update_client: refactor the parsing and serializing of XML.
This is a mechanical change.
It introduces ProtocolParser and ProtocolSerializer abstract classes
to allow different protocols in the future. Only the XML implementation
of these classes is provided in this changelist.
Bug: 848505
Change-Id: I4bda0f92f5b676f0f0eaca7dc841c8dca9c282ad
Reviewed-on: https://chromium-review.googlesource.com/c/1278476
Commit-Queue: Sorin Jianu <[email protected]>
Reviewed-by: Joshua Pawlicki <[email protected]>
Cr-Commit-Position: refs/heads/master@{#599366}diff --git a/components/update_client/protocol_parser.cc b/components/update_client/protocol_parser.cc
index efd88dd..cea8744 100644
--- a/components/update_client/protocol_parser.cc
+++ b/components/update_client/protocol_parser.cc
@@ -3,19 +3,8 @@
// found in the LICENSE file.
#include "components/update_client/protocol_parser.h"
-
-#include <stddef.h>
-
-#include <algorithm>
-#include <memory>
-
-#include "base/stl_util.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
-#include "base/version.h"
-#include "libxml/tree.h"
-#include "third_party/libxml/chromium/libxml_utils.h"
+#include "components/update_client/protocol_parser_xml.h"
namespace update_client {
@@ -55,372 +44,17 @@
va_end(args);
}
-// Checks whether a given node's name matches |expected_name|.
-static bool TagNameEquals(const xmlNode* node, const char* expected_name) {
- return 0 == strcmp(expected_name, reinterpret_cast<const char*>(node->name));
-}
-
-// Returns child nodes of |root| with name |name|.
-static std::vector<xmlNode*> GetChildren(xmlNode* root, const char* name) {
- std::vector<xmlNode*> result;
- for (xmlNode* child = root->children; child != nullptr; child = child->next) {
- if (!TagNameEquals(child, name)) {
- continue;
- }
- result.push_back(child);
- }
- return result;
-}
-
-// Returns the value of a named attribute, or the empty string.
-static std::string GetAttribute(xmlNode* node, const char* attribute_name) {
- const xmlChar* name = reinterpret_cast<const xmlChar*>(attribute_name);
- for (xmlAttr* attr = node->properties; attr != nullptr; attr = attr->next) {
- if (!xmlStrcmp(attr->name, name) && attr->children &&
- attr->children->content) {
- return std::string(
- reinterpret_cast<const char*>(attr->children->content));
- }
- }
- return std::string();
-}
-
-// Returns the value of a named attribute, or nullptr .
-static std::unique_ptr<std::string> GetAttributePtr(
- xmlNode* node,
- const char* attribute_name) {
- const xmlChar* name = reinterpret_cast<const xmlChar*>(attribute_name);
- for (xmlAttr* attr = node->properties; attr != nullptr; attr = attr->next) {
- if (!xmlStrcmp(attr->name, name) && attr->children &&
- attr->children->content) {
- return std::make_unique<std::string>(
- reinterpret_cast<const char*>(attr->children->content));
- }
- }
- return nullptr;
-}
-
-// This is used for the xml parser to report errors. This assumes the context
-// is a pointer to a std::string where the error message should be appended.
-static void XmlErrorFunc(void* context, const char* message, ...) {
- va_list args;
- va_start(args, message);
- std::string* error = static_cast<std::string*>(context);
- base::StringAppendV(error, message, args);
- va_end(args);
-}
-
-// Utility class for cleaning up the xml document when leaving a scope.
-class ScopedXmlDocument {
- public:
- explicit ScopedXmlDocument(xmlDocPtr document) : document_(document) {}
- ~ScopedXmlDocument() {
- if (document_)
- xmlFreeDoc(document_);
- }
-
- xmlDocPtr get() { return document_; }
-
- private:
- xmlDocPtr document_;
-};
-
-// Parses the <package> tag.
-bool ParsePackageTag(xmlNode* package,
- ProtocolParser::Result* result,
- std::string* error) {
- ProtocolParser::Result::Manifest::Package p;
- p.name = GetAttribute(package, "name");
- if (p.name.empty()) {
- *error = "Missing name for package.";
- return false;
- }
-
- p.namediff = GetAttribute(package, "namediff");
-
- // package_fingerprint is optional. It identifies the package, preferably
- // with a modified sha256 hash of the package in hex format.
