xref: /lighttpd1.4/src/mod_scgi.c (revision e11f72b1)
1 #include "first.h"
2 
3 #include <sys/types.h>
4 #include <limits.h>
5 #include <stdlib.h>
6 #include <string.h>
7 
8 #include "gw_backend.h"
9 typedef gw_plugin_config plugin_config;
10 typedef gw_plugin_data   plugin_data;
11 typedef gw_handler_ctx   handler_ctx;
12 
13 #include "base.h"
14 #include "buffer.h"
15 #include "log.h"
16 #include "status_counter.h"
17 
18 #include "sys-endian.h"
19 
20 enum { LI_PROTOCOL_SCGI, LI_PROTOCOL_UWSGI };
21 
22 static void mod_scgi_merge_config_cpv(plugin_config * const pconf, const config_plugin_value_t * const cpv) {
23     switch (cpv->k_id) { /* index into static config_plugin_keys_t cpk[] */
24       case 0: /* scgi.server */
25         if (cpv->vtype == T_CONFIG_LOCAL) {
26             gw_plugin_config * const gw = cpv->v.v;
27             pconf->exts      = gw->exts;
28             pconf->exts_auth = gw->exts_auth;
29             pconf->exts_resp = gw->exts_resp;
30         }
31         break;
32       case 1: /* scgi.balance */
33         /*if (cpv->vtype == T_CONFIG_LOCAL)*//*always true here for this param*/
34             pconf->balance = (int)cpv->v.u;
35         break;
36       case 2: /* scgi.debug */
37         pconf->debug = (int)cpv->v.u;
38         break;
39       case 3: /* scgi.map-extensions */
40         pconf->ext_mapping = cpv->v.a;
41         break;
42       case 4: /* scgi.protocol */
43         /*if (cpv->vtype == T_CONFIG_LOCAL)*//*always true here for this param*/
44             pconf->proto = (int)cpv->v.u;
45         break;
46       default:/* should not happen */
47         return;
48     }
49 }
50 
51 static void mod_scgi_merge_config(plugin_config * const pconf, const config_plugin_value_t *cpv) {
52     do {
53         mod_scgi_merge_config_cpv(pconf, cpv);
54     } while ((++cpv)->k_id != -1);
55 }
56 
57 static void mod_scgi_patch_config(request_st * const r, plugin_data * const p) {
58     memcpy(&p->conf, &p->defaults, sizeof(plugin_config));
59     for (int i = 1, used = p->nconfig; i < used; ++i) {
60         if (config_check_cond(r, (uint32_t)p->cvlist[i].k_id))
61             mod_scgi_merge_config(&p->conf, p->cvlist + p->cvlist[i].v.u2[0]);
62     }
63 }
64 
65 SETDEFAULTS_FUNC(mod_scgi_set_defaults) {
66     static const config_plugin_keys_t cpk[] = {
67       { CONST_STR_LEN("scgi.server"),
68         T_CONFIG_ARRAY_KVARRAY,
69         T_CONFIG_SCOPE_CONNECTION }
70      ,{ CONST_STR_LEN("scgi.balance"),
71         T_CONFIG_STRING,
72         T_CONFIG_SCOPE_CONNECTION }
73      ,{ CONST_STR_LEN("scgi.debug"),
74         T_CONFIG_INT,
75         T_CONFIG_SCOPE_CONNECTION }
76      ,{ CONST_STR_LEN("scgi.map-extensions"),
77         T_CONFIG_ARRAY_KVSTRING,
78         T_CONFIG_SCOPE_CONNECTION }
79      ,{ CONST_STR_LEN("scgi.protocol"),
80         T_CONFIG_STRING,
81         T_CONFIG_SCOPE_CONNECTION }
82      ,{ NULL, 0,
83         T_CONFIG_UNSET,
84         T_CONFIG_SCOPE_UNSET }
85     };
86 
87     plugin_data * const p = p_d;
88     if (!config_plugin_values_init(srv, p, cpk, "mod_scgi"))
89         return HANDLER_ERROR;
90 
91     /* process and validate config directives
92      * (init i to 0 if global context; to 1 to skip empty global context) */
93     for (int i = !p->cvlist[0].v.u2[1]; i < p->nconfig; ++i) {
94         config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
95         for (; -1 != cpv->k_id; ++cpv) {
96             switch (cpv->k_id) {
97               case 0:{/* scgi.server */
98                 gw_plugin_config *gw = calloc(1, sizeof(gw_plugin_config));
99                 force_assert(gw);
100                 if (!gw_set_defaults_backend(srv, p, cpv->v.a, gw, 1,
101                                              cpk[cpv->k_id].k)) {
102                     gw_plugin_config_free(gw);
103                     return HANDLER_ERROR;
104                 }
105                 cpv->v.v = gw;
106                 cpv->vtype = T_CONFIG_LOCAL;
