xref: /spdk/lib/jsonrpc/jsonrpc_client.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 "spdk/util.h"
35 #include "jsonrpc_internal.h"
36 
37 static int
38 capture_version(const struct spdk_json_val *val, void *out)
39 {
40 	const struct spdk_json_val **vptr = out;
41 
42 	if (spdk_json_strequal(val, "2.0") != true) {
43 		return SPDK_JSON_PARSE_INVALID;
44 	}
45 
46 	*vptr = val;
47 	return 0;
48 }
49 
50 static int
51 capture_id(const struct spdk_json_val *val, void *out)
52 {
53 	const struct spdk_json_val **vptr = out;
54 
55 	if (val->type != SPDK_JSON_VAL_STRING && val->type != SPDK_JSON_VAL_NUMBER) {
56 		return -EINVAL;
57 	}
58 
59 	*vptr = val;
60 	return 0;
61 }
62 
63 static int
64 capture_any(const struct spdk_json_val *val, void *out)
65 {
66 	const struct spdk_json_val **vptr = out;
67 
68 	*vptr = val;
69 	return 0;
70 }
71 
72 static const struct spdk_json_object_decoder jsonrpc_response_decoders[] = {
73 	{"jsonrpc", offsetof(struct spdk_jsonrpc_client_response, version), capture_version},
74 	{"id", offsetof(struct spdk_jsonrpc_client_response, id), capture_id, true},
75 	{"result", offsetof(struct spdk_jsonrpc_client_response, result), capture_any, true},
76 	{"error", offsetof(struct spdk_jsonrpc_client_response, error), capture_any, true},
77 };
78 
79 int
80 jsonrpc_parse_response(struct spdk_jsonrpc_client *client)
81 {
82 	struct spdk_jsonrpc_client_response_internal *r;
83 	ssize_t rc;
84 	size_t buf_len;
85 	size_t values_cnt;
86 	void *end = NULL;
87 
88 
89 	/* Check to see if we have received a full JSON value. */
90 	rc = spdk_json_parse(client->recv_buf, client->recv_offset, NULL, 0, &end, 0);
91 	if (rc == SPDK_JSON_PARSE_INCOMPLETE) {
92 		return 0;
93 	}
94 
95 	SPDK_DEBUGLOG(rpc_client, "JSON string is :\n%s\n", client->recv_buf);
96 	if (rc < 0 || rc > SPDK_JSONRPC_CLIENT_MAX_VALUES) {
97 		SPDK_ERRLOG("JSON parse error (rc: %zd)\n", rc);
98 		/*
99 		 * Can't recover from parse error (no guaranteed resync point in streaming JSON).
100 		 * Return an error to indicate that the connection should be closed.
101 		 */
102 		return -EINVAL;
103 	}
104 
105 	values_cnt = rc;
106 
107 	r = calloc(1, sizeof(*r) + sizeof(struct spdk_json_val) * (values_cnt + 1));
108 	if (!r) {
109 		return -errno;
110 	}
111 
112 	if (client->resp) {
113 		free(r);
114 		return -ENOSPC;
115 	}
116 
117 	client->resp = r;
118 
119 	r->buf = client->recv_buf;
120 	buf_len = client->recv_offset;
121 	r->values_cnt = values_cnt;
122 
123 	client->recv_buf_size = 0;
124 	client->recv_offset = 0;
125 	client->recv_buf = NULL;
126 
127 	/* Decode a second time now that there is a full JSON value available. */
128 	rc = spdk_json_parse(r->buf, buf_len, r->values, values_cnt, &end,
129 			     SPDK_JSON_PARSE_FLAG_DECODE_IN_PLACE);
130 	if (rc != (ssize_t)values_cnt) {
131 		SPDK_ERRLOG("JSON parse error on second pass (rc: %zd, expected: %zu)\n", rc, values_cnt);
132 		goto err;
133 	}
134 
135 	assert(end != NULL);
136 
137 	if (r->values[0].type != SPDK_JSON_VAL_OBJECT_BEGIN) {
138 		SPDK_ERRLOG("top-level JSON value was not object\n");
139 		goto err;
140 	}
141 
142 	if (spdk_json_decode_object(r->values, jsonrpc_response_decoders,
143 				    SPDK_COUNTOF(jsonrpc_response_decoders), &r->jsonrpc)) {
144 		goto err;
145 	}
146 
147 	r->ready = 1;
148 	return 1;
149 
150 err:
151 	client->resp = NULL;
152 	spdk_jsonrpc_client_free_response(&r->jsonrpc);
153 	return -EINVAL;
154 }
155 
156 static int
157 jsonrpc_client_write_cb(void *cb_ctx, const void *data, size_t size)
158 {
159 	struct spdk_jsonrpc_client_request *request = cb_ctx;
160 	size_t new_size = request->send_buf_size;
161 
162 	while (new_size - request->send_len < size) {
163 		if (new_size >= SPDK_JSONRPC_SEND_BUF_SIZE_MAX) {
164 			SPDK_ERRLOG("Send buf exceeded maximum size (%zu)\n",
165 				    (size_t)SPDK_JSONRPC_SEND_BUF_SIZE_MAX);
166 			return -ENOSPC;
167 		}
168 
169 		new_size *= 2;
170 	}
171 
172 	if (new_size != request->send_buf_size) {
173 		uint8_t *new_buf;
174 
175 		new_buf = realloc(request->send_buf, new_size);
176 		if (new_buf == NULL) {
177 			SPDK_ERRLOG("Resizing send_buf failed (current size %zu, new size %zu)\n",
178 				    request->send_buf_size, new_size);
179 			return -ENOMEM;
180 		}
181 
182 		request->send_buf = new_buf;
183 		request->send_buf_size = new_size;
184 	}
185 
186 	memcpy(request->send_buf + request->send_len, data, size);
187 	request->send_len += size;
188 
189 	return 0;
190 }
191 
192 struct spdk_json_write_ctx *
193 spdk_jsonrpc_begin_request(struct spdk_jsonrpc_client_request *request, int32_t id,
194 			   const char *method)
195 {
196 	struct spdk_json_write_ctx *w;
197 
198 	w = spdk_json_write_begin(jsonrpc_client_write_cb, request, 0);
199 	if (w == NULL) {
200 		return NULL;
201 	}
202 
203 	spdk_json_write_object_begin(w);
204 	spdk_json_write_named_string(w, "jsonrpc", "2.0");
205 
206 	if (id >= 0) {
207 		spdk_json_write_named_int32(w, "id", id);
208 	}
209 
210 	if (method) {
211 		spdk_json_write_named_string(w, "method", method);
212 	}
213 
214 	return w;
215 }
216 
217 void
218 spdk_jsonrpc_end_request(struct spdk_jsonrpc_client_request *request, struct spdk_json_write_ctx *w)
219 {
220 	assert(w != NULL);
221 
222 	spdk_json_write_object_end(w);
223 	spdk_json_write_end(w);
224 	jsonrpc_client_write_cb(request, "\n", 1);
225 }
226 
227 SPDK_LOG_REGISTER_COMPONENT(rpc_client)
228