1 files changed, 147 insertions, 0 deletions
diff --git a/release/src/router/busybox/networking/isrv_identd.c b/release/src/router/busybox/networking/isrv_identd.c
new file mode 100644
index 00000000..e8ba0076
--- /dev/null
+++ b/release/src/router/busybox/networking/isrv_identd.c
@@ -0,0 +1,147 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Fake identd server.
+ *
+ * Copyright (C) 2007 Denys Vlasenko
+ *
+ * Licensed under GPL version 2, see file LICENSE in this tarball for details.
+ */
+
+#include "libbb.h"
+#include <syslog.h>
+#include "isrv.h"
+
+enum { TIMEOUT = 20 };
+
+typedef struct identd_buf_t {
+	int pos;
+	int fd_flag;
+	char buf[64 - 2*sizeof(int)];
+} identd_buf_t;
+
+#define bogouser bb_common_bufsiz1
+
+static int new_peer(isrv_state_t *state, int fd)
+{
+	int peer;
+	identd_buf_t *buf = xzalloc(sizeof(*buf));
+
+	peer = isrv_register_peer(state, buf);
+	if (peer < 0)
+		return 0; /* failure */
+	if (isrv_register_fd(state, peer, fd) < 0)
+		return peer; /* failure, unregister peer */
+
+	buf->fd_flag = fcntl(fd, F_GETFL) | O_NONBLOCK;
+	isrv_want_rd(state, fd);
+	return 0;
+}
+
+static int do_rd(int fd, void **paramp)
+{
+	identd_buf_t *buf = *paramp;
+	char *cur, *p;
+	int retval = 0; /* session is ok (so far) */
+	int sz;
+
+	cur = buf->buf + buf->pos;
+
+	if (buf->fd_flag & O_NONBLOCK)
+		fcntl(fd, F_SETFL, buf->fd_flag);
+	sz = safe_read(fd, cur, sizeof(buf->buf) - buf->pos);
+
+	if (sz < 0) {
+		if (errno != EAGAIN)
+			goto term; /* terminate this session if !EAGAIN */
+		goto ok;
+	}
+
+	buf->pos += sz;
+	buf->buf[buf->pos] = '\0';
+	p = strpbrk(cur, "\r\n");
+	if (p)
+		*p = '\0';
+	if (!p && sz && buf->pos <= (int)sizeof(buf->buf))
+		goto ok;
+	/* Terminate session. If we are in server mode, then
+	 * fd is still in nonblocking mode - we never block here */
+	if (fd == 0) fd++; /* inetd mode? then write to fd 1 */
+	fdprintf(fd, "%s : USERID : UNIX : %s\r\n", buf->buf, bogouser);
+ term:
+	free(buf);
+	retval = 1; /* terminate */
+ ok:
+	if (buf->fd_flag & O_NONBLOCK)
+		fcntl(fd, F_SETFL, buf->fd_flag & ~O_NONBLOCK);
+	return retval;
+}
+
+static int do_timeout(void **paramp UNUSED_PARAM)
+{
+	return 1; /* terminate session */
+}
+
+static void inetd_mode(void)
+{
+	identd_buf_t *buf = xzalloc(sizeof(*buf));
+	/* buf->pos = 0; - xzalloc did it */
+	/* We do NOT want nonblocking I/O here! */
+	/* buf->fd_flag = 0; - xzalloc did it */
+	do
+		alarm(TIMEOUT);
+	while (do_rd(0, (void*)&buf) == 0);
+}
+
+int fakeidentd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int fakeidentd_main(int argc UNUSED_PARAM, char **argv)
+{
+	enum {
+		OPT_foreground = 0x1,
+		OPT_inetd      = 0x2,
+		OPT_inetdwait  = 0x4,
+		OPT_fiw        = 0x7,
+		OPT_bindaddr   = 0x8,
+	};
+
+	const char *bind_address = NULL;
+	unsigned opt;
+	int fd;
+
+	opt = getopt32(argv, "fiwb:", &bind_address);
+	strcpy(bogouser, "nobody");
+	if (argv[optind])
+		strncpy(bogouser, argv[optind], sizeof(bogouser));
+
+	/* Daemonize if no -f and no -i and no -w */
+	if (!(opt & OPT_fiw))
+		bb_daemonize_or_rexec(0, argv);
+
+	/* Where to log in inetd modes? "Classic" inetd
+	 * probably has its stderr /dev/null'ed (we need log to syslog?),
+	 * but daemontools-like utilities usually expect that children
+	 * log to stderr. I like daemontools more. Go their way.
+	 * (Or maybe we need yet another option "log to syslog") */
+	if (!(opt & OPT_fiw) /* || (opt & OPT_syslog) */) {
+		openlog(applet_name, LOG_PID, LOG_DAEMON);
+		logmode = LOGMODE_SYSLOG;
+	}
+
+	if (opt & OPT_inetd) {
+		inetd_mode();
+		return 0;
+	}
+
+	/* Ignore closed connections when writing */
+	signal(SIGPIPE, SIG_IGN);
+
+	fd = 0;
+	if (!(opt & OPT_inetdwait)) {
+		fd = create_and_bind_stream_or_die(bind_address,
+				bb_lookup_port("identd", "tcp", 113));
+		xlisten(fd, 5);
+	}
+
+	isrv_run(fd, new_peer, do_rd, /*do_wr:*/ NULL, do_timeout,
+			TIMEOUT, (opt & OPT_inetdwait) ? TIMEOUT : 0);
+	return 0;
+}