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authorAndreas Schwab <schwab@suse.de>2015-02-19 15:52:08 +0100
committerAndreas Schwab <schwab@suse.de>2015-05-21 15:16:37 +0200
commit2212c1420c92a33b0e0bd9a34938c9814a56c0f7 (patch)
tree47aebf7bf280857cf2c0279cdaf6493b453c3dfd /resolv
parentf58573781c3541d6a666036a6a815ea052242065 (diff)
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Simplify handling of nameserver configuration in resolver
Remove use of ext.nsmap member of struct __res_state and always use an identity mapping betwen the nsaddr_list array and the ext.nsaddrs array. The fact that a nameserver has an IPv6 address is signalled by setting nsaddr_list[].sin_family to zero.
Diffstat (limited to 'resolv')
-rw-r--r--resolv/res_init.c47
-rw-r--r--resolv/res_send.c164
2 files changed, 84 insertions, 127 deletions
diff --git a/resolv/res_init.c b/resolv/res_init.c
index 553ba12..66561ff 100644
--- a/resolv/res_init.c
+++ b/resolv/res_init.c
@@ -153,10 +153,8 @@ __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 +182,9 @@ __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;
- }
-#endif
+ for (n = 0; n < MAXNS; n++)
+ statp->_u._ext.nsaddrs[n] = NULL;
/* Allow user to override the local domain definition */
if ((cp = getenv("LOCALDOMAIN")) != NULL) {
@@ -296,11 +288,7 @@ __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 +296,12 @@ __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;
@@ -356,10 +343,11 @@ __res_vinit(res_state statp, int preinit) {
}
}
- statp->_u._ext.nsaddrs[nservall] = sa6;
- statp->_u._ext.nssocks[nservall] = -1;
- statp->_u._ext.nsmap[nservall] = MAXNS + 1;
- nservall++;
+ statp->nsaddr_list[nserv].sin_family = 0;
+ statp->_u._ext.nsaddrs[nserv] = sa6;
+ statp->_u._ext.nssocks[nserv] = -1;
+ have_serv6 = 1;
+ nserv++;
}
}
#endif
@@ -414,10 +402,9 @@ __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;
}
@@ -606,11 +593,7 @@ __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]);
@@ -621,8 +604,6 @@ __res_iclose(res_state statp, bool free_addr) {
statp->_u._ext.nsaddrs[ns] = NULL;
}
}
- if (free_addr)
- statp->_u._ext.nsinit = 0;
}
libc_hidden_def (__res_iclose)
diff --git a/resolv/res_send.c b/resolv/res_send.c
index c35fb66..5e53cc2 100644
--- a/resolv/res_send.c
+++ b/resolv/res_send.c
@@ -184,6 +184,7 @@ evNowTime(struct timespec *res) {
/* 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 +222,21 @@ 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 +386,48 @@ __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],
+ &statp->nsaddr_list[ns],
EXT(statp).nsaddrs[ns]))
{
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;
- }
- }
- 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] =
+ 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)
+ continue;
+ if (EXT(statp).nsaddrs[ns] == NULL)
+ EXT(statp).nsaddrs[ns] =
malloc(sizeof (struct sockaddr_in6));
- if (EXT(statp).nsaddrs[n] != NULL) {
- memset (mempcpy(EXT(statp).nsaddrs[n],
+ if (EXT(statp).nsaddrs[ns] != NULL)
+ memset (mempcpy(EXT(statp).nsaddrs[ns],
&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 +436,37 @@ __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;
+ struct sockaddr_in ina;
+ struct sockaddr_in6 *inp;
+ int lastns = statp->nscount - 1;
+ int fd;
+
+ inp = EXT(statp).nsaddrs[0];
+ ina = statp->nsaddr_list[0];
+ fd = EXT(statp).nssocks[0];
+ for (ns = 0; ns < lastns; ns++) {
+ EXT(statp).nsaddrs[ns] = EXT(statp).nsaddrs[ns + 1];
+ statp->nsaddr_list[ns] = statp->nsaddr_list[ns + 1];
+ EXT(statp).nssocks[ns] = EXT(statp).nssocks[ns + 1];
}
+ EXT(statp).nsaddrs[lastns] = inp;
+ 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 +505,9 @@ __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 +623,21 @@ libresolv_hidden_def (res_nsend)
/* Private */
+static struct sockaddr *
+get_nsaddr (res_state statp, int n)
+{
+
+ if (statp->nsaddr_list[n].sin_family == 0 && EXT(statp).nsaddrs[n] != NULL)
+ /* EXT(statp).nsaddrs[n] holds an address that is larger than
+ struct sockaddr, and user code did not update
+ statp->nsaddr_list[n]. */
+ return (struct sockaddr *) EXT(statp).nsaddrs[n];
+ else
+ /* User code updated statp->nsaddr_list[n], or statp->nsaddr_list[n]
+ has the same content as EXT(statp).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 +652,7 @@ 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 +689,8 @@ 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 +699,19 @@ 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 +922,7 @@ 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 */