Allow tracing group users to read trace files they generated

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/ltt-sessiond/main.c b/ltt-sessiond/main.c
index 1e2a0831dc80187b4b581e72ef97a037762a3fa4..d104830667dd6cf9efc040584a5c18c4293381c9 100644 (file)
--- a/ltt-sessiond/main.c
+++ b/ltt-sessiond/main.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -114,6 +115,20 @@ static int modprobe_remove_kernel_modules(void);
  */
 static struct ltt_session_list *session_list_ptr;
 
+static gid_t allowed_group(void)
+{
+       struct group *grp;
+
+       grp = (opt_tracing_group != NULL) ?
+               (grp = getgrnam(opt_tracing_group)) :
+               (grp = getgrnam(default_tracing_group));
+       if (!grp) {
+               return -1;
+       } else {
+               return grp->gr_gid;
+       }
+}
+
 /*
  * Init quit pipe.
  *
@@ -1045,7 +1060,7 @@ static int mount_debugfs(char *path)
        int ret;
        char *type = "debugfs";
 
-       ret = mkdir_recursive(path, S_IRWXU | S_IRWXG);
+       ret = mkdir_recursive(path, S_IRWXU | S_IRWXG, geteuid(), getegid());
        if (ret < 0) {
                goto error;
        }
@@ -1226,9 +1241,10 @@ static int create_kernel_session(struct ltt_session *session)
                goto error;
        }
 
-       ret = mkdir_recursive(session->path, S_IRWXU | S_IRWXG );
+       ret = mkdir_recursive(session->path, S_IRWXU | S_IRWXG,
+                             geteuid(), allowed_group()); 
        if (ret < 0) {
-               if (ret != EEXIST) {
+               if (ret != -EEXIST) {
                        ERR("Trace directory creation error");
                        goto error;
                }
@@ -2445,13 +2461,10 @@ static int set_permissions(void)
 {
        int ret;
        struct group *grp;
+       gid_t gid;
 
-       /* Decide which group name to use */
-       (opt_tracing_group != NULL) ?
-               (grp = getgrnam(opt_tracing_group)) :
-               (grp = getgrnam(default_tracing_group));
-
-       if (grp == NULL) {
+       gid = allowed_group();
+       if (gid < 0) {
                if (is_root) {
                        WARN("No tracing group detected");
                        ret = 0;
@@ -2463,21 +2476,21 @@ static int set_permissions(void)
        }
 
        /* Set lttng run dir */
-       ret = chown(LTTNG_RUNDIR, 0, grp->gr_gid);
+       ret = chown(LTTNG_RUNDIR, 0, gid);
        if (ret < 0) {
                ERR("Unable to set group on " LTTNG_RUNDIR);
                perror("chown");
        }
 
        /* lttng client socket path */
-       ret = chown(client_unix_sock_path, 0, grp->gr_gid);
+       ret = chown(client_unix_sock_path, 0, gid);
        if (ret < 0) {
                ERR("Unable to set group on %s", client_unix_sock_path);
                perror("chown");
        }
 
        /* kconsumerd error socket path */
-       ret = chown(kconsumerd_err_unix_sock_path, 0, grp->gr_gid);
+       ret = chown(kconsumerd_err_unix_sock_path, 0, gid);
        if (ret < 0) {
                ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path);
                perror("chown");

diff --git a/ltt-sessiond/utils.c b/ltt-sessiond/utils.c
index ff36ab187141e126dcfb1c720cdbe9083c26860b..5b8e31b8d0b4e44623360fa68fa67288ba4a923d 100644 (file)
--- a/ltt-sessiond/utils.c
+++ b/ltt-sessiond/utils.c
@@ -1,5 +1,6 @@
 /*
- * Copyright (C)  2011 - David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -44,7 +45,7 @@ const char *get_home_dir(void)
  *
  *  Create recursively directory using the FULL path.
  */
-int mkdir_recursive(const char *path, mode_t mode)
+int mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid)
 {
        int ret;
        char *p, tmp[PATH_MAX];
@@ -70,7 +71,19 @@ int mkdir_recursive(const char *path, mode_t mode)
                        if (ret < 0) {
                                if (!(errno == EEXIST)) {
                                        perror("mkdir recursive");
-                                       ret = errno;
+                                       ret = -errno;
+                                       goto umask_error;
+                               }
+                       } else if (ret == 0) {
+                               /*
+                                * We created the directory. Set its
+                                * ownership to the user/group
+                                * specified.
+                                */
+                               ret = chown(tmp, uid, gid);
+                               if (ret < 0) {
+                                       perror("chown in mkdir recursive");
+                                       ret = -errno;
                                        goto umask_error;
                                }
                        }
@@ -80,7 +93,18 @@ int mkdir_recursive(const char *path, mode_t mode)
 
        ret = mkdir(tmp, mode);
        if (ret < 0) {
-               ret = errno;
+               ret = -errno;
+       } else if (ret == 0) {
+               /*
+                * We created the directory. Set its ownership to the
+                * user/group specified.
+                */
+               ret = chown(tmp, uid, gid);
+               if (ret < 0) {
+                       perror("chown in mkdir recursive");
+                       ret = -errno;
+                       goto umask_error;
+               }
        }
 
 umask_error:

diff --git a/ltt-sessiond/utils.h b/ltt-sessiond/utils.h
index d451eb63a668b023f342affdf6cf128a63317150..41aad2557b0786c75f0646ebfd88dd2473ab0317 100644 (file)
--- a/ltt-sessiond/utils.h
+++ b/ltt-sessiond/utils.h
@@ -1,5 +1,9 @@
+#ifndef _LTT_UTILS_H
+#define _LTT_UTILS_H
+
 /*
  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -16,14 +20,13 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
 
-#ifndef _LTT_UTILS_H
-#define _LTT_UTILS_H
+#include <unistd.h>
 
 #ifndef ARRAY_SIZE
 #define ARRAY_SIZE(array)      (sizeof(array) / (sizeof((array)[0])))
 #endif
 
-int mkdir_recursive(const char *path, mode_t mode);
+int mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid);
 const char *get_home_dir(void);
 
 #endif /* _LTT_UTILS_H */