resolv: Report allocation errors in __res_vinit

This commit is contained in:
Florian Weimer 2017-06-19 14:05:49 +02:00
parent 4c4480eecb
commit ea4924ce5b
4 changed files with 99 additions and 32 deletions

View File

@ -1,3 +1,15 @@
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.

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@ -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)
{
*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)
{
*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)
{
*errnop = errno;
*h_errnop = NETDB_INTERNAL;
return NSS_STATUS_UNAVAIL;
}
if (af == AF_INET6 && len == IN6ADDRSZ
&& (memcmp (uaddr, mapped, sizeof mapped) == 0

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@ -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)
{
*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)
{
*errnop = errno;
*herrnop = NETDB_INTERNAL;
return NSS_STATUS_UNAVAIL;
}
net2 = (u_int32_t) net;
for (cnt = 4; net2 != 0; net2 >>= 8)

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@ -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. */
@ -302,8 +299,9 @@ __res_vinit (res_state statp, int preinit)
struct sockaddr_in6 *sa6;
sa6 = malloc (sizeof (*sa6));
if (sa6 != NULL)
{
if (sa6 == NULL)
return -1;
sa6->sin6_family = AF_INET6;
sa6->sin6_port = htons (NAMESERVER_PORT);
sa6->sin6_flowinfo = 0;
@ -323,7 +321,6 @@ __res_vinit (res_state statp, int preinit)
nserv++;
}
}
}
continue;
}
if (MATCH (buf, "sortlist"))
@ -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)
{