xref: /freebsd/contrib/libarchive/cpio/cmdline.c (revision b2d2a78ad80ec68d4a17f5aef97d21686cb1e29b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2003-2007 Tim Kientzle
5  * All rights reserved.
6  */
7 
8 
9 #include "cpio_platform.h"
10 
11 #ifdef HAVE_ERRNO_H
12 #include <errno.h>
13 #endif
14 #ifdef HAVE_GRP_H
15 #include <grp.h>
16 #endif
17 #ifdef HAVE_PWD_H
18 #include <pwd.h>
19 #endif
20 #include <stdio.h>
21 #ifdef HAVE_STDLIB_H
22 #include <stdlib.h>
23 #endif
24 #ifdef HAVE_STRING_H
25 #include <string.h>
26 #endif
27 
28 #include "cpio.h"
29 #include "err.h"
30 
31 /*
32  * Short options for cpio.  Please keep this sorted.
33  */
34 static const char *short_options = "067AaBC:cdE:F:f:H:hI:iJjLlmnO:opR:rtuVvW:yZz";
35 
36 /*
37  * Long options for cpio.  Please keep this sorted.
38  */
39 static const struct option {
40 	const char *name;
41 	int required;	/* 1 if this option requires an argument */
42 	int equivalent;	/* Equivalent short option. */
43 } cpio_longopts[] = {
44 	{ "b64encode",			0, OPTION_B64ENCODE },
45 	{ "binary",			0, '7' },
46 	{ "create",			0, 'o' },
47 	{ "dereference",		0, 'L' },
48 	{ "dot",			0, 'V' },
49 	{ "extract",			0, 'i' },
50 	{ "file",			1, 'F' },
51 	{ "format",             	1, 'H' },
52 	{ "grzip",			0, OPTION_GRZIP },
53 	{ "help",			0, 'h' },
54 	{ "insecure",			0, OPTION_INSECURE },
55 	{ "link",			0, 'l' },
56 	{ "list",			0, 't' },
57 	{ "lrzip",			0, OPTION_LRZIP },
58 	{ "lz4",			0, OPTION_LZ4 },
59 	{ "lzma",			0, OPTION_LZMA },
60 	{ "lzop",			0, OPTION_LZOP },
61 	{ "make-directories",		0, 'd' },
62 	{ "no-preserve-owner",		0, OPTION_NO_PRESERVE_OWNER },
63 	{ "null",			0, '0' },
64 	{ "numeric-uid-gid",		0, 'n' },
65 	{ "owner",			1, 'R' },
66 	{ "passphrase",			1, OPTION_PASSPHRASE },
67 	{ "pass-through",		0, 'p' },
68 	{ "preserve-modification-time", 0, 'm' },
69 	{ "preserve-owner",		0, OPTION_PRESERVE_OWNER },
70 	{ "pwb",			0, '6' },
71 	{ "quiet",			0, OPTION_QUIET },
72 	{ "unconditional",		0, 'u' },
73 	{ "uuencode",			0, OPTION_UUENCODE },
74 	{ "verbose",			0, 'v' },
75 	{ "version",			0, OPTION_VERSION },
76 	{ "xz",				0, 'J' },
77 	{ "zstd",			0, OPTION_ZSTD },
78 	{ NULL, 0, 0 }
79 };
80 
81 /*
82  * I used to try to select platform-provided getopt() or
83  * getopt_long(), but that caused a lot of headaches.  In particular,
84  * I couldn't consistently use long options in the test harness
85  * because not all platforms have getopt_long().  That in turn led to
86  * overuse of the -W hack in the test harness, which made it rough to
87  * run the test harness against GNU cpio.  (I periodically run the
88  * test harness here against GNU cpio as a sanity-check.  Yes,
89  * I've found a couple of bugs in GNU cpio that way.)
90  */
91 int
92 cpio_getopt(struct cpio *cpio)
93 {
94 	enum { state_start = 0, state_next_word, state_short, state_long };
95 	static int state = state_start;
96 	static char *opt_word;
97 
98 	const struct option *popt, *match, *match2;
99 	const char *p, *long_prefix;
100 	size_t optlength;
101 	int opt;
102 	int required;
103 
104 again:
105 	match = NULL;
106 	match2 = NULL;
107 	long_prefix = "--";
108 	opt = '?';
109 	required = 0;
110 	cpio->argument = NULL;
111 
112 	/* First time through, initialize everything. */
113 	if (state == state_start) {
114 		/* Skip program name. */
115 		++cpio->argv;
116 		--cpio->argc;
117 		state = state_next_word;
118 	}
119 
120 	/*
121 	 * We're ready to look at the next word in argv.
