1 /* $OpenBSD$ */
2
3 /*
4 * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <sys/types.h>
20
21 #include <errno.h>
22 #include <pwd.h>
23 #include <stdio.h>
24 #include <string.h>
25 #include <stdlib.h>
26 #include <unistd.h>
27
28 #include "tmux.h"
29
30 /*
31 * Parse a command from a string.
32 */
33
34 int cmd_string_getc(const char *, size_t *);
35 void cmd_string_ungetc(size_t *);
36 void cmd_string_copy(char **, char *, size_t *);
37 char *cmd_string_string(const char *, size_t *, char, int);
38 char *cmd_string_variable(const char *, size_t *);
39 char *cmd_string_expand_tilde(const char *, size_t *);
40
41 int
cmd_string_getc(const char * s,size_t * p)42 cmd_string_getc(const char *s, size_t *p)
43 {
44 const u_char *ucs = s;
45
46 if (ucs[*p] == '\0')
47 return (EOF);
48 return (ucs[(*p)++]);
49 }
50
51 void
cmd_string_ungetc(size_t * p)52 cmd_string_ungetc(size_t *p)
53 {
54 (*p)--;
55 }
56
57 /*
58 * Parse command string. Returns -1 on error. If returning -1, cause is error
59 * string, or NULL for empty command.
60 */
61 int
cmd_string_parse(const char * s,struct cmd_list ** cmdlist,const char * file,u_int line,char ** cause)62 cmd_string_parse(const char *s, struct cmd_list **cmdlist, const char *file,
63 u_int line, char **cause)
64 {
65 size_t p;
66 int ch, i, argc, rval;
67 char **argv, *buf, *t;
68 const char *whitespace, *equals;
69 size_t len;
70
71 argv = NULL;
72 argc = 0;
73
74 buf = NULL;
75 len = 0;
76
77 *cause = NULL;
78
79 *cmdlist = NULL;
80 rval = -1;
81
82 p = 0;
83 for (;;) {
84 ch = cmd_string_getc(s, &p);
85 switch (ch) {
86 case '\'':
87 if ((t = cmd_string_string(s, &p, '\'', 0)) == NULL)
88 goto error;
89 cmd_string_copy(&buf, t, &len);
90 break;
91 case '"':
92 if ((t = cmd_string_string(s, &p, '"', 1)) == NULL)
93 goto error;
94 cmd_string_copy(&buf, t, &len);
95 break;
96 case '$':
97 if ((t = cmd_string_variable(s, &p)) == NULL)
98 goto error;
99 cmd_string_copy(&buf, t, &len);
100 break;
101 case '#':
102 /* Comment: discard rest of line. */
103 while ((ch = cmd_string_getc(s, &p)) != EOF)
104 ;
105 /* FALLTHROUGH */
106 case EOF:
107 case ' ':
108 case '\t':
109 if (buf != NULL) {
110 buf = xrealloc(buf, len + 1);
111 buf[len] = '\0';
112
113 argv = xreallocarray(argv, argc + 1,
114 sizeof *argv);
115 argv[argc++] = buf;
116
117 buf = NULL;
118 len = 0;
119 }
120
121 if (ch != EOF)
122 break;
123
124 while (argc != 0) {
125 equals = strchr(argv[0], '=');
126 whitespace = argv[0] + strcspn(argv[0], " \t");
127 if (equals == NULL || equals > whitespace)
128 break;
129 environ_put(global_environ, argv[0]);
130 argc--;
131 memmove(argv, argv + 1, argc * (sizeof *argv));
132 }
133 if (argc == 0)
134 goto out;
135
136 *cmdlist = cmd_list_parse(argc, argv, file, line, cause);
137 if (*cmdlist == NULL)
138 goto out;
139
140 rval = 0;
141 goto out;
142 case '~':
143 if (buf == NULL) {
144 t = cmd_string_expand_tilde(s, &p);
145 if (t == NULL)
146 goto error;
147 cmd_string_copy(&buf, t, &len);
148 break;
149 }
150 /* FALLTHROUGH */
151 default:
152 if (len >= SIZE_MAX - 2)
153 goto error;
154
155 buf = xrealloc(buf, len + 1);
156 buf[len++] = ch;
157 break;
158 }
159 }
160
161 error:
162 xasprintf(cause, "invalid or unknown command: %s", s);
163
164 out:
165 free(buf);
166
167 if (argv != NULL) {
168 for (i = 0; i < argc; i++)
169 free(argv[i]);
170 free(argv);
171 }
172
173 return (rval);
174 }
175
176 void
cmd_string_copy(char ** dst,char * src,size_t * len)177 cmd_string_copy(char **dst, char *src, size_t *len)
178 {
179 size_t srclen;
180
181 srclen = strlen(src);
182
183 *dst = xrealloc(*dst, *len + srclen + 1);
184 strlcpy(*dst + *len, src, srclen + 1);
