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authorUlrich Drepper <drepper@redhat.com>2008-05-10 23:27:39 +0000
committerUlrich Drepper <drepper@redhat.com>2008-05-10 23:27:39 +0000
commit1eb946b93509b94db2bddce741f2f3b483418a6d (patch)
tree054e49d0b1be9539a0d778c4b1a6252ac4d68523 /resolv
parenta82e8bb8d0b51d30cb0d8d24f0ff0f72066cf2ce (diff)
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* include/resolv.h: Adjust __libc_res_nquery and __libc_res_nsend
prototypes. * include/arpa/nameser_compat.h: Define T_UNSPEC. * nis/Versions (libnss_nis): Export _nss_nis_gethostbyname4_r. (libnss_nisplus): Export _nss_nisplus_gethostbyname4_r. * nis/nss_nis/nis-hosts.c (LINE_PARSER): Change to also handle af==AF_UNSPEC. (_nss_nis_gethostbyname4_r): New function. * nis/nss_nisplus/nisplus-hosts.c (_nss_nisplus_parse_hostent): Change to also handle af==AF_UNSPEC. (get_tablename): New function. Use it to avoid duplication. (_nss_nisplus_gethostbyname4_r): New function. * nscd/aicache.c (addhstaiX): Use gethostbyname4_r function is available. * nss/Versions (libnss_files): Export _nss_files_gethostbyname4_r. * nss/nss.h: Define struct gaih_addrtuple. * nss/nss_files/files-hosts.c (LINE_PARSER): Change to also handle af==AF_UNSPEC. (_nss_files_gethostbyname4_r): New function. * resolv/Versions (libnss_dns): Export _nss_dns_gethostbyname4_r. * resolv/gethnmaddr.c: Adjust __libc_res_nsearch and __libc_res_nquery calls. * resolv/res_query.c (__libc_res_nquery): Take two additional parameters for second answer buffer. Handle type=T_UNSPEC to mean look up IPv4 and IPv6. Change all callers. * resolv/res_send.c (__libc_res_nsend): Take five aditional parameters for an additional query and answer buffer. Pass to send_vc and send_dg. (send_vc): Send possibly two requests and receive two answers. (send_dg): Likewise. * resolv/nss_dns/dns-host.c: Adjust calls to __libc_res_nsearch and __libc_res_nquery. (_nss_dns_gethostbyname4_r): New function. (gaih_getanswer_slice): Likewise. (gaih_getanswer): Likewise. * resolv/nss_dns/dns-canon.c (_nss_dns_getcanonname_r): Adjust __libc_res_nquery call. * resolv/nss_dns/dns-network.c (_nss_dns_getnetbyaddr_r): Likewise. (_nss_dns_getnetbyname_r): Adjust __libc_res_nsearch call. * sysdeps/posix/getaddrinfo.c: Use gethostbyname4_r function is available.
Diffstat (limited to 'resolv')
-rw-r--r--resolv/Versions1
-rw-r--r--resolv/gethnamaddr.c6
-rw-r--r--resolv/nss_dns/dns-canon.c4
-rw-r--r--resolv/nss_dns/dns-host.c337
-rw-r--r--resolv/nss_dns/dns-network.c6
-rw-r--r--resolv/res_query.c149
-rw-r--r--resolv/res_send.c323
7 files changed, 693 insertions, 133 deletions
diff --git a/resolv/Versions b/resolv/Versions
index fc2111a..355d95d 100644
--- a/resolv/Versions
+++ b/resolv/Versions
@@ -89,6 +89,7 @@ libnss_dns {
_nss_dns_gethostbyname_r; _nss_dns_getnetbyaddr_r;
_nss_dns_getnetbyname_r; _nss_dns_getcanonname_r;
_nss_dns_gethostbyaddr2_r;
+ _nss_dns_gethostbyname4_r;
}
}
diff --git a/resolv/gethnamaddr.c b/resolv/gethnamaddr.c
index 7be2315..2a9bd0b 100644
--- a/resolv/gethnamaddr.c
+++ b/resolv/gethnamaddr.c
@@ -621,7 +621,7 @@ gethostbyname2(name, af)
buf.buf = origbuf = (querybuf *) alloca (1024);
if ((n = __libc_res_nsearch(&_res, name, C_IN, type, buf.buf->buf, 1024,
- &buf.ptr)) < 0) {
+ &buf.ptr, NULL, NULL)) < 0) {
if (buf.buf != origbuf)
free (buf.buf);
Dprintf("res_nsearch failed (%d)\n", n);
@@ -716,12 +716,12 @@ gethostbyaddr(addr, len, af)
buf.buf = orig_buf = (querybuf *) alloca (1024);
n = __libc_res_nquery(&_res, qbuf, C_IN, T_PTR, buf.buf->buf, 1024,
- &buf.ptr);
+ &buf.ptr, NULL, NULL);
if (n < 0 && af == AF_INET6 && (_res.options & RES_NOIP6DOTINT) == 0) {
strcpy(qp, "ip6.int");
n = __libc_res_nquery(&_res, qbuf, C_IN, T_PTR, buf.buf->buf,
buf.buf != orig_buf ? MAXPACKET : 1024,
- &buf.ptr);
+ &buf.ptr, NULL, NULL);
}
if (n < 0) {
if (buf.buf != orig_buf)
diff --git a/resolv/nss_dns/dns-canon.c b/resolv/nss_dns/dns-canon.c
index fca6cd8..47949b8 100644
--- a/resolv/nss_dns/dns-canon.c
+++ b/resolv/nss_dns/dns-canon.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2004, 2006 Free Software Foundation, Inc.
+/* Copyright (C) 2004, 2006, 2008 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
@@ -61,7 +61,7 @@ _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen,
for (int i = 0; i < nqtypes; ++i)
{
int r = __libc_res_nquery (&_res, name, ns_c_in, qtypes[i],
- buf, sizeof (buf), &ansp.ptr);
+ buf, sizeof (buf), &ansp.ptr, NULL, NULL);
if (r > 0)
{
/* We need to decode the response. Just one question record.
diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c
index dfdf9c5..c52f9f7 100644
--- a/resolv/nss_dns/dns-host.c
+++ b/resolv/nss_dns/dns-host.c
@@ -71,6 +71,7 @@
* --Copyright--
*/
+#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <netdb.h>
@@ -127,6 +128,14 @@ static enum nss_status getanswer_r (const querybuf *answer, int anslen,
size_t buflen, int *errnop, int *h_errnop,
int map, int32_t *ttlp, char **canonp);
+static enum nss_status gaih_getanswer (const querybuf *answer1, int anslen1,
+ const querybuf *answer2, int anslen2,
+ const char *qname,
+ struct gaih_addrtuple **pat,
+ char *buffer, size_t buflen,
+ int *errnop, int *h_errnop,
+ int32_t *ttlp);
+
extern enum nss_status _nss_dns_gethostbyname3_r (const char *name, int af,
struct hostent *result,
char *buffer, size_t buflen,
@@ -186,11 +195,11 @@ _nss_dns_gethostbyname3_r (const char *name, int af, struct hostent *result,
host_buffer.buf = orig_host_buffer = (querybuf *) alloca (1024);
n = __libc_res_nsearch (&_res, name, C_IN, type, host_buffer.buf->buf,
- 1024, &host_buffer.ptr);
+ 1024, &host_buffer.ptr, NULL, NULL);
if (n < 0)
{
- enum nss_status status = (errno == ECONNREFUSED
- ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND);
+ status = (errno == ECONNREFUSED
+ ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND);
*h_errnop = h_errno;
if (h_errno == TRY_AGAIN)
*errnop = EAGAIN;
@@ -203,7 +212,8 @@ _nss_dns_gethostbyname3_r (const char *name, int af, struct hostent *result,
if (af == AF_INET6 && (_res.options & RES_USE_INET6))
n = __libc_res_nsearch (&_res, name, C_IN, T_A, host_buffer.buf->buf,
host_buffer.buf != orig_host_buffer
- ? MAXPACKET : 1024, &host_buffer.ptr);
+ ? MAXPACKET : 1024, &host_buffer.ptr,
+ NULL, NULL);
if (n < 0)
{
@@ -255,6 +265,70 @@ _nss_dns_gethostbyname_r (const char *name, struct hostent *result,
}
+enum nss_status
+_nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
+ char *buffer, size_t buflen, int *errnop,
+ int *herrnop, int32_t *ttlp)
+{
+ if (__res_maybe_init (&_res, 0) == -1)
+ return NSS_STATUS_UNAVAIL;
+
+ char tmp[NS_MAXDNAME];
+
+ /*
+ * if there aren't any dots, it could be a user-level alias.
+ * this is also done in res_query() since we are not the only
+ * function that looks up host names.
+ */
+ if (strchr (name, '.') == NULL)
+ {
+ const char *cp = res_hostalias (&_res, name, tmp, sizeof (tmp));
+ if (cp != NULL)
+ name = cp;
+ }
+
+ union
+ {
+ querybuf *buf;
+ u_char *ptr;
+ } host_buffer;
+ querybuf *orig_host_buffer;
+ host_buffer.buf = orig_host_buffer = (querybuf *) alloca (2048);
+ u_char *ans2p = NULL;
+ int nans2p = 0;
+
+ int olderr = errno;
+ enum nss_status status;
+ int n = __libc_res_nsearch (&_res, name, C_IN, T_UNSPEC,
+ host_buffer.buf->buf, 2048, &host_buffer.ptr,
+ &ans2p, &nans2p);
+ if (n < 0)
+ {
+ status = (errno == ECONNREFUSED
+ ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND);
+ *herrnop = h_errno;
+ if (h_errno == TRY_AGAIN)
+ *errnop = EAGAIN;
+ else
+ __set_errno (olderr);
+
+ if (host_buffer.buf != orig_host_buffer)
+ free (host_buffer.buf);
+
+ return status;
+ }
+
+ status = gaih_getanswer(host_buffer.buf, n, (const querybuf *) ans2p,
+ nans2p, name, pat, buffer, buflen,
+ errnop, herrnop, ttlp);
+
+ if (host_buffer.buf != orig_host_buffer)
+ free (host_buffer.buf);
+
+ return status;
+}
+
+
extern enum nss_status _nss_dns_gethostbyaddr2_r (const void *addr,
socklen_t len, int af,
struct hostent *result,
@@ -342,7 +416,8 @@ _nss_dns_gethostbyaddr2_r (const void *addr, socklen_t len, int af,
qp += sprintf (qp, "%02hhx", uaddr[n]);
strcpy (qp, "].ip6.arpa");
n = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR,
- host_buffer.buf->buf, 1024, &host_buffer.ptr);
+ host_buffer.buf->buf, 1024, &host_buffer.ptr,
+ NULL, NULL);
if (n >= 0)
goto got_it_already;
}
@@ -363,13 +438,14 @@ _nss_dns_gethostbyaddr2_r (const void *addr, socklen_t len, int af,
}
n = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer.buf->buf,
- 1024, &host_buffer.ptr);
+ 1024, &host_buffer.ptr, NULL, NULL);
if (n < 0 && af == AF_INET6 && (_res.options & RES_NOIP6DOTINT) == 0)
{
strcpy (qp, "ip6.int");
n = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer.buf->buf,
host_buffer.buf != orig_host_buffer
- ? MAXPACKET : 1024, &host_buffer.ptr);
+ ? MAXPACKET : 1024, &host_buffer.ptr,
+ NULL, NULL);
}
if (n < 0)
{
@@ -555,7 +631,8 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
if (n > 0 && bp[0] == '.')
bp[0] = '\0';
- if (n < 0 || (*name_ok) (bp) == 0)
+ if (__builtin_expect (n < 0 || ((*name_ok) (bp) == 0 && (errno = EBADMSG)),
+ 0))
{
*errnop = errno;
*h_errnop = NO_RECOVERY;
@@ -629,7 +706,7 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
continue; /* XXX - had_error++ ? */
}
- if ((qtype ==T_A || qtype == T_AAAA) && type == T_CNAME)
+ if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME)
{
if (ap >= &host_data->aliases[MAX_NR_ALIASES - 1])
continue;
@@ -857,3 +934,245 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
return ((qtype == T_A || qtype == T_AAAA) && ap != host_data->aliases
? NSS_STATUS_NOTFOUND : NSS_STATUS_TRYAGAIN);
}
+
+
+static enum nss_status
+gaih_getanswer_slice (const querybuf *answer, int anslen, const char *qname,
+ struct gaih_addrtuple ***patp,
+ char **bufferp, size_t *buflenp,
+ int *errnop, int *h_errnop, int32_t *ttlp, int *firstp)
+{
+ char *buffer = *bufferp;
+ size_t buflen = *buflenp;
+
+ struct gaih_addrtuple **pat = *patp;
