1 
2 /*
3  * Copyright (C) Ruslan Ermilov
4  * Copyright (C) Nginx, Inc.
5  */
6 
7 
8 #include <ngx_config.h>
9 #include <ngx_core.h>
10 #include <ngx_http.h>
11 
12 
13 static char *ngx_http_upstream_zone(ngx_conf_t *cf, ngx_command_t *cmd,
14     void *conf);
15 static ngx_int_t ngx_http_upstream_init_zone(ngx_shm_zone_t *shm_zone,
16     void *data);
17 static ngx_http_upstream_rr_peers_t *ngx_http_upstream_zone_copy_peers(
18     ngx_slab_pool_t *shpool, ngx_http_upstream_srv_conf_t *uscf);
19 static ngx_http_upstream_rr_peer_t *ngx_http_upstream_zone_copy_peer(
20     ngx_http_upstream_rr_peers_t *peers, ngx_http_upstream_rr_peer_t *src);
21 
22 
23 static ngx_command_t  ngx_http_upstream_zone_commands[] = {
24 
25     { ngx_string("zone"),
26       NGX_HTTP_UPS_CONF|NGX_CONF_TAKE12,
27       ngx_http_upstream_zone,
28       0,
29       0,
30       NULL },
31 
32       ngx_null_command
33 };
34 
35 
36 static ngx_http_module_t  ngx_http_upstream_zone_module_ctx = {
37     NULL,                                  /* preconfiguration */
38     NULL,                                  /* postconfiguration */
39 
40     NULL,                                  /* create main configuration */
41     NULL,                                  /* init main configuration */
42 
43     NULL,                                  /* create server configuration */
44     NULL,                                  /* merge server configuration */
45 
46     NULL,                                  /* create location configuration */
47     NULL                                   /* merge location configuration */
48 };
49 
50 
51 ngx_module_t  ngx_http_upstream_zone_module = {
52     NGX_MODULE_V1,
53     &ngx_http_upstream_zone_module_ctx,    /* module context */
54     ngx_http_upstream_zone_commands,       /* module directives */
55     NGX_HTTP_MODULE,                       /* module type */
56     NULL,                                  /* init master */
57     NULL,                                  /* init module */
58     NULL,                                  /* init process */
59     NULL,                                  /* init thread */
60     NULL,                                  /* exit thread */
61     NULL,                                  /* exit process */
62     NULL,                                  /* exit master */
63     NGX_MODULE_V1_PADDING
64 };
65 
66 
67 static char *
ngx_http_upstream_zone(ngx_conf_t * cf,ngx_command_t * cmd,void * conf)68 ngx_http_upstream_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
69 {
70     ssize_t                         size;
71     ngx_str_t                      *value;
72     ngx_http_upstream_srv_conf_t   *uscf;
73     ngx_http_upstream_main_conf_t  *umcf;
74 
75     uscf = ngx_http_conf_get_module_srv_conf(cf, ngx_http_upstream_module);
76     umcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_upstream_module);
77 
78     value = cf->args->elts;
79 
80     if (!value[1].len) {
81         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
82                            "invalid zone name \"%V\"", &value[1]);
83         return NGX_CONF_ERROR;
84     }
85 
86     if (cf->args->nelts == 3) {
87         size = ngx_parse_size(&value[2]);
88 
89         if (size == NGX_ERROR) {
90             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
91                                "invalid zone size \"%V\"", &value[2]);
92             return NGX_CONF_ERROR;
93         }
94 
95         if (size < (ssize_t) (8 * ngx_pagesize)) {
96             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
97                                "zone \"%V\" is too small", &value[1]);
98             return NGX_CONF_ERROR;
99         }
100 
101     } else {
102         size = 0;
103     }
104 
105     uscf->shm_zone = ngx_shared_memory_add(cf, &value[1], size,
106                                            &ngx_http_upstream_module);
107     if (uscf->shm_zone == NULL) {
108         return NGX_CONF_ERROR;
109     }
110 
111     uscf->shm_zone->init = ngx_http_upstream_init_zone;
112     uscf->shm_zone->data = umcf;
113 
114     uscf->shm_zone->noreuse = 1;
115 
116     return NGX_CONF_OK;
117 }
118 
119 
120 static ngx_int_t
ngx_http_upstream_init_zone(ngx_shm_zone_t * shm_zone,void * data)121 ngx_http_upstream_init_zone(ngx_shm_zone_t *shm_zone, void *data)
122 {
123     size_t                          len;
124     ngx_uint_t                      i;
125     ngx_slab_pool_t                *shpool;
126     ngx_http_upstream_rr_peers_t   *peers, **peersp;
127     ngx_http_upstream_srv_conf_t   *uscf, **uscfp;
128     ngx_http_upstream_main_conf_t  *umcf;
129 
130     shpool = (ngx_slab_pool_t *) shm_zone->shm.addr;
131     umcf = shm_zone->data;
132     uscfp = umcf->upstreams.elts;
133 
134     if (shm_zone->shm.exists) {
135         peers = shpool->data;
136 
137         for (i = 0; i < umcf->upstreams.nelts; i++) {
138             uscf = uscfp[i];
139 
140             if (uscf->shm_zone != shm_zone) {
141                 continue;
142             }
143 
144             uscf->peer.data = peers;
