1 /*
2 *
3 * Copyright 2015 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19 #include <grpc/support/port_platform.h>
20
21 #include "src/core/ext/filters/client_channel/uri_parser.h"
22
23 #include <string.h>
24
25 #include <grpc/slice_buffer.h>
26 #include <grpc/support/alloc.h>
27 #include <grpc/support/log.h>
28 #include <grpc/support/string_util.h>
29
30 #include "src/core/lib/gpr/string.h"
31 #include "src/core/lib/slice/percent_encoding.h"
32 #include "src/core/lib/slice/slice_internal.h"
33 #include "src/core/lib/slice/slice_string_helpers.h"
34
35 /** a size_t default value... maps to all 1's */
36 #define NOT_SET (~(size_t)0)
37
bad_uri(const char * uri_text,size_t pos,const char * section,bool suppress_errors)38 static grpc_uri* bad_uri(const char* uri_text, size_t pos, const char* section,
39 bool suppress_errors) {
40 char* line_prefix;
41 size_t pfx_len;
42
43 if (!suppress_errors) {
44 gpr_asprintf(&line_prefix, "bad uri.%s: '", section);
45 pfx_len = strlen(line_prefix) + pos;
46 gpr_log(GPR_ERROR, "%s%s'", line_prefix, uri_text);
47 gpr_free(line_prefix);
48
49 line_prefix = static_cast<char*>(gpr_malloc(pfx_len + 1));
50 memset(line_prefix, ' ', pfx_len);
51 line_prefix[pfx_len] = 0;
52 gpr_log(GPR_ERROR, "%s^ here", line_prefix);
53 gpr_free(line_prefix);
54 }
55
56 return nullptr;
57 }
58
59 /** Returns a copy of percent decoded \a src[begin, end) */
decode_and_copy_component(const char * src,size_t begin,size_t end)60 static char* decode_and_copy_component(const char* src, size_t begin,
61 size_t end) {
62 grpc_slice component =
63 (begin == NOT_SET || end == NOT_SET)
64 ? grpc_empty_slice()
65 : grpc_slice_from_copied_buffer(src + begin, end - begin);
66 grpc_slice decoded_component =
67 grpc_permissive_percent_decode_slice(component);
68 char* out = grpc_dump_slice(decoded_component, GPR_DUMP_ASCII);
69 grpc_slice_unref_internal(component);
70 grpc_slice_unref_internal(decoded_component);
71 return out;
72 }
73
valid_hex(char c)74 static bool valid_hex(char c) {
75 return ((c >= 'a') && (c <= 'f')) || ((c >= 'A') && (c <= 'F')) ||
76 ((c >= '0') && (c <= '9'));
77 }
78
79 /** Returns how many chars to advance if \a uri_text[i] begins a valid \a pchar
80 * production. If \a uri_text[i] introduces an invalid \a pchar (such as percent
81 * sign not followed by two hex digits), NOT_SET is returned. */
parse_pchar(const char * uri_text,size_t i)82 static size_t parse_pchar(const char* uri_text, size_t i) {
83 /* pchar = unreserved / pct-encoded / sub-delims / ":" / "@"
84 * unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
85 * pct-encoded = "%" HEXDIG HEXDIG
86 * sub-delims = "!" / "$" / "&" / "'" / "(" / ")"
87 / "*" / "+" / "," / ";" / "=" */
88 char c = uri_text[i];
89 switch (c) {
90 default:
91 if (((c >= 'a') && (c <= 'z')) || ((c >= 'A') && (c <= 'Z')) ||
92 ((c >= '0') && (c <= '9'))) {
93 return 1;
94 }
95 break;
96 case ':':
97 case '@':
98 case '-':
99 case '.':
100 case '_':
101 case '~':
102 case '!':
103 case '$':
104 case '&':
105 case '\'':
106 case '(':
107 case ')':
108 case '*':
109 case '+':
110 case ',':
111 case ';':
112 case '=':
113 return 1;
114 case '%': /* pct-encoded */
115 if (valid_hex(uri_text[i + 1]) && valid_hex(uri_text[i + 2])) {
