[thirdparty/systemd.git] / src / basic / extract-word.c

/***
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <errno.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>

#include "alloc-util.h"
#include "escape.h"
#include "extract-word.h"
#include "log.h"
#include "macro.h"
#include "string-util.h"
#include "utf8.h"

int extract_first_word(const char **p, char **ret, const char *separators, ExtractFlags flags) {
        _cleanup_free_ char *s = NULL;
        size_t allocated = 0, sz = 0;
        char c;
        int r;

        char quote = 0;                 /* 0 or ' or " */
        bool backslash = false;         /* whether we've just seen a backslash */

        assert(p);
        assert(ret);

        /* Bail early if called after last value or with no input */
        if (!*p)
                goto finish;
        c = **p;

        if (!separators)
                separators = WHITESPACE;

        /* Parses the first word of a string, and returns it in
         * *ret. Removes all quotes in the process. When parsing fails
         * (because of an uneven number of quotes or similar), leaves
         * the pointer *p at the first invalid character. */

        if (flags & EXTRACT_DONT_COALESCE_SEPARATORS)
                if (!GREEDY_REALLOC(s, allocated, sz+1))
                        return -ENOMEM;

        for (;; (*p)++, c = **p) {
                if (c == 0)
                        goto finish_force_terminate;
                else if (strchr(separators, c)) {
                        if (flags & EXTRACT_DONT_COALESCE_SEPARATORS) {
                                (*p)++;
                                goto finish_force_next;
                        }
                } else {
                        /* We found a non-blank character, so we will always
                         * want to return a string (even if it is empty),
                         * allocate it here. */
                        if (!GREEDY_REALLOC(s, allocated, sz+1))
                                return -ENOMEM;
                        break;
                }
        }

        for (;; (*p)++, c = **p) {
                if (backslash) {
                        if (!GREEDY_REALLOC(s, allocated, sz+7))
                                return -ENOMEM;

                        if (c == 0) {
                                if ((flags & EXTRACT_CUNESCAPE_RELAX) &&
                                    (!quote || flags & EXTRACT_RELAX)) {
                                        /* If we find an unquoted trailing backslash and we're in
                                         * EXTRACT_CUNESCAPE_RELAX mode, keep it verbatim in the
                                         * output.
                                         *
                                         * Unbalanced quotes will only be allowed in EXTRACT_RELAX
                                         * mode, EXTRACT_CUNESCAPE_RELAX mode does not allow them.
                                         */
                                        s[sz++] = '\\';
                                        goto finish_force_terminate;
                                }
                                if (flags & EXTRACT_RELAX)
                                        goto finish_force_terminate;
                                return -EINVAL;
                        }

                        if (flags & EXTRACT_CUNESCAPE) {
                                bool eight_bit = false;
                                char32_t u;

                                r = cunescape_one(*p, (size_t) -1, &u, &eight_bit);
                                if (r < 0) {
                                        if (flags & EXTRACT_CUNESCAPE_RELAX) {
                                                s[sz++] = '\\';
                                                s[sz++] = c;
                                        } else
                                                return -EINVAL;
                                } else {
                                        (*p) += r - 1;

                                        if (eight_bit)
                                                s[sz++] = u;
                                        else
                                                sz += utf8_encode_unichar(s + sz, u);
                                }
                        } else
                                s[sz++] = c;

                        backslash = false;

                } else if (quote) {     /* inside either single or double quotes */
                        for (;; (*p)++, c = **p) {
                                if (c == 0) {
                                        if (flags & EXTRACT_RELAX)
                                                goto finish_force_terminate;
                                        return -EINVAL;
                                } else if (c == quote) {        /* found the end quote */
                                        quote = 0;
                                        break;
                                } else if (c == '\\' && !(flags & EXTRACT_RETAIN_ESCAPE)) {
                                        backslash = true;
                                        break;
                                } else {
                                        if (!GREEDY_REALLOC(s, allocated, sz+2))
                                                return -ENOMEM;

