xref: /spdk/lib/jsonrpc/jsonrpc_server.c (revision b30d57cdad6d2bc75cc1e4e2ebbcebcb0d98dcfa)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "jsonrpc_internal.h"
35 
36 #include "spdk/util.h"
37 
38 struct jsonrpc_request {
39 	const struct spdk_json_val *version;
40 	const struct spdk_json_val *method;
41 	const struct spdk_json_val *params;
42 	const struct spdk_json_val *id;
43 };
44 
45 static int
46 capture_val(const struct spdk_json_val *val, void *out)
47 {
48 	const struct spdk_json_val **vptr = out;
49 
50 	*vptr = val;
51 	return 0;
52 }
53 
54 static const struct spdk_json_object_decoder jsonrpc_request_decoders[] = {
55 	{"jsonrpc", offsetof(struct jsonrpc_request, version), capture_val, true},
56 	{"method", offsetof(struct jsonrpc_request, method), capture_val},
57 	{"params", offsetof(struct jsonrpc_request, params), capture_val, true},
58 	{"id", offsetof(struct jsonrpc_request, id), capture_val, true},
59 };
60 
61 static void
62 parse_single_request(struct spdk_jsonrpc_request *request, struct spdk_json_val *values)
63 {
64 	struct jsonrpc_request req = {};
65 	const struct spdk_json_val *params = NULL;
66 
67 	if (spdk_json_decode_object(values, jsonrpc_request_decoders,
68 				    SPDK_COUNTOF(jsonrpc_request_decoders),
69 				    &req)) {
70 		goto invalid;
71 	}
72 
73 	if (req.version && (req.version->type != SPDK_JSON_VAL_STRING ||
74 			    !spdk_json_strequal(req.version, "2.0"))) {
75 		goto invalid;
76 	}
77 
78 	if (!req.method || req.method->type != SPDK_JSON_VAL_STRING) {
79 		goto invalid;
80 	}
81 
82 	if (req.id) {
83 		if (req.id->type == SPDK_JSON_VAL_STRING ||
84 		    req.id->type == SPDK_JSON_VAL_NUMBER ||
85 		    req.id->type == SPDK_JSON_VAL_NULL) {
86 			request->id = req.id;
87 		} else  {
88 			goto invalid;
89 		}
90 	}
91 
92 	if (req.params) {
93 		/* null json value is as if there were no parameters */
94 		if (req.params->type != SPDK_JSON_VAL_NULL) {
95 			if (req.params->type != SPDK_JSON_VAL_ARRAY_BEGIN &&
96 			    req.params->type != SPDK_JSON_VAL_OBJECT_BEGIN) {
97 				goto invalid;
98 			}
99 			params = req.params;
100 		}
101 	}
102 
103 	jsonrpc_server_handle_request(request, req.method, params);
104 	return;
105 
106 invalid:
107 	jsonrpc_server_handle_error(request, SPDK_JSONRPC_ERROR_INVALID_REQUEST);
108 }
109 
110 static int
111 jsonrpc_server_write_cb(void *cb_ctx, const void *data, size_t size)
112 {
113 	struct spdk_jsonrpc_request *request = cb_ctx;
114 	size_t new_size = request->send_buf_size;
115 
116 	while (new_size - request->send_len < size) {
117 		if (new_size >= SPDK_JSONRPC_SEND_BUF_SIZE_MAX) {
118 			SPDK_ERRLOG("Send buf exceeded maximum size (%zu)\n",
119 				    (size_t)SPDK_JSONRPC_SEND_BUF_SIZE_MAX);
120 			return -1;
121 		}
122 
123 		new_size *= 2;
124 	}
125 
126 	if (new_size != request->send_buf_size) {
127 		uint8_t *new_buf;
128 
129 		new_buf = realloc(request->send_buf, new_size);
130 		if (new_buf == NULL) {
131 			SPDK_ERRLOG("Resizing send_buf failed (current size %zu, new size %zu)\n",
132 				    request->send_buf_size, new_size);
133 			return -1;
134 		}
135 
136 		request->send_buf = new_buf;
137 		request->send_buf_size = new_size;
138 	}
139 
140 	memcpy(request->send_buf + request->send_len, data, size);
141 	request->send_len += size;
142 
143 	return 0;
144 }
145 
146 int
147 jsonrpc_parse_request(struct spdk_jsonrpc_server_conn *conn, const void *json, size_t size)
148 {
