[PATCH] util: open XML files before calling libxml2
Libxml2 has awful error reporting behaviour when reading files. When
we fail to load a file from the test driver we see:
$ virsh -c test:///wibble.xml
I/O warning : failed to load external entity "/wibble.xml"
error: failed to connect to the hypervisor
error: XML error: failed to parse xml document '/wibble.xml'
where the I/O warning line is something printed by libxml2 itself,
which also lacks any useful detail.
Switching to our own file reading code we can massively improve
things:
$ ./build/tools/virsh -c test:///wibble.xml
error: failed to connect to the hypervisor
error: Failed to open file '/wibble.xml': No such file or directory
Using 10 MB as an upper limit on XML file size ought to be sufficient
for any XML files libvirt is reading.
Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com>
---
src/util/virxml.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/src/util/virxml.c b/src/util/virxml.c
index a7b75fd7b3..f6b937b277 100644
--- a/src/util/virxml.c
+++ b/src/util/virxml.c
@@ -1133,6 +1133,7 @@ virXMLParseHelper(int domcode,
xmlNodePtr rootnode;
const char *docname;
int parseFlags = XML_PARSE_NONET | XML_PARSE_NOWARNING;
+ g_autofree char *xmlStrPtr = NULL;
if (filename)
docname = filename;
@@ -1155,10 +1156,11 @@ virXMLParseHelper(int domcode,
}
if (filename) {
- xml = xmlCtxtReadFile(pctxt, filename, NULL, parseFlags);
- } else {
- xml = xmlCtxtReadDoc(pctxt, BAD_CAST xmlStr, url, NULL, parseFlags);
+ if (virFileReadAll(filename, 1024*1024*10, &xmlStrPtr) < 0)
+ return NULL;
+ xmlStr = xmlStrPtr;
}
+ xml = xmlCtxtReadDoc(pctxt, BAD_CAST xmlStr, url, NULL, parseFlags);
if (!xml) {
if (virGetLastErrorCode() == VIR_ERR_OK) {
--
2.45.2