                                        s[sz++] = c;
                                }
                        }

                } else {
                        for (;; (*p)++, c = **p) {
                                if (c == 0)
                                        goto finish_force_terminate;
                                else if ((c == '\'' || c == '"') && (flags & EXTRACT_QUOTES)) {
                                        quote = c;
                                        break;
                                } else if (c == '\\' && !(flags & EXTRACT_RETAIN_ESCAPE)) {
                                        backslash = true;
                                        break;
                                } else if (strchr(separators, c)) {
                                        if (flags & EXTRACT_DONT_COALESCE_SEPARATORS) {
                                                (*p)++;
                                                goto finish_force_next;
                                        }
                                        /* Skip additional coalesced separators. */
                                        for (;; (*p)++, c = **p) {
                                                if (c == 0)
                                                        goto finish_force_terminate;
                                                if (!strchr(separators, c))
                                                        break;
                                        }
                                        goto finish;

                                } else {
                                        if (!GREEDY_REALLOC(s, allocated, sz+2))
                                                return -ENOMEM;

                                        s[sz++] = c;
                                }
                        }
                }
        }

finish_force_terminate:
        *p = NULL;
finish:
        if (!s) {
                *p = NULL;
                *ret = NULL;
                return 0;
        }

finish_force_next:
        s[sz] = 0;
        *ret = s;
        s = NULL;

        return 1;
}

int extract_first_word_and_warn(
                const char **p,
                char **ret,
                const char *separators,
                ExtractFlags flags,
                const char *unit,
                const char *filename,
                unsigned line,
                const char *rvalue) {

        /* Try to unquote it, if it fails, warn about it and try again
         * but this time using EXTRACT_CUNESCAPE_RELAX to keep the
         * backslashes verbatim in invalid escape sequences. */

        const char *save;
        int r;

        save = *p;
        r = extract_first_word(p, ret, separators, flags);
        if (r >= 0)
                return r;

        if (r == -EINVAL && !(flags & EXTRACT_CUNESCAPE_RELAX)) {

                /* Retry it with EXTRACT_CUNESCAPE_RELAX. */
                *p = save;
                r = extract_first_word(p, ret, separators, flags|EXTRACT_CUNESCAPE_RELAX);
                if (r >= 0) {
                        /* It worked this time, hence it must have been an invalid escape sequence. */
                        log_syntax(unit, LOG_WARNING, filename, line, EINVAL, "Ignoring unknown escape sequences: \"%s\"", *ret);
                        return r;
                }

                /* If it's still EINVAL; then it must be unbalanced quoting, report this. */
                if (r == -EINVAL)
                        return log_syntax(unit, LOG_ERR, filename, line, r, "Unbalanced quoting, ignoring: \"%s\"", rvalue);
        }

        /* Can be any error, report it */
        return log_syntax(unit, LOG_ERR, filename, line, r, "Unable to decode word \"%s\", ignoring: %m", rvalue);
}

int extract_many_words(const char **p, const char *separators, ExtractFlags flags, ...) {
        va_list ap;
        char **l;
        int n = 0, i, c, r;

        /* Parses a number of words from a string, stripping any
         * quotes if necessary. */

        assert(p);

        /* Count how many words are expected */
        va_start(ap, flags);
        for (;;) {
                if (!va_arg(ap, char **))
                        break;
                n++;
        }
        va_end(ap);

        if (n <= 0)
                return 0;

        /* Read all words into a temporary array */
        l = newa0(char*, n);
        for (c = 0; c < n; c++) {

                r = extract_first_word(p, &l[c], separators, flags);
                if (r < 0) {
                        int j;

                        for (j = 0; j < c; j++)
                                free(l[j]);

                        return r;
                }

                if (r == 0)
                        break;
        }

        /* If we managed to parse all words, return them in the passed
         * in parameters */
        va_start(ap, flags);
        for (i = 0; i < n; i++) {
                char **v;

                v = va_arg(ap, char **);
                assert(v);

