Hi,
determines the maximum needed buffersize for getgrnam_r using sysconf
instead of hardcoding it to 1024 and increases the buffer on ERANGE.
The latter is needed since sysconf is allowed to return -1. Furthermore
some glibc versions seem to return a too small buffer on amd64
(http://bugs.debian.org/520744). O.k. to apply?
Cheers,
-- Guido
>From b0f965f3fbc39040569e07097e9461b7b3224022 Mon Sep 17 00:00:00 2001
From: =?utf-8?q?Guido=20G=C3=BCnther?= <[email protected]>
Date: Tue, 14 Apr 2009 18:08:16 +0200
Subject: [PATCH] increase buffer on ERANGE
---
qemud/qemud.c | 27 +++++++++++++++++++++++++--
1 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/qemud/qemud.c b/qemud/qemud.c
index 4f04355..461c612 100644
--- a/qemud/qemud.c
+++ b/qemud/qemud.c
@@ -2529,6 +2529,7 @@ remoteReadConfigFile (struct qemud_server *server, const char *filename)
char *unix_sock_ro_perms = NULL;
char *unix_sock_rw_perms = NULL;
char *unix_sock_group = NULL;
+ char *buf = NULL;
#if HAVE_POLKIT
/* Change the default back to no auth for non-root */
@@ -2574,13 +2575,34 @@ remoteReadConfigFile (struct qemud_server *server, const char *filename)
if (getuid() != 0) {
VIR_WARN0(_("Cannot set group when not running as root"));
} else {
- char buf[1024];
+ int ret;
struct group grpdata, *grp;
- if (getgrnam_r(unix_sock_group, &grpdata, buf, sizeof(buf), &grp) != 0 || !grp) {
+ size_t maxbuf = sysconf(_SC_GETGR_R_SIZE_MAX);
+
+ if (maxbuf == -1)
+ maxbuf = 1024;
+
+ if (VIR_ALLOC_N(buf, maxbuf) < 0) {
+ VIR_ERROR("%s", _("Failed to allocate memory for buffer"));
+ goto free_and_fail;
+ }
+
+ while ((ret = getgrnam_r(unix_sock_group, &grpdata,
+ buf, maxbuf,
+ &grp)) == ERANGE) {
+ maxbuf *= 2;
+ if (VIR_REALLOC_N(buf, maxbuf) < 0) {
+ VIR_ERROR("%s", _("Failed to reallocate memory for buffer"));
+ goto free_and_fail;
+ }
+ }
+
+ if (ret != 0 || !grp) {
VIR_ERROR(_("Failed to lookup group '%s'"), unix_sock_group);
goto free_and_fail;
}
unix_sock_gid = grp->gr_gid;
+ VIR_FREE (buf);
}
free (unix_sock_group);
unix_sock_group = NULL;
@@ -2643,6 +2665,7 @@ remoteReadConfigFile (struct qemud_server *server, const char *filename)
free (unix_sock_ro_perms);
free (unix_sock_rw_perms);
free (unix_sock_group);
+ VIR_FREE (buf);
/* Don't bother trying to free listen_addr, tcp_port, tls_port, key_file,
cert_file, ca_file, or crl_file, since they are initialized to
--
1.6.2.1
--
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