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5b708e0c RK |
1 | /* |
2 | * This file is part of DisOrder. | |
3 | * Copyright (C) 2004, 2005, 2007, 2008 Richard Kettlewell | |
4 | * | |
e7eb3a27 | 5 | * This program is free software: you can redistribute it and/or modify |
5b708e0c | 6 | * it under the terms of the GNU General Public License as published by |
e7eb3a27 | 7 | * the Free Software Foundation, either version 3 of the License, or |
5b708e0c | 8 | * (at your option) any later version. |
e7eb3a27 RK |
9 | * |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
5b708e0c | 15 | * You should have received a copy of the GNU General Public License |
e7eb3a27 | 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
5b708e0c RK |
17 | */ |
18 | /** @file lib/cgi.c | |
19 | * @brief CGI tools | |
20 | */ | |
21 | ||
05b75f8d | 22 | #include "common.h" |
5b708e0c | 23 | |
5b708e0c RK |
24 | #include <unistd.h> |
25 | #include <errno.h> | |
5b708e0c RK |
26 | |
27 | #include "cgi.h" | |
28 | #include "mem.h" | |
29 | #include "log.h" | |
30 | #include "vector.h" | |
31 | #include "hash.h" | |
32 | #include "kvp.h" | |
33 | #include "mime.h" | |
34 | #include "unicode.h" | |
35 | #include "sink.h" | |
36 | ||
37 | /** @brief Hash of arguments */ | |
38 | static hash *cgi_args; | |
39 | ||
40 | /** @brief Get CGI arguments from a GET request's query string */ | |
41 | static struct kvp *cgi__init_get(void) { | |
42 | const char *q; | |
43 | ||
44 | if((q = getenv("QUERY_STRING"))) | |
45 | return kvp_urldecode(q, strlen(q)); | |
46 | error(0, "QUERY_STRING not set, assuming empty"); | |
47 | return NULL; | |
48 | } | |
49 | ||
50 | /** @brief Read the HTTP request body */ | |
51 | static void cgi__input(char **ptrp, size_t *np) { | |
52 | const char *cl; | |
53 | char *q; | |
54 | size_t n, m = 0; | |
55 | int r; | |
56 | ||
57 | if(!(cl = getenv("CONTENT_LENGTH"))) | |
58 | fatal(0, "CONTENT_LENGTH not set"); | |
59 | n = atol(cl); | |
60 | /* We check for overflow and also limit the input to 16MB. Lower | |
61 | * would probably do. */ | |
62 | if(!(n+1) || n > 16 * 1024 * 1024) | |
63 | fatal(0, "input is much too large"); | |
64 | q = xmalloc_noptr(n + 1); | |
65 | while(m < n) { | |
66 | r = read(0, q + m, n - m); | |
67 | if(r > 0) | |
68 | m += r; | |
69 | else if(r == 0) | |
70 | fatal(0, "unexpected end of file reading request body"); | |
71 | else switch(errno) { | |
72 | case EINTR: break; | |
73 | default: fatal(errno, "error reading request body"); | |
74 | } | |
75 | } | |
76 | if(memchr(q, 0, n)) | |
77 | fatal(0, "null character in request body"); | |
78 | q[n + 1] = 0; | |
79 | *ptrp = q; | |
80 | if(np) | |
81 | *np = n; | |
82 | } | |
83 | ||
84 | /** @brief Called for each part header field (see cgi__part_callback()) */ | |
85 | static int cgi__field_callback(const char *name, const char *value, | |
86 | void *u) { | |
87 | char *disposition, *pname, *pvalue; | |
88 | char **namep = u; | |
89 | ||
90 | if(!strcmp(name, "content-disposition")) { | |
91 | if(mime_rfc2388_content_disposition(value, | |
92 | &disposition, | |
93 | &pname, | |
94 | &pvalue)) | |
95 | fatal(0, "error parsing Content-Disposition field"); | |
96 | if(!strcmp(disposition, "form-data") | |
97 | && pname | |
98 | && !strcmp(pname, "name")) { | |
99 | if(*namep) | |
100 | fatal(0, "duplicate Content-Disposition field"); | |
101 | *namep = pvalue; | |
102 | } | |
103 | } | |
104 | return 0; | |
105 | } | |
106 | ||
107 | /** @brief Called for each part (see cgi__init_multipart()) */ | |
108 | static int cgi__part_callback(const char *s, | |
109 | void *u) { | |
