UidRanges.cpp revision b1425cc09f8a29350520db0d4f489331df5a689b 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "UidRanges.h"
18
19#include "NetdConstants.h"
20
21#include <stdlib.h>
22
23const std::vector<std::pair<uid_t, uid_t>>& UidRanges::getRanges() const {
24    return mRanges;
25}
26
27bool UidRanges::parseFrom(int argc, char* argv[]) {
28    mRanges.clear();
29    for (int i = 0; i < argc; ++i) {
30        if (!*argv[i]) {
31            // The UID string is empty.
32            return false;
33        }
34        char* endPtr;
35        uid_t uidStart = strtoul(argv[i], &endPtr, 0);
36        uid_t uidEnd;
37        if (!*endPtr) {
38            // Found a single UID. The range contains just the one UID.
39            uidEnd = uidStart;
40        } else if (*endPtr == '-') {
41            if (!*++endPtr) {
42                // Unexpected end of string.
43                return false;
44            }
45            uidEnd = strtoul(endPtr, &endPtr, 0);
46            if (*endPtr) {
47                // Illegal trailing chars.
48                return false;
49            }
50            if (uidEnd < uidStart) {
51                // Invalid order.
52                return false;
53            }
54        } else {
55            // Not a single uid, not a range. Found some other illegal char.
56            return false;
57        }
58        if (uidStart == INVALID_UID || uidEnd == INVALID_UID) {
59            // Invalid UIDs.
60            return false;
61        }
62        mRanges.push_back(std::pair<uid_t, uid_t>(uidStart, uidEnd));
63    }
64    std::sort(mRanges.begin(), mRanges.end());
65    return true;
66}
67
68void UidRanges::add(const UidRanges& other) {
69    auto middle = mRanges.insert(mRanges.end(), other.mRanges.begin(), other.mRanges.end());
70    std::inplace_merge(mRanges.begin(), middle, mRanges.end());
71}
72
73void UidRanges::remove(const UidRanges& other) {
74    auto end = std::set_difference(mRanges.begin(), mRanges.end(), other.mRanges.begin(),
75                                   other.mRanges.end(), mRanges.begin());
76    mRanges.erase(end, mRanges.end());
77}
78