1/*
2 * Copyright (c) 2021 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 *     http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16#include <array>
17
18#include "dgram_socket_server.h"
19
20namespace OHOS {
21namespace HiviewDFX {
22int DgramSocketServer::RecvPacket(std::vector<char>& buffer, struct ucred *cred)
23{
24    uint16_t packetLen = 0;
25    if (auto status = Recv(&packetLen, sizeof(packetLen)); status < 0) {
26        return status;
27    }
28    if (packetLen > maxPacketLength) {
29        Recv(&packetLen, sizeof(packetLen), 0); // skip too long packet
30        return 0;
31    }
32
33    std::array<char, CMSG_SPACE(sizeof(struct ucred))> control = {0};
34
35    struct msghdr msgh = {0};
36    int ret = 0;
37    if (cred != nullptr) {
38        struct iovec iov;
39        iov.iov_base = buffer.data();
40        iov.iov_len = packetLen;
41        msgh.msg_iov = &iov;
42        msgh.msg_iovlen = 1;
43
44        msgh.msg_control = control.data();
45        msgh.msg_controllen = control.size();
46
47        msgh.msg_name = nullptr;
48        msgh.msg_namelen = 0;
49        msgh.msg_flags = 0;
50
51        ret = RecvMsg(&msgh);
52    } else {
53        ret = Recv(buffer.data(), packetLen, 0);
54    }
55
56    if (ret <= 0) {
57        return ret;
58    } else if (cred != nullptr) {
59        struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msgh);
60        struct ucred *receivedUcred = (struct ucred*)CMSG_DATA(cmsg);
61        if (receivedUcred == nullptr) {
62            return 0;
63        }
64        *cred = *receivedUcred;
65    }
66    buffer[ret - 1] = 0;
67
68    return ret;
69}
70} // namespace HiviewDFX
71} // namespace OHOS
72