1 files changed, 73 insertions, 5 deletions

diff --git a/src/main.c b/src/main.c
index 204fc69..53f8e80 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,6 +2,9 @@
 #include <assert.h>
 #include <string.h>
 #include <errno.h>
+#include <grp.h>
+#include <pwd.h>
+#include <sys/types.h>
 
 #include <libdaemon/dlog.h>
 #include <libdaemon/dfork.h>
@@ -15,9 +18,14 @@
 
 oop_source* event_source = NULL;
 struct gengetopt_args_info args;
-const char *appname = NULL, *username = NULL;
+const char *appname = NULL;
+
+uid_t target_uid = 0;
+gid_t target_gid = 0;
 
 #define DEFAULT_MSNTABLE "../conf/msntab"
+#define IVAM_USER "ivam"
+#define IVAM_GROUP "ivam"
 
 static void *oop_exit_cb(oop_source *source, int sig, void *user) {
     daemon_log(LOG_ERR, "Recieved signal %s", sig == SIGINT ? "SIGINT" : (sig == SIGTERM ? "SIGTERM" : "UNKNWON"));
@@ -42,11 +50,66 @@ static void *oop_dump_cb(oop_source *source, int sig, void *user) {
 }
 
 
+static int change_uid_gid(void) {
+    if (args.no_drop_root_flag)
+        return 0;
+        
+    if (initgroups(IVAM_USER, target_gid) != 0) {
+        daemon_log(LOG_ERR, "Failed to change group list: %s", strerror(errno));
+        return -1;
+    }
+    
+    if (setgid(target_gid) != 0) {
+        daemon_log(LOG_ERR, "Failed to change GID: %s", strerror(errno));
+        return -1;
+    }
+    
+    if (setuid(target_uid) != 0) {
+        daemon_log(LOG_ERR, "Failed to change UID: %s", strerror(errno));
+        return -1;
+    }
+
+    daemon_log(LOG_INFO, "Successfully dropped root privileges.");
+    
+    return 0;
+}
+
+static int get_target_uid_gid(void) {
+    struct passwd *pw;
+    struct group * gr;
+
+    if (args.no_drop_root_flag) {
+        target_uid = getuid();
+        target_gid = getgid();
+        return 0;
+    }
+
+    if (!(pw = getpwnam(IVAM_USER))) {
+        daemon_log(LOG_ERR, "Failed to find user '%s'.", IVAM_USER);
+        return -1;
+    }
+
+    if (!(gr = getgrnam(IVAM_GROUP))) {
+        daemon_log(LOG_ERR, "Failed to find group '%s'.", IVAM_GROUP);
+        return -1;
+    }
+
+    target_uid = pw->pw_uid;
+    target_gid = gr->gr_gid;
+    
+    daemon_log(LOG_INFO, "Found user '%s' (UID %lu) and group '%s' (GID %lu).", IVAM_USER, (unsigned long) target_uid, IVAM_GROUP, (unsigned long) target_gid);
+
+    return 0;
+}
+
 int main_loop(void) {
     int r = -1, retval_sent = 0;
     oop_source_sys *sys = NULL;
 
     daemon_log(LOG_INFO, "Starting up.");
+
+    if (get_target_uid_gid() < 0)
+        goto finish;
     
     if (!(sys = oop_sys_new())) {
         daemon_log(LOG_ERR, "Failed to create system source.");
@@ -55,6 +118,12 @@ int main_loop(void) {
 
     event_source = oop_sys_source(sys);
     assert(event_source);
+    
+    if (modem_manager_init(args.channels_arg) < 0)
+        goto finish;
+
+    if (change_uid_gid() < 0)
+        goto finish;
 
     if (child_process_init() < 0)
         goto finish;
@@ -62,9 +131,6 @@ int main_loop(void) {
     if (msntab_load(args.msntab_arg ? args.msntab_arg : DEFAULT_MSNTABLE) < 0)
         goto finish;
 
-    if (modem_manager_init(args.channels_arg) < 0)
-        goto finish;
-
     event_source->on_signal(event_source, SIGINT, oop_exit_cb, NULL);
     event_source->on_signal(event_source, SIGTERM, oop_exit_cb, NULL);
     event_source->on_signal(event_source, SIGHUP, oop_reload_cb, NULL);
@@ -177,7 +243,9 @@ int main(int argc, char*argv[]) {
 
     ret = main_loop() < 0 ? 1 : 0;
 
-    daemon_pid_file_remove();
+    if (daemon_pid_file_remove() < 0)
+        daemon_log(LOG_WARNING, "Failed to remove PID file (%s).", strerror(errno));
+
     return ret;
 }