[PATCH 5/9] lib: Add libxml2 support

[Sam Mendoza-Jonas]

On Wed, Dec 16, 2015 at 11:54:40AM +1100, Cyril Bur wrote:
> On Tue, 15 Dec 2015 14:15:26 +1100
> Samuel Mendoza-Jonas <sam.mj at au1.ibm.com> wrote:
> 
> > Attribute override functionality on BMC machines will require parsing a
> > Hostboot-provided XML file on startup. This adds generic libxml2 support
> > in order to parse these files.
> > 
> 
> I didn't really go into the nitty gritty of it, I'm sure it works but xml makes
> be die a little bit inside every time.

Yeah I really should have put a warning up top.

> 
> Copyright headers though?

Yep
> 
> Reviewed-by: Cyril Bur <cyril.bur at au1.ibm.com>
> 
> > Signed-off-by: Samuel Mendoza-Jonas <sam.mj at au1.ibm.com>
> > ---
> >  lib/Makefile.am |   7 ++-
> >  lib/xml/xml.c   | 152 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  lib/xml/xml.h   |  19 +++++++
> >  3 files changed, 177 insertions(+), 1 deletion(-)
> >  create mode 100644 lib/xml/xml.c
> >  create mode 100644 lib/xml/xml.h
> > 
> > diff --git a/lib/Makefile.am b/lib/Makefile.am
> > index a3ae943..ea6e5c7 100644
> > --- a/lib/Makefile.am
> > +++ b/lib/Makefile.am
> > @@ -49,20 +49,25 @@ lib_libpbcore_la_SOURCES = \
> >  	lib/url/url.h \
> >  	lib/util/util.c \
> >  	lib/util/util.h \
> > +	lib/xml/xml.h \
> >  	lib/flash/config.h \
> >  	lib/flash/flash.h
> >  
> >  if ENABLE_MTD
> >  lib_libpbcore_la_SOURCES += \
> > +	lib/xml/xml.c \
> >  	lib/flash/flash.c
> >  
> >  lib_libpbcore_la_CPPFLAGS += \
> > +	`xml2-config --cflags` \
> >  	$(AM_CPPFLAGS)
> >  
> >  lib_libpbcore_la_LDFLAGS = \
> > +	`xml2-config --libs` \
> >  	$(AM_LDFLAGS) \
> >  	-l:libflash.so
> >  
> >  lib_libpbcore_la_SOURCES += \
> > -	lib/flash/flash.c
> > +	lib/flash/flash.c \
> > +	lib/xml/xml.c
> >  endif
> > diff --git a/lib/xml/xml.c b/lib/xml/xml.c
> > new file mode 100644
> > index 0000000..057914b
> > --- /dev/null
> > +++ b/lib/xml/xml.c
> > @@ -0,0 +1,152 @@
> > +#include <libxml/parser.h>
> > +#include <libxml/tree.h>
> > +#include <string.h>
> > +
> > +#include <talloc/talloc.h>
> > +#include <log/log.h>
> > +
> > +#include "xml/xml.h"
> > +
> > +xmlDocPtr readXMLFile(const char *path)
> > +{
> > +	xmlParserCtxtPtr ctxt;
> > +	xmlDocPtr doc = NULL;
> > +
> > +	if (!path)
> > +		goto out;
> > +
> > +	LIBXML_TEST_VERSION;
> > +
> > +	ctxt = xmlNewParserCtxt();
> > +	if (!ctxt)
> > +		goto out;
> > +
> > +	/* TODO Incorporate DTD when/if available
> > +	 * doc = xmlCtxtReadFile(ctxt, path, NULL, XML_PARSE_DTDVALID);
> > +	 */
> > +	doc = xmlCtxtReadFile(ctxt, path, NULL, 0);
> > +	if (!doc) {
> > +		pb_log("Failed to parse XML file '%s'\n", path);
> > +		goto out;
> > +	}
> > +
> > +	if (!ctxt->valid) {
> > +		pb_log("XML file '%s' failed DTD check\n", path);
> > +		xmlFreeDoc(doc);
> > +		doc = NULL;
> > +	}
> > +
> > +	xmlFreeParserCtxt(ctxt);
> > +out:
> > +	return doc;
> > +}
> > +
> > +xmlNodePtr findXMLRoot(xmlDocPtr doc, const char *name)
> > +{
> > +	xmlNodePtr node, root = NULL;
> > +
> > +	for (node = xmlDocGetRootElement(doc); node; node = node->next)
> > +		if (node->type == XML_ELEMENT_NODE)
> > +			if (!xmlStrcmp(node->name, (const xmlChar *)name)) {
> > +				root = node;
> > +				break;
> > +			}
> > +	return root;
> > +}
> > +
> > +
> > +/* Return first child node matching name */
> > +xmlNodePtr findChildNode(xmlNodePtr root, xmlElementType type,
