summaryrefslogtreecommitdiffstats
path: root/migration/qemu-file-stdio.c
blob: f402e8f7080e7ea7683834a285401139bcb1d416 (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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/*
 * QEMU System Emulator
 *
 * Copyright (c) 2003-2008 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qemu/coroutine.h"
#include "migration/qemu-file.h"

typedef struct QEMUFileStdio {
    FILE *stdio_file;
    QEMUFile *file;
} QEMUFileStdio;

static int stdio_get_fd(void *opaque)
{
    QEMUFileStdio *s = opaque;

    return fileno(s->stdio_file);
}

static ssize_t stdio_put_buffer(void *opaque, const uint8_t *buf, int64_t pos,
                                size_t size)
{
    QEMUFileStdio *s = opaque;
    size_t res;

    res = fwrite(buf, 1, size, s->stdio_file);

    if (res != size) {
        return -errno;
    }
    return res;
}

static ssize_t stdio_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
                                size_t size)
{
    QEMUFileStdio *s = opaque;
    FILE *fp = s->stdio_file;
    ssize_t bytes;

    for (;;) {
        clearerr(fp);
        bytes = fread(buf, 1, size, fp);
        if (bytes != 0 || !ferror(fp)) {
            break;
        }
        if (errno == EAGAIN) {
            yield_until_fd_readable(fileno(fp));
        } else if (errno != EINTR) {
            break;
        }
    }
    return bytes;
}

static int stdio_pclose(void *opaque)
{
    QEMUFileStdio *s = opaque;
    int ret;
    ret = pclose(s->stdio_file);
    if (ret == -1) {
        ret = -errno;
    } else if (!WIFEXITED(ret) || WEXITSTATUS(ret) != 0) {
        /* close succeeded, but non-zero exit code: */
        ret = -EIO; /* fake errno value */
    }
    g_free(s);
    return ret;
}

static int stdio_fclose(void *opaque)
{
    QEMUFileStdio *s = opaque;
    int ret = 0;

    if (qemu_file_is_writable(s->file)) {
        int fd = fileno(s->stdio_file);
        struct stat st;

        ret = fstat(fd, &st);
        if (ret == 0 && S_ISREG(st.st_mode)) {
            /*
             * If the file handle is a regular file make sure the
             * data is flushed to disk before signaling success.
             */
            ret = fsync(fd);
            if (ret != 0) {
                ret = -errno;
                return ret;
            }
        }
    }
    if (fclose(s->stdio_file) == EOF) {
        ret = -errno;
    }
    g_free(s);
    return ret;
}

static const QEMUFileOps stdio_pipe_read_ops = {
    .get_fd =     stdio_get_fd,
    .get_buffer = stdio_get_buffer,
    .close =      stdio_pclose
};

static const QEMUFileOps stdio_pipe_write_ops = {
    .get_fd =     stdio_get_fd,
    .put_buffer = stdio_put_buffer,
    .close =      stdio_pclose
};

QEMUFile *qemu_popen_cmd(const char *command, const char *mode)
{
    FILE *stdio_file;
    QEMUFileStdio *s;

    if (mode == NULL || (mode[0] != 'r' && mode[0] != 'w') || mode[1] != 0) {
        fprintf(stderr, "qemu_popen: Argument validity check failed\n");
        return NULL;
    }

    stdio_file = popen(command, mode);
    if (stdio_file == NULL) {
        return NULL;
    }

    s = g_new0(QEMUFileStdio, 1);

    s->stdio_file = stdio_file;

    if (mode[0] == 'r') {
        s->file = qemu_fopen_ops(s, &stdio_pipe_read_ops);
    } else {
        s->file = qemu_fopen_ops(s, &stdio_pipe_write_ops);
    }
    return s->file;
}

static const QEMUFileOps stdio_file_read_ops = {
    .get_fd =     stdio_get_fd,
    .get_buffer = stdio_get_buffer,
    .close =      stdio_fclose
};

static const QEMUFileOps stdio_file_write_ops = {
    .get_fd =     stdio_get_fd,
    .put_buffer = stdio_put_buffer,
    .close =      stdio_fclose
};

QEMUFile *qemu_fopen(const char *filename, const char *mode)
{
    QEMUFileStdio *s;

    if (qemu_file_mode_is_not_valid(mode)) {
        return NULL;
    }

    s = g_new0(QEMUFileStdio, 1);

    s->stdio_file = fopen(filename, mode);
    if (!s->stdio_file) {
        goto fail;
    }

    if (mode[0] == 'w') {
        s->file = qemu_fopen_ops(s, &stdio_file_write_ops);
    } else {
        s->file = qemu_fopen_ops(s, &stdio_file_read_ops);
    }
    return s->file;
fail:
    g_free(s);
    return NULL;
}
OpenPOWER on IntegriCloud