postprivparent.c
上传用户:ig0539
上传日期:2022-05-21
资源大小:181k
文件大小:4k
- /*
- * Part of Very Secure FTPd
- * Licence: GPL v2
- * Author: Chris Evans
- * postprivparent.c
- *
- * This file contains all privileged parent services offered after logging
- * in. This includes e.g. chown() of uploaded files, issuing of port 20
- * sockets.
- */
- #include "postprivparent.h"
- #include "session.h"
- #include "privops.h"
- #include "privsock.h"
- #include "utility.h"
- #include "tunables.h"
- #include "defs.h"
- #include "sysutil.h"
- #include "str.h"
- #include "secutil.h"
- #include "sysstr.h"
- #include "sysdeputil.h"
- static void minimize_privilege(struct vsf_session* p_sess);
- static void process_post_login_req(struct vsf_session* p_sess);
- static void cmd_process_chown(struct vsf_session* p_sess);
- static void cmd_process_get_data_sock(struct vsf_session* p_sess);
- static void cmd_process_pasv_cleanup(struct vsf_session* p_sess);
- static void cmd_process_pasv_active(struct vsf_session* p_sess);
- static void cmd_process_pasv_listen(struct vsf_session* p_sess);
- static void cmd_process_pasv_accept(struct vsf_session* p_sess);
- void
- vsf_priv_parent_postlogin(struct vsf_session* p_sess)
- {
- minimize_privilege(p_sess);
- /* We're still here... */
- while (1)
- {
- process_post_login_req(p_sess);
- }
- }
- static void
- process_post_login_req(struct vsf_session* p_sess)
- {
- char cmd;
- /* Blocks */
- cmd = priv_sock_get_cmd(p_sess->parent_fd);
- if (tunable_chown_uploads && cmd == PRIV_SOCK_CHOWN)
- {
- cmd_process_chown(p_sess);
- }
- else if (cmd == PRIV_SOCK_GET_DATA_SOCK)
- {
- cmd_process_get_data_sock(p_sess);
- }
- else if (cmd == PRIV_SOCK_PASV_CLEANUP)
- {
- cmd_process_pasv_cleanup(p_sess);
- }
- else if (cmd == PRIV_SOCK_PASV_ACTIVE)
- {
- cmd_process_pasv_active(p_sess);
- }
- else if (cmd == PRIV_SOCK_PASV_LISTEN)
- {
- cmd_process_pasv_listen(p_sess);
- }
- else if (cmd == PRIV_SOCK_PASV_ACCEPT)
- {
- cmd_process_pasv_accept(p_sess);
- }
- else
- {
- die("bad request in process_post_login_req");
- }
- }
- static void
- minimize_privilege(struct vsf_session* p_sess)
- {
- /* So, we logged in and forked a totally unprivileged child. Our job
- * now is to minimize the privilege we need in order to act as a helper
- * to the child.
- */
- if (!p_sess->is_anonymous && tunable_session_support)
- {
- /* Need to hang around to update logs, utmp, wtmp etc. on logout.
- * Need to keep privs to do this. */
- return;
- }
- {
- unsigned int caps = 0;
- struct mystr user_str = INIT_MYSTR;
- struct mystr dir_str = INIT_MYSTR;
- str_alloc_text(&user_str, tunable_nopriv_user);
- str_alloc_text(&dir_str, tunable_secure_chroot_dir);
- if (tunable_chown_uploads)
- {
- caps |= kCapabilityCAP_CHOWN;
- }
- if (tunable_connect_from_port_20)
- {
- caps |= kCapabilityCAP_NET_BIND_SERVICE;
- }
- vsf_secutil_change_credentials(&user_str, &dir_str, 0, caps,
- VSF_SECUTIL_OPTION_CHROOT);
- str_free(&user_str);
- str_free(&dir_str);
- }
- }
- static void
- cmd_process_chown(struct vsf_session* p_sess)
- {
- int the_fd = priv_sock_recv_fd(p_sess->parent_fd);
- vsf_privop_do_file_chown(p_sess, the_fd);
- vsf_sysutil_close(the_fd);
- priv_sock_send_result(p_sess->parent_fd, PRIV_SOCK_RESULT_OK);
- }
- static void
- cmd_process_get_data_sock(struct vsf_session* p_sess)
- {
- unsigned short port = (unsigned short) priv_sock_get_int(p_sess->parent_fd);
- int sock_fd = vsf_privop_get_ftp_port_sock(p_sess, port);
- if (sock_fd == -1)
- {
- priv_sock_send_result(p_sess->parent_fd, PRIV_SOCK_RESULT_BAD);
- return;
- }
- priv_sock_send_result(p_sess->parent_fd, PRIV_SOCK_RESULT_OK);
- priv_sock_send_fd(p_sess->parent_fd, sock_fd);
- vsf_sysutil_close(sock_fd);
- }
- static void
- cmd_process_pasv_cleanup(struct vsf_session* p_sess)
- {
- vsf_privop_pasv_cleanup(p_sess);
- priv_sock_send_result(p_sess->parent_fd, PRIV_SOCK_RESULT_OK);
- }
- static void
- cmd_process_pasv_active(struct vsf_session* p_sess)
- {
- int active = vsf_privop_pasv_active(p_sess);
- priv_sock_send_int(p_sess->parent_fd, active);
- }
- static void
- cmd_process_pasv_listen(struct vsf_session* p_sess)
- {
- unsigned short port = vsf_privop_pasv_listen(p_sess);
- priv_sock_send_int(p_sess->parent_fd, port);
- }
- static void
- cmd_process_pasv_accept(struct vsf_session* p_sess)
- {
- int fd = vsf_privop_accept_pasv(p_sess);
- if (fd < 0)
- {
- priv_sock_send_result(p_sess->parent_fd, PRIV_SOCK_RESULT_BAD);
- priv_sock_send_int(p_sess->parent_fd, fd);
- return;
- }
- priv_sock_send_result(p_sess->parent_fd, PRIV_SOCK_RESULT_OK);
- priv_sock_send_fd(p_sess->parent_fd, fd);
- vsf_sysutil_close(fd);
- }