122 	 */
123 	if (state == state_next_word) {
124 		/* No more arguments, so no more options. */
125 		if (cpio->argv[0] == NULL)
126 			return (-1);
127 		/* Doesn't start with '-', so no more options. */
128 		if (cpio->argv[0][0] != '-')
129 			return (-1);
130 		/* "--" marks end of options; consume it and return. */
131 		if (strcmp(cpio->argv[0], "--") == 0) {
132 			++cpio->argv;
133 			--cpio->argc;
134 			return (-1);
135 		}
136 		/* Get next word for parsing. */
137 		opt_word = *cpio->argv++;
138 		--cpio->argc;
139 		if (opt_word[1] == '-') {
140 			/* Set up long option parser. */
141 			state = state_long;
142 			opt_word += 2; /* Skip leading '--' */
143 		} else {
144 			/* Set up short option parser. */
145 			state = state_short;
146 			++opt_word;  /* Skip leading '-' */
147 		}
148 	}
149 
150 	/*
151 	 * We're parsing a group of POSIX-style single-character options.
152 	 */
153 	if (state == state_short) {
154 		/* Peel next option off of a group of short options. */
155 		opt = *opt_word++;
156 		if (opt == '\0') {
157 			/* End of this group; recurse to get next option. */
158 			state = state_next_word;
159 			goto again;
160 		}
161 
162 		/* Does this option take an argument? */
163 		p = strchr(short_options, opt);
164 		if (p == NULL)
165 			return ('?');
166 		if (p[1] == ':')
167 			required = 1;
168 
169 		/* If it takes an argument, parse that. */
170 		if (required) {
171 			/* If arg is run-in, opt_word already points to it. */
172 			if (opt_word[0] == '\0') {
173 				/* Otherwise, pick up the next word. */
174 				opt_word = *cpio->argv;
175 				if (opt_word == NULL) {
176 					lafe_warnc(0,
177 					    "Option -%c requires an argument",
178 					    opt);
179 					return ('?');
180 				}
181 				++cpio->argv;
182 				--cpio->argc;
183 			}
184 			if (opt == 'W') {
185 				state = state_long;
186 				long_prefix = "-W "; /* For clearer errors. */
187 			} else {
188 				state = state_next_word;
189 				cpio->argument = opt_word;
190 			}
191 		}
192 	}
193 
194 	/* We're reading a long option, including -W long=arg convention. */
195 	if (state == state_long) {
196 		/* After this long option, we'll be starting a new word. */
197 		state = state_next_word;
198 
199 		/* Option name ends at '=' if there is one. */
200 		p = strchr(opt_word, '=');
201 		if (p != NULL) {
202 			optlength = (size_t)(p - opt_word);
203 			cpio->argument = (char *)(uintptr_t)(p + 1);
204 		} else {
205 			optlength = strlen(opt_word);
206 		}
207 
208 		/* Search the table for an unambiguous match. */
209 		for (popt = cpio_longopts; popt->name != NULL; popt++) {
210 			/* Short-circuit if first chars don't match. */
211 			if (popt->name[0] != opt_word[0])
212 				continue;
213 			/* If option is a prefix of name in table, record it.*/
214 			if (strncmp(opt_word, popt->name, optlength) == 0) {
215 				match2 = match; /* Record up to two matches. */
216 				match = popt;
217 				/* If it's an exact match, we're done. */
218 				if (strlen(popt->name) == optlength) {
219 					match2 = NULL; /* Forget the others. */
220 					break;
221 				}
222 			}
223 		}
224 
225 		/* Fail if there wasn't a unique match. */
226 		if (match == NULL) {
227 			lafe_warnc(0,
228 			    "Option %s%s is not supported",
229 			    long_prefix, opt_word);
230 			return ('?');
231 		}
232 		if (match2 != NULL) {
233 			lafe_warnc(0,
234 			    "Ambiguous option %s%s (matches --%s and --%s)",
235 			    long_prefix, opt_word, match->name, match2->name);
236 			return ('?');
237 		}
238 
239 		/* We've found a unique match; does it need an argument? */
240 		if (match->required) {
241 			/* Argument required: get next word if necessary. */
242 			if (cpio->argument == NULL) {
243 				cpio->argument = *cpio->argv;
244 				if (cpio->argument == NULL) {
245 					lafe_warnc(0,
246 					    "Option %s%s requires an argument",
247 					    long_prefix, match->name);
248 					return ('?');
249 				}
250 				++cpio->argv;
251 				--cpio->argc;
252 			}
253 		} else {
254 			/* Argument forbidden: fail if there is one. */
255 			if (cpio->argument != NULL) {
256 				lafe_warnc(0,
257 				    "Option %s%s does not allow an argument",
258 				    long_prefix, match->name);
259 				return ('?');
260 			}
261 		}
262 		return (match->equivalent);
263 	}
264 
265 	return (opt);
266 }
267 
268 
269 /*
270  * Parse the argument to the -R or --owner flag.
