1 /* vi: set sw=4 ts=4: */
5 * Copyright (C) 2007 Denis Vlasenko
7 * Licensed under GPL version 2, see file LICENSE in this tarball for details.
14 enum { TIMEOUT = 20 };
16 /* Why use alarm(TIMEOUT-1)?
17 * isrv's internal select() will run with timeout=TIMEOUT.
18 * If nothing happens during TIMEOUT-1 seconds (no accept/read),
19 * then ALL sessions timed out by now. Instead of closing them one-by-one
20 * (isrv calls do_timeout for each 'stale' session),
21 * SIGALRM triggered by alarm(TIMEOUT-1) will kill us, terminating them all.
24 typedef struct identd_buf_t {
27 char buf[64 - 2*sizeof(int)];
30 static const char *bogouser = "nobody";
32 static int new_peer(isrv_state_t *state, int fd)
35 identd_buf_t *buf = xzalloc(sizeof(*buf));
39 peer = isrv_register_peer(state, buf);
41 return 0; /* failure */
42 if (isrv_register_fd(state, peer, fd) < 0)
43 return peer; /* failure, unregister peer */
45 buf->fd_flag = fcntl(fd, F_GETFL, 0) | O_NONBLOCK;
46 isrv_want_rd(state, fd);
50 static int do_rd(int fd, void **paramp)
52 identd_buf_t *buf = *paramp;
58 cur = buf->buf + buf->pos;
60 fcntl(fd, F_SETFL, buf->fd_flag | O_NONBLOCK);
61 sz = safe_read(fd, cur, sizeof(buf->buf) - buf->pos);
65 goto term; /* terminate this session if !EAGAIN */
70 buf->buf[buf->pos] = '\0';
71 p = strpbrk(cur, "\r\n");
74 if (p || !sz || buf->pos == sizeof(buf->buf)) {
75 /* fd is still in nonblocking mode - we never block here */
76 fdprintf(fd, "%s : USERID : UNIX : %s\r\n", buf->buf, bogouser);
80 fcntl(fd, F_SETFL, buf->fd_flag & ~O_NONBLOCK);
83 fcntl(fd, F_SETFL, buf->fd_flag & ~O_NONBLOCK);
88 static int do_timeout(void **paramp)
90 return 1; /* terminate session */
93 static void inetd_mode(void)
95 identd_buf_t *buf = xzalloc(sizeof(*buf));
96 /* We do NOT want nonblocking I/O here! */
97 buf->fd_flag = fcntl(0, F_GETFL, 0);
98 while (do_rd(0, (void*)&buf) == 0) /* repeat */;
101 int fakeidentd_main(int argc, char **argv)
104 OPT_foreground = 0x1,
111 const char *bind_address = NULL;
115 opt = getopt32(argc, argv, "fiwb:", &bind_address);
117 bogouser = argv[optind];
119 /* Daemonize if no -f or -i or -w */
120 bb_sanitize_stdio(!(opt & OPT_nodeamon));
121 if (!(opt & OPT_nodeamon)) {
122 openlog(applet_name, 0, LOG_DAEMON);
123 logmode = LOGMODE_SYSLOG;
126 if (opt & OPT_inetd) {
131 /* Ignore closed connections when writing */
132 signal(SIGPIPE, SIG_IGN);
134 if (opt & OPT_inetdwait) {
137 fd = create_and_bind_stream_or_die(bind_address,
138 bb_lookup_port("identd", "tcp", 113));
142 isrv_run(fd, new_peer, do_rd, NULL, do_timeout, TIMEOUT, 1);