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glibc/resolv-nameserver-handling.patch
Andreas Schwab 797ff301f4 Accepting request 287683 from home:Andreas_Schwab:Factory 
- resolv-nameserver-handling.patch: Rewrite handling of nameserver
  configuration in resolver

OBS-URL: https://build.opensuse.org/request/show/287683
OBS-URL: https://build.opensuse.org/package/show/Base:System/glibc?expand=0&rev=394
2015-02-25 10:57:57 +00:00

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From 0872db85cda0f4d3d1772f365732731f2c0a3c3c Mon Sep 17 00:00:00 2001
From: Andreas Schwab <schwab@suse.de>
Date: Thu, 19 Feb 2015 15:52:08 +0100
Subject: [PATCH] Rewrite handling of nameserver configuration in resolver
[BZ #13028]
[BZ #17053]
* resolv/res_private.h: New file.
* resolv/resolv.h (struct __res_state): Add pointer to struct
__res_state_ext member, rename ext.nsmap, ext.nscount6,
ext.nsinit, ext.nsaddrs members to __glibc_reserved*.
* resolv/res_init.c (__res_vinit): Rewrite handling of nameserver
addresses.
(__res_iclose): Deallocate __res_state_ext memory if free_addr.
* resolv/res_send.c (__libc_res_nsend): Rewrite nameserver setup.
(get_nsaddr): New function.
(res_ourserver_p, send_vc, reopen): Use it instead of accessing
statp directly.
---
resolv/res_init.c | 125 +++++++++++++++---------------------
resolv/res_private.h | 29 +++++++++
resolv/res_send.c | 176 ++++++++++++++++++++++-----------------------------
resolv/resolv.h | 9 +--
4 files changed, 160 insertions(+), 179 deletions(-)
create mode 100644 resolv/res_private.h
diff --git a/resolv/res_init.c b/resolv/res_init.c
index 553ba12..567afaa 100644
--- a/resolv/res_init.c
+++ b/resolv/res_init.c
@@ -89,6 +89,8 @@ static const char rcsid[] = "$BINDId: res_init.c,v 8.16 2000/05/09 07:10:12 vixi
#include <not-cancel.h>
+#include "res_private.h"
+
/* Options. Should all be left alone. */
#define RESOLVSORT
#define RFC1535
@@ -153,10 +155,8 @@ __res_vinit(res_state statp, int preinit) {
char *cp, **pp;
int n;
char buf[BUFSIZ];
- int nserv = 0; /* number of IPv4 nameservers read from file */
-#ifdef _LIBC
- int nservall = 0; /* number of (IPv4 + IPV6) nameservers read from file */
-#endif
+ int nserv = 0; /* number of nameservers read from file */
+ int have_serv6 = 0;
int haveenv = 0;
int havesearch = 0;
#ifdef RESOLVSORT
@@ -184,15 +184,12 @@ __res_vinit(res_state statp, int preinit) {
statp->_flags = 0;
statp->qhook = NULL;
statp->rhook = NULL;
- statp->_u._ext.nsinit = 0;
statp->_u._ext.nscount = 0;
-#ifdef _LIBC
- statp->_u._ext.nscount6 = 0;
- for (n = 0; n < MAXNS; n++) {
- statp->_u._ext.nsaddrs[n] = NULL;
- statp->_u._ext.nsmap[n] = MAXNS;
+ if (statp->_u._ext.ext == NULL) {
+ statp->_u._ext.ext = malloc (sizeof (*statp->_u._ext.ext));
+ if (statp->_u._ext.ext != NULL)
+ memset (statp->_u._ext.ext, 0, sizeof (*statp->_u._ext.ext));
}
-#endif
/* Allow user to override the local domain definition */
if ((cp = getenv("LOCALDOMAIN")) != NULL) {
