Merge pull request #16033 from poettering/parse-int-fixlets

various fixes and tweaks for integer parsing
This commit is contained in:
Daan De Meyer 2020-06-06 10:45:35 +02:00 committed by GitHub
commit 6495ceddf3
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5 changed files with 316 additions and 47 deletions

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@ -70,26 +70,24 @@ int parse_pid(const char *s, pid_t* ret_pid) {
}
int parse_mode(const char *s, mode_t *ret) {
char *x;
long l;
unsigned m;
int r;
assert(s);
assert(ret);
s += strspn(s, WHITESPACE);
if (s[0] == '-')
r = safe_atou_full(s, 8 |
SAFE_ATO_REFUSE_PLUS_MINUS, /* Leading '+' or even '-' char? that's just weird,
* refuse. User might have wanted to add mode flags or
* so, but this parser doesn't allow that, so let's
* better be safe. */
&m);
if (r < 0)
return r;
if (m > 07777)
return -ERANGE;
errno = 0;
l = strtol(s, &x, 8);
if (errno > 0)
return -errno;
if (!x || x == s || *x != 0)
return -EINVAL;
if (l < 0 || l > 07777)
return -ERANGE;
*ret = (mode_t) l;
if (ret)
*ret = m;
return 0;
}
@ -354,30 +352,73 @@ int parse_syscall_and_errno(const char *in, char **name, int *error) {
return 0;
}
static const char *mangle_base(const char *s, unsigned *base) {
const char *k;
assert(s);
assert(base);
/* Base already explicitly specified, then don't do anything. */
if (SAFE_ATO_MASK_FLAGS(*base) != 0)
return s;
/* Support Python 3 style "0b" and 0x" prefixes, because they truly make sense, much more than C's "0" prefix for octal. */
k = STARTSWITH_SET(s, "0b", "0B");
if (k) {
*base = 2 | (*base & SAFE_ATO_ALL_FLAGS);
return k;
}
k = STARTSWITH_SET(s, "0o", "0O");
if (k) {
*base = 8 | (*base & SAFE_ATO_ALL_FLAGS);
return k;
}
return s;
}
int safe_atou_full(const char *s, unsigned base, unsigned *ret_u) {
char *x = NULL;
unsigned long l;
assert(s);
assert(base <= 16);
assert(SAFE_ATO_MASK_FLAGS(base) <= 16);
/* strtoul() is happy to parse negative values, and silently
* converts them to unsigned values without generating an
* error. We want a clean error, hence let's look for the "-"
* prefix on our own, and generate an error. But let's do so
* only after strtoul() validated that the string is clean
* otherwise, so that we return EINVAL preferably over
* ERANGE. */
/* strtoul() is happy to parse negative values, and silently converts them to unsigned values without
* generating an error. We want a clean error, hence let's look for the "-" prefix on our own, and
* generate an error. But let's do so only after strtoul() validated that the string is clean
* otherwise, so that we return EINVAL preferably over ERANGE. */
if (FLAGS_SET(base, SAFE_ATO_REFUSE_LEADING_WHITESPACE) &&
strchr(WHITESPACE, s[0]))
return -EINVAL;
s += strspn(s, WHITESPACE);
if (FLAGS_SET(base, SAFE_ATO_REFUSE_PLUS_MINUS) &&
IN_SET(s[0], '+', '-'))
return -EINVAL; /* Note that we check the "-" prefix again a second time below, but return a
* different error. I.e. if the SAFE_ATO_REFUSE_PLUS_MINUS flag is set we
* blanket refuse +/- prefixed integers, while if it is missing we'll just
* return ERANGE, because the string actually parses correctly, but doesn't
* fit in the return type. */
if (FLAGS_SET(base, SAFE_ATO_REFUSE_LEADING_ZERO) &&
s[0] == '0' && !streq(s, "0"))
return -EINVAL; /* This is particularly useful to avoid ambiguities between C's octal
* notation and assumed-to-be-decimal integers with a leading zero. */
s = mangle_base(s, &base);
errno = 0;
l = strtoul(s, &x, base);
l = strtoul(s, &x, SAFE_ATO_MASK_FLAGS(base) /* Let's mask off the flags bits so that only the actual
* base is left */);
if (errno > 0)
return -errno;
if (!x || x == s || *x != 0)
return -EINVAL;
if (s[0] == '-')
if (l != 0 && s[0] == '-')
return -ERANGE;
if ((unsigned long) (unsigned) l != l)
return -ERANGE;
@ -389,13 +430,17 @@ int safe_atou_full(const char *s, unsigned base, unsigned *ret_u) {
}
