/*-

 * Copyright (c) 2003-2007 Tim Kientzle

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer

 *    in this position and unchanged.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "cpio_platform.h"

__FBSDID("$FreeBSD: src/usr.bin/cpio/cmdline.c,v 1.5 2008/12/06 07:30:40 kientzle Exp $");

#ifdef HAVE_ERRNO_H

#include <errno.h>

#endif

#ifdef HAVE_GRP_H

#include <grp.h>

#endif

#ifdef HAVE_PWD_H

#include <pwd.h>

#endif

#include <stdio.h>

#ifdef HAVE_STDLIB_H

#include <stdlib.h>

#endif

#ifdef HAVE_STRING_H

#include <string.h>

#endif

#include "cpio.h"

#include "err.h"

/*

 * Short options for cpio.  Please keep this sorted.

 */

static const char *short_options = "0AaBC:cdE:F:f:H:hI:iJjLlmnO:opR:rtuVvW:yZz";

/*

 * Long options for cpio.  Please keep this sorted.

 */

static const struct option {

	const char *name;

	int required;	/* 1 if this option requires an argument */

	int equivalent;	/* Equivalent short option. */

} cpio_longopts[] = {

	{ "b64encode",			0, OPTION_B64ENCODE },

	{ "create",			0, 'o' },

	{ "dereference",		0, 'L' },

	{ "dot",			0, 'V' },

	{ "extract",			0, 'i' },

	{ "file",			1, 'F' },

	{ "format",             	1, 'H' },

	{ "grzip",			0, OPTION_GRZIP },

	{ "help",			0, 'h' },

	{ "insecure",			0, OPTION_INSECURE },

	{ "link",			0, 'l' },

	{ "list",			0, 't' },

	{ "lrzip",			0, OPTION_LRZIP },

	{ "lz4",			0, OPTION_LZ4 },

	{ "lzma",			0, OPTION_LZMA },

	{ "lzop",			0, OPTION_LZOP },

	{ "make-directories",		0, 'd' },

	{ "no-preserve-owner",		0, OPTION_NO_PRESERVE_OWNER },

	{ "null",			0, '0' },

	{ "numeric-uid-gid",		0, 'n' },

	{ "owner",			1, 'R' },

	{ "passphrase",			1, OPTION_PASSPHRASE },

	{ "pass-through",		0, 'p' },

	{ "preserve-modification-time", 0, 'm' },

	{ "preserve-owner",		0, OPTION_PRESERVE_OWNER },

	{ "quiet",			0, OPTION_QUIET },

	{ "unconditional",		0, 'u' },

	{ "uuencode",			0, OPTION_UUENCODE },

	{ "verbose",			0, 'v' },

	{ "version",			0, OPTION_VERSION },

	{ "xz",				0, 'J' },

	{ "zstd",			0, OPTION_ZSTD },

	{ NULL, 0, 0 }

};

/*

 * I used to try to select platform-provided getopt() or

 * getopt_long(), but that caused a lot of headaches.  In particular,

 * I couldn't consistently use long options in the test harness

 * because not all platforms have getopt_long().  That in turn led to

 * overuse of the -W hack in the test harness, which made it rough to

 * run the test harness against GNU cpio.  (I periodically run the

 * test harness here against GNU cpio as a sanity-check.  Yes,

 * I've found a couple of bugs in GNU cpio that way.)

 */

int

cpio_getopt(struct cpio *cpio)

{

	enum { state_start = 0, state_next_word, state_short, state_long };

	static int state = state_start;

	static char *opt_word;

	const struct option *popt, *match = NULL, *match2 = NULL;

	const char *p, *long_prefix = "--";

	size_t optlength;

	int opt = '?';

	int required = 0;

	cpio->argument = NULL;

	/* First time through, initialize everything. */

	if (state == state_start) {

		/* Skip program name. */

		++cpio->argv;

		--cpio->argc;

		state = state_next_word;

	}

	/*

	 * We're ready to look at the next word in argv.

	 */

	if (state == state_next_word) {

		/* No more arguments, so no more options. */

		if (cpio->argv[0] == NULL)

			return (-1);

		/* Doesn't start with '-', so no more options. */

		if (cpio->argv[0][0] != '-')

			return (-1);

		/* "--" marks end of options; consume it and return. */

		if (strcmp(cpio->argv[0], "--") == 0) {

			++cpio->argv;

			--cpio->argc;

			return (-1);

		}

		/* Get next word for parsing. */

		opt_word = *cpio->argv++;

		--cpio->argc;

		if (opt_word[1] == '-') {

			/* Set up long option parser. */

			state = state_long;

			opt_word += 2; /* Skip leading '--' */

		} else {

			/* Set up short option parser. */

			state = state_short;

			++opt_word;  /* Skip leading '-' */

		}

	}

	/*

	 * We're parsing a group of POSIX-style single-character options.

