[PATCH] tomoyo: automatically use patterns for several situations in learning mode

[Tetsuo Handa]

The "file_pattern" keyword was used for automatically recording patternized
pathnames when using the learning mode. This keyword was removed in TOMOYO
2.4 because it is impossible to predefine all possible pathname patterns.

However, since the numeric part of proc:/$PID/ , pipe:[$INO] and
socket:[$INO] has no meaning except $PID == 1, automatically replacing
the numeric part with \$ pattern helps reducing frequency of restarting
the learning mode due to hitting the quota.

Since replacing one digit with \$ pattern requires enlarging string buffer,
and several programs access only $PID == 1, replace only two or more digits
with \$ pattern.

Signed-off-by: Tetsuo Handa <penguin-kernel at I-love.SAKURA.ne.jp>
---
 security/tomoyo/common.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index 972664962e8f..dd7eb60da2e9 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -2024,6 +2024,32 @@ static void tomoyo_add_entry(struct tomoyo_domain_info *domain, char *header)
 	if (!buffer)
 		return;
 	snprintf(buffer, len - 1, "%s", cp);
+	if (*cp == 'f') {
+		/* Automatically replace 2 or more digits with \$ pattern. */
+		char *cp2;
+
+		/* e.g. file read proc:/$PID/stat */
+		cp = strstr(buffer, " proc:/");
+		if (cp && simple_strtoul(cp + 7, &cp2, 10) >= 10 && *cp2 == '/') {
+			*(cp + 7) = '\\';
+			*(cp + 8) = '$';
+			memmove(cp + 9, cp2, strlen(cp2) + 1);
+		}
+		/* e.g. file ioctl pipe:[$INO] $CMD */
+		cp = strstr(buffer, " pipe:[");
+		if (cp && simple_strtoul(cp + 7, &cp2, 10) >= 10 && *cp2 == ']') {
+			*(cp + 7) = '\\';
+			*(cp + 8) = '$';
+			memmove(cp + 9, cp2, strlen(cp2) + 1);
+		}
+		/* e.g. file ioctl socket:[$INO] $CMD */
+		cp = strstr(buffer, " socket:[");
+		if (cp && simple_strtoul(cp + 9, &cp2, 10) >= 10 && *cp2 == ']') {
+			*(cp + 9) = '\\';
+			*(cp + 10) = '$';
+			memmove(cp + 11, cp2, strlen(cp2) + 1);
+		}
+	}
 	if (realpath)
 		tomoyo_addprintf(buffer, len, " exec.%s", realpath);
 	if (argv0)
-- 
2.43.5