summaryrefslogtreecommitdiff
path: root/server/providers/data_provider_fo.c
blob: 7d0240489c643d2fb9183ac520d98ba6f4d08bc9 (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
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
/*
    SSSD

    Data Provider Helpers

    Copyright (C) Simo Sorce <ssorce@redhat.com> 2009

    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; either version 3 of the License, or
    (at your option) any later version.

    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, see <http://www.gnu.org/licenses/>.
*/

#include <netdb.h>
#include <arpa/inet.h>
#include "providers/dp_backend.h"
#include "resolv/async_resolv.h"

struct be_svc_callback {
    struct be_svc_callback *prev;
    struct be_svc_callback *next;

    struct be_svc_data *svc;

    be_svc_callback_fn_t *fn;
    void *private_data;
};

struct be_svc_data {
    struct be_svc_data *prev;
    struct be_svc_data *next;

    const char *name;
    struct fo_service *fo_service;

    struct fo_server *last_good_srv;

    struct be_svc_callback *callbacks;
};

struct be_failover_ctx {
    struct fo_ctx *fo_ctx;
    struct resolv_ctx *resolv;

    struct be_svc_data *svcs;
};

int be_init_failover(struct be_ctx *ctx)
{
    int ret;

    if (ctx->be_fo != NULL) {
        return EOK;
    }

    ctx->be_fo = talloc_zero(ctx, struct be_failover_ctx);
    if (!ctx->be_fo) {
        return ENOMEM;
    }

    ret = resolv_init(ctx, ctx->ev, 5, &ctx->be_fo->resolv);
    if (ret != EOK) {
        talloc_zfree(ctx->be_fo);
        return ret;
    }

    /* todo get timeout from configuration */
    ctx->be_fo->fo_ctx = fo_context_init(ctx->be_fo, 30);
    if (!ctx->be_fo->fo_ctx) {
        talloc_zfree(ctx->be_fo);
        return ENOMEM;
    }

    return EOK;
}

static int be_svc_data_destroy(void *memptr)
{
    struct be_svc_data *svc;

    svc = talloc_get_type(memptr, struct be_svc_data);

    while (svc->callbacks) {
        /* callbacks removes themselves from the list,
         * so this while will freem them all and then terminate */
        talloc_free(svc->callbacks);
    }

    return 0;
}

int be_fo_add_service(struct be_ctx *ctx, const char *service_name)
{
    struct fo_service *service;
    struct be_svc_data *svc;
    int ret;

    DLIST_FOR_EACH(svc, ctx->be_fo->svcs) {
        if (strcmp(svc->name, service_name) == 0) {
            DEBUG(6, ("Failover service already initialized!\n"));
            /* we already have a service up and configured,
             * can happen when using both id and auth provider
             */
            return EOK;
        }
    }

    /* if not in the be service list, try to create new one */

    ret = fo_new_service(ctx->be_fo->fo_ctx, service_name, &service);
    if (ret != EOK && ret != EEXIST) {
        DEBUG(1, ("Failed to create failover service!\n"));
        return ret;
    }

    svc = talloc_zero(ctx->be_fo, struct be_svc_data);
    if (!svc) {
        return ENOMEM;
    }
    talloc_set_destructor((TALLOC_CTX *)svc, be_svc_data_destroy);

    svc->name = talloc_strdup(svc, service_name);
    if (!svc->name) {
        talloc_zfree(svc);
        return ENOMEM;
    }
    svc->fo_service = service;

    DLIST_ADD(ctx->be_fo->svcs, svc);

    return EOK;
}

static int be_svc_callback_destroy(void *memptr)
{
    struct be_svc_callback *callback;

    callback = talloc_get_type(memptr, struct be_svc_callback);

    if (callback->svc) {
        DLIST_REMOVE(callback->svc->callbacks, callback);
    }

    return 0;
}

int be_fo_service_add_callback(TALLOC_CTX *memctx,
                               struct be_ctx *ctx, const char *service_name,
                               be_svc_callback_fn_t *fn, void *private_data)
{
    struct be_svc_callback *callback;
    struct be_svc_data *svc;

    DLIST_FOR_EACH(svc, ctx->be_fo->svcs) {
        if (strcmp(svc->name, service_name) == 0) {
            break;
        }
    }
    if (NULL == svc) {
        return ENOENT;
    }

    callback = talloc_zero(memctx, struct be_svc_callback);
    if (!callback) {
        return ENOMEM;
    }
    talloc_set_destructor((TALLOC_CTX *)callback, be_svc_callback_destroy);

    callback->svc = svc;
    callback->fn = fn;
    callback->private_data = private_data;