185
186 *len += srclen;
187 free(src);
188 }
189
190 char *
cmd_string_string(const char * s,size_t * p,char endch,int esc)191 cmd_string_string(const char *s, size_t *p, char endch, int esc)
192 {
193 int ch;
194 char *buf, *t;
195 size_t len;
196
197 buf = NULL;
198 len = 0;
199
200 while ((ch = cmd_string_getc(s, p)) != endch) {
201 switch (ch) {
202 case EOF:
203 goto error;
204 case '\\':
205 if (!esc)
206 break;
207 switch (ch = cmd_string_getc(s, p)) {
208 case EOF:
209 goto error;
210 case 'e':
211 ch = '\033';
212 break;
213 case 'r':
214 ch = '\r';
215 break;
216 case 'n':
217 ch = '\n';
218 break;
219 case 't':
220 ch = '\t';
221 break;
222 }
223 break;
224 case '$':
225 if (!esc)
226 break;
227 if ((t = cmd_string_variable(s, p)) == NULL)
228 goto error;
229 cmd_string_copy(&buf, t, &len);
230 continue;
231 }
232
233 if (len >= SIZE_MAX - 2)
234 goto error;
235 buf = xrealloc(buf, len + 1);
236 buf[len++] = ch;
237 }
238
239 buf = xrealloc(buf, len + 1);
240 buf[len] = '\0';
241 return (buf);
242
243 error:
244 free(buf);
245 return (NULL);
246 }
247
248 char *
cmd_string_variable(const char * s,size_t * p)249 cmd_string_variable(const char *s, size_t *p)
250 {
251 int ch, fch;
252 char *buf, *t;
253 size_t len;
254 struct environ_entry *envent;
255
256 #define cmd_string_first(ch) ((ch) == '_' || \
257 ((ch) >= 'a' && (ch) <= 'z') || ((ch) >= 'A' && (ch) <= 'Z'))
258 #define cmd_string_other(ch) ((ch) == '_' || \
259 ((ch) >= 'a' && (ch) <= 'z') || ((ch) >= 'A' && (ch) <= 'Z') || \
260 ((ch) >= '0' && (ch) <= '9'))
261
262 buf = NULL;
263 len = 0;
264
265 fch = EOF;
266 switch (ch = cmd_string_getc(s, p)) {
267 case EOF:
268 goto error;
269 case '{':
270 fch = '{';
271
272 ch = cmd_string_getc(s, p);
273 if (!cmd_string_first(ch))
274 goto error;
275 /* FALLTHROUGH */
276 default:
277 if (!cmd_string_first(ch)) {
278 xasprintf(&t, "$%c", ch);
279 return (t);
280 }
281
282 buf = xrealloc(buf, len + 1);
283 buf[len++] = ch;
284
285 for (;;) {
286 ch = cmd_string_getc(s, p);
287 if (ch == EOF || !cmd_string_other(ch))
288 break;
289 else {
290 if (len >= SIZE_MAX - 3)
291 goto error;
292 buf = xrealloc(buf, len + 1);
293 buf[len++] = ch;
294 }
295 }
296 }
297
298 if (fch == '{' && ch != '}')
299 goto error;
300 if (ch != EOF && fch != '{')
301 cmd_string_ungetc(p); /* ch */
302
303 buf = xrealloc(buf, len + 1);
304 buf[len] = '\0';
305
306 envent = environ_find(global_environ, buf);
307 free(buf);
308 if (envent == NULL)
309 return (xstrdup(""));
310 return (xstrdup(envent->value));
311
312 error:
313 free(buf);
314 return (NULL);
315 }
316
317 char *
cmd_string_expand_tilde(const char * s,size_t * p)318 cmd_string_expand_tilde(const char *s, size_t *p)
319 {
320 struct passwd *pw;
321 struct environ_entry *envent;
322 char *home, *path, *user, *cp;
323 int last;
324
325 home = NULL;
326
327 last = cmd_string_getc(s, p);
328 if (last == EOF || last == '/' || last == ' '|| last == '\t') {
329 envent = environ_find(global_environ, "HOME");
330 if (envent != NULL && *envent->value != '\0')
331 home = envent->value;
332 else if ((pw = getpwuid(getuid())) != NULL)
333 home = pw->pw_dir;
334 } else {
335 cmd_string_ungetc(p);
336
337 cp = user = xmalloc(strlen(s));
338 for (;;) {
339 last = cmd_string_getc(s, p);
340 if (last == EOF || last == '/' || last == ' '|| last == '\t')
341 break;
342 *cp++ = last;
343 }
344 *cp = '\0';
345
346 if ((pw = getpwnam(user)) != NULL)
347 home = pw->pw_dir;
348 free(user);
349 }
350
351 if (home == NULL)
352 return (NULL);
353
354 if (last != EOF)
355 xasprintf(&path, "%s%c", home, last);
356 else
357 xasprintf(&path, "%s", home);
358 return (path);
359 }
360