xref: /lighttpd1.4/src/mod_vhostdb.c (revision 8f84c7be)
1 /*
2  * mod_vhostdb - virtual hosts mapping from backend database
3  *
4  * Copyright(c) 2017 Glenn Strauss gstrauss()gluelogic.com  All rights reserved
5  * License: BSD 3-clause (same as lighttpd)
6  */
7 #include "first.h"
8 
9 #include <stdlib.h>
10 #include <string.h>
11 
12 #include "mod_vhostdb_api.h"
13 #include "base.h"
14 #include "plugin.h"
15 #include "plugin_config.h"
16 #include "log.h"
17 #include "stat_cache.h"
18 #include "algo_splaytree.h"
19 
20 /**
21  * vhostdb framework
22  */
23 
24 typedef struct {
25     splay_tree *sptree; /* data in nodes of tree are (vhostdb_cache_entry *) */
26     time_t max_age;
27 } vhostdb_cache;
28 
29 typedef struct {
30     const http_vhostdb_backend_t *vhostdb_backend;
31     vhostdb_cache *vhostdb_cache;
32 } plugin_config;
33 
34 typedef struct {
35     PLUGIN_DATA;
36     plugin_config defaults;
37     plugin_config conf;
38 } plugin_data;
39 
40 typedef struct {
41     char *server_name;
42     char *document_root;
43     uint32_t slen;
44     uint32_t dlen;
45     unix_time64_t ctime;
46 } vhostdb_cache_entry;
47 
48 static vhostdb_cache_entry *
vhostdb_cache_entry_init(const buffer * const server_name,const buffer * const docroot)49 vhostdb_cache_entry_init (const buffer * const server_name, const buffer * const docroot)
50 {
51     const uint32_t slen = buffer_clen(server_name);
52     const uint32_t dlen = buffer_clen(docroot);
53     vhostdb_cache_entry * const ve =
54       ck_malloc(sizeof(vhostdb_cache_entry) + slen + dlen);
55     ve->ctime = log_monotonic_secs;
56     ve->slen = slen;
57     ve->dlen = dlen;
58     ve->server_name   = (char *)(ve + 1);
59     ve->document_root = ve->server_name + slen;
60     memcpy(ve->server_name,   server_name->ptr, slen);
61     memcpy(ve->document_root, docroot->ptr,     dlen);
62     return ve;
63 }
64 
65 static void
vhostdb_cache_entry_free(vhostdb_cache_entry * ve)66 vhostdb_cache_entry_free (vhostdb_cache_entry *ve)
67 {
68     free(ve);
69 }
70 
71 static void
vhostdb_cache_free(vhostdb_cache * vc)72 vhostdb_cache_free (vhostdb_cache *vc)
73 {
74     splay_tree *sptree = vc->sptree;
75     while (sptree) {
76         vhostdb_cache_entry_free(sptree->data);
77         sptree = splaytree_delete(sptree, sptree->key);
78     }
79     free(vc);
80 }
81 
82 static vhostdb_cache *
vhostdb_cache_init(const array * opts)83 vhostdb_cache_init (const array *opts)
84 {
85     vhostdb_cache *vc = ck_malloc(sizeof(vhostdb_cache));
86     vc->sptree = NULL;
87     vc->max_age = 600; /* 10 mins */
88     for (uint32_t i = 0, used = opts->used; i < used; ++i) {
89         data_unset *du = opts->data[i];
90         if (buffer_is_equal_string(&du->key, CONST_STR_LEN("max-age")))
91             vc->max_age = (time_t)
92               config_plugin_value_to_int32(du, 600); /* 10 min if invalid num */
93     }
94     return vc;
95 }
96 
97 static vhostdb_cache_entry *
mod_vhostdb_cache_query(request_st * const r,plugin_data * const p)98 mod_vhostdb_cache_query (request_st * const r, plugin_data * const p)
99 {
100     const int ndx = splaytree_djbhash(BUF_PTR_LEN(&r->uri.authority));
101     splay_tree ** const sptree = &p->conf.vhostdb_cache->sptree;
102     *sptree = splaytree_splay(*sptree, ndx);
103     vhostdb_cache_entry * const ve =
104       (*sptree && (*sptree)->key == ndx) ? (*sptree)->data : NULL;
105 
106     return ve
107         && buffer_is_equal_string(&r->uri.authority, ve->server_name, ve->slen)
108       ? ve
109       : NULL;
110 }
111 
112 static void
mod_vhostdb_cache_insert(request_st * const r,plugin_data * const p,vhostdb_cache_entry * const ve)113 mod_vhostdb_cache_insert (request_st * const r, plugin_data * const p, vhostdb_cache_entry * const ve)
114 {
115     const int ndx = splaytree_djbhash(BUF_PTR_LEN(&r->uri.authority));
