summaryrefslogtreecommitdiffstats
path: root/adb/adb_io.cpp
blob: ae168340802ff372f1d16a886a3686fc5ab8d765 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define TRACE_TAG RWX

#include "adb_io.h"

#include <unistd.h>

#include <android-base/stringprintf.h>

#include "adb.h"
#include "adb_trace.h"
#include "adb_utils.h"
#include "sysdeps.h"

bool SendProtocolString(int fd, const std::string& s) {
    unsigned int length = s.size();
    if (length > MAX_PAYLOAD_V1 - 4) {
        errno = EMSGSIZE;
        return false;
    }

    // The cost of sending two strings outweighs the cost of formatting.
    // "adb sync" performance is affected by this.
    return WriteFdFmt(fd, "%04x%.*s", length, length, s.c_str());
}

bool ReadProtocolString(int fd, std::string* s, std::string* error) {
    char buf[5];
    if (!ReadFdExactly(fd, buf, 4)) {
        *error = perror_str("protocol fault (couldn't read status length)");
        return false;
    }
    buf[4] = 0;

    unsigned long len = strtoul(buf, 0, 16);
    s->resize(len, '\0');
    if (!ReadFdExactly(fd, &(*s)[0], len)) {
        *error = perror_str("protocol fault (couldn't read status message)");
        return false;
    }

    return true;
}

bool SendOkay(int fd) {
    return WriteFdExactly(fd, "OKAY", 4);
}

bool SendFail(int fd, const std::string& reason) {
    return WriteFdExactly(fd, "FAIL", 4) && SendProtocolString(fd, reason);
}

bool ReadFdExactly(int fd, void* buf, size_t len) {
    char* p = reinterpret_cast<char*>(buf);

    size_t len0 = len;

    D("readx: fd=%d wanted=%zu", fd, len);
    while (len > 0) {
        int r = adb_read(fd, p, len);
        if (r > 0) {
            len -= r;
            p += r;
        } else if (r == -1) {
            D("readx: fd=%d error %d: %s", fd, errno, strerror(errno));
            return false;
        } else {
            D("readx: fd=%d disconnected", fd);
            errno = 0;
            return false;
        }
    }

    VLOG(RWX) << "readx: fd=" << fd << " wanted=" << len0 << " got=" << (len0 - len)
              << " " << dump_hex(reinterpret_cast<const unsigned char*>(buf), len0);

    return true;
}

bool WriteFdExactly(int fd, const void* buf, size_t len) {
    const char* p = reinterpret_cast<const char*>(buf);
    int r;

    VLOG(RWX) << "writex: fd=" << fd << " len=" << len
              << " " << dump_hex(reinterpret_cast<const unsigned char*>(buf), len);

    while (len > 0) {
        r = adb_write(fd, p, len);
        if (r == -1) {
            D("writex: fd=%d error %d: %s", fd, errno, strerror(errno));
            if (errno == EAGAIN) {
                adb_sleep_ms(1); // just yield some cpu time
                continue;
            } else if (errno == EPIPE) {
                D("writex: fd=%d disconnected", fd);
                errno = 0;
                return false;
            } else {
                return false;
            }
        } else {
            len -= r;
            p += r;
        }
    }
    return true;
}

bool WriteFdExactly(int fd, const char* str) {
    return WriteFdExactly(fd, str, strlen(str));
}

bool WriteFdExactly(int fd, const std::string& str) {
    return WriteFdExactly(fd, str.c_str(), str.size());
}

bool WriteFdFmt(int fd, const char* fmt, ...) {
    std::string str;

    va_list ap;
    va_start(ap, fmt);
    android::base::StringAppendV(&str, fmt, ap);
    va_end(ap);

    return WriteFdExactly(fd, str);
}

bool ReadOrderlyShutdown(int fd) {
    char buf[16];

    // Only call this function if you're sure that the peer does
    // orderly/graceful shutdown of the socket, closing the socket so that
    // adb_read() will return 0. If the peer keeps the socket open, adb_read()
    // will never return.
    int result = adb_read(fd, buf, sizeof(buf));
    if (result == -1) {
        // If errno is EAGAIN, that means this function was called on a
        // nonblocking socket and it would have blocked (which would be bad
        // because we'd probably block the main thread where nonblocking IO is
        // done). Don't do that. If you have a nonblocking socket, use the
        // fdevent APIs to get called on FDE_READ, and then call this function
        // if you really need to, but it shouldn't be needed for server sockets.
        CHECK_NE(errno, EAGAIN);

        // Note that on Windows, orderly shutdown sometimes causes
        // recv() == SOCKET_ERROR && WSAGetLastError() == WSAECONNRESET. That
        // can be ignored.
        return false;
    } else if (result == 0) {
        // Peer has performed an orderly/graceful shutdown.
        return true;
    } else {
        // Unexpectedly received data. This is essentially a protocol error
        // because you should not call this function unless you expect no more
        // data. We don't repeatedly call adb_read() until we get zero because
        // we don't know how long that would take, but we do know that the
        // caller wants to close the socket soon.
        VLOG(RWX) << "ReadOrderlyShutdown(" << fd << ") unexpectedly read "
                  << dump_hex(buf, result);
        // Shutdown the socket to prevent the caller from reading or writing to
        // it which doesn't make sense if we just read and discarded some data.
        adb_shutdown(fd);
        errno = EINVAL;
        return false;
    }
}