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
28 using android::base::StringAppendF;
29
30 namespace android {
31 namespace net {
32
33 namespace {
34
compUidRangeParcel(const UidRangeParcel & lhs,const UidRangeParcel & rhs)35 bool compUidRangeParcel(const UidRangeParcel& lhs, const UidRangeParcel& rhs) {
36 return lhs.start != rhs.start ? (lhs.start < rhs.start) : (lhs.stop < rhs.stop);
37 };
38
makeUidRangeParcel(int start,int stop)39 UidRangeParcel makeUidRangeParcel(int start, int stop) {
40 UidRangeParcel res;
41 res.start = start;
42 res.stop = stop;
43
44 return res;
45 }
46
length(const UidRangeParcel & t)47 uint32_t length(const UidRangeParcel& t) {
48 if (t.start == -1 || t.stop == -1) {
49 return 0;
50 }
51 return static_cast<uint32_t>(t.stop - t.start + 1);
52 }
53
54 } // namespace
55
hasUid(uid_t uid) const56 bool UidRanges::hasUid(uid_t uid) const {
57 if (uid > (unsigned) INT32_MAX) {
58 ALOGW("UID larger than 32 bits: %" PRIu64, static_cast<uint64_t>(uid));
59 return false;
60 }
61 const int32_t intUid = static_cast<int32_t>(uid);
62
63 auto iter = std::lower_bound(mRanges.begin(), mRanges.end(), makeUidRangeParcel(intUid, intUid),
64 compUidRangeParcel);
65 return (iter != mRanges.end() && iter->start == intUid) ||
66 (iter != mRanges.begin() && (--iter)->stop >= intUid);
67 }
68
getRanges() const69 const std::vector<UidRangeParcel>& UidRanges::getRanges() const {
70 return mRanges;
71 }
72
parseFrom(int argc,char * argv[])73 bool UidRanges::parseFrom(int argc, char* argv[]) {
74 mRanges.clear();
75 for (int i = 0; i < argc; ++i) {
76 if (!*argv[i]) {
77 // The UID string is empty.
78 return false;
79 }
80 char* endPtr;
81 uid_t uidStart = strtoul(argv[i], &endPtr, 0);
82 uid_t uidEnd;
83 if (!*endPtr) {
84 // Found a single UID. The range contains just the one UID.
85 uidEnd = uidStart;
86 } else if (*endPtr == '-') {
87 if (!*++endPtr) {
88 // Unexpected end of string.
89 return false;
90 }
91 uidEnd = strtoul(endPtr, &endPtr, 0);
92 if (*endPtr) {
93 // Illegal trailing chars.
94 return false;
95 }
96 if (uidEnd < uidStart) {
97 // Invalid order.
98 return false;
99 }
100 } else {
101 // Not a single uid, not a range. Found some other illegal char.
102 return false;
103 }
104 if (uidStart == INVALID_UID || uidEnd == INVALID_UID) {
105 // Invalid UIDs.
106 return false;
107 }
108 mRanges.push_back(makeUidRangeParcel(uidStart, uidEnd));
109 }
110 std::sort(mRanges.begin(), mRanges.end(), compUidRangeParcel);
111 return true;
112 }
113
UidRanges(const std::vector<UidRangeParcel> & ranges)114 UidRanges::UidRanges(const std::vector<UidRangeParcel>& ranges) {
115 mRanges = ranges;
116 std::sort(mRanges.begin(), mRanges.end(), compUidRangeParcel);
117 }
118
add(const UidRanges & other)119 void UidRanges::add(const UidRanges& other) {
120 auto middle = mRanges.insert(mRanges.end(), other.mRanges.begin(), other.mRanges.end());
121 std::inplace_merge(mRanges.begin(), middle, mRanges.end(), compUidRangeParcel);
122 }
123
remove(const UidRanges & other)124 void UidRanges::remove(const UidRanges& other) {
125 auto end = std::set_difference(mRanges.begin(), mRanges.end(), other.mRanges.begin(),
126 other.mRanges.end(), mRanges.begin(), compUidRangeParcel);
127 mRanges.erase(end, mRanges.end());
128 }
129
isOverlapped(const UidRangeParcel & r1,const UidRangeParcel & r2) const130 bool UidRanges::isOverlapped(const UidRangeParcel& r1, const UidRangeParcel& r2) const {
131 return (r1.stop >= r2.start) && (r1.start <= r2.stop);
132 }
133
overlapsSelf() const134 bool UidRanges::overlapsSelf() const {
135 // Compare each element one by one
136 for (size_t i = 0; i < mRanges.size(); i++) {
137 for (size_t j = i + 1; j < mRanges.size(); j++) {
138 if (isOverlapped(mRanges[i], mRanges[j])) {
139 return true;
140 }
141 }
142 }
143 return false;
144 }
145
overlaps(const UidRanges & other) const146 bool UidRanges::overlaps(const UidRanges& other) const {
147 for (const auto& thisRange : mRanges) {
148 for (const auto& inputRange : other.getRanges()) {
149 if (isOverlapped(thisRange, inputRange)) {
150 return true;
151 }
152 }
153 }
154 return false;
155 }
156
toString() const157 std::string UidRanges::toString() const {
158 std::string s("uids{ ");
159 for (const auto &range : mRanges) {
160 if (length(range) == 0) {
161 StringAppendF(&s, "<BAD: %u-%u> ", range.start, range.stop);
162 } else if (length(range) == 1) {
163 StringAppendF(&s, "%u ", range.start);
164 } else {
165 StringAppendF(&s, "%u-%u ", range.start, range.stop);
166 }
167 }
168 StringAppendF(&s, "}");
169 return s;
170 }
171
172 } // namespace net
173 } // namespace android
174