+ const HEADER *hp = &answer->hdr;
+ int ancount = ntohs (hp->ancount);
+ int qdcount = ntohs (hp->qdcount);
+ const u_char *cp = answer->buf + HFIXEDSZ;
+ const u_char *end_of_message = answer->buf + anslen;
+ if (__builtin_expect (qdcount != 1, 0))
+ {
+ *h_errnop = NO_RECOVERY;
+ return NSS_STATUS_UNAVAIL;
+ }
+
+ u_char packtmp[NS_MAXCDNAME];
+ int n = __ns_name_unpack (answer->buf, end_of_message, cp,
+ packtmp, sizeof packtmp);
+ /* We unpack the name to check it for validity. But we do not need
+ it later. */
+ if (n != -1 && __ns_name_ntop (packtmp, buffer, buflen) == -1)
+ {
+ if (__builtin_expect (errno, 0) == EMSGSIZE)
+ {
+ too_small:
+ *errnop = ERANGE;
+ *h_errnop = NETDB_INTERNAL;
+ return NSS_STATUS_TRYAGAIN;
+ }
+
+ n = -1;
+ }
+
+ if (__builtin_expect (n < 0 || (res_hnok (buffer) == 0
+ && (errno = EBADMSG)), 0))
+ {
+ *errnop = errno;
+ *h_errnop = NO_RECOVERY;
+ return NSS_STATUS_UNAVAIL;
+ }
+ cp += n + QFIXEDSZ;
+
+ int haveanswer = 0;
+ int had_error = 0;
+ char *canon = NULL;
+ char *h_name = NULL;
+ int h_namelen = 0;
+
+ while (ancount-- > 0 && cp < end_of_message && had_error == 0)
+ {
+ n = __ns_name_unpack (answer->buf, end_of_message, cp,
+ packtmp, sizeof packtmp);
+ if (n != -1 &&
+ (h_namelen = __ns_name_ntop (packtmp, buffer, buflen)) == -1)
+ {
+ if (__builtin_expect (errno, 0) == EMSGSIZE)
+ goto too_small;
+
+ n = -1;
+ }
+ if (n < 0 || res_hnok (buffer) == 0)
+ {
+ ++had_error;
+ continue;
+ }
+ if (*firstp)
+ {
+ h_name = buffer;
+ buffer += h_namelen;
+ buflen -= h_namelen;
+ }
+
+ cp += n; /* name */
+ int type = ns_get16 (cp);
+ cp += INT16SZ; /* type */
+ int class = ns_get16 (cp);
+ cp += INT16SZ; /* class */
+ int32_t ttl = ns_get32 (cp);
+ cp += INT32SZ; /* TTL */
+ n = ns_get16 (cp);
+ cp += INT16SZ; /* len */
+
+ if (class != C_IN)
+ {
+ cp += n;
+ continue;
+ }
+
+ if (type == T_CNAME)
+ {
+ char tbuf[MAXDNAME];
+ n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf);
+ if (n < 0 || res_hnok (tbuf) == 0)
+ {
+ ++had_error;
+ continue;
+ }
+ cp += n;
+
+ if (*firstp)
+ {
+ /* Reclaim buffer space. */
+ if (h_name + h_namelen == buffer)
+ {
+ buffer = h_name;
+ buflen += h_namelen;
+ }
+
+ n = strlen (tbuf) + 1;
+ if (__builtin_expect (n > buflen, 0))
+ goto too_small;
+ if (__builtin_expect (n >= MAXHOSTNAMELEN, 0))
+ {
+ ++had_error;
+ continue;
+ }
+
+ canon = buffer;
+ buffer = __mempcpy (buffer, tbuf, n);
+ buflen -= n;
+ h_namelen = 0;
+ }
+ continue;
+ }
+ if (__builtin_expect (type == T_SIG, 0)
+ || __builtin_expect (type == T_KEY, 0)
+ || __builtin_expect (type == T_NXT, 0)
+ || __builtin_expect (type == T_PTR, 0))
+ {
+ /* We don't support DNSSEC yet. For now, ignore the record
+ and send a low priority message to syslog.
+
+ We also don't expect T_PTR messages. */
+ syslog (LOG_DEBUG | LOG_AUTH,
+ "getaddrinfo*.gaih_getanswer: got type \"%s\"",
+ p_type (type));
+ cp += n;
+ continue;
+ }
+ if (type != T_A && type != T_AAAA)
+ abort ();
+
+ if (*pat == NULL)
+ {
+ uintptr_t pad = (-(uintptr_t) buffer
+ % __alignof__ (struct gaih_addrtuple));
+ buffer += pad;
+ buflen = buflen > pad ? buflen - pad : 0;
+
+ if (__builtin_expect (buflen < sizeof (struct gaih_addrtuple),
+ 0))
+ {
+ *errnop = ERANGE;
+ *h_errnop = NETDB_INTERNAL;
+ return NSS_STATUS_TRYAGAIN;
+ }
+
+ *pat = (struct gaih_addrtuple *) buffer;
+ buffer += sizeof (struct gaih_addrtuple);
+ buflen -= sizeof (struct gaih_addrtuple);
+ }
+
+ (*pat)->name = NULL;
+ (*pat)->next = NULL;
+
+ if (*firstp)
+ {
+ if (ttl != 0 && ttlp != NULL)
+ *ttlp = ttl;
+
+ if (canon != NULL)
+ {
+ (*pat)->name = canon;
+
+ /* Reclaim buffer space. */
+ if (h_name + h_namelen == buffer)
+ {
+ buffer = h_name;
+ buflen += h_namelen;
+ }
+ }
+ else
+ (*pat)->name = h_name;
+
+ *firstp = 0;
+ }
+
+ (*pat)->family = type == T_A ? AF_INET : AF_INET6;
+ memcpy ((*pat)->addr, cp, n);
+ cp += n;
+ (*pat)->scopeid = 0;
+
+ pat = &((*pat)->next);
+
+ haveanswer = 1;
+ }
+
+ if (haveanswer)
+ {
+ *patp = pat;
+ *bufferp = buffer;
+ *buflenp = buflen;
+
+ *h_errnop = NETDB_SUCCESS;
+ return NSS_STATUS_SUCCESS;
+ }
+
+ /* Special case here: if the resolver sent a result but it only
+ contains a CNAME while we are looking for a T_A or T_AAAA record,
+ we fail with NOTFOUND instead of TRYAGAIN. */
+ return canon == NULL ? NSS_STATUS_TRYAGAIN : NSS_STATUS_NOTFOUND;
+}
+
+
+static enum nss_status
+gaih_getanswer (const querybuf *answer1, int anslen1, const querybuf *answer2,
+ int anslen2, const char *qname,
+ struct gaih_addrtuple **pat, char *buffer, size_t buflen,
+ int *errnop, int *h_errnop, int32_t *ttlp)
+{
+ int first = 1;
+
+ enum nss_status status = gaih_getanswer_slice(answer1, anslen1, qname,
+ &pat, &buffer, &buflen,
+ errnop, h_errnop, ttlp,
+ &first);
+ if ((status == NSS_STATUS_SUCCESS || status == NSS_STATUS_NOTFOUND)
+ && answer2 != NULL)
+ status = gaih_getanswer_slice(answer2, anslen2, qname,
+ &pat, &buffer, &buflen,
+ errnop, h_errnop, ttlp, &first);
+
+ return status;
+}
diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c
index 4552b5b..40736fb 100644
--- a/resolv/nss_dns/dns-network.c
+++ b/resolv/nss_dns/dns-network.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1996, 1997, 1998, 1999, 2002, 2004, 2007
+/* Copyright (C) 1996, 1997, 1998, 1999, 2002, 2004, 2007, 2008
Free Software Foundation, Inc.
This file is part of the GNU C Library.
Extended from original form by Ulrich Drepper <drepper@cygnus.com>, 1996.