110 | char *name = 0; | |
111 | struct kvp *k, **head = u; | |
112 | ||
113 | if(!(s = mime_parse(s, cgi__field_callback, &name))) | |
114 | fatal(0, "error parsing part header"); | |
115 | if(!name) | |
116 | fatal(0, "no name found"); | |
117 | k = xmalloc(sizeof *k); | |
118 | k->next = *head; | |
119 | k->name = name; | |
120 | k->value = s; | |
121 | *head = k; | |
122 | return 0; | |
123 | } | |
124 | ||
125 | /** @brief Initialize CGI arguments from a multipart/form-data request body */ | |
126 | static struct kvp *cgi__init_multipart(const char *boundary) { | |
127 | char *q; | |
128 | struct kvp *head = 0; | |
129 | ||
130 | cgi__input(&q, 0); | |
131 | if(mime_multipart(q, cgi__part_callback, boundary, &head)) | |
132 | fatal(0, "invalid multipart object"); | |
133 | return head; | |
134 | } | |
135 | ||
136 | /** @brief Initialize CGI arguments from a POST request */ | |
137 | static struct kvp *cgi__init_post(void) { | |
138 | const char *ct, *boundary; | |
139 | char *q, *type; | |
140 | size_t n; | |
141 | struct kvp *k; | |
142 | ||
143 | if(!(ct = getenv("CONTENT_TYPE"))) | |
144 | ct = "application/x-www-form-urlencoded"; | |
145 | if(mime_content_type(ct, &type, &k)) | |
146 | fatal(0, "invalid content type '%s'", ct); | |
147 | if(!strcmp(type, "application/x-www-form-urlencoded")) { | |
148 | cgi__input(&q, &n); | |
149 | return kvp_urldecode(q, n); | |
150 | } | |
151 | if(!strcmp(type, "multipart/form-data")) { | |
152 | if(!(boundary = kvp_get(k, "boundary"))) | |
153 | fatal(0, "no boundary parameter found"); | |
154 | return cgi__init_multipart(boundary); | |
155 | } | |
156 | fatal(0, "unrecognized content type '%s'", type); | |
157 | } | |
158 | ||
159 | /** @brief Initialize CGI arguments | |
160 | * | |
161 | * Must be called before other cgi_ functions are used. | |
162 | * | |
163 | * This function can be called more than once, in which case it | |
164 | * revisits the environment and (perhaps) standard input. This is | |
165 | * only intended to be used for testing, actual CGI applications | |
166 | * should call it exactly once. | |
167 | */ | |
168 | void cgi_init(void) { | |
169 | const char *p; | |
170 | struct kvp *k; | |
171 | ||
172 | cgi_args = hash_new(sizeof (char *)); | |
173 | if(!(p = getenv("REQUEST_METHOD"))) | |
174 | error(0, "REQUEST_METHOD not set, assuming GET"); | |
175 | if(!p || !strcmp(p, "GET")) | |
176 | k = cgi__init_get(); | |
177 | else if(!strcmp(p, "POST")) | |
178 | k = cgi__init_post(); | |
179 | else | |
180 | fatal(0, "unknown request method %s", p); | |
181 | /* Validate the arguments and put them in a hash */ | |
182 | for(; k; k = k->next) { | |
183 | if(!utf8_valid(k->name, strlen(k->name)) | |
184 | || !utf8_valid(k->value, strlen(k->value))) | |
185 | error(0, "invalid UTF-8 sequence in cgi argument %s", k->name); | |
186 | else | |
187 | hash_add(cgi_args, k->name, &k->value, HASH_INSERT_OR_REPLACE); | |
188 | /* We just drop bogus arguments. */ | |
189 | } | |
190 | } | |
191 | ||
192 | /** @brief Get a CGI argument by name | |
193 | * | |
194 | * cgi_init() must be called first. Names and values are all valid | |
195 | * UTF-8 strings (and this is enforced at initialization time). | |
196 | */ | |
197 | const char *cgi_get(const char *name) { | |
198 | const char **v = hash_find(cgi_args, name); | |
199 | ||
200 | return v ? *v : NULL; | |
201 | } | |
202 | ||
5a7df048 RK |
203 | /** @brief Set a CGI argument */ |
204 | void cgi_set(const char *name, const char *value) { | |
205 | value = xstrdup(value); | |
206 | hash_add(cgi_args, name, &value, HASH_INSERT_OR_REPLACE); | |