149 	struct spdk_jsonrpc_request *request;
150 	ssize_t rc;
151 	size_t len;
152 	void *end = NULL;
153 
154 	/* Check to see if we have received a full JSON value. It is safe to cast away const
155 	 * as we don't decode in place. */
156 	rc = spdk_json_parse((void *)json, size, NULL, 0, &end, 0);
157 	if (rc == SPDK_JSON_PARSE_INCOMPLETE) {
158 		return 0;
159 	}
160 
161 	request = calloc(1, sizeof(*request));
162 	if (request == NULL) {
163 		SPDK_DEBUGLOG(rpc, "Out of memory allocating request\n");
164 		return -1;
165 	}
166 
167 	conn->outstanding_requests++;
168 
169 	request->conn = conn;
170 
171 	len = end - json;
172 	request->recv_buffer = malloc(len + 1);
173 	if (request->recv_buffer == NULL) {
174 		SPDK_ERRLOG("Failed to allocate buffer to copy request (%zu bytes)\n", len + 1);
175 		jsonrpc_free_request(request);
176 		return -1;
177 	}
178 
179 	memcpy(request->recv_buffer, json, len);
180 	request->recv_buffer[len] = '\0';
181 
182 	if (rc > 0 && rc <= SPDK_JSONRPC_MAX_VALUES) {
183 		request->values_cnt = rc;
184 		request->values = malloc(request->values_cnt * sizeof(request->values[0]));
185 		if (request->values == NULL) {
186 			SPDK_ERRLOG("Failed to allocate buffer for JSON values (%zu bytes)\n",
187 				    request->values_cnt * sizeof(request->values[0]));
188 			jsonrpc_free_request(request);
189 			return -1;
190 		}
191 	}
192 
193 	request->send_offset = 0;
194 	request->send_len = 0;
195 	request->send_buf_size = SPDK_JSONRPC_SEND_BUF_SIZE_INIT;
196 	request->send_buf = malloc(request->send_buf_size);
197 	if (request->send_buf == NULL) {
198 		SPDK_ERRLOG("Failed to allocate send_buf (%zu bytes)\n", request->send_buf_size);
199 		jsonrpc_free_request(request);
200 		return -1;
201 	}
202 
203 	request->response = spdk_json_write_begin(jsonrpc_server_write_cb, request, 0);
204 	if (request->response == NULL) {
205 		SPDK_ERRLOG("Failed to allocate response JSON write context.\n");
206 		jsonrpc_free_request(request);
207 		return -1;
208 	}
209 
210 	if (rc <= 0 || rc > SPDK_JSONRPC_MAX_VALUES) {
211 		SPDK_DEBUGLOG(rpc, "JSON parse error\n");
212 		jsonrpc_server_handle_error(request, SPDK_JSONRPC_ERROR_PARSE_ERROR);
213 
214 		/*
215 		 * Can't recover from parse error (no guaranteed resync point in streaming JSON).
216 		 * Return an error to indicate that the connection should be closed.
217 		 */
218 		return -1;
219 	}
220 
221 	/* Decode a second time now that there is a full JSON value available. */
222 	rc = spdk_json_parse(request->recv_buffer, size, request->values, request->values_cnt, &end,
223 			     SPDK_JSON_PARSE_FLAG_DECODE_IN_PLACE);
224 	if (rc < 0 || rc > SPDK_JSONRPC_MAX_VALUES) {
225 		SPDK_DEBUGLOG(rpc, "JSON parse error on second pass\n");
226 		jsonrpc_server_handle_error(request, SPDK_JSONRPC_ERROR_PARSE_ERROR);
227 		return -1;
228 	}
229 
230 	assert(end != NULL);
231 
232 	if (request->values[0].type == SPDK_JSON_VAL_OBJECT_BEGIN) {
233 		parse_single_request(request, request->values);
234 	} else if (request->values[0].type == SPDK_JSON_VAL_ARRAY_BEGIN) {
235 		SPDK_DEBUGLOG(rpc, "Got batch array (not currently supported)\n");
236 		jsonrpc_server_handle_error(request, SPDK_JSONRPC_ERROR_INVALID_REQUEST);
237 	} else {
238 		SPDK_DEBUGLOG(rpc, "top-level JSON value was not array or object\n");
239 		jsonrpc_server_handle_error(request, SPDK_JSONRPC_ERROR_INVALID_REQUEST);
240 	}
241 
242 	return len;
243 }
244 
245 struct spdk_jsonrpc_server_conn *