@@ -130,7 +130,7 @@ _nss_dns_getnetbyname_r (const char *name, struct netent *result,
net_buffer.buf = orig_net_buffer = (querybuf *) alloca (1024);
anslen = __libc_res_nsearch (&_res, qbuf, C_IN, T_PTR, net_buffer.buf->buf,
- 1024, &net_buffer.ptr);
+ 1024, &net_buffer.ptr, NULL, NULL);
if (anslen < 0)
{
/* Nothing found. */
@@ -206,7 +206,7 @@ _nss_dns_getnetbyaddr_r (uint32_t net, int type, struct netent *result,
net_buffer.buf = orig_net_buffer = (querybuf *) alloca (1024);
anslen = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, net_buffer.buf->buf,
- 1024, &net_buffer.ptr);
+ 1024, &net_buffer.ptr, NULL, NULL);
if (anslen < 0)
{
/* Nothing found. */
diff --git a/resolv/res_query.c b/resolv/res_query.c
index 4371af5..a8e8d7b 100644
--- a/resolv/res_query.c
+++ b/resolv/res_query.c
@@ -97,7 +97,7 @@ static const char rcsid[] = "$BINDId: res_query.c,v 8.20 2000/02/29 05:39:12 vix
static int
__libc_res_nquerydomain(res_state statp, const char *name, const char *domain,
int class, int type, u_char *answer, int anslen,
- u_char **answerp);
+ u_char **answerp, u_char **answerp2, int *nanswerp2);
/*
* Formulate a normal query, send, and await answer.
@@ -115,15 +115,20 @@ __libc_res_nquery(res_state statp,
int class, int type, /* class and type of query */
u_char *answer, /* buffer to put answer */
int anslen, /* size of answer buffer */
- u_char **answerp) /* if buffer needs to be enlarged */
+ u_char **answerp, /* if buffer needs to be enlarged */
+ u_char **answerp2,
+ int *nanswerp2)
{
- u_char *buf;
HEADER *hp = (HEADER *) answer;
int n, use_malloc = 0;
u_int oflags = statp->_flags;
- size_t bufsize = QUERYSIZE;
- buf = alloca (bufsize);
+ size_t bufsize = (type == T_UNSPEC ? 2 : 1) * QUERYSIZE;
+ u_char *buf = alloca (bufsize);
+ u_char *query1 = buf;
+ int nquery1 = -1;
+ u_char *query2 = NULL;
+ int nquery2 = 0;
again:
hp->rcode = NOERROR; /* default */
@@ -133,18 +138,47 @@ __libc_res_nquery(res_state statp,
printf(";; res_query(%s, %d, %d)\n", name, class, type);
#endif
- n = res_nmkquery(statp, QUERY, name, class, type, NULL, 0, NULL,
- buf, bufsize);
- if (n > 0
- && (oflags & RES_F_EDNS0ERR) == 0
- && (statp->options & RES_USE_EDNS0) != 0)
- n = __res_nopt(statp, n, buf, bufsize, anslen);
+ if (type == T_UNSPEC)
+ {
+ n = res_nmkquery(statp, QUERY, name, class, T_A, NULL, 0, NULL,
+ query1, bufsize);
+ if (n > 0)
+ {
+ if ((oflags & RES_F_EDNS0ERR) == 0
+ && (statp->options & RES_USE_EDNS0) != 0)
+ n = __res_nopt(statp, n, query1, bufsize, anslen / 2);
+
+ nquery1 = n;
+ query2 = buf + nquery1;
+ n = res_nmkquery(statp, QUERY, name, class, T_AAAA, NULL, 0,
+ NULL, query2, bufsize - n);
+ if (n > 0
+ && (oflags & RES_F_EDNS0ERR) == 0
+ && (statp->options & RES_USE_EDNS0) != 0)
+ n = __res_nopt(statp, n, query2, bufsize - n, anslen / 2);
+ nquery2 = n;
+ }
+ }
+ else
+ {
+ n = res_nmkquery(statp, QUERY, name, class, type, NULL, 0, NULL,
+ query1, bufsize);
+
+ if (n > 0
+ && (oflags & RES_F_EDNS0ERR) == 0
+ && (statp->options & RES_USE_EDNS0) != 0)
+ n = __res_nopt(statp, n, query1, bufsize, anslen);
+
+ nquery1 = n;
+ }
+
if (__builtin_expect (n <= 0, 0) && !use_malloc) {
/* Retry just in case res_nmkquery failed because of too
short buffer. Shouldn't happen. */
- bufsize = MAXPACKET;
+ bufsize = (type == T_UNSPEC ? 2 : 1) * MAXPACKET;
buf = malloc (bufsize);
if (buf != NULL) {
+ query1 = buf;
use_malloc = 1;
goto again;
}
@@ -168,7 +202,8 @@ __libc_res_nquery(res_state statp,
return (n);
}
assert (answerp == NULL || (void *) *answerp == (void *) answer);
- n = __libc_res_nsend(statp, buf, n, answer, anslen, answerp);
+ n = __libc_res_nsend(statp, query1, nquery1, query2, nquery2, answer,
+ anslen, answerp, answerp2, nanswerp2);
if (use_malloc)
free (buf);
if (n < 0) {
@@ -184,20 +219,37 @@ __libc_res_nquery(res_state statp,
/* __libc_res_nsend might have reallocated the buffer. */
hp = (HEADER *) *answerp;
- if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
+ /* We simplify the following tests by assigning HP to HP2. It
+ is easy to verify that this is the same as ignoring all
+ tests of HP2. */
+ HEADER *hp2 = answerp2 ? (HEADER *) *answerp2 : hp;
+
+ if ((hp->rcode != NOERROR || ntohs(hp->ancount) == 0)
+ && (hp2->rcode != NOERROR || ntohs(hp2->ancount) == 0)) {
#ifdef DEBUG
- if (statp->options & RES_DEBUG)
+ if (statp->options & RES_DEBUG) {
printf(";; rcode = %d, ancount=%d\n", hp->rcode,
ntohs(hp->ancount));
+ if (hp != hp2)
+ printf(";; rcode2 = %d, ancount2=%d\n", hp2->rcode,
+ ntohs(hp2->ancount));
+ }
#endif
- switch (hp->rcode) {
+ switch (hp->rcode == NOERROR ? hp2->rcode : hp->rcode) {
case NXDOMAIN:
+ if ((hp->rcode == NOERROR && ntohs (hp->ancount) != 0)
+ || (hp2->rcode == NOERROR
+ && ntohs (hp2->ancount) != 0))
+ goto success;
RES_SET_H_ERRNO(statp, HOST_NOT_FOUND);
break;
case SERVFAIL:
RES_SET_H_ERRNO(statp, TRY_AGAIN);
break;
case NOERROR:
+ if (ntohs (hp->ancount) != 0
+ || ntohs (hp2->ancount) != 0)
+ goto success;
RES_SET_H_ERRNO(statp, NO_DATA);
break;
case FORMERR:
@@ -209,6 +261,7 @@ __libc_res_nquery(res_state statp,
}
return (-1);
}
+ success:
return (n);
}
libresolv_hidden_def (__libc_res_nquery)
@@ -221,7 +274,7 @@ res_nquery(res_state statp,
int anslen) /* size of answer buffer */
{
return __libc_res_nquery(statp, name, class, type, answer, anslen,
- NULL);
+ NULL, NULL, NULL);
}
libresolv_hidden_def (res_nquery)
@@ -233,11 +286,13 @@ libresolv_hidden_def (res_nquery)
*/
int
__libc_res_nsearch(res_state statp,
- const char *name, /* domain name */
- int class, int type, /* class and type of query */
- u_char *answer, /* buffer to put answer */
- int anslen, /* size of answer */
- u_char **answerp)
+ const char *name, /* domain name */
+ int class, int type, /* class and type of query */