116     splay_tree ** const sptree = &p->conf.vhostdb_cache->sptree;
117     /*(not necessary to re-splay (with current usage) since single-threaded
118      * and splaytree has not been modified since mod_vhostdb_cache_query())*/
119     /* *sptree = splaytree_splay(*sptree, ndx); */
120     if (NULL == *sptree || (*sptree)->key != ndx)
121         *sptree = splaytree_insert(*sptree, ndx, ve);
122     else { /* collision; replace old entry */
123         vhostdb_cache_entry_free((*sptree)->data);
124         (*sptree)->data = ve;
125     }
126 }
127 
INIT_FUNC(mod_vhostdb_init)128 INIT_FUNC(mod_vhostdb_init) {
129     return ck_calloc(1, sizeof(plugin_data));
130 }
131 
FREE_FUNC(mod_vhostdb_free)132 FREE_FUNC(mod_vhostdb_free) {
133     plugin_data *p = p_d;
134 
135     if (NULL == p->cvlist) return;
136     /* (init i to 0 if global context; to 1 to skip empty global context) */
137     for (int i = !p->cvlist[0].v.u2[1], used = p->nconfig; i < used; ++i) {
138         config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
139         for (; -1 != cpv->k_id; ++cpv) {
140             if (cpv->vtype != T_CONFIG_LOCAL || NULL == cpv->v.v) continue;
141             switch (cpv->k_id) {
142               case 1: /* vhostdb.cache */
143                 vhostdb_cache_free(cpv->v.v);
144                 break;
145               default:
146                 break;
147             }
148         }
149     }
150 
151     http_vhostdb_dumbdata_reset();
152 }
153 
mod_vhostdb_merge_config_cpv(plugin_config * const pconf,const config_plugin_value_t * const cpv)154 static void mod_vhostdb_merge_config_cpv(plugin_config * const pconf, const config_plugin_value_t * const cpv) {
155     switch (cpv->k_id) { /* index into static config_plugin_keys_t cpk[] */
156       case 0: /* vhostdb.backend */
157         if (cpv->vtype == T_CONFIG_LOCAL)
158             pconf->vhostdb_backend = cpv->v.v;
159         break;
160       case 1: /* vhostdb.cache */
161         if (cpv->vtype == T_CONFIG_LOCAL)
162             pconf->vhostdb_cache = cpv->v.v;
163         break;
164       default:/* should not happen */
165         return;
166     }
167 }
168 
mod_vhostdb_merge_config(plugin_config * const pconf,const config_plugin_value_t * cpv)169 static void mod_vhostdb_merge_config(plugin_config * const pconf, const config_plugin_value_t *cpv) {
170     do {
171         mod_vhostdb_merge_config_cpv(pconf, cpv);
172     } while ((++cpv)->k_id != -1);
173 }
174 
mod_vhostdb_patch_config(request_st * const r,plugin_data * const p)175 static void mod_vhostdb_patch_config(request_st * const r, plugin_data * const p) {
176     memcpy(&p->conf, &p->defaults, sizeof(plugin_config));
177     for (int i = 1, used = p->nconfig; i < used; ++i) {
178         if (config_check_cond(r, (uint32_t)p->cvlist[i].k_id))
179             mod_vhostdb_merge_config(&p->conf, p->cvlist + p->cvlist[i].v.u2[0]);
180     }
181 }
182 
SETDEFAULTS_FUNC(mod_vhostdb_set_defaults)183 SETDEFAULTS_FUNC(mod_vhostdb_set_defaults) {
184     static const config_plugin_keys_t cpk[] = {
185       { CONST_STR_LEN("vhostdb.backend"),
186         T_CONFIG_STRING,
187         T_CONFIG_SCOPE_CONNECTION }
188      ,{ CONST_STR_LEN("vhostdb.cache"),
189         T_CONFIG_ARRAY,
190         T_CONFIG_SCOPE_CONNECTION }
191      ,{ NULL, 0,
192         T_CONFIG_UNSET,
193         T_CONFIG_SCOPE_UNSET }
194     };
195 
196     plugin_data * const p = p_d;
197     if (!config_plugin_values_init(srv, p, cpk, "mod_vhostdb"))
198         return HANDLER_ERROR;
199 
200     /* process and validate config directives
201      * (init i to 0 if global context; to 1 to skip empty global context) */
202     for (int i = !p->cvlist[0].v.u2[1]; i < p->nconfig; ++i) {
203         config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
204         for (; -1 != cpv->k_id; ++cpv) {
205             switch (cpv->k_id) {
