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authorLennart Poettering <lennart@poettering.net>2016-07-18 11:12:47 +0200
committerGitHub <noreply@github.com>2016-07-18 11:12:47 +0200
commitb6070695c8f94bf47ffca8557048bdd16a833a12 (patch)
tree08b806c2ea2ff89f55fdd49837832f11833327cd
parentd909beef0a97d931de92723746a4e3ae9c7f1194 (diff)
parentb60df13b39c0237f9cb1114076464d2431e6bee5 (diff)
Merge pull request #3745 from keszybz/fix-make-nulstr-confusion
Fix make nulstr confusion
-rw-r--r--src/basic/strv.c29
-rw-r--r--src/shared/ask-password-api.c6
-rw-r--r--src/test/test-strv.c6
3 files changed, 32 insertions, 9 deletions
diff --git a/src/basic/strv.c b/src/basic/strv.c
index db315ac10a..34e464d253 100644
--- a/src/basic/strv.c
+++ b/src/basic/strv.c
@@ -638,6 +638,17 @@ char **strv_remove(char **l, const char *s) {
}
char **strv_parse_nulstr(const char *s, size_t l) {
+ /* l is the length of the input data, which will be split at NULs into
+ * elements of the resulting strv. Hence, the number of items in the resulting strv
+ * will be equal to one plus the number of NUL bytes in the l bytes starting at s,
+ * unless s[l-1] is NUL, in which case the final empty string is not stored in
+ * the resulting strv, and length is equal to the number of NUL bytes.
+ *
+ * Note that contrary to a normal nulstr which cannot contain empty strings, because
+ * the input data is terminated by any two consequent NUL bytes, this parser accepts
+ * empty strings in s.
+ */
+
const char *p;
unsigned c = 0, i = 0;
char **v;
@@ -700,6 +711,13 @@ char **strv_split_nulstr(const char *s) {
}
int strv_make_nulstr(char **l, char **p, size_t *q) {
+ /* A valid nulstr with two NULs at the end will be created, but
+ * q will be the length without the two trailing NULs. Thus the output
+ * string is a valid nulstr and can be iterated over using NULSTR_FOREACH,
+ * and can also be parsed by strv_parse_nulstr as long as the length
+ * is provided separately.
+ */
+
size_t n_allocated = 0, n = 0;
_cleanup_free_ char *m = NULL;
char **i;
@@ -712,7 +730,7 @@ int strv_make_nulstr(char **l, char **p, size_t *q) {
z = strlen(*i);
- if (!GREEDY_REALLOC(m, n_allocated, n + z + 1))
+ if (!GREEDY_REALLOC(m, n_allocated, n + z + 2))
return -ENOMEM;
memcpy(m + n, *i, z + 1);
@@ -723,11 +741,14 @@ int strv_make_nulstr(char **l, char **p, size_t *q) {
m = new0(char, 1);
if (!m)
return -ENOMEM;
- n = 0;
- }
+ n = 1;
+ } else
+ /* make sure there is a second extra NUL at the end of resulting nulstr */
+ m[n] = '\0';
+ assert(n > 0);
*p = m;
- *q = n;
+ *q = n - 1;
m = NULL;
diff --git a/src/shared/ask-password-api.c b/src/shared/ask-password-api.c
index a86b0db554..65151b19a6 100644
--- a/src/shared/ask-password-api.c
+++ b/src/shared/ask-password-api.c
@@ -139,11 +139,7 @@ static int add_to_keyring(const char *keyname, AskPasswordFlags flags, char **pa
if (r < 0)
return r;
- /* Truncate trailing NUL */
- assert(n > 0);
- assert(p[n-1] == 0);
-
- serial = add_key("user", keyname, p, n-1, KEY_SPEC_USER_KEYRING);
+ serial = add_key("user", keyname, p, n, KEY_SPEC_USER_KEYRING);
memory_erase(p, n);
if (serial == -1)
return -errno;
diff --git a/src/test/test-strv.c b/src/test/test-strv.c
index f7a1217df7..841a36782f 100644
--- a/src/test/test-strv.c
+++ b/src/test/test-strv.c
@@ -647,7 +647,9 @@ static void test_strv_extend_n(void) {
static void test_strv_make_nulstr_one(char **l) {
_cleanup_free_ char *b = NULL, *c = NULL;
_cleanup_strv_free_ char **q = NULL;
+ const char *s = NULL;
size_t n, m;
+ unsigned i = 0;
assert_se(strv_make_nulstr(l, &b, &n) >= 0);
assert_se(q = strv_parse_nulstr(b, n));
@@ -656,6 +658,10 @@ static void test_strv_make_nulstr_one(char **l) {
assert_se(strv_make_nulstr(q, &c, &m) >= 0);
assert_se(m == n);
assert_se(memcmp(b, c, m) == 0);
+
+ NULSTR_FOREACH(s, b)
+ assert_se(streq(s, l[i++]));
+ assert_se(i == strv_length(l));
}
static void test_strv_make_nulstr(void) {