@@ -296,11 +293,7 @@ __res_vinit(res_state statp, int preinit) {
continue;
}
/* read nameservers to query */
-#ifdef _LIBC
- if (MATCH(buf, "nameserver") && nservall < MAXNS) {
-#else
if (MATCH(buf, "nameserver") && nserv < MAXNS) {
-#endif
struct in_addr a;
cp = buf + sizeof("nameserver") - 1;
@@ -308,13 +301,11 @@ __res_vinit(res_state statp, int preinit) {
cp++;
if ((*cp != '\0') && (*cp != '\n')
&& __inet_aton(cp, &a)) {
- statp->nsaddr_list[nservall].sin_addr = a;
- statp->nsaddr_list[nservall].sin_family = AF_INET;
- statp->nsaddr_list[nservall].sin_port =
+ statp->nsaddr_list[nserv].sin_addr = a;
+ statp->nsaddr_list[nserv].sin_family = AF_INET;
+ statp->nsaddr_list[nserv].sin_port =
htons(NAMESERVER_PORT);
nserv++;
-#ifdef _LIBC
- nservall++;
} else {
struct in6_addr a6;
char *el;
@@ -324,45 +315,40 @@ __res_vinit(res_state statp, int preinit) {
if ((el = strchr(cp, SCOPE_DELIMITER)) != NULL)
*el = '\0';
if ((*cp != '\0') &&
- (__inet_pton(AF_INET6, cp, &a6) > 0)) {
- struct sockaddr_in6 *sa6;
-
- sa6 = malloc(sizeof(*sa6));
- if (sa6 != NULL) {
- sa6->sin6_family = AF_INET6;
- sa6->sin6_port = htons(NAMESERVER_PORT);
- sa6->sin6_flowinfo = 0;
- sa6->sin6_addr = a6;
-
- if (__glibc_likely (el == NULL))
- sa6->sin6_scope_id = 0;
- else {
- int try_numericscope = 1;
- if (IN6_IS_ADDR_LINKLOCAL (&a6)
- || IN6_IS_ADDR_MC_LINKLOCAL (&a6)) {
- sa6->sin6_scope_id
- = __if_nametoindex (el + 1);
- if (sa6->sin6_scope_id != 0)
- try_numericscope = 0;
- }
-
- if (try_numericscope) {
- char *end;
- sa6->sin6_scope_id
- = (uint32_t) strtoul (el + 1, &end,
- 10);
- if (*end != '\0')
- sa6->sin6_scope_id = 0;
- }
+ (__inet_pton(AF_INET6, cp, &a6) > 0)
+ && statp->_u._ext.ext != NULL) {
+ struct sockaddr_in6 *sa6
+ = &statp->_u._ext.ext->nsaddrs[nserv].sin6;
+
+ sa6->sin6_family = AF_INET6;
+ sa6->sin6_port = htons(NAMESERVER_PORT);
+ sa6->sin6_flowinfo = 0;
+ sa6->sin6_addr = a6;
+
+ if (__glibc_likely (el == NULL))
+ sa6->sin6_scope_id = 0;
+ else {
+ int try_numericscope = 1;
+ if (IN6_IS_ADDR_LINKLOCAL (&a6)
+ || IN6_IS_ADDR_MC_LINKLOCAL (&a6)) {
+ sa6->sin6_scope_id
+ = __if_nametoindex (el + 1);
+ if (sa6->sin6_scope_id != 0)
+ try_numericscope = 0;
}
- statp->_u._ext.nsaddrs[nservall] = sa6;
- statp->_u._ext.nssocks[nservall] = -1;
- statp->_u._ext.nsmap[nservall] = MAXNS + 1;
- nservall++;
+ if (try_numericscope) {
+ char *end;
+ sa6->sin6_scope_id
+ = (uint32_t) strtoul (el + 1, &end, 10);
+ if (*end != '\0')
+ sa6->sin6_scope_id = 0;
+ }
}
+ statp->nsaddr_list[nserv].sin_family = 0;
+ have_serv6 = 1;
+ nserv++;
}
-#endif
}
continue;
}
@@ -414,10 +400,9 @@ __res_vinit(res_state statp, int preinit) {
continue;
}
}
- statp->nscount = nservall;
+ statp->nscount = nserv;
#ifdef _LIBC
- if (nservall - nserv > 0) {
- statp->_u._ext.nscount6 = nservall - nserv;
+ if (have_serv6) {
/* We try IPv6 servers again. */
statp->ipv6_unavail = false;
}
@@ -606,23 +591,15 @@ __res_iclose(res_state statp, bool free_addr) {
statp->_vcsock = -1;
