Add pwent(3).

libc/Makefile

@@ -225,6 +225,7 @@ popen.o \
 ppoll.o \
 print.o \
 putc.o \
+pwent.o \
 raise.o \
 rand.o \
 readdirents.o \

libc/include/pwd.h

@@ -0,0 +1,57 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library 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 Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    pwd.h
+    User database.
+
+*******************************************************************************/
+
+#ifndef INCLUDE_PWD_H
+#define INCLUDE_PWD_H
+
+#include <features.h>
+
+__BEGIN_DECLS
+
+@include(gid_t.h)
+@include(uid_t.h)
+@include(size_t.h)
+
+#define _PASSWD_BUFFER_SIZE 64
+
+struct passwd
+{
+	char pw_name[_PASSWD_BUFFER_SIZE];
+	char pw_dir[_PASSWD_BUFFER_SIZE];
+	char pw_shell[_PASSWD_BUFFER_SIZE];
+	uid_t pw_uid;
+	gid_t pw_gid;
+};
+
+void endpwent(void);
+struct passwd* getpwent(void);
+struct passwd* getpwnam(const char*);
+int getpwnam_r(const char*, struct passwd*, char*, size_t, struct passwd**);
+struct passwd* getpwuid(uid_t);
+int getpwuid_r(uid_t, struct passwd *, char*, size_t, struct passwd**);
+void setpwent(void);
+
+__END_DECLS
+
+#endif

libc/pwent.cpp

@@ -0,0 +1,123 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library 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 Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    pwent.cpp
+    User database.
+
+*******************************************************************************/
+
+#include <sys/types.h>
+
+#include <pwd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+// TODO: This implementation of pwent is very hacky and insecure.
+
+const char* const ROOT_UID = "0";
+const char* const ROOT_GID = "0";
+const char* const ROOT_NAME = "root";
+const char* const ROOT_HOME = "/root";
+const char* const ROOT_SHELL = "sh";
+
+static struct passwd global_passwd;
+
+static size_t global_user_offset = 0;
+
+extern "C" void setpwent(void)
+{
+	global_user_offset = 0;
+}
+
+extern "C" void endpwent(void)
+{
+}
+
+static const char* getenv_def(const char* key, const char* def)
+{
+	const char* value = getenv(key);
+	return value ? value : def;
+}
+
+static struct passwd* fill_passwd(struct passwd* pw)
+{
+	// TODO: Potential buffer overflow.
+	strcpy(pw->pw_name, getenv_def("USERNAME", ROOT_NAME));
+	strcpy(pw->pw_dir, getenv_def("HOME", ROOT_HOME));
+	strcpy(pw->pw_shell, getenv_def("SHELL", ROOT_SHELL));
+	pw->pw_uid = atoi(getenv_def("USERID", ROOT_UID));
+	pw->pw_gid = atoi(getenv_def("GROUPID", ROOT_GID));
+	return pw;
+}
+
+static uid_t lookup_username(const char* name)
+{
+	const char* my_username = getenv("USERNAME") ? getenv("USERNAME") : "root";
+	if ( !strcmp(my_username, name) )
+		if ( getenv("USERID") )
+			return atoi(getenv("USERID"));
+	return atoi(ROOT_UID);
+}
+
+extern "C" struct passwd* getpwent(void)
+{
+	if ( global_user_offset == 1 )
+		return NULL;
+	global_user_offset++;
+	return fill_passwd(&global_passwd);
+}
+
+extern "C" struct passwd* getpwnam(const char* name)
+{
+	return getpwuid(lookup_username(name));
+}
+
+extern "C" int getpwnam_r(const char* name, struct passwd* pw, char* buf,
+                          size_t buflen, struct passwd** ret)
+{
+	return getpwuid_r(lookup_username(name), pw, buf, buflen, ret);
+}
+
+extern "C" struct passwd* getpwuid(uid_t uid)
+{
+	struct passwd* ret;
+	if ( getpwuid_r(uid, &global_passwd, NULL, 0, &ret) )
+		return NULL;
+	return ret;
+}
+
+extern "C" int getpwuid_r(uid_t uid, struct passwd* pw, char* buf,
+                          size_t buflen, struct passwd** ret)
+{
+	(void) buf;
+	(void) buflen;
+	fill_passwd(pw);
+	pw->pw_uid = uid;
+	*ret = pw;
+	return 0;
+}
+
+extern "C" char* getlogin()
+{
+	static char username[64];
+	// TODO: Potential buffer overflow.
+	strcpy(username, getenv("USERNAME") ? getenv("USERNAME") : ROOT_NAME);
+	return username;
+}