107                 break;
108               }
109               case 1: /* scgi.balance */
110                 cpv->v.u = (unsigned int)gw_get_defaults_balance(srv, cpv->v.b);
111                 break;
112               case 2: /* scgi.debug */
113               case 3: /* scgi.map-extensions */
114                 break;
115               case 4: /* scgi.protocol */
116                 if (buffer_eq_slen(cpv->v.b, CONST_STR_LEN("scgi")))
117                     cpv->v.u = LI_PROTOCOL_SCGI;
118                 else if (buffer_eq_slen(cpv->v.b, CONST_STR_LEN("uwsgi")))
119                     cpv->v.u = LI_PROTOCOL_UWSGI;
120                 else {
121                     log_error(srv->errh, __FILE__, __LINE__,
122                       "unexpected type for key: %s"
123                       "expected \"scgi\" or \"uwsgi\"", cpk[cpv->k_id].k);
124                     return HANDLER_ERROR;
125                 }
126                 break;
127               default:/* should not happen */
128                 break;
129             }
130         }
131     }
132 
133     /* default is 0 */
134     /*p->defaults.balance = (unsigned int)gw_get_defaults_balance(srv, NULL);*/
135     /*p->defaults.proto   = LI_PROTOCOL_SCGI;*//*(default)*/
136 
137     /* initialize p->defaults from global config context */
138     if (p->nconfig > 0 && p->cvlist->v.u2[1]) {
139         const config_plugin_value_t *cpv = p->cvlist + p->cvlist->v.u2[0];
140         if (-1 != cpv->k_id)
141             mod_scgi_merge_config(&p->defaults, cpv);
142     }
143 
144     return HANDLER_GO_ON;
145 }
146 
147 static int scgi_env_add_scgi(void *venv, const char *key, size_t key_len, const char *val, size_t val_len) {
148 	buffer *env = venv;
149 	char *dst;
150 	size_t len;
151 
152 	if (!key || !val) return -1;
153 
154 	len = key_len + val_len + 2;
155 
156 	if (buffer_string_space(env) < len) {
157 		size_t extend = env->size * 2 - buffer_string_length(env);
158 		extend = extend > len ? extend : len + 4095;
159 		buffer_string_prepare_append(env, extend);
160 	}
161 
162 	dst = buffer_string_prepare_append(env, len);
163 	memcpy(dst, key, key_len);
164 	dst[key_len] = '\0';
165 	memcpy(dst + key_len + 1, val, val_len);
166 	dst[key_len + 1 + val_len] = '\0';
167 	buffer_commit(env, len);
168 
169 	return 0;
170 }
171 
172 
173 #ifdef __LITTLE_ENDIAN__
174 #define uwsgi_htole16(x) (x)
175 #else /* __BIG_ENDIAN__ */
176 #define uwsgi_htole16(x) ((uint16_t) (((x) & 0xff) << 8 | ((x) & 0xff00) >> 8))
177 #endif
178 
179 
180 static int scgi_env_add_uwsgi(void *venv, const char *key, size_t key_len, const char *val, size_t val_len) {
181 	buffer *env = venv;
182 	char *dst;
183 	size_t len;
184 	uint16_t uwlen;
185 
186 	if (!key || !val) return -1;
187 	if (key_len > USHRT_MAX || val_len > USHRT_MAX) return -1;
188 
189 	len = 2 + key_len + 2 + val_len;
190 
191 	if (buffer_string_space(env) < len) {
192 		size_t extend = env->size * 2 - buffer_string_length(env);
193 		extend = extend > len ? extend : len + 4095;
194 		buffer_string_prepare_append(env, extend);
195 	}
196 
197 	dst = buffer_string_prepare_append(env, len);
198 	uwlen = uwsgi_htole16((uint16_t)key_len);
199 	memcpy(dst, (char *)&uwlen, 2);
200 	memcpy(dst + 2, key, key_len);
201 	uwlen = uwsgi_htole16((uint16_t)val_len);
202 	memcpy(dst + 2 + key_len, (char *)&uwlen, 2);
203 	memcpy(dst + 2 + key_len + 2, val, val_len);
204 	buffer_commit(env, len);
205 
206 	return 0;
207 }
208 
209 
210 static handler_t scgi_create_env(handler_ctx *hctx) {
211 	gw_host *host = hctx->host;
212 	request_st * const r = hctx->r;
213 	http_cgi_opts opts = { 0, 0, host->docroot, NULL };
214 	http_cgi_header_append_cb scgi_env_add = hctx->conf.proto == LI_PROTOCOL_SCGI
215 	  ? scgi_env_add_scgi
216 	  : scgi_env_add_uwsgi;
217 	size_t offset;
218 	size_t rsz = (size_t)(r->read_queue->bytes_out - hctx->wb->bytes_in);
