init: support setting rlimits per service

Add a new service option, `rlimit` that allows a given rlimit to be
set for a specific service instead of globally.

Use the same parsing, now allowing text such as 'cpu' or 'rtprio'
instead of relying on the enum value for the `setrlimit` builtin
command as well.

Bug: 63882119
Bug: 64894637

Test: boot bullhead, run a test app that attempts to set its rtprio to
      95, see that the priority set fails normally but passes when
      `rlimit rtprio 99 99` is used as its service option.
      See that this fails when `rlimit rtprio 50 50` is used as well.
Test: new unit tests

Change-Id: I4a13ca20e8529937d8b4bc11718ffaaf77523a52

1 files changed, 78 insertions, 0 deletions

diff --git a/init/rlimit_parser.cpp b/init/rlimit_parser.cpp
new file mode 100644
index 000000000..fe1d6a724
--- /dev/null
+++ b/init/rlimit_parser.cpp
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * 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 "rlimit_parser.h"
+
+#include <android-base/parseint.h>
+#include <android-base/strings.h>
+
+using android::base::EqualsIgnoreCase;
+using android::base::ParseInt;
+using android::base::ParseUint;
+using android::base::StartsWith;
+
+namespace android {
+namespace init {
+
+// Builtins and service definitions both have their arguments start at 1 and finish at 3.
+Result<std::pair<int, rlimit>> ParseRlimit(const std::vector<std::string>& args) {
+    static const std::vector<std::pair<const char*, int>> text_to_resources = {
+        {"cpu", 0},       {"fsize", 1}, {"data", 2},    {"stack", 3},
+        {"core", 4},      {"rss", 5},   {"nproc", 6},   {"nofile", 7},
+        {"memlock", 8},   {"as", 9},    {"locks", 10},  {"sigpending", 11},
+        {"msgqueue", 12}, {"nice", 13}, {"rtprio", 14}, {"rttime", 15},
+    };
+
+    int resource;
+
+    if (ParseInt(args[1], &resource)) {
+        if (resource >= RLIM_NLIMITS) {
+            return Error() << "Resource '" << args[1] << "' over the maximum resource value '"
+                           << RLIM_NLIMITS << "'";
+        } else if (resource < 0) {
+            return Error() << "Resource '" << args[1] << "' below the minimum resource value '0'";
+        }
+    } else {
+        std::string resource_string;
+        if (StartsWith(args[1], "RLIM_")) {
+            resource_string = args[1].substr(5);
+        } else {
+            resource_string = args[1];
+        }
+
+        auto it = std::find_if(text_to_resources.begin(), text_to_resources.end(),
+                               [&resource_string](const auto& entry) {
+                                   return EqualsIgnoreCase(resource_string, entry.first);
+                               });
+        if (it == text_to_resources.end()) {
+            return Error() << "Could not parse resource '" << args[1] << "'";
+        }
+
+        resource = it->second;
+    }
+
+    rlimit limit;
+    if (!ParseUint(args[2], &limit.rlim_cur)) {
+        return Error() << "Could not parse soft limit '" << args[2] << "'";
+    }
+    if (!ParseUint(args[3], &limit.rlim_max)) {
+        return Error() << "Could not parse hard limit '" << args[3] << "'";
+    }
+    return {resource, limit};
+}
+
+}  // namespace init
+}  // namespace android