1 files changed, 131 insertions, 0 deletions
diff --git a/packages/google-compute-engine-oslogin/src/nss/nss_oslogin.cc b/packages/google-compute-engine-oslogin/src/nss/nss_oslogin.cc
new file mode 100644
index 0000000..2f6245a
--- /dev/null
+++ b/packages/google-compute-engine-oslogin/src/nss/nss_oslogin.cc
@@ -0,0 +1,131 @@
+// Copyright 2017 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <curl/curl.h>
+#include <errno.h>
+#include <grp.h>
+#include <nss.h>
+#include <pthread.h>
+#include <pwd.h>
+#include <sys/types.h>
+#include <syslog.h>
+#include <unistd.h>
+
+#include <iostream>
+#include <sstream>
+#include <string>
+
+#include <compat.h>
+#include <oslogin_utils.h>
+
+using std::string;
+
+using oslogin_utils::BufferManager;
+using oslogin_utils::HttpGet;
+using oslogin_utils::MutexLock;
+using oslogin_utils::NssCache;
+using oslogin_utils::ParseJsonToPasswd;
+using oslogin_utils::UrlEncode;
+using oslogin_utils::kMetadataServerUrl;
+
+// Size of the NssCache. This also determines how many users will be requested
+// per HTTP call.
+static const uint64_t kNssCacheSize = 2048;
+
+// NssCache for storing passwd entries.
+static NssCache nss_cache(kNssCacheSize);
+
+// Protects access to nss_cache.
+static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+extern "C" {
+
+// Get a passwd entry by id.
+int _nss_oslogin_getpwuid_r(uid_t uid, struct passwd *result, char *buffer,
+                            size_t buflen, int *errnop) {
+  BufferManager buffer_manager(buffer, buflen);
+  std::stringstream url;
+  url << kMetadataServerUrl << "users?uid=" << uid;
+  string response;
+  long http_code = 0;
+  if (!HttpGet(url.str(), &response, &http_code) || http_code != 200 ||
+      response.empty()) {
+    *errnop = ENOENT;
+    return NSS_STATUS_NOTFOUND;
+  }
+  if (!ParseJsonToPasswd(response, result, &buffer_manager, errnop)) {
+    if (*errnop == EINVAL) {
+      openlog("nss_oslogin", LOG_PID, LOG_USER);
+      syslog(LOG_ERR, "Received malformed response from server: %s",
+             response.c_str());
+      closelog();
+    }
+    return *errnop == ERANGE ? NSS_STATUS_TRYAGAIN : NSS_STATUS_NOTFOUND;
+  }
+  return NSS_STATUS_SUCCESS;
+}
+
+// Get a passwd entry by name.
+int _nss_oslogin_getpwnam_r(const char *name, struct passwd *result,
+                            char *buffer, size_t buflen, int *errnop) {
+  BufferManager buffer_manager(buffer, buflen);
+  std::stringstream url;
+  url << kMetadataServerUrl << "users?username=" << UrlEncode(name);
+  string response;
+  long http_code = 0;
+  if (!HttpGet(url.str(), &response, &http_code) || http_code != 200 ||
+      response.empty()) {
+    *errnop = ENOENT;
+    return NSS_STATUS_NOTFOUND;
+  }
+  if (!ParseJsonToPasswd(response, result, &buffer_manager, errnop)) {
+    if (*errnop == EINVAL) {
+      openlog("nss_oslogin", LOG_PID, LOG_USER);
+      syslog(LOG_ERR, "Received malformed response from server: %s",
+             response.c_str());
+      closelog();
+    }
+    return *errnop == ERANGE ? NSS_STATUS_TRYAGAIN : NSS_STATUS_NOTFOUND;
+  }
+  return NSS_STATUS_SUCCESS;
+}
+
+// nss_getpwent_r() is intentionally left unimplemented. This functionality is
+// now covered by the nss_cache binary and nss_cache module.
+
+nss_status _nss_oslogin_getpwent_r() { return NSS_STATUS_NOTFOUND; }
+nss_status _nss_oslogin_endpwent() { return NSS_STATUS_SUCCESS; }
+nss_status _nss_oslogin_setpwent() { return NSS_STATUS_SUCCESS; }
+
+NSS_METHOD_PROTOTYPE(__nss_compat_getpwnam_r);
+NSS_METHOD_PROTOTYPE(__nss_compat_getpwuid_r);
+NSS_METHOD_PROTOTYPE(__nss_compat_getpwent_r);
+NSS_METHOD_PROTOTYPE(__nss_compat_setpwent);
+NSS_METHOD_PROTOTYPE(__nss_compat_endpwent);
+
+DECLARE_NSS_METHOD_TABLE(methods,
+    { NSDB_PASSWD, "getpwnam_r", __nss_compat_getpwnam_r,
+      (void*)_nss_oslogin_getpwnam_r },
+    { NSDB_PASSWD, "getpwuid_r", __nss_compat_getpwuid_r,
+      (void*)_nss_oslogin_getpwuid_r },
+    { NSDB_PASSWD, "getpwent_r", __nss_compat_getpwent_r,
+      (void*)_nss_oslogin_getpwent_r },
+    { NSDB_PASSWD, "endpwent",   __nss_compat_endpwent,
+      (void*)_nss_oslogin_endpwent },
+    { NSDB_PASSWD, "setpwent",   __nss_compat_setpwent,
+      (void*)_nss_oslogin_setpwent },
+)
+
+NSS_REGISTER_METHODS(methods)
+}  // extern "C"