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1.17 ! tedu 1: /* $OpenBSD: parse.y,v 1.16 2016/06/05 00:46:34 djm Exp $ */
1.1 tedu 2: /*
3: * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: */
17:
18: %{
19: #include <sys/types.h>
20: #include <ctype.h>
21: #include <unistd.h>
22: #include <stdint.h>
23: #include <stdarg.h>
24: #include <stdio.h>
25: #include <string.h>
26: #include <err.h>
27:
28: #include "doas.h"
29:
30: typedef struct {
31: union {
32: struct {
33: int action;
34: int options;
1.7 zhuk 35: const char *cmd;
36: const char **cmdargs;
1.1 tedu 37: const char **envlist;
38: };
39: const char *str;
40: };
1.10 zhuk 41: int lineno;
42: int colno;
1.1 tedu 43: } yystype;
44: #define YYSTYPE yystype
45:
46: FILE *yyfp;
47:
48: struct rule **rules;
49: int nrules, maxrules;
1.10 zhuk 50: int parse_errors = 0;
1.1 tedu 51:
1.4 nicm 52: void yyerror(const char *, ...);
53: int yylex(void);
54: int yyparse(void);
55:
1.1 tedu 56: %}
57:
1.7 zhuk 58: %token TPERMIT TDENY TAS TCMD TARGS
1.17 ! tedu 59: %token TNOPASS TKEEPENV
1.1 tedu 60: %token TSTRING
61:
62: %%
63:
64: grammar: /* empty */
65: | grammar '\n'
66: | grammar rule '\n'
1.10 zhuk 67: | error '\n'
1.1 tedu 68: ;
69:
70: rule: action ident target cmd {
71: struct rule *r;
72: r = calloc(1, sizeof(*r));
1.2 nicm 73: if (!r)
74: errx(1, "can't allocate rule");
1.1 tedu 75: r->action = $1.action;
76: r->options = $1.options;
77: r->envlist = $1.envlist;
78: r->ident = $2.str;
79: r->target = $3.str;
1.7 zhuk 80: r->cmd = $4.cmd;
81: r->cmdargs = $4.cmdargs;
1.1 tedu 82: if (nrules == maxrules) {
83: if (maxrules == 0)
84: maxrules = 63;
85: else
86: maxrules *= 2;
1.6 benno 87: if (!(rules = reallocarray(rules, maxrules,
88: sizeof(*rules))))
1.1 tedu 89: errx(1, "can't allocate rules");
90: }
91: rules[nrules++] = r;
92: } ;
93:
94: action: TPERMIT options {
95: $$.action = PERMIT;
96: $$.options = $2.options;
97: $$.envlist = $2.envlist;
98: } | TDENY {
99: $$.action = DENY;
100: } ;
101:
102: options: /* none */
103: | options option {
104: $$.options = $1.options | $2.options;
105: $$.envlist = $1.envlist;
106: if ($2.envlist) {
1.10 zhuk 107: if ($$.envlist) {
108: yyerror("can't have two keepenv sections");
109: YYERROR;
110: } else
1.1 tedu 111: $$.envlist = $2.envlist;
112: }
113: } ;
1.16 djm 114:
1.1 tedu 115: option: TNOPASS {
116: $$.options = NOPASS;
117: } | TKEEPENV {
118: $$.options = KEEPENV;
119: } | TKEEPENV '{' envlist '}' {
120: $$.options = KEEPENV;
121: $$.envlist = $3.envlist;
122: } ;
123:
124: envlist: /* empty */ {
125: if (!($$.envlist = calloc(1, sizeof(char *))))
126: errx(1, "can't allocate envlist");
127: } | envlist TSTRING {
128: int nenv = arraylen($1.envlist);
1.6 benno 129: if (!($$.envlist = reallocarray($1.envlist, nenv + 2,
