Re: [libvirt PATCH 06/32] util: use getgrouplist() directly instead of mgetgroups

The mgetgroups function is a GNULIB custom wrapper around getgrouplist(). This implements a simplified version of that code directly. Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- src/internal.h | 4 ++++ src/util/virutil.c | 34 ++++++++++++++++++++++++++++------ 2 files changed, 32 insertions(+), 6 deletions(-) diff --git a/src/util/virutil.c b/src/util/virutil.c index 87ca16c088..4bc0aef35f 100644 --- a/src/util/virutil.c +++ b/src/util/virutil.c @@ -1000,11 +1004,27 @@ virGetGroupList(uid_t uid, gid_t gid, gid_t **list) /* invalid users have no supplementary groups */ if (uid != (uid_t)-1 && virGetUserEnt(uid, &user, &primary, NULL, NULL, true) >= 0) { - if ((ret = mgetgroups(user, primary, list)) < 0) { - virReportSystemError(errno, - _("cannot get group list for '%s'"), user); - ret = -1; - goto cleanup; + int nallocgrps = 10; + gid_t *grps = g_new(gid_t, nallocgrps);

+ while (1) { + int nprevallocgrps = nallocgrps; + int rv; + + rv = getgrouplist(user, primary, grps, &nallocgrps); + + /* Some systems (like Darwin) have a bug where they + never increase max_n_groups. */ + if (rv < 0 && nprevallocgrps == nallocgrps) + nallocgrps *= 2; + + /* either shrinks to actual size, or enlarges tonew size */

+ grps = g_renew(gid_t, grps, nallocgrps); + + if (rv >= 0) { + ret = rv; + break;