apparmor: dfa move character match into a macro

Signed-off-by: John Johansen <john.johansen@canonical.com>

1 files changed, 27 insertions, 47 deletions

diff --git a/security/apparmor/match.c b/security/apparmor/match.c
index 5d95caeddebc..aeac68c58689 100644
--- a/security/apparmor/match.c
+++ b/security/apparmor/match.c
@@ -329,6 +329,18 @@ fail:
         return ERR_PTR(error);
 }
 
+#define match_char(state, def, base, next, check, C)    \
+do {                                                    \
+        u32 b = (base)[(state)];                        \
+        unsigned int pos = base_idx(b) + (C);           \
+        if ((check)[pos] != (state)) {                  \
+                (state) = (def)[(state)];               \
+                break;                                  \
+        }                                               \
+        (state) = (next)[pos];                          \
+        break;                                          \
+} while (1)
+
 /**
  * aa_dfa_match_len - traverse @dfa to find state @str stops at
  * @dfa: the dfa to match @str against  (NOT NULL)
@@ -352,7 +364,7 @@ unsigned int aa_dfa_match_len(struct aa_dfa *dfa, unsigned int start,
         u32 *base = BASE_TABLE(dfa);
         u16 *next = NEXT_TABLE(dfa);
         u16 *check = CHECK_TABLE(dfa);
-        unsigned int state = start, pos;
+        unsigned int state = start;
 
         if (state == 0)
                 return 0;
@@ -361,23 +373,13 @@ unsigned int aa_dfa_match_len(struct aa_dfa *dfa, unsigned int start,
         if (dfa->tables[YYTD_ID_EC]) {
                 /* Equivalence class table defined */
                 u8 *equiv = EQUIV_TABLE(dfa);
-                /* default is direct to next state */
-                for (; len; len--) {
-                        pos = base_idx(base[state]) + equiv[(u8) *str++];
-                        if (check[pos] == state)
-                                state = next[pos];
-                        else
-                                state = def[state];
-                }
+                for (; len; len--)
+                        match_char(state, def, base, next, check,
+                                   equiv[(u8) *str++]);
         } else {
                 /* default is direct to next state */
-                for (; len; len--) {
-                        pos = base_idx(base[state]) + (u8) *str++;
-                        if (check[pos] == state)
-                                state = next[pos];
-                        else
-                                state = def[state];
-                }
+                for (; len; len--)
+                        match_char(state, def, base, next, check, (u8) *str++);
         }
 
         return state;
@@ -402,7 +404,7 @@ unsigned int aa_dfa_match(struct aa_dfa *dfa, unsigned int start,
         u32 *base = BASE_TABLE(dfa);
         u16 *next = NEXT_TABLE(dfa);
         u16 *check = CHECK_TABLE(dfa);
-        unsigned int state = start, pos;
+        unsigned int state = start;
 
         if (state == 0)
                 return 0;
@@ -412,22 +414,13 @@ unsigned int aa_dfa_match(struct aa_dfa *dfa, unsigned int start,
                 /* Equivalence class table defined */
                 u8 *equiv = EQUIV_TABLE(dfa);
                 /* default is direct to next state */
-                while (*str) {
-                        pos = base_idx(base[state]) + equiv[(u8) *str++];
-                        if (check[pos] == state)
-                                state = next[pos];
-                        else
-                                state = def[state];
-                }
+                while (*str)
+                        match_char(state, def, base, next, check,
+                                   equiv[(u8) *str++]);
         } else {
                 /* default is direct to next state */
-                while (*str) {
-                        pos = base_idx(base[state]) + (u8) *str++;
-                        if (check[pos] == state)
-                                state = next[pos];
-                        else
-                                state = def[state];
-                }
+                while (*str)
+                        match_char(state, def, base, next, check, (u8) *str++);
         }
 
         return state;
@@ -450,27 +443,14 @@ unsigned int aa_dfa_next(struct aa_dfa *dfa, unsigned int state,
         u32 *base = BASE_TABLE(dfa);
         u16 *next = NEXT_TABLE(dfa);
         u16 *check = CHECK_TABLE(dfa);
-        unsigned int pos;
 
         /* current state is <state>, matching character *str */
         if (dfa->tables[YYTD_ID_EC]) {
                 /* Equivalence class table defined */
                 u8 *equiv = EQUIV_TABLE(dfa);
-                /* default is direct to next state */
-
-                pos = base_idx(base[state]) + equiv[(u8) c];
-                if (check[pos] == state)
-                        state = next[pos];
-                else
-                        state = def[state];
-        } else {
-                /* default is direct to next state */
-                pos = base_idx(base[state]) + (u8) c;
-                if (check[pos] == state)
-                        state = next[pos];
-                else
-                        state = def[state];
-        }
+                match_char(state, def, base, next, check, equiv[(u8) c]);
+        } else
+                match_char(state, def, base, next, check, (u8) c);
 
         return state;
 }