+ u_char *answer, /* buffer to put answer */
+ int anslen, /* size of answer */
+ u_char **answerp,
+ u_char **answerp2,
+ int *nanswerp2)
{
const char *cp, * const *domain;
HEADER *hp = (HEADER *) answer;
@@ -260,7 +315,8 @@ __libc_res_nsearch(res_state statp,
/* If there aren't any dots, it could be a user-level alias. */
if (!dots && (cp = res_hostalias(statp, name, tmp, sizeof tmp))!= NULL)
return (__libc_res_nquery(statp, cp, class, type, answer,
- anslen, answerp));
+ anslen, answerp, answerp2,
+ nanswerp2));
#ifdef DEBUG
if (statp->options & RES_DEBUG)
@@ -276,7 +332,8 @@ __libc_res_nsearch(res_state statp,
saved_herrno = -1;
if (dots >= statp->ndots || trailing_dot) {
ret = __libc_res_nquerydomain(statp, name, NULL, class, type,
- answer, anslen, answerp);
+ answer, anslen, answerp,
+ answerp2, nanswerp2);
if (ret > 0 || trailing_dot)
return (ret);
saved_herrno = h_errno;
@@ -285,6 +342,12 @@ __libc_res_nsearch(res_state statp,
answer = *answerp;
anslen = MAXPACKET;
}
+ if (answerp2
+ && (*answerp2 < answer || *answerp2 >= answer + anslen))
+ {
+ free (*answerp2);
+ *answerp2 = NULL;
+ }
}
/*
@@ -307,7 +370,8 @@ __libc_res_nsearch(res_state statp,
ret = __libc_res_nquerydomain(statp, name, *domain,
class, type,
- answer, anslen, answerp);
+ answer, anslen, answerp,
+ answerp2, nanswerp2);
if (ret > 0)
return (ret);
@@ -315,6 +379,13 @@ __libc_res_nsearch(res_state statp,
answer = *answerp;
anslen = MAXPACKET;
}
+ if (answerp2
+ && (*answerp2 < answer
+ || *answerp2 >= answer + anslen))
+ {
+ free (*answerp2);
+ *answerp2 = NULL;
+ }
/*
* If no server present, give up.
@@ -368,7 +439,8 @@ __libc_res_nsearch(res_state statp,
*/
if (dots && !(tried_as_is || root_on_list)) {
ret = __libc_res_nquerydomain(statp, name, NULL, class, type,
- answer, anslen, answerp);
+ answer, anslen, answerp,
+ answerp2, nanswerp2);
if (ret > 0)
return (ret);
}
@@ -380,6 +452,11 @@ __libc_res_nsearch(res_state statp,
* else send back meaningless H_ERRNO, that being the one from
* the last DNSRCH we did.
*/
+ if (answerp2 && (*answerp2 < answer || *answerp2 >= answer + anslen))
+ {
+ free (*answerp2);
+ *answerp2 = NULL;
+ }
if (saved_herrno != -1)
RES_SET_H_ERRNO(statp, saved_herrno);
else if (got_nodata)
@@ -398,7 +475,7 @@ res_nsearch(res_state statp,
int anslen) /* size of answer */
{
return __libc_res_nsearch(statp, name, class, type, answer,
- anslen, NULL);
+ anslen, NULL, NULL, NULL);
}
libresolv_hidden_def (res_nsearch)
@@ -408,12 +485,14 @@ libresolv_hidden_def (res_nsearch)
*/
static int
__libc_res_nquerydomain(res_state statp,
- const char *name,
- const char *domain,
- int class, int type, /* class and type of query */
- u_char *answer, /* buffer to put answer */
- int anslen, /* size of answer */
- u_char **answerp)
+ const char *name,
+ const char *domain,
+ int class, int type, /* class and type of query */
+ u_char *answer, /* buffer to put answer */
+ int anslen, /* size of answer */
+ u_char **answerp,
+ u_char **answerp2,
+ int *nanswerp2)
{
char nbuf[MAXDNAME];
const char *longname = nbuf;
@@ -450,7 +529,7 @@ __libc_res_nquerydomain(res_state statp,
sprintf(nbuf, "%s.%s", name, domain);
}
return (__libc_res_nquery(statp, longname, class, type, answer,
- anslen, answerp));
+ anslen, answerp, answerp2, nanswerp2));
}
int
@@ -462,7 +541,7 @@ res_nquerydomain(res_state statp,
int anslen) /* size of answer */
{
return __libc_res_nquerydomain(statp, name, domain, class, type,
- answer, anslen, NULL);
+ answer, anslen, NULL, NULL, NULL);
}
libresolv_hidden_def (res_nquerydomain)
diff --git a/resolv/res_send.c b/resolv/res_send.c
index 23306a2..b3dbd70 100644
--- a/resolv/res_send.c
+++ b/resolv/res_send.c
@@ -176,10 +176,14 @@ evNowTime(struct timespec *res) {
/* Forward. */
static int send_vc(res_state, const u_char *, int,
- u_char **, int *, int *, int, u_char **);
+ const u_char *, int,
+ u_char **, int *, int *, int, u_char **,
+ u_char **, int *, int *);
static int send_dg(res_state, const u_char *, int,
+ const u_char *, int,
u_char **, int *, int *, int,
- int *, int *, u_char **);
+ int *, int *, u_char **,
+ u_char **, int *, int *);
#ifdef DEBUG
static void Aerror(const res_state, FILE *, const char *, int,
const struct sockaddr *);
@@ -334,33 +338,41 @@ libresolv_hidden_def (res_queriesmatch)
int
__libc_res_nsend(res_state statp, const u_char *buf, int buflen,
- u_char *ans, int anssiz, u_char **ansp)
+ const u_char *buf2, int buflen2,
+ u_char *ans, int anssiz, u_char **ansp, u_char **ansp2,
+ int *nansp2)
{
- int gotsomewhere, terrno, try, v_circuit, resplen, ns, n;
+ int gotsomewhere, terrno, try, v_circuit, resplen, resplen2, ns, n;
if (statp->nscount == 0) {
__set_errno (ESRCH);
return (-1);
}
- if (anssiz < HFIXEDSZ) {
+ if (anssiz < (buf2 == NULL ? 1 : 2) * HFIXEDSZ) {
__set_errno (EINVAL);
return (-1);
}
- if ((statp->qhook || statp->rhook) && anssiz < MAXPACKET && ansp) {
- u_char *buf = malloc (MAXPACKET);
- if (buf == NULL)
- return (-1);
- memcpy (buf, ans, HFIXEDSZ);
- *ansp = buf;
- ans = buf;
- anssiz = MAXPACKET;
+#ifdef USE_HOOKS
+ if (__builtin_expect (statp->qhook || statp->rhook, 0)) {
+ if (anssiz < MAXPACKET && ansp) {
+ u_char *buf = malloc (MAXPACKET);
+ if (buf == NULL)
+ return (-1);
+ memcpy (buf, ans, HFIXEDSZ);
+ *ansp = buf;
+ ans = buf;
+ anssiz = MAXPACKET;
+ }
}
+#endif
DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_QUERY),
(stdout, ";; res_send()\n"), buf, buflen);
- v_circuit = (statp->options & RES_USEVC) || buflen > PACKETSZ;
+ v_circuit = ((statp->options & RES_USEVC)
+ || buflen > PACKETSZ
+ || buflen2 > PACKETSZ);
gotsomewhere = 0;
terrno = ETIMEDOUT;
@@ -442,7 +454,7 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
* Some resolvers want to even out the load on their nameservers.
