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-rw-r--r--src/slibc-human/machinemode.c239
1 files changed, 171 insertions, 68 deletions
diff --git a/src/slibc-human/machinemode.c b/src/slibc-human/machinemode.c
index 06029d3..f454613 100644
--- a/src/slibc-human/machinemode.c
+++ b/src/slibc-human/machinemode.c
@@ -24,6 +24,173 @@
/**
+ * Owner can execute/list or/and set UID.
+ */
+#define S_ISUSR (S_ISUID | S_IXUSR)
+
+/**
+ * Group can execute/list or/and set GID.
+ */
+#define S_ISGRP (S_ISGID | S_IXGRO)
+
+/**
+ * Others (not in group) can execute/list or/and sticky bit.
+ */
+#define S_ISOTH (S_ISVTX | S_IXOTH)
+
+
+/**
+ * Store permission bits.
+ *
+ * @param V:mode_t The variables for the permissions.
+ * @param U:int type First-level index in `bits` for the user.
+ * @param T:int type Second-level index in `bits` for bits to verify are unset.
+ * @param S:int type Second-level index in `bits` for bits to set.
+ */
+#define BITS_(V, U, T, S) if ((V) & bits[U][T]) goto invalid; else V |= bits[U][S]
+
+/**
+ * Store permission bits.
+ *
+ * @parma S:char Character representing the bits to set.
+ * @param V:mode_t The variables for the permissions.
+ * @param U:int type First-level index in `bits` for the user.
+ */
+#define BITS(S, V, U) \
+ if ((S) == 'r') { BITS_(V, U, 0, 0); } \
+ else if ((S) == 'w') { BITS_(V, U, 1, 1); } \
+ else if ((S) == 'x') { BITS_(V, U, 3, 2); } \
+ else if ((S) == 's') { BITS_(V, U, 3, 3); } \
+ else if ((S) == 't') { BITS_(V, U, 3, 3); } \
+ else if ((S) == 'S') { BITS_(V, U, 3, 4); } \
+ else if ((S) == 'T') { BITS_(V, U, 3, 4); } \
+ else if ((S) != '-') goto invalid
+
+
+
+/**
+ * User {0=owner. 1=group, 2=others} to permissions {0=can read,
+ * 1=can write, 2=can execute/list, 3=can execute/list or/and
+ * special, 4=special} to permissions bits map.
+ */
+static mode_t bits[][] = {
+ {S_IRUSR, S_IWUSR, S_IXUSR, S_ISUSR, S_ISUID},
+ {S_IRGRP, S_IWGRP, S_IXGRP, S_ISGRP, S_ISGID},
+ {S_IROTH, S_IWOTH, S_IXOTH, S_ISOTH, S_ISVTX},
+};
+
+
+/**
+ * Parse a symbolic file permission string with partial update.
+ *
+ * @param mode Output parameter for the bits to set, may be `NULL`.
+ * @param mask Output parameter for the bits to update, may be `NULL`.
+ * @param str The file permission to parse, must not include file type or be `NULL`.
+ * @return Zero on success, -1 on error.
+ *
+ * @throws EINVAL If `str` is not parseable.
+ */
+static inline int partial_symbolic(mode_t* restrict mode, mode_t* restrict mask, const char* restrict str)
+{
+#define TEST_(S, T, V) (strstarts(str, S) && !(T & (symbols = V)))
+#define TEST(S, T) (TEST_(S"+", T, 1) || TEST_(S"-", T, 2) || TEST_(S"=", T, 3))
+#define TESTV(T) (TEST(#T, T) ? (T |= symbols) : 0)
+
+ int u = 0, g = 0, o = 0, symbols, first, user, last;
+ mode_t or = 0, andn = 0, partial_or;
+ char symbol;
+
+ for (; *str; str++)
+ {
+ /* Check a/u/g/o and =/+/-. */
+ if (TEST("a", u|g|o)) first = 3, u |= symbols, g |= symbols, o |= symbols;
+ else if (TESTV(u)) first = 0;
+ else if (TESTV(g)) first = 1;
+ else if (TESTV(o)) first = 2;
+ else
+ goto invalid;
+
+ /* Get range of effected users. */
+ if (first < 3) last = first + 1;
+ else last = first, first = 0;
+
+ /* Get =/+/- and jump to permissions. */
+ symbol = str[1], str += 2;
+
+ /* Get permissions. */
+ for (partial_or = 0; *str && (*str != ','); str++)
+ for (user = first; user < last; user++)
+ BITS(*str, partial_or, j);
+
+ /* Apply permissions. */
+ if (symbol != '-') or |= partial_or;
+ if (symbol != '=') andn |= partial_or;
+ else
+ for (user = first; user < last; user++)
+ andn |= bits[user][0] | bits[user][1] | bits[user][3];
+ }
+
+ if (mode) *mode = or;
+ if (mask) *mask = andn;
+ return 0;
+ invalid:
+ return errno = EINVAL, -1;
+}
+
+
+/**
+ * Parse a full symbolic file permission string.
+ *
+ * @param mode Output parameter for the bits to set, may be `NULL`.
+ * @param mask Output parameter for the bits to update, may be `NULL`.