116 return 2;
117 }
118 return NOT_SET;
119 }
120 return 0;
121 }
122
123 /* *( pchar / "?" / "/" ) */
parse_fragment_or_query(const char * uri_text,size_t * i)124 static int parse_fragment_or_query(const char* uri_text, size_t* i) {
125 char c;
126 while ((c = uri_text[*i]) != 0) {
127 const size_t advance = parse_pchar(uri_text, *i); /* pchar */
128 switch (advance) {
129 case 0: /* uri_text[i] isn't in pchar */
130 /* maybe it's ? or / */
131 if (uri_text[*i] == '?' || uri_text[*i] == '/') {
132 (*i)++;
133 break;
134 } else {
135 return 1;
136 }
137 GPR_UNREACHABLE_CODE(return 0);
138 default:
139 (*i) += advance;
140 break;
141 case NOT_SET: /* uri_text[i] introduces an invalid URI */
142 return 0;
143 }
144 }
145 /* *i is the first uri_text position past the \a query production, maybe \0 */
146 return 1;
147 }
148
parse_query_parts(grpc_uri * uri)149 static void parse_query_parts(grpc_uri* uri) {
150 static const char* QUERY_PARTS_SEPARATOR = "&";
151 static const char* QUERY_PARTS_VALUE_SEPARATOR = "=";
152 GPR_ASSERT(uri->query != nullptr);
153 if (uri->query[0] == '\0') {
154 uri->query_parts = nullptr;
155 uri->query_parts_values = nullptr;
156 uri->num_query_parts = 0;
157 return;
158 }
159
160 gpr_string_split(uri->query, QUERY_PARTS_SEPARATOR, &uri->query_parts,
161 &uri->num_query_parts);
162 uri->query_parts_values =
163 static_cast<char**>(gpr_malloc(uri->num_query_parts * sizeof(char**)));
164 for (size_t i = 0; i < uri->num_query_parts; i++) {
165 char** query_param_parts;
166 size_t num_query_param_parts;
167 char* full = uri->query_parts[i];
168 gpr_string_split(full, QUERY_PARTS_VALUE_SEPARATOR, &query_param_parts,
169 &num_query_param_parts);
170 GPR_ASSERT(num_query_param_parts > 0);
171 uri->query_parts[i] = query_param_parts[0];
172 if (num_query_param_parts > 1) {
173 /* TODO(dgq): only the first value after the separator is considered.
174 * Perhaps all chars after the first separator for the query part should
175 * be included, even if they include the separator. */
176 uri->query_parts_values[i] = query_param_parts[1];
177 } else {
178 uri->query_parts_values[i] = nullptr;
179 }
180 for (size_t j = 2; j < num_query_param_parts; j++) {
181 gpr_free(query_param_parts[j]);
182 }
183 gpr_free(query_param_parts);
184 gpr_free(full);
185 }
186 }
187
grpc_uri_parse(const char * uri_text,bool suppress_errors)188 grpc_uri* grpc_uri_parse(const char* uri_text, bool suppress_errors) {
189 grpc_uri* uri;
190 size_t scheme_begin = 0;
191 size_t scheme_end = NOT_SET;
192 size_t authority_begin = NOT_SET;
193 size_t authority_end = NOT_SET;
194 size_t path_begin = NOT_SET;
195 size_t path_end = NOT_SET;
196 size_t query_begin = NOT_SET;
197 size_t query_end = NOT_SET;
198 size_t fragment_begin = NOT_SET;
199 size_t fragment_end = NOT_SET;
200 size_t i;
201
202 for (i = scheme_begin; uri_text[i] != 0; i++) {
203 if (uri_text[i] == ':') {
204 scheme_end = i;
205 break;
206 }
207 if (uri_text[i] >= 'a' && uri_text[i] <= 'z') continue;
208 if (uri_text[i] >= 'A' && uri_text[i] <= 'Z') continue;
209 if (i != scheme_begin) {
210 if (uri_text[i] >= '0' && uri_text[i] <= '9') continue;
211 if (uri_text[i] == '+') continue;
212 if (uri_text[i] == '-') continue;
