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authorFlorian Weimer <fweimer@redhat.com>2017-06-19 14:05:49 +0200
committerFlorian Weimer <fweimer@redhat.com>2017-06-19 14:24:24 +0200
commitea4924ce5bccfccc4e8a492faa96933131abd9ef (patch)
treeaede7806f62e30d2a4a01121d436e501c2b93fdd
parent4c4480eecb2e00764dd3bf79d68ea4e1d747d78c (diff)
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resolv: Report allocation errors in __res_vinit
-rw-r--r--ChangeLog12
-rw-r--r--resolv/nss_dns/dns-host.c18
-rw-r--r--resolv/nss_dns/dns-network.c12
-rw-r--r--resolv/res_init.c93
4 files changed, 101 insertions, 34 deletions
diff --git a/ChangeLog b/ChangeLog
index 6e57e98..387f038 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,17 @@
2017-06-19 Florian Weimer <fweimer@redhat.com>
+ * resolv/res_init.c (res_vinit_1): New function.
+ (__res_vinit): Call it. Handle file open and memory allocation
+ failures.
+ * resolv/nss_dns/dns-host.c (_nss_dns_gethostbyname3_r): Propagate
+ erno from __res_maybe_init failure.
+ (_nss_dns_gethostbyname4_r): Likewise.
+ (_nss_dns_gethostbyaddr2_r): Likewise.
+ * resolv/nss_dns/dns-network.c (_nss_dns_getnetbyname_r): Likewise.
+ (_nss_dns_getnetbyaddr_r): Likewise.
+
+2017-06-19 Florian Weimer <fweimer@redhat.com>
+
* resolv/res_init.c: Reformat to GNU style.
2017-06-19 Florian Weimer <fweimer@redhat.com>
diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c
index f121aa3..206924d 100644
--- a/resolv/nss_dns/dns-host.c
+++ b/resolv/nss_dns/dns-host.c
@@ -164,7 +164,11 @@ _nss_dns_gethostbyname3_r (const char *name, int af, struct hostent *result,
enum nss_status status;
if (__res_maybe_init (&_res, 0) == -1)
- return NSS_STATUS_UNAVAIL;
+ {
+ *errnop = errno;
+ *h_errnop = NETDB_INTERNAL;
+ return NSS_STATUS_UNAVAIL;
+ }
switch (af) {
case AF_INET:
@@ -289,7 +293,11 @@ _nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
int *herrnop, int32_t *ttlp)
{
if (__res_maybe_init (&_res, 0) == -1)
- return NSS_STATUS_UNAVAIL;
+ {
+ *errnop = errno;
+ *herrnop = NETDB_INTERNAL;
+ return NSS_STATUS_UNAVAIL;
+ }
/*
* if there aren't any dots, it could be a user-level alias.
@@ -416,7 +424,11 @@ _nss_dns_gethostbyaddr2_r (const void *addr, socklen_t len, int af,
host_data = (struct host_data *) buffer;
if (__res_maybe_init (&_res, 0) == -1)
- return NSS_STATUS_UNAVAIL;
+ {
+ *errnop = errno;
+ *h_errnop = NETDB_INTERNAL;
+ return NSS_STATUS_UNAVAIL;
+ }
if (af == AF_INET6 && len == IN6ADDRSZ
&& (memcmp (uaddr, mapped, sizeof mapped) == 0
diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c
index 2be72d3..dc1599b 100644
--- a/resolv/nss_dns/dns-network.c
+++ b/resolv/nss_dns/dns-network.c
@@ -116,7 +116,11 @@ _nss_dns_getnetbyname_r (const char *name, struct netent *result,
enum nss_status status;
if (__res_maybe_init (&_res, 0) == -1)
- return NSS_STATUS_UNAVAIL;
+ {
+ *errnop = errno;
+ *herrnop = NETDB_INTERNAL;
+ return NSS_STATUS_UNAVAIL;
+ }
net_buffer.buf = orig_net_buffer = (querybuf *) alloca (1024);
@@ -166,7 +170,11 @@ _nss_dns_getnetbyaddr_r (uint32_t net, int type, struct netent *result,
return NSS_STATUS_UNAVAIL;
if (__res_maybe_init (&_res, 0) == -1)
- return NSS_STATUS_UNAVAIL;
+ {
+ *errnop = errno;
+ *herrnop = NETDB_INTERNAL;
+ return NSS_STATUS_UNAVAIL;
+ }
net2 = (u_int32_t) net;
for (cnt = 4; net2 != 0; net2 >>= 8)
diff --git a/resolv/res_init.c b/resolv/res_init.c
index 49fc945..e604a02 100644
--- a/resolv/res_init.c
+++ b/resolv/res_init.c
@@ -100,6 +100,7 @@
#include <sys/time.h>
#include <sys/types.h>
#include <inet/net-internal.h>
+#include <errno.h>
static void res_setoptions (res_state, const char *, const char *);
static uint32_t net_mask (struct in_addr);
@@ -121,14 +122,11 @@ is_sort_mask (char ch)
return ch == '/' || ch == '&';
}
-/* Set up default settings. If the /etc/resolv.conf configuration
- file exist, the values there will have precedence. Otherwise, the
- server address is set to INADDR_LOOPBACK and the default domain
- name comes from gethostname. The RES_OPTIONS and LOCALDOMAIN
- environment variables can be used to override some settings.