    DLIST_ADD(svc->callbacks, callback);

    return EOK;
}

int be_fo_add_server(struct be_ctx *ctx, const char *service_name,
                     const char *server, int port, void *user_data)
{
    struct be_svc_data *svc;
    int ret;

    DLIST_FOR_EACH(svc, ctx->be_fo->svcs) {
        if (strcmp(svc->name, service_name) == 0) {
            break;
        }
    }
    if (NULL == svc) {
        return ENOENT;
    }

    ret = fo_add_server(svc->fo_service, server, port, user_data);
    if (ret && ret != EEXIST) {
        DEBUG(1, ("Failed to add server to failover service\n"));
        return ret;
    }

    return EOK;
}

struct be_resolve_server_state {
    struct tevent_context *ev;
    struct be_ctx *ctx;

    struct be_svc_data *svc;
    int attempts;

    struct fo_server *srv;
};

static void be_resolve_server_done(struct tevent_req *subreq);

struct tevent_req *be_resolve_server_send(TALLOC_CTX *memctx,
                                          struct tevent_context *ev,
                                          struct be_ctx *ctx,
                                          const char *service_name)
{
    struct tevent_req *req, *subreq;
    struct be_resolve_server_state *state;
    struct be_svc_data *svc;

    req = tevent_req_create(memctx, &state, struct be_resolve_server_state);
    if (!req) return NULL;

    state->ev = ev;
    state->ctx = ctx;

    DLIST_FOR_EACH(svc, ctx->be_fo->svcs) {
        if (strcmp(svc->name, service_name) == 0) {
            state->svc = svc;
            break;
        }
    }

    if (NULL == svc) {
        tevent_req_error(req, EINVAL);
        tevent_req_post(req, ev);
        return req;
    }

    state->attempts = 0;

    subreq = fo_resolve_service_send(state, ev,
                                     ctx->be_fo->resolv, svc->fo_service);
    if (!subreq) {
        talloc_zfree(req);
        return NULL;
    }
    tevent_req_set_callback(subreq, be_resolve_server_done, req);

    return req;
}

static void be_resolve_server_done(struct tevent_req *subreq)
{
    struct tevent_req *req = tevent_req_callback_data(subreq,
                                                      struct tevent_req);
    struct be_resolve_server_state *state = tevent_req_data(req,
                                             struct be_resolve_server_state);
    struct be_svc_callback *callback;
    int ret;

    ret = fo_resolve_service_recv(subreq, &state->srv);
    talloc_zfree(subreq);
    switch (ret) {
    case EOK:
        if (!state->srv) {
            tevent_req_error(req, EFAULT);
            return;
        }
        break;

    case ENOENT:
        /* all servers have been tried and none
         * was found good, go offline */
        tevent_req_error(req, EIO);
        return;

    default:
        /* mark server as bad and retry */
        if (!state->srv) {
            tevent_req_error(req, EFAULT);
            return;
        }
        DEBUG(6, ("Couldn't resolve server (%s), resolver returned (%d)\n",
                  fo_get_server_name(state->srv), ret));

        state->attempts++;
        if (state->attempts >= 10) {
            DEBUG(2, ("Failed to find a server after 10 attempts\n"));
            tevent_req_error(req, EIO);
            return;
        }

        /* now try next one */
        DEBUG(6, ("Trying with the next one!\n"));
        subreq = fo_resolve_service_send(state, state->ev,
                                         state->ctx->be_fo->resolv,
                                         state->svc->fo_service);
        if (!subreq) {
            tevent_req_error(req, ENOMEM);
            return;
        }
        tevent_req_set_callback(subreq, be_resolve_server_done, req);

        return;
    }

    /* all fine we got the server */

    if (debug_level >= 4) {
        struct hostent *srvaddr;
        char ipaddr[128];
        srvaddr = fo_get_server_hostent(state->srv);
        inet_ntop(srvaddr->h_addrtype, srvaddr->h_addr_list[0],
                  ipaddr, 128);

        DEBUG(4, ("Found address for server %s: [%s]\n",
                  fo_get_server_name(state->srv), ipaddr));
    }

    /* now call all svc callbacks if server changed */
    if (state->srv != state->svc->last_good_srv) {
        state->svc->last_good_srv = state->srv;

        DLIST_FOR_EACH(callback, state->svc->callbacks) {
            callback->fn(callback->private_data, state->srv);
        }
    }

    tevent_req_done(req);
}

int be_resolve_server_recv(struct tevent_req *req, struct fo_server **srv)
{
    struct be_resolve_server_state *state = tevent_req_data(req,
                                             struct be_resolve_server_state);

    TEVENT_REQ_RETURN_ON_ERROR(req);

    if (srv) {
        *srv = state->srv;
    }

    return EOK;
}