adfafd88b2
This reverts commit 8a07b4033e.
The tests are kept. test-networkd-conf is adjusted to pass.
This fixes #13276. I think current rules are extremely confusing, as the
case in test-networkd-conf shows. We apply some kinds of unescaping (relating
to quoting), but not others (related to escaping of special characters).
But fixing this is hard, because people have adjusted quoting to match
our rules, and if we make the rules "better", things might break in unexpected
places.
286 lines
11 KiB
C
286 lines
11 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
|
|
|
|
#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 (IN_SET(c, '\'', '"') && (flags & EXTRACT_UNQUOTE)) {
|
|
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 = TAKE_PTR(s);
|
|
|
|
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);
|
|
}
|
|
|
|
/* We pass ExtractFlags as unsigned int (to avoid undefined behaviour when passing
|
|
* an object that undergoes default argument promotion as an argument to va_start).
|
|
* Let's make sure that ExtractFlags fits into an unsigned int. */
|
|
assert_cc(sizeof(enum ExtractFlags) <= sizeof(unsigned));
|
|
|
|
int extract_many_words(const char **p, const char *separators, unsigned 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;
|
|
}
|