
static int str_isnumber __P((const char *));
static int explore_fqdn __P((const struct addrinfo *, const char *,
const char *, struct addrinfo **));
@@ -307,9 +302,7 @@
if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
int matched = 0;
- for (ex = explore; ex->e_af >= 0; ex++) {
- if (pai->ai_family != ex->e_af)
- continue;
+ for (ex = explore; ex->e_socktype; ex++) {
if (ex->e_socktype == ANY)
continue;
if (ex->e_protocol == ANY)
@@ -353,10 +346,12 @@
}
/* NULL hostname, or numeric hostname */
- for (ex = explore; ex->e_af >= 0; ex++) {
+ for (afd = afdl; afd->a_af; afd++)
+ {
+ for (ex = explore; ex->e_socktype; ex++) {
*pai = ai0;
- if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
+ if (!MATCH_FAMILY(pai->ai_family, afd->a_af, WILD_AF(ex)))
continue;
if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
continue;
@@ -364,7 +359,7 @@
continue;
if (pai->ai_family == PF_UNSPEC)
- pai->ai_family = ex->e_af;
+ pai->ai_family = afd->a_af;
if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
pai->ai_socktype = ex->e_socktype;
if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
@@ -381,6 +376,7 @@
while (cur && cur->ai_next)
cur = cur->ai_next;
}
+ }
/*
* XXX
@@ -394,27 +390,12 @@
ERR(EAI_NONAME);
if (hostname == NULL)
ERR(EAI_NONAME);
-
- /*
- * hostname as alphabetical name.
- * we would like to prefer AF_INET6 than AF_INET, so we'll make a
- * outer loop by AFs.
- */
- for (afd = afdl; afd->a_af; afd++) {
- *pai = ai0;
- if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1))
- continue;
-
- for (ex = explore; ex->e_af >= 0; ex++) {
+ /* hostname as alphabetical name. */
+ {
+ for (ex = explore; ex->e_socktype; ex++) {
*pai = ai0;
- if (pai->ai_family == PF_UNSPEC)
- pai->ai_family = afd->a_af;
-
- if (!MATCH_FAMILY(pai->ai_family, ex->e_af,
- WILD_AF(ex)))
- continue;
if (!MATCH(pai->ai_socktype, ex->e_socktype,
WILD_SOCKTYPE(ex))) {
continue;
@@ -424,8 +405,6 @@
continue;
}
- if (pai->ai_family == PF_UNSPEC)
- pai->ai_family = ex->e_af;
if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
pai->ai_socktype = ex->e_socktype;
if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
@@ -485,12 +464,8 @@
if (get_portmatch(pai, servname) != 0)
return 0;
- afd = find_afd(pai->ai_family);
- if (afd == NULL)
- return 0;
-
- hp = getipnodebyname(hostname, pai->ai_family, AI_ADDRCONFIG,
- &h_error);
+ hp = _getipnodebyname_multi(hostname, pai->ai_family, AI_ADDRCONFIG,
+ &h_error);
if (hp == NULL) {
switch (h_error) {
case HOST_NOT_FOUND:
@@ -519,8 +494,12 @@
for (i = 0; hp->h_addr_list[i] != NULL; i++) {
af = hp->h_addrtype;
ap = hp->h_addr_list[i];
+
+ if (pai->ai_family != AF_UNSPEC && af != pai->ai_family)
+ continue;
- if (af != pai->ai_family)
+ afd = find_afd(af);
+ if (afd == NULL)
continue;
GET_AI(cur->ai_next, afd, ap);
Index: name6.c
===================================================================
RCS file: /home/ncvs/src/lib/libc/net/name6.c,v
retrieving revision 1.7
diff -u -r1.7 name6.c
--- name6.c 2000/03/15 15:04:54 1.7
+++ name6.c 2000/04/06 03:50:47
@@ -42,11 +42,13 @@
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
+#include <sys/queue.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
+#include <errno.h>
#include <netdb.h>
#include <resolv.h>
#include <stdio.h>
@@ -255,8 +257,6 @@
if (flags & AI_ADDRCONFIG) {
int s;
- if ((s = socket(af, SOCK_DGRAM, 0)) < 0)
- return NULL;
/*
* TODO:
* Note that implementation dependent test for address
@@ -264,7 +264,23 @@
* (or apropriate interval),
* because addresses will be dynamically assigned or deleted.
