Handle ngroups>_SC_NGROUPS_MAX.

Based on github pull request #99 from Darren Maffat at Oracle: Solaris'
getgrouplist considers _SC_NGROUPS_MAX more of a guideline and can return
a larger number of groups.  In this case, retry getgrouplist with a
larger array and defer allocating groups_byname.  ok djm@

1 files changed, 8 insertions, 3 deletions

diff --git a/groupaccess.c b/groupaccess.c
index 2518c8487..9e4d25521 100644
--- a/groupaccess.c
+++ b/groupaccess.c
@@ -50,7 +50,7 @@ int
 ga_init(const char *user, gid_t base)
 {
         gid_t *groups_bygid;
-        int i, j;
+        int i, j, retry = 0;
         struct group *gr;
 
         if (ngroups > 0)
@@ -62,10 +62,14 @@ ga_init(const char *user, gid_t base)
 #endif
 
         groups_bygid = xcalloc(ngroups, sizeof(*groups_bygid));
+        while (getgrouplist(user, base, groups_bygid, &ngroups) == -1) {
+                if (retry++ > 0)
+                        fatal("getgrouplist: groups list too small");
+                groups_bygid = xreallocarray(groups_bygid, ngroups,
+                    sizeof(*groups_bygid));
+        }
         groups_byname = xcalloc(ngroups, sizeof(*groups_byname));
 
-        if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
-                logit("getgrouplist: groups list too small");
         for (i = 0, j = 0; i < ngroups; i++)
                 if ((gr = getgrgid(groups_bygid[i])) != NULL)
                         groups_byname[j++] = xstrdup(gr->gr_name);
@@ -124,5 +128,6 @@ ga_free(void)
                         free(groups_byname[i]);
                 ngroups = 0;
                 free(groups_byname);
+                groups_byname = NULL;
         }
 }