Initial revision

git-svn-id: http://opensvn.csie.org/pttbbs/pttbbs/trunk/pttbbs@1 63ad8ddf-47c3-0310-b6dd-a9e9d9715204

1 files changed, 144 insertions, 0 deletions

diff --git a/innbbsd/rfc931.c b/innbbsd/rfc931.c
new file mode 100644
index 00000000..0d59d771
--- /dev/null
+++ b/innbbsd/rfc931.c
@@ -0,0 +1,144 @@
+ /*
+  * rfc931_user() speaks a common subset of the RFC 931, AUTH, TAP and IDENT
+  * protocols. It consults an RFC 931 etc. compatible daemon on the client
+  * host to look up the remote user name. The information should not be used
+  * for authentication purposes.
+  * 
+  * Diagnostics are reported through syslog(3).
+  * 
+  * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+  * 
+  * Inspired by the authutil package (comp.sources.unix volume 22) by Dan
+  * Bernstein (brnstnd@kramden.acf.nyu.edu).
+  */
+
+#ifndef lint
+static char sccsid[] = "@(#) rfc931.c 1.4 93/03/07 22:47:52";
+#endif
+
+#include <stdio.h>
+#include <syslog.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <setjmp.h>
+#include <signal.h>
+
+/*#include "log_tcp.h"*/
+
+#define	RFC931_PORT	113		/* Semi-well-known port */
+
+#ifndef RFC931_TIMEOUT
+#define	RFC931_TIMEOUT	30		/* wait for at most 30 seconds */
+#endif
+
+extern char *strchr();
+extern char *inet_ntoa();
+
+static jmp_buf timebuf;
+
+/* timeout - handle timeouts */
+
+static void timeout(sig)
+int     sig;
+{
+    longjmp(timebuf, sig);
+}
+
+/* rfc931_name - return remote user name */
+
+char   *my_rfc931_name(herefd,there)
+int herefd;
+struct sockaddr_in *there;		/* remote link information */
+{
+    struct sockaddr_in here;	/* local link information */
+    struct sockaddr_in sin;		/* for talking to RFC931 daemon */
+    int     length;
+    int     s;
+    unsigned remote;
+    unsigned local;
+    static char user[256];		/* XXX */
+    char    buffer[512];		/* YYY */
+    FILE   *fp;
+    char   *cp;
+    char   *result = "unknown";
+
+    /* Find out local address and port number of stdin. */
+
+    length = sizeof(here);
+    if (getsockname(herefd, (struct sockaddr *) & here, &length) == -1) {
+	syslog(LOG_ERR, "getsockname: %m");
+	return (result);
+    }
+
+    /*
+     * The socket that will be used for user name lookups should be bound to
+     * the same local IP address as stdin. This will automagically happen on
+     * hosts that have only one IP network address. When the local host has
+     * more than one IP network address, we must do an explicit bind() call.
+     */
+
+    if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1)
+	return (result);
+
+    sin = here;
+    sin.sin_port = 0;
+    if (bind(s, (struct sockaddr *) & sin, sizeof sin) < 0) {
+	syslog(LOG_ERR, "bind: %s: %m", inet_ntoa(here.sin_addr));
+	return (result);
+    }
+    /* Set up timer so we won't get stuck. */
+
+    signal(SIGALRM, timeout);
+    if (setjmp(timebuf)) {
+	close(s);				/* not: fclose(fp) */
+	return (result);
+    }
+    alarm(RFC931_TIMEOUT);
+
+    /* Connect to the RFC931 daemon. */
+
+    sin = *there;
+    sin.sin_port = htons(RFC931_PORT);
+    if (connect(s, (struct sockaddr *) & sin, sizeof(sin)) == -1
+	|| (fp = fdopen(s, "w+")) == 0) {
+	close(s);
+	alarm(0);
+	return (result);
+    }
+
+    /*
+     * Use unbuffered I/O or we may read back our own query. setbuf() must be
+     * called before doing any I/O on the stream. Thanks for the reminder,
+     * Paul Kranenburg <pk@cs.few.eur.nl>!
+     */
+
+    setbuf(fp, (char *) 0);
+
+    /* Query the RFC 931 server. Would 13-byte writes ever be broken up? */
+
+    fprintf(fp, "%u,%u\r\n", ntohs(there->sin_port), ntohs(here.sin_port));
+    fflush(fp);
+
+    /*
+     * Read response from server. Use fgets()/sscanf() instead of fscanf()
+     * because there is no buffer for pushback. Thanks, Chris Turbeville
+     * <turbo@cse.uta.edu>.
+     */
+
+    if (fgets(buffer, sizeof(buffer), fp) != 0
+	&& ferror(fp) == 0 && feof(fp) == 0
+	&& sscanf(buffer, "%u , %u : USERID :%*[^:]:%255s",
+		  &remote, &local, user) == 3
+	&& ntohs(there->sin_port) == remote
+	&& ntohs(here.sin_port) == local) {
+	/* Strip trailing carriage return. */
+
+	if (cp = strchr(user, '\r'))
+	    *cp = 0;
+	result = user;
+    }
+    alarm(0);
+    fclose(fp);
+    return (result);
+}