219 	buffer * const b = chunkqueue_prepend_buffer_open_sz(hctx->wb, rsz < 65536 ? rsz : r->rqst_header_len);
220 
221         /* save space for 9 digits (plus ':'), though incoming HTTP request
222 	 * currently limited to 64k (65535, so 5 chars) */
223 	buffer_copy_string_len(b, CONST_STR_LEN("          "));
224 
225 	if (0 != http_cgi_headers(r, &opts, scgi_env_add, b)) {
226 		r->http_status = 400;
227 		r->handler_module = NULL;
228 		buffer_clear(b);
229 		chunkqueue_remove_finished_chunks(hctx->wb);
230 		return HANDLER_FINISHED;
231 	}
232 
233 	if (hctx->conf.proto == LI_PROTOCOL_SCGI) {
234 		buffer * const tb = r->tmp_buf;
235 		size_t len;
236 		scgi_env_add(b, CONST_STR_LEN("SCGI"), CONST_STR_LEN("1"));
237 		buffer_clear(tb);
238 		buffer_append_int(tb, buffer_string_length(b)-10);
239 		buffer_append_string_len(tb, CONST_STR_LEN(":"));
240 		len = buffer_string_length(tb);
241 		offset = 10 - len;
242 		memcpy(b->ptr+offset, tb->ptr, len);
243 		buffer_append_string_len(b, CONST_STR_LEN(","));
244 	} else { /* LI_PROTOCOL_UWSGI */
245 		/* http://uwsgi-docs.readthedocs.io/en/latest/Protocol.html */
246 		size_t len = buffer_string_length(b)-10;
247 		uint32_t uwsgi_header;
248 		if (len > USHRT_MAX) {
249 			r->http_status = 431; /* Request Header Fields Too Large */
250 			r->handler_module = NULL;
251 			buffer_clear(b);
252 			chunkqueue_remove_finished_chunks(hctx->wb);
253 			return HANDLER_FINISHED;
254 		}
255 		offset = 10 - 4;
256 		uwsgi_header = ((uint32_t)uwsgi_htole16((uint16_t)len)) << 8;
257 		memcpy(b->ptr+offset, (char *)&uwsgi_header, 4);
258 	}
259 
260 	hctx->wb_reqlen = buffer_string_length(b) - offset;
261 	chunkqueue_prepend_buffer_commit(hctx->wb);
262       #if 0
263 	hctx->wb->first->offset += (off_t)offset;
264 	hctx->wb->bytes_in -= (off_t)offset;
265       #else
266 	chunkqueue_mark_written(hctx->wb, offset);
267       #endif
268 
269 	if (r->reqbody_length) {
270 		chunkqueue_append_chunkqueue(hctx->wb, r->reqbody_queue);
271 		if (r->reqbody_length > 0)
272 			hctx->wb_reqlen += r->reqbody_length; /* total req size */
273 		else /* as-yet-unknown total request size (Transfer-Encoding: chunked)*/
274 			hctx->wb_reqlen = -hctx->wb_reqlen;
275 	}
276 
277 	status_counter_inc(CONST_STR_LEN("scgi.requests"));
278 	return HANDLER_GO_ON;
279 }
280 
281 
282 static handler_t scgi_check_extension(request_st * const r, void *p_d, int uri_path_handler) {
283 	plugin_data *p = p_d;
284 	handler_t rc;
285 
286 	if (NULL != r->handler_module) return HANDLER_GO_ON;
287 
288 	mod_scgi_patch_config(r, p);
289 	if (NULL == p->conf.exts) return HANDLER_GO_ON;
290 
291 	rc = gw_check_extension(r, p, uri_path_handler, 0);
292 	if (HANDLER_GO_ON != rc) return rc;
293 
294 	if (r->handler_module == p->self) {
295 		handler_ctx *hctx = r->plugin_ctx[p->id];
296 		hctx->opts.backend = BACKEND_SCGI;
297 		hctx->create_env = scgi_create_env;
298 		hctx->response = chunk_buffer_acquire();
299 	}
300 
301 	return HANDLER_GO_ON;
302 }
303 
304 /* uri-path handler */
305 static handler_t scgi_check_extension_1(request_st * const r, void *p_d) {
306 	return scgi_check_extension(r, p_d, 1);
307 }
308 
309 /* start request handler */
310 static handler_t scgi_check_extension_2(request_st * const r, void *p_d) {
311 	return scgi_check_extension(r, p_d, 0);
312 }
313 
314 
315 
316 int mod_scgi_plugin_init(plugin *p);
317 int mod_scgi_plugin_init(plugin *p) {
318 	p->version     = LIGHTTPD_VERSION_ID;
319 	p->name         = "scgi";
320 
321 	p->init         = gw_init;
322 	p->cleanup      = gw_free;
323 	p->set_defaults = mod_scgi_set_defaults;
324 	p->connection_reset        = gw_connection_reset;
325 	p->handle_uri_clean        = scgi_check_extension_1;
326 	p->handle_subrequest_start = scgi_check_extension_2;
327 	p->handle_subrequest       = gw_handle_subrequest;
328 	p->handle_trigger          = gw_handle_trigger;
329 	p->handle_waitpid          = gw_handle_waitpid_cb;
330 
331 	return 0;
332 }
333