* Note that RES_BLAST overrides RES_ROTATE.
*/
- if ((statp->options & RES_ROTATE) != 0 &&
+ if (__builtin_expect ((statp->options & RES_ROTATE) != 0, 0) &&
(statp->options & RES_BLAST) == 0) {
struct sockaddr_in6 *ina;
unsigned int map;
@@ -479,8 +491,9 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
if (nsap == NULL)
goto next_ns;
- same_ns:
- if (statp->qhook) {
+ same_ns:
+#ifdef USE_HOOKS
+ if (__builtin_expect (statp->qhook != NULL, 0)) {
int done = 0, loops = 0;
do {
@@ -512,6 +525,7 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
}
} while (!done);
}
+#endif
#ifdef DEBUG
char tmpbuf[40];
@@ -521,29 +535,34 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
ns + 1, inet_ntop(AF_INET6, &nsap->sin6_addr,
tmpbuf, sizeof (tmpbuf))));
- if (v_circuit) {
+ if (__builtin_expect (v_circuit, 0)) {
/* Use VC; at most one attempt per server. */
try = statp->retry;
- n = send_vc(statp, buf, buflen, &ans, &anssiz, &terrno,
- ns, ansp);
+ n = send_vc(statp, buf, buflen, buf2, buflen2,
+ &ans, &anssiz, &terrno,
+ ns, ansp, ansp2, nansp2, &resplen2);
if (n < 0)
return (-1);
if (n == 0)
goto next_ns;
- resplen = n;
} else {
/* Use datagrams. */
- n = send_dg(statp, buf, buflen, &ans, &anssiz, &terrno,
- ns, &v_circuit, &gotsomewhere, ansp);
+ n = send_dg(statp, buf, buflen, buf2, buflen2,
+ &ans, &anssiz, &terrno,
+ ns, &v_circuit, &gotsomewhere, ansp,
+ ansp2, nansp2, &resplen2);
if (n < 0)
return (-1);
if (n == 0)
goto next_ns;
if (v_circuit)
+ // XXX Check whether both requests failed or
+ // XXX whether one have been answered successfully
goto same_ns;
- resplen = n;
}
+ resplen = n;
+
Dprint((statp->options & RES_DEBUG) ||
((statp->pfcode & RES_PRF_REPLY) &&
(statp->pfcode & RES_PRF_HEAD1)),
@@ -553,6 +572,11 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
(statp->pfcode & RES_PRF_REPLY),
(stdout, "%s", ""),
ans, (resplen > anssiz) ? anssiz : resplen);
+ if (buf2 != NULL)
+ DprintQ((statp->options & RES_DEBUG) ||
+ (statp->pfcode & RES_PRF_REPLY),
+ (stdout, "%s", ""),
+ *ansp2, (resplen2 > *nansp2) ? *nansp2 : resplen2);
/*
* If we have temporarily opened a virtual circuit,
@@ -563,7 +587,8 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
(statp->options & RES_STAYOPEN) == 0) {
__res_iclose(statp, false);
}
- if (statp->rhook) {
+#ifdef USE_HOOKS
+ if (__builtin_expect (statp->rhook, 0)) {
int done = 0, loops = 0;
do {
@@ -593,6 +618,7 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
} while (!done);
}
+#endif
return (resplen);
next_ns: ;
} /*foreach ns*/
@@ -612,7 +638,8 @@ int
res_nsend(res_state statp,
const u_char *buf, int buflen, u_char *ans, int anssiz)
{
- return __libc_res_nsend(statp, buf, buflen, ans, anssiz, NULL);
+ return __libc_res_nsend(statp, buf, buflen, NULL, 0, ans, anssiz,
+ NULL, NULL, NULL);
}
libresolv_hidden_def (res_nsend)
@@ -620,17 +647,23 @@ libresolv_hidden_def (res_nsend)
static int
send_vc(res_state statp,
- const u_char *buf, int buflen, u_char **ansp, int *anssizp,
- int *terrno, int ns, u_char **anscp)
+ const u_char *buf, int buflen, const u_char *buf2, int buflen2,
+ u_char **ansp, int *anssizp,
+ int *terrno, int ns, u_char **anscp, u_char **ansp2, int *anssizp2,
+ int *resplen2)
{
const HEADER *hp = (HEADER *) buf;
+ const HEADER *hp2 = (HEADER *) buf2;
u_char *ans = *ansp;
- int anssiz = *anssizp;
+ int orig_anssizp = *anssizp;
+ // XXX REMOVE
+ // int anssiz = *anssizp;
HEADER *anhp = (HEADER *) ans;
struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns];
int truncating, connreset, resplen, n;
- struct iovec iov[2];
+ struct iovec iov[4];
u_short len;
+ u_short len2;
u_char *cp;
connreset = 0;
@@ -677,11 +710,19 @@ send_vc(res_state statp,
/*
* Send length & message
*/
- ns_put16((u_short)buflen, (u_char*)&len);
+ len = htons ((u_short) buflen);
evConsIovec(&len, INT16SZ, &iov[0]);
evConsIovec((void*)buf, buflen, &iov[1]);
- if (TEMP_FAILURE_RETRY (writev(statp->_vcsock, iov, 2))
- != (INT16SZ + buflen)) {
+ int niov = 2;
+ ssize_t explen = INT16SZ + buflen;
+ if (buf2 != NULL) {
+ len2 = htons ((u_short) buflen2);
+ evConsIovec(&len2, INT16SZ, &iov[2]);
+ evConsIovec((void*)buf2, buflen2, &iov[3]);
+ niov = 4;
+ explen += INT16SZ + buflen2;
+ }
+ if (TEMP_FAILURE_RETRY (writev(statp->_vcsock, iov, niov)) != explen) {
*terrno = errno;
Perror(statp, stderr, "write failed", errno);
__res_iclose(statp, false);
@@ -690,6 +731,8 @@ send_vc(res_state statp,
/*
* Receive length & response
*/
+ int recvresp1 = 0;
+ int recvresp2 = buf2 == NULL;
read_len:
cp = ans;
len = INT16SZ;
@@ -718,30 +761,66 @@ send_vc(res_state statp,
}
return (0);
}
+#ifdef _STRING_ARCH_unaligned
+ resplen = ntohs (*(uint16_t *) ans);
+#else
resplen = ns_get16(ans);
- if (resplen > anssiz) {
+#endif
+
+ int *thisanssizp;
+ u_char **thisansp;
+ int *thisresplenp;
+ if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) {
+ thisanssizp = anssizp;
+ thisansp = anscp ?: ansp;
+ assert (anscp != NULL || ansp2 == NULL);
+ thisresplenp = &resplen;
+ } else {
+ if (*anssizp != MAXPACKET) {
+ /* No buffer allocated for the first
+ reply. We can try to use the rest
+ of the user-provided buffer. */
+ *anssizp2 = orig_anssizp - resplen;
+ *ansp2 = *ansp + resplen;
+ } else {
+ /* The first reply did not fit into the
+ user-provided buffer. Maybe the second
+ answer will. */
+ *anssizp2 = orig_anssizp;
+ *ansp2 = *ansp;
+ }
+
+ thisanssizp = anssizp2;
+ thisansp = ansp2;
+ thisresplenp = resplen2;
+ }
+ anhp = (HEADER *) *thisansp;
+
+ *thisresplenp = resplen;
+ if (resplen > *thisanssizp) {
+ /* Yes, we test ANSCP here. If we have two buffers