207 | } | |
208 | ||
2cc4c0ef RK |
209 | /** @brief Clear CGI arguments */ |
210 | void cgi_clear(void) { | |
211 | cgi_args = hash_new(sizeof (char *)); | |
212 | } | |
213 | ||
5b708e0c RK |
214 | /** @brief Add SGML-style quoting |
215 | * @param src String to quote (UTF-8) | |
216 | * @return Quoted string | |
217 | * | |
218 | * Quotes characters for insertion into HTML output. Anything that is | |
219 | * not a printable ASCII character will be converted to a numeric | |
220 | * character references, as will '"', '&', '<' and '>' (since those | |
221 | * have special meanings). | |
222 | * | |
223 | * Quoting everything down to ASCII means we don't care what the | |
224 | * content encoding really is (as long as it's not anything insane | |
225 | * like EBCDIC). | |
226 | */ | |
227 | char *cgi_sgmlquote(const char *src) { | |
228 | uint32_t *ucs, c; | |
229 | int n; | |
230 | struct dynstr d[1]; | |
231 | struct sink *s; | |
232 | ||
233 | if(!(ucs = utf8_to_utf32(src, strlen(src), 0))) | |
234 | exit(1); | |
235 | dynstr_init(d); | |
236 | s = sink_dynstr(d); | |
237 | n = 1; | |
238 | /* format the string */ | |
239 | while((c = *ucs++)) { | |
240 | switch(c) { | |
241 | default: | |
242 | if(c > 126 || c < 32) { | |
243 | case '"': | |
244 | case '&': | |
245 | case '<': | |
246 | case '>': | |
247 | /* For simplicity we always use numeric character references | |
248 | * even if a named reference is available. */ | |
249 | sink_printf(s, "&#%"PRIu32";", c); | |
250 | break; | |
251 | } else | |
252 | sink_writec(s, (char)c); | |
253 | } | |
254 | } | |
255 | dynstr_terminate(d); | |
256 | return d->vec; | |
257 | } | |
258 | ||
5b708e0c RK |
259 | /** @brief Construct a URL |
260 | * @param url Base URL | |
261 | * @param ... Name/value pairs for constructed query string | |
262 | * @return Constructed URL | |
263 | * | |
264 | * The name/value pair list is terminated by a single (char *)0. | |
265 | */ | |
266 | char *cgi_makeurl(const char *url, ...) { | |
267 | va_list ap; | |
268 | struct kvp *kvp, *k, **kk = &kvp; | |
269 | struct dynstr d; | |
270 | const char *n, *v; | |
271 | ||
272 | dynstr_init(&d); | |
273 | dynstr_append_string(&d, url); | |
274 | va_start(ap, url); | |
275 | while((n = va_arg(ap, const char *))) { | |
276 | v = va_arg(ap, const char *); | |
277 | *kk = k = xmalloc(sizeof *k); | |
278 | kk = &k->next; | |
279 | k->name = n; | |
280 | k->value = v; | |
281 | } | |
282 | va_end(ap); | |
283 | *kk = 0; | |
284 | if(kvp) { | |
285 | dynstr_append(&d, '?'); | |
286 | dynstr_append_string(&d, kvp_urlencode(kvp, 0)); | |
287 | } | |
288 | dynstr_terminate(&d); | |
289 | return d.vec; | |
290 | } | |
291 | ||
9faa7a88 RK |
292 | /** @brief Construct a URL from current parameters |
293 | * @param url Base URL | |
294 | * @return Constructed URL | |
295 | */ | |
296 | char *cgi_thisurl(const char *url) { | |
297 | struct dynstr d[1]; | |
298 | char **keys = hash_keys(cgi_args); | |
299 | int n; | |
300 | ||
301 | dynstr_init(d); | |
302 | dynstr_append_string(d, url); | |
e7ce7665 RK |
303 | for(n = 0; keys[n]; ++n) { |
304 | dynstr_append(d, n ? '&' : '?'); | |
305 | dynstr_append_string(d, urlencodestring(keys[n])); | |
306 | dynstr_append(d, '='); | |
2cc4c0ef | 307 | dynstr_append_string(d, urlencodestring(cgi_get(keys[n]))); |
9faa7a88 RK |
308 | } |
309 | dynstr_terminate(d); | |
310 | return d->vec; | |
311 | } | |
312 | ||
5b708e0c RK |
313 | /* |
314 | Local Variables: | |
315 | c-basic-offset:2 | |
316 | comment-column:40 | |
317 | fill-column:79 | |
318 | indent-tabs-mode:nil | |
319 | End: | |
320 | */ |