*/
- _close(s);
+ if (af == AF_UNSPEC) {
+ if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
+ af = AF_INET;
+ else {
+ _close(s);
+ if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
+ af = AF_INET6;
+ else
+ _close(s);
+ }
+
+ }
+ if (af != AF_UNSPEC) {
+ if ((s = socket(af, SOCK_DGRAM, 0)) < 0)
+ return NULL;
+ _close(s);
+ }
}
for (i = 0; i < MAXHOSTCONF; i++) {
@@ -277,16 +293,19 @@
return NULL;
}
+/* getipnodebyname() internal routine for multiple query(PF_UNSPEC) support. */
struct hostent *
-getipnodebyname(const char *name, int af, int flags, int *errp)
+_getipnodebyname_multi(const char *name, int af, int flags, int *errp)
{
struct hostent *hp;
union inx_addr addrbuf;
+ /* XXX: PF_UNSPEC is only supposed to be passed from getaddrinfo() */
if (af != AF_INET
#ifdef INET6
&& af != AF_INET6
#endif
+ && af != PF_UNSPEC
)
{
*errp = NO_RECOVERY;
@@ -341,6 +360,21 @@
}
struct hostent *
+getipnodebyname(const char *name, int af, int flags, int *errp)
+{
+ if (af != AF_INET
+#ifdef INET6
+ && af != AF_INET6
+#endif
+ )
+ {
+ *errp = NO_RECOVERY;
+ return NULL;
+ }
+ return(_getipnodebyname_multi(name, af ,flags, errp));
+}
+
+struct hostent *
getipnodebyaddr(const void *src, size_t len, int af, int *errp)
{
struct hostent *hp;
@@ -746,6 +780,7 @@
char *aliases[MAXALIASES + 1], *addrs[2];
union inx_addr addrbuf;
char buf[BUFSIZ];
+ int af0 = af;
if ((fp = _files_open(errp)) == NULL)
return NULL;
@@ -766,11 +801,39 @@
}
if (!match)
continue;
- if ((af == AF_INET
- ? inet_aton(addrstr, (struct in_addr *)&addrbuf)
- : inet_pton(af, addrstr, &addrbuf)) != 1) {
+ switch (af0) {
+ case AF_INET:
+ if (inet_aton(addrstr, (struct in_addr *)&addrbuf)
+ != 1) {
+ *errp = NO_DATA; /* name found */
+ continue;
+ }
+ af = af0;
+ break;
+#ifdef INET6
+ case AF_INET6:
+ if (inet_pton(af, addrstr, &addrbuf) != 1) {
+ *errp = NO_DATA; /* name found */
+ continue;
+ }
+ af = af0;
+ break;
+#endif
+ case AF_UNSPEC:
+ if (inet_aton(addrstr, (struct in_addr *)&addrbuf)
+ == 1) {
+ af = AF_INET;
+ break;
+ }
+#ifdef INET6
+ if (inet_pton(AF_INET6, addrstr, &addrbuf) == 1) {
+ af = AF_INET6;
+ break;
+ }
+#endif
*errp = NO_DATA; /* name found */
continue;
+ /* NOTREACHED */
}
hp = &hpbuf;
hp->h_name = cname;
@@ -842,6 +905,8 @@
{
struct hostent *hp = NULL;
+ if (af == AF_UNSPEC)
+ af = AF_INET;
if (af == AF_INET) {
hp = _gethostbynisname(name, af);
if (hp != NULL)
@@ -870,15 +935,22 @@
#define DNS_ASSERT(X) if (!(X)) { goto badanswer; }
#endif
+struct __res_type_list {
+ SLIST_ENTRY(__res_type_list) rtl_entry;
+ int rtl_type;
+};
+
static struct hostent *
-_dns_ghbyname(const char *name, int af, int *errp)
+_gethpbyanswer(answer, anslen, qtype, errp)
+ const u_char *answer;
+ int anslen;
+ int qtype;
+ int *errp;
{
int n;
- u_char answer[BUFSIZ];
char tbuf[MAXDNAME+1];
HEADER *hp;
- u_char *cp, *eom;
