asterisk.c: Use the euid's home directory to read/write cli history

The CLI .asterisk_history file is read from/written to the directory
specified by the HOME environment variable. If the root user starts
asterisk with the -U/-G options, or with runuser/rungroup set in
asterisk.conf, the asterisk process is started as root but then it
calls setuid/setgid to set the new user/group. This does NOT reset
the HOME environment variable to the new user's home directory
though so it's still left as "/root". In this case, the new user
will almost certainly NOT have access to read from or write to the
history file.

* Added function process_histfile() which calls
  getpwuid(geteuid()) and uses pw->dir as the home directory
  instead of the HOME environment variable.
* ast_el_read_default_histfile() and ast_el_write_default_histfile()
  have been modified to use the new process_histfile()
  function.

Resolves: #337

diff --git a/main/asterisk.c b/main/asterisk.c
index 51dfa9cc2379e469a8765515e9e4af26419997d1..650591d6ff4476ffc962bb5fd2bc5733093abb78 100644 (file)
--- a/main/asterisk.c
+++ b/main/asterisk.c
@@ -3173,26 +3173,41 @@ static int ast_el_read_history(const char *filename)
        return history(el_hist, &ev, H_LOAD, filename);
 }
 
-static void ast_el_read_default_histfile(void)
+static void process_histfile(int (*readwrite)(const char *filename))
 {
-       char histfile[80] = "";
-       const char *home = getenv("HOME");
+       struct passwd *pw = getpwuid(geteuid());
+       int ret = 0;
+       char *name = NULL;
 
-       if (!ast_strlen_zero(home)) {
-               snprintf(histfile, sizeof(histfile), "%s/.asterisk_history", home);
-               ast_el_read_history(histfile);
+       if (!pw || ast_strlen_zero(pw->pw_dir)) {
+               ast_log(LOG_ERROR, "Unable to determine home directory.  History read/write disabled.\n");
+               return;
        }
+
+       ret = ast_asprintf(&name, "%s/.asterisk_history", pw->pw_dir);
+       if (ret <= 0) {
+               ast_log(LOG_ERROR, "Unable to create history file name.  History read/write disabled.\n");
+               return;
+       }
+
+       ret = readwrite(name);
+       if (ret < 0) {
+               ast_log(LOG_ERROR, "Unable to read or write history file '%s'\n", name);
+       }
+
+       ast_free(name);
+
+       return;
 }
 
-static void ast_el_write_default_histfile(void)
+static void ast_el_read_default_histfile(void)
 {
-       char histfile[80] = "";
-       const char *home = getenv("HOME");
+       process_histfile(ast_el_read_history);
+}
 
-       if (!ast_strlen_zero(home)) {
-               snprintf(histfile, sizeof(histfile), "%s/.asterisk_history", home);
-               ast_el_write_history(histfile);
-       }
+static void ast_el_write_default_histfile(void)
+{
+       process_histfile(ast_el_write_history);
 }
 
 static void ast_remotecontrol(char *data)