- Return 0 if completes successfully, -1 on error. */
-int
-__res_vinit (res_state statp, int preinit)
+/* Internal helper function for __res_vinit, to aid with resource
+ deallocation and error handling. Return true on success, false on
+ failure. */
+static bool
+res_vinit_1 (res_state statp, bool preinit, FILE *fp)
{
char *cp, **pp;
char buf[BUFSIZ];
@@ -203,7 +201,6 @@ __res_vinit (res_state statp, int preinit)
&& (line[sizeof (name) - 1] == ' ' \
|| line[sizeof (name) - 1] == '\t'))
- FILE *fp = fopen (_PATH_RESCONF, "rce");
if (fp != NULL)
{
/* No threads use this stream. */
@@ -302,26 +299,26 @@ __res_vinit (res_state statp, int preinit)
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;
-
- sa6->sin6_scope_id = 0;
- if (__glibc_likely (el != NULL))
- /* Ignore errors, for backwards
- compatibility. */
- __inet6_scopeid_pton
- (&a6, el + 1, &sa6->sin6_scope_id);
-
- statp->nsaddr_list[nserv].sin_family = 0;
- statp->_u._ext.nsaddrs[nserv] = sa6;
- statp->_u._ext.nssocks[nserv] = -1;
- have_serv6 = true;
- nserv++;
- }
+ if (sa6 == NULL)
+ return -1;
+
+ sa6->sin6_family = AF_INET6;
+ sa6->sin6_port = htons (NAMESERVER_PORT);
+ sa6->sin6_flowinfo = 0;
+ sa6->sin6_addr = a6;
+
+ sa6->sin6_scope_id = 0;
+ if (__glibc_likely (el != NULL))
+ /* Ignore errors, for backwards
+ compatibility. */
+ __inet6_scopeid_pton
+ (&a6, el + 1, &sa6->sin6_scope_id);
+
+ statp->nsaddr_list[nserv].sin_family = 0;
+ statp->_u._ext.nsaddrs[nserv] = sa6;
+ statp->_u._ext.nssocks[nserv] = -1;
+ have_serv6 = true;
+ nserv++;
}
}
continue;
@@ -410,6 +407,44 @@ __res_vinit (res_state statp, int preinit)
return 0;
}
+/* Set up default settings. If the /etc/resolv.conf configuration
+ file exist, the values there will have precedence. Otherwise, the
+ server address is set to INADDR_LOOPBACK and the default domain
+ name comes from gethostname. The RES_OPTIONS and LOCALDOMAIN
+ environment variables can be used to override some settings.
+ Return 0 if completes successfully, -1 on error. */
+int
+__res_vinit (res_state statp, int preinit)
+{
+ FILE *fp = fopen (_PATH_RESCONF, "rce");
+ if (fp == NULL)
+ switch (errno)
+ {
+ case EACCES:
+ case EISDIR:
+ case ELOOP:
+ case ENOENT:
+ case ENOTDIR:
+ case EPERM:
+ /* Ignore these errors. They are persistent errors caused
+ by file system contents. */
+ break;
+ default:
+ /* Other errors refer to resource allocation problems and
+ need to be handled by the application. */
+ return -1;
+ }
+ if (!res_vinit_1 (statp, preinit, fp))
+ {
+ /* Deallocate the name server addresses which have been
+ allocated. */
+ for (int n = 0; n < MAXNS; n++)
+ free (statp->_u._ext.nsaddrs[n]);
+ return -1;
+ }
+ return 0;
+}
+
static void
res_setoptions (res_state statp, const char *options, const char *source)
{