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 <inttypes.h>
22#include <limits.h>
23#include <stdlib.h>
24
25#include <android-base/stringprintf.h>
26#include <log/log.h>
27
28using android::base::StringAppendF;
29
30namespace android {
31namespace net {
32
33bool UidRanges::hasUid(uid_t uid) const {
34    if (uid > (unsigned) INT32_MAX) {
35        ALOGW("UID larger than 32 bits: %" PRIu64, static_cast<uint64_t>(uid));
36        return false;
37    }
38    const int32_t intUid = static_cast<int32_t>(uid);
39
40    auto iter = std::lower_bound(mRanges.begin(), mRanges.end(), UidRange(intUid, intUid));
41    return (iter != mRanges.end() && iter->getStart() == intUid) ||
42           (iter != mRanges.begin() && (--iter)->getStop() >= intUid);
43}
44
45const std::vector<UidRange>& UidRanges::getRanges() const {
46    return mRanges;
47}
48
49bool UidRanges::parseFrom(int argc, char* argv[]) {
50    mRanges.clear();
51    for (int i = 0; i < argc; ++i) {
52        if (!*argv[i]) {
53            // The UID string is empty.
54            return false;
55        }
56        char* endPtr;
57        uid_t uidStart = strtoul(argv[i], &endPtr, 0);
58        uid_t uidEnd;
59        if (!*endPtr) {
60            // Found a single UID. The range contains just the one UID.
61            uidEnd = uidStart;
62        } else if (*endPtr == '-') {
63            if (!*++endPtr) {
64                // Unexpected end of string.
65                return false;
66            }
67            uidEnd = strtoul(endPtr, &endPtr, 0);
68            if (*endPtr) {
69                // Illegal trailing chars.
70                return false;
71            }
72            if (uidEnd < uidStart) {
73                // Invalid order.
74                return false;
75            }
76        } else {
77            // Not a single uid, not a range. Found some other illegal char.
78            return false;
79        }
80        if (uidStart == INVALID_UID || uidEnd == INVALID_UID) {
81            // Invalid UIDs.
82            return false;
83        }
84        mRanges.push_back(UidRange(uidStart, uidEnd));
85    }
86    std::sort(mRanges.begin(), mRanges.end());
87    return true;
88}
89
90UidRanges::UidRanges(const std::vector<UidRange>& ranges) {
91    mRanges = ranges;
92    std::sort(mRanges.begin(), mRanges.end());
93}
94
95void UidRanges::add(const UidRanges& other) {
96    auto middle = mRanges.insert(mRanges.end(), other.mRanges.begin(), other.mRanges.end());
97    std::inplace_merge(mRanges.begin(), middle, mRanges.end());
98}
99
100void UidRanges::remove(const UidRanges& other) {
101    auto end = std::set_difference(mRanges.begin(), mRanges.end(), other.mRanges.begin(),
102                                   other.mRanges.end(), mRanges.begin());
103    mRanges.erase(end, mRanges.end());
104}
105
106std::string UidRanges::toString() const {
107    std::string s("UidRanges{ ");
108    for (const auto &range : mRanges) {
109        if (range.length() == 0) {
110            StringAppendF(&s, "<BAD: %u-%u> ", range.getStart(), range.getStop());
111        } else if (range.length() == 1) {
112            StringAppendF(&s, "%u ", range.getStart());
113        } else {
114            StringAppendF(&s, "%u-%u ", range.getStart(), range.getStop());
115        }
116    }
117    StringAppendF(&s, "}");
118    return s;
119}
120
121}  // namespace net
122}  // namespace android
123