xref: /freebsd/contrib/libarchive/cpio/cmdline.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
1 /*-
2  * Copyright (c) 2003-2007 Tim Kientzle
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 
28 #include "cpio_platform.h"
29 __FBSDID("$FreeBSD$");
30 
31 #ifdef HAVE_ERRNO_H
32 #include <errno.h>
33 #endif
34 #ifdef HAVE_GRP_H
35 #include <grp.h>
36 #endif
37 #ifdef HAVE_PWD_H
38 #include <pwd.h>
39 #endif
40 #include <stdio.h>
41 #ifdef HAVE_STDLIB_H
42 #include <stdlib.h>
43 #endif
44 #ifdef HAVE_STRING_H
45 #include <string.h>
46 #endif
47 
48 #include "cpio.h"
49 #include "err.h"
50 
51 /*
52  * Short options for cpio.  Please keep this sorted.
53  */
54 static const char *short_options = "0AaBC:cdE:F:f:H:hI:iJjLlmnO:opR:rtuvW:yZz";
55 
56 /*
57  * Long options for cpio.  Please keep this sorted.
58  */
59 static const struct option {
60 	const char *name;
61 	int required;	/* 1 if this option requires an argument */
62 	int equivalent;	/* Equivalent short option. */
63 } cpio_longopts[] = {
64 	{ "create",			0, 'o' },
65 	{ "extract",			0, 'i' },
66 	{ "file",			1, 'F' },
67 	{ "format",             	1, 'H' },
68 	{ "help",			0, 'h' },
69 	{ "insecure",			0, OPTION_INSECURE },
70 	{ "link",			0, 'l' },
71 	{ "list",			0, 't' },
72 	{ "lzma",			0, OPTION_LZMA },
73 	{ "make-directories",		0, 'd' },
74 	{ "no-preserve-owner",		0, OPTION_NO_PRESERVE_OWNER },
75 	{ "null",			0, '0' },
76 	{ "numeric-uid-gid",		0, 'n' },
77 	{ "owner",			1, 'R' },
78 	{ "pass-through",		0, 'p' },
79 	{ "preserve-modification-time", 0, 'm' },
80 	{ "preserve-owner",		0, OPTION_PRESERVE_OWNER },
81 	{ "quiet",			0, OPTION_QUIET },
82 	{ "unconditional",		0, 'u' },
83 	{ "verbose",			0, 'v' },
84 	{ "version",			0, OPTION_VERSION },
85 	{ "xz",				0, 'J' },
86 	{ NULL, 0, 0 }
87 };
88 
89 /*
90  * I used to try to select platform-provided getopt() or
91  * getopt_long(), but that caused a lot of headaches.  In particular,
92  * I couldn't consistently use long options in the test harness
93  * because not all platforms have getopt_long().  That in turn led to
94  * overuse of the -W hack in the test harness, which made it rough to
95  * run the test harness against GNU cpio.  (I periodically run the
96  * test harness here against GNU cpio as a sanity-check.  Yes,
97  * I've found a couple of bugs in GNU cpio that way.)
98  */
99 int
100 cpio_getopt(struct cpio *cpio)
101 {
102 	enum { state_start = 0, state_next_word, state_short, state_long };
103 	static int state = state_start;
104 	static char *opt_word;
105 
106 	const struct option *popt, *match = NULL, *match2 = NULL;
107 	const char *p, *long_prefix = "--";
108 	size_t optlength;
109 	int opt = '?';
110 	int required = 0;
111 
112 	cpio->optarg = NULL;
113 
114 	/* First time through, initialize everything. */
115 	if (state == state_start) {
116 		/* Skip program name. */
117 		++cpio->argv;
118 		--cpio->argc;
119 		state = state_next_word;
120 	}
121 
122 	/*
123 	 * We're ready to look at the next word in argv.