271  *
272  * The format is one of the following:
273  *   <username|uid>    - Override user but not group
274  *   <username>:   - Override both, group is user's default group
275  *   <uid>:    - Override user but not group
276  *   <username|uid>:<groupname|gid> - Override both
277  *   :<groupname|gid>  - Override group but not user
278  *
279  * Where uid/gid are decimal representations and groupname/username
280  * are names to be looked up in system database.  Note that we try
281  * to look up an argument as a name first, then try numeric parsing.
282  *
283  * A period can be used instead of the colon.
284  *
285  * Sets uid/gid return as appropriate, -1 indicates uid/gid not specified.
286  * TODO: If the spec uses uname/gname, then return those to the caller
287  * as well.  If the spec provides uid/gid, just return names as NULL.
288  *
289  * Returns NULL if no error, otherwise returns error string for display.
290  *
291  */
292 int
293 owner_parse(const char *spec, struct cpio_owner *owner, const char **errmsg)
294 {
295 	static char errbuff[128];
296 	const char *u, *ue, *g;
297 
298 	owner->uid = -1;
299 	owner->gid = -1;
300 
301 	owner->uname = NULL;
302 	owner->gname = NULL;
303 
304 	if (spec[0] == '\0') {
305 		*errmsg = "Invalid empty user/group spec";
306 		return (-1);
307 	}
308 
309 	/*
310 	 * Split spec into [user][:.][group]
311 	 *  u -> first char of username, NULL if no username
312 	 *  ue -> first char after username (colon, period, or \0)
313 	 *  g -> first char of group name
314 	 */
315 	if (*spec == ':' || *spec == '.') {
316 		/* If spec starts with ':' or '.', then just group. */
317 		ue = u = NULL;
318 		g = spec + 1;
319 	} else {
320 		/* Otherwise, [user] or [user][:] or [user][:][group] */
321 		ue = u = spec;
322 		while (*ue != ':' && *ue != '.' && *ue != '\0')
323 			++ue;
324 		g = ue;
325 		if (*g != '\0') /* Skip : or . to find first char of group. */
326 			++g;
327 	}
328 
329 	if (u != NULL) {
330 		/* Look up user: ue is first char after end of user. */
331 		char *user;
332 		struct passwd *pwent;
333 
334 		user = malloc(ue - u + 1);
335 		if (user == NULL)
336 			goto alloc_error;
337 		memcpy(user, u, ue - u);
338 		user[ue - u] = '\0';
339 		if ((pwent = getpwnam(user)) != NULL) {
340 			owner->uid = pwent->pw_uid;
341 			owner->uname = strdup(pwent->pw_name);
342 			if (owner->uname == NULL) {
343 				free(user);
344 				goto alloc_error;
345 			}
346 			if (*ue != '\0')
347 				owner->gid = pwent->pw_gid;
348 		} else {
349 			char *end;
350 			errno = 0;
351 			owner->uid = (int)strtoul(user, &end, 10);
352 			if (errno || *end != '\0') {
353 				snprintf(errbuff, sizeof(errbuff),
354 				    "Couldn't lookup user ``%s''", user);
355 				errbuff[sizeof(errbuff) - 1] = '\0';
356 				free(user);
357 				*errmsg = errbuff;
358 				return (-1);
359 			}
360 		}
361 		free(user);
362 	}
363 
364 	if (*g != '\0') {
365 		struct group *grp;
366 		if ((grp = getgrnam(g)) != NULL) {
367 			owner->gid = grp->gr_gid;
368 			owner->gname = strdup(grp->gr_name);
369 			if (owner->gname == NULL) {
370 				free(owner->uname);
371 				owner->uname = NULL;
372 				goto alloc_error;
373 			}
374 		} else {
375 			char *end;
376 			errno = 0;
377 			owner->gid = (int)strtoul(g, &end, 10);
378 			if (errno || *end != '\0') {
379 				snprintf(errbuff, sizeof(errbuff),
380 				    "Couldn't lookup group ``%s''", g);
381 				errbuff[sizeof(errbuff) - 1] = '\0';
382 				*errmsg = errbuff;
383 				return (-1);
384 			}
385 		}
386 	}
387 	return (0);
388 alloc_error:
389 	*errmsg = "Couldn't allocate memory";
390 	return (-1);
391 }
392