Annotation of src/usr.bin/doas/parse.y, Revision 1.12
1.12 ! mikeb 1: /* $OpenBSD: parse.y,v 1.11 2015/07/28 21:36:03 deraadt 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
1.1 tedu 59: %token TNOPASS TKEEPENV
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: } ;
114: option: TNOPASS {
115: $$.options = NOPASS;
116: } | TKEEPENV {
117: $$.options = KEEPENV;
118: } | TKEEPENV '{' envlist '}' {
119: $$.options = KEEPENV;
120: $$.envlist = $3.envlist;
121: } ;
122:
123: envlist: /* empty */ {
124: if (!($$.envlist = calloc(1, sizeof(char *))))
125: errx(1, "can't allocate envlist");
126: } | envlist TSTRING {
127: int nenv = arraylen($1.envlist);
1.6 benno 128: if (!($$.envlist = reallocarray($1.envlist, nenv + 2,
129: sizeof(char *))))
1.1 tedu 130: errx(1, "can't allocate envlist");
131: $$.envlist[nenv] = $2.str;
132: $$.envlist[nenv + 1] = NULL;
133: }
134:
135:
136: ident: TSTRING {
137: $$.str = $1.str;
138: } ;
139:
140: target: /* optional */ {
141: $$.str = NULL;
142: } | TAS TSTRING {
143: $$.str = $2.str;
144: } ;
145:
146: cmd: /* optional */ {
1.7 zhuk 147: $$.cmd = NULL;
148: $$.cmdargs = NULL;
149: } | TCMD TSTRING args {
150: $$.cmd = $2.str;
151: $$.cmdargs = $3.cmdargs;
152: } ;
153:
154: args: /* empty */ {
155: $$.cmdargs = NULL;
156: } | TARGS argslist {
157: $$.cmdargs = $2.cmdargs;
158: } ;
159:
160: argslist: /* empty */ {
161: if (!($$.cmdargs = calloc(1, sizeof(char *))))
162: errx(1, "can't allocate args");
163: } | argslist TSTRING {
164: int nargs = arraylen($1.cmdargs);
1.11 deraadt 165: if (!($$.cmdargs = reallocarray($1.cmdargs, nargs + 2,
166: sizeof(char *))))
1.7 zhuk 167: errx(1, "can't allocate args");
168: $$.cmdargs[nargs] = $2.str;
169: $$.cmdargs[nargs + 1] = NULL;
1.1 tedu 170: } ;
171:
172: %%
173:
174: void
175: yyerror(const char *fmt, ...)
176: {
177: va_list va;
178:
179: va_start(va, fmt);
1.10 zhuk 180: vfprintf(stderr, fmt, va);
181: va_end(va);
182: fprintf(stderr, " at line %d\n", yylval.lineno + 1);
183: parse_errors++;
1.1 tedu 184: }
185:
186: struct keyword {
187: const char *word;
188: int token;
189: } keywords[] = {
190: { "deny", TDENY },
191: { "permit", TPERMIT },
192: { "as", TAS },
193: { "cmd", TCMD },
1.7 zhuk 194: { "args", TARGS },
1.1 tedu 195: { "nopass", TNOPASS },
196: { "keepenv", TKEEPENV },
197: };
198:
199: int
200: yylex(void)
201: {
202: char buf[1024], *ebuf, *p, *str;
1.10 zhuk 203: int i, c, quotes = 0, escape = 0, qpos = -1, nonkw = 0;
1.1 tedu 204:
205: p = buf;
206: ebuf = buf + sizeof(buf);
1.9 zhuk 207:
1.5 benno 208: repeat:
1.9 zhuk 209: /* skip whitespace first */
210: for (c = getc(yyfp); c == ' ' || c == '\t'; c = getc(yyfp))
1.10 zhuk 211: yylval.colno++;
1.9 zhuk 212:
213: /* check for special one-character constructions */
1.1 tedu 214: switch (c) {
1.9 zhuk 215: case '\n':
1.10 zhuk 216: yylval.colno = 0;
217: yylval.lineno++;
1.9 zhuk 218: /* FALLTHROUGH */
219: case '{':
220: case '}':
221: return c;
222: case '#':
223: /* skip comments; NUL is allowed; no continuation */
224: while ((c = getc(yyfp)) != '\n')
225: if (c == EOF)
226: return 0;
1.10 zhuk 227: yylval.colno = 0;
228: yylval.lineno++;
1.9 zhuk 229: return c;
230: case EOF:
1.1 tedu 231: return 0;
232: }
1.9 zhuk 233:
234: /* parsing next word */
1.10 zhuk 235: for (;; c = getc(yyfp), yylval.colno++) {
1.3 zhuk 236: switch (c) {
1.9 zhuk 237: case '\0':
1.11 deraadt 238: yyerror("unallowed character NUL in column %d",
239: yylval.colno + 1);
1.9 zhuk 240: escape = 0;
241: continue;
242: case '\\':
243: escape = !escape;
244: if (escape)
245: continue;
246: break;
1.3 zhuk 247: case '\n':
1.9 zhuk 248: if (quotes)
1.10 zhuk 249: yyerror("unterminated quotes in column %d",
250: qpos + 1);
1.9 zhuk 251: if (escape) {
252: nonkw = 1;
253: escape = 0;
1.12 ! mikeb 254: yylval.colno = 0;
! 255: yylval.lineno++;
1.9 zhuk 256: continue;
257: }
258: goto eow;
259: case EOF:
260: if (escape)
1.10 zhuk 261: yyerror("unterminated escape in column %d",
262: yylval.colno);
1.9 zhuk 263: if (quotes)
1.10 zhuk 264: yyerror("unterminated quotes in column %d",
265: qpos + 1);
266: goto eow;
1.9 zhuk 267: /* FALLTHROUGH */
1.3 zhuk 268: case '{':
269: case '}':
270: case '#':
271: case ' ':
272: case '\t':
1.9 zhuk 273: if (!escape && !quotes)
274: goto eow;
275: break;
276: case '"':
277: if (!escape) {
278: quotes = !quotes;
279: if (quotes) {
280: nonkw = 1;
1.10 zhuk 281: qpos = yylval.colno;
1.9 zhuk 282: }
283: continue;
284: }
1.3 zhuk 285: }
1.1 tedu 286: *p++ = c;
287: if (p == ebuf)
1.10 zhuk 288: yyerror("too long line");
1.9 zhuk 289: escape = 0;
1.1 tedu 290: }
1.9 zhuk 291:
1.3 zhuk 292: eow:
1.1 tedu 293: *p = 0;
294: if (c != EOF)
295: ungetc(c, yyfp);
1.9 zhuk 296: if (p == buf) {
297: /*
1.11 deraadt 298: * There could be a number of reasons for empty buffer,
299: * and we handle all of them here, to avoid cluttering
300: * the main loop.
1.9 zhuk 301: */
302: if (c == EOF)
303: return 0;
1.10 zhuk 304: else if (qpos == -1) /* accept, e.g., empty args: cmd foo args "" */
1.9 zhuk 305: goto repeat;
306: }
307: if (!nonkw) {
308: for (i = 0; i < sizeof(keywords) / sizeof(keywords[0]); i++) {
309: if (strcmp(buf, keywords[i].word) == 0)
310: return keywords[i].token;
311: }
1.1 tedu 312: }
313: if ((str = strdup(buf)) == NULL)
314: err(1, "strdup");
315: yylval.str = str;
316: return TSTRING;
317: }