                *v = l[i];
        }
        va_end(ap);

        return c;
}
Commit	Line	Data
84ac7bea LP	1	/***
	2	This file is part of systemd.
	3
	4	Copyright 2010 Lennart Poettering
	5
	6	systemd is free software; you can redistribute it and/or modify it
	7	under the terms of the GNU Lesser General Public License as published by
	8	the Free Software Foundation; either version 2.1 of the License, or
	9	(at your option) any later version.
	10
	11	systemd is distributed in the hope that it will be useful, but
	12	WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	Lesser General Public License for more details.
	15
	16	You should have received a copy of the GNU Lesser General Public License
	17	along with systemd; If not, see <http://www.gnu.org/licenses/>.
	18	***/
	19
11c3a366 TA	20	#include <errno.h>
	21	#include <stdarg.h>
	22	#include <stdbool.h>
	23	#include <stddef.h>
	24	#include <stdint.h>
	25	#include <stdlib.h>
	26	#include <string.h>
	27	#include <syslog.h>
	28
b5efdb8a	29	#include "alloc-util.h"
4f5dd394	30	#include "escape.h"
b11d6a7b	31	#include "extract-word.h"
11c3a366 TA	32	#include "log.h"
11c3a366 TA	33	#include "macro.h"
b11d6a7b	34	#include "string-util.h"
84ac7bea	35	#include "utf8.h"
84ac7bea LP	36
	37	int extract_first_word(const char p, char ret, const char *separators, ExtractFlags flags) {
	38	_cleanup_free_ char *s = NULL;
	39	size_t allocated = 0, sz = 0;
b85e1c25	40	char c;
84ac7bea LP	41	int r;
	42
	43	char quote = 0; /* 0 or ' or " */
	44	bool backslash = false; /* whether we've just seen a backslash */
84ac7bea LP	45
	46	assert(p);
	47	assert(ret);
	48
84ac7bea LP	49	/* Bail early if called after last value or with no input */
84ac7bea LP	50	if (!*p)
c58bd76a	51	goto finish;
93de9eb7	52	c = **p;
84ac7bea	53
8372da44 FB	54	if (!separators)
	55	separators = WHITESPACE;
	56
84ac7bea LP	57	/* Parses the first word of a string, and returns it in
	58	* *ret. Removes all quotes in the process. When parsing fails
	59	* (because of an uneven number of quotes or similar), leaves
	60	* the pointer p at the first invalid character. /
	61
b85e1c25 FB	62	if (flags & EXTRACT_DONT_COALESCE_SEPARATORS)
	63	if (!GREEDY_REALLOC(s, allocated, sz+1))
	64	return -ENOMEM;
84ac7bea	65
313cefa1	66	for (;; (p)++, c = *p) {
b85e1c25 FB	67	if (c == 0)
	68	goto finish_force_terminate;
	69	else if (strchr(separators, c)) {
93de9eb7	70	if (flags & EXTRACT_DONT_COALESCE_SEPARATORS) {
313cefa1	71	(*p)++;
b85e1c25	72	goto finish_force_next;
93de9eb7	73	}
b85e1c25	74	} else {
84ac7bea LP	75	/* We found a non-blank character, so we will always
	76	* want to return a string (even if it is empty),
	77	* allocate it here. */
	78	if (!GREEDY_REALLOC(s, allocated, sz+1))
	79	return -ENOMEM;
b85e1c25	80	break;
84ac7bea	81	}
b85e1c25 FB	82	}
b85e1c25 FB	83
313cefa1	84	for (;; (p)++, c = *p) {