246 spdk_jsonrpc_get_conn(struct spdk_jsonrpc_request *request)
247 {
248 	return request->conn;
249 }
250 
251 /* Never return NULL */
252 static struct spdk_json_write_ctx *
253 begin_response(struct spdk_jsonrpc_request *request)
254 {
255 	struct spdk_json_write_ctx *w = request->response;
256 
257 	spdk_json_write_object_begin(w);
258 	spdk_json_write_named_string(w, "jsonrpc", "2.0");
259 
260 	spdk_json_write_name(w, "id");
261 	if (request->id) {
262 		spdk_json_write_val(w, request->id);
263 	} else {
264 		spdk_json_write_null(w);
265 	}
266 
267 	return w;
268 }
269 
270 static void
271 skip_response(struct spdk_jsonrpc_request *request)
272 {
273 	request->send_len = 0;
274 	spdk_json_write_end(request->response);
275 	request->response = NULL;
276 	jsonrpc_server_send_response(request);
277 }
278 
279 static void
280 end_response(struct spdk_jsonrpc_request *request)
281 {
282 	spdk_json_write_object_end(request->response);
283 	spdk_json_write_end(request->response);
284 	request->response = NULL;
285 
286 	jsonrpc_server_write_cb(request, "\n", 1);
287 	jsonrpc_server_send_response(request);
288 }
289 
290 void
291 jsonrpc_free_request(struct spdk_jsonrpc_request *request)
292 {
293 	if (!request) {
294 		return;
295 	}
296 
297 	/* We must send or skip response explicitly */
298 	assert(request->response == NULL);
299 
300 	request->conn->outstanding_requests--;
301 	free(request->recv_buffer);
302 	free(request->values);
303 	free(request->send_buf);
304 	free(request);
305 }
306 
307 struct spdk_json_write_ctx *
308 spdk_jsonrpc_begin_result(struct spdk_jsonrpc_request *request)
309 {
310 	struct spdk_json_write_ctx *w = begin_response(request);
311 
312 	spdk_json_write_name(w, "result");
313 	return w;
314 }
315 
316 void
317 spdk_jsonrpc_end_result(struct spdk_jsonrpc_request *request, struct spdk_json_write_ctx *w)
318 {
319 	assert(w != NULL);
320 	assert(w == request->response);
321 
322 	/* If there was no ID in request we skip response. */
323 	if (request->id && request->id->type != SPDK_JSON_VAL_NULL) {
324 		end_response(request);
325 	} else {
326 		skip_response(request);
327 	}
328 }
329 
330 void
331 spdk_jsonrpc_send_bool_response(struct spdk_jsonrpc_request *request, bool value)
332 {
333 	struct spdk_json_write_ctx *w;
334 
335 	w = spdk_jsonrpc_begin_result(request);
336 	assert(w != NULL);
337 	spdk_json_write_bool(w, value);
338 	spdk_jsonrpc_end_result(request, w);
339 }
340 
341 void
342 spdk_jsonrpc_send_error_response(struct spdk_jsonrpc_request *request,
343 				 int error_code, const char *msg)
344 {
345 	struct spdk_json_write_ctx *w = begin_response(request);
346 
347 	spdk_json_write_named_object_begin(w, "error");
348 	spdk_json_write_named_int32(w, "code", error_code);
349 	spdk_json_write_named_string(w, "message", msg);
350 	spdk_json_write_object_end(w);
351 
352 	end_response(request);
353 }
354 
355 void
356 spdk_jsonrpc_send_error_response_fmt(struct spdk_jsonrpc_request *request,
357 				     int error_code, const char *fmt, ...)
358 {
359 	struct spdk_json_write_ctx *w = begin_response(request);
360 	va_list args;
361 
362 	spdk_json_write_named_object_begin(w, "error");
363 	spdk_json_write_named_int32(w, "code", error_code);
364 	va_start(args, fmt);
365 	spdk_json_write_named_string_fmt_v(w, "message", fmt, args);
366 	va_end(args);
367 	spdk_json_write_object_end(w);
368 
369 	end_response(request);
370 }
371 
372 SPDK_LOG_REGISTER_COMPONENT(rpc)
373