- int qtype;
+ const u_char *cp, *eom;
int type, class, ancount, qdcount;
u_long ttl;
char hostbuf[BUFSIZ];
@@ -889,30 +961,17 @@
int buflen;
int na, nh;
- if ((_res.options & RES_INIT) == 0) {
- if (res_init() < 0) {
- *errp = h_errno;
- return NULL;
- }
- }
hbuf.h_aliases = alist;
- hbuf.h_addrtype = af;
- hbuf.h_length = ADDRLEN(af);
- hbuf.h_addr_list = hlist;
- na = nh = 0;
-
+ hbuf.h_addrtype =
#ifdef INET6
- qtype = (af == AF_INET6 ? T_AAAA : T_A);
-#else
- qtype = T_A;
+ (qtype == T_AAAA) ? AF_INET6 :
#endif
- n = res_search(name, C_IN, qtype, answer, sizeof(answer));
- if (n < 0) {
- *errp = h_errno;
- return NULL;
- }
+ AF_INET;
+ hbuf.h_length = ADDRLEN(hbuf.h_addrtype);
+ hbuf.h_addr_list = hlist;
+ na = nh = 0;
hp = (HEADER *)answer;
- eom = answer + n;
+ eom = answer + anslen;
ancount = ntohs(hp->ancount);
qdcount = ntohs(hp->qdcount);
DNS_ASSERT(qdcount == 1);
@@ -992,6 +1051,210 @@
alist[na] = NULL;
hlist[nh] = NULL;
return _hpcopy(&hbuf, errp);
+}
+
+/* res_search() variant with multiple query support. */
+static struct hostent *
+_res_search_multi(name, rtl, errp)
+ const char *name; /* domain name */
+ struct __res_type_list *rtl; /* list of query types */
+ int *errp;
+{
+ u_char answer[BUFSIZ]; /* buffer to put answer */
+ const char *cp, * const *domain;
+ struct hostent *hp0 = NULL, *hp;
+ u_int dots;
+ int trailing_dot, ret, saved_herrno;
+ int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
+ struct __res_type_list *rtl0 = rtl;
+
+ if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
+ *errp = NETDB_INTERNAL;
+ return (NULL);
+ }
+ dots = 0;
+ for (cp = name; *cp; cp++)
+ dots += (*cp == '.');
+ trailing_dot = 0;
+ if (cp > name && *--cp == '.')
+ trailing_dot++;
+
+ /* If there aren't any dots, it could be a user-level alias */
+ if (!dots && (cp = hostalias(name)) != NULL) {
+ for(rtl = rtl0; rtl != NULL;
+ rtl = SLIST_NEXT(rtl, rtl_entry)) {
+ ret = res_query(cp, C_IN, rtl->rtl_type, answer,
+ sizeof(answer));
+ if (ret > 0) {
+ hp = _gethpbyanswer(answer, ret, rtl->rtl_type,
+ errp);
+ hp0 = _hpmerge(hp0, hp, errp);
+ }
+ }
+ return (hp0);
+ }
+
+ /*
+ * If there are dots in the name already, let's just give it a try
+ * 'as is'. The threshold can be set with the "ndots" option.
+ */
+ saved_herrno = -1;
+ if (dots >= _res.ndots) {
+ for(rtl = rtl0; rtl != NULL;
+ rtl = SLIST_NEXT(rtl, rtl_entry)) {
+ ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type,
+ answer, sizeof(answer));
+ if (ret > 0) {
+ hp = _gethpbyanswer(answer, ret, rtl->rtl_type,
+ errp);
+ hp0 = _hpmerge(hp0, hp, errp);
+ }
+ }
+ if (hp0 != NULL)
+ return (hp0);
+ saved_herrno = *errp;
+ tried_as_is++;
+ }
+
+ /*
+ * We do at least one level of search if
+ * - there is no dot and RES_DEFNAME is set, or
+ * - there is at least one dot, there is no trailing dot,
+ * and RES_DNSRCH is set.