124 	 */
125 	if (state == state_next_word) {
126 		/* No more arguments, so no more options. */
127 		if (cpio->argv[0] == NULL)
128 			return (-1);
129 		/* Doesn't start with '-', so no more options. */
130 		if (cpio->argv[0][0] != '-')
131 			return (-1);
132 		/* "--" marks end of options; consume it and return. */
133 		if (strcmp(cpio->argv[0], "--") == 0) {
134 			++cpio->argv;
135 			--cpio->argc;
136 			return (-1);
137 		}
138 		/* Get next word for parsing. */
139 		opt_word = *cpio->argv++;
140 		--cpio->argc;
141 		if (opt_word[1] == '-') {
142 			/* Set up long option parser. */
143 			state = state_long;
144 			opt_word += 2; /* Skip leading '--' */
145 		} else {
146 			/* Set up short option parser. */
147 			state = state_short;
148 			++opt_word;  /* Skip leading '-' */
149 		}
150 	}
151 
152 	/*
153 	 * We're parsing a group of POSIX-style single-character options.
154 	 */
155 	if (state == state_short) {
156 		/* Peel next option off of a group of short options. */
157 		opt = *opt_word++;
158 		if (opt == '\0') {
159 			/* End of this group; recurse to get next option. */
160 			state = state_next_word;
161 			return cpio_getopt(cpio);
162 		}
163 
164 		/* Does this option take an argument? */
165 		p = strchr(short_options, opt);
166 		if (p == NULL)
167 			return ('?');
168 		if (p[1] == ':')
169 			required = 1;
170 
171 		/* If it takes an argument, parse that. */
172 		if (required) {
173 			/* If arg is run-in, opt_word already points to it. */
174 			if (opt_word[0] == '\0') {
175 				/* Otherwise, pick up the next word. */
176 				opt_word = *cpio->argv;
177 				if (opt_word == NULL) {
178 					lafe_warnc(0,
179 					    "Option -%c requires an argument",
180 					    opt);
181 					return ('?');
182 				}
183 				++cpio->argv;
184 				--cpio->argc;
185 			}
186 			if (opt == 'W') {
187 				state = state_long;
188 				long_prefix = "-W "; /* For clearer errors. */
189 			} else {
190 				state = state_next_word;
191 				cpio->optarg = opt_word;
192 			}
193 		}
194 	}
195 
196 	/* We're reading a long option, including -W long=arg convention. */
197 	if (state == state_long) {
198 		/* After this long option, we'll be starting a new word. */
199 		state = state_next_word;
200 
201 		/* Option name ends at '=' if there is one. */
202 		p = strchr(opt_word, '=');
203 		if (p != NULL) {
204 			optlength = (size_t)(p - opt_word);
205 			cpio->optarg = (char *)(uintptr_t)(p + 1);
206 		} else {
207 			optlength = strlen(opt_word);
208 		}
209 
210 		/* Search the table for an unambiguous match. */
211 		for (popt = cpio_longopts; popt->name != NULL; popt++) {
212 			/* Short-circuit if first chars don't match. */
213 			if (popt->name[0] != opt_word[0])
214 				continue;
215 			/* If option is a prefix of name in table, record it.*/
216 			if (strncmp(opt_word, popt->name, optlength) == 0) {
217 				match2 = match; /* Record up to two matches. */
218 				match = popt;
219 				/* If it's an exact match, we're done. */
220 				if (strlen(popt->name) == optlength) {
221 					match2 = NULL; /* Forget the others. */
222 					break;
223 				}
224 			}
225 		}
226 
227 		/* Fail if there wasn't a unique match. */
228 		if (match == NULL) {
229 			lafe_warnc(0,
230 			    "Option %s%s is not supported",
231 			    long_prefix, opt_word);
232 			return ('?');
233 		}
234 		if (match2 != NULL) {
235 			lafe_warnc(0,
236 			    "Ambiguous option %s%s (matches --%s and --%s)",
237 			    long_prefix, opt_word, match->name, match2->name);
238 			return ('?');
239 		}
240 
241 		/* We've found a unique match; does it need an argument? */
242 		if (match->required) {
243 			/* Argument required: get next word if necessary. */
244 			if (cpio->optarg == NULL) {
245 				cpio->optarg = *cpio->argv;
246 				if (cpio->optarg == NULL) {
247 					lafe_warnc(0,
248 					    "Option %s%s requires an argument",
249 					    long_prefix, match->name);
250 					return ('?');
251 				}
252 				++cpio->argv;
253 				--cpio->argc;
254 			}
255 		} else {
256 			/* Argument forbidden: fail if there is one. */
257 			if (cpio->optarg != NULL) {
258 				lafe_warnc(0,
259 				    "Option %s%s does not allow an argument",
260 				    long_prefix, match->name);
261 				return ('?');
262 			}
263 		}
264 		return (match->equivalent);
265 	}
266 
267 	return (opt);
268 }
269 
270 
271 /*
272  * Parse the argument to the -R or --owner flag.