145             peers = peers->zone_next;
146         }
147 
148         return NGX_OK;
149     }
150 
151     len = sizeof(" in upstream zone \"\"") + shm_zone->shm.name.len;
152 
153     shpool->log_ctx = ngx_slab_alloc(shpool, len);
154     if (shpool->log_ctx == NULL) {
155         return NGX_ERROR;
156     }
157 
158     ngx_sprintf(shpool->log_ctx, " in upstream zone \"%V\"%Z",
159                 &shm_zone->shm.name);
160 
161 
162     /* copy peers to shared memory */
163 
164     peersp = (ngx_http_upstream_rr_peers_t **) (void *) &shpool->data;
165 
166     for (i = 0; i < umcf->upstreams.nelts; i++) {
167         uscf = uscfp[i];
168 
169         if (uscf->shm_zone != shm_zone) {
170             continue;
171         }
172 
173         peers = ngx_http_upstream_zone_copy_peers(shpool, uscf);
174         if (peers == NULL) {
175             return NGX_ERROR;
176         }
177 
178         *peersp = peers;
179         peersp = &peers->zone_next;
180     }
181 
182     return NGX_OK;
183 }
184 
185 
186 static ngx_http_upstream_rr_peers_t *
ngx_http_upstream_zone_copy_peers(ngx_slab_pool_t * shpool,ngx_http_upstream_srv_conf_t * uscf)187 ngx_http_upstream_zone_copy_peers(ngx_slab_pool_t *shpool,
188     ngx_http_upstream_srv_conf_t *uscf)
189 {
190     ngx_str_t                     *name;
191     ngx_http_upstream_rr_peer_t   *peer, **peerp;
192     ngx_http_upstream_rr_peers_t  *peers, *backup;
193 
194     peers = ngx_slab_alloc(shpool, sizeof(ngx_http_upstream_rr_peers_t));
195     if (peers == NULL) {
196         return NULL;
197     }
198 
199     ngx_memcpy(peers, uscf->peer.data, sizeof(ngx_http_upstream_rr_peers_t));
200 
201     name = ngx_slab_alloc(shpool, sizeof(ngx_str_t));
202     if (name == NULL) {
203         return NULL;
204     }
205 
206     name->data = ngx_slab_alloc(shpool, peers->name->len);
207     if (name->data == NULL) {
208         return NULL;
209     }
210 
211     ngx_memcpy(name->data, peers->name->data, peers->name->len);
212     name->len = peers->name->len;
213 
214     peers->name = name;
215 
216     peers->shpool = shpool;
217 
218     for (peerp = &peers->peer; *peerp; peerp = &peer->next) {
219         /* pool is unlocked */
220         peer = ngx_http_upstream_zone_copy_peer(peers, *peerp);
221         if (peer == NULL) {
222             return NULL;
223         }
224 
225         *peerp = peer;
226     }
227 
228     if (peers->next == NULL) {
229         goto done;
230     }
231 
232     backup = ngx_slab_alloc(shpool, sizeof(ngx_http_upstream_rr_peers_t));
233     if (backup == NULL) {
234         return NULL;
235     }
236 
237     ngx_memcpy(backup, peers->next, sizeof(ngx_http_upstream_rr_peers_t));
238 
239     backup->name = name;
240 
241     backup->shpool = shpool;
242 
243     for (peerp = &backup->peer; *peerp; peerp = &peer->next) {
244         /* pool is unlocked */
245         peer = ngx_http_upstream_zone_copy_peer(backup, *peerp);
246         if (peer == NULL) {
247             return NULL;
248         }
249 
250         *peerp = peer;
251     }
252 
253     peers->next = backup;
254 
255 done:
256 
257     uscf->peer.data = peers;
258 
259     return peers;
260 }
261 
262 
263 static ngx_http_upstream_rr_peer_t *
ngx_http_upstream_zone_copy_peer(ngx_http_upstream_rr_peers_t * peers,ngx_http_upstream_rr_peer_t * src)264 ngx_http_upstream_zone_copy_peer(ngx_http_upstream_rr_peers_t *peers,
265     ngx_http_upstream_rr_peer_t *src)
266 {
267     ngx_slab_pool_t              *pool;
268     ngx_http_upstream_rr_peer_t  *dst;
269 
270     pool = peers->shpool;
271 
272     dst = ngx_slab_calloc_locked(pool, sizeof(ngx_http_upstream_rr_peer_t));
273     if (dst == NULL) {
274         return NULL;
275     }
276 
277     if (src) {
278         ngx_memcpy(dst, src, sizeof(ngx_http_upstream_rr_peer_t));
279         dst->sockaddr = NULL;
280         dst->name.data = NULL;
281         dst->server.data = NULL;
282     }
283 
284     dst->sockaddr = ngx_slab_calloc_locked(pool, sizeof(ngx_sockaddr_t));
285     if (dst->sockaddr == NULL) {
286         goto failed;
287     }
288 
289     dst->name.data = ngx_slab_calloc_locked(pool, NGX_SOCKADDR_STRLEN);
290     if (dst->name.data == NULL) {
291         goto failed;
292     }
293 
294     if (src) {
295         ngx_memcpy(dst->sockaddr, src->sockaddr, src->socklen);
296         ngx_memcpy(dst->name.data, src->name.data, src->name.len);
297 
298         dst->server.data = ngx_slab_alloc_locked(pool, src->server.len);
299         if (dst->server.data == NULL) {
300             goto failed;
301         }
302 
303         ngx_memcpy(dst->server.data, src->server.data, src->server.len);
304     }
305 
306     return dst;
307 
308 failed:
309 
310     if (dst->server.data) {
311         ngx_slab_free_locked(pool, dst->server.data);
312     }
313 
314     if (dst->name.data) {
315         ngx_slab_free_locked(pool, dst->name.data);
316     }
317 
318     if (dst->sockaddr) {
319         ngx_slab_free_locked(pool, dst->sockaddr);
320     }
321 
322     ngx_slab_free_locked(pool, dst);
323 
324     return NULL;
325 }
326