+ */
+ if ((!dots && (_res.options & RES_DEFNAMES)) ||
+ (dots && !trailing_dot && (_res.options & RES_DNSRCH))) {
+ int done = 0;
+
+ for (domain = (const char * const *)_res.dnsrch;
+ *domain && !done;
+ domain++) {
+
+ for(rtl = rtl0; rtl != NULL;
+ rtl = SLIST_NEXT(rtl, rtl_entry)) {
+ ret = res_querydomain(name, *domain, C_IN,
+ rtl->rtl_type,
+ answer, sizeof(answer));
+ if (ret > 0) {
+ hp = _gethpbyanswer(answer, ret,
+ rtl->rtl_type,
+ errp);
+ hp0 = _hpmerge(hp0, hp, errp);
+ }
+ }
+ if (hp0 != NULL)
+ return (hp0);
+
+ /*
+ * If no server present, give up.
+ * If name isn't found in this domain,
+ * keep trying higher domains in the search list
+ * (if that's enabled).
+ * On a NO_DATA error, keep trying, otherwise
+ * a wildcard entry of another type could keep us
+ * from finding this entry higher in the domain.
+ * If we get some other error (negative answer or
+ * server failure), then stop searching up,
+ * but try the input name below in case it's
+ * fully-qualified.
+ */
+ if (errno == ECONNREFUSED) {
+ *errp = TRY_AGAIN;
+ return (NULL);
+ }
+
+ switch (*errp) {
+ case NO_DATA:
+ got_nodata++;
+ /* FALLTHROUGH */
+ case HOST_NOT_FOUND:
+ /* keep trying */
+ break;
+ case TRY_AGAIN:
+ if (((HEADER *)answer)->rcode == SERVFAIL) {
+ /* try next search element, if any */
+ got_servfail++;
+ break;
+ }
+ /* FALLTHROUGH */
+ default:
+ /* anything else implies that we're done */
+ done++;
+ }
+
+ /* if we got here for some reason other than DNSRCH,
+ * we only wanted one iteration of the loop, so stop.
+ */
+ if (!(_res.options & RES_DNSRCH))
+ done++;
+ }
+ }
+
+ /*
+ * If we have not already tried the name "as is", do that now.
+ * note that we do this regardless of how many dots were in the
+ * name or whether it ends with a dot unless NOTLDQUERY is set.
+ */
+ if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) {
+ for(rtl = rtl0; rtl != NULL;
+ rtl = SLIST_NEXT(rtl, rtl_entry)) {
+ ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type,
+ answer, sizeof(answer));
+ if (ret > 0) {
+ hp = _gethpbyanswer(answer, ret, rtl->rtl_type,
+ errp);
+ hp0 = _hpmerge(hp0, hp, errp);
+ }
+ }
+ if (hp0 != NULL)
+ return (hp0);
+ }
+
+ /* if we got here, we didn't satisfy the search.
+ * if we did an initial full query, return that query's h_errno
+ * (note that we wouldn't be here if that query had succeeded).
+ * else if we ever got a nodata, send that back as the reason.
+ * else send back meaningless h_errno, that being the one from
+ * the last DNSRCH we did.
+ */
+ if (saved_herrno != -1)
+ *errp = saved_herrno;
+ else if (got_nodata)
+ *errp = NO_DATA;
+ else if (got_servfail)
+ *errp = TRY_AGAIN;
+ return (NULL);
+}
+
+static struct hostent *
+_dns_ghbyname(const char *name, int af, int *errp)
+{
+ struct __res_type_list *rtl, rtl4;
+#ifdef INET6
+ struct __res_type_list rtl6;
+#endif
+
+#ifdef INET6
+ switch (af) {
+ case AF_UNSPEC:
+ SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A;
+ SLIST_NEXT(&rtl6, rtl_entry) = &rtl4; rtl6.rtl_type = T_AAAA;
+ rtl = &rtl6;
+ break;
+ case AF_INET6:
+ SLIST_NEXT(&rtl6, rtl_entry) = NULL; rtl6.rtl_type = T_AAAA;
+ rtl = &rtl6;
+ break;
+ case AF_INET:
+ SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A;
+ rtl = &rtl4;
+ break;
+ }
+#else
+ SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A;
+ rtl = &rtl4;
+#endif
+ return(_res_search_multi(name, rtl, errp));
}
static struct hostent *
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