206               case 0: /* vhostdb.backend */
207                 if (!buffer_is_blank(cpv->v.b)) {
208                     const buffer * const b = cpv->v.b;
209                     *(const void **)&cpv->v.v = http_vhostdb_backend_get(b);
210                     if (NULL == cpv->v.v) {
211                         log_error(srv->errh, __FILE__, __LINE__,
212                           "vhostdb.backend not supported: %s", b->ptr);
213                         return HANDLER_ERROR;
214                     }
215                     cpv->vtype = T_CONFIG_LOCAL;
216                 }
217                 break;
218               case 1: /* vhostdb.cache */
219                 cpv->v.v = vhostdb_cache_init(cpv->v.a);
220                 cpv->vtype = T_CONFIG_LOCAL;
221                 break;
222               default:/* should not happen */
223                 break;
224             }
225         }
226     }
227 
228     /* initialize p->defaults from global config context */
229     if (p->nconfig > 0 && p->cvlist->v.u2[1]) {
230         const config_plugin_value_t *cpv = p->cvlist + p->cvlist->v.u2[0];
231         if (-1 != cpv->k_id)
232             mod_vhostdb_merge_config(&p->defaults, cpv);
233     }
234 
235     return HANDLER_GO_ON;
236 }
237 
REQUEST_FUNC(mod_vhostdb_handle_request_reset)238 REQUEST_FUNC(mod_vhostdb_handle_request_reset) {
239     plugin_data *p = p_d;
240     vhostdb_cache_entry *ve;
241 
242     if ((ve = r->plugin_ctx[p->id])) {
243         r->plugin_ctx[p->id] = NULL;
244         vhostdb_cache_entry_free(ve);
245     }
246 
247     return HANDLER_GO_ON;
248 }
249 
250 __attribute_cold__
mod_vhostdb_error_500(request_st * const r)251 static handler_t mod_vhostdb_error_500 (request_st * const r)
252 {
253     r->http_status = 500; /* Internal Server Error */
254     r->handler_module = NULL;
255     return HANDLER_FINISHED;
256 }
257 
mod_vhostdb_found(request_st * const r,vhostdb_cache_entry * const ve)258 static handler_t mod_vhostdb_found (request_st * const r, vhostdb_cache_entry * const ve)
259 {
260     /* fix virtual server and docroot */
261     if (ve->slen) {
262         r->server_name = &r->server_name_buf;
263         buffer_copy_string_len(&r->server_name_buf, ve->server_name, ve->slen);
264     }
265     buffer_copy_string_len(&r->physical.doc_root, ve->document_root, ve->dlen);
266     return HANDLER_GO_ON;
267 }
268 
REQUEST_FUNC(mod_vhostdb_handle_docroot)269 REQUEST_FUNC(mod_vhostdb_handle_docroot) {
270     plugin_data *p = p_d;
271     vhostdb_cache_entry *ve;
272 
273     /* no host specified? */
274     if (buffer_is_blank(&r->uri.authority)) return HANDLER_GO_ON;
275 
276     /* check if cached this connection */
277     ve = r->plugin_ctx[p->id];
278     if (ve
279         && buffer_is_equal_string(&r->uri.authority, ve->server_name, ve->slen))
280         return mod_vhostdb_found(r, ve); /* HANDLER_GO_ON */
281 
282     mod_vhostdb_patch_config(r, p);
283     if (!p->conf.vhostdb_backend) return HANDLER_GO_ON;
284 
285     if (p->conf.vhostdb_cache && (ve = mod_vhostdb_cache_query(r, p)))
286         return mod_vhostdb_found(r, ve); /* HANDLER_GO_ON */
287 
288     buffer * const b = r->tmp_buf; /*(cleared before use in backend->query())*/
289     const http_vhostdb_backend_t * const backend = p->conf.vhostdb_backend;
290     if (0 != backend->query(r, backend->p_d, b)) {
291         return mod_vhostdb_error_500(r); /* HANDLER_FINISHED */
292     }
293 
294     if (buffer_is_blank(b)) {
295         /* no such virtual host */
296         return HANDLER_GO_ON;
297     }
298 
299     /* sanity check that really is a directory */
300     buffer_append_slash(b);
301     if (!stat_cache_path_isdir(b)) {
302         log_perror(r->conf.errh, __FILE__, __LINE__, "%s", b->ptr);
303         return mod_vhostdb_error_500(r); /* HANDLER_FINISHED */
304     }
305 
306     if (ve && !p->conf.vhostdb_cache)
