xref: /spdk/lib/jsonrpc/jsonrpc_server.c (revision e3b90fe2d512a694f950666fad49b08a2042b824)
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 
66 	if (spdk_json_decode_object(values, jsonrpc_request_decoders,
67 				    SPDK_COUNTOF(jsonrpc_request_decoders),
68 				    &req)) {
69 		goto invalid;
70 	}
71 
72 	if (req.version && (req.version->type != SPDK_JSON_VAL_STRING ||
73 			    !spdk_json_strequal(req.version, "2.0"))) {
74 		goto invalid;
75 	}
76 
77 	if (!req.method || req.method->type != SPDK_JSON_VAL_STRING) {
78 		goto invalid;
79 	}
80 
81 	if (req.id) {
82 		if (req.id->type == SPDK_JSON_VAL_STRING ||
83 		    req.id->type == SPDK_JSON_VAL_NUMBER ||
84 		    req.id->type == SPDK_JSON_VAL_NULL) {
85 			request->id = req.id;
86 		} else  {
87 			goto invalid;
88 		}
89 	}
90 
91 	if (req.params) {
92 		if (req.params->type != SPDK_JSON_VAL_ARRAY_BEGIN &&
93 		    req.params->type != SPDK_JSON_VAL_OBJECT_BEGIN) {
94 			goto invalid;
95 		}
96 	}
97 
98 	spdk_jsonrpc_server_handle_request(request, req.method, req.params);
99 	return;
100 
101 invalid:
102 	spdk_jsonrpc_server_handle_error(request, SPDK_JSONRPC_ERROR_INVALID_REQUEST);
103 }
104 
105 static int
106 spdk_jsonrpc_server_write_cb(void *cb_ctx, const void *data, size_t size)
107 {
108 	struct spdk_jsonrpc_request *request = cb_ctx;
109 	size_t new_size = request->send_buf_size;
110 
111 	while (new_size - request->send_len < size) {
112 		if (new_size >= SPDK_JSONRPC_SEND_BUF_SIZE_MAX) {
113 			SPDK_ERRLOG("Send buf exceeded maximum size (%zu)\n",
114 				    (size_t)SPDK_JSONRPC_SEND_BUF_SIZE_MAX);
115 			return -1;
116 		}
117 
118 		new_size *= 2;
119 	}
120 
121 	if (new_size != request->send_buf_size) {
122 		uint8_t *new_buf;
123 
124 		new_buf = realloc(request->send_buf, new_size);
125 		if (new_buf == NULL) {
126 			SPDK_ERRLOG("Resizing send_buf failed (current size %zu, new size %zu)\n",
127 				    request->send_buf_size, new_size);
128 			return -1;
129 		}
130 
131 		request->send_buf = new_buf;
132 		request->send_buf_size = new_size;
133 	}
134 
135 	memcpy(request->send_buf + request->send_len, data, size);
136 	request->send_len += size;
137 
138 	return 0;
139 }
140 
141 int
142 spdk_jsonrpc_parse_request(struct spdk_jsonrpc_server_conn *conn, const void *json, size_t size)
143 {
144 	struct spdk_jsonrpc_request *request;
145 	ssize_t rc;
146 	size_t len;
147 	void *end = NULL;
148 
149 	/* Check to see if we have received a full JSON value. It is safe to cast away const
150 	 * as we don't decode in place. */
151 	rc = spdk_json_parse((void *)json, size, NULL, 0, &end, 0);
152 	if (rc == SPDK_JSON_PARSE_INCOMPLETE) {
153 		return 0;
154 	}
155 
156 	request = calloc(1, sizeof(*request));
157 	if (request == NULL) {
158 		SPDK_DEBUGLOG(SPDK_LOG_RPC, "Out of memory allocating request\n");
159 		return -1;
160 	}
161 
162 	conn->outstanding_requests++;
163 
164 	request->conn = conn;
165 
166 	len = end - json;
167 	request->recv_buffer = malloc(len + 1);
168 	if (request->recv_buffer == NULL) {
169 		SPDK_ERRLOG("Failed to allocate buffer to copy request (%zu bytes)\n", len + 1);
170 		spdk_jsonrpc_free_request(request);
171 		return -1;
172 	}
173 
174 	memcpy(request->recv_buffer, json, len);
175 	request->recv_buffer[len] = '\0';
176 
177 	if (rc > 0 && rc <= SPDK_JSONRPC_MAX_VALUES) {
178 		request->values_cnt = rc;
179 		request->values = malloc(request->values_cnt * sizeof(request->values[0]));
180 		if (request->values == NULL) {
181 			SPDK_ERRLOG("Failed to allocate buffer for JSON values (%zu bytes)\n",
182 				    request->values_cnt * sizeof(request->values[0]));
183 			spdk_jsonrpc_free_request(request);
184 			return -1;
185 		}
186 	}
187 
188 	request->send_offset = 0;
189 	request->send_len = 0;
190 	request->send_buf_size = SPDK_JSONRPC_SEND_BUF_SIZE_INIT;
191 	request->send_buf = malloc(request->send_buf_size);
192 	if (request->send_buf == NULL) {
193 		SPDK_ERRLOG("Failed to allocate send_buf (%zu bytes)\n", request->send_buf_size);
194 		spdk_jsonrpc_free_request(request);
195 		return -1;
196 	}
197 
198 	request->response = spdk_json_write_begin(spdk_jsonrpc_server_write_cb, request, 0);
199 	if (request->response == NULL) {
200 		SPDK_ERRLOG("Failed to allocate response JSON write context.\n");
201 		spdk_jsonrpc_free_request(request);
202 		return -1;
203 	}
204 
205 	if (rc <= 0 || rc > SPDK_JSONRPC_MAX_VALUES) {
206 		SPDK_DEBUGLOG(SPDK_LOG_RPC, "JSON parse error\n");
207 		spdk_jsonrpc_server_handle_error(request, SPDK_JSONRPC_ERROR_PARSE_ERROR);
208 
209 		/*
210 		 * Can't recover from parse error (no guaranteed resync point in streaming JSON).