statp->_flags &= ~(RES_F_VC | RES_F_CONN);
}
-#ifdef _LIBC
- for (ns = 0; ns < MAXNS; ns++)
-#else
- for (ns = 0; ns < statp->_u._ext.nscount; ns++)
-#endif
- if (statp->_u._ext.nsaddrs[ns]) {
- if (statp->_u._ext.nssocks[ns] != -1) {
- close_not_cancel_no_status(statp->_u._ext.nssocks[ns]);
- statp->_u._ext.nssocks[ns] = -1;
- }
- if (free_addr) {
- free (statp->_u._ext.nsaddrs[ns]);
- statp->_u._ext.nsaddrs[ns] = NULL;
- }
+ for (ns = 0; ns < statp->nscount; ns++)
+ if (statp->_u._ext.nssocks[ns] != -1) {
+ close_not_cancel_no_status(statp->_u._ext.nssocks[ns]);
+ statp->_u._ext.nssocks[ns] = -1;
}
- if (free_addr)
- statp->_u._ext.nsinit = 0;
+ if (free_addr) {
+ free (statp->_u._ext.ext);
+ statp->_u._ext.ext = NULL;
+ }
}
libc_hidden_def (__res_iclose)
diff --git a/resolv/res_private.h b/resolv/res_private.h
new file mode 100644
index 0000000..deb495b
--- /dev/null
+++ b/resolv/res_private.h
@@ -0,0 +1,29 @@
+/* Private definitions for the stub resolver.
+ Copyright (C) 2015 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+union res_sockaddr_union
+{
+ struct sockaddr s;
+ struct sockaddr_in sin;
+ struct sockaddr_in6 sin6;
+};
+
+struct __res_state_ext
+{
+ union res_sockaddr_union nsaddrs[MAXNS];
+};
diff --git a/resolv/res_send.c b/resolv/res_send.c
index c35fb66..1e6d217 100644
--- a/resolv/res_send.c
+++ b/resolv/res_send.c
@@ -179,11 +179,13 @@ evNowTime(struct timespec *res) {
/* Options. Leave them on. */
/* #undef DEBUG */
#include "res_debug.h"
+#include "res_private.h"
#define EXT(res) ((res)->_u._ext)
/* Forward. */
+static struct sockaddr *get_nsaddr (res_state, int);
static int send_vc(res_state, const u_char *, int,
const u_char *, int,
u_char **, int *, int *, int, u_char **,
@@ -221,20 +223,21 @@ res_ourserver_p(const res_state statp, const struct sockaddr_in6 *inp)
in_port_t port = in4p->sin_port;
in_addr_t addr = in4p->sin_addr.s_addr;
- for (ns = 0; ns < MAXNS; ns++) {
+ for (ns = 0; ns < statp->nscount; ns++) {
const struct sockaddr_in *srv =
- (struct sockaddr_in *)EXT(statp).nsaddrs[ns];
+ (struct sockaddr_in *) get_nsaddr (statp, ns);
- if ((srv != NULL) && (srv->sin_family == AF_INET) &&
+ if ((srv->sin_family == AF_INET) &&
(srv->sin_port == port) &&
(srv->sin_addr.s_addr == INADDR_ANY ||
srv->sin_addr.s_addr == addr))
return (1);
}
} else if (inp->sin6_family == AF_INET6) {
- for (ns = 0; ns < MAXNS; ns++) {
- const struct sockaddr_in6 *srv = EXT(statp).nsaddrs[ns];
- if ((srv != NULL) && (srv->sin6_family == AF_INET6) &&
+ for (ns = 0; ns < statp->nscount; ns++) {
+ const struct sockaddr_in6 *srv
+ = (struct sockaddr_in6 *) get_nsaddr (statp, ns);
+ if ((srv->sin6_family == AF_INET6) &&
(srv->sin6_port == inp->sin6_port) &&
!(memcmp(&srv->sin6_addr, &in6addr_any,
sizeof (struct in6_addr)) &&
@@ -384,80 +387,40 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
* If the ns_addr_list in the resolver context has changed, then
* invalidate our cached copy and the associated timing data.
