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