int safe_atoi(const char *s, int *ret_i) {
unsigned base = 0;
char *x = NULL;
long l;
assert(s);
s += strspn(s, WHITESPACE);
s = mangle_base(s, &base);
errno = 0;
l = strtol(s, &x, 0);
l = strtol(s, &x, base);
if (errno > 0)
return -errno;
if (!x || x == s || *x != 0)
@ -414,16 +459,31 @@ int safe_atollu_full(const char *s, unsigned base, long long unsigned *ret_llu)
unsigned long long l;
assert(s);
assert(SAFE_ATO_MASK_FLAGS(base) <= 16);
if (FLAGS_SET(base, SAFE_ATO_REFUSE_LEADING_WHITESPACE) &&
strchr(WHITESPACE, s[0]))
return -EINVAL;
s += strspn(s, WHITESPACE);
if (FLAGS_SET(base, SAFE_ATO_REFUSE_PLUS_MINUS) &&
IN_SET(s[0], '+', '-'))
return -EINVAL;
if (FLAGS_SET(base, SAFE_ATO_REFUSE_LEADING_ZERO) &&
s[0] == '0' && s[1] != 0)
return -EINVAL;
s = mangle_base(s, &base);
errno = 0;
l = strtoull(s, &x, base);
l = strtoull(s, &x, SAFE_ATO_MASK_FLAGS(base));
if (errno > 0)
return -errno;
if (!x || x == s || *x != 0)
return -EINVAL;
if (*s == '-')
if (l != 0 && s[0] == '-')
return -ERANGE;
if (ret_llu)
@ -433,13 +493,17 @@ int safe_atollu_full(const char *s, unsigned base, long long unsigned *ret_llu)
}
int safe_atolli(const char *s, long long int *ret_lli) {
unsigned base = 0;
char *x = NULL;
long long l;
assert(s);
s += strspn(s, WHITESPACE);
s = mangle_base(s, &base);
errno = 0;
l = strtoll(s, &x, 0);
l = strtoll(s, &x, base);
if (errno > 0)
return -errno;
if (!x || x == s || *x != 0)
@ -452,20 +516,22 @@ int safe_atolli(const char *s, long long int *ret_lli) {
}
int safe_atou8(const char *s, uint8_t *ret) {
char *x = NULL;
unsigned base = 0;
unsigned long l;
char *x = NULL;
assert(s);
s += strspn(s, WHITESPACE);
s = mangle_base(s, &base);
errno = 0;
l = strtoul(s, &x, 0);
l = strtoul(s, &x, base);
if (errno > 0)
return -errno;
if (!x || x == s || *x != 0)
return -EINVAL;
if (s[0] == '-')
if (l != 0 && s[0] == '-')
return -ERANGE;
if ((unsigned long) (uint8_t) l != l)
return -ERANGE;
@ -480,34 +546,53 @@ int safe_atou16_full(const char *s, unsigned base, uint16_t *ret) {
unsigned long l;
assert(s);
assert(ret);
assert(base <= 16);
assert(SAFE_ATO_MASK_FLAGS(base) <= 16);
if (FLAGS_SET(base, SAFE_ATO_REFUSE_LEADING_WHITESPACE) &&
strchr(WHITESPACE, s[0]))
return -EINVAL;
s += strspn(s, WHITESPACE);
if (FLAGS_SET(base, SAFE_ATO_REFUSE_PLUS_MINUS) &&
IN_SET(s[0], '+', '-'))
return -EINVAL;
if (FLAGS_SET(base, SAFE_ATO_REFUSE_LEADING_ZERO) &&
s[0] == '0' && s[1] != 0)
return -EINVAL;
s = mangle_base(s, &base);
errno = 0;
l = strtoul(s, &x, base);
l = strtoul(s, &x, SAFE_ATO_MASK_FLAGS(base));
if (errno > 0)
return -errno;
if (!x || x == s || *x != 0)
return -EINVAL;
if (s[0] == '-')
if (l != 0 && s[0] == '-')
return -ERANGE;
if ((unsigned long) (uint16_t) l != l)
return -ERANGE;
*ret = (uint16_t) l;
if (ret)
*ret = (uint16_t) l;
return 0;
}
int safe_atoi16(const char *s, int16_t *ret) {
unsigned base = 0;
char *x = NULL;
long l;
assert(s);
s += strspn(s, WHITESPACE);
s = mangle_base(s, &base);
errno = 0;
l = strtol(s, &x, 0);
l = strtol(s, &x, base);
if (errno > 0)
return -errno;
if (!x || x == s || *x != 0)

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@ -21,6 +21,12 @@ int parse_range(const char *t, unsigned *lower, unsigned *upper);
int parse_errno(const char *t);
int parse_syscall_and_errno(const char *in, char **name, int *error);
#define SAFE_ATO_REFUSE_PLUS_MINUS (1U << 30)
#define SAFE_ATO_REFUSE_LEADING_ZERO (1U << 29)
#define SAFE_ATO_REFUSE_LEADING_WHITESPACE (1U << 28)
#define SAFE_ATO_ALL_FLAGS (SAFE_ATO_REFUSE_PLUS_MINUS|SAFE_ATO_REFUSE_LEADING_ZERO|SAFE_ATO_REFUSE_LEADING_WHITESPACE)
#define SAFE_ATO_MASK_FLAGS(base) ((base) & ~SAFE_ATO_ALL_FLAGS)
int safe_atou_full(const char *s, unsigned base, unsigned *ret_u);
static inline int safe_atou(const char *s, unsigned *ret_u) {

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@ -49,7 +49,15 @@ int parse_uid(const char *s, uid_t *ret) {
assert(s);