*/
- if (EXT(statp).nsinit) {
+ if (EXT(statp).nscount != 0) {
int needclose = 0;
if (EXT(statp).nscount != statp->nscount)
needclose++;
else
- for (ns = 0; ns < MAXNS; ns++) {
- unsigned int map = EXT(statp).nsmap[ns];
- if (map < MAXNS
+ for (ns = 0; ns < statp->nscount; ns++) {
+ if (statp->nsaddr_list[ns].sin_family != 0
&& !sock_eq((struct sockaddr_in6 *)
- &statp->nsaddr_list[map],
- EXT(statp).nsaddrs[ns]))
+ &statp->nsaddr_list[ns],
+ &EXT(statp).ext->nsaddrs[ns].sin6))
{
needclose++;
break;
}
}
- if (needclose)
+ if (needclose) {
__res_iclose(statp, false);
+ EXT(statp).nscount = 0;
+ }
}
/*
* Maybe initialize our private copy of the ns_addr_list.
*/
- if (EXT(statp).nsinit == 0) {
- unsigned char map[MAXNS];
-
- memset (map, MAXNS, sizeof (map));
- for (n = 0; n < MAXNS; n++) {
- ns = EXT(statp).nsmap[n];
- if (ns < statp->nscount)
- map[ns] = n;
- else if (ns < MAXNS) {
- free(EXT(statp).nsaddrs[n]);
- EXT(statp).nsaddrs[n] = NULL;
- EXT(statp).nsmap[n] = MAXNS;
- }
+ if (EXT(statp).nscount == 0) {
+ for (ns = 0; ns < statp->nscount; ns++) {
+ EXT(statp).nssocks[ns] = -1;
+ if (statp->nsaddr_list[ns].sin_family != 0
+ && EXT(statp).ext != NULL)
+ EXT(statp).ext->nsaddrs[ns].sin
+ = statp->nsaddr_list[ns];
}
- n = statp->nscount;
- if (statp->nscount > EXT(statp).nscount)
- for (n = EXT(statp).nscount, ns = 0;
- n < statp->nscount; n++) {
- while (ns < MAXNS
- && EXT(statp).nsmap[ns] != MAXNS)
- ns++;
- if (ns == MAXNS)
- break;
- /* NS never exceeds MAXNS, but gcc 4.9 somehow
- does not see this. */
- DIAG_PUSH_NEEDS_COMMENT;
- DIAG_IGNORE_NEEDS_COMMENT (4.9,
- "-Warray-bounds");
- EXT(statp).nsmap[ns] = n;
- DIAG_POP_NEEDS_COMMENT;
- map[n] = ns++;
- }
- EXT(statp).nscount = n;
- for (ns = 0; ns < EXT(statp).nscount; ns++) {
- n = map[ns];
- if (EXT(statp).nsaddrs[n] == NULL)
- EXT(statp).nsaddrs[n] =
- malloc(sizeof (struct sockaddr_in6));
- if (EXT(statp).nsaddrs[n] != NULL) {
- memset (mempcpy(EXT(statp).nsaddrs[n],
- &statp->nsaddr_list[ns],
- sizeof (struct sockaddr_in)),
- '\0',
- sizeof (struct sockaddr_in6)
- - sizeof (struct sockaddr_in));
- EXT(statp).nssocks[n] = -1;
- n++;
- }
- }
- EXT(statp).nsinit = 1;
+ EXT(statp).nscount = statp->nscount;
}
/*
@@ -466,44 +429,41 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
*/
if (__builtin_expect ((statp->options & RES_ROTATE) != 0, 0) &&
(statp->options & RES_BLAST) == 0) {
- struct sockaddr_in6 *ina;
- unsigned int map;
-
- n = 0;
- while (n < MAXNS && EXT(statp).nsmap[n] == MAXNS)
- n++;
- if (n < MAXNS) {
- ina = EXT(statp).nsaddrs[n];
- map = EXT(statp).nsmap[n];
- for (;;) {
- ns = n + 1;
- while (ns < MAXNS
