summaryrefslogtreecommitdiffstats
path: root/wsrep-lib/wsrep-API/v26/wsrep_loader.c
blob: cfa1984f97bdb0174f12d7ba2c4bed051d854b22 (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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
/* Copyright (C) 2009-2011 Codership Oy <info@codersihp.com>

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/*! @file wsrep implementation loader */

#include <dlfcn.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>

#include "wsrep_api.h"

// Logging stuff for the loader
static const char* log_levels[] = {"FATAL", "ERROR", "WARN", "INFO", "DEBUG"};

static void default_logger (wsrep_log_level_t lvl, const char* msg)
{
    fprintf (stderr, "wsrep loader: [%s] %s\n", log_levels[lvl], msg);
}

static wsrep_log_cb_t logger = default_logger;

/**************************************************************************
 * Library loader
 **************************************************************************/

static int wsrep_check_iface_version(const char* found, const char* iface_ver)
{
    const size_t msg_len = 128;
    char msg[128];

    if (strcmp(found, iface_ver)) {
        snprintf (msg, msg_len,
                  "provider interface version mismatch: need '%s', found '%s'",
                  iface_ver, found);
        logger (WSREP_LOG_ERROR, msg);
        return EINVAL;
    }

    return 0;
}

static int verify(const wsrep_t *wh, const char *iface_ver)
{
    char msg[128];
    const size_t msg_len = sizeof(msg);

#define VERIFY(_p) if (!(_p)) {                                       \
        snprintf(msg, msg_len, "wsrep_load(): verify(): %s\n", # _p); \
        logger (WSREP_LOG_ERROR, msg);                                \
        return EINVAL;                                                \
    }

    VERIFY(wh);
    VERIFY(wh->version);

    if (wsrep_check_iface_version(wh->version, iface_ver))
        return EINVAL;

    VERIFY(wh->init);
    VERIFY(wh->options_set);
    VERIFY(wh->options_get);
    VERIFY(wh->enc_set_key);
    VERIFY(wh->connect);
    VERIFY(wh->disconnect);
    VERIFY(wh->recv);
    VERIFY(wh->assign_read_view);
    VERIFY(wh->certify);
    VERIFY(wh->commit_order_enter);
    VERIFY(wh->commit_order_leave);
    VERIFY(wh->release);
    VERIFY(wh->replay_trx);
    VERIFY(wh->abort_certification);
    VERIFY(wh->append_key);
    VERIFY(wh->append_data);
    VERIFY(wh->free_connection);
    VERIFY(wh->to_execute_start);
    VERIFY(wh->to_execute_end);
    VERIFY(wh->preordered_collect);
    VERIFY(wh->preordered_commit);
    VERIFY(wh->sst_sent);
    VERIFY(wh->sst_received);
    VERIFY(wh->stats_get);
    VERIFY(wh->stats_free);
    VERIFY(wh->stats_reset);
    VERIFY(wh->pause);
    VERIFY(wh->resume);
    VERIFY(wh->desync);
    VERIFY(wh->resync);
    VERIFY(wh->lock);
    VERIFY(wh->unlock);
    VERIFY(wh->is_locked);
    VERIFY(wh->provider_name);
    VERIFY(wh->provider_version);
    VERIFY(wh->provider_vendor);
    VERIFY(wh->free);
    return 0;
}

typedef int (*wsrep_loader_fun)(wsrep_t*);

static wsrep_loader_fun wsrep_dlf(void *dlh, const char *sym)
{
    union {
        wsrep_loader_fun dlfun;
        void *obj;
    } alias;
    alias.obj = dlsym(dlh, sym);
    return alias.dlfun;
}

static int wsrep_check_version_symbol(void *dlh)
{
    char** dlversion = NULL;
    dlversion = (char**) dlsym(dlh, "wsrep_interface_version");
    if (dlversion == NULL)
        return 0;
    return wsrep_check_iface_version(*dlversion, WSREP_INTERFACE_VERSION);
}

extern int wsrep_dummy_loader(wsrep_t *w);

int wsrep_load(const char *spec, wsrep_t **hptr, wsrep_log_cb_t log_cb)
{
    int ret = 0;
    void *dlh = NULL;
    wsrep_loader_fun dlfun;
    char msg[1024];
    const size_t msg_len = sizeof(msg) - 1;
    msg[msg_len] = 0;

    if (NULL != log_cb)
        logger = log_cb;

    if (!(spec && hptr))
        return EINVAL;

    snprintf (msg, msg_len,
              "wsrep_load(): loading provider library '%s'", spec);
    logger (WSREP_LOG_INFO, msg);

    if (!(*hptr = malloc(sizeof(wsrep_t)))) {
        logger (WSREP_LOG_FATAL, "wsrep_load(): out of memory");
        return ENOMEM;
    }

    if (!spec || strcmp(spec, WSREP_NONE) == 0) {
        if ((ret = wsrep_dummy_loader(*hptr)) != 0) {
            free (*hptr);
            *hptr = NULL;
        }
        return ret;
    }

    if (!(dlh = dlopen(spec, RTLD_NOW | RTLD_LOCAL))) {
        snprintf(msg, msg_len, "wsrep_load(): dlopen(): %s", dlerror());
        logger (WSREP_LOG_ERROR, msg);
        ret = EINVAL;
        goto out;
    }

    if (!(dlfun = wsrep_dlf(dlh, "wsrep_loader"))) {
        ret = EINVAL;
        goto out;
    }

    if (wsrep_check_version_symbol(dlh) != 0) {
        ret = EINVAL;
        goto out;
    }

    if ((ret = (*dlfun)(*hptr)) != 0) {
        snprintf(msg, msg_len, "wsrep_load(): loader failed: %s",
                 strerror(ret));
        logger (WSREP_LOG_ERROR, msg);
        goto out;
    }

    if ((ret = verify(*hptr, WSREP_INTERFACE_VERSION)) != 0) {
        snprintf (msg, msg_len,
                  "wsrep_load(): interface version mismatch: my version %s, "
                  "provider version %s", WSREP_INTERFACE_VERSION,
                  (*hptr)->version);
        logger (WSREP_LOG_ERROR, msg);
        goto out;
    }

    (*hptr)->dlh = dlh;

out:
    if (ret != 0) {
        if (dlh) dlclose(dlh);
        free(*hptr);
        *hptr = NULL;
    } else {
        snprintf (msg, msg_len,
                  "wsrep_load(): %s %s by %s loaded successfully.",
                  (*hptr)->provider_name, (*hptr)->provider_version,
                  (*hptr)->provider_vendor);
        logger (WSREP_LOG_INFO, msg);
    }

    return ret;
}

void wsrep_unload(wsrep_t *hptr)
{
    if (!hptr) {
        logger (WSREP_LOG_WARN, "wsrep_unload(): null pointer.");
    } else {
        if (hptr->free)
            hptr->free(hptr);
        if (hptr->dlh)
        {
            int err;
            if ((err = dlclose(hptr->dlh)))
            {
                char msg[1024];
                snprintf(msg, sizeof(msg), "dlclose(): %s", dlerror());
                msg[sizeof(msg) - 1] = '\0';
                logger(WSREP_LOG_WARN, msg);
            }
        }
        free(hptr);
    }
}