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author | Lennart Poettering <lennart@poettering.net> | 2023-02-20 11:43:13 +0100 |
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committer | Lennart Poettering <lennart@poettering.net> | 2023-02-20 16:27:26 +0100 |
commit | c52c4d6974e3bc6d8ffdd3b73207617e06cd5157 (patch) | |
tree | 487a3aee5767979b21ec8246daed0ffde951b8e5 /src | |
parent | d0e67c69ba7fa9984a2d96caa8ad4b7762ed3160 (diff) | |
download | systemd-c52c4d6974e3bc6d8ffdd3b73207617e06cd5157.tar.gz |
cap-list: add CAPABILITY_TO_STRING() macro using compound initialization to allocate fallback buffer
Let's add a helper that can return a numeric string in case we don't
recognize a name for a capability.
Diffstat (limited to 'src')
-rw-r--r-- | src/basic/cap-list.c | 17 | ||||
-rw-r--r-- | src/basic/cap-list.h | 8 | ||||
-rw-r--r-- | src/test/test-cap-list.c | 9 |
3 files changed, 33 insertions, 1 deletions
diff --git a/src/basic/cap-list.c b/src/basic/cap-list.c index bcf7e597c2..7843efc994 100644 --- a/src/basic/cap-list.c +++ b/src/basic/cap-list.c @@ -19,13 +19,28 @@ static const struct capability_name* lookup_capability(register const char *str, const char *capability_to_name(int id) { if (id < 0) return NULL; - if ((size_t) id >= ELEMENTSOF(capability_names)) return NULL; return capability_names[id]; } +const char *capability_to_string(int id, char buf[static CAPABILITY_TO_STRING_MAX]) { + const char *p; + + if (id < 0) + return NULL; + if (id >= 63) /* refuse caps >= 63 since we can't store them in a uint64_t mask anymore, and still retain UINT64_MAX as marker for "unset" */ + return NULL; + + p = capability_to_name(id); + if (p) + return p; + + sprintf(buf, "0x%x", (unsigned) id); /* numerical fallback */ + return buf; +} + int capability_from_name(const char *name) { const struct capability_name *sc; int r, i; diff --git a/src/basic/cap-list.h b/src/basic/cap-list.h index 888e9223e7..bddadcbae5 100644 --- a/src/basic/cap-list.h +++ b/src/basic/cap-list.h @@ -3,7 +3,15 @@ #include <inttypes.h> +/* Space for capability_to_string() in case we write out a numeric capability because we don't know the name + * for it. "0x3e" is the largest string we might output, in both sensese of the word "largest": two chars for + * "0x", two bytes for the hex value, and one trailing NUL byte. */ +#define CAPABILITY_TO_STRING_MAX (2 + 2 + 1) + const char *capability_to_name(int id); +const char *capability_to_string(int id, char buf[static CAPABILITY_TO_STRING_MAX]); +#define CAPABILITY_TO_STRING(id) capability_to_string(id, (char[CAPABILITY_TO_STRING_MAX]) {}) + int capability_from_name(const char *name); int capability_list_length(void); diff --git a/src/test/test-cap-list.c b/src/test/test-cap-list.c index 517641a019..8df425bdd2 100644 --- a/src/test/test-cap-list.c +++ b/src/test/test-cap-list.c @@ -14,6 +14,13 @@ TEST(cap_list) { assert_se(!capability_to_name(-1)); assert_se(!capability_to_name(capability_list_length())); + assert_se(!capability_to_name(63)); + assert_se(!capability_to_name(64)); + + assert_se(!CAPABILITY_TO_STRING(-1)); + if (capability_list_length() <= 62) + assert_se(streq(CAPABILITY_TO_STRING(62), "0x3e")); + assert_se(!CAPABILITY_TO_STRING(64)); for (int i = 0; i < capability_list_length(); i++) { const char *n; @@ -21,6 +28,8 @@ TEST(cap_list) { assert_se(n = capability_to_name(i)); assert_se(capability_from_name(n) == i); printf("%s = %i\n", n, i); + + assert_se(streq(CAPABILITY_TO_STRING(i), n)); } assert_se(capability_from_name("asdfbsd") == -EINVAL); |