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Diffstat (limited to 'resolv/gethnamaddr.c')
-rw-r--r--resolv/gethnamaddr.c60
1 files changed, 46 insertions, 14 deletions
diff --git a/resolv/gethnamaddr.c b/resolv/gethnamaddr.c
index 18f4764428..161060ebd6 100644
--- a/resolv/gethnamaddr.c
+++ b/resolv/gethnamaddr.c
@@ -65,6 +65,8 @@ static char rcsid[] = "$Id$";
#include <arpa/nameser.h>
#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
#include <netdb.h>
#include <resolv.h>
#include <ctype.h>
@@ -823,7 +825,7 @@ _gethtent()
}
struct hstorage {
- char name[MAXHOSTNAMELEN + 1]; /* canonical name */
+ char *name; /* canonical name */
char ** alp; /* address list pointer */
char * abp; /* address buffer pointer */
char * addr_list[MAXADDRS + 1]; /* address list storage */
@@ -891,20 +893,53 @@ _gethtbyname2(name, af)
* interface changes to make these functions
* reentrant.
*/
- static char * aliases[2];
- static char alias[MAXHOSTNAMELEN + 1];
- static struct hstorage self, target;
+ static char *aliases[2] = {0};
+ static struct hstorage self = {0}, target = {0};
+ static size_t self_name_size = 0; /* Allocated in self.name. */
static struct hostent ht;
int found;
+ if (aliases[0])
+ free (aliases[0]); /* Malloced in a prev call. */
aliases[0] = aliases[1] = 0;
- gethostname(self.name, sizeof(self.name));
+ /* Get current host name in a large enough buffer. */
+ do {
+ errno = 0;
+
+ if (self.name)
+ {
+ self_name_size += self_name_size;
+ self.name =
+ realloc (self.name, self_name_size);
+ } else {
+ self_name_size = 128; /* Initial guess */
+ self.name = malloc (self_name_size);
+ }
+
+ if (! self.name)
+ {
+ errno = ENOMEM;
+ return 0;
+ }
+ } while ((gethostname(self.name, self_name_size) == 0
+ && !memchr (self.name, '\0', self_name_size))
+ || errno == ENAMETOOLONG);
+
+ if (errno)
+ /* gethostname failed, abort. */
+ {
+ free (self.name);
+ self.name = 0;
+ }
+
self.alp = self.addr_list;
self.abp = self.addr_buf;
- strncpy(target.name, name, MAXHOSTNAMELEN);
- target.name[MAXHOSTNAMELEN] = '\0';
+ if (target.name)
+ free (target.name);
+ target.name = strdup (name);
+
target.alp = target.addr_list;
target.abp = target.addr_buf;
@@ -920,13 +955,10 @@ _gethtbyname2(name, af)
if (strcasecmp(*cp, name) == 0) {
found = 1;
if (!aliases[0]) {
- strcpy(target.name,
- p->h_name);
- strncpy(alias, name,
- MAXHOSTNAMELEN);
- alias[MAXHOSTNAMELEN]
- = '\0';
- aliases[0] = alias;
+ aliases[0] =
+ target.name;
+ target.name =
+ strdup (p->h_name);
}
break;
}