>From ad3b28cbb1e78d1894d9f1e1780902d140316d42 Mon Sep 17 00:00:00 2001
From: John Johansen <[email protected]>
Date: Wed, 15 Jul 2015 05:36:32 -0700
Subject: [PATCH 1/4] Split aa_query_label into a base aa_query_cmd and it
 aa_query_label

Split the basic transaction file query out of aa_query_label so that
it can be reused by other query types.

Signed-off-by: John Johansen <[email protected]>
---
 libraries/libapparmor/doc/aa_query_label.pod  | 12 +++-
 libraries/libapparmor/include/sys/apparmor.h  |  2 +
 libraries/libapparmor/src/kernel.c            | 92 +++++++++++++++++++++------
 libraries/libapparmor/swig/SWIG/libapparmor.i |  2 +
 4 files changed, 84 insertions(+), 24 deletions(-)

diff --git a/libraries/libapparmor/doc/aa_query_label.pod 
b/libraries/libapparmor/doc/aa_query_label.pod
index 3e943a7..900e2d0 100644
--- a/libraries/libapparmor/doc/aa_query_label.pod
+++ b/libraries/libapparmor/doc/aa_query_label.pod
@@ -28,13 +28,16 @@ aa_query_label - query access permission associated with a 
label
 
 B<#include E<lt>sys/apparmor.hE<gt>>
 
-B<int aa_query_label((uint32_t mask, char *query, size_t size,
+B<int aa_query_cmd(const char *cmd, size_t cmd_size, char *query,
+               size_t size, char *buffer, size_t bsize);>
+
+B<int aa_query_label(uint32_t mask, char *query, size_t size,
                int *allowed, int *audited);>
 
-B<int aa_query_file_path((uint32_t mask, const char *label, size_t label_len,
+B<int aa_query_file_path(uint32_t mask, const char *label, size_t label_len,
                const char *path, int *allowed, int *audited);>
 
-B<int aa_query_file_path_len((uint32_t mask, const char *label,
+B<int aa_query_file_path_len(uint32_t mask, const char *label,
                size_t label_len, const char *path, size_t path_len,
                int *allowed, int *audited);>
 
@@ -51,6 +54,9 @@ Link with B<-lapparmor> when compiling.
 
 =head1 DESCRIPTION
 
+The aa_query_cmd function setup and does the raw query of the kernel. It is
+the basis of the other query_X functions.
+
 The aa_query_label function fetches the current permissions granted by the
 specified I<label> in the I<query> string.
 
diff --git a/libraries/libapparmor/include/sys/apparmor.h 
b/libraries/libapparmor/include/sys/apparmor.h
index 13a6a8c..61629bc 100644
--- a/libraries/libapparmor/include/sys/apparmor.h
+++ b/libraries/libapparmor/include/sys/apparmor.h
@@ -99,6 +99,8 @@ extern int aa_getpeercon(int fd, char **label, char **mode);
 #define AA_QUERY_CMD_LABEL             "label"
 #define AA_QUERY_CMD_LABEL_SIZE                sizeof(AA_QUERY_CMD_LABEL)
 
+extern int aa_query_cmd(const char *cmd, size_t cmd_size, char *query,
+                       size_t size, char *buffer, size_t bsize);
 extern int aa_query_label(uint32_t mask, char *query, size_t size, int *allow,
                          int *audit);
 extern int aa_query_file_path_len(uint32_t mask, const char *label,
diff --git a/libraries/libapparmor/src/kernel.c 
b/libraries/libapparmor/src/kernel.c
index a3f8efa..1de4e54 100644
--- a/libraries/libapparmor/src/kernel.c
+++ b/libraries/libapparmor/src/kernel.c
@@ -760,30 +760,22 @@ static void aafs_access_init_once(void)
        free(aafs);
 }
 
-/* "allow 0x00000000\ndeny 0x00000000\naudit 0x00000000\nquiet 0x00000000\n" */
-#define QUERY_LABEL_REPLY_LEN  67
-
 /**
- * aa_query_label - query the access(es) of a label
- * @mask: permission bits to query
- * @query: binary query string, must be offset by AA_QUERY_CMD_LABEL_SIZE
- * @size: size of the query string must include AA_QUERY_CMD_LABEL_SIZE
- * @allowed: upon successful return, will be 1 if query is allowed and 0 if not
- * @audited: upon successful return, will be 1 if query should be audited and 0
- *           if not
+ * aa_query_cmd_open - begin a query for labels @cmd info
+ * @cmd: query cmd to use
+ * @cmd_size: size of the cmd being used
+ * @query: binary query string, must be offset by @cmd_size
+ * @size: size of the query string must include @cmd_size
  *
- * Returns: 0 on success else -1 and sets errno. If -1 is returned and errno is
- *          ENOENT, the subject label in the query string is unknown to the
- *          kernel.
+ * Returns: fd with the query issued and results waiting to be read else -1 
and sets errno.
+ *          If -1 is returned and errno is ENOENT, the subject label in
+ *          the query string is unknown to the kernel.
  */
-int query_label(uint32_t mask, char *query, size_t size, int *allowed,
-               int *audited)
+static int aa_query_cmd_open(const char *cmd, size_t cmd_size, char *query, 
size_t size)
 {
-       char buf[QUERY_LABEL_REPLY_LEN];
-       uint32_t allow, deny, audit, quiet;
        int fd, ret, saved;
 
