telnetd: move generic stuff into libbb. It will make it easy

to make other server applets IPv6-aware too.

4 files changed, 168 insertions, 80 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 1c82cbb..c30c5a7 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -226,6 +226,7 @@ extern int xopen3(const char *pathname, int flags, int mode);
 extern off_t xlseek(int fd, off_t offset, int whence);
 extern off_t fdlength(int fd);
 
+
 extern int xsocket(int domain, int type, int protocol);
 extern void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen);
 extern void xlisten(int s, int backlog);
@@ -233,6 +234,17 @@ extern void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen);
 extern int xconnect_tcp_v4(struct sockaddr_in *s_addr);
 extern struct hostent *xgethostbyname(const char *name);
 extern struct hostent *xgethostbyname2(const char *name, int af);
+extern int xsocket_stream_ip4or6(sa_family_t *fp);
+typedef union {
+	struct sockaddr sa;
+	struct sockaddr_in sin;
+#if ENABLE_FEATURE_IPV6
+	struct sockaddr_in6 sin6;
+#endif
+} sockaddr_inet;
+extern int dotted2sockaddr(const char *dotted, struct sockaddr* sp, int socklen);
+extern int create_and_bind_socket_ip4or6(const char *hostaddr, int port);
+
 
 extern char *xstrdup(const char *s);
 extern char *xstrndup(const char *s, int n);
diff --git a/libbb/xconnect.c b/libbb/xconnect.c
index 21ec276..cf1f9d5 100644
--- a/libbb/xconnect.c
+++ b/libbb/xconnect.c
@@ -66,3 +66,155 @@ int xconnect_tcp_v4(struct sockaddr_in *s_addr)
 	xconnect(s, (struct sockaddr*) s_addr, sizeof(*s_addr));
 	return s;
 }
+
+int dotted2sockaddr(const char *dotted, struct sockaddr* sp, int socklen)
+{
+	union {
+		struct in_addr a4;
+#if ENABLE_FEATURE_IPV6
+		struct in6_addr a6;
+#endif
+	} a;
+
+	/* TODO maybe: port spec? like n.n.n.n:nn */
+
+#if ENABLE_FEATURE_IPV6
+	if (socklen >= sizeof(struct sockaddr_in6)
+	 && inet_pton(AF_INET6, dotted, &a.a6) > 0
+	) {
+		((struct sockaddr_in6*)sp)->sin6_family = AF_INET6;
+		((struct sockaddr_in6*)sp)->sin6_addr = a.a6;
+		/* ((struct sockaddr_in6*)sp)->sin6_port = */
+		return 0; /* success */
+	}
+#endif
+	if (socklen >= sizeof(struct sockaddr_in)
+	 && inet_pton(AF_INET, dotted, &a.a4) > 0
+	) {
+		((struct sockaddr_in*)sp)->sin_family = AF_INET;
+		((struct sockaddr_in*)sp)->sin_addr = a.a4;
+		/* ((struct sockaddr_in*)sp)->sin_port = */
+		return 0; /* success */
+	}
+	return 1;
+}
+
+int xsocket_stream_ip4or6(sa_family_t *fp)
+{
+	int fd;
+#if ENABLE_FEATURE_IPV6
+	fd = socket(AF_INET6, SOCK_STREAM, 0);
+	if (fp) *fp = AF_INET6;
+	if (fd < 0)
+#endif
+	{
+		fd = xsocket(AF_INET, SOCK_STREAM, 0);
+		if (fp) *fp = AF_INET;
+	}
+	return fd;
+}
+
+int create_and_bind_socket_ip4or6(const char *hostaddr, int port)
+{
+	static const int on = 1;
+	int fd;
+	sockaddr_inet sa;
+
+	memset(&sa, 0, sizeof(sa));
+	if (hostaddr && dotted2sockaddr(hostaddr, &sa.sa, sizeof(sa)))
