[16/25] getent: Switch to struct scratch_buffer in initgroups_keys
Commit Message
The retry loop is slightly different here because getgrouplist
provides size information, so scratch_buffer_set_array_size can be
used to grow the buffer in a more precise fashion.
---
nss/getent.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
@@ -39,6 +39,7 @@
#include <netinet/ether.h>
#include <netinet/in.h>
#include <sys/socket.h>
+#include <scratch_buffer.h>
/* Get libc version number. */
#include <version.h>
@@ -513,30 +514,34 @@ netgroup_keys (int number, char *key[])
static int
initgroups_keys (int number, char *key[])
{
- int ngrps = 100;
- size_t grpslen = ngrps * sizeof (gid_t);
- gid_t *grps = alloca (grpslen);
-
if (number == 0)
{
fprintf (stderr, _("Enumeration not supported on %s\n"), "initgroups");
return 3;
}
+ struct scratch_buffer tmpbuf;
+ scratch_buffer_init (&tmpbuf);
+
for (int i = 0; i < number; ++i)
{
+ ssize_t ngrps = tmpbuf.length / sizeof (gid_t);
int no = ngrps;
int n;
- while ((n = getgrouplist (key[i], -1, grps, &no)) == -1
+ while ((n = getgrouplist (key[i], -1, tmpbuf.data, &no)) == -1
&& no > ngrps)
{
- grps = extend_alloca (grps, grpslen, no * sizeof (gid_t));
- ngrps = no;
+ if (!scratch_buffer_set_array_size (&tmpbuf, no, sizeof (gid_t)))
+ {
+ fprintf (stderr, _("Could not allocate group list: %m\n"));
+ return 3;
+ }
}
if (n == -1)
return 1;
+ const gid_t *grps = tmpbuf.data;
printf ("%-21s", key[i]);
for (int j = 0; j < n; ++j)
if (grps[j] != -1)
@@ -544,6 +549,8 @@ initgroups_keys (int number, char *key[])
putchar_unlocked ('\n');
}
+ scratch_buffer_free (&tmpbuf);
+
return 0;
}