273  *
274  * The format is one of the following:
275  *   <username|uid>    - Override user but not group
276  *   <username>:   - Override both, group is user's default group
277  *   <uid>:    - Override user but not group
278  *   <username|uid>:<groupname|gid> - Override both
279  *   :<groupname|gid>  - Override group but not user
280  *
281  * Where uid/gid are decimal representations and groupname/username
282  * are names to be looked up in system database.  Note that we try
283  * to look up an argument as a name first, then try numeric parsing.
284  *
285  * A period can be used instead of the colon.
286  *
287  * Sets uid/gid return as appropriate, -1 indicates uid/gid not specified.
288  * TODO: If the spec uses uname/gname, then return those to the caller
289  * as well.  If the spec provides uid/gid, just return names as NULL.
290  *
291  * Returns NULL if no error, otherwise returns error string for display.
292  *
293  */
294 const char *
295 owner_parse(const char *spec, int *uid, int *gid)
296 {
297 	static char errbuff[128];
298 	const char *u, *ue, *g;
299 
300 	*uid = -1;
301 	*gid = -1;
302 
303 	if (spec[0] == '\0')
304 		return ("Invalid empty user/group spec");
305 
306 	/*
307 	 * Split spec into [user][:.][group]
308 	 *  u -> first char of username, NULL if no username
309 	 *  ue -> first char after username (colon, period, or \0)
310 	 *  g -> first char of group name
311 	 */
312 	if (*spec == ':' || *spec == '.') {
313 		/* If spec starts with ':' or '.', then just group. */
314 		ue = u = NULL;
315 		g = spec + 1;
316 	} else {
317 		/* Otherwise, [user] or [user][:] or [user][:][group] */
318 		ue = u = spec;
319 		while (*ue != ':' && *ue != '.' && *ue != '\0')
320 			++ue;
321 		g = ue;
322 		if (*g != '\0') /* Skip : or . to find first char of group. */
323 			++g;
324 	}
325 
326 	if (u != NULL) {
327 		/* Look up user: ue is first char after end of user. */
328 		char *user;
329 		struct passwd *pwent;
330 
331 		user = (char *)malloc(ue - u + 1);
332 		if (user == NULL)
333 			return ("Couldn't allocate memory");
334 		memcpy(user, u, ue - u);
335 		user[ue - u] = '\0';
336 		if ((pwent = getpwnam(user)) != NULL) {
337 			*uid = pwent->pw_uid;
338 			if (*ue != '\0')
339 				*gid = pwent->pw_gid;
340 		} else {
341 			char *end;
342 			errno = 0;
343 			*uid = strtoul(user, &end, 10);
344 			if (errno || *end != '\0') {
345 				snprintf(errbuff, sizeof(errbuff),
346 				    "Couldn't lookup user ``%s''", user);
347 				errbuff[sizeof(errbuff) - 1] = '\0';
348 				return (errbuff);
349 			}
350 		}
351 		free(user);
352 	}
353 
354 	if (*g != '\0') {
355 		struct group *grp;
356 		if ((grp = getgrnam(g)) != NULL) {
357 			*gid = grp->gr_gid;
358 		} else {
359 			char *end;
360 			errno = 0;
361 			*gid = strtoul(g, &end, 10);
362 			if (errno || *end != '\0') {
363 				snprintf(errbuff, sizeof(errbuff),
364 				    "Couldn't lookup group ``%s''", g);
365 				errbuff[sizeof(errbuff) - 1] = '\0';
366 				return (errbuff);
367 			}
368 		}
369 	}
370 	return (NULL);
371 }
372