- && EXT(statp).nsmap[ns] == MAXNS)
- ns++;
- if (ns == MAXNS)
- break;
- EXT(statp).nsaddrs[n] = EXT(statp).nsaddrs[ns];
- EXT(statp).nsmap[n] = EXT(statp).nsmap[ns];
- n = ns;
- }
- EXT(statp).nsaddrs[n] = ina;
- EXT(statp).nsmap[n] = map;
+ union res_sockaddr_union inu;
+ struct sockaddr_in ina;
+ int lastns = statp->nscount - 1;
+ int fd;
+
+ if (EXT(statp).ext != NULL)
+ inu = EXT(statp).ext->nsaddrs[0];
+ ina = statp->nsaddr_list[0];
+ fd = EXT(statp).nssocks[0];
+ for (ns = 0; ns < lastns; ns++) {
+ if (EXT(statp).ext != NULL)
+ EXT(statp).ext->nsaddrs[ns]
+ = EXT(statp).ext->nsaddrs[ns + 1];
+ statp->nsaddr_list[ns] = statp->nsaddr_list[ns + 1];
+ EXT(statp).nssocks[ns] = EXT(statp).nssocks[ns + 1];
}
+ if (EXT(statp).ext != NULL)
+ EXT(statp).ext->nsaddrs[lastns] = inu;
+ statp->nsaddr_list[lastns] = ina;
+ EXT(statp).nssocks[lastns] = fd;
}
/*
* Send request, RETRY times, or until successful.
*/
for (try = 0; try < statp->retry; try++) {
- for (ns = 0; ns < MAXNS; ns++)
+ for (ns = 0; ns < statp->nscount; ns++)
{
#ifdef DEBUG
char tmpbuf[40];
#endif
- struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns];
+#if defined USE_HOOKS || defined DEBUG
+ struct sockaddr *nsap = get_nsaddr (statp, ns);
+#endif
- if (nsap == NULL)
- goto next_ns;
same_ns:
#ifdef USE_HOOKS
if (__glibc_unlikely (statp->qhook != NULL)) {
@@ -542,9 +502,9 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
Dprint(statp->options & RES_DEBUG,
(stdout, ";; Querying server (# %d) address = %s\n",
- ns + 1, inet_ntop(nsap->sin6_family,
- (nsap->sin6_family == AF_INET6
- ? &nsap->sin6_addr
+ ns + 1, inet_ntop(nsap->sa_family,
+ (nsap->sa_family == AF_INET6
+ ? &((struct sockaddr_in6 *) nsap)->sin6_addr
: &((struct sockaddr_in *) nsap)->sin_addr),
tmpbuf, sizeof (tmpbuf))));
@@ -660,6 +620,22 @@ libresolv_hidden_def (res_nsend)
/* Private */
+static struct sockaddr *
+get_nsaddr (res_state statp, int n)
+{
+
+ if (!statp->nsaddr_list[n].sin_family && EXT(statp).ext)
+ /* - EXT(statp).ext->nsaddrs[n] holds an address that is larger
+ than struct sockaddr, and
+ - user code did not update statp->nsaddr_list[n]. */
+ return &EXT(statp).ext->nsaddrs[n].s;
+ else
+ /* - user code updated statp->nsaddr_list[n], or
+ - statp->nsaddr_list[n] has the same content as
+ EXT(statp).ext->nsaddrs[n]. */
+ return (struct sockaddr *) (void *) &statp->nsaddr_list[n];
+}
+
static int
send_vc(res_state statp,
const u_char *buf, int buflen, const u_char *buf2, int buflen2,
@@ -674,7 +650,7 @@ send_vc(res_state statp,
// XXX REMOVE
// int anssiz = *anssizp;
HEADER *anhp = (HEADER *) ans;
- struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns];
+ struct sockaddr *nsap = get_nsaddr (statp, ns);
int truncating, connreset, n;
/* On some architectures compiler might emit a warning indicating
'resplen' may be used uninitialized. However if buf2 == NULL
@@ -711,8 +687,8 @@ send_vc(res_state statp,
if (getpeername(statp->_vcsock,
(struct sockaddr *)&peer, &size) < 0 ||
- !sock_eq(&peer, nsap)) {
- __res_iclose(statp, false);
+ !sock_eq(&peer, (struct sockaddr_in6 *) nsap)) {
+ __res_iclose(statp, false);
statp->_flags &= ~RES_F_VC;
}
}
@@ -721,20 +697,19 @@ send_vc(res_state statp,
if (statp->_vcsock >= 0)
__res_iclose(statp, false);
- statp->_vcsock = socket(nsap->sin6_family, SOCK_STREAM, 0);
+ statp->_vcsock = socket(nsap->sa_family, SOCK_STREAM, 0);
if (statp->_vcsock < 0) {
*terrno = errno;
Perror(statp, stderr, "socket(vc)", errno);
return (-1);
}
__set_errno (0);
- if (connect(statp->_vcsock, (struct sockaddr *)nsap,
- nsap->sin6_family == AF_INET
+ if (connect(statp->_vcsock, nsap,
+ nsap->sa_family == AF_INET
? sizeof (struct sockaddr_in)
: sizeof (struct sockaddr_in6)) < 0) {
*terrno = errno;
- Aerror(statp, stderr, "connect/vc", errno,
- (struct sockaddr *) nsap);
+ Aerror(statp, stderr, "connect/vc", errno, nsap);
__res_iclose(statp, false);
return (0);
}
@@ -945,8 +920,7 @@ static int
reopen (res_state statp, int *terrno, int ns)
{
if (EXT(statp).nssocks[ns] == -1) {
- struct sockaddr *nsap
- = (struct sockaddr *) EXT(statp).nsaddrs[ns];
+ struct sockaddr *nsap = get_nsaddr (statp, ns);
socklen_t slen;
/* only try IPv6 if IPv6 NS and if not failed before */
diff --git a/resolv/resolv.h b/resolv/resolv.h
index 53c3bba..dffd1db 100644
--- a/resolv/resolv.h
+++ b/resolv/resolv.h
@@ -100,6 +100,7 @@ typedef res_sendhookact (*res_send_rhook) (const struct sockaddr_in *__ns,
# define RES_MAXRETRY 5 /* only for resolv.conf/RES_OPTIONS */
# define RES_DFLRETRY 2 /* Default #/tries. */
# define RES_MAXTIME 65535 /* Infinity, in milliseconds. */
+struct __res_state_ext;
struct __res_state {
int retrans; /* retransmition time interval */
@@ -133,11 +134,11 @@ struct __res_state {
char pad[52]; /* On an i386 this means 512b total. */
struct {
u_int16_t nscount;
- u_int16_t nsmap[MAXNS];
+ u_int16_t __glibc_reserved1[MAXNS];
int nssocks[MAXNS];
- u_int16_t nscount6;
- u_int16_t nsinit;
- struct sockaddr_in6 *nsaddrs[MAXNS];
+ u_int16_t __glibc_reserved2[2];
+ struct __res_state_ext *ext; /* extension for IPv6 */
+ void *__glibc_reserved3[MAXNS-1];
#ifdef _LIBC
unsigned long long int initstamp
__attribute__((packed));
--
2.3.0
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