84ac7bea LP	85	if (backslash) {
	86	if (!GREEDY_REALLOC(s, allocated, sz+7))
	87	return -ENOMEM;
	88
	89	if (c == 0) {
	90	if ((flags & EXTRACT_CUNESCAPE_RELAX) &&
	91	(!quote \|\| flags & EXTRACT_RELAX)) {
	92	/* If we find an unquoted trailing backslash and we're in
	93	* EXTRACT_CUNESCAPE_RELAX mode, keep it verbatim in the
	94	* output.
	95	*
	96	* Unbalanced quotes will only be allowed in EXTRACT_RELAX
	97	* mode, EXTRACT_CUNESCAPE_RELAX mode does not allow them.
	98	*/
	99	s[sz++] = '\\';
	100	goto finish_force_terminate;
	101	}
	102	if (flags & EXTRACT_RELAX)
	103	goto finish_force_terminate;
	104	return -EINVAL;
	105	}
	106
	107	if (flags & EXTRACT_CUNESCAPE) {
3565e095	108	bool eight_bit = false;
c932fb71	109	char32_t u;
84ac7bea	110
3565e095	111	r = cunescape_one(*p, (size_t) -1, &u, &eight_bit);
84ac7bea LP	112	if (r < 0) {
	113	if (flags & EXTRACT_CUNESCAPE_RELAX) {
	114	s[sz++] = '\\';
	115	s[sz++] = c;
3ff13c29 FB	116	} else
	117	return -EINVAL;
	118	} else {
	119	(*p) += r - 1;
	120
3565e095 ZJS	121	if (eight_bit)
3565e095 ZJS	122	s[sz++] = u;
3ff13c29	123	else
3565e095	124	sz += utf8_encode_unichar(s + sz, u);
84ac7bea	125	}
84ac7bea LP	126	} else
	127	s[sz++] = c;
	128
84ac7bea LP	129	backslash = false;
	130
	131	} else if (quote) { /* inside either single or double quotes */
313cefa1	132	for (;; (p)++, c = *p) {
27fc921b FB	133	if (c == 0) {
	134	if (flags & EXTRACT_RELAX)
	135	goto finish_force_terminate;
	136	return -EINVAL;
	137	} else if (c == quote) { /* found the end quote */
	138	quote = 0;
	139	break;
c89f52ac	140	} else if (c == '\\' && !(flags & EXTRACT_RETAIN_ESCAPE)) {
27fc921b FB	141	backslash = true;
	142	break;
	143	} else {
	144	if (!GREEDY_REALLOC(s, allocated, sz+2))
	145	return -ENOMEM;
84ac7bea	146
27fc921b FB	147	s[sz++] = c;
27fc921b FB	148	}
84ac7bea LP	149	}
84ac7bea LP	150
84ac7bea	151	} else {
313cefa1	152	for (;; (p)++, c = *p) {
27fc921b FB	153	if (c == 0)
	154	goto finish_force_terminate;
	155	else if ((c == '\'' \|\| c == '"') && (flags & EXTRACT_QUOTES)) {
	156	quote = c;
	157	break;
c89f52ac	158	} else if (c == '\\' && !(flags & EXTRACT_RETAIN_ESCAPE)) {
27fc921b FB	159	backslash = true;
	160	break;
	161	} else if (strchr(separators, c)) {
	162	if (flags & EXTRACT_DONT_COALESCE_SEPARATORS) {
313cefa1	163	(*p)++;
27fc921b FB	164	goto finish_force_next;
27fc921b FB	165	}
0247447e	166	/* Skip additional coalesced separators. */
313cefa1	167	for (;; (p)++, c = *p) {
0247447e FB	168	if (c == 0)
	169	goto finish_force_terminate;
	170	if (!strchr(separators, c))
	171	break;
	172	}
	173	goto finish;
	174
27fc921b FB	175	} else {
	176	if (!GREEDY_REALLOC(s, allocated, sz+2))
	177	return -ENOMEM;
84ac7bea	178
27fc921b FB	179	s[sz++] = c;
27fc921b FB	180	}
84ac7bea LP	181	}
84ac7bea LP	182	}
84ac7bea LP	183	}
	184
	185	finish_force_terminate:
	186	*p = NULL;