assert_cc(sizeof(uid_t) == sizeof(uint32_t));
r = safe_atou32_full(s, 10, &uid);
/* We are very strict when parsing UIDs, and prohibit +/- as prefix, leading zero as prefix, and
* whitespace. We do this, since this call is often used in a context where we parse things as UID
* first, and if that doesn't work we fall back to NSS. Thus we really want to make sure that UIDs
* are parsed as UIDs only if they really really look like UIDs. */
r = safe_atou32_full(s, 10
| SAFE_ATO_REFUSE_PLUS_MINUS
| SAFE_ATO_REFUSE_LEADING_ZERO
| SAFE_ATO_REFUSE_LEADING_WHITESPACE, &uid);
if (r < 0)
return r;
@ -66,22 +74,39 @@ int parse_uid(const char *s, uid_t *ret) {
}
int parse_uid_range(const char *s, uid_t *ret_lower, uid_t *ret_upper) {
uint32_t u, l;
_cleanup_free_ char *word = NULL;
uid_t l, u;
int r;
assert(s);
assert(ret_lower);
assert(ret_upper);
r = parse_range(s, &l, &u);
r = extract_first_word(&s, &word, "-", EXTRACT_DONT_COALESCE_SEPARATORS);
if (r < 0)
return r;
if (r == 0)
return -EINVAL;
r = parse_uid(word, &l);
if (r < 0)
return r;
if (l > u)
/* Check for the upper bound and extract it if needed */
if (!s)
/* Single number with no dash. */
u = l;
else if (!*s)
/* Trailing dash is an error. */
return -EINVAL;
else {
r = parse_uid(s, &u);
if (r < 0)
return r;
if (!uid_is_valid(l) || !uid_is_valid(u))
return -ENXIO;
if (l > u)
return -EINVAL;
}
*ret_lower = l;
*ret_upper = u;

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@ -75,14 +75,22 @@ static void test_parse_mode(void) {
mode_t m;
assert_se(parse_mode("-1", &m) < 0);
assert_se(parse_mode("+1", &m) < 0);
assert_se(parse_mode("", &m) < 0);
assert_se(parse_mode("888", &m) < 0);
assert_se(parse_mode("77777", &m) < 0);
assert_se(parse_mode("544", &m) >= 0 && m == 0544);
assert_se(parse_mode("0544", &m) >= 0 && m == 0544);
assert_se(parse_mode("00544", &m) >= 0 && m == 0544);
assert_se(parse_mode("777", &m) >= 0 && m == 0777);
assert_se(parse_mode("0777", &m) >= 0 && m == 0777);
assert_se(parse_mode("00777", &m) >= 0 && m == 0777);
assert_se(parse_mode("7777", &m) >= 0 && m == 07777);
assert_se(parse_mode("07777", &m) >= 0 && m == 07777);
assert_se(parse_mode("007777", &m) >= 0 && m == 07777);
assert_se(parse_mode("0", &m) >= 0 && m == 0);
assert_se(parse_mode(" 1", &m) >= 0 && m == 1);
}
static void test_parse_size(void) {
@ -358,6 +366,18 @@ static void test_safe_atolli(void) {
assert_se(r == 0);
assert_se(l == -12345);
r = safe_atolli("0x5", &l);
assert_se(r == 0);
assert_se(l == 5);
r = safe_atolli("0o6", &l);
assert_se(r == 0);
assert_se(l == 6);
r = safe_atolli("0B101", &l);
assert_se(r == 0);
assert_se(l == 5);
r = safe_atolli("12345678901234567890", &l);
assert_se(r == -ERANGE);
@ -431,6 +451,14 @@ static void test_safe_atoi16(void) {
assert_se(r == 0);
assert_se(l == 32767);
r = safe_atoi16("0o11", &l);
assert_se(r == 0);
assert_se(l == 9);
r = safe_atoi16("0B110", &l);
assert_se(r == 0);
assert_se(l == 6);
r = safe_atoi16("36536", &l);
assert_se(r == -ERANGE);
@ -475,6 +503,13 @@ static void test_safe_atoux16(void) {
r = safe_atoux16(" -1", &l);
assert_se(r == -ERANGE);
r = safe_atoux16("0b1", &l);
assert_se(r == 0);
assert_se(l == 177);
r = safe_atoux16("0o70", &l);
assert_se(r == -EINVAL);
r = safe_atoux16("junk", &l);
assert_se(r == -EINVAL);
@ -500,6 +535,14 @@ static void test_safe_atou64(void) {
assert_se(r == 0);
assert_se(l == 12345);
r = safe_atou64("0o11", &l);
assert_se(r == 0);
assert_se(l == 9);
r = safe_atou64("0b11", &l);
assert_se(r == 0);
assert_se(l == 3);
r = safe_atou64("18446744073709551617", &l);
assert_se(r == -ERANGE);
@ -542,6 +585,14 @@ static void test_safe_atoi64(void) {
assert_se(r == 0);
assert_se(l == 32767);
r = safe_atoi64(" 0o20", &l);
assert_se(r == 0);
assert_se(l == 16);
r = safe_atoi64(" 0b01010", &l);
assert_se(r == 0);
assert_se(l == 10);
r = safe_atoi64("9223372036854775813", &l);
assert_se(r == -ERANGE);
@ -577,6 +628,13 @@ static void test_safe_atoux64(void) {