	 */

	if (state == state_short) {

		/* Peel next option off of a group of short options. */

		opt = *opt_word++;

		if (opt == '\0') {

			/* End of this group; recurse to get next option. */

			state = state_next_word;

			return cpio_getopt(cpio);

		}

		/* Does this option take an argument? */

		p = strchr(short_options, opt);

		if (p == NULL)

			return ('?');

		if (p[1] == ':')

			required = 1;

		/* If it takes an argument, parse that. */

		if (required) {

			/* If arg is run-in, opt_word already points to it. */

			if (opt_word[0] == '\0') {

				/* Otherwise, pick up the next word. */

				opt_word = *cpio->argv;

				if (opt_word == NULL) {

					lafe_warnc(0,

					    "Option -%c requires an argument",

					    opt);

					return ('?');

				}

				++cpio->argv;

				--cpio->argc;

			}

			if (opt == 'W') {

				state = state_long;

				long_prefix = "-W "; /* For clearer errors. */

			} else {

				state = state_next_word;

				cpio->argument = opt_word;

			}

		}

	}

	/* We're reading a long option, including -W long=arg convention. */

	if (state == state_long) {

		/* After this long option, we'll be starting a new word. */

		state = state_next_word;

		/* Option name ends at '=' if there is one. */

		p = strchr(opt_word, '=');

		if (p != NULL) {

			optlength = (size_t)(p - opt_word);

			cpio->argument = (char *)(uintptr_t)(p + 1);

		} else {

			optlength = strlen(opt_word);

		}

		/* Search the table for an unambiguous match. */

		for (popt = cpio_longopts; popt->name != NULL; popt++) {

			/* Short-circuit if first chars don't match. */

			if (popt->name[0] != opt_word[0])

				continue;

			/* If option is a prefix of name in table, record it.*/

			if (strncmp(opt_word, popt->name, optlength) == 0) {

				match2 = match; /* Record up to two matches. */

				match = popt;

				/* If it's an exact match, we're done. */

				if (strlen(popt->name) == optlength) {

					match2 = NULL; /* Forget the others. */

					break;

				}

			}

		}

		/* Fail if there wasn't a unique match. */

		if (match == NULL) {

			lafe_warnc(0,

			    "Option %s%s is not supported",

			    long_prefix, opt_word);

			return ('?');

		}

		if (match2 != NULL) {

			lafe_warnc(0,

			    "Ambiguous option %s%s (matches --%s and --%s)",

			    long_prefix, opt_word, match->name, match2->name);

			return ('?');

		}

		/* We've found a unique match; does it need an argument? */

		if (match->required) {

			/* Argument required: get next word if necessary. */

			if (cpio->argument == NULL) {

				cpio->argument = *cpio->argv;

				if (cpio->argument == NULL) {

					lafe_warnc(0,

					    "Option %s%s requires an argument",

					    long_prefix, match->name);

					return ('?');

				}

				++cpio->argv;

				--cpio->argc;

			}

		} else {

			/* Argument forbidden: fail if there is one. */

			if (cpio->argument != NULL) {

				lafe_warnc(0,

				    "Option %s%s does not allow an argument",

				    long_prefix, match->name);

				return ('?');

			}

		}

		return (match->equivalent);

	}

	return (opt);

}

/*

 * Parse the argument to the -R or --owner flag.

 *

 * The format is one of the following:

 *   <username|uid>    - Override user but not group

 *   <username>:   - Override both, group is user's default group

 *   <uid>:    - Override user but not group

 *   <username|uid>:<groupname|gid> - Override both

 *   :<groupname|gid>  - Override group but not user

 *

 * Where uid/gid are decimal representations and groupname/username

 * are names to be looked up in system database.  Note that we try

 * to look up an argument as a name first, then try numeric parsing.

 *

 * A period can be used instead of the colon.

 *

 * Sets uid/gid return as appropriate, -1 indicates uid/gid not specified.

 * TODO: If the spec uses uname/gname, then return those to the caller

 * as well.  If the spec provides uid/gid, just return names as NULL.

 *

 * Returns NULL if no error, otherwise returns error string for display.

 *

 */

const char *

owner_parse(const char *spec, int *uid, int *gid)

{

	static char errbuff[128];

	const char *u, *ue, *g;

	*uid = -1;

	*gid = -1;

	if (spec[0] == '\0')

		return ("Invalid empty user/group spec");

	/*

	 * Split spec into [user][:.][group]

	 *  u -> first char of username, NULL if no username

	 *  ue -> first char after username (colon, period, or \0)

	 *  g -> first char of group name

	 */

	if (*spec == ':' || *spec == '.') {

		/* If spec starts with ':' or '.', then just group. */

		ue = u = NULL;

		g = spec + 1;

	} else {

		/* Otherwise, [user] or [user][:] or [user][:][group] */

		ue = u = spec;

		while (*ue != ':' && *ue != '.' && *ue != '\0')

			++ue;

		g = ue;

		if (*g != '\0') /* Skip : or . to find first char of group. */

			++g;

	}

	if (u != NULL) {

		/* Look up user: ue is first char after end of user. */

		char *user;

		struct passwd *pwent;

		user = (char *)malloc(ue - u + 1);

		if (user == NULL)

			return ("Couldn't allocate memory");

		memcpy(user, u, ue - u);

		user[ue - u] = '\0';

		if ((pwent = getpwnam(user)) != NULL) {

			*uid = pwent->pw_uid;

			if (*ue != '\0')

				*gid = pwent->pw_gid;

		} else {

			char *end;

			errno = 0;

			*uid = (int)strtoul(user, &end, 10);

			if (errno || *end != '\0') {

				snprintf(errbuff, sizeof(errbuff),

				    "Couldn't lookup user ``%s''", user);

				errbuff[sizeof(errbuff) - 1] = '\0';

				free(user);

				return (errbuff);

			}

		}

		free(user);

	}

	if (*g != '\0') {

		struct group *grp;

		if ((grp = getgrnam(g)) != NULL) {

			*gid = grp->gr_gid;

		} else {

			char *end;

			errno = 0;

			*gid = (int)strtoul(g, &end, 10);

			if (errno || *end != '\0') {

				snprintf(errbuff, sizeof(errbuff),

				    "Couldn't lookup group ``%s''", g);

				errbuff[sizeof(errbuff) - 1] = '\0';

				return (errbuff);

			}

		}

	}

	return (NULL);

}