	187	finish:
	188	if (!s) {
	189	*p = NULL;
	190	*ret = NULL;
	191	return 0;
	192	}
	193
	194	finish_force_next:
	195	s[sz] = 0;
	196	*ret = s;
	197	s = NULL;
	198
	199	return 1;
	200	}
	201
	202	int extract_first_word_and_warn(
	203	const char **p,
	204	char **ret,
	205	const char *separators,
	206	ExtractFlags flags,
	207	const char *unit,
	208	const char *filename,
	209	unsigned line,
	210	const char *rvalue) {
	211
dea7b6b0 LP	212	/* Try to unquote it, if it fails, warn about it and try again
	213	* but this time using EXTRACT_CUNESCAPE_RELAX to keep the
	214	* backslashes verbatim in invalid escape sequences. */
	215
84ac7bea LP	216	const char *save;
	217	int r;
	218
	219	save = *p;
	220	r = extract_first_word(p, ret, separators, flags);
dea7b6b0 LP	221	if (r >= 0)
	222	return r;
	223
	224	if (r == -EINVAL && !(flags & EXTRACT_CUNESCAPE_RELAX)) {
84ac7bea LP	225
	226	/* Retry it with EXTRACT_CUNESCAPE_RELAX. */
	227	*p = save;
	228	r = extract_first_word(p, ret, separators, flags\|EXTRACT_CUNESCAPE_RELAX);
dea7b6b0	229	if (r >= 0) {
330785f5 ZJS	230	/* It worked this time, hence it must have been an invalid escape sequence. */
330785f5 ZJS	231	log_syntax(unit, LOG_WARNING, filename, line, EINVAL, "Ignoring unknown escape sequences: \"%s\"", *ret);
dea7b6b0 LP	232	return r;
	233	}
	234
	235	/* If it's still EINVAL; then it must be unbalanced quoting, report this. */
	236	if (r == -EINVAL)
	237	return log_syntax(unit, LOG_ERR, filename, line, r, "Unbalanced quoting, ignoring: \"%s\"", rvalue);
84ac7bea LP	238	}
84ac7bea LP	239
dea7b6b0 LP	240	/* Can be any error, report it */
dea7b6b0 LP	241	return log_syntax(unit, LOG_ERR, filename, line, r, "Unable to decode word \"%s\", ignoring: %m", rvalue);
84ac7bea LP	242	}
	243
	244	int extract_many_words(const char *p, const char separators, ExtractFlags flags, ...) {
	245	va_list ap;
	246	char **l;
	247	int n = 0, i, c, r;
	248
	249	/* Parses a number of words from a string, stripping any
	250	* quotes if necessary. */
	251
	252	assert(p);
	253
	254	/* Count how many words are expected */
	255	va_start(ap, flags);
	256	for (;;) {
	257	if (!va_arg(ap, char **))
	258	break;
	259	n++;
	260	}
	261	va_end(ap);
	262
	263	if (n <= 0)
	264	return 0;
	265
	266	/* Read all words into a temporary array */
	267	l = newa0(char*, n);
	268	for (c = 0; c < n; c++) {
	269
	270	r = extract_first_word(p, &l[c], separators, flags);
	271	if (r < 0) {
	272	int j;
	273
	274	for (j = 0; j < c; j++)
	275	free(l[j]);
	276
	277	return r;
	278	}
	279
	280	if (r == 0)
	281	break;
	282	}
	283
	284	/* If we managed to parse all words, return them in the passed
	285	* in parameters */
	286	va_start(ap, flags);
	287	for (i = 0; i < n; i++) {
	288	char **v;
	289
	290	v = va_arg(ap, char **);
	291	assert(v);
	292
	293	*v = l[i];
	294	}
	295	va_end(ap);
	296
	297	return c;
	298	}