> > +			 const char *name)
> > +{
> > +	xmlNodePtr cur;
> > +
> > +	for (cur = root->children; cur; cur = cur->next)
> > +		if (!type || cur->type == type)
> > +			if (!xmlStrcmp(cur->name, (const xmlChar *)name))
> > +			    return cur;
> > +	return NULL;
> > +}
> > +
> > +/*
> > + * We probably won't end up looping through attributes like we do with
> > + * elements since they will be fairly specific, but here's an
> > + * illustrative example
> > + */
> > +void printAttrs(xmlDocPtr doc, xmlNodePtr node, const char *prefix)
> > +{
> > +	xmlAttrPtr attr;
> > +	xmlChar *key = NULL;
> > +
> > +	for (attr = node->properties; attr; attr = attr->next) {
> > +		key = xmlNodeListGetString(doc, attr->xmlChildrenNode, 1);
> > +		pb_log("%s'%s'->'%s'\n", prefix, attr->name, key);
> > +		xmlFree(key);
> > +	}
> > +}
> > +
> > +char *nodeAttribute(void *ctx, xmlNodePtr node, const char *name)
> > +{
> > +	xmlChar *tmp;
> > +	char *attr;
> > +
> > +	tmp = xmlGetProp(node, (xmlChar *) name);
> > +	attr = talloc_strdup(ctx, (char *) tmp);
> > +
> > +	xmlFree(tmp);
> > +	return attr;
> > +}
> > +
> > +
> > +/* Allocate content under context, return NULL for whitespace-only results */
> > +char *nodeContent(void *ctx, xmlDocPtr doc, xmlNodePtr node)
> > +{
> > +	char *content;
> > +	xmlChar *tmp = xmlNodeListGetString(doc, node->xmlChildrenNode, 1);
> > +	/* xmlNodeGetContent aggregates empty fields */
> > +
> > +	content = talloc_strdup(ctx, (char *)tmp);
> > +	xmlFree(tmp);
> > +
> > +	return content;
> > +}
> > +
> > +bool hasChildren(xmlNodePtr node, xmlElementType type)
> > +{
> > +	xmlNodePtr cur;
> > +	int n = 0;
> > +
> > +	for (cur = node->children; cur; cur = cur->next)
> > +		if (!type || cur->type == type)
> > +			n++;
> > +
> > +	return n;
> > +}
> > +
> > +/* Return child nodes, optionally filtering by type */
> > +int nodeChildren(void *ctx, xmlNodePtr **nodes, xmlNodePtr node,
> > +		 xmlElementType type)
> > +{
> > +	xmlNodePtr cur, *children = NULL;
> > +	int n = 0;
> > +
> > +	for (cur = node->children; cur; cur = cur->next) {
> > +		if (!type || cur->type == type) {
> > +			children = talloc_realloc(ctx, children,
> > +						xmlNodePtr, n + 1);
> > +			children[n++] = cur;
> > +		}
> > +	}
> > +
> > +	*nodes = children;
> > +	return n;
> > +}
> > +
> > +/*
> > + * This should only be called once we are completely finished with the library.
> > + */
> > +void finaliseXML(xmlDocPtr doc)
> > +{
> > +	xmlFreeDoc(doc);
> > +	xmlCleanupParser();
> > +}
> > diff --git a/lib/xml/xml.h b/lib/xml/xml.h
> > new file mode 100644
> > index 0000000..91cc8d3
> > --- /dev/null
> > +++ b/lib/xml/xml.h
> > @@ -0,0 +1,19 @@
> > +#ifndef _XML_H
> > +#define _XML_H
> > +
> > +#include <libxml/tree.h>
> > +
> > +xmlDocPtr readXMLFile(const char *path);
> > +xmlNodePtr findXMLRoot(xmlDocPtr doc, const char *root_name);
> > +xmlNodePtr findChildNode(xmlNodePtr root, xmlElementType type,
> > +			 const char *name);
> > +int nodeChildren(void *ctx, xmlNodePtr **nodes, xmlNodePtr node,
> > +		 xmlElementType type);
> > +bool hasChildren(xmlNodePtr node, xmlElementType type);
> > +
> > +char *nodeContent(void *ctx, xmlDocPtr doc, xmlNodePtr node);
> > +char *nodeAttribute(void *ctx, xmlNodePtr node, const char *name);
> > +void printAttrs(xmlDocPtr doc, xmlNodePtr node, const char *prefix);
> > +void finaliseXML(xmlDocPtr doc);
> > +
> > +#endif /* _XML_H */
>