307         vhostdb_cache_entry_free(ve);
308 
309     ve = vhostdb_cache_entry_init(&r->uri.authority, b);
310 
311     if (!p->conf.vhostdb_cache)
312         r->plugin_ctx[p->id] = ve;
313     else
314         mod_vhostdb_cache_insert(r, p, ve);
315 
316     return mod_vhostdb_found(r, ve); /* HANDLER_GO_ON */
317 }
318 
319 /* walk though cache, collect expired ids, and remove them in a second loop */
320 static void
mod_vhostdb_tag_old_entries(splay_tree * const t,int * const keys,int * const ndx,const time_t max_age,const unix_time64_t cur_ts)321 mod_vhostdb_tag_old_entries (splay_tree * const t, int * const keys, int * const ndx, const time_t max_age, const unix_time64_t cur_ts)
322 {
323     if (*ndx == 8192) return; /*(must match num array entries in keys[])*/
324     if (t->left)
325         mod_vhostdb_tag_old_entries(t->left, keys, ndx, max_age, cur_ts);
326     if (t->right)
327         mod_vhostdb_tag_old_entries(t->right, keys, ndx, max_age, cur_ts);
328     if (*ndx == 8192) return; /*(must match num array entries in keys[])*/
329 
330     const vhostdb_cache_entry * const ve = t->data;
331     if (cur_ts - ve->ctime > max_age)
332         keys[(*ndx)++] = t->key;
333 }
334 
335 __attribute_noinline__
336 static void
mod_vhostdb_periodic_cleanup(splay_tree ** sptree_ptr,const time_t max_age,const unix_time64_t cur_ts)337 mod_vhostdb_periodic_cleanup(splay_tree **sptree_ptr, const time_t max_age, const unix_time64_t cur_ts)
338 {
339     splay_tree *sptree = *sptree_ptr;
340     int max_ndx, i;
341     int keys[8192]; /* 32k size on stack */
342     do {
343         if (!sptree) break;
344         max_ndx = 0;
345         mod_vhostdb_tag_old_entries(sptree, keys, &max_ndx, max_age, cur_ts);
346         for (i = 0; i < max_ndx; ++i) {
347             int ndx = keys[i];
348             sptree = splaytree_splay(sptree, ndx);
349             if (sptree && sptree->key == ndx) {
350                 vhostdb_cache_entry_free(sptree->data);
351                 sptree = splaytree_delete(sptree, ndx);
352             }
353         }
354     } while (max_ndx == sizeof(keys)/sizeof(int));
355     *sptree_ptr = sptree;
356 }
357 
TRIGGER_FUNC(mod_vhostdb_periodic)358 TRIGGER_FUNC(mod_vhostdb_periodic)
359 {
360     const plugin_data * const p = p_d;
361     const unix_time64_t cur_ts = log_monotonic_secs;
362     if (cur_ts & 0x7) return HANDLER_GO_ON; /*(continue once each 8 sec)*/
363     UNUSED(srv);
364 
365     /* future: might construct array of (vhostdb_cache *) at startup
366      *         to avoid the need to search for them here */
367     /* (init i to 0 if global context; to 1 to skip empty global context) */
368     if (NULL == p->cvlist) return HANDLER_GO_ON;
369     for (int i = !p->cvlist[0].v.u2[1], used = p->nconfig; i < used; ++i) {
370         const config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
371         for (; cpv->k_id != -1; ++cpv) {
372             if (cpv->k_id != 1) continue; /* k_id == 1 for vhostdb.cache */
373             if (cpv->vtype != T_CONFIG_LOCAL) continue;
374             vhostdb_cache *vc = cpv->v.v;
375             mod_vhostdb_periodic_cleanup(&vc->sptree, vc->max_age, cur_ts);
376         }
377     }
378 
379     return HANDLER_GO_ON;
380 }
381 
382 
383 __attribute_cold__
384 int mod_vhostdb_plugin_init(plugin *p);
mod_vhostdb_plugin_init(plugin * p)385 int mod_vhostdb_plugin_init(plugin *p) {
386     p->version          = LIGHTTPD_VERSION_ID;
387     p->name             = "vhostdb";
388     p->init             = mod_vhostdb_init;
389     p->cleanup          = mod_vhostdb_free;
390     p->set_defaults     = mod_vhostdb_set_defaults;
391     p->handle_trigger   = mod_vhostdb_periodic;
392     p->handle_docroot   = mod_vhostdb_handle_docroot;
393     p->handle_request_reset = mod_vhostdb_handle_request_reset;
394 
395     return 0;
396 }
397