+		bb_show_usage();
+
+	if (!sa.sa.sa_family)
+		fd = xsocket_stream_ip4or6(&sa.sa.sa_family);
+	else /* user specified bind addr dictates family */
+		fd = xsocket(sa.sa.sa_family, SOCK_STREAM, 0);
+	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+
+	/* if (port >= 0) { */
+#if ENABLE_FEATURE_IPV6
+		if (sa.sa.sa_family == AF_INET6 /* && !sa.sin6.sin6_port */)
+			sa.sin6.sin6_port = htons(port);
+#endif
+		if (sa.sa.sa_family == AF_INET /* && !sa.sin.sin_port */)
+			sa.sin.sin_port = htons(port);
+	/* } */
+
+	xbind(fd, &sa.sa, sizeof(sa));
+	return fd;
+}
+
+int dotted2sockaddr(const char *dotted, struct sockaddr* sp, int socklen)
+{
+	union {
+		struct in_addr a4;
+#if ENABLE_FEATURE_IPV6
+		struct in6_addr a6;
+#endif
+	} a;
+
+	/* TODO maybe: port spec? like n.n.n.n:nn */
+
+#if ENABLE_FEATURE_IPV6
+	if (socklen >= sizeof(struct sockaddr_in6)
+	 && inet_pton(AF_INET6, dotted, &a.a6) > 0
+	) {
+		((struct sockaddr_in6*)sp)->sin6_family = AF_INET6;
+		((struct sockaddr_in6*)sp)->sin6_addr = a.a6;
+		/* ((struct sockaddr_in6*)sp)->sin6_port = */
+		return 0; /* success */
+	}
+#endif
+	if (socklen >= sizeof(struct sockaddr_in)
+	 && inet_pton(AF_INET, dotted, &a.a4) > 0
+	) {
+		((struct sockaddr_in*)sp)->sin_family = AF_INET;
+		((struct sockaddr_in*)sp)->sin_addr = a.a4;
+		/* ((struct sockaddr_in*)sp)->sin_port = */
+		return 0; /* success */
+	}
+	return 1;
+}
+
+int xsocket_stream_ip4or6(sa_family_t *fp)
+{
+	int fd;
+#if ENABLE_FEATURE_IPV6
+	fd = socket(AF_INET6, SOCK_STREAM, 0);
+	if (fp) *fp = AF_INET6;
+	if (fd < 0)
+#endif
+	{
+		fd = xsocket(AF_INET, SOCK_STREAM, 0);
+		if (fp) *fp = AF_INET;
+	}
+	return fd;
+}
+
+int create_and_bind_socket_ip4or6(const char *hostaddr, int port)
+{
+	static const int on = 1;
+	int fd;
+	sockaddr_inet sa;
+
+	memset(&sa, 0, sizeof(sa));
+	if (hostaddr) {
+		if (dotted2sockaddr(hostaddr, &sa.sa, sizeof(sa)))
+			bb_error_msg_and_die("bad address '%s'", hostaddr);
+		/* user specified bind addr dictates family */
+		fd = xsocket(sa.sa.sa_family, SOCK_STREAM, 0);
+	} else 
+		fd = xsocket_stream_ip4or6(&sa.sa.sa_family);
+	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+
+	/* if (port >= 0) { */
+#if ENABLE_FEATURE_IPV6
+		if (sa.sa.sa_family == AF_INET6 /* && !sa.sin6.sin6_port */)
+			sa.sin6.sin6_port = htons(port);
+#endif
+		if (sa.sa.sa_family == AF_INET /* && !sa.sin.sin_port */)
+			sa.sin.sin_port = htons(port);
+	/* } */
+
+	xbind(fd, &sa.sa, sizeof(sa));
+	return fd;
+}
diff --git a/networking/fakeidentd.c b/networking/fakeidentd.c
index 18e86c5..0e543e7 100644
--- a/networking/fakeidentd.c
+++ b/networking/fakeidentd.c
@@ -110,13 +110,13 @@ static void handlexitsigs(int signum)
 /* May succeed. If not, won't care. */
 static void writepid(uid_t nobody, uid_t nogrp)
 {
-	char buf[24];
+	char buf[sizeof(int)*3 + 2];
 	int fd = open(PIDFILE, O_WRONLY|O_CREAT|O_TRUNC, 0664);
 
 	if (fd < 0)
 		return;
 