+ both will be allocatable. */
if (anscp) {
- ans = malloc (MAXPACKET);
- if (ans == NULL) {
+ u_char *newp = malloc (MAXPACKET);
+ if (newp == NULL) {
*terrno = ENOMEM;
__res_iclose(statp, false);
return (0);
}
- anssiz = MAXPACKET;
- *anssizp = MAXPACKET;
- *ansp = ans;
- *anscp = ans;
- anhp = (HEADER *) ans;
+ *thisanssizp = MAXPACKET;
+ *thisansp = newp;
+ anhp = (HEADER *) newp;
len = resplen;
} else {
Dprint(statp->options & RES_DEBUG,
(stdout, ";; response truncated\n")
);
truncating = 1;
- len = anssiz;
+ len = *thisanssizp;
}
} else
len = resplen;
+
if (len < HFIXEDSZ) {
/*
* Undersized message.
@@ -752,7 +831,8 @@ send_vc(res_state statp,
__res_iclose(statp, false);
return (0);
}
- cp = ans;
+
+ cp = *thisansp;
while (len != 0 && (n = read(statp->_vcsock, (char *)cp, (int)len)) > 0){
cp += n;
len -= n;
@@ -768,7 +848,7 @@ send_vc(res_state statp,
* Flush rest of answer so connection stays in synch.
*/
anhp->tc = 1;
- len = resplen - anssiz;
+ len = resplen - *thisanssizp;
while (len != 0) {
char junk[PACKETSZ];
@@ -787,14 +867,25 @@ send_vc(res_state statp,
* itself confused, then drop the packet and
* wait for the correct one.
*/
- if (hp->id != anhp->id) {
+ if ((recvresp1 || hp->id != anhp->id)
+ && (recvresp2 || hp2->id != anhp->id)) {
DprintQ((statp->options & RES_DEBUG) ||
(statp->pfcode & RES_PRF_REPLY),
(stdout, ";; old answer (unexpected):\n"),
- ans, (resplen > anssiz) ? anssiz: resplen);
+ *thisansp,
+ (resplen > *thisanssiz) ? *thisanssiz: resplen);
goto read_len;
}
+ /* Mark which reply we received. */
+ if (recvresp1 == 0 && hp->id == anhp->id)
+ recvresp1 = 1;
+ else
+ recvresp2 = 1;
+ /* Repeat waiting if we have a second answer to arrive. */
+ if ((recvresp1 & recvresp2) == 0)
+ goto read_len;
+
/*
* All is well, or the error is fatal. Signal that the
* next nameserver ought not be tried.
@@ -804,19 +895,20 @@ send_vc(res_state statp,
static int
send_dg(res_state statp,
- const u_char *buf, int buflen, u_char **ansp, int *anssizp,
- int *terrno, int ns, int *v_circuit, int *gotsomewhere, u_char **anscp)
+ const u_char *buf, int buflen, const u_char *buf2, int buflen2,
+ u_char **ansp, int *anssizp,
+ int *terrno, int ns, int *v_circuit, int *gotsomewhere, u_char **anscp,
+ u_char **ansp2, int *anssizp2, int *resplen2)
{
const HEADER *hp = (HEADER *) buf;
+ const HEADER *hp2 = (HEADER *) buf2;
u_char *ans = *ansp;
- int anssiz = *anssizp;
- HEADER *anhp = (HEADER *) ans;
+ int orig_anssizp = *anssizp;
struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns];
struct timespec now, timeout, finish;
struct pollfd pfd[1];
int ptimeout;
struct sockaddr_in6 from;
- socklen_t fromlen;
int resplen, seconds, n;
if (EXT(statp).nssocks[ns] == -1) {
@@ -879,6 +971,8 @@ send_dg(res_state statp,
evAddTime(&finish, &now, &timeout);
int need_recompute = 0;
int nwritten = 0;
+ int recvresp1 = 0;
+ int recvresp2 = buf2 == NULL;
pfd[0].fd = EXT(statp).nssocks[ns];
pfd[0].events = POLLOUT;
wait:
@@ -918,35 +1012,73 @@ send_dg(res_state statp,
}
__set_errno (0);
if (pfd[0].revents & POLLOUT) {
- if (send (pfd[0].fd, buf, buflen, MSG_NOSIGNAL) != buflen) {
+ ssize_t sr;
+ if (nwritten != 0)
+ sr = send (pfd[0].fd, buf2, buflen2, MSG_NOSIGNAL);
+ else
+ sr = send (pfd[0].fd, buf, buflen, MSG_NOSIGNAL);
+
+ if (sr != buflen) {
if (errno == EINTR || errno == EAGAIN)
goto recompute_resend;
Perror(statp, stderr, "send", errno);
goto err_out;
}
- pfd[0].events = POLLIN;
+ if (nwritten != 0 || buf2 == NULL)
+ pfd[0].events = POLLIN;
+ else
+ pfd[0].events = POLLIN | POLLOUT;
++nwritten;
goto wait;
} else if (pfd[0].revents & POLLIN) {
- fromlen = sizeof(struct sockaddr_in6);
- if (anssiz < MAXPACKET
+ int *thisanssizp;
+ u_char **thisansp;
+ int *thisresplenp;
+
+ if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) {
+ thisanssizp = anssizp;
+ thisansp = anscp ?: ansp;
+ assert (anscp != NULL || ansp2 == NULL);
+ thisresplenp = &resplen;
+ } else {
+ if (*anssizp != MAXPACKET) {
+ /* No buffer allocated for the first
+ reply. We can try to use the rest
+ of the user-provided buffer. */
+ *anssizp2 = orig_anssizp - resplen;
+ *ansp2 = *ansp + resplen;
+ } else {
+ /* The first reply did not fit into the
+ user-provided buffer. Maybe the second
+ answer will. */
+ *anssizp2 = orig_anssizp;
+ *ansp2 = *ansp;
+ }
+
+ thisanssizp = anssizp2;
+ thisansp = ansp2;
+ thisresplenp = resplen2;
+ }
+
+ if (*thisanssizp < MAXPACKET
+ /* Yes, we test ANSCP here. If we have two buffers
+ both will be allocatable. */
&& anscp
- && (ioctl (pfd[0].fd, FIONREAD, &resplen) < 0
- || anssiz < resplen)) {
- ans = malloc (MAXPACKET);
- if (ans == NULL)
- ans = *ansp;
- else {
- anssiz = MAXPACKET;
+ && (ioctl (pfd[0].fd, FIONREAD, thisresplenp) < 0
+ || *thisanssizp < *thisresplenp)) {
+ u_char *newp = malloc (MAXPACKET);
+ if (newp != NULL) {
*anssizp = MAXPACKET;
- *ansp = ans;
- *anscp = ans;
- anhp = (HEADER *) ans;
+ *thisansp = ans = newp;
}
}
- resplen = recvfrom(pfd[0].fd, (char*)ans, anssiz,0,
- (struct sockaddr *)&from, &fromlen);
- if (resplen <= 0) {
+ HEADER *anhp = (HEADER *) *thisansp;
+ socklen_t fromlen = sizeof(struct sockaddr_in6);
+ assert (sizeof(from) <= fromlen);
+ *thisresplenp = recvfrom(pfd[0].fd, (char*)*thisansp,
+ *thisanssizp, 0,
+ (struct sockaddr *)&from, &fromlen);
+ if (*thisresplenp <= 0) {
if (errno == EINTR || errno == EAGAIN) {
need_recompute = 1;
goto wait;
@@ -955,17 +1087,18 @@ send_dg(res_state statp,
goto err_out;
}
*gotsomewhere = 1;
- if (resplen < HFIXEDSZ) {
+ if (*thisresplenp < HFIXEDSZ) {
/*
* Undersized message.
