system-controller: try to get launching user for an app using ail and pid.

With the latest ail we need to retreive the launching user for an app
using the PID to get the category right. If the user  is not found this
way, we consider the default user ('app') as the launching user and fall
back to look up and use the UID of that instead.

Change-Id: Iaa1d9091598cd7b28dff0ee67e67d357325f152d
Signed-off-by: Baptiste DURAND <baptiste.durand@open.eurogiciel.org>

diff --git a/src/plugins/system-controller/application-tracker/application-tracker.c b/src/plugins/system-controller/application-tracker/application-tracker.c
index c863f93..16fbd18 100644 (file)
--- a/src/plugins/system-controller/application-tracker/application-tracker.c
+++ b/src/plugins/system-controller/application-tracker/application-tracker.c
@@ -33,6 +33,10 @@
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
+#include <unistd.h>
+#include <pwd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
 
 #include <murphy/common.h>
 
@@ -45,6 +49,10 @@
 
 #define AUL_APPLICATION_TABLE_NAME "aul_applications"
 #define DB_BUF_SIZE 1024
+#define MAX_CMD_BUFSZ 1024
+
+#define DEFAULT_USER "app"
+#define DEFAULT_UID  5000
 
 /* IMPORTANT: You need to have glib plugin loaded in order for this to work! */
 
@@ -111,10 +119,12 @@ static int add_app_to_db(const char *appid, pid_t pid, const char *category)
     return 0;
 }
 
-static ail_cb_ret_e handle_appinfo(const ail_appinfo_h appinfo, void *user_data)
+static ail_cb_ret_e handle_appinfo(const ail_appinfo_h appinfo,
+                                   void *user_data, uid_t uid)
 {
     char *val = NULL;
     char **str = user_data;
+    MRP_UNUSED(uid);
 
     ail_appinfo_get_str(appinfo, AIL_PROP_CATEGORIES_STR, &val);
 
@@ -128,7 +138,7 @@ static ail_cb_ret_e handle_appinfo(const ail_appinfo_h appinfo, void *user_data)
     return AIL_CB_RET_CANCEL;
 }
 
-static char *get_category(const char *appid)
+static char *get_category(const char *appid, uid_t uid)
 {
     ail_error_e e;
     char *value = NULL;
@@ -146,7 +156,7 @@ static char *get_category(const char *appid)
     if (e != AIL_ERROR_OK)
         goto end;
 
-    e = ail_filter_list_appinfo_foreach(f, handle_appinfo, &value);
+    e = ail_filter_list_usr_appinfo_foreach(f, handle_appinfo, &value, uid);
     if (e != AIL_ERROR_OK)
         goto end;
 
@@ -155,10 +165,46 @@ end:
     return value;
 }
 
+uid_t get_usr_by_pid(int pid)
+{
+    char buf[MAX_CMD_BUFSZ];
+    int ret;
+    uid_t uid;
+    struct stat dirstat;
+    snprintf(buf, sizeof(buf), "/proc/%d", pid);
+    ret = stat(buf, &dirstat);
+    if (ret < 0)
+        uid = (uid_t)-1;
+    else
+        uid = dirstat.st_uid;
+    return uid;
+}
+
+
+static int get_default_usr(void)
+{
+    static uid_t uid = 0;
+    struct passwd *pwd;
+
+    if (uid != 0)
+        return uid;
+
+    if ((pwd = getpwnam(DEFAULT_USER)) != NULL)
+        uid = pwd->pw_uid;
+    else
+        uid = DEFAULT_UID;
+
+    mrp_log_info("User '%s' resolved to UID %d.", DEFAULT_USER, uid);
+
+    return uid;
+}
+
+
 static int aul_launch_signal(int pid, void *user_data)
 {
     char appid[512];
     char *category;
+    uid_t uid;
 
     MRP_UNUSED(user_data);
 
@@ -166,11 +212,17 @@ static int aul_launch_signal(int pid, void *user_data)
 
     mrp_log_info("tracker: launched app %i", pid);
 
-    if (aul_app_get_appid_bypid(pid, appid, 511) < 0) {
+    if (aul_app_get_appid_bypid(pid, appid, sizeof(appid) - 1) < 0) {
         appid[0] = '\0';
     }
 
-    category = get_category(appid);
+    uid = get_usr_by_pid(pid);
+    if(uid == (uid_t)-1) {
+        uid = get_default_usr();
+        mrp_log_info("Unable to get launching user for process %i, "
+                     "falling back to '%s' (%d).", pid, DEFAULT_USER, uid);
+    }
+    category = get_category(appid, uid);
 
     add_app_to_db(appid, pid, category);
 
@@ -182,13 +234,19 @@ static int aul_launch_signal(int pid, void *user_data)
 static int aul_iter_app_info(const aul_app_info *ai, void *user_data)
 {
     char *category;
-
+    uid_t uid;
     MRP_UNUSED(user_data);
 
     mrp_log_info("tracker: app info pid %i, appid: %s, pkg_name %s", ai->pid,
             ai->appid ? ai->appid : "NULL", ai->pkg_name);
 
-    category = get_category(ai->appid);
+    uid = get_usr_by_pid(ai->pid);
+    if(uid == (uid_t)-1) {
+        uid = get_default_usr();
+        mrp_log_info("Unable to get launching user for process %i, "
+                     "falling back to '%s' (%d).", ai->pid, DEFAULT_USER, uid);
+    }
+    category = get_category(ai->appid, uid);
 
     add_app_to_db(ai->appid, ai->pid, category);