-	snprintf(buf, 23, "%d\n", getpid());
+	sprintf(buf, "%d\n", getpid());
 	write(fd, buf, strlen(buf));
 	fchown(fd, nobody, nogrp);
 	close(fd);
diff --git a/networking/telnetd.c b/networking/telnetd.c
index d524ac8..604f65c 100644
--- a/networking/telnetd.c
+++ b/networking/telnetd.c
@@ -354,87 +354,10 @@ free_session(struct tsession *ts)
 	}
 }
 
-static int
-dotted2sockaddr(const char *dotted, struct sockaddr* sp, int socklen)
-{
-	union {
-		struct in_addr a4;
-#if ENABLE_FEATURE_IPV6
-		struct in6_addr a6;
-#endif
-	} a;
-
-#if ENABLE_FEATURE_IPV6
-	if (socklen >= sizeof(struct sockaddr_in6)
-	 && inet_pton(AF_INET6, dotted, &a) > 0
-	) {
-		((struct sockaddr_in6*)sp)->sin6_family = AF_INET6;
-		((struct sockaddr_in6*)sp)->sin6_addr = a.a6;
-	} else
-#endif
-	if (socklen >= sizeof(struct sockaddr_in)
-	 && inet_pton(AF_INET, dotted, &a) > 0
-	) {
-		((struct sockaddr_in*)sp)->sin_family = AF_INET;
-		((struct sockaddr_in*)sp)->sin_addr = a.a4;
-	} else
-		return 1;
-
-	return 0; /* success */
-}
-
-static int
-xsocket_stream_ip4or6(sa_family_t *fp)
-{
-	int fd = socket(AF_INET6, SOCK_STREAM, 0);
-	if (fp) *fp = AF_INET6;
-	if (fd < 0) {
-		fd = xsocket(AF_INET, SOCK_STREAM, 0);
-		if (fp) *fp = AF_INET;
-	}
-	return fd;
-}
-
-static int
-create_socket(const char *hostaddr, int port)
-{
-	static const int on = 1;
-	int fd;
-	union {
-		struct sockaddr sa;
-		struct sockaddr_in sin;
-#if ENABLE_FEATURE_IPV6
-		struct sockaddr_in6 sin6;
-#endif
-	} sa;
-
-	memset(&sa, 0, sizeof(sa));
-	if (hostaddr && dotted2sockaddr(hostaddr, &sa.sa, sizeof(sa)))
-		bb_show_usage();
-
-	if (!sa.sa.sa_family)
-		fd = xsocket_stream_ip4or6(&sa.sa.sa_family);
-	else /* user specified -b ADDR dictates family */
-		fd = xsocket(sa.sa.sa_family, SOCK_STREAM, 0);
-	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
-
-#if ENABLE_FEATURE_IPV6
-	if (sa.sa.sa_family == AF_INET6)
-		sa.sin6.sin6_port = htons(port);
-#endif
-	if (sa.sa.sa_family == AF_INET)
-		sa.sin.sin_port = htons(port);
-
-	xbind(fd, &sa.sa, sizeof(sa));
-	xlisten(fd, 1);
-	return fd;
-}
-
 #else /* !FEATURE_TELNETD_STANDALONE */
 
 /* Never actually called */
 void free_session(struct tsession *ts);
-int create_socket(const char *hostaddr, int port);
 
 #endif
 
@@ -491,7 +414,8 @@ telnetd_main(int argc, char **argv)
 	if (IS_INETD) {
 		sessions = make_new_session(0, 1);
 	} else {
-		master_fd = create_socket(opt_bindaddr, portnbr);
+		master_fd = create_and_bind_socket_ip4or6(opt_bindaddr, portnbr);
+		xlisten(master_fd, 1);
 		if (!(opt & OPT_FOREGROUND))
 			xdaemon(0, 0);
 	}