130: sizeof(char *))))
1.1 tedu 131: errx(1, "can't allocate envlist");
132: $$.envlist[nenv] = $2.str;
133: $$.envlist[nenv + 1] = NULL;
1.17 ! tedu 134: } | envlist TSTRING '=' TSTRING {
! 135: int nenv = arraylen($1.envlist);
1.16 djm 136: char *cp = NULL;
137:
138: if (*$2.str == '\0' || strchr($2.str, '=') != NULL) {
139: yyerror("invalid setenv expression");
140: YYERROR;
141: }
1.17 ! tedu 142: if (!($$.envlist = reallocarray($1.envlist,
1.16 djm 143: nenv + 2, sizeof(char *))))
144: errx(1, "can't allocate envlist");
1.17 ! tedu 145: $$.envlist[nenv] = NULL;
1.16 djm 146: if (asprintf(&cp, "%s=%s", $2.str, $4.str) <= 0 ||
147: cp == NULL)
148: errx(1,"asprintf failed");
1.17 ! tedu 149: $$.envlist[nenv] = cp;
! 150: $$.envlist[nenv + 1] = NULL;
1.16 djm 151: }
152:
1.1 tedu 153: ident: TSTRING {
154: $$.str = $1.str;
155: } ;
156:
157: target: /* optional */ {
158: $$.str = NULL;
159: } | TAS TSTRING {
160: $$.str = $2.str;
161: } ;
162:
163: cmd: /* optional */ {
1.7 zhuk 164: $$.cmd = NULL;
165: $$.cmdargs = NULL;
166: } | TCMD TSTRING args {
167: $$.cmd = $2.str;
168: $$.cmdargs = $3.cmdargs;
169: } ;
170:
171: args: /* empty */ {
172: $$.cmdargs = NULL;
173: } | TARGS argslist {
174: $$.cmdargs = $2.cmdargs;
175: } ;
176:
177: argslist: /* empty */ {
178: if (!($$.cmdargs = calloc(1, sizeof(char *))))
179: errx(1, "can't allocate args");
180: } | argslist TSTRING {
181: int nargs = arraylen($1.cmdargs);
1.11 deraadt 182: if (!($$.cmdargs = reallocarray($1.cmdargs, nargs + 2,
183: sizeof(char *))))
1.7 zhuk 184: errx(1, "can't allocate args");
185: $$.cmdargs[nargs] = $2.str;
186: $$.cmdargs[nargs + 1] = NULL;
1.1 tedu 187: } ;
188:
189: %%
190:
191: void
192: yyerror(const char *fmt, ...)
193: {
194: va_list va;
195:
1.15 gsoares 196: fprintf(stderr, "doas: ");
1.1 tedu 197: va_start(va, fmt);
1.10 zhuk 198: vfprintf(stderr, fmt, va);
199: va_end(va);
200: fprintf(stderr, " at line %d\n", yylval.lineno + 1);
201: parse_errors++;
1.1 tedu 202: }
203:
204: struct keyword {
205: const char *word;
206: int token;
207: } keywords[] = {
208: { "deny", TDENY },
209: { "permit", TPERMIT },
210: { "as", TAS },
211: { "cmd", TCMD },
1.7 zhuk 212: { "args", TARGS },
1.1 tedu 213: { "nopass", TNOPASS },
214: { "keepenv", TKEEPENV },
215: };
216:
217: int
218: yylex(void)
219: {
220: char buf[1024], *ebuf, *p, *str;
1.10 zhuk 221: int i, c, quotes = 0, escape = 0, qpos = -1, nonkw = 0;
1.1 tedu 222:
223: p = buf;
224: ebuf = buf + sizeof(buf);
1.9 zhuk 225:
1.5 benno 226: repeat:
1.9 zhuk 227: /* skip whitespace first */
228: for (c = getc(yyfp); c == ' ' || c == '\t'; c = getc(yyfp))
1.10 zhuk 229: yylval.colno++;
1.9 zhuk 230:
231: /* check for special one-character constructions */
1.1 tedu 232: switch (c) {
1.9 zhuk 233: case '\n':