assert_se(r == 0);
assert_se(l == 0x12345);
r = safe_atoux64("0b11011", &l);
assert_se(r == 0);
assert_se(l == 11603985);
r = safe_atoux64("0o11011", &l);
assert_se(r == -EINVAL);
r = safe_atoux64("18446744073709551617", &l);
assert_se(r == -ERANGE);

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@ -42,6 +42,22 @@ static void test_parse_uid(void) {
log_info("/* %s */", __func__);
r = parse_uid("0", &uid);
assert_se(r == 0);
assert_se(uid == 0);
r = parse_uid("1", &uid);
assert_se(r == 0);
assert_se(uid == 1);
r = parse_uid("01", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 1);
r = parse_uid("001", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 1);
r = parse_uid("100", &uid);
assert_se(r == 0);
assert_se(uid == 100);
@ -54,13 +70,57 @@ static void test_parse_uid(void) {
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid("0o1234", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid("0b1234", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid("+1234", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid("-1234", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid(" 1234", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid("01234", &uid);
assert_se(r == 0);
assert_se(uid == 1234);
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid("001234", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid("0001234", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid("-0", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid("+0", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid("00", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid("000", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 100);
r = parse_uid("asdsdas", &uid);
assert_se(r == -EINVAL);
assert_se(uid == 1234);
assert_se(uid == 100);
}
static void test_uid_ptr(void) {
@ -359,6 +419,39 @@ static void test_gid_lists_ops(void) {
assert_se(gids);
}
static void test_parse_uid_range(void) {
uid_t a = 4711, b = 4711;
log_info("/* %s */", __func__);
assert_se(parse_uid_range("", &a, &b) == -EINVAL && a == 4711 && b == 4711);
assert_se(parse_uid_range(" ", &a, &b) == -EINVAL && a == 4711 && b == 4711);
assert_se(parse_uid_range("x", &a, &b) == -EINVAL && a == 4711 && b == 4711);
assert_se(parse_uid_range("0", &a, &b) >= 0 && a == 0 && b == 0);
assert_se(parse_uid_range("1", &a, &b) >= 0 && a == 1 && b == 1);
assert_se(parse_uid_range("2-2", &a, &b) >= 0 && a == 2 && b == 2);
assert_se(parse_uid_range("3-3", &a, &b) >= 0 && a == 3 && b == 3);
assert_se(parse_uid_range("4-5", &a, &b) >= 0 && a == 4 && b == 5);
assert_se(parse_uid_range("7-6", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range("-1", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range("01", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range("001", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range("+1", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range("1--1", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range(" 1", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range(" 1-2", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range("1 -2", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range("1- 2", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range("1-2 ", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range("01-2", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range("1-02", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range("001-2", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range("1-002", &a, &b) == -EINVAL && a == 4 && b == 5);
assert_se(parse_uid_range(" 01", &a, &b) == -EINVAL && a == 4 && b == 5);
}
int main(int argc, char *argv[]) {
test_uid_to_name_one(0, "root");
test_uid_to_name_one(UID_NOBODY, NOBODY_USER_NAME);
@ -396,5 +489,7 @@ int main(int argc, char *argv[]) {
test_in_gid();
test_gid_lists_ops();
test_parse_uid_range();
return 0;
}