io-stats: dump io-stats info in /var/run/gluster

It wouldn't make sense to allow iostats file to be written in
*any* directory. While the formating makes sure we try to append
io-stats-name for the file, so overwriting existing file is slim,
but in any case it makes sense to restrict dumping to one directory.

Below are the sample commands, and files created for the corresponding
values:

 $ setfattr -n trusted.io-stats-dump -v file-for-dump $M0

In this case, the file would be in /var/run/gluster/file-for-dump

 $ setfattr -n trusted.io-stats-dump -v /dir1/dir2/file-for-dump $M0

In this case, then the dump file is in /var/run/gluster/dir1-dir2-file-for-dump

Note that the value passed for this virtual xattr would be treated as a
file, and even if the value has '/' in it, it would be changed to '-'
for sanity.

Fixes: bz#1625106

Change-Id: Id9ae6a40a190b8937c51662e6e1c2a0f6c86a0e0
Signed-off-by: Amar Tumballi <amarts@redhat.com>

1 files changed, 25 insertions, 9 deletions

diff --git a/xlators/debug/io-stats/src/io-stats.c b/xlators/debug/io-stats/src/io-stats.c
index 6ddad96d8aa..123c3436dcf 100644
--- a/xlators/debug/io-stats/src/io-stats.c
+++ b/xlators/debug/io-stats/src/io-stats.c
@@ -46,6 +46,8 @@
 #define DEFAULT_GRP_BUF_SZ 16384
 #define IOS_BLOCK_COUNT_SIZE 32
 
+#define IOS_STATS_DUMP_DIR DEFAULT_VAR_RUN_DIRECTORY
+
 typedef enum {
         IOS_STATS_TYPE_NONE,
         IOS_STATS_TYPE_OPEN,
@@ -3062,7 +3064,6 @@ io_stats_fsync (call_frame_t *frame, xlator_t *this,
         return 0;
 }
 
-
 int
 conditional_dump (dict_t *dict, char *key, data_t *value, void *data)
 {
@@ -3075,9 +3076,10 @@ conditional_dump (dict_t *dict, char *key, data_t *value, void *data)
         char                 *filename = NULL;
         FILE                 *logfp = NULL;
         struct ios_dump_args args = {0};
-        int                   pid, namelen;
+        int                   pid, namelen, dirlen;
         char                  dump_key[100];
         char                 *slash_ptr = NULL;
+        char                 *path_in_value = NULL;
 
         stub  = data;
         this  = stub->this;
@@ -3086,16 +3088,30 @@ conditional_dump (dict_t *dict, char *key, data_t *value, void *data)
         name as well. This helps when there is more than a single io-stats
         instance in the graph, or the client and server processes are running
         on the same node */
-        /* hmmm... no check for this */
-        /* name format: <passed in path/filename>.<xlator name slashes to -> */
-        namelen = value->len + strlen (this->name) + 2; /* '.' and '\0' */
+        /* For the sanity of where the file should be located, we should make
+           sure file is written only inside RUNDIR (ie, /var/run/gluster) */
+        /* TODO: provide an option to dump it to different directory of
+           choice, based on options */
+        /* name format: /var/run/gluster/<passed in path/filename>.<xlator name slashes to -> */
+
+        path_in_value = data_to_str (value);
+
+        if (strstr (path_in_value, "../")) {
+                gf_log (this->name, GF_LOG_ERROR,
+                        "%s: no \"../\" allowed in path", path_in_value);
+                return -1;
+        }
+        dirlen = strlen (IOS_STATS_DUMP_DIR);
+        namelen = (dirlen + value->len + strlen (this->name) + 3);
+        /* +3 for '/', '.' and '\0' added in snprintf below*/
+
         filename = alloca0 (namelen);
-        memcpy (filename, data_to_str (value), value->len);
-        memcpy (filename + value->len, ".", 1);
-        memcpy (filename + value->len + 1, this->name, strlen(this->name));
+
+        snprintf (filename, namelen, "%s/%s.%s", IOS_STATS_DUMP_DIR,
+                  path_in_value, this->name);
 
         /* convert any slashes to '-' so that fopen works correctly */
-        slash_ptr = strchr (filename + value->len + 1, '/');
+        slash_ptr = strchr (filename + dirlen + 1, '/');
         while (slash_ptr) {
                 *slash_ptr = '-';
                 slash_ptr = strchr (slash_ptr, '/');