- p.fingerprint = GetAttribute(package, "fp");
-
- p.hash_sha256 = GetAttribute(package, "hash_sha256");
- int size = 0;
- if (base::StringToInt(GetAttribute(package, "size"), &size)) {
- p.size = size;
- }
-
- p.hashdiff_sha256 = GetAttribute(package, "hashdiff_sha256");
- int sizediff = 0;
- if (base::StringToInt(GetAttribute(package, "sizediff"), &sizediff)) {
- p.sizediff = sizediff;
- }
-
- result->manifest.packages.push_back(p);
-
- return true;
-}
-
-// Parses the <manifest> tag.
-bool ParseManifestTag(xmlNode* manifest,
- ProtocolParser::Result* result,
- std::string* error) {
- // Get the version.
- result->manifest.version = GetAttribute(manifest, "version");
- if (result->manifest.version.empty()) {
- *error = "Missing version for manifest.";
- return false;
- }
- base::Version version(result->manifest.version);
- if (!version.IsValid()) {
- *error = "Invalid version: '";
- *error += result->manifest.version;
- *error += "'.";
- return false;
- }
-
- // Get the minimum browser version (not required).
- result->manifest.browser_min_version =
- GetAttribute(manifest, "prodversionmin");
- if (result->manifest.browser_min_version.length()) {
- base::Version browser_min_version(result->manifest.browser_min_version);
- if (!browser_min_version.IsValid()) {
- *error = "Invalid prodversionmin: '";
- *error += result->manifest.browser_min_version;
- *error += "'.";
- return false;
- }
- }
-
- // Get the <packages> node.
- std::vector<xmlNode*> packages = GetChildren(manifest, "packages");
- if (packages.empty()) {
- *error = "Missing packages tag on manifest.";
- return false;
- }
-
- // Parse each of the <package> tags.
- std::vector<xmlNode*> package = GetChildren(packages[0], "package");
- for (size_t i = 0; i != package.size(); ++i) {
- if (!ParsePackageTag(package[i], result, error))
- return false;
- }
-
- return true;
-}
-
-// Parses the <urls> tag and its children in the <updatecheck>.
-bool ParseUrlsTag(xmlNode* urls,
- ProtocolParser::Result* result,
- std::string* error) {
- // Get the url nodes.
- std::vector<xmlNode*> url = GetChildren(urls, "url");
- if (url.empty()) {
- *error = "Missing url tags on urls.";
- return false;
- }
-
- // Get the list of urls for full and optionally, for diff updates.
- // There can only be either a codebase or a codebasediff attribute in a tag.
- for (size_t i = 0; i != url.size(); ++i) {
- // Find the url to the crx file.
- const GURL crx_url(GetAttribute(url[i], "codebase"));
- if (crx_url.is_valid()) {
- result->crx_urls.push_back(crx_url);
- continue;
- }
- const GURL crx_diffurl(GetAttribute(url[i], "codebasediff"));
- if (crx_diffurl.is_valid()) {
- result->crx_diffurls.push_back(crx_diffurl);
- continue;
- }
- }
-
- // Expect at least one url for full update.
- if (result->crx_urls.empty()) {
- *error = "Missing valid url for full update.";
- return false;
- }
-
- return true;
-}
-
-// Parses the <actions> tag. It picks up the "run" attribute of the first
-// "action" element in "actions".
-void ParseActionsTag(xmlNode* updatecheck, ProtocolParser::Result* result) {
- std::vector<xmlNode*> actions = GetChildren(updatecheck, "actions");
- if (actions.empty())
- return;
-
- std::vector<xmlNode*> action = GetChildren(actions.front(), "action");
- if (action.empty())
- return;
-
- result->action_run = GetAttribute(action.front(), "run");
-}
-
-// Parses the <updatecheck> tag.
-bool ParseUpdateCheckTag(xmlNode* updatecheck,
- ProtocolParser::Result* result,
- std::string* error) {
- // Read the |status| attribute.
- result->status = GetAttribute(updatecheck, "status");
- if (result->status.empty()) {
- *error = "Missing status on updatecheck node";
- return false;
- }
-
- if (result->status == "noupdate") {
- ParseActionsTag(updatecheck, result);
- return true;
- }
-
- if (result->status == "ok") {
- std::vector<xmlNode*> urls = GetChildren(updatecheck, "urls");
- if (urls.empty()) {
- *error = "Missing urls on updatecheck.";
- return false;
- }
-
- if (!ParseUrlsTag(urls[0], result, error)) {
- return false;
- }
-
- std::vector<xmlNode*> manifests = GetChildren(updatecheck, "manifest");
- if (manifests.empty()) {
- *error = "Missing manifest on updatecheck.";
- return false;
- }
-
- ParseActionsTag(updatecheck, result);
- return ParseManifestTag(manifests[0], result, error);
- }
-
- // Return the |updatecheck| element status as a parsing error.