211 		 * Return an error to indicate that the connection should be closed.
212 		 */
213 		return -1;
214 	}
215 
216 	/* Decode a second time now that there is a full JSON value available. */
217 	rc = spdk_json_parse(request->recv_buffer, size, request->values, request->values_cnt, &end,
218 			     SPDK_JSON_PARSE_FLAG_DECODE_IN_PLACE);
219 	if (rc < 0 || rc > SPDK_JSONRPC_MAX_VALUES) {
220 		SPDK_DEBUGLOG(SPDK_LOG_RPC, "JSON parse error on second pass\n");
221 		spdk_jsonrpc_server_handle_error(request, SPDK_JSONRPC_ERROR_PARSE_ERROR);
222 		return -1;
223 	}
224 
225 	assert(end != NULL);
226 
227 	if (request->values[0].type == SPDK_JSON_VAL_OBJECT_BEGIN) {
228 		parse_single_request(request, request->values);
229 	} else if (request->values[0].type == SPDK_JSON_VAL_ARRAY_BEGIN) {
230 		SPDK_DEBUGLOG(SPDK_LOG_RPC, "Got batch array (not currently supported)\n");
231 		spdk_jsonrpc_server_handle_error(request, SPDK_JSONRPC_ERROR_INVALID_REQUEST);
232 	} else {
233 		SPDK_DEBUGLOG(SPDK_LOG_RPC, "top-level JSON value was not array or object\n");
234 		spdk_jsonrpc_server_handle_error(request, SPDK_JSONRPC_ERROR_INVALID_REQUEST);
235 	}
236 
237 	return len;
238 }
239 
240 struct spdk_jsonrpc_server_conn *
241 spdk_jsonrpc_get_conn(struct spdk_jsonrpc_request *request)
242 {
243 	return request->conn;
244 }
245 
246 /* Never return NULL */
247 static struct spdk_json_write_ctx *
248 begin_response(struct spdk_jsonrpc_request *request)
249 {
250 	struct spdk_json_write_ctx *w = request->response;
251 
252 	spdk_json_write_object_begin(w);
253 	spdk_json_write_named_string(w, "jsonrpc", "2.0");
254 
255 	spdk_json_write_name(w, "id");
256 	if (request->id) {
257 		spdk_json_write_val(w, request->id);
258 	} else {
259 		spdk_json_write_null(w);
260 	}
261 
262 	return w;
263 }
264 
265 static void
266 skip_response(struct spdk_jsonrpc_request *request)
267 {
268 	request->send_len = 0;
269 	spdk_json_write_end(request->response);
270 	request->response = NULL;
271 	spdk_jsonrpc_server_send_response(request);
272 }
273 
274 static void
275 end_response(struct spdk_jsonrpc_request *request)
276 {
277 	spdk_json_write_object_end(request->response);
278 	spdk_json_write_end(request->response);
279 	request->response = NULL;
280 
281 	spdk_jsonrpc_server_write_cb(request, "\n", 1);
282 	spdk_jsonrpc_server_send_response(request);
283 }
284 
285 void
286 spdk_jsonrpc_free_request(struct spdk_jsonrpc_request *request)
287 {
288 	if (!request) {
289 		return;
290 	}
291 
292 	/* We must send or skip response explicitly */
293 	assert(request->response == NULL);
294 
295 	request->conn->outstanding_requests--;
296 	free(request->recv_buffer);
297 	free(request->values);
298 	free(request->send_buf);
299 	free(request);
300 }
301 
302 struct spdk_json_write_ctx *
303 spdk_jsonrpc_begin_result(struct spdk_jsonrpc_request *request)
304 {
305 	struct spdk_json_write_ctx *w = begin_response(request);
306 
307 	spdk_json_write_name(w, "result");
308 	return w;
309 }
310 
311 void
312 spdk_jsonrpc_end_result(struct spdk_jsonrpc_request *request, struct spdk_json_write_ctx *w)
313 {
314 	assert(w != NULL);
315 	assert(w == request->response);
316 
317 	/* If there was no ID in request we skip response. */
318 	if (request->id && request->id->type != SPDK_JSON_VAL_NULL) {
319 		end_response(request);
320 	} else {
321 		skip_response(request);
322 	}
323 }
324 
325 void
326 spdk_jsonrpc_send_error_response(struct spdk_jsonrpc_request *request,
327 				 int error_code, const char *msg)
328 {
329 	struct spdk_json_write_ctx *w = begin_response(request);
330 
331 	spdk_json_write_named_object_begin(w, "error");
332 	spdk_json_write_named_int32(w, "code", error_code);
333 	spdk_json_write_named_string(w, "message", msg);
334 	spdk_json_write_object_end(w);
335 
336 	end_response(request);
337 }
338 
339 void
340 spdk_jsonrpc_send_error_response_fmt(struct spdk_jsonrpc_request *request,
341 				     int error_code, const char *fmt, ...)
342 {
343 	struct spdk_json_write_ctx *w = begin_response(request);
344 	va_list args;
345 
346 	spdk_json_write_named_object_begin(w, "error");
347 	spdk_json_write_named_int32(w, "code", error_code);
348 	va_start(args, fmt);
349 	spdk_json_write_named_string_fmt_v(w, "message", fmt, args);
350 	va_end(args);
351 	spdk_json_write_object_end(w);
352 
353 	end_response(request);
354 }
355 
356 SPDK_LOG_REGISTER_COMPONENT("rpc", SPDK_LOG_RPC)
357