-       if (!mask || size <= AA_QUERY_CMD_LABEL_SIZE) {
+       if (size <= cmd_size) {
                errno = EINVAL;
                return -1;
        }
@@ -804,7 +796,7 @@ int query_label(uint32_t mask, char *query, size_t size, 
int *allowed,
                return -1;
        }
 
-       memcpy(query, AA_QUERY_CMD_LABEL, AA_QUERY_CMD_LABEL_SIZE);
+       memcpy(query, cmd, cmd_size);
        errno = 0;
        ret = write(fd, query, size);
        if (ret != size) {
@@ -818,10 +810,69 @@ int query_label(uint32_t mask, char *query, size_t size, 
int *allowed,
                return -1;
        }
 
-       ret = read(fd, buf, QUERY_LABEL_REPLY_LEN);
+       return fd;
+}
+
+/**
+ * aa_query_cmd - make a query for labels @cmd info
+ * @cmd: query cmd to use
+ * @cmd_size: size of the cmd being used
+ * @query: binary query string, must be offset by @cmd_size
+ * @size: size of the query string must include @cmd_size
+ * @buffer: buffer to return query data in
+ * @bsize: size of @buffer
+ *
+ * Returns: size of data read on success else -1 and sets errno.
+ *          If -1 is returned and errno is ENOENT, the subject label in
+ *          the query string is unknown to the kernel.
+ */
+int aa_query_cmd(const char *cmd, size_t cmd_size, char *query, size_t size,
+                char *buffer, size_t bsize)
+{
+       int fd, ret, saved;
+
+       fd = aa_query_cmd_open(cmd, cmd_size, query, size);
+       if (fd == -1)
+               return -1;
+
+       ret = read(fd, buffer, bsize);
        saved = errno;
        (void)close(fd);
        errno = saved;
+
+       return ret;
+}
+
+/* "allow 0x00000000\ndeny 0x00000000\naudit 0x00000000\nquiet 0x00000000\n" */
+#define QUERY_LABEL_REPLY_LEN  67
+
+/**
+ * aa_query_label - query the access(es) of a label
+ * @mask: permission bits to query
+ * @query: binary query string, must be offset by AA_QUERY_CMD_LABEL_SIZE
+ * @size: size of the query string must include AA_QUERY_CMD_LABEL_SIZE
+ * @allowed: upon successful return, will be 1 if query is allowed and 0 if not
+ * @audited: upon successful return, will be 1 if query should be audited and 0
+ *           if not
+ *
+ * Returns: 0 on success else -1 and sets errno. If -1 is returned and errno is
+ *          ENOENT, the subject label in the query string is unknown to the
+ *          kernel.
+ */
+int query_label(uint32_t mask, char *query, size_t size, int *allowed,
+               int *audited)
+{
+       char buf[QUERY_LABEL_REPLY_LEN];
+       uint32_t allow, deny, audit, quiet;
+       int ret;
+
+       if (!mask) {
+               errno = EINVAL;
+               return -1;
+       }
+
+       ret = aa_query_cmd(AA_QUERY_CMD_LABEL, AA_QUERY_CMD_LABEL_SIZE, query,
+                          size, buf, QUERY_LABEL_REPLY_LEN);
        if (ret != QUERY_LABEL_REPLY_LEN) {
                errno = EPROTO;
                return -1;
@@ -928,7 +979,6 @@ int aa_query_link_path_len(const char *label, size_t 
label_len,
                           int *allowed, int *audited)
 {
        autofree char *query = NULL;
-       int rc;
 
        /* + 1 for null separators */
        size_t size = AA_QUERY_CMD_LABEL_SIZE + label_len + 1 + target_len +
diff --git a/libraries/libapparmor/swig/SWIG/libapparmor.i 
b/libraries/libapparmor/swig/SWIG/libapparmor.i
index 69b4cc2..3e1950a 100644
--- a/libraries/libapparmor/swig/SWIG/libapparmor.i
+++ b/libraries/libapparmor/swig/SWIG/libapparmor.i
@@ -55,6 +55,8 @@ extern int aa_gettaskcon(pid_t target, char **label, char 
**mode);
 extern int aa_getcon(char **label, char **mode);
 extern int aa_getpeercon_raw(int fd, char *buf, int *len, char **mode);
 extern int aa_getpeercon(int fd, char **label, char **mode);
+extern int aa_query_cmd(const char *cmd, size_t cmd_size, char *query,
+                       size_t size, char *buffer, size_t bsize);
 extern int aa_query_label(uint32_t mask, char *query, size_t size, int *allow,
                          int *audit);
 extern int aa_query_file_path_len(uint32_t mask, const char *label,
-- 
2.1.4



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