- *error = result->status;
- return false;
-}
-
-// Parses a single <app> tag.
-bool ParseAppTag(xmlNode* app,
- ProtocolParser::Result* result,
- std::string* error) {
- // Read cohort information.
- auto cohort = GetAttributePtr(app, "cohort");
- static const char* attrs[] = {ProtocolParser::Result::kCohort,
- ProtocolParser::Result::kCohortHint,
- ProtocolParser::Result::kCohortName};
- for (auto* attr : attrs) {
- auto value = GetAttributePtr(app, attr);
- if (value)
- result->cohort_attrs.insert({attr, *value});
- }
-
- // Read the crx id.
- result->extension_id = GetAttribute(app, "appid");
- if (result->extension_id.empty()) {
- *error = "Missing appid on app node";
- return false;
- }
-
- // Read the |status| attribute for the app.
- // If the status is one of the defined app status error literals, then return
- // it in the result as if it were an updatecheck status, then stop parsing,
- // and return success.
- result->status = GetAttribute(app, "status");
- if (result->status == "restricted" ||
- result->status == "error-unknownApplication" ||
- result->status == "error-invalidAppId")
- return true;
-
- // If the status was not handled above and the status is not "ok", then
- // this must be a status literal that that the parser does not know about.
- if (!result->status.empty() && result->status != "ok") {
- *error = "Unknown app status";
- return false;
- }
-
- // Get the <updatecheck> tag if the status is missing or the status is "ok".
- DCHECK(result->status.empty() || result->status == "ok");
- std::vector<xmlNode*> updates = GetChildren(app, "updatecheck");
- if (updates.empty()) {
- *error = "Missing updatecheck on app.";
- return false;
- }
-
- return ParseUpdateCheckTag(updates[0], result, error);
-}
-
-bool ProtocolParser::Parse(const std::string& response_xml) {
+bool ProtocolParser::Parse(const std::string& response) {
results_.daystart_elapsed_seconds = kNoDaystart;
results_.daystart_elapsed_days = kNoDaystart;
results_.list.clear();
errors_.clear();
- if (response_xml.empty()) {
- ParseError("Empty xml");
- return false;
- }
+ return DoParse(response, &results_);
+}
- std::string xml_errors;
- ScopedXmlErrorFunc error_func(&xml_errors, &XmlErrorFunc);
-
- // Start up the xml parser with the manifest_xml contents.
- ScopedXmlDocument document(
- xmlParseDoc(reinterpret_cast<const xmlChar*>(response_xml.c_str())));
- if (!document.get()) {
- ParseError("%s", xml_errors.c_str());
- return false;
- }
-
- xmlNode* root = xmlDocGetRootElement(document.get());
- if (!root) {
- ParseError("Missing root node");
- return false;
- }
-
- if (!TagNameEquals(root, "response")) {
- ParseError("Missing response tag");
- return false;
- }
-
- // Check for the response "protocol" attribute.
- const auto protocol = GetAttribute(root, "protocol");
- if (protocol != kProtocolVersion) {
- ParseError(
- "Missing/incorrect protocol on response tag "
- "(expected '%s', found '%s')",
- kProtocolVersion, protocol.c_str());
- return false;
- }
-
- // Parse the first <daystart> if it is present.
- std::vector<xmlNode*> daystarts = GetChildren(root, "daystart");
- if (!daystarts.empty()) {
- xmlNode* first = daystarts[0];
- std::string elapsed_seconds = GetAttribute(first, "elapsed_seconds");
- int parsed_elapsed = kNoDaystart;
- if (base::StringToInt(elapsed_seconds, &parsed_elapsed)) {
- results_.daystart_elapsed_seconds = parsed_elapsed;
- }
- std::string elapsed_days = GetAttribute(first, "elapsed_days");
- parsed_elapsed = kNoDaystart;
- if (base::StringToInt(elapsed_days, &parsed_elapsed)) {
- results_.daystart_elapsed_days = parsed_elapsed;
- }
- }
-
- // Parse each of the <app> tags.
- std::vector<xmlNode*> apps = GetChildren(root, "app");
- for (size_t i = 0; i != apps.size(); ++i) {
- Result result;
- std::string error;
- if (ParseAppTag(apps[i], &result, &error)) {
- results_.list.push_back(result);
- } else {
- ParseError("%s", error.c_str());
- }
- }
-
- return true;
+std::unique_ptr<ProtocolParser> ProtocolParser::Create() {
+ return std::make_unique<ProtocolParserXml>();
}
} // namespace update_client
