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      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 bool 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 
     45 const std::vector<UidRange>& UidRanges::getRanges() const {
     46     return mRanges;
     47 }
     48 
     49 bool 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 
     90 UidRanges::UidRanges(const std::vector<UidRange>& ranges) {
     91     mRanges = ranges;
     92     std::sort(mRanges.begin(), mRanges.end());
     93 }
     94 
     95 void 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 
    100 void 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 
    106 std::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