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@xxxxxxxxxx>
---
src/util/virxml.c | 8 +++++---
tests/qemuxmlconfdata/nonexistent-file.x86_64-latest.err | 2 +-
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/src/util/virxml.c b/src/util/virxml.c
index 797aa6f6ca..deed258bb0 100644
--- a/src/util/virxml.c
+++ b/src/util/virxml.c
@@ -1142,6 +1142,7 @@ 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;
@@ -1165,10 +1166,11 @@ 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) {
diff --git a/tests/qemuxmlconfdata/nonexistent-file.x86_64-latest.err b/tests/qemuxmlconfdata/nonexistent-file.x86_64-latest.err
index 0ddf1ea510..2aedf3eded 100644
--- a/tests/qemuxmlconfdata/nonexistent-file.x86_64-latest.err
+++ b/tests/qemuxmlconfdata/nonexistent-file.x86_64-latest.err
@@ -1 +1 @@
-XML error: failed to parse xml document 'ABS_SRCDIR/qemuxmlconfdata/nonexistent-file.xml'
+Failed to open file 'ABS_SRCDIR/qemuxmlconfdata/nonexistent-file.xml': No such file or directory
--
2.46.0
