1 files changed, 116 insertions, 0 deletions
diff --git a/src/login.c b/src/login.c
new file mode 100644
index 0000000..5a97fb6
--- /dev/null
+++ b/src/login.c
@@ -0,0 +1,116 @@
+/**
+ * cerberus – Minimal login program
+ * 
+ * Copyright © 2013  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <pwd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "config.h"
+
+#include "login.h"
+
+
+/**
+ * The environment variables
+ */
+extern char** environ;
+
+
+/**
+ * Change directory to the user's home directory
+ * 
+ * @param  entry  The user entry in the password file
+ */
+void chdir_home(struct passwd* entry)
+{
+  if (chdir(entry->pw_dir))
+    {
+      perror("chdir");
+      if (chdir(DEFAULT_HOME))
+	{
+	  perror("chdir");
+	  sleep(ERROR_SLEEP);
+	  _exit(1);
+	}
+      entry->pw_dir = DEFAULT_HOME;
+    }
+}
+
+
+/**
+ * Make sure the shell to use is definied
+ * 
+ * @param  entry  The user entry in the password file
+ */
+void ensure_shell(struct passwd* entry)
+{
+  if ((entry->pw_shell && *(entry->pw_shell)) == 0)
+    entry->pw_shell = DEFAULT_SHELL;
+}
+
+
+/**
+ * Set environment variables
+ * 
+ * @param  entry         The user entry in the password file
+ * @param  preserve_env  Whether to preserve the environment
+ */
+void set_environ(struct passwd* entry, char preserve_env)
+{
+  char* _term = getenv("TERM");
+  char* term = NULL;
+  if (_term)
+    {
+      int n = 0, i;
+      while (*(_term + n++))
+	;
+      term = malloc(n * sizeof(char));
+      if (term == NULL)
+	{
+	  perror("malloc");
+	  sleep(ERROR_SLEEP);
+	  _exit(1);
+	}
+      for (i = 0; i < n; i++)
+	*(term + i) = *(_term + i);
+    }
+  
+  if (preserve_env == 0)
+    {
+      environ = malloc(sizeof(char*));
+      if (environ == NULL)
+	{
+	  perror("malloc");
+	  sleep(ERROR_SLEEP);
+	  _exit(1);
+	}
+      *environ = NULL;
+    }
+  
+  setenv("HOME", entry->pw_dir, 1);
+  setenv("USER", entry->pw_name, 1);
+  setenv("LOGUSER", entry->pw_name, 1);
+  setenv("SHELL", entry->pw_shell, 1);
+  setenv("TERM", term ?: DEFAULT_TERM, 1);
+  setenv("PATH", entry->pw_uid ? PATH : PATH_ROOT, 1);
+  
+  if (term)
+    free(term);
+}
+