213 if (uri_text[i] == '.') continue;
214 }
215 break;
216 }
217 if (scheme_end == NOT_SET) {
218 return bad_uri(uri_text, i, "scheme", suppress_errors);
219 }
220
221 if (uri_text[scheme_end + 1] == '/' && uri_text[scheme_end + 2] == '/') {
222 authority_begin = scheme_end + 3;
223 for (i = authority_begin; uri_text[i] != 0 && authority_end == NOT_SET;
224 i++) {
225 if (uri_text[i] == '/' || uri_text[i] == '?' || uri_text[i] == '#') {
226 authority_end = i;
227 }
228 }
229 if (authority_end == NOT_SET && uri_text[i] == 0) {
230 authority_end = i;
231 }
232 if (authority_end == NOT_SET) {
233 return bad_uri(uri_text, i, "authority", suppress_errors);
234 }
235 /* TODO(ctiller): parse the authority correctly */
236 path_begin = authority_end;
237 } else {
238 path_begin = scheme_end + 1;
239 }
240
241 for (i = path_begin; uri_text[i] != 0; i++) {
242 if (uri_text[i] == '?' || uri_text[i] == '#') {
243 path_end = i;
244 break;
245 }
246 }
247 if (path_end == NOT_SET && uri_text[i] == 0) {
248 path_end = i;
249 }
250 if (path_end == NOT_SET) {
251 return bad_uri(uri_text, i, "path", suppress_errors);
252 }
253
254 if (uri_text[i] == '?') {
255 query_begin = ++i;
256 if (!parse_fragment_or_query(uri_text, &i)) {
257 return bad_uri(uri_text, i, "query", suppress_errors);
258 } else if (uri_text[i] != 0 && uri_text[i] != '#') {
259 /* We must be at the end or at the beginning of a fragment */
260 return bad_uri(uri_text, i, "query", suppress_errors);
261 }
262 query_end = i;
263 }
264 if (uri_text[i] == '#') {
265 fragment_begin = ++i;
266 if (!parse_fragment_or_query(uri_text, &i)) {
267 return bad_uri(uri_text, i - fragment_end, "fragment", suppress_errors);
268 } else if (uri_text[i] != 0) {
269 /* We must be at the end */
270 return bad_uri(uri_text, i, "fragment", suppress_errors);
271 }
272 fragment_end = i;
273 }
274
275 uri = static_cast<grpc_uri*>(gpr_zalloc(sizeof(*uri)));
276 uri->scheme = decode_and_copy_component(uri_text, scheme_begin, scheme_end);
277 uri->authority =
278 decode_and_copy_component(uri_text, authority_begin, authority_end);
279 uri->path = decode_and_copy_component(uri_text, path_begin, path_end);
280 uri->query = decode_and_copy_component(uri_text, query_begin, query_end);
281 uri->fragment =
282 decode_and_copy_component(uri_text, fragment_begin, fragment_end);
283 parse_query_parts(uri);
284
285 return uri;
286 }
287
grpc_uri_get_query_arg(const grpc_uri * uri,const char * key)288 const char* grpc_uri_get_query_arg(const grpc_uri* uri, const char* key) {
289 GPR_ASSERT(key != nullptr);
290 if (key[0] == '\0') return nullptr;
291
292 for (size_t i = 0; i < uri->num_query_parts; ++i) {
293 if (0 == strcmp(key, uri->query_parts[i])) {
294 return uri->query_parts_values[i];
295 }
296 }
297 return nullptr;
298 }
299
grpc_uri_destroy(grpc_uri * uri)300 void grpc_uri_destroy(grpc_uri* uri) {
301 if (!uri) return;
302 gpr_free(uri->scheme);
303 gpr_free(uri->authority);
304 gpr_free(uri->path);
305 gpr_free(uri->query);
306 for (size_t i = 0; i < uri->num_query_parts; ++i) {
307 gpr_free(uri->query_parts[i]);
308 gpr_free(uri->query_parts_values[i]);
309 }
310 gpr_free(uri->query_parts);
311 gpr_free(uri->query_parts_values);
312 gpr_free(uri->fragment);
313 gpr_free(uri);
314 }
315