*/
Dprint(statp->options & RES_DEBUG,
(stdout, ";; undersized: %d\n",
- resplen));
+ *thisresplen));
*terrno = EMSGSIZE;
goto err_out;
}
- if (hp->id != anhp->id) {
+ if ((recvresp1 || hp->id != anhp->id)
+ && (recvresp2 || hp2->id != anhp->id)) {
/*
* response from old query, ignore it.
* XXX - potential security hazard could
@@ -974,7 +1107,9 @@ send_dg(res_state statp,
DprintQ((statp->options & RES_DEBUG) ||
(statp->pfcode & RES_PRF_REPLY),
(stdout, ";; old answer:\n"),
- ans, (resplen > anssiz) ? anssiz : resplen);
+ thisansp,
+ (*thisresplen > *thisanssiz)
+ ? *thisanssiz : *thisresplen);
goto wait;
}
if (!(statp->options & RES_INSECURE1) &&
@@ -987,14 +1122,16 @@ send_dg(res_state statp,
DprintQ((statp->options & RES_DEBUG) ||
(statp->pfcode & RES_PRF_REPLY),
(stdout, ";; not our server:\n"),
- ans, (resplen > anssiz) ? anssiz : resplen);
+ thisansp,
+ (*thisresplen > *thisanssiz)
+ ? *thisanssiz : *thisresplen);
goto wait;
}
#ifdef RES_USE_EDNS0
if (anhp->rcode == FORMERR
&& (statp->options & RES_USE_EDNS0) != 0U) {
/*
- * Do not retry if the server do not understand
+ * Do not retry if the server does not understand
* EDNS0. The case has to be captured here, as
* FORMERR packet do not carry query section, hence
* res_queriesmatch() returns 0.
@@ -1002,15 +1139,23 @@ send_dg(res_state statp,
DprintQ(statp->options & RES_DEBUG,
(stdout,
"server rejected query with EDNS0:\n"),
- ans, (resplen > anssiz) ? anssiz : resplen);
+ thisans,
+ (*thisresplen > *thisanssiz)
+ ? *thisanssiz : *thisresplen);
/* record the error */
statp->_flags |= RES_F_EDNS0ERR;
goto err_out;
}
#endif
- if (!(statp->options & RES_INSECURE2) &&
- !res_queriesmatch(buf, buf + buflen,
- ans, ans + anssiz)) {
+ if (!(statp->options & RES_INSECURE2)
+ && (recvresp1 || !res_queriesmatch(buf, buf + buflen,
+ *thisansp,
+ *thisansp
+ + *thisanssizp))
+ && (recvresp2 || !res_queriesmatch(buf2, buf2 + buflen2,
+ *thisansp,
+ *thisansp
+ + *thisanssizp))) {
/*
* response contains wrong query? ignore it.
* XXX - potential security hazard could
@@ -1019,7 +1164,9 @@ send_dg(res_state statp,
DprintQ((statp->options & RES_DEBUG) ||
(statp->pfcode & RES_PRF_REPLY),
(stdout, ";; wrong query name:\n"),
- ans, (resplen > anssiz) ? anssiz : resplen);
+ thisansp,
+ (*thisresplen > *thisanssiz)
+ ? *thisanssiz : *thisresplen);
goto wait;
}
if (anhp->rcode == SERVFAIL ||
@@ -1027,7 +1174,9 @@ send_dg(res_state statp,
anhp->rcode == REFUSED) {
DprintQ(statp->options & RES_DEBUG,
(stdout, "server rejected query:\n"),
- ans, (resplen > anssiz) ? anssiz : resplen);
+ thisansp,
+ (*thisresplen > *thisanssiz)
+ ? *thisanssiz : *thisresplen);
next_ns:
__res_iclose(statp, false);
/* don't retry if called from dig */
@@ -1038,7 +1187,9 @@ send_dg(res_state statp,
&& anhp->aa == 0 && anhp->ra == 0 && anhp->arcount == 0) {
DprintQ(statp->options & RES_DEBUG,
(stdout, "referred query:\n"),
- ans, (resplen > anssiz) ? anssiz : resplen);
+ thisansp,
+ (*thisresplen > *thisanssiz)
+ ? *thisanssiz : *thisresplen);
goto next_ns;
}
if (!(statp->options & RES_IGNTC) && anhp->tc) {
@@ -1050,8 +1201,18 @@ send_dg(res_state statp,
(stdout, ";; truncated answer\n"));
*v_circuit = 1;
__res_iclose(statp, false);
+ // XXX if we have received one reply we could
+ // XXX use it and not repeat it over TCP...
return (1);
}
+ /* Mark which reply we received. */
+ if (recvresp1 == 0 && hp->id == anhp->id)
+ recvresp1 = 1;
+ else
+ recvresp2 = 1;
+ /* Repeat waiting if we have a second answer to arrive. */
+ if ((recvresp1 & recvresp2) == 0)
+ goto wait;
/*
* All is well, or the error is fatal. Signal that the
* next nameserver ought not be tried.