+ * @param str The file permission to parse, must not include file type or be `NULL`.
+ * @return Zero on success, -1 on error.
+ *
+ * @throws EINVAL If `str` is not parseable.
+ */
+static inline int exact_symbolic(mode_t* restrict mode, mode_t* restrict mask, const char* restrict str)
+{
+ mode_t or = 0;
+ long int user, perm;
+
+ for (user = 0; user < 3; user++)
+ for (perm = 0; perm < 3; perm++, str++)
+ BITS(*str, or, user);
+
+ if (mode) *mode = or;
+ if (mask) *mask = 07777;
+ return 0;
+ invalid:
+ return errno = EINVAL, -1;
+}
+
+
+/**
+ * Parse a numeric file permission string.
+ *
+ * @param mode Output parameter for the bits to set, may be `NULL`.
+ * @param mask Output parameter for the bits to update, may be `NULL`.
+ * @param str The file permission to parse, must not include file type or be `NULL`.
+ * @return Zero on success, -1 on error.
+ *
+ * @throws EINVAL If `str` is not parseable.
+ */
+static inline int exact_numeric(mode_t* restrict mode, mode_t* restrict mask, const char* restrict str)
+{
+ mode_t or = 0;
+ char s;
+
+ for (; (s = *str); str++)
+ if (('0' > s) || (s > '7') || (or = (or << 3) | (s & 15), or > 07777))
+ return errno = EINVAL, -1;
+
+ if (mode) *mode = or;
+ if (mask) *mask = 07777;
+ return 0;
+}
+
+
+/**
* Parses a human representation of file permissions, and updates to file permissions.
*
* Assuming the current file permissions is `value`, and neither
@@ -40,84 +207,20 @@
*/
int machinemode(mode_t* restrict mode, mode_t* restrict mask, const char* restrict str)
{
-#define S_ISUSR (S_ISUID | S_IXUSR)
-#define S_ISGRP (S_ISGID | S_IXGRO)
-#define S_ISOTH (S_ISVTX | S_IXOTH)
-
-#define TEST_(S, T, V) (strstarts(str, S) && !(T & (v = V)))
-#define TEST(S, T) (TEST_(S"+", T, 1) || TEST_(S"-", T, 2) || TEST_(S"=", T, 3))
-#define TESTV(T) (TEST(#T, T) ? (T = v) : 0)
-
-#define BITS_(V, T, S) if (V & bits[i][T]) goto invalid; else V |= bits[i][S]
-#define BITS(V) \
- if (*str == 'r') { BITS_(V, 0, 0); } \
- else if (*str == 'w') { BITS_(V, 1, 1); } \
- else if (*str == 'x') { BITS_(V, 3, 2); } \
- else if (*str == 's') { BITS_(V, 3, 3); } \
- else if (*str == 't') { BITS_(V, 3, 3); } \
- else if (*str == 'S') { BITS_(V, 3, 4); } \
- else if (*str == 'T') { BITS_(V, 3, 4); } \
- else if (*str != '-') goto invalid
-
- int i, j, n, u = 0, g = 0, o = 0, v;
- char s;
- mode_t or = 0, andn = 0, part;
- mode_t bits[][] = {
- {S_IRUSR, S_IWUSR, S_IXUSR, S_ISUSR, S_ISUID},
- {S_IRGRP, S_IWGRP, S_IXGRP, S_ISGRP, S_ISGID},
- {S_IROTH, S_IWOTH, S_IXOTH, S_ISOTH, S_ISVTX},
- };
-
switch (*str)
{
case '\0':
- goto invalid;
+ return errno = EINVAL, -1;
case 'a': case 'u': case 'g': case 'o':
- /* Partial, symbolic. */
- for (; *str; str++)
- {
- if (TEST("a", u|g|o)) i = 3, u |= v, g |= v, o |= v;
- else if (TESTV(u)) i = 0;
- else if (TESTV(g)) i = 1;
- else if (TESTV(o)) i = 2;
- else
- goto invalid;
- if (n < 3) n = i + 1;
- else n = i, i = 0;
- s = str[1], str += 2;
- for (part = 0; *str && (*str != ','); str++)
- for (j = i; j < n; j++)
- BITS(part);
- if (s != '-') or |= part;
- if (s != '=') andn |= part;
- else
- for (j = i; j < n; j++)
- andn |= bits[i][0] | bits[i][1] | bits[i][3];
- }
- break;
+ return partial_symbolic(mode, mask, str);
case 'r': case 'w': case 'x': case '-':
case 's': case 'S': case 't': case 'T':
- /* Exact, symbolic. */
- for (andn = 07777, i = 0; i < 3; i++)
- for (j = 0; j < 3; j++, str++)
- BITS(or);
- break;
+ return exact_symbolic(mode, mask, str);
default:
- /* Exact, numeric. */
- for (andn = 07777; (s = *str); str++)
- if (('0' > s) || (s > '7') || (or = (or << 3) | (s & 15), or > 07777))
- goto invalid;
- break;
+ return exact_numeric(mode, mask, str);
}
-
- if (mode) *mode = or;
- if (mask) *mask = andn;
- return 0;
-
- invalid:
- return errno = EINVAL, -1;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-11 22:35:22 +0000