1.10 zhuk 234: yylval.colno = 0;
235: yylval.lineno++;
1.9 zhuk 236: /* FALLTHROUGH */
237: case '{':
238: case '}':
1.16 djm 239: case '=':
1.9 zhuk 240: return c;
241: case '#':
242: /* skip comments; NUL is allowed; no continuation */
243: while ((c = getc(yyfp)) != '\n')
244: if (c == EOF)
1.14 tedu 245: goto eof;
1.10 zhuk 246: yylval.colno = 0;
247: yylval.lineno++;
1.9 zhuk 248: return c;
249: case EOF:
1.14 tedu 250: goto eof;
1.1 tedu 251: }
1.9 zhuk 252:
253: /* parsing next word */
1.10 zhuk 254: for (;; c = getc(yyfp), yylval.colno++) {
1.3 zhuk 255: switch (c) {
1.9 zhuk 256: case '\0':
1.11 deraadt 257: yyerror("unallowed character NUL in column %d",
258: yylval.colno + 1);
1.9 zhuk 259: escape = 0;
260: continue;
261: case '\\':
262: escape = !escape;
263: if (escape)
264: continue;
265: break;
1.3 zhuk 266: case '\n':
1.9 zhuk 267: if (quotes)
1.10 zhuk 268: yyerror("unterminated quotes in column %d",
269: qpos + 1);
1.9 zhuk 270: if (escape) {
271: nonkw = 1;
272: escape = 0;
1.12 mikeb 273: yylval.colno = 0;
274: yylval.lineno++;
1.9 zhuk 275: continue;
276: }
277: goto eow;
278: case EOF:
279: if (escape)
1.10 zhuk 280: yyerror("unterminated escape in column %d",
281: yylval.colno);
1.9 zhuk 282: if (quotes)
1.10 zhuk 283: yyerror("unterminated quotes in column %d",
284: qpos + 1);
285: goto eow;
1.9 zhuk 286: /* FALLTHROUGH */
1.3 zhuk 287: case '{':
288: case '}':
289: case '#':
290: case ' ':
291: case '\t':
1.16 djm 292: case '=':
1.9 zhuk 293: if (!escape && !quotes)
294: goto eow;
295: break;
296: case '"':
297: if (!escape) {
298: quotes = !quotes;
299: if (quotes) {
300: nonkw = 1;
1.10 zhuk 301: qpos = yylval.colno;
1.9 zhuk 302: }
303: continue;
304: }
1.3 zhuk 305: }
1.1 tedu 306: *p++ = c;
1.13 tedu 307: if (p == ebuf) {
1.10 zhuk 308: yyerror("too long line");
1.13 tedu 309: p = buf;
310: }
1.9 zhuk 311: escape = 0;
1.1 tedu 312: }
1.9 zhuk 313:
1.3 zhuk 314: eow:
1.1 tedu 315: *p = 0;
316: if (c != EOF)
317: ungetc(c, yyfp);
1.9 zhuk 318: if (p == buf) {
319: /*
1.11 deraadt 320: * There could be a number of reasons for empty buffer,
321: * and we handle all of them here, to avoid cluttering
322: * the main loop.
1.9 zhuk 323: */
324: if (c == EOF)
1.14 tedu 325: goto eof;
1.10 zhuk 326: else if (qpos == -1) /* accept, e.g., empty args: cmd foo args "" */
1.9 zhuk 327: goto repeat;
328: }
329: if (!nonkw) {
330: for (i = 0; i < sizeof(keywords) / sizeof(keywords[0]); i++) {
331: if (strcmp(buf, keywords[i].word) == 0)
332: return keywords[i].token;
333: }
1.1 tedu 334: }
335: if ((str = strdup(buf)) == NULL)
336: err(1, "strdup");
337: yylval.str = str;
338: return TSTRING;
1.14 tedu 339:
340: eof:
341: if (ferror(yyfp))
342